WO2021223057A1 - Selecting dual connectivity cell - Google Patents
Selecting dual connectivity cell Download PDFInfo
- Publication number
- WO2021223057A1 WO2021223057A1 PCT/CN2020/088582 CN2020088582W WO2021223057A1 WO 2021223057 A1 WO2021223057 A1 WO 2021223057A1 CN 2020088582 W CN2020088582 W CN 2020088582W WO 2021223057 A1 WO2021223057 A1 WO 2021223057A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- cell
- rat
- access
- nsa
- support
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W48/00—Access restriction; Network selection; Access point selection
- H04W48/20—Selecting an access point
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W48/00—Access restriction; Network selection; Access point selection
- H04W48/16—Discovering, processing access restriction or access information
Definitions
- aspects of the disclosure relate generally to wireless communications.
- Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G) , a second-generation (2G) digital wireless phone service (including interim 2.5G networks) , a third-generation (3G) high speed data, Internet-capable wireless service and a fourth-generation (4G) service (e.g., LTE or WiMax) .
- cellular and personal communications service (PCS) systems include the cellular Analog Advanced Mobile Phone System (AMPS) , and digital cellular systems based on code division multiple access (CDMA) , frequency division multiple access (FDMA) , time division multiple access (TDMA) , the Global System for Mobile communication (GSM) , etc.
- CDMA code division multiple access
- FDMA frequency division multiple access
- TDMA time division multiple access
- GSM Global System for Mobile communication
- a fifth generation (5G) wireless standard also referred to as New Radio (NR)
- NR New Radio
- the 5G standard according to the Next Generation Mobile Networks Alliance, is designed to provide data rates of several tens of megabits per second to each of tens of thousands of users, with 1 gigabit per second to tens of workers on an office floor.
- Several hundreds of thousands of simultaneous connections should be supported in order to support large wireless deployments. Consequently, the spectral efficiency of 5G mobile communications should be significantly enhanced compared to the current 4G standard.
- signaling efficiencies should be enhanced and latency should be substantially reduced compared to current standards.
- a method of wireless communication performed by a user equipment includes discovering a first cell operating in accordance with a first radio access technology (RAT) , determining that the first cell does not support non-standalone (NSA) access for a second RAT, and in response to determining that the first cell does not support NSA access for the second RAT, connecting to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
- RAT radio access technology
- NSA non-standalone
- a UE includes a memory, at least one transceiver, and at least one processor communicatively coupled the memory and the at least one transceiver, the at least one processor configured to: discover a first cell operating in accordance with a first RAT, determine that the first cell does not support NSA access for a second RAT, and connect, in response to a determination that the first cell does not support NSA access for the second RAT, to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
- a UE includes means for discovering a first cell operating in accordance with a first RAT, means for determining that the first cell does not support NSA access for a second RAT, and means for connecting, in response to determining that the first cell does not support NSA access for the second RAT, to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
- a non-transitory computer-readable medium storing computer-executable instructions includes computer-executable instructions comprising: at least one instruction instructing a UE to discover a first cell operating in accordance with a first RAT, at least one instruction instructing the UE to determine that the first cell does not support NSA access for a second RAT, and at least one instruction instructing the UE to connect, in response to determining that the first cell does not support NSA access for the second RAT, to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
- FIG. 1 illustrates an exemplary wireless communications system, according to aspects of the disclosure.
- FIG. 2A depicts a wireless communications system showing user plane connectivity supporting dual connectivity for a UE.
- FIG. 2B depicts a wireless communications system showing control plane connectivity supporting dual connectivity for the UE.
- FIG. 3A illustrates a control plane protocol architecture for dual connectivity.
- FIG. 3B is a block diagram illustrating an example user plane architecture for dual connectivity.
- FIGS. 4A to 4C are simplified block diagrams of several sample aspects of components that may be employed in a UE, a base station, and a network entity, respectively.
- FIG. 5 illustrates an exemplary method for selecting a cell capable of non-standalone dual connectivity, according to aspects of the disclosure.
- FIG. 6 illustrates an exemplary method of wireless communication, according to aspects of the disclosure.
- sequences of actions to be performed by, for example, elements of a computing device. It will be recognized that various actions described herein can be performed by specific circuits (e.g., application specific integrated circuits (ASICs) ) , by program instructions being executed by one or more processors, or by a combination of both. Additionally, the sequence (s) of actions described herein can be considered to be embodied entirely within any form of non-transitory computer-readable storage medium having stored therein a corresponding set of computer instructions that, upon execution, would cause or instruct an associated processor of a device to perform the functionality described herein.
- ASICs application specific integrated circuits
- a UE may be any wireless communication device (e.g., a mobile phone, router, tablet computer, laptop computer, tracking device, wearable (e.g., smartwatch, glasses, augmented reality (AR) /virtual reality (VR) headset, etc. ) , vehicle (e.g., automobile, motorcycle, bicycle, etc. ) , Internet of Things (IoT) device, etc. ) used by a user to communicate over a wireless communications network.
- wireless communication device e.g., a mobile phone, router, tablet computer, laptop computer, tracking device, wearable (e.g., smartwatch, glasses, augmented reality (AR) /virtual reality (VR) headset, etc. )
- vehicle e.g., automobile, motorcycle, bicycle, etc.
- IoT Internet of Things
- a UE may be mobile or may (e.g., at certain times) be stationary, and may communicate with a radio access network (RAN) .
- RAN radio access network
- the term “UE” may be referred to interchangeably as an “access terminal” or “AT, ” a “client device, ” a “wireless device, ” a “subscriber device, ” a “subscriber terminal, ” a “subscriber station, ” a “user terminal” or UT, a “mobile device, ” a “mobile terminal, ” a “mobile station, ” or variations thereof.
- UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected with external networks such as the Internet and with other UEs.
- external networks such as the Internet and with other UEs.
- other mechanisms of connecting to the core network and/or the Internet are also possible for the UEs, such as over wired access networks, wireless local area network (WLAN) networks (e.g., based on IEEE 802.11, etc. ) and so on.
- WLAN wireless local area network
- a base station may operate according to one of several RATs in communication with UEs depending on the network in which it is deployed, and may be alternatively referred to as an access point (AP) , a network node, a NodeB, an evolved NodeB (eNB) , a next generation eNB (ng-eNB) , a New Radio (NR) Node B (also referred to as a gNB or gNodeB) , etc.
- AP access point
- eNB evolved NodeB
- ng-eNB next generation eNB
- NR New Radio
- a base station may be used primarily to support wireless access by UEs, including supporting data, voice, and/or signaling connections for the supported UEs.
- a base station may provide purely edge node signaling functions while in other systems it may provide additional control and/or network management functions.
- a communication link through which UEs can send signals to a base station is called an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc. ) .
- a communication link through which the base station can send signals to UEs is called a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc. ) .
- DL downlink
- forward link channel e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.
- TCH traffic channel
- base station may refer to a single physical transmission-reception point (TRP) or to multiple physical TRPs that may or may not be co-located.
- TRP transmission-reception point
- the physical TRP may be an antenna of the base station corresponding to a cell (or several cell sectors) of the base station.
- base station refers to multiple co-located physical TRPs
- the physical TRPs may be an array of antennas (e.g., as in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming) of the base station.
- MIMO multiple-input multiple-output
- the physical TRPs may be a distributed antenna system (DAS) (anetwork of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (aremote base station connected to a serving base station) .
- DAS distributed antenna system
- RRH remote radio head
- the non-co-located physical TRPs may be the serving base station receiving the measurement report from the UE and a neighbor base station whose reference RF signals (or simply “reference signals” ) the UE is measuring. Because a TRP is the point from which a base station transmits and receives wireless signals, as used herein, references to transmission from or reception at a base station are to be understood as referring to a particular TRP of the base station.
- a base station may not support wireless access by UEs (e.g., may not support data, voice, and/or signaling connections for UEs) , but may instead transmit reference signals to UEs to be measured by the UEs, and/or may receive and measure signals transmitted by the UEs.
- a base station may be referred to as a positioning beacon (e.g., when transmitting signals to UEs) and/or as a location measurement unit (e.g., when receiving and measuring signals from UEs) .
- An “RF signal” comprises an electromagnetic wave of a given frequency that transports information through the space between a transmitter and a receiver.
- a transmitter may transmit a single “RF signal” or multiple “RF signals” to a receiver.
- the receiver may receive multiple “RF signals” corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through multipath channels.
- the same transmitted RF signal on different paths between the transmitter and receiver may be referred to as a “multipath” RF signal.
- an RF signal may also be referred to as a “wireless signal” or simply a “signal” where it is clear from the context that the term “signal” refers to a wireless signal or an RF signal.
- FIG. 1 illustrates an exemplary wireless communications system 100.
- the wireless communications system 100 (which may also be referred to as a wireless wide area network (WWAN) ) may include various base stations 102 and various UEs 104.
- the base stations 102 may include macro cell base stations (high power cellular base stations) and/or small cell base stations (low power cellular base stations) .
- the macro cell base station may include eNBs and/or ng-eNBs where the wireless communications system 100 corresponds to an LTE network, or gNBs where the wireless communications system 100 corresponds to a NR network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc.
- the base stations 102 may collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC) ) through backhaul links 122, and through the core network 170 to one or more application servers 172 (which may be part of core network 170 or may be external to core network 170) .
- a core network 170 e.g., an evolved packet core (EPC) or a 5G core (5GC)
- EPC evolved packet core
- 5GC 5G core
- the base stations 102 may perform functions that relate to one or more of transferring user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages.
- the base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC /5GC) over backhaul links 134, which may be wired or wireless.
- the base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. In an aspect, one or more cells may be supported by a base station 102 in each coverage area 110.
- a “cell” is a logical communication entity used for communication with a base station (e.g., over some frequency resource, referred to as a carrier frequency, component carrier, carrier, band, or the like) , and may be associated with an identifier (e.g., a physical cell identifier (PCI) , a virtual cell identifier (VCI) , a cell global identifier (CGI) ) for distinguishing cells operating via the same or a different carrier frequency.
- PCI physical cell identifier
- VCI virtual cell identifier
- CGI cell global identifier
- different cells may be configured according to different protocol types (e.g., machine-type communication (MTC) , narrowband IoT (NB-IoT) , enhanced mobile broadband (eMBB) , or others) that may provide access for different types of UEs.
- MTC machine-type communication
- NB-IoT narrowband IoT
- eMBB enhanced mobile broadband
- a cell may refer to either or both of the logical communication entity and the base station that supports it, depending on the context.
- TRP is typically the physical transmission point of a cell
- the terms “cell” and “TRP” may be used interchangeably.
- the term “cell” may also refer to a geographic coverage area of a base station (e.g., a sector) , insofar as a carrier frequency can be detected and used for communication within some portion of geographic coverage areas 110.
- While neighboring macro cell base station 102 geographic coverage areas 110 may partially overlap (e.g., in a handover region) , some of the geographic coverage areas 110 may be substantially overlapped by a larger geographic coverage area 110.
- a small cell base station 102' may have a coverage area 110'that substantially overlaps with the coverage area 110 of one or more macro cell base stations 102.
- a network that includes both small cell and macro cell base stations may be known as a heterogeneous network.
- a heterogeneous network may also include home eNBs (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) .
- HeNBs home eNBs
- CSG closed subscriber group
- the communication links 120 between the base stations 102 and the UEs 104 may include uplink (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (also referred to as forward link) transmissions from a base station 102 to a UE 104.
- the communication links 120 may use MIMO antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity.
- the communication links 120 may be through one or more carrier frequencies. Allocation of carriers may be asymmetric with respect to downlink and uplink (e.g., more or less carriers may be allocated for downlink than for uplink) .
- the wireless communications system 100 may further include a wireless local area network (WLAN) access point (AP) 150 in communication with WLAN stations (STAs) 152 via communication links 154 in an unlicensed frequency spectrum (e.g., 5 GHz) .
- WLAN STAs 152 and/or the WLAN AP 150 may perform a clear channel assessment (CCA) or listen before talk (LBT) procedure prior to communicating in order to determine whether the channel is available.
- CCA clear channel assessment
- LBT listen before talk
- the small cell base station 102' may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell base station 102'may employ LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum as used by the WLAN AP 150.
- NR in unlicensed spectrum may be referred to as NR-U.
- LTE in an unlicensed spectrum may be referred to as LTE-U, licensed assisted access (LAA) , or MulteFire.
- the wireless communications system 100 may further include a millimeter wave (mmW) base station 180 that may operate in mmW frequencies and/or near mmW frequencies in communication with a UE 182.
- Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in this band may be referred to as a millimeter wave.
- Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters.
- the super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave.
- the mmW base station 180 and the UE 182 may utilize beamforming (transmit and/or receive) over a mmW communication link 184 to compensate for the extremely high path loss and short range.
- one or more base stations 102 may also transmit using mmW or near mmW and beamforming. Accordingly, it will be appreciated that the foregoing illustrations are merely examples and should not be construed to limit the various aspects disclosed herein.
- Transmit beamforming is a technique for focusing an RF signal in a specific direction.
- a network node e.g., a base station
- transmit beamforming the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal for the receiving device (s) .
- a network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that are broadcasting the RF signal.
- a network node may use an array of antennas (referred to as a “phased array” or an “antenna array” ) that creates a beam of RF waves that can be “steered” to point in different directions, without actually moving the antennas.
- the RF current from the transmitter is fed to the individual antennas with the correct phase relationship so that the radio waves from the separate antennas add together to increase the radiation in a desired direction, while canceling to suppress radiation in undesired directions.
- Transmit beams may be quasi-collocated, meaning that they appear to the receiver (e.g., a UE) as having the same parameters, regardless of whether or not the transmitting antennas of the network node themselves are physically collocated.
- the receiver e.g., a UE
- QCL relation of a given type means that certain parameters about a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam.
- the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of a second reference RF signal transmitted on the same channel.
- the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type D, the receiver can use the source reference RF signal to estimate the spatial receive parameter of a second reference RF signal transmitted on the same channel.
- the receiver uses a receive beam to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting and/or adjust the phase setting of an array of antennas in a particular direction to amplify (e.g., to increase the gain level of) the RF signals received from that direction.
- a receiver is said to beamform in a certain direction, it means the beam gain in that direction is high relative to the beam gain along other directions, or the beam gain in that direction is the highest compared to the beam gain in that direction of all other receive beams available to the receiver.
- RSRP reference signal received power
- RSRQ reference signal received quality
- SINR signal-to-interference-plus-noise ratio
- Receive beams may be spatially related.
- a spatial relation means that parameters for a transmit beam for a second reference signal can be derived from information about a receive beam for a first reference signal.
- a UE may use a particular receive beam to receive one or more reference downlink reference signals (e.g., positioning reference signals (PRS) , navigation reference signals (NRS) , tracking reference signals (TRS) , phase tracking reference signal (PTRS) , cell-specific reference signals (CRS) , channel state information reference signals (CSI-RS) , primary synchronization signals (PSS) , secondary synchronization signals (SSS) , synchronization signal blocks (SSBs) , etc. ) from a base station.
- reference downlink reference signals e.g., positioning reference signals (PRS) , navigation reference signals (NRS) , tracking reference signals (TRS) , phase tracking reference signal (PTRS) , cell-specific reference signals (CRS) , channel state information reference signals (CSI-RS) , primary
- the UE can then form a transmit beam for sending one or more uplink reference signals (e.g., uplink positioning reference signals (UL-PRS) , sounding reference signal (SRS) , demodulation reference signals (DMRS) , PTRS, etc. ) to that base station based on the parameters of the receive beam.
- uplink reference signals e.g., uplink positioning reference signals (UL-PRS) , sounding reference signal (SRS) , demodulation reference signals (DMRS) , PTRS, etc.
- a “downlink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the downlink beam to transmit a reference signal to a UE, the downlink beam is a transmit beam. If the UE is forming the downlink beam, however, it is a receive beam to receive the downlink reference signal.
- an “uplink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the uplink beam, it is an uplink receive beam, and if a UE is forming the uplink beam, it is an uplink transmit beam.
- the frequency spectrum in which wireless nodes is divided into multiple frequency ranges, FR1 (from 450 to 6000 MHz) , FR2 (from 24250 to 52600 MHz) , FR3 (above 52600 MHz) , and FR4 (between FR1 and FR2) .
- FR1 from 450 to 6000 MHz
- FR2 from 24250 to 52600 MHz
- FR3 above 52600 MHz
- FR4 between FR1 and FR2
- one of the carrier frequencies is referred to as the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell, ” and the remaining carrier frequencies are referred to as “secondary carriers” or “secondary serving cells” or “SCells.
- the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by a UE 104/182 and the cell in which the UE 104/182 either performs the initial radio resource control (RRC) connection establishment procedure or initiates the RRC connection re-establishment procedure.
- the primary carrier carries all common and UE-specific control channels, and may be a carrier in a licensed frequency (however, this is not always the case) .
- a secondary carrier is a carrier operating on a second frequency (e.g., FR2) that may be configured once the RRC connection is established between the UE 104 and the anchor carrier and that may be used to provide additional radio resources.
- the secondary carrier may be a carrier in an unlicensed frequency.
- the secondary carrier may contain only necessary signaling information and signals, for example, those that are UE-specific may not be present in the secondary carrier, since both primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104/182 in a cell may have different downlink primary carriers. The same is true for the uplink primary carriers.
- the network is able to change the primary carrier of any UE 104/182 at any time. This is done, for example, to balance the load on different carriers.
- a “serving cell” (whether a PCell or an SCell) corresponds to a carrier frequency /component carrier over which some base station is communicating, the term “cell, ” “serving cell, ” “component carrier, ” “carrier frequency, ” and the like can be used interchangeably.
- one of the frequencies utilized by the macro cell base stations 102 may be an anchor carrier (or “PCell” ) and other frequencies utilized by the macro cell base stations 102 and/or the mmW base station 180 may be secondary carriers ( “SCells” ) .
- the simultaneous transmission and/or reception of multiple carriers enables the UE 104/182 to significantly increase its data transmission and/or reception rates. For example, two 20 MHz aggregated carriers in a multi-carrier system would theoretically lead to a two-fold increase in data rate (i.e., 40 MHz) , compared to that attained by a single 20 MHz carrier.
- the wireless communications system 100 may further include a UE 164 that may communicate with a macro cell base station 102 over a communication link 120 and/or the mmW base station 180 over a mmW communication link 184.
- the macro cell base station 102 may support a PCell and one or more SCells for the UE 164 and the mmW base station 180 may support one or more SCells for the UE 164.
- the macro cell base station 102 and the mmW base station 180 may be part of different RAN’s (e.g., an LTE network and an NR network, respectively) and/or operate in accordance with different RATs (e.g., LTE and NR, respectively) .
- UE 164 may be referred to as having “dual connectivity. ” Although only UE 164 is illustrated as having dual connectivity to macro cell base station 102 and the mmW base station 180, this is for simplicity, and any of the other UE’s may also be capable of dual connectivity.
- the wireless communications system 100 may further include one or more UEs, such as UE 190, that connects indirectly to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links.
- D2D device-to-device
- P2P peer-to-peer
- UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which UE 190 may indirectly obtain cellular connectivity) and a D2D P2P link 194 with WLAN STA 152 connected to the WLAN AP 150 (through which UE 190 may indirectly obtain WLAN-based Internet connectivity) .
- the D2D P2P links 192 and 194 may be supported with any well-known D2D RAT, such as LTE Direct (LTE-D) , WiFi Direct (WiFi-D) , and so on.
- FIG. 2A depicts a wireless communications system 200A showing user plane connectivity supporting dual connectivity for a UE 204 (which may correspond to any of the UEs described herein) .
- Multi-radio dual connectivity is a generalization of the intra-evolved universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA) dual connectivity, where a UE may be configured to utilize resources provided by two different nodes connected via a backhaul, one providing NR access and the other providing either E-UTRA (i.e., LTE) or NR access.
- One node acts as the master node (MN) and the other as the secondary node (SN) .
- the MN and SN are connected via a network interface and at least the MN is connected to the core network. Further, the MN and/or the SN can be operated with shared spectrum channel access.
- E-UTRA-NR dual connectivity a UE is connected to one eNB that acts as an MN and one en-gNB (anode providing NR user plane and control plane protocol terminations towards the UE) that acts as an SN.
- the eNB is connected to the EPC via the S1 interface and to the en-gNB via the X2 interface.
- the en-gNB might also be connected to the EPC via the S1-U interface and other en-gNBs via the X2-U interface.
- a UE In NG-RAN E-UTRA-NR dual connectivity (NGEN-DC) , a UE is connected to one ng-eNB that acts as an MN and one gNB that acts as an SN.
- NGEN-DC NG-RAN E-UTRA-NR dual connectivity
- a UE In NR-E-UTRA dual connectivity (NE-DC) , a UE is connected to one gNB that acts as an MN and one ng-eNB that acts as an SN.
- NR-NR dual connectivity a UE is connected to one gNB that acts as an MN and another gNB that acts as an SN.
- FIGS. 2A and 2B illustrate exemplary architectures for EN-DC.
- the disclosure is not limited to EN-DC.
- the UE 204 when configured for dual connectivity, the UE 204 may be connected to an MN 202A via a communication link 224 and to one or more SNs 202B via a communication link 228.
- the MN 202A and the SN 202B (collectively, nodes 202) may be cells or TRPs supported by different base stations and may operate according to different RATs (e.g., LTE and NR) .
- the MN 202A may correspond to a cell supported by one of macro cell base stations 102 in FIG. 1
- the SN 202B may correspond to a cell supported by mmW base station 180 in FIG. 1.
- the communication links 224 and 228 may include uplink transmissions from the UE 204 to the nodes 202 and/or downlink transmissions from the nodes 202 to the UE 204.
- the communication links 224 and 228 may use MIMO antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity, as described above with reference to FIG. 1.
- one of the carriers utilized by a base station may be a PCell for a UE and other carriers utilized by the same base station (or a difference base station operating according to the same RAT) may be SCells.
- Dual connectivity is used to achieve carrier aggregation between different base stations, and particularly, different RATs, rather than different cells supported by the same base station. Dual connectivity is well-suited in heterogeneous networks (e.g., a network of macro cells and small cells or a network of cells belonging to different RANs) .
- the UE 204 is in the PCell 222 served by the MN 202A and the SCell 226 served by the SN 202B.
- the wireless communications system 200A may further include other network nodes such as a serving gateway (SGW) 242.
- SGW serving gateway
- the SGW 242 may support a user plane interface, such as a S1-U 244A/244B with nodes 202.
- the SGW 242 may also support a control plane interface to a mobility management entity (MME) (shown in FIG. 2B) .
- MME mobility management entity
- FIG. 2B depicts a wireless communications system 200B showing control plane connectivity supporting dual connectivity for the UE 204.
- the S1-MME 248 interface between the MME 250 and the MN 202A may be used as a control plane for controlling the dual connectivity provided to UE 204.
- the control plane signaling may also include an interface (not shown) between the MME 250 and the SGW 242.
- the S1-U interface 244A connection to the SGW 242 may be terminated by the MN 202A, and the MN 202A may split some of the user plane traffic toward the SN 202B via the X2 interface 246.
- the SN 202B may be directly connected to the core network (e.g., core network 170) , while the MN 202B may not be not involved in the transport of user plane data for this type of bearer (s) over the Uu interface (i.e., the radio interface) .
- the MN 202A is responsible for radio resource control (RRC) layer (referred to as “Layer 3” ) signaling for the UE 204.
- RRC radio resource control
- both the MN 202A and the SN 202B have different physical downlink control channels (PDCCHs) and physical downlink shared channels (PDSCHs) .
- Data for the UE 204 is split at the packet data convergence protocol (PDCP) layer, but unlike carrier aggregation, the radio link control (RLC) layer and the medium access control (MAC) layer are different for the MN 202A and the SN 202B (the PDCP, RLC, and MAC layers are collectively referred to as “Layer 2” ) .
- PDCP packet data convergence protocol
- MAC medium access control
- the network may configure the amount of transmit power a UE 204 can use to transmit on each of the dual communication links 224 and 228.
- the network may configure the maximum power of the LTE (P LTE ) and NR (P NR ) communication links via RRC signaling so that the total transmitted power on the LTE and NR communication links does not exceed the power class of the EN-DC configuration when the UE 204 is transmitting on both links concurrently.
- a UE 204 may use a time-division multiplexing (TDM) pattern in order to transmit on the dual communication links 224 and 228 in turn (one at a time time) .
- the network may configure the UE 204 with the TDM pattern.
- the network may send a TDM pattern for NR and LTE transmissions to the UE 204.
- the TDM pattern may specify the length of time (e.g., in slots, subframes, milliseconds, etc.
- the TDM pattern may be selected from one of LTE’s time-division duplexing (TDD) configuration patterns, which can be different from the TDD pattern when the UE operates in LTE standalone mode.
- TDD time-division duplexing
- FIG. 3A is a block diagram illustrating generation and transport of RRC messages to a dual connectivity-capable UE 304 (which may correspond to any of the UEs described herein) .
- FIG. 3A illustrates a cellular network 300, which includes an SN 302B (which may correspond to SN 202B) , an MN 302A (which may correspond to MN 202A) , and a core network 308 (which may correspond to core network 170) .
- the cellular network 300 may be an LTE network or an NR network.
- the cellular network 300 can also have components of an LTE network and/or an NR network.
- the MN 302A may be an LTE MN
- the SN 302B may be an LTE SN.
- the UE 304 can be coupled simultaneously to the SN 302B and the MN 302A, meaning the UE 304 is configured for dual connectivity. As such, the UE 304 can generate/transmit data for/to the MN 302A and/or the SN 302B. The UE 304 can also receive/decode data from the MN 302A and/or the SN 302B. Although not shown, the UE 304 may also be coupled to more than two nodes, in which case there could be more than one SN 302B.
- FIG. 3A illustrates a control plane protocol architecture for dual connectivity including, in respective nodes or elements, instances of a NAS protocol layer 312-1, 312-2; instances of an RRC protocol layer 314-1, 314-2, 314-3, 314-4; instances of a user plane 316-1, 316-2, 316-3, 316-4; and instances of a physical layer 318-1, 318-2, 318-3, 318-4.
- a physical protocol layer (or simply “physical layer” or “PHY” ) can include, by way of example and not by limitation, a PDCCH, a physical uplink control channel (PUCCH) , a random access channel (RACH) , a PDSCH, and a physical uplink shared channel (PUSCH) , among other types of channels in the physical layer.
- control and/or user data can be received by the UE 304 via the MN 302A (e.g., as represented by the connection between the physical layer 318-1 and the physical layer 318-3) and/or via the SN 302B (e.g., as represented by the connection between the physical layer 318-2 and the physical layer 318-4) .
- MN 302A e.g., as represented by the connection between the physical layer 318-1 and the physical layer 318-3
- SN 302B e.g., as represented by the connection between the physical layer 318-2 and the physical layer 318-4 .
- Receiving data from an NR SN has different advantages compared to receiving data from an LTE MN.
- the NR SN can generate data to be transmitted at a higher frequency and/or larger bandwidth and lower latency than an LTE MN.
- Transmitting data via a higher frequency/larger bandwidth can include delivery of the data at a faster rate than transmitting data via a lower frequency.
- transmitting data via a higher frequency can include a less reliable delivery of the data as compared to transmitting data via a lower frequency.
- the UE e.g., UE 304
- the UE has a single RRC state, based on the MN RRC and a single control plane connection towards the core network.
- Each radio node has its own RRC entity 314 (e.g., an E-UTRA version if the node is an eNB or an NR version if the node is a gNB) that can generate RRC protocol data units (PDUs) to be sent to the UE 304.
- RRC PDUs generated by the SN 302B can be transported via the MN 302A to the UE 304.
- the MN 302A always sends the initial SN RRC configuration via the master cell group (MCG) signaling radio bearer (SRB) (i.e., SRB1) , but subsequent reconfigurations may be transported via the MN 302A or the SN 302B.
- MCG master cell group
- SRB radio bearer
- SRB1 uses E-UTRA PDCP. If the UE 304 supports EN-DC, regardless of whether EN-DC is configured or not, after initial connection establishment, MCG SRBs (SRB1 and SRB2) can be configured by the network to use either E-UTRA PDCP or NR PDCP (either SRB1 and SRB2 are both configured with E-UTRA PDCP, or they are both configured with NR PDCP) .
- the UE 304 can be configured to establish an SRB with the SN 302B (SRB3) to enable RRC PDUs for the SN to be sent directly between the UE 304 and the SN 302B.
- RRC PDUs for the SN 302B can only be transported directly to the UE 304 for SN RRC reconfiguration not requiring any coordination with the MN 302A.
- Measurement reporting for mobility within the SN 302B can be done directly from the UE 304 to the SN 302B if SRB3 is configured.
- Split SRB is supported for all MR-DC options, allowing duplication of RRC PDUs generated by the MN 302A, via a direct path and via the SN 302B.
- Split SRB uses NR PDCP.
- the secondary cell group (SCG) configuration is kept in the UE 304 during suspension.
- the UE 304 can be configured to release, restore, or reconfigure the SCG configuration. Otherwise, the UE 304 releases the SCG configuration (but not the radio bearer configuration) during resumption initiation.
- the UE 304 stores the PDCP/SDAP (service data adaptation protocol) configuration and the SCG configuration when moving to the RRC inactive state.
- the UE 304 can be configured to release, restore, or reconfigure the SCG configuration. Otherwise, it releases the SCG configuration.
- PDCP/SDAP service data adaptation protocol
- an RRC message originating in the MN 302A is delivered to the UE 304 directly via the MN 302A or via the SN 302B.
- An RRC message originating in the MN 302A can also be delivered to the UE 304 over a mixture of the MN 302A and the SN 302B. This can also involve duplicates of the RRC messages being sent over MN 302A and the SN 302B, for diversity.
- An RRC message originating in the SN 302B can be delivered to the UE 304 directly via the SN 302B or via the MN 302A.
- a first RRC message originating in the SN 302B can be sent to and incorporated into a second RRC message originating in the MN 302A.
- the second RRC message originating in the MN 302A can then be sent either through the user plane 316-1 and physical layer 318-1, the user plane 316-2 and the physical layer 318-2, or a mixture of both the user planes 316-1, 316-2 and the respective physical layers 318-1, 318-2.
- a NAS message originating in the core network 308 can be transferred to the RRC protocol layer 314-1 of the MN 302A.
- the core network 308 can include an MME (e.g., MME 250) in an EPC of a 3G or 4G LTE network and/or a similar entity in a 5G core network (5GC) .
- the NAS message can be incorporated into an RRC message by the instance of the RRC protocol layer 314-1.
- the RRC message generated by the instance of the RRC protocol layer 314-1 can be processed through the user plane 316-1 and/or the user plane 316-2.
- the user planes 316-1, 316-2, 316-3, 316-4 can include a PDCP layer, an RLC layer, and/or a MAC layer.
- the RRC message originating in the RRC protocol layer 314-1 of the MN 302A can be processed through the user plane 316-1 and provided directly to the UE 304 via the physical layer 318-1.
- the RRC message originating in the RRC protocol layer 314-1 can also be processed through the user plane 316-1 and the user plane 316-2, and provided (e.g., provided indirectly) via the physical layer 318-2.
- An RRC message originating in the instance of the RRC protocol layer 314-2 of the SN 302B can be processed through the user plane 316-2 and sent directly to the UE 304 via the physical layer 318-2.
- the RRC message originating in the instance of the RRC protocol layer 314-2 of the SN 302B can be processed through the user plane 316-1 of the MN 302A.
- the UE 304 can receive data through the physical layer 318-3 and/or the physical layer 318-4.
- the physical layer 318-3 and the physical layer 318-4 can correspond to the physical layer 318-1 and the physical layer 318-2, respectively.
- the UE 304 can decrypt the data received via the physical layers 318-3 and 318-4 to identify an RRC message and/or RRC messages originating from the RRC protocol layer 314-1 and/or the RRC protocol layer 314-2.
- the UE 304 can process the RRC messages through the user planes 316-3 and/or 316-4.
- the UE 304 can provide the RRC messages originating from the RRC protocol layers 314-1 and/or 314-2 to the RRC protocol layers 314-3 and 314-4 after processing the RRC messages through the user planes 316-3 and/or 316-4.
- an RRC message can be processed through the user plane 316-3 before being processed through the user plane 316-4.
- An RRC message can also be processed through all or part of the user plane 316-4 before being processed through part of the user plane 316-3.
- the RRC protocol layer 314-3 and/or the RRC protocol layer 314-4 can process the RRC messages originating from the RRC protocol layers 314-1 and/or 314-2.
- the RRC protocol layer 314-4 can generate an RRC message based on the RRC message originating from the RRC protocol layer 314-1.
- the RRC protocol layer 314-4 can also provide the generated RRC message to the RRC protocol layer 314-3.
- the RRC protocol layer 314-4 can also process and respond with RRC messages to an RRC message originating from the RRC protocol layer 314-2.
- the RRC protocol layer 314-3 can generate an RRC message based on the RRC message originating from the RRC protocol layer 314-2.
- the RRC protocol layer 314-3 can also generate an encapsulated RRC message on receipt of RRC messages from the RRC protocol layer 314-4.
- the RRC protocol layer 314-3 can also process and respond with RRC messages to an RRC message originating from the RRC protocol layer 314-1, which may include and/or encapsulate a NAS message originating from the NAS protocol layer 312-1 of the core network 308.
- the RRC protocol layer 314-3 can provide the NAS message to the NAS protocol layer 312-2 of the UE 304 for processing.
- the RRC messages from the RRCs 314-3 and 314-4 may be transferred over either of the user plane 316-4 or 316-3 or a combination of the user planes 316-4 and 316-3.
- FIG. 3B is a block diagram illustrating an example user plane architecture for dual connectivity.
- the example user plane architecture may be used, for example, for the instances of the user planes 316-1, 316-2 shown in FIG. 3A.
- FIG. 3B includes the MN 302A and the SN 302B shown in FIG. 3A.
- the example user plane architecture shown in FIG. 3B could also be used for the instances of the user planes 316-3, 316-4 of the UE 304 shown in FIG. 3A.
- each of the MN 302A and the SN 302B can include one or more user planes, and that the UE 304 can include a single user plane or more than two user planes.
- MCG bearer MCG bearer
- SCG bearer SCG bearer
- split bearer MCG bearer
- E-UTRA connected to EPC dual connectivity if the UE 304 supports EN-DC, regardless of whether EN-DC is configured or not, the network can configure either E-UTRA PDCP or NR PDCP for MN-terminated MCG bearers, while NR PDCP is used for all other bearers.
- E-UTRA PDCP In MR-DC with 5GC, NR PDCP is used for all bearer types.
- E-UTRA RLC/MAC is used in the MN 302A while NR RLC/MAC is used in the SN 302B.
- NR RLC/MAC is used in the MN 302A, while E-UTRA RLC/MAC is used in the SN 302B.
- NR RLC/MAC is used in both the MN 302A and the SN 302B.
- each bearer (MCG, SCG, and split bearer) can be terminated either in the MN 302A or in the SN 302B.
- MCG MCG
- SCG SCG
- split bearer each bearer can be terminated either in the MN 302A or in the SN 302B.
- MCG MCG
- SCG SCG
- split bearer the logical channels are always configured at least in the MCG (i.e. this is still an MR-DC configuration and a PCell always exists) .
- MCG Mobility Management Entity
- the MN 302A shown in FIG. 3B includes a user plane comprising a PDCP layer 323-1, an RLC layer 325-1, and a MAC layer 327-1.
- the MN 302A can also include a user plane comprising a PDCP layer 323-2, an RLC layer 325-2, and a MAC protocol layer 327-1.
- a master cell group (MCG) bearer 329-1 can use the PDCP protocol layer 323-1, the RLC protocol layer 325-1, and the MAC protocol layer 327-1.
- the MCG bearer 329-1 can carry traffic received for a bearer or quality of service (QoS) flow over the S1 interface.
- QoS quality of service
- a split bearer 329-2 can use the PDCP layer 323-2, the RLC layer 325-2, and the MAC layer 327-1.
- the split bearer 329-2 can use a PDCP layer 323-2, an RLC layer 325-3, and a MAC layer 327-2.
- a split bearer can also use a combination of the PDCP layer 323-2 with RLC layer 325-2, the MAC layer 327-1 and an RLC layer 325-3, and a MAC layer 327-2.
- the split bearer 329-2 can be implemented using the X2 or similar interfaces.
- a split bearer can receive traffic over an S1 interface or RRC messages as discussed above.
- the SN 302B includes a user plane comprising a PDCP layer 323-3, an RLC layer 325-4, and the MAC layer 327-2.
- An SCG bearer 329-3 can use the PDCP protocol layer 323-3, the RLC protocol layer 325-4, and the MAC protocol layer 327-2.
- the SCG bearer 329-3 can carry traffic received over the S1 interface or RRC messages originating in an SN 302B.
- MR-DC Magnetic resonance Imaging
- FIGS. 4A, 4B, and 4C illustrate several exemplary components (represented by corresponding blocks) that may be incorporated into a UE 402 (which may correspond to any of the UEs described herein) , a base station 404 (which may correspond to any of the base stations described herein) , and a network entity 406 (which may correspond to or embody any of the network functions described herein) to support the file transmission operations as taught herein.
- a UE 402 which may correspond to any of the UEs described herein
- a base station 404 which may correspond to any of the base stations described herein
- a network entity 406 which may correspond to or embody any of the network functions described herein
- apparatuses in a system may include components similar to those described to provide similar functionality.
- a given apparatus may contain one or more of the components.
- an apparatus may include multiple transceiver components that enable the apparatus to operate on multiple carriers and/or communicate via different technologies.
- the UE 402 and the base station 404 each include wireless wide area network (WWAN) transceiver 410 and 450, respectively, configured to communicate via one or more wireless communication networks (not shown) , such as an NR network, an LTE network, a GSM network, and/or the like.
- the WWAN transceivers 410 and 450 may be connected to one or more antennas 416 and 456, respectively, for communicating with other network nodes, such as other UEs, access points, base stations (e.g., ng-eNBs, gNBs) , etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc.
- RAT e.g., NR, LTE, GSM, etc.
- the WWAN transceivers 410 and 450 may be variously configured for transmitting and encoding signals 418 and 458 (e.g., messages, indications, information, and so on) , respectively, and, conversely, for receiving and decoding signals 418 and 458 (e.g., messages, indications, information, pilots, and so on) , respectively, in accordance with the designated RAT.
- signals 418 and 458 e.g., messages, indications, information, and so on
- decoding signals 418 and 458 e.g., messages, indications, information, pilots, and so on
- the transceivers 410 and 450 include one or more transmitters 414 and 454, respectively, for transmitting and encoding signals 418 and 458, respectively, and one or more receivers 412 and 452, respectively, for receiving and decoding signals 418 and 458, respectively.
- the UE 402 and the base station 404 also include, at least in some cases, wireless local area network (WLAN) transceivers 420 and 460, respectively.
- WLAN transceivers 420 and 460 may be connected to one or more antennas 426 and 466, respectively, for communicating with other network nodes, such as other UEs, access points, base stations, etc., via at least one designated RAT (e.g., WiFi, LTE-D, etc. ) over a wireless communication medium of interest.
- RAT e.g., WiFi, LTE-D, etc.
- the WLAN transceivers 420 and 460 may be variously configured for transmitting and encoding signals 428 and 468 (e.g., messages, indications, information, and so on) , respectively, and, conversely, for receiving and decoding signals 428 and 468 (e.g., messages, indications, information, pilots, and so on) , respectively, in accordance with the designated RAT.
- the transceivers 420 and 460 include one or more transmitters 424 and 464, respectively, for transmitting and encoding signals 428 and 468, respectively, and one or more receivers 422 and 462, respectively, for receiving and decoding signals 428 and 468, respectively.
- Transceiver circuitry including at least one transmitter and at least one receiver may comprise an integrated device (e.g., embodied as a transmitter circuit and a receiver circuit of a single communication device) in some implementations, may comprise a separate transmitter device and a separate receiver device in some implementations, or may be embodied in other ways in other implementations.
- a transmitter may include or be coupled to a plurality of antennas (e.g., antennas 416, 426, 456, 466) , such as an antenna array, that permits the respective apparatus to perform transmit “beamforming, ” as described herein.
- a receiver may include or be coupled to a plurality of antennas (e.g., antennas 416, 426, 456, 466) , such as an antenna array, that permits the respective apparatus to perform receive beamforming, as described herein.
- the transmitter and receiver may share the same plurality of antennas (e.g., antennas 416, 426, 456, 466) , such that the respective apparatus can only receive or transmit at a given time, not both at the same time.
- a wireless communication device e.g., one or both of the transceivers 410 and 420 and/or 450 and 460) of the UE 402 and/or the base station 404 may also comprise a network listen module (NLM) or the like for performing various measurements.
- NLM network listen module
- the WWAN transceiver 410 may comprise at least two WWAN transceivers, one configured to operate in accordance with a first RAT (e.g., LTE) and one configured to operate in accordance with a second RAT (e.g., NR) .
- the UE 402 may include a single WWAN transceiver 410 that includes at least two receivers 412 and at least two transmitters 414, a first pair of a receiver and transmitter configured to operate in accordance with a first RAT (e.g., LTE) and a second pair of a receiver and transmitter configured to operate in accordance with a second RAT (e.g., NR) .
- a first RAT e.g., LTE
- a second RAT e.g., NR
- the WWAN transceiver 410 may have a single receiver 412 and a single transmitter 414 that are configured to operate in accordance with both a first RAT (e.g., LTE) and a second RAT (e.g., NR) using, for example, TDM.
- a first RAT e.g., LTE
- a second RAT e.g., NR
- the UE 402 and the base station 404 may also include, at least in some cases, satellite positioning systems (SPS) receivers 430 and 470.
- the SPS receivers 430 and 470 may be connected to one or more antennas 436 and 476, respectively, for receiving SPS signals 438 and 478, respectively, such as global positioning system (GPS) signals, global navigation satellite system (GLONASS) signals, Galileo signals, Beidou signals, Indian Regional Navigation Satellite System (NAVIC) , Quasi-Zenith Satellite System (QZSS) , etc.
- the SPS receivers 430 and 470 may comprise any suitable hardware and/or software for receiving and processing SPS signals 438 and 478, respectively.
- the SPS receivers 430 and 470 request information and operations as appropriate from the other systems, and performs calculations necessary to determine positions of the UE 402 and the base station 404 using measurements obtained by any suitable SPS algorithm.
- the base station 404 and the network entity 406 each include at least one network interfaces 480 and 490 for communicating with other network entities.
- the network interfaces 480 and 490 e.g., one or more network access ports
- the network interfaces 480 and 490 may be implemented as transceivers configured to support wire-based or wireless signal communication. This communication may involve, for example, sending and receiving messages, parameters, and/or other types of information.
- the UE 402, the base station 404, and the network entity 406 also include other components that may be used in conjunction with the operations as disclosed herein.
- the UE 402 includes processor circuitry implementing a processing system 432 for providing functionality relating to, for example, positioning operations, and for providing other processing functionality.
- the base station 404 includes a processing system 484 for providing functionality relating to, for example, positioning operations as disclosed herein, and for providing other processing functionality.
- the network entity 406 includes a processing system 494 for providing functionality relating to, for example, positioning operations as disclosed herein, and for providing other processing functionality.
- processing systems 432, 484, and 494 may include, for example, one or more general purpose processors, multi-core processors, ASICs, digital signal processors (DSPs) , field programmable gate arrays (FPGA) , or other programmable logic devices or processing circuitry.
- general purpose processors multi-core processors
- ASICs application-specific integrated circuits
- DSPs digital signal processors
- FPGA field programmable gate arrays
- FPGA field programmable gate arrays
- the UE 402, the base station 404, and the network entity 406 include memory circuitry implementing memory components 440, 486, and 496 (e.g., each including a memory device) , respectively, for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, and so on) .
- the UE 402, the base station 404, and the network entity 406 may include cell selection components 442, 488, and 498, respectively.
- the cell selection components 442, 488, and 498 may be hardware circuits that are part of or coupled to the processing systems 432, 484, and 494, respectively, that, when executed, cause the UE 402, the base station 404, and the network entity 406 to perform the functionality described herein.
- the cell selection components 442, 488, and 498 may be external to the processing systems 432, 484, and 494 (e.g., part of a modem processing system, integrated with another processing system, etc. ) .
- the cell selection components 442, 488, and 498 may be memory modules (as shown in FIGS. 4A-C) stored in the memory components 440, 486, and 496, respectively, that, when executed by the processing systems 432, 484, and 494 (or a modem processing system, another processing system, etc. ) , cause the UE 402, the base station 404, and the network entity 406 to perform the functionality described herein.
- the UE 402 may include one or more sensors 444 coupled to the processing system 432 to provide movement and/or orientation information that is independent of motion data derived from signals received by the WWAN transceiver 410, the WLAN transceiver 420, and/or the SPS receiver 430.
- the sensor (s) 444 may include an accelerometer (e.g., a micro-electrical mechanical systems (MEMS) device) , a gyroscope, a geomagnetic sensor (e.g., a compass) , an altimeter (e.g., a barometric pressure altimeter) , and/or any other type of movement detection sensor.
- MEMS micro-electrical mechanical systems
- the senor (s) 444 may include a plurality of different types of devices and combine their outputs in order to provide motion information.
- the sensor (s) 444 may use a combination of a multi-axis accelerometer and orientation sensors to provide the ability to compute positions in 2D and/or 3D coordinate systems.
- the UE 402 includes a user interface 446 for providing indications (e.g., audible and/or visual indications) to a user and/or for receiving user input (e.g., upon user actuation of a sensing device such a keypad, a touch screen, a microphone, and so on) .
- a user interface 446 for providing indications (e.g., audible and/or visual indications) to a user and/or for receiving user input (e.g., upon user actuation of a sensing device such a keypad, a touch screen, a microphone, and so on) .
- the base station 404 and the network entity 406 may also include user interfaces.
- IP packets from the network entity 406 may be provided to the processing system 484.
- the processing system 484 may implement functionality for an RRC layer, a PDCP layer, an RLC layer, and a MAC layer.
- the processing system 484 may provide RRC layer functionality associated with broadcasting of system information (e.g., master information block (MIB) , system information blocks (SIBs) ) , RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release) , inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification) , and handover support functions; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through automatic repeat request (ARQ) , concatenation, segmentation, and reassembly of RLC service data units (SDUs) , re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.
- the transmitter 454 and the receiver 452 may implement Layer-1 functionality associated with various signal processing functions.
- Layer-1 which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing.
- the transmitter 454 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK) , quadrature phase-shift keying (QPSK) , M-phase-shift keying (M-PSK) , M-quadrature amplitude modulation (M-QAM) ) .
- BPSK binary phase-shift keying
- QPSK quadrature phase-shift keying
- M-PSK M-phase-shift keying
- M-QAM M-quadrature amplitude modulation
- Each stream may then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream.
- OFDM symbol stream is spatially precoded to produce multiple spatial streams.
- Channel estimates from a channel estimator may be used to determine the coding and modulation scheme, as well as for spatial processing.
- the channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 402.
- Each spatial stream may then be provided to one or more different antennas 456.
- the transmitter 454 may modulate an RF carrier with a respective spatial stream for transmission.
- the receiver 412 receives a signal through its respective antenna (s) 416.
- the receiver 412 recovers information modulated onto an RF carrier and provides the information to the processing system 432.
- the transmitter 414 and the receiver 412 implement Layer-1 functionality associated with various signal processing functions.
- the receiver 412 may perform spatial processing on the information to recover any spatial streams destined for the UE 402. If multiple spatial streams are destined for the UE 402, they may be combined by the receiver 412 into a single OFDM symbol stream.
- the receiver 412 then converts the OFDM symbol stream from the time-domain to the frequency domain using a fast Fourier transform (FFT) .
- the frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal.
- FFT fast Fourier transform
- the symbols on each subcarrier, and the reference signal are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 404. These soft decisions may be based on channel estimates computed by a channel estimator. The soft decisions are then decoded and de-interleaved to recover the data and control signals that were originally transmitted by the base station 404 on the physical channel. The data and control signals are then provided to the processing system 432, which implements Layer-3 and Layer-2 functionality.
- the processing system 432 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network.
- the processing system 432 is also responsible for error detection.
- the processing system 432 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs) , demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ) , priority handling, and logical channel prioritization.
- RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting
- Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station 404 may be used by the transmitter 414 to select the appropriate coding and modulation schemes, and to facilitate spatial processing.
- the spatial streams generated by the transmitter 414 may be provided to different antenna (s) 416.
- the transmitter 414 may modulate an RF carrier with a respective spatial stream for transmission.
- the uplink transmission is processed at the base station 404 in a manner similar to that described in connection with the receiver function at the UE 402.
- the receiver 452 receives a signal through its respective antenna (s) 456.
- the receiver 452 recovers information modulated onto an RF carrier and provides the information to the processing system 484.
- the processing system 484 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 402. IP packets from the processing system 484 may be provided to the core network.
- the processing system 484 is also responsible for error detection.
- the UE 402 the base station 404, and/or the network entity 406 are shown in FIGS. 4A-C as including various components that may be configured according to the various examples described herein. It will be appreciated, however, that the illustrated blocks may have different functionality in different designs.
- the various components of the UE 402, the base station 404, and the network entity 406 may communicate with each other over data buses 434, 482, and 492, respectively.
- the components of FIGS. 4A-C may be implemented in various ways.
- the components of FIGS. 4A-C may be implemented in one or more circuits such as, for example, one or more processors and/or one or more ASICs (which may include one or more processors) .
- each circuit may use and/or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality.
- some or all of the functionality represented by blocks 410 to 446 may be implemented by processor and memory component (s) of the UE 402 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components) .
- some or all of the functionality represented by blocks 450 to 488 may be implemented by processor and memory component (s) of the base station 404 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components) .
- some or all of the functionality represented by blocks 490 to 498 may be implemented by processor and memory component (s) of the network entity 406 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components) .
- An NR network may operate as either a standalone (SA) network or a non-standalone (NSA) network.
- An NR SA network is designed to provide NR connectivity without having to utilize existing network architecture (e.g., a legacy LTE network) , and includes a 5GC.
- legacy carriers e.g., LTE, 3G, GSM, etc.
- LTE Long Term Evolution
- 3G Third Generation
- GSM Global System for Mobile communications
- an LTE network can also operate in either SA or NSA mode.
- a UE connects to an LTE eNB as the master node (e.g., MN 202A, MN 302A) for mobility management and coverage, and one or more additional NR gNBs as secondary nodes (e.g., SN 202B, SN 302B) for enhanced coverage and/or throughput, as in the examples of FIGS. 2A and 2B.
- LTE eNB as the master node
- additional NR gNBs as secondary nodes
- SN 202B, SN 302B secondary nodes
- DCNR refers to any type of NSA NR dual connectivity where the MN is an LTE cell and the SN is an NR cell, such as EN-DC and NGEN-DC.
- the UE is being informed that the LTE cell to which it has attached as the MN does not support dual connectivity with an NR SN.
- This type of situation can occur due to the NR deployment not covering the entirety of the geographic region in which the UE is located. Since it may be some time before there is full NR coverage in the region, there needs to be a solution for customers in the area to more reliably gain NR access.
- the present disclosure provides techniques for quickly selecting a DCNR-capable LTE cell as the MN for NSA NR dual connectivity.
- the UE when a UE receives a “restrict DCNR” message from the network for a particular LTE cell, the UE can record the cell ID (e.g., PCI, VCI, CGI) and lower its priority for subsequent cell registrations and reselections.
- the UE may store the cell ID in a list of other such cell IDs (referred to herein as the “RestrictDCNR_Cell_List” ) .
- the UE can then trigger cell reselection until it attaches to an LTE cell with DCNR capability (or until it has performed some number of cell reselection attempts) .
- the UE Upon attaching to an LTE cell that supports DCNR, the UE is then provided NSA NR service.
- FIG. 5 illustrates an exemplary method 500 for selecting a DCNR-capable LTE cell as the MN for NSA NR dual connectivity, according to aspects of the disclosure.
- a UE 504 is attempting to attach to an LTE cell that will be an MN for an NSA NR dual connectivity session.
- the method 500 may be performed between the UE 504 (e.g., any of the UEs described herein) and a first LTE cell 502A (labelled “LTE Cell_1” ) and a second LTE cell 502B (labelled “LTE Cell_2” ) .
- the LTE cells 502 may be LTE cells supported by any two of the base stations described herein.
- the operations performed by the UE 504 are more specifically performed by the modem of the UE 504, which may include one or more transceivers (e.g., WWAN transceiver 410) and/or two or more pairs of receivers and transmitters (e.g., one or more pairs of receiver 412 and transmitter 414) .
- the modem of the UE 504 may include one or more transceivers (e.g., WWAN transceiver 410) and/or two or more pairs of receivers and transmitters (e.g., one or more pairs of receiver 412 and transmitter 414) .
- the UE 504 sends an attachment request ( “ATTACH REQUEST” ) to the first LTE cell 502A.
- the attachment request includes an indication that the UE 504 is attempting to establish a connection with an LTE cell that supports DCNR (as indicated by the field “DCNR support” ) .
- the first LTE cell 502A responds to the attachment request with an attachment acceptance message ( “ATTACH ACCEPT” ) .
- the attachment acceptance message includes an indication that the first LTE cell 502A does not support NSA NR dual connectivity (as indicated by the field “restrict DCNR” ) .
- the UE 504 adds the cell ID (e.g., PCI, VCI, CGI) of the first LTE cell 502A to a list of LTE cells that do not support NSA NR dual connectivity (referred to as the “RestrictDCNR_Cell_List” ) .
- the UE 504 may store the list in local memory (e.g., memory component 440) .
- the UE 504 decides to reselect to a different LTE cell, i.e., the second LTE cell 502B.
- the UE 504 may identify the second LTE cell 502B based on a cell search performed by the UE 504 before the method 500 (e.g., when the UE 504 entered the geographic region containing LTE cells 502A and 502B) .
- the signal strength of the signals received from the second LTE cell 502B should be high enough to support reliable (at least within a QoS threshold) wireless communication between the UE 504 and the second LTE cell 502B.
- the second LTE cell 502B may not have been the UE’s 504 first choice for network access, it is an acceptable second choice for network access.
- the UE 504 may send an attachment request ( “ATTACH REQUEST” ) to the second LTE cell 502B.
- the attachment request includes an indication that the UE 504 is attempting to establish a connection with an LTE cell that supports DCNR (as indicated by the field “DCNR support” ) .
- the UE 504 may send a tracking area update request ( “TRACKING_AREA_UPDATE_REQ” ) to the second LTE cell 502B.
- the tracking area update request includes an indication that the UE 504 is attempting to establish a connection with an LTE cell that supports DCNR (as indicated by the field “DCNR support” ) .
- the UE 504 may send a tracking area update request instead of an attachment request if the UE 504 is already attached to the network via another cell. More specifically, if the UE 504 attaches to the network via the first LTE cell 502A at 512, the UE 504 may send a tracking area update request at 518. However, if the UE 504 drops, or does not establish, the connection to the network via the first LTE cell 502A (e.g., because it cannot maintain that connection while attaching to the second LTE cell 502B) , then the UE 504 may send an attachment request at 518.
- a tracking area is a geographical combination of several base stations (e.g., eNBs in LTE) .
- a UE e.g., UE 504 triggers a tracking area update after the UE completes an attachment procedure and moves into a mobility management registered state.
- a tracking area update indicates to the network that the UE 504 has moved from one cell (e.g., first LTE cell 502A) to another cell (e.g., second LTE cell 502B) .
- the second LTE cell 502B responds to the attachment request with an attachment acceptance message ( “ATTACH ACCEPT” ) .
- the attachment acceptance message includes an indication that the second LTE cell 502B supports NSA NR dual connectivity (as indicated by the field “DCNR_support” ) .
- the second LTE cell 502B responds to the tracking area update request with a tracking area update acceptance ( “TRACKING_AREA_UPDATE_ACCEPT” ) .
- the tracking area update acceptance includes an indication that the second LTE cell 502B supports NSA NR dual connectivity (as indicated by the field “DCNR_support” ) .
- the UE 504 is attached to the second LTE cell 502B as an MN, and can then be configured by the network for NSA NR dual connectivity with one or more SNs (not shown) .
- FIG. 5 illustrates only two LTE cells, as will be appreciated, the method 500 may be performed with any number of LTE cells until the UE 504 successfully connects to an LTE cell that supports DCNR. Alternatively, the method 500 may end after some number of attempts to connect to an LTE cell that supports DCNR have failed. Upon such a failure, the UE 504 may simply (re) connect to the best available LTE cell.
- the UE 504 may eventually disconnect from the second LTE cell 502B and move to another geographic region, where it can repeat method 500 with other LTE cells.
- the UE 504 Upon returning to the geographic region containing LTE cells 502A and 502B, and discovering LTE cells 502A and 502B after performing a cell search in that region, the UE 504 consults the RestrictDCNR_Cell_List. Based on the cell ID of the first LTE cell 502A being stored in the RestrictDCNR_Cell_List, the UE 504 selects the second LTE cell 502B to attach to the network, even though the first LTE cell 502A may have otherwise been the higher priority, or more preferred, cell (e.g., due to higher signal strength) .
- the UE 504 may order the cells according to the priority of connecting to each cell. For example, the UE 504 may order the discovered cells by their respective signal strengths, with cells having higher signal strengths having a higher priority. The UE 504 then checks the RestrictDCNR_Cell_List for the discovered cells, starting with the highest priority cell. If a discovered cell appears on the RestrictDCNR_Cell_List, the UE 504 does not connect to it and checks whether or not the next discovered cell is on the RestrictDCNR_Cell_List. When the UE 504 determines that a discovered cell is not on the RestrictDCNR_Cell_List, the UE 504 connects to that cell. Thus, by maintaining the RestrictDCNR_Cell_List, the UE 504 can more quickly connect to an LTE cell that supports NSA NR dual connectivity.
- the UE 504 may remove a cell ID from the RestrictDCNR_Cell_List after it has been on the list for some threshold period of time (e.g., days, months) . This allows for the possibility of network updates, such as an LTE cell that did not support DCNR when the UE 504 first attempted to connect to it later being upgraded to support DCNR.
- some threshold period of time e.g., days, months
- the network may provide the RestrictDCNR_Cell_List to the UE 504, rather than the UE 504 generating it over time.
- the UE 504 may receive the list from a network entity, such as the application server 172, SGW 242, MME 250, or other component of the core network 170.
- FIG. 6 illustrates an exemplary method 600 of wireless communication, according to aspects of the disclosure.
- the method 600 may be performed by any of the UEs described herein.
- the UE discovers a first cell (e.g., LTE cell 502A) operating in accordance with a first RAT (e.g., LTE) .
- the UE may discover the first cell during a cell search procedure.
- the UE may or may not camp on the first cell.
- operation 610 may be performed by WWAN transceiver 410, processing system 432, memory component 440, and/or cell selection component 442, any or all of which may be considered means for performing this operation.
- the UE determines that the first cell does not support NSA access for a second RAT (e.g., NR) , as at, for example, 512 of FIG. 5.
- a second RAT e.g., NR
- operation 620 may be performed by WWAN transceiver 410, processing system 432, memory component 440, and/or cell selection component 442, any or all of which may be considered means for performing this operation.
- the UE in response to determining that the first cell does not support NSA access for the second RAT at 620, the UE connects to a second cell (e.g., LTE cell 502B) operating in accordance with the first RAT, as at, for example, 518 and 520 of FIG. 5.
- the second cell supports NSA access for the second RAT (e.g., EN-DC and NGEN-DC) .
- operation 630 may be performed by WWAN transceiver 410, processing system 432, memory component 440, and/or cell selection component 442, any or all of which may be considered means for performing this operation.
- a general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine.
- a processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
- a software module may reside in random access memory (RAM) , flash memory, read-only memory (ROM) , erasable programmable ROM (EPROM) , electrically erasable programmable ROM (EEPROM) , registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
- An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium.
- the storage medium may be integral to the processor.
- the processor and the storage medium may reside in an ASIC.
- the ASIC may reside in a user terminal (e.g., UE) .
- the processor and the storage medium may reside as discrete components in a user terminal.
- the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium.
- Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another.
- a storage media may be any available media that can be accessed by a computer.
- such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.
- any connection is properly termed a computer-readable medium.
- the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave
- the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.
- Disk and disc includes compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Disclosed are techniques for wireless communication, In an aspect, a user equipment (UE) discovers a first cell operating in accordance with a first radio access technology (RAT), determines that the first cell does not support non-standalone (NS A) access for a second RAT, and in response to determining that the first cell does not support NSA access for the second RAT, connecting to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
Description
BACKGROUND OF THE DISCLOSURE
1. Field of the Disclosure
Aspects of the disclosure relate generally to wireless communications.
2. Description of the Related Art
Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G) , a second-generation (2G) digital wireless phone service (including interim 2.5G networks) , a third-generation (3G) high speed data, Internet-capable wireless service and a fourth-generation (4G) service (e.g., LTE or WiMax) . There are presently many different types of wireless communication systems in use, including cellular and personal communications service (PCS) systems. Examples of known cellular systems include the cellular Analog Advanced Mobile Phone System (AMPS) , and digital cellular systems based on code division multiple access (CDMA) , frequency division multiple access (FDMA) , time division multiple access (TDMA) , the Global System for Mobile communication (GSM) , etc.
A fifth generation (5G) wireless standard, also referred to as New Radio (NR) , enables higher data transfer speeds, greater numbers of connections, and better coverage, among other improvements. The 5G standard, according to the Next Generation Mobile Networks Alliance, is designed to provide data rates of several tens of megabits per second to each of tens of thousands of users, with 1 gigabit per second to tens of workers on an office floor. Several hundreds of thousands of simultaneous connections should be supported in order to support large wireless deployments. Consequently, the spectral efficiency of 5G mobile communications should be significantly enhanced compared to the current 4G standard. Furthermore, signaling efficiencies should be enhanced and latency should be substantially reduced compared to current standards.
SUMMARY
The following presents a simplified summary relating to one or more aspects disclosed herein. Thus, the following summary should not be considered an extensive overview relating to all contemplated aspects, nor should the following summary be considered to identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below.
In an aspect, a method of wireless communication performed by a user equipment (UE) includes discovering a first cell operating in accordance with a first radio access technology (RAT) , determining that the first cell does not support non-standalone (NSA) access for a second RAT, and in response to determining that the first cell does not support NSA access for the second RAT, connecting to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
In an aspect, a UE includes a memory, at least one transceiver, and at least one processor communicatively coupled the memory and the at least one transceiver, the at least one processor configured to: discover a first cell operating in accordance with a first RAT, determine that the first cell does not support NSA access for a second RAT, and connect, in response to a determination that the first cell does not support NSA access for the second RAT, to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
In an aspect, a UE includes means for discovering a first cell operating in accordance with a first RAT, means for determining that the first cell does not support NSA access for a second RAT, and means for connecting, in response to determining that the first cell does not support NSA access for the second RAT, to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
In an aspect, a non-transitory computer-readable medium storing computer-executable instructions includes computer-executable instructions comprising: at least one instruction instructing a UE to discover a first cell operating in accordance with a first RAT, at least one instruction instructing the UE to determine that the first cell does not support NSA access for a second RAT, and at least one instruction instructing the UE to connect, in response to determining that the first cell does not support NSA access for the second RAT, to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
Other objects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description.
The accompanying drawings are presented to aid in the description of various aspects of the disclosure and are provided solely for illustration of the aspects and not limitation thereof.
FIG. 1 illustrates an exemplary wireless communications system, according to aspects of the disclosure.
FIG. 2A depicts a wireless communications system showing user plane connectivity supporting dual connectivity for a UE.
FIG. 2B depicts a wireless communications system showing control plane connectivity supporting dual connectivity for the UE.
FIG. 3A illustrates a control plane protocol architecture for dual connectivity.
FIG. 3B is a block diagram illustrating an example user plane architecture for dual connectivity.
FIGS. 4A to 4C are simplified block diagrams of several sample aspects of components that may be employed in a UE, a base station, and a network entity, respectively.
FIG. 5 illustrates an exemplary method for selecting a cell capable of non-standalone dual connectivity, according to aspects of the disclosure.
FIG. 6 illustrates an exemplary method of wireless communication, according to aspects of the disclosure.
Aspects of the disclosure are provided in the following description and related drawings directed to various examples provided for illustration purposes. Alternate aspects may be devised without departing from the scope of the disclosure. Additionally, well-known elements of the disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the disclosure.
The words “exemplary” and/or “example” are used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” and/or “example” is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term “aspects of the disclosure” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation.
Those of skill in the art will appreciate that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description below may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular application, in part on the desired design, in part on the corresponding technology, etc.
Further, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be recognized that various actions described herein can be performed by specific circuits (e.g., application specific integrated circuits (ASICs) ) , by program instructions being executed by one or more processors, or by a combination of both. Additionally, the sequence (s) of actions described herein can be considered to be embodied entirely within any form of non-transitory computer-readable storage medium having stored therein a corresponding set of computer instructions that, upon execution, would cause or instruct an associated processor of a device to perform the functionality described herein. Thus, the various aspects of the disclosure may be embodied in a number of different forms, all of which have been contemplated to be within the scope of the claimed subject matter. In addition, for each of the aspects described herein, the corresponding form of any such aspects may be described herein as, for example, “logic configured to” perform the described action.
As used herein, the terms “user equipment” (UE) and “base station” are not intended to be specific or otherwise limited to any particular radio access technology (RAT) , unless otherwise noted. In general, a UE may be any wireless communication device (e.g., a mobile phone, router, tablet computer, laptop computer, tracking device, wearable (e.g., smartwatch, glasses, augmented reality (AR) /virtual reality (VR) headset, etc. ) , vehicle (e.g., automobile, motorcycle, bicycle, etc. ) , Internet of Things (IoT) device, etc. ) used by a user to communicate over a wireless communications network. A UE may be mobile or may (e.g., at certain times) be stationary, and may communicate with a radio access network (RAN) . As used herein, the term “UE” may be referred to interchangeably as an “access terminal” or “AT, ” a “client device, ” a “wireless device, ” a “subscriber device, ” a “subscriber terminal, ” a “subscriber station, ” a “user terminal” or UT, a “mobile device, ” a “mobile terminal, ” a “mobile station, ” or variations thereof. Generally, UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected with external networks such as the Internet and with other UEs. Of course, other mechanisms of connecting to the core network and/or the Internet are also possible for the UEs, such as over wired access networks, wireless local area network (WLAN) networks (e.g., based on IEEE 802.11, etc. ) and so on.
A base station may operate according to one of several RATs in communication with UEs depending on the network in which it is deployed, and may be alternatively referred to as an access point (AP) , a network node, a NodeB, an evolved NodeB (eNB) , a next generation eNB (ng-eNB) , a New Radio (NR) Node B (also referred to as a gNB or gNodeB) , etc. A base station may be used primarily to support wireless access by UEs, including supporting data, voice, and/or signaling connections for the supported UEs. In some systems a base station may provide purely edge node signaling functions while in other systems it may provide additional control and/or network management functions. A communication link through which UEs can send signals to a base station is called an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc. ) . A communication link through which the base station can send signals to UEs is called a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc. ) . As used herein the term traffic channel (TCH) can refer to either an uplink /reverse or downlink /forward traffic channel.
The term “base station” may refer to a single physical transmission-reception point (TRP) or to multiple physical TRPs that may or may not be co-located. For example, where the term “base station” refers to a single physical TRP, the physical TRP may be an antenna of the base station corresponding to a cell (or several cell sectors) of the base station. Where the term “base station” refers to multiple co-located physical TRPs, the physical TRPs may be an array of antennas (e.g., as in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming) of the base station. Where the term “base station” refers to multiple non-co-located physical TRPs, the physical TRPs may be a distributed antenna system (DAS) (anetwork of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (aremote base station connected to a serving base station) . Alternatively, the non-co-located physical TRPs may be the serving base station receiving the measurement report from the UE and a neighbor base station whose reference RF signals (or simply “reference signals” ) the UE is measuring. Because a TRP is the point from which a base station transmits and receives wireless signals, as used herein, references to transmission from or reception at a base station are to be understood as referring to a particular TRP of the base station.
In some implementations that support positioning of UEs, a base station may not support wireless access by UEs (e.g., may not support data, voice, and/or signaling connections for UEs) , but may instead transmit reference signals to UEs to be measured by the UEs, and/or may receive and measure signals transmitted by the UEs. Such a base station may be referred to as a positioning beacon (e.g., when transmitting signals to UEs) and/or as a location measurement unit (e.g., when receiving and measuring signals from UEs) .
An “RF signal” comprises an electromagnetic wave of a given frequency that transports information through the space between a transmitter and a receiver. As used herein, a transmitter may transmit a single “RF signal” or multiple “RF signals” to a receiver. However, the receiver may receive multiple “RF signals” corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through multipath channels. The same transmitted RF signal on different paths between the transmitter and receiver may be referred to as a “multipath” RF signal. As used herein, an RF signal may also be referred to as a “wireless signal” or simply a “signal” where it is clear from the context that the term “signal” refers to a wireless signal or an RF signal.
According to various aspects, FIG. 1 illustrates an exemplary wireless communications system 100. The wireless communications system 100 (which may also be referred to as a wireless wide area network (WWAN) ) may include various base stations 102 and various UEs 104. The base stations 102 may include macro cell base stations (high power cellular base stations) and/or small cell base stations (low power cellular base stations) . In an aspect, the macro cell base station may include eNBs and/or ng-eNBs where the wireless communications system 100 corresponds to an LTE network, or gNBs where the wireless communications system 100 corresponds to a NR network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc.
The base stations 102 may collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC) ) through backhaul links 122, and through the core network 170 to one or more application servers 172 (which may be part of core network 170 or may be external to core network 170) . In addition to other functions, the base stations 102 may perform functions that relate to one or more of transferring user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC /5GC) over backhaul links 134, which may be wired or wireless.
The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. In an aspect, one or more cells may be supported by a base station 102 in each coverage area 110. A “cell” is a logical communication entity used for communication with a base station (e.g., over some frequency resource, referred to as a carrier frequency, component carrier, carrier, band, or the like) , and may be associated with an identifier (e.g., a physical cell identifier (PCI) , a virtual cell identifier (VCI) , a cell global identifier (CGI) ) for distinguishing cells operating via the same or a different carrier frequency. In some cases, different cells may be configured according to different protocol types (e.g., machine-type communication (MTC) , narrowband IoT (NB-IoT) , enhanced mobile broadband (eMBB) , or others) that may provide access for different types of UEs. Because a cell is supported by a specific base station, the term “cell” may refer to either or both of the logical communication entity and the base station that supports it, depending on the context. In addition, because a TRP is typically the physical transmission point of a cell, the terms “cell” and “TRP” may be used interchangeably. In some cases, the term “cell” may also refer to a geographic coverage area of a base station (e.g., a sector) , insofar as a carrier frequency can be detected and used for communication within some portion of geographic coverage areas 110.
While neighboring macro cell base station 102 geographic coverage areas 110 may partially overlap (e.g., in a handover region) , some of the geographic coverage areas 110 may be substantially overlapped by a larger geographic coverage area 110. For example, a small cell base station 102'may have a coverage area 110'that substantially overlaps with the coverage area 110 of one or more macro cell base stations 102. A network that includes both small cell and macro cell base stations may be known as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) .
The communication links 120 between the base stations 102 and the UEs 104 may include uplink (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use MIMO antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links 120 may be through one or more carrier frequencies. Allocation of carriers may be asymmetric with respect to downlink and uplink (e.g., more or less carriers may be allocated for downlink than for uplink) .
The wireless communications system 100 may further include a wireless local area network (WLAN) access point (AP) 150 in communication with WLAN stations (STAs) 152 via communication links 154 in an unlicensed frequency spectrum (e.g., 5 GHz) . When communicating in an unlicensed frequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may perform a clear channel assessment (CCA) or listen before talk (LBT) procedure prior to communicating in order to determine whether the channel is available.
The small cell base station 102'may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell base station 102'may employ LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum as used by the WLAN AP 150. The small cell base station 102', employing LTE /5G in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. NR in unlicensed spectrum may be referred to as NR-U. LTE in an unlicensed spectrum may be referred to as LTE-U, licensed assisted access (LAA) , or MulteFire.
The wireless communications system 100 may further include a millimeter wave (mmW) base station 180 that may operate in mmW frequencies and/or near mmW frequencies in communication with a UE 182. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in this band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band have high path loss and a relatively short range. The mmW base station 180 and the UE 182 may utilize beamforming (transmit and/or receive) over a mmW communication link 184 to compensate for the extremely high path loss and short range. Further, it will be appreciated that in alternative configurations, one or more base stations 102 may also transmit using mmW or near mmW and beamforming. Accordingly, it will be appreciated that the foregoing illustrations are merely examples and should not be construed to limit the various aspects disclosed herein.
Transmit beamforming is a technique for focusing an RF signal in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omni-directionally) . With transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal for the receiving device (s) . To change the directionality of the RF signal when transmitting, a network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that are broadcasting the RF signal. For example, a network node may use an array of antennas (referred to as a “phased array” or an “antenna array” ) that creates a beam of RF waves that can be “steered” to point in different directions, without actually moving the antennas. Specifically, the RF current from the transmitter is fed to the individual antennas with the correct phase relationship so that the radio waves from the separate antennas add together to increase the radiation in a desired direction, while canceling to suppress radiation in undesired directions.
Transmit beams may be quasi-collocated, meaning that they appear to the receiver (e.g., a UE) as having the same parameters, regardless of whether or not the transmitting antennas of the network node themselves are physically collocated. In NR, there are four types of quasi-collocation (QCL) relations. Specifically, a QCL relation of a given type means that certain parameters about a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. Thus, if the source reference RF signal is QCL Type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type D, the receiver can use the source reference RF signal to estimate the spatial receive parameter of a second reference RF signal transmitted on the same channel.
In receive beamforming, the receiver uses a receive beam to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting and/or adjust the phase setting of an array of antennas in a particular direction to amplify (e.g., to increase the gain level of) the RF signals received from that direction. Thus, when a receiver is said to beamform in a certain direction, it means the beam gain in that direction is high relative to the beam gain along other directions, or the beam gain in that direction is the highest compared to the beam gain in that direction of all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP) , reference signal received quality (RSRQ) , signal-to-interference-plus-noise ratio (SINR) , etc. ) of the RF signals received from that direction.
Receive beams may be spatially related. A spatial relation means that parameters for a transmit beam for a second reference signal can be derived from information about a receive beam for a first reference signal. For example, a UE may use a particular receive beam to receive one or more reference downlink reference signals (e.g., positioning reference signals (PRS) , navigation reference signals (NRS) , tracking reference signals (TRS) , phase tracking reference signal (PTRS) , cell-specific reference signals (CRS) , channel state information reference signals (CSI-RS) , primary synchronization signals (PSS) , secondary synchronization signals (SSS) , synchronization signal blocks (SSBs) , etc. ) from a base station. The UE can then form a transmit beam for sending one or more uplink reference signals (e.g., uplink positioning reference signals (UL-PRS) , sounding reference signal (SRS) , demodulation reference signals (DMRS) , PTRS, etc. ) to that base station based on the parameters of the receive beam.
Further note that a “downlink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the downlink beam to transmit a reference signal to a UE, the downlink beam is a transmit beam. If the UE is forming the downlink beam, however, it is a receive beam to receive the downlink reference signal. Similarly, an “uplink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the uplink beam, it is an uplink receive beam, and if a UE is forming the uplink beam, it is an uplink transmit beam.
In 5G, the frequency spectrum in which wireless nodes (e.g., base stations 102/180, UEs 104/182) operate is divided into multiple frequency ranges, FR1 (from 450 to 6000 MHz) , FR2 (from 24250 to 52600 MHz) , FR3 (above 52600 MHz) , and FR4 (between FR1 and FR2) . In a multi-carrier system, such as 5G, one of the carrier frequencies is referred to as the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell, ” and the remaining carrier frequencies are referred to as “secondary carriers” or “secondary serving cells” or “SCells. ” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by a UE 104/182 and the cell in which the UE 104/182 either performs the initial radio resource control (RRC) connection establishment procedure or initiates the RRC connection re-establishment procedure. The primary carrier carries all common and UE-specific control channels, and may be a carrier in a licensed frequency (however, this is not always the case) . A secondary carrier is a carrier operating on a second frequency (e.g., FR2) that may be configured once the RRC connection is established between the UE 104 and the anchor carrier and that may be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier in an unlicensed frequency. The secondary carrier may contain only necessary signaling information and signals, for example, those that are UE-specific may not be present in the secondary carrier, since both primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104/182 in a cell may have different downlink primary carriers. The same is true for the uplink primary carriers. The network is able to change the primary carrier of any UE 104/182 at any time. This is done, for example, to balance the load on different carriers. Because a “serving cell” (whether a PCell or an SCell) corresponds to a carrier frequency /component carrier over which some base station is communicating, the term “cell, ” “serving cell, ” “component carrier, ” “carrier frequency, ” and the like can be used interchangeably.
For example, still referring to FIG. 1, one of the frequencies utilized by the macro cell base stations 102 may be an anchor carrier (or “PCell” ) and other frequencies utilized by the macro cell base stations 102 and/or the mmW base station 180 may be secondary carriers ( “SCells” ) . The simultaneous transmission and/or reception of multiple carriers enables the UE 104/182 to significantly increase its data transmission and/or reception rates. For example, two 20 MHz aggregated carriers in a multi-carrier system would theoretically lead to a two-fold increase in data rate (i.e., 40 MHz) , compared to that attained by a single 20 MHz carrier.
The wireless communications system 100 may further include a UE 164 that may communicate with a macro cell base station 102 over a communication link 120 and/or the mmW base station 180 over a mmW communication link 184. For example, the macro cell base station 102 may support a PCell and one or more SCells for the UE 164 and the mmW base station 180 may support one or more SCells for the UE 164. In addition, the macro cell base station 102 and the mmW base station 180 may be part of different RAN’s (e.g., an LTE network and an NR network, respectively) and/or operate in accordance with different RATs (e.g., LTE and NR, respectively) . As such, UE 164 may be referred to as having “dual connectivity. ” Although only UE 164 is illustrated as having dual connectivity to macro cell base station 102 and the mmW base station 180, this is for simplicity, and any of the other UE’s may also be capable of dual connectivity.
The wireless communications system 100 may further include one or more UEs, such as UE 190, that connects indirectly to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. In the example of FIG. 1, UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which UE 190 may indirectly obtain cellular connectivity) and a D2D P2P link 194 with WLAN STA 152 connected to the WLAN AP 150 (through which UE 190 may indirectly obtain WLAN-based Internet connectivity) . In an example, the D2D P2P links 192 and 194 may be supported with any well-known D2D RAT, such as LTE Direct (LTE-D) , WiFi Direct (WiFi-D) ,
and so on.
FIG. 2A depicts a wireless communications system 200A showing user plane connectivity supporting dual connectivity for a UE 204 (which may correspond to any of the UEs described herein) . Multi-radio dual connectivity (MR-DC) is a generalization of the intra-evolved universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA) dual connectivity, where a UE may be configured to utilize resources provided by two different nodes connected via a backhaul, one providing NR access and the other providing either E-UTRA (i.e., LTE) or NR access. One node acts as the master node (MN) and the other as the secondary node (SN) . The MN and SN are connected via a network interface and at least the MN is connected to the core network. Further, the MN and/or the SN can be operated with shared spectrum channel access.
There are different types of MR-DC. In E-UTRA-NR dual connectivity (EN-DC) , a UE is connected to one eNB that acts as an MN and one en-gNB (anode providing NR user plane and control plane protocol terminations towards the UE) that acts as an SN. The eNB is connected to the EPC via the S1 interface and to the en-gNB via the X2 interface. The en-gNB might also be connected to the EPC via the S1-U interface and other en-gNBs via the X2-U interface. In NG-RAN E-UTRA-NR dual connectivity (NGEN-DC) , a UE is connected to one ng-eNB that acts as an MN and one gNB that acts as an SN. In NR-E-UTRA dual connectivity (NE-DC) , a UE is connected to one gNB that acts as an MN and one ng-eNB that acts as an SN. In NR-NR dual connectivity (NR-DC) , a UE is connected to one gNB that acts as an MN and another gNB that acts as an SN.
FIGS. 2A and 2B illustrate exemplary architectures for EN-DC. However, the disclosure is not limited to EN-DC. Referring to FIG. 2A, when configured for dual connectivity, the UE 204 may be connected to an MN 202A via a communication link 224 and to one or more SNs 202B via a communication link 228. The MN 202A and the SN 202B (collectively, nodes 202) may be cells or TRPs supported by different base stations and may operate according to different RATs (e.g., LTE and NR) . For example, the MN 202A may correspond to a cell supported by one of macro cell base stations 102 in FIG. 1, and the SN 202B may correspond to a cell supported by mmW base station 180 in FIG. 1.
The communication links 224 and 228 may include uplink transmissions from the UE 204 to the nodes 202 and/or downlink transmissions from the nodes 202 to the UE 204. The communication links 224 and 228 may use MIMO antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity, as described above with reference to FIG. 1.
In carrier aggregation (described above with reference to FIG. 1) , one of the carriers utilized by a base station may be a PCell for a UE and other carriers utilized by the same base station (or a difference base station operating according to the same RAT) may be SCells. Dual connectivity, however, is used to achieve carrier aggregation between different base stations, and particularly, different RATs, rather than different cells supported by the same base station. Dual connectivity is well-suited in heterogeneous networks (e.g., a network of macro cells and small cells or a network of cells belonging to different RANs) . In the example of FIG. 2A, the UE 204 is in the PCell 222 served by the MN 202A and the SCell 226 served by the SN 202B.
The wireless communications system 200A may further include other network nodes such as a serving gateway (SGW) 242. The SGW 242 may support a user plane interface, such as a S1-U 244A/244B with nodes 202. The SGW 242 may also support a control plane interface to a mobility management entity (MME) (shown in FIG. 2B) .
FIG. 2B depicts a wireless communications system 200B showing control plane connectivity supporting dual connectivity for the UE 204. In the example of FIG. 2B, the S1-MME 248 interface between the MME 250 and the MN 202A may be used as a control plane for controlling the dual connectivity provided to UE 204. The control plane signaling may also include an interface (not shown) between the MME 250 and the SGW 242.
In the case of dual connectivity, there may different bearer options, including a split bearer option and a secondary cell group (SCG) bearer option. For split bearers, for example, the S1-U interface 244A connection to the SGW 242 may be terminated by the MN 202A, and the MN 202A may split some of the user plane traffic toward the SN 202B via the X2 interface 246. In the case of SCG bearers, for example, the SN 202B may be directly connected to the core network (e.g., core network 170) , while the MN 202B may not be not involved in the transport of user plane data for this type of bearer (s) over the Uu interface (i.e., the radio interface) .
As described in greater detail with reference to FIGS. 3A and 3B, the MN 202A is responsible for radio resource control (RRC) layer (referred to as “Layer 3” ) signaling for the UE 204. However, both the MN 202A and the SN 202B have different physical downlink control channels (PDCCHs) and physical downlink shared channels (PDSCHs) . Data for the UE 204 is split at the packet data convergence protocol (PDCP) layer, but unlike carrier aggregation, the radio link control (RLC) layer and the medium access control (MAC) layer are different for the MN 202A and the SN 202B (the PDCP, RLC, and MAC layers are collectively referred to as “Layer 2” ) .
Under a dual connectivity configuration, the network (e.g., core network 170, application server 172, SGW 242, MME 250) may configure the amount of transmit power a UE 204 can use to transmit on each of the dual communication links 224 and 228. For example, under an EN-DC configuration, the network may configure the maximum power of the LTE (P
LTE) and NR (P
NR) communication links via RRC signaling so that the total transmitted power on the LTE and NR communication links does not exceed the power class of the EN-DC configuration when the UE 204 is transmitting on both links concurrently. A typical example of the transmission power values are P
LTE = P
NR = 20 decibel-milliwatts (dBm) , where the total EN-DC power class is 23 dBm (note that these numbers are in the log domain and if converted to the linear domain, they would be doubled) . However, for LTE standalone, the maximum transmit power may be permitted to reach p-Max-LTE = 23dBm, which is double the maximum LTE transmit power under the EN-DC configuration.
As another example, a UE 204 may use a time-division multiplexing (TDM) pattern in order to transmit on the dual communication links 224 and 228 in turn (one at a time time) . The network may configure the UE 204 with the TDM pattern. For example, under an EN-DC configuration, the network may send a TDM pattern for NR and LTE transmissions to the UE 204. The TDM pattern may specify the length of time (e.g., in slots, subframes, milliseconds, etc. ) that the UE 204 is allowed to transmit on the anchor communication link (e.g., communication link 224) before switching to transmit on the secondary communication link (e.g., communication link 228) , again, for a specified amount of time, before then switching back to the anchor communication link. This allows both LTE and NR transmissions to use a higher power level when it is their turn to transmit (compared to simultaneous transmissions on both links) . The TDM pattern may be selected from one of LTE’s time-division duplexing (TDD) configuration patterns, which can be different from the TDD pattern when the UE operates in LTE standalone mode.
FIG. 3A is a block diagram illustrating generation and transport of RRC messages to a dual connectivity-capable UE 304 (which may correspond to any of the UEs described herein) . FIG. 3A illustrates a cellular network 300, which includes an SN 302B (which may correspond to SN 202B) , an MN 302A (which may correspond to MN 202A) , and a core network 308 (which may correspond to core network 170) . The cellular network 300 may be an LTE network or an NR network. The cellular network 300 can also have components of an LTE network and/or an NR network. For example, the MN 302A may be an LTE MN, and the SN 302B may be an LTE SN.
The UE 304 can be coupled simultaneously to the SN 302B and the MN 302A, meaning the UE 304 is configured for dual connectivity. As such, the UE 304 can generate/transmit data for/to the MN 302A and/or the SN 302B. The UE 304 can also receive/decode data from the MN 302A and/or the SN 302B. Although not shown, the UE 304 may also be coupled to more than two nodes, in which case there could be more than one SN 302B.
FIG. 3A illustrates a control plane protocol architecture for dual connectivity including, in respective nodes or elements, instances of a NAS protocol layer 312-1, 312-2; instances of an RRC protocol layer 314-1, 314-2, 314-3, 314-4; instances of a user plane 316-1, 316-2, 316-3, 316-4; and instances of a physical layer 318-1, 318-2, 318-3, 318-4.A physical protocol layer (or simply “physical layer” or “PHY” ) can include, by way of example and not by limitation, a PDCCH, a physical uplink control channel (PUCCH) , a random access channel (RACH) , a PDSCH, and a physical uplink shared channel (PUSCH) , among other types of channels in the physical layer. As such, control and/or user data can be received by the UE 304 via the MN 302A (e.g., as represented by the connection between the physical layer 318-1 and the physical layer 318-3) and/or via the SN 302B (e.g., as represented by the connection between the physical layer 318-2 and the physical layer 318-4) .
Receiving data from an NR SN has different advantages compared to receiving data from an LTE MN. For example, the NR SN can generate data to be transmitted at a higher frequency and/or larger bandwidth and lower latency than an LTE MN. Transmitting data via a higher frequency/larger bandwidth can include delivery of the data at a faster rate than transmitting data via a lower frequency. However, transmitting data via a higher frequency can include a less reliable delivery of the data as compared to transmitting data via a lower frequency. As such, there may be benefits to delivering data via the SN 302B (where the SN 302B is an NR SN) .
At a high level, in MR-DC, the UE (e.g., UE 304) has a single RRC state, based on the MN RRC and a single control plane connection towards the core network. Each radio node has its own RRC entity 314 (e.g., an E-UTRA version if the node is an eNB or an NR version if the node is a gNB) that can generate RRC protocol data units (PDUs) to be sent to the UE 304. RRC PDUs generated by the SN 302B can be transported via the MN 302A to the UE 304. The MN 302A always sends the initial SN RRC configuration via the master cell group (MCG) signaling radio bearer (SRB) (i.e., SRB1) , but subsequent reconfigurations may be transported via the MN 302A or the SN 302B. When transporting RRC PDUs from the SN 302B, the MN 302A does not modify the UE configuration provided by the SN 302B.
In E-UTRA connected to EPC dual connectivity (i.e., EN-DC) , at initial connection establishment, SRB1 uses E-UTRA PDCP. If the UE 304 supports EN-DC, regardless of whether EN-DC is configured or not, after initial connection establishment, MCG SRBs (SRB1 and SRB2) can be configured by the network to use either E-UTRA PDCP or NR PDCP (either SRB1 and SRB2 are both configured with E-UTRA PDCP, or they are both configured with NR PDCP) . Changes from E-UTRA PDCP to NR PDCP (or vice-versa) is supported via a handover procedure (reconfiguration with mobility) or, for the initial change of SRB1 from E-UTRA PDCP to NR PDCP, with a reconfiguration without mobility before the initial security activation.
If the SN 302B is a gNB (i.e. for EN-DC, NGEN-DC, and NR-DC) , the UE 304 can be configured to establish an SRB with the SN 302B (SRB3) to enable RRC PDUs for the SN to be sent directly between the UE 304 and the SN 302B. RRC PDUs for the SN 302B can only be transported directly to the UE 304 for SN RRC reconfiguration not requiring any coordination with the MN 302A. Measurement reporting for mobility within the SN 302B can be done directly from the UE 304 to the SN 302B if SRB3 is configured.
Split SRB is supported for all MR-DC options, allowing duplication of RRC PDUs generated by the MN 302A, via a direct path and via the SN 302B. Split SRB uses NR PDCP.
In EN-DC, the secondary cell group (SCG) configuration is kept in the UE 304 during suspension. During connection resumption, if the UE 304 supports resuming with EN-DC, the UE 304 can be configured to release, restore, or reconfigure the SCG configuration. Otherwise, the UE 304 releases the SCG configuration (but not the radio bearer configuration) during resumption initiation.
In MR-DC with 5GC, the UE 304 stores the PDCP/SDAP (service data adaptation protocol) configuration and the SCG configuration when moving to the RRC inactive state. During connection resumption, if the UE 304 supports resuming with MR-DC, the UE 304 can be configured to release, restore, or reconfigure the SCG configuration. Otherwise, it releases the SCG configuration.
Referring to FIG. 3A in greater detail, an RRC message originating in the MN 302A, such as an RRC message generated by the instance of the RRC protocol layer 314-1, is delivered to the UE 304 directly via the MN 302A or via the SN 302B. An RRC message originating in the MN 302A can also be delivered to the UE 304 over a mixture of the MN 302A and the SN 302B. This can also involve duplicates of the RRC messages being sent over MN 302A and the SN 302B, for diversity.
An RRC message originating in the SN 302B, such as an RRC message generated by the instance of the RRC protocol layer 314-2, can be delivered to the UE 304 directly via the SN 302B or via the MN 302A. For example, a first RRC message originating in the SN 302B can be sent to and incorporated into a second RRC message originating in the MN 302A. The second RRC message originating in the MN 302A can then be sent either through the user plane 316-1 and physical layer 318-1, the user plane 316-2 and the physical layer 318-2, or a mixture of both the user planes 316-1, 316-2 and the respective physical layers 318-1, 318-2.
A NAS message originating in the core network 308 (e.g., from the instance of the NAS protocol layer 312-1) can be transferred to the RRC protocol layer 314-1 of the MN 302A. In some examples, the core network 308 can include an MME (e.g., MME 250) in an EPC of a 3G or 4G LTE network and/or a similar entity in a 5G core network (5GC) . The NAS message can be incorporated into an RRC message by the instance of the RRC protocol layer 314-1. The RRC message generated by the instance of the RRC protocol layer 314-1 can be processed through the user plane 316-1 and/or the user plane 316-2.
The user planes 316-1, 316-2, 316-3, 316-4 can include a PDCP layer, an RLC layer, and/or a MAC layer. The RRC message originating in the RRC protocol layer 314-1 of the MN 302A can be processed through the user plane 316-1 and provided directly to the UE 304 via the physical layer 318-1. The RRC message originating in the RRC protocol layer 314-1 can also be processed through the user plane 316-1 and the user plane 316-2, and provided (e.g., provided indirectly) via the physical layer 318-2.
An RRC message originating in the instance of the RRC protocol layer 314-2 of the SN 302B can be processed through the user plane 316-2 and sent directly to the UE 304 via the physical layer 318-2. Alternatively, the RRC message originating in the instance of the RRC protocol layer 314-2 of the SN 302B can be processed through the user plane 316-1 of the MN 302A.
The UE 304 can receive data through the physical layer 318-3 and/or the physical layer 318-4. The physical layer 318-3 and the physical layer 318-4 can correspond to the physical layer 318-1 and the physical layer 318-2, respectively. The UE 304 can decrypt the data received via the physical layers 318-3 and 318-4 to identify an RRC message and/or RRC messages originating from the RRC protocol layer 314-1 and/or the RRC protocol layer 314-2. The UE 304 can process the RRC messages through the user planes 316-3 and/or 316-4.
The UE 304 can provide the RRC messages originating from the RRC protocol layers 314-1 and/or 314-2 to the RRC protocol layers 314-3 and 314-4 after processing the RRC messages through the user planes 316-3 and/or 316-4. In some examples, an RRC message can be processed through the user plane 316-3 before being processed through the user plane 316-4. An RRC message can also be processed through all or part of the user plane 316-4 before being processed through part of the user plane 316-3. The RRC protocol layer 314-3 and/or the RRC protocol layer 314-4 can process the RRC messages originating from the RRC protocol layers 314-1 and/or 314-2.
In some examples, the RRC protocol layer 314-4 can generate an RRC message based on the RRC message originating from the RRC protocol layer 314-1. The RRC protocol layer 314-4 can also provide the generated RRC message to the RRC protocol layer 314-3. The RRC protocol layer 314-4 can also process and respond with RRC messages to an RRC message originating from the RRC protocol layer 314-2.
The RRC protocol layer 314-3 can generate an RRC message based on the RRC message originating from the RRC protocol layer 314-2. The RRC protocol layer 314-3 can also generate an encapsulated RRC message on receipt of RRC messages from the RRC protocol layer 314-4. In some examples, the RRC protocol layer 314-3 can also process and respond with RRC messages to an RRC message originating from the RRC protocol layer 314-1, which may include and/or encapsulate a NAS message originating from the NAS protocol layer 312-1 of the core network 308. The RRC protocol layer 314-3 can provide the NAS message to the NAS protocol layer 312-2 of the UE 304 for processing. The RRC messages from the RRCs 314-3 and 314-4 may be transferred over either of the user plane 316-4 or 316-3 or a combination of the user planes 316-4 and 316-3.
FIG. 3B is a block diagram illustrating an example user plane architecture for dual connectivity. The example user plane architecture may be used, for example, for the instances of the user planes 316-1, 316-2 shown in FIG. 3A. As such, FIG. 3B includes the MN 302A and the SN 302B shown in FIG. 3A. However, as will be appreciated, the example user plane architecture shown in FIG. 3B could also be used for the instances of the user planes 316-3, 316-4 of the UE 304 shown in FIG. 3A. It will also be appreciated that each of the MN 302A and the SN 302B can include one or more user planes, and that the UE 304 can include a single user plane or more than two user planes.
At a high level, in MR-DC, from a UE perspective, three bearer types exist: MCG bearer, SCG bearer, and split bearer. In E-UTRA connected to EPC dual connectivity, if the UE 304 supports EN-DC, regardless of whether EN-DC is configured or not, the network can configure either E-UTRA PDCP or NR PDCP for MN-terminated MCG bearers, while NR PDCP is used for all other bearers. In MR-DC with 5GC, NR PDCP is used for all bearer types. In NGEN-DC, E-UTRA RLC/MAC is used in the MN 302A while NR RLC/MAC is used in the SN 302B. In NE-DC, NR RLC/MAC is used in the MN 302A, while E-UTRA RLC/MAC is used in the SN 302B. In NR-DC, NR RLC/MAC is used in both the MN 302A and the SN 302B.
From a network perspective, each bearer (MCG, SCG, and split bearer) can be terminated either in the MN 302A or in the SN 302B. Note that even if only SCG bearers are configured for a UE 304, for SRB1 and SRB2 the logical channels are always configured at least in the MCG (i.e. this is still an MR-DC configuration and a PCell always exists) . Further, if only MCG bearers are configured for a UE 304 (i.e. there is no SCG) , this is still considered an MR-DC configuration, as long as at least one of the bearers is terminated in the SN 302B.
Referring to FIG. 3B in greater detail, the MN 302A shown in FIG. 3B includes a user plane comprising a PDCP layer 323-1, an RLC layer 325-1, and a MAC layer 327-1. The MN 302A can also include a user plane comprising a PDCP layer 323-2, an RLC layer 325-2, and a MAC protocol layer 327-1. A master cell group (MCG) bearer 329-1 can use the PDCP protocol layer 323-1, the RLC protocol layer 325-1, and the MAC protocol layer 327-1. The MCG bearer 329-1 can carry traffic received for a bearer or quality of service (QoS) flow over the S1 interface. A split bearer 329-2 can use the PDCP layer 323-2, the RLC layer 325-2, and the MAC layer 327-1. In some examples, the split bearer 329-2 can use a PDCP layer 323-2, an RLC layer 325-3, and a MAC layer 327-2. A split bearer can also use a combination of the PDCP layer 323-2 with RLC layer 325-2, the MAC layer 327-1 and an RLC layer 325-3, and a MAC layer 327-2.The split bearer 329-2 can be implemented using the X2 or similar interfaces. A split bearer can receive traffic over an S1 interface or RRC messages as discussed above.
As also shown in FIG. 3B, the SN 302B includes a user plane comprising a PDCP layer 323-3, an RLC layer 325-4, and the MAC layer 327-2. An SCG bearer 329-3 can use the PDCP protocol layer 323-3, the RLC protocol layer 325-4, and the MAC protocol layer 327-2. The SCG bearer 329-3 can carry traffic received over the S1 interface or RRC messages originating in an SN 302B.
Additional details regarding MR-DC can be found in Third Generation Partnership Project (3GPP) Technical Specification (TS) 37.340, which is publicly available and incorporated by reference herein in its entirety.
FIGS. 4A, 4B, and 4C illustrate several exemplary components (represented by corresponding blocks) that may be incorporated into a UE 402 (which may correspond to any of the UEs described herein) , a base station 404 (which may correspond to any of the base stations described herein) , and a network entity 406 (which may correspond to or embody any of the network functions described herein) to support the file transmission operations as taught herein. It will be appreciated that these components may be implemented in different types of apparatuses in different implementations (e.g., in an ASIC, in a system-on-chip (SoC) , etc. ) . The illustrated components may also be incorporated into other apparatuses in a communication system. For example, other apparatuses in a system may include components similar to those described to provide similar functionality. Also, a given apparatus may contain one or more of the components. For example, an apparatus may include multiple transceiver components that enable the apparatus to operate on multiple carriers and/or communicate via different technologies.
The UE 402 and the base station 404 each include wireless wide area network (WWAN) transceiver 410 and 450, respectively, configured to communicate via one or more wireless communication networks (not shown) , such as an NR network, an LTE network, a GSM network, and/or the like. The WWAN transceivers 410 and 450 may be connected to one or more antennas 416 and 456, respectively, for communicating with other network nodes, such as other UEs, access points, base stations (e.g., ng-eNBs, gNBs) , etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc. ) over a wireless communication medium of interest (e.g., some set of time/frequency resources in a particular frequency spectrum) . The WWAN transceivers 410 and 450 may be variously configured for transmitting and encoding signals 418 and 458 (e.g., messages, indications, information, and so on) , respectively, and, conversely, for receiving and decoding signals 418 and 458 (e.g., messages, indications, information, pilots, and so on) , respectively, in accordance with the designated RAT. Specifically, the transceivers 410 and 450 include one or more transmitters 414 and 454, respectively, for transmitting and encoding signals 418 and 458, respectively, and one or more receivers 412 and 452, respectively, for receiving and decoding signals 418 and 458, respectively.
The UE 402 and the base station 404 also include, at least in some cases, wireless local area network (WLAN) transceivers 420 and 460, respectively. The WLAN transceivers 420 and 460 may be connected to one or more antennas 426 and 466, respectively, for communicating with other network nodes, such as other UEs, access points, base stations, etc., via at least one designated RAT (e.g., WiFi, LTE-D,
etc. ) over a wireless communication medium of interest. The WLAN transceivers 420 and 460 may be variously configured for transmitting and encoding signals 428 and 468 (e.g., messages, indications, information, and so on) , respectively, and, conversely, for receiving and decoding signals 428 and 468 (e.g., messages, indications, information, pilots, and so on) , respectively, in accordance with the designated RAT. Specifically, the transceivers 420 and 460 include one or more transmitters 424 and 464, respectively, for transmitting and encoding signals 428 and 468, respectively, and one or more receivers 422 and 462, respectively, for receiving and decoding signals 428 and 468, respectively.
Transceiver circuitry including at least one transmitter and at least one receiver may comprise an integrated device (e.g., embodied as a transmitter circuit and a receiver circuit of a single communication device) in some implementations, may comprise a separate transmitter device and a separate receiver device in some implementations, or may be embodied in other ways in other implementations. In an aspect, a transmitter may include or be coupled to a plurality of antennas (e.g., antennas 416, 426, 456, 466) , such as an antenna array, that permits the respective apparatus to perform transmit “beamforming, ” as described herein. Similarly, a receiver may include or be coupled to a plurality of antennas (e.g., antennas 416, 426, 456, 466) , such as an antenna array, that permits the respective apparatus to perform receive beamforming, as described herein. In an aspect, the transmitter and receiver may share the same plurality of antennas (e.g., antennas 416, 426, 456, 466) , such that the respective apparatus can only receive or transmit at a given time, not both at the same time. A wireless communication device (e.g., one or both of the transceivers 410 and 420 and/or 450 and 460) of the UE 402 and/or the base station 404 may also comprise a network listen module (NLM) or the like for performing various measurements.
In an aspect, where the UE 402 is configured for dual connectivity, the WWAN transceiver 410 may comprise at least two WWAN transceivers, one configured to operate in accordance with a first RAT (e.g., LTE) and one configured to operate in accordance with a second RAT (e.g., NR) . Alternatively, the UE 402 may include a single WWAN transceiver 410 that includes at least two receivers 412 and at least two transmitters 414, a first pair of a receiver and transmitter configured to operate in accordance with a first RAT (e.g., LTE) and a second pair of a receiver and transmitter configured to operate in accordance with a second RAT (e.g., NR) . As yet another alternative, the WWAN transceiver 410 may have a single receiver 412 and a single transmitter 414 that are configured to operate in accordance with both a first RAT (e.g., LTE) and a second RAT (e.g., NR) using, for example, TDM.
The UE 402 and the base station 404 may also include, at least in some cases, satellite positioning systems (SPS) receivers 430 and 470. The SPS receivers 430 and 470 may be connected to one or more antennas 436 and 476, respectively, for receiving SPS signals 438 and 478, respectively, such as global positioning system (GPS) signals, global navigation satellite system (GLONASS) signals, Galileo signals, Beidou signals, Indian Regional Navigation Satellite System (NAVIC) , Quasi-Zenith Satellite System (QZSS) , etc. The SPS receivers 430 and 470 may comprise any suitable hardware and/or software for receiving and processing SPS signals 438 and 478, respectively. The SPS receivers 430 and 470 request information and operations as appropriate from the other systems, and performs calculations necessary to determine positions of the UE 402 and the base station 404 using measurements obtained by any suitable SPS algorithm.
The base station 404 and the network entity 406 each include at least one network interfaces 480 and 490 for communicating with other network entities. For example, the network interfaces 480 and 490 (e.g., one or more network access ports) may be configured to communicate with one or more network entities via a wire-based or wireless backhaul connection. In some aspects, the network interfaces 480 and 490 may be implemented as transceivers configured to support wire-based or wireless signal communication. This communication may involve, for example, sending and receiving messages, parameters, and/or other types of information.
The UE 402, the base station 404, and the network entity 406 also include other components that may be used in conjunction with the operations as disclosed herein. The UE 402 includes processor circuitry implementing a processing system 432 for providing functionality relating to, for example, positioning operations, and for providing other processing functionality. The base station 404 includes a processing system 484 for providing functionality relating to, for example, positioning operations as disclosed herein, and for providing other processing functionality. The network entity 406 includes a processing system 494 for providing functionality relating to, for example, positioning operations as disclosed herein, and for providing other processing functionality. In an aspect, the processing systems 432, 484, and 494 may include, for example, one or more general purpose processors, multi-core processors, ASICs, digital signal processors (DSPs) , field programmable gate arrays (FPGA) , or other programmable logic devices or processing circuitry.
The UE 402, the base station 404, and the network entity 406 include memory circuitry implementing memory components 440, 486, and 496 (e.g., each including a memory device) , respectively, for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, and so on) . In some cases, the UE 402, the base station 404, and the network entity 406 may include cell selection components 442, 488, and 498, respectively. The cell selection components 442, 488, and 498 may be hardware circuits that are part of or coupled to the processing systems 432, 484, and 494, respectively, that, when executed, cause the UE 402, the base station 404, and the network entity 406 to perform the functionality described herein. In other aspects, the cell selection components 442, 488, and 498 may be external to the processing systems 432, 484, and 494 (e.g., part of a modem processing system, integrated with another processing system, etc. ) . Alternatively, the cell selection components 442, 488, and 498 may be memory modules (as shown in FIGS. 4A-C) stored in the memory components 440, 486, and 496, respectively, that, when executed by the processing systems 432, 484, and 494 (or a modem processing system, another processing system, etc. ) , cause the UE 402, the base station 404, and the network entity 406 to perform the functionality described herein.
The UE 402 may include one or more sensors 444 coupled to the processing system 432 to provide movement and/or orientation information that is independent of motion data derived from signals received by the WWAN transceiver 410, the WLAN transceiver 420, and/or the SPS receiver 430. By way of example, the sensor (s) 444 may include an accelerometer (e.g., a micro-electrical mechanical systems (MEMS) device) , a gyroscope, a geomagnetic sensor (e.g., a compass) , an altimeter (e.g., a barometric pressure altimeter) , and/or any other type of movement detection sensor. Moreover, the sensor (s) 444 may include a plurality of different types of devices and combine their outputs in order to provide motion information. For example, the sensor (s) 444 may use a combination of a multi-axis accelerometer and orientation sensors to provide the ability to compute positions in 2D and/or 3D coordinate systems.
In addition, the UE 402 includes a user interface 446 for providing indications (e.g., audible and/or visual indications) to a user and/or for receiving user input (e.g., upon user actuation of a sensing device such a keypad, a touch screen, a microphone, and so on) . Although not shown, the base station 404 and the network entity 406 may also include user interfaces.
Referring to the processing system 484 in more detail, in the downlink, IP packets from the network entity 406 may be provided to the processing system 484. The processing system 484 may implement functionality for an RRC layer, a PDCP layer, an RLC layer, and a MAC layer. The processing system 484 may provide RRC layer functionality associated with broadcasting of system information (e.g., master information block (MIB) , system information blocks (SIBs) ) , RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release) , inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification) , and handover support functions; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through automatic repeat request (ARQ) , concatenation, segmentation, and reassembly of RLC service data units (SDUs) , re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.
The transmitter 454 and the receiver 452 may implement Layer-1 functionality associated with various signal processing functions. Layer-1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The transmitter 454 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK) , quadrature phase-shift keying (QPSK) , M-phase-shift keying (M-PSK) , M-quadrature amplitude modulation (M-QAM) ) . The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 402. Each spatial stream may then be provided to one or more different antennas 456. The transmitter 454 may modulate an RF carrier with a respective spatial stream for transmission.
At the UE 402, the receiver 412 receives a signal through its respective antenna (s) 416. The receiver 412 recovers information modulated onto an RF carrier and provides the information to the processing system 432. The transmitter 414 and the receiver 412 implement Layer-1 functionality associated with various signal processing functions. The receiver 412 may perform spatial processing on the information to recover any spatial streams destined for the UE 402. If multiple spatial streams are destined for the UE 402, they may be combined by the receiver 412 into a single OFDM symbol stream. The receiver 412 then converts the OFDM symbol stream from the time-domain to the frequency domain using a fast Fourier transform (FFT) . The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 404. These soft decisions may be based on channel estimates computed by a channel estimator. The soft decisions are then decoded and de-interleaved to recover the data and control signals that were originally transmitted by the base station 404 on the physical channel. The data and control signals are then provided to the processing system 432, which implements Layer-3 and Layer-2 functionality.
In the uplink, the processing system 432 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network. The processing system 432 is also responsible for error detection.
Similar to the functionality described in connection with the downlink transmission by the base station 404, the processing system 432 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs) , demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ) , priority handling, and logical channel prioritization.
Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station 404 may be used by the transmitter 414 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the transmitter 414 may be provided to different antenna (s) 416. The transmitter 414 may modulate an RF carrier with a respective spatial stream for transmission.
The uplink transmission is processed at the base station 404 in a manner similar to that described in connection with the receiver function at the UE 402. The receiver 452 receives a signal through its respective antenna (s) 456. The receiver 452 recovers information modulated onto an RF carrier and provides the information to the processing system 484.
In the uplink, the processing system 484 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 402. IP packets from the processing system 484 may be provided to the core network. The processing system 484 is also responsible for error detection.
For convenience, the UE 402, the base station 404, and/or the network entity 406 are shown in FIGS. 4A-C as including various components that may be configured according to the various examples described herein. It will be appreciated, however, that the illustrated blocks may have different functionality in different designs.
The various components of the UE 402, the base station 404, and the network entity 406 may communicate with each other over data buses 434, 482, and 492, respectively. The components of FIGS. 4A-C may be implemented in various ways. In some implementations, the components of FIGS. 4A-C may be implemented in one or more circuits such as, for example, one or more processors and/or one or more ASICs (which may include one or more processors) . Here, each circuit may use and/or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, some or all of the functionality represented by blocks 410 to 446 may be implemented by processor and memory component (s) of the UE 402 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components) . Similarly, some or all of the functionality represented by blocks 450 to 488 may be implemented by processor and memory component (s) of the base station 404 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components) . Also, some or all of the functionality represented by blocks 490 to 498 may be implemented by processor and memory component (s) of the network entity 406 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components) . For simplicity, various operations, acts, and/or functions are described herein as being performed “by a UE, ” “by a base station, ” “by a network entity, ” etc. However, as will be appreciated, such operations, acts, and/or functions may actually be performed by specific components or combinations of components of the UE, base station, positioning entity, etc., such as the processing systems 432, 484, 494, the transceivers 410, 420, 450, and 460, the memory components 440, 486, and 496, the cell selection components 442, 488, and 498, etc.
An NR network may operate as either a standalone (SA) network or a non-standalone (NSA) network. An NR SA network is designed to provide NR connectivity without having to utilize existing network architecture (e.g., a legacy LTE network) , and includes a 5GC. In such a network, legacy carriers (e.g., LTE, 3G, GSM, etc. ) can be used as secondary carriers, while the NR carrier can be used for the anchor carrier. As will be appreciated, an LTE network can also operate in either SA or NSA mode.
In an NSA NR network, a UE connects to an LTE eNB as the master node (e.g., MN 202A, MN 302A) for mobility management and coverage, and one or more additional NR gNBs as secondary nodes (e.g., SN 202B, SN 302B) for enhanced coverage and/or throughput, as in the examples of FIGS. 2A and 2B. This solution enables operators to provide NR services sooner and at lower cost. More specifically, NR infrastructure (e.g., gNB physical sites) can be added to geographic areas currently served by LTE networks, thereby providing both LTE and NR service in those areas. Legacy UEs (i.e., those only capable of LTE or earlier network access) can connect to the existing LTE networks, while dual connectivity UEs can connect to both the LTE and NR networks.
When operating in an NSA NR network, it may sometimes take longer than normal for a UE to gain NR access, or it may not be able to gain NR access at all, while other UEs in the region are able to gain NR access normally. This can occur because the UE has attached to an LTE cell (as the MN) that does not support NR dual connectivity (DCNR) . When the UE attempts to perform cell reselection or a new device registration process to attach to a DCNR-capable MN, the network may send a “restrict DCNR” message to the UE, forcing the UE to operate in an LTE-only mode. The term “DCNR” refers to any type of NSA NR dual connectivity where the MN is an LTE cell and the SN is an NR cell, such as EN-DC and NGEN-DC. Thus, in this scenario, the UE is being informed that the LTE cell to which it has attached as the MN does not support dual connectivity with an NR SN.
This type of situation can occur due to the NR deployment not covering the entirety of the geographic region in which the UE is located. Since it may be some time before there is full NR coverage in the region, there needs to be a solution for customers in the area to more reliably gain NR access.
Accordingly, the present disclosure provides techniques for quickly selecting a DCNR-capable LTE cell as the MN for NSA NR dual connectivity. In an aspect, when a UE receives a “restrict DCNR” message from the network for a particular LTE cell, the UE can record the cell ID (e.g., PCI, VCI, CGI) and lower its priority for subsequent cell registrations and reselections. The UE may store the cell ID in a list of other such cell IDs (referred to herein as the “RestrictDCNR_Cell_List” ) . The UE can then trigger cell reselection until it attaches to an LTE cell with DCNR capability (or until it has performed some number of cell reselection attempts) . Upon attaching to an LTE cell that supports DCNR, the UE is then provided NSA NR service.
FIG. 5 illustrates an exemplary method 500 for selecting a DCNR-capable LTE cell as the MN for NSA NR dual connectivity, according to aspects of the disclosure. In the example of FIG. 5, a UE 504 is attempting to attach to an LTE cell that will be an MN for an NSA NR dual connectivity session. The method 500 may be performed between the UE 504 (e.g., any of the UEs described herein) and a first LTE cell 502A (labelled “LTE Cell_1” ) and a second LTE cell 502B (labelled “LTE Cell_2” ) . The LTE cells 502 may be LTE cells supported by any two of the base stations described herein. The operations performed by the UE 504 are more specifically performed by the modem of the UE 504, which may include one or more transceivers (e.g., WWAN transceiver 410) and/or two or more pairs of receivers and transmitters (e.g., one or more pairs of receiver 412 and transmitter 414) .
At 510, the UE 504 sends an attachment request ( “ATTACH REQUEST” ) to the first LTE cell 502A. The attachment request includes an indication that the UE 504 is attempting to establish a connection with an LTE cell that supports DCNR (as indicated by the field “DCNR support” ) .
At 512, the first LTE cell 502A responds to the attachment request with an attachment acceptance message ( “ATTACH ACCEPT” ) . However, the attachment acceptance message includes an indication that the first LTE cell 502A does not support NSA NR dual connectivity (as indicated by the field “restrict DCNR” ) .
At 514, the UE 504 adds the cell ID (e.g., PCI, VCI, CGI) of the first LTE cell 502A to a list of LTE cells that do not support NSA NR dual connectivity (referred to as the “RestrictDCNR_Cell_List” ) . The UE 504 may store the list in local memory (e.g., memory component 440) .
At 516, because the first LTE cell 502A does not support DCNR, the UE 504 decides to reselect to a different LTE cell, i.e., the second LTE cell 502B. The UE 504 may identify the second LTE cell 502B based on a cell search performed by the UE 504 before the method 500 (e.g., when the UE 504 entered the geographic region containing LTE cells 502A and 502B) . The signal strength of the signals received from the second LTE cell 502B should be high enough to support reliable (at least within a QoS threshold) wireless communication between the UE 504 and the second LTE cell 502B. Thus, while the second LTE cell 502B may not have been the UE’s 504 first choice for network access, it is an acceptable second choice for network access.
At 518, the UE 504 may send an attachment request ( “ATTACH REQUEST” ) to the second LTE cell 502B. The attachment request includes an indication that the UE 504 is attempting to establish a connection with an LTE cell that supports DCNR (as indicated by the field “DCNR support” ) . Alternatively, the UE 504 may send a tracking area update request ( “TRACKING_AREA_UPDATE_REQ” ) to the second LTE cell 502B. Like the attachment request, the tracking area update request includes an indication that the UE 504 is attempting to establish a connection with an LTE cell that supports DCNR (as indicated by the field “DCNR support” ) .
The UE 504 may send a tracking area update request instead of an attachment request if the UE 504 is already attached to the network via another cell. More specifically, if the UE 504 attaches to the network via the first LTE cell 502A at 512, the UE 504 may send a tracking area update request at 518. However, if the UE 504 drops, or does not establish, the connection to the network via the first LTE cell 502A (e.g., because it cannot maintain that connection while attaching to the second LTE cell 502B) , then the UE 504 may send an attachment request at 518.
A tracking area is a geographical combination of several base stations (e.g., eNBs in LTE) . A UE (e.g., UE 504) triggers a tracking area update after the UE completes an attachment procedure and moves into a mobility management registered state. A tracking area update indicates to the network that the UE 504 has moved from one cell (e.g., first LTE cell 502A) to another cell (e.g., second LTE cell 502B) .
At 520, if the UE 504 sent an attachment request at 518, then the second LTE cell 502B responds to the attachment request with an attachment acceptance message ( “ATTACH ACCEPT” ) . The attachment acceptance message includes an indication that the second LTE cell 502B supports NSA NR dual connectivity (as indicated by the field “DCNR_support” ) . Alternatively, if the UE 504 sent a tracking area update request at 518, then at 520, the second LTE cell 502B responds to the tracking area update request with a tracking area update acceptance ( “TRACKING_AREA_UPDATE_ACCEPT” ) . Like the attachment acceptance message, the tracking area update acceptance includes an indication that the second LTE cell 502B supports NSA NR dual connectivity (as indicated by the field “DCNR_support” ) .
At the end of method 500, the UE 504 is attached to the second LTE cell 502B as an MN, and can then be configured by the network for NSA NR dual connectivity with one or more SNs (not shown) . Although FIG. 5 illustrates only two LTE cells, as will be appreciated, the method 500 may be performed with any number of LTE cells until the UE 504 successfully connects to an LTE cell that supports DCNR. Alternatively, the method 500 may end after some number of attempts to connect to an LTE cell that supports DCNR have failed. Upon such a failure, the UE 504 may simply (re) connect to the best available LTE cell.
Due to mobility, the UE 504 may eventually disconnect from the second LTE cell 502B and move to another geographic region, where it can repeat method 500 with other LTE cells. Upon returning to the geographic region containing LTE cells 502A and 502B, and discovering LTE cells 502A and 502B after performing a cell search in that region, the UE 504 consults the RestrictDCNR_Cell_List. Based on the cell ID of the first LTE cell 502A being stored in the RestrictDCNR_Cell_List, the UE 504 selects the second LTE cell 502B to attach to the network, even though the first LTE cell 502A may have otherwise been the higher priority, or more preferred, cell (e.g., due to higher signal strength) .
More generally, after performing a cell search and discovering available LTE cells to which the UE 504 can attach, the UE 504 may order the cells according to the priority of connecting to each cell. For example, the UE 504 may order the discovered cells by their respective signal strengths, with cells having higher signal strengths having a higher priority. The UE 504 then checks the RestrictDCNR_Cell_List for the discovered cells, starting with the highest priority cell. If a discovered cell appears on the RestrictDCNR_Cell_List, the UE 504 does not connect to it and checks whether or not the next discovered cell is on the RestrictDCNR_Cell_List. When the UE 504 determines that a discovered cell is not on the RestrictDCNR_Cell_List, the UE 504 connects to that cell. Thus, by maintaining the RestrictDCNR_Cell_List, the UE 504 can more quickly connect to an LTE cell that supports NSA NR dual connectivity.
In an aspect, the UE 504 may remove a cell ID from the RestrictDCNR_Cell_List after it has been on the list for some threshold period of time (e.g., days, months) . This allows for the possibility of network updates, such as an LTE cell that did not support DCNR when the UE 504 first attempted to connect to it later being upgraded to support DCNR.
In an aspect, the network may provide the RestrictDCNR_Cell_List to the UE 504, rather than the UE 504 generating it over time. The UE 504 may receive the list from a network entity, such as the application server 172, SGW 242, MME 250, or other component of the core network 170.
FIG. 6 illustrates an exemplary method 600 of wireless communication, according to aspects of the disclosure. In an aspect, the method 600 may be performed by any of the UEs described herein.
At 610, the UE discovers a first cell (e.g., LTE cell 502A) operating in accordance with a first RAT (e.g., LTE) . The UE may discover the first cell during a cell search procedure. The UE may or may not camp on the first cell. In an aspect, operation 610 may be performed by WWAN transceiver 410, processing system 432, memory component 440, and/or cell selection component 442, any or all of which may be considered means for performing this operation.
At 620, the UE determines that the first cell does not support NSA access for a second RAT (e.g., NR) , as at, for example, 512 of FIG. 5. In an aspect, operation 620 may be performed by WWAN transceiver 410, processing system 432, memory component 440, and/or cell selection component 442, any or all of which may be considered means for performing this operation.
At 630, in response to determining that the first cell does not support NSA access for the second RAT at 620, the UE connects to a second cell (e.g., LTE cell 502B) operating in accordance with the first RAT, as at, for example, 518 and 520 of FIG. 5. In an aspect, the second cell supports NSA access for the second RAT (e.g., EN-DC and NGEN-DC) . In an aspect, operation 630 may be performed by WWAN transceiver 410, processing system 432, memory component 440, and/or cell selection component 442, any or all of which may be considered means for performing this operation.
Those of skill in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
Further, those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.
The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
The methods, sequences and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in random access memory (RAM) , flash memory, read-only memory (ROM) , erasable programmable ROM (EPROM) , electrically erasable programmable ROM (EEPROM) , registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., UE) . In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.
In one or more exemplary aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
While the foregoing disclosure shows illustrative aspects of the disclosure, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. The functions, steps and/or actions of the method claims in accordance with the aspects of the disclosure described herein need not be performed in any particular order. Furthermore, although elements of the disclosure may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.
Claims (32)
- A method of wireless communication performed by a user equipment (UE) , comprising:discovering a first cell operating in accordance with a first radio access technology (RAT) ;determining that the first cell does not support non-standalone (NSA) access for a second RAT; andin response to determining that the first cell does not support NSA access for the second RAT, connecting to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
- The method of claim 1, wherein the first RAT comprises Long-Term Evolution (LTE) and the second RAT comprises New Radio (NR) .
- The method of claim 1, wherein the determining comprises:determining that a cell identifier of the first cell is present in a list of cells that do not support NSA access for the second RAT.
- The method of claim 3, wherein the cell identifier of the first cell is present in the list of cells based on the UE previously determining that the first cell does not support NSA access for the second RAT.
- The method of claim 3, further comprising:receiving the list of cells from a network entity.
- The method of claim 3, wherein cell identifiers listed in the list of cells that do not support NSA access for the second RAT are ordered according to priority of cells corresponding to the cell identifiers.
- The method of claim 1, wherein the determining comprises:receiving an indication from the first cell that the first cell does not support NSA access for the second RAT.
- The method of claim 7, further comprising:in response to receiving the indication, storing a cell identifier of the first cell in a list of cells that do not support NSA access for the second RAT.
- The method of claim 7, further comprising:transmitting a network attachment request to the first cell, wherein the indication is received in response to the network attachment request.
- The method of claim 7, wherein the indication is included in a network attachment acceptance received from the first cell.
- The method of claim 1, wherein the connecting comprises:transmitting a network attachment request to the second cell; andreceiving a network attachment acceptance from the second cell, the network attachment acceptance including an indication that the second cell supports NSA access for the second RAT.
- The method of claim 1, further comprising:transmitting a tracking area update request to the second cell; andreceiving a tracking area update response from the second cell, the tracking area update response including an indication that the second cell supports NSA access for the second RAT.
- The method of claim 12, further comprising:dropping a connection to the first cell in response to reception of the tracking area update response from the second cell.
- The method of claim 1, wherein the UE discovers the first cell and the second cell during a cell search procedure.
- The method of claim 1, wherein the second cell is a master node for NSA access for the second RAT.
- A user equipment (UE) , comprising:a memory;at least one transceiver; andat least one processor communicatively coupled the memory and the at least one transceiver, the at least one processor configured to:discover a first cell operating in accordance with a first radio access technology (RAT) ;determine that the first cell does not support non-standalone (NSA) access for a second RAT; andconnect, in response to a determination that the first cell does not support NSA access for the second RAT, to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
- The UE of claim 16, wherein the first RAT comprises Long-Term Evolution (LTE) and the second RAT comprises New Radio (NR) .
- The UE of claim 16, wherein the at least one processor being configured to determine comprises the at least one processor being configured to:determine that a cell identifier of the first cell is present in a list of cells that do not support NSA access for the second RAT.
- The UE of claim 18, wherein the cell identifier of the first cell is present in the list of cells based on the UE previously determining that the first cell does not support NSA access for the second RAT.
- The UE of claim 18, wherein the at least one processor is further configured to:receive, via the at least one transceiver, the list of cells from a network entity.
- The UE of claim 18, wherein cell identifiers listed in the list of cells that do not support NSA access for the second RAT are ordered according to priority of cells corresponding to the cell identifiers.
- The UE of claim 16, wherein the at least one processor being configured to determine comprises the at least one processor being configured to:receive, via the at least one transceiver, an indication from the first cell that the first cell does not support NSA access for the second RAT.
- The UE of claim 22, wherein the at least one processor is further configured to:store, in response to reception of the indication, a cell identifier of the first cell in a list of cells that do not support NSA access for the second RAT.
- The UE of claim 22, wherein the at least one processor is further configured to:cause the at least one transceiver to transmit a network attachment request to the first cell, wherein the indication is received in response to the network attachment request.
- The UE of claim 22, wherein the indication is included in a network attachment acceptance received from the first cell.
- The UE of claim 16, wherein the at least one processor being configured to connect comprises the at least one processor being configured to:cause the at least one transceiver to transmit a network attachment request to the second cell; andreceive, via the at least one transceiver, a network attachment acceptance from the second cell, the network attachment acceptance including an indication that the second cell supports NSA access for the second RAT.
- The UE of claim 16, wherein the at least one processor is further configured to:cause the at least one transceiver to transmit a tracking area update request to the second cell; andreceive, via the at least one transceiver, a tracking area update response from the second cell, the tracking area update response including an indication that the second cell supports NSA access for the second RAT.
- The UE of claim 27, wherein the at least one processor is further configured to:drop a connection to the first cell in response to reception of the tracking area update response from the second cell.
- The UE of claim 16, wherein the at least one processor discovers the first cell and the second cell during a cell search procedure.
- The UE of claim 16, wherein the second cell is a master node for NSA access for the second RAT.
- A user equipment (UE) , comprising:means for discovering a first cell operating in accordance with a first radio access technology (RAT) ;means for determining that the first cell does not support non-standalone (NSA) access for a second RAT; andmeans for connecting, in response to determining that the first cell does not support NSA access for the second RAT, to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
- A non-transitory computer-readable medium storing computer-executable instructions, the computer-executable instructions comprising:at least one instruction instructing a user equipment (UE) to discover a first cell operating in accordance with a first radio access technology (RAT) ;at least one instruction instructing the UE to determine that the first cell does not support non-standalone (NSA) access for a second RAT; andat least one instruction instructing the UE to connect, in response to determining that the first cell does not support NSA access for the second RAT, to a second cell operating in accordance with the first RAT, wherein the second cell supports NSA access for the second RAT.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/CN2020/088582 WO2021223057A1 (en) | 2020-05-05 | 2020-05-05 | Selecting dual connectivity cell |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/CN2020/088582 WO2021223057A1 (en) | 2020-05-05 | 2020-05-05 | Selecting dual connectivity cell |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2021223057A1 true WO2021223057A1 (en) | 2021-11-11 |
Family
ID=78467736
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/CN2020/088582 WO2021223057A1 (en) | 2020-05-05 | 2020-05-05 | Selecting dual connectivity cell |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2021223057A1 (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101883407A (en) * | 2010-07-09 | 2010-11-10 | 新邮通信设备有限公司 | Method and device for activating cells accessing different radio access technology (RAT) |
WO2018132047A1 (en) * | 2017-01-11 | 2018-07-19 | Telefonaktiebolaget Lm Ericsson (Publ) | A radio access node, a core network node, an information database and methods of operating the same in different radio access technologies |
US20190069229A1 (en) * | 2017-08-25 | 2019-02-28 | Qualcomm Incorporated | Techniques and apparatuses for search, measurement, and icon display in new radio non-standalone mode |
-
2020
- 2020-05-05 WO PCT/CN2020/088582 patent/WO2021223057A1/en active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101883407A (en) * | 2010-07-09 | 2010-11-10 | 新邮通信设备有限公司 | Method and device for activating cells accessing different radio access technology (RAT) |
WO2018132047A1 (en) * | 2017-01-11 | 2018-07-19 | Telefonaktiebolaget Lm Ericsson (Publ) | A radio access node, a core network node, an information database and methods of operating the same in different radio access technologies |
US20190069229A1 (en) * | 2017-08-25 | 2019-02-28 | Qualcomm Incorporated | Techniques and apparatuses for search, measurement, and icon display in new radio non-standalone mode |
Non-Patent Citations (1)
Title |
---|
ERICSSON: "Handling RAT priorities in low frequency NR deployment scenarios", 3GPP DRAFT; R2-1812279 HANDLING RAT PRIORITIES IN LOW FREQ NR DEPLOYMENT SCENARIOS, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, vol. RAN WG2, no. Gothenburg, Sweden; 20180820 - 20180824, 10 August 2018 (2018-08-10), Mobile Competence Centre ; 650, route des Lucioles ; F-06921 Sophia-Antipolis Cedex ; France , XP051521886 * |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11533144B2 (en) | Indication of time-frequency synchronization signal block (SSB) locations of neighboring transmission-reception points for positioning reference signal puncturing purposes | |
EP4038801A1 (en) | Sounding reference signal (srs) configurations for one or more frequency hops | |
WO2021154373A1 (en) | Downlink control information (dci)-based triggered positioning reference signals (prs) | |
WO2022016495A1 (en) | Cell (re)selection and sidelink relay (re)selection procedures | |
WO2021223058A1 (en) | Selecting dual connectivity cell | |
WO2022126305A1 (en) | Tearing down a packet data session after a transition to a different subscription of a dual subscriber identity module dual standby user equipment | |
US11632725B2 (en) | Selective transmission of power headroom reports | |
WO2022047610A1 (en) | Secondary cell group in dormant state with data traffic disabled | |
US20230318681A1 (en) | Beam management for a secondary cell group in a dormant state | |
WO2021232226A1 (en) | Modifying a beam failure threshold based upon user equipment movement information | |
US20230058532A1 (en) | Complementary timing information for positioning reference signals for non-terrestrial networks | |
WO2021223057A1 (en) | Selecting dual connectivity cell | |
US11711772B2 (en) | Power control scheme for active bandwidth part transition | |
WO2022027554A1 (en) | Aperiodic measurements for a secondary cell group in a dormant state | |
WO2022056778A1 (en) | Cell reselection procedure based on locally determined value for omitted system information block parameter | |
US11895668B2 (en) | Uplink power change capability indication | |
WO2021243511A1 (en) | Identifier for runtime client application with network slice association | |
US11832271B2 (en) | Transmission configuration indicator state for aperiodic channel state information reference signal | |
US11812439B2 (en) | Rescheduling in integrated access fronthaul networks | |
WO2021223076A1 (en) | Optimizing physical downlink control channel (pdcch) power | |
WO2022193115A1 (en) | Puncturing of inter-frequency measurements during evolved packet system fallback call procedure | |
WO2021164008A1 (en) | Dci-guided pdcch dmrs reception bundling | |
US20230413185A1 (en) | Determining an initial prach preamble transmission power based on historical completed prach procedures | |
US20220015119A1 (en) | Timers and uplink skipping |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 20934299 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 20934299 Country of ref document: EP Kind code of ref document: A1 |