CN117044292A - Inter-cell mobility based on L1L 2 - Google Patents

Abstract

A User Equipment (UE) or other network device having a base station (e.g., a next generation node B) is operable to configure layer 1 (L1)/layer 2 (L2) -centric inter-cell mobility in a handover operation to improve latency and efficiency. Candidate cell configurations corresponding to different candidate cells for layer 1 (L1)/layer 2 (L2) -centric inter-cell mobility, as well as network indication/network conditions, may be transmitted via a first L1 communication, a first L2 communication, or an inter-L1 cell dynamic scheduling Downlink Control Information (DCI). Thus, in response to meeting a threshold associated with the network indication or the network condition, the UE may trigger the cell change of the L1/L2 centric inter-cell mobility to the target cell.

Description

Inter-cell mobility based on L1L 2

Technical Field

The present disclosure relates to wireless technology, including L1L 2-based inter-cell mobility in new air interface (NR) communications.

Background

Mobile communications in the next generation wireless communication system 5G or new air interface (NR) network will provide ubiquitous connectivity and access to information and the ability to share data throughout the world. The 5G network and network slices will be a unified, service-based framework that will target meeting common and time-to-time conflicting performance standards and provide services to a wide variety of application domains ranging from enhanced mobile broadband (eMBB) to large-scale machine type communications (emtc), ultra-reliable low-latency communications (URLLC), and other communications. Generally, NR will evolve based on third generation partnership project (3 GPP) Long Term Evolution (LTE) advanced technology and additional enhanced Radio Access Technologies (RATs) to achieve a seamless and faster wireless connection solution.

In a new air interface (NR) 5G network, load balancing is achieved through a handover operation, a redirection mechanism upon release of Radio Resource Control (RRC) signaling, and through the use of inter-frequency and Radio Access Technology (RAT) priority and offset parameters. However, layer 3 (L3) signaling at the network layer such as RRC signaling includes long handover delays, long interruption times during handover, and large signaling overhead. Therefore, the L3 handover mechanism does not always meet the goal of making high frequency fast cell changes in 5G networks. Thus, there is a need to enhance the signaling mechanism for handover to improve handover delay and efficiency by increasing the use of dynamic control signaling.

Drawings

Fig. 1 is a block diagram illustrating an example of a User Equipment (UE) that can be used in connection with various embodiments (aspects) described herein that is communicatively coupled with a network component as a peer device via a network.

Fig. 2 illustrates a control plane protocol stack that may be implemented for operation of the various embodiments and aspects described herein.

Fig. 3 is an exemplary simplified block diagram of a User Equipment (UE) wireless communication device or other network device/component (e.g., eNB, gNB) in accordance with various aspects.

Fig. 4 is a conditional handoff signaling flow for layer 1 (L1)/layer 2 (L2) centric inter-cell mobility that may be used at least in part or in whole in a handoff operation in accordance with various aspects.

Fig. 5 is a block diagram illustrating an exemplary process flow for layer 1 (L1)/layer 2 (L2) -centric inter-cell mobility in a handover operation in accordance with various aspects.

Fig. 6 is another block diagram illustrating an exemplary process flow for layer 1 (L1)/layer 2 (L2) -centric inter-cell mobility in a handover operation in accordance with various aspects.

Fig. 7 is another block diagram illustrating an exemplary signaling flow for layer 1 (L1)/layer 2 (L2) -centric inter-cell mobility in a handover operation in accordance with various aspects.

Fig. 8 is another block diagram illustrating an exemplary process flow according to various embodiments described herein.

Detailed Description

It is well known that the use of personally identifiable information should follow privacy policies and practices that are recognized as meeting or exceeding industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of authorized use should be specified to the user.

The present disclosure will now be described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout, and wherein the illustrated structures and devices are not necessarily drawn to scale. As used herein, the terms "component," "system," "interface," and the like are intended to refer to a computer-related entity, hardware, software (e.g., in execution), and/or firmware. For example, a component can be a processor (e.g., a microprocessor, a controller, or other processing device), a process running on a processor, a controller, an object, an executable, a program, a storage device, a computer, a tablet, and/or user equipment with a processing device (e.g., a mobile phone, etc.). By way of example, applications running on a server and the server may also be components. One or more components may reside within a process and a component may be localized on one computer and/or distributed between two or more computers. A set of elements or other collection of components may be described herein, wherein the term "set" may be interpreted as "one or more".

Furthermore, these components can execute from various computer readable storage media having various data structures stored thereon, such as using modules. The components may communicate via local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the internet, a local area network, a wide area network, or similar network with other systems via the signal).

As another example, a component may be an apparatus having particular functionality provided by a mechanical component that is operated by electrical or electronic circuitry that may be operated by a software application or a firmware application executed by one or more processors. The one or more processors may be internal or external to the device and may execute at least a portion of the software or firmware application. For another example, the component may be a device that provides a specific function through an electronic component without a mechanical component; the electronic component may include one or more processors therein to execute software and/or firmware that at least partially imparts functionality to the electronic component.

The use of the term "exemplary" is intended to present concepts in a concrete fashion. As used in this disclosure, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise or clear from context, "X employs A or B" is intended to mean any of the natural inclusive permutations. That is, if X employs A; x is B; or X employs both A and B, then "X employs A or B" is satisfied in any of the foregoing cases. In addition, the articles "a" and "an" as used in this disclosure and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Furthermore, to the extent that the terms "includes," including, "" has, "" with, "or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term" comprising. Further, where one or more numbered items (e.g., "first X," "second X," etc.) are discussed, typically the one or more numbered items may be different or they may be the same, but in some cases the context may indicate that they are different or that they are the same.

As used herein, the term "circuitry" may refer to or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), or associated memory (shared, dedicated, or group) that is operatively coupled to circuits that execute one or more software or firmware programs, a combinational logic circuit, or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in or the functionality associated with one or more software or firmware modules. In some embodiments, the circuitry may comprise logic that is at least partially operable in hardware.

In view of various concerns about enhancement of signaling mechanisms for handover to improve handover delay and efficiency by increasing the use of dynamic control signaling (as opposed to RRC signaling), mechanisms for layer 1 (L1)/layer 2 (L2) -centric inter-cell mobility in handover operations have been proposed. The goal of L1/L2 centric inter-cell mobility is high frequency fast cell change. Current conventional layer 3 (L3) handover mechanisms have difficulty achieving this for several different reasons. For example, L3 handover has a long handover delay, a long interruption time during handover, and incurs heavy signaling overhead.

In aspects, lower latency and lower overhead handovers may be configured in a next generation (NR) network or a 5G core network by supporting inter-cell handovers centered at L1/L2. This may enable multiple cell candidate configurations and Transmission Control Indication (TCI) states to be stored and autonomously dynamically used for handover by a User Equipment (UE) device while reducing delay and signaling load.

In one aspect, a network (e.g., a base station, evolved node B (eNB), next generation node B (gNB), or other network component) may configure a plurality of candidate cells to a UE before a handover operation is required. In response to a predetermined condition or network indication, the UE may store candidate cell configurations to be applied later. The UE may maintain the stored set of candidate cell configurations in order to perform cell changes back to the initial serving cell configuration or to a subsequent candidate cell configuration that is different from the previous cell configuration. Later, the UE may select a candidate cell from the set of candidate cell configurations as the target cell and perform beam selection to the target cell.

In one example, the UE may perform cell change according to network indication or network conditions based on layer 1 (L1) or layer 2 (L2) communications/signaling, such as L1 and L2 messages (as layer 3 (L3) messages/communications) that are not necessarily visible to the Radio Resource Control (RRC) layer. The network conditions may be based on conditional handoff conditions (e.g., A3 or A5 events). The network conditions or network indications may be transmitted by a base station or a gNB and received via at least one of L1 communications, L2 communications, or L1 inter-cell dynamic scheduling Downlink Control Information (DCI). In response to meeting a threshold associated with the network indication or with the network condition, the UE may then perform or trigger a cell change to one of the candidate cells for L1/L2-centric inter-cell mobility in the handover operation.

Other aspects and details of the disclosure are described further below with respect to the drawings.

Fig. 1 illustrates an exemplary architecture of a system 100 of a network in accordance with various embodiments (aspects). The following description is provided for an exemplary system 100 capable of combining the LTE system standard and the 5G or NR system standard provided by the 3GPP technical specifications. However, the example embodiments are not limited in this regard and the embodiments may be applied to other networks that benefit from the principles described herein, such as future 3GPP systems (e.g., sixth generation (6G)) systems, IEEE 802.16 protocols (e.g., WMAN, wiMAX, etc.), and the like.

As shown in fig. 1, the system 100 includes a UE 101a and a UE 101b (collectively, "UE 101"). In this example, the UE 101 is shown as a smart phone (e.g., a handheld touch screen mobile computing device connectable to one or more cellular networks), but may include any mobile or non-mobile computing device, such as consumer electronics devices, cellular phones, smart phones, feature phones, tablet computers, wearable computer devices, personal Digital Assistants (PDAs), pagers, wireless handheld devices, desktop computers, laptop computers, in-vehicle infotainment (IVI), in-vehicle entertainment (ICE) devices, dashboards (ICs), heads-up display (HUD) devices, in-vehicle diagnostic (OBD) devices, dashtop Mobile Equipment (DME), mobile Data Terminals (MDT), electronic Engine Management Systems (EEMS), electronic/Engine Control Units (ECU), electronic/engine Electronic Control Modules (ECM), embedded systems, microcontrollers, control modules, engine Management Systems (EMS), networking or "smart" appliances, machine-type communication (MTC) devices, machine-to-machine (M2M) devices, internet of things (IoT) devices, and the like.

In some embodiments, any of the UEs 101 may be IoT UEs that may include a network access layer designed for low power IoT applications that utilize short-term UE connections. IoT UEs may utilize technologies such as M2M or MTC to exchange data with MTC servers or devices via Public Land Mobile Networks (PLMNs), proximity services (ProSe), or device-to-device (D2D) communications, sensor networks, or IoT networks. The M2M or MTC data exchange may be a machine-initiated data exchange. IoT networks describe interconnected IoT UEs that may include uniquely identifiable embedded computing devices (within the internet infrastructure) with ephemeral connections. The IoT UE may execute a background application (e.g., keep-alive messages, status updates, etc.) to facilitate connection of the IoT network.

The UE 101 may be configured to connect (e.g., communicatively couple) with a Radio Access Network (RAN) 110. In an embodiment, RAN 110 may be a Next Generation (NG) RAN or a 5GRAN, an evolved-UMTS terrestrial RAN (E-UTRAN), or a legacy RAN, such as UTRAN or GERAN. As used herein, the term "NG RAN" or the like may refer to RAN 110 operating in NR or 5G system 100, while the term "E-UTRAN" or the like may refer to RAN 110 operating in LTE or 4G system 100. The UE 101 utilizes connections (or channels) 102 and 104, respectively, each of which includes a physical communication interface/layer.

Alternatively or in addition, each of the UEs 101 may be configured with Dual Connectivity (DC) as multi-RAT or multi-radio dual connectivity (MR-DC), where a multi-Rx/Tx capable UE may be configured to utilize resources provided by two different nodes (e.g., 111, 112 or other network nodes) capable of via non-ideal backhaul connections, e.g., one of the nodes providing NR access and the other node providing E-UTRA for LTE or NR access for 5G. One node may act as a Master Node (MN) and the other node may act as a Secondary Node (SN). The MN and SN may be connected via a network interface and at least the MN is connected to the core network 120. At least one of the MN and/or SN can be operated with shared spectrum channel access. All functions specified for the UE are available for integrated access and backhaul mobile terminals (IAB-MT). Similar to the UE 101, the IAB-MT may access the network using one network node or using two different nodes with EN-DC architecture, NR-DC architecture, etc.

In MR-DC, a set of serving cells associated with a primary node may be configured as a primary cell group (MCG), including a special cell (SpCell) as a primary cell (PCell) and optionally one or more secondary cells (scells). The MCG may be a radio access node providing a control plane connection to a Core Network (CN) 120; it may be, for example, a master eNB (in EN-DC), a master ng-eNB (in NGEN-DC) or a master gNB (in NR-DC and NE-DC). SpCell may refer to PCell of MCG or PSCell of a Second Cell Group (SCG), depending on whether a MAC entity is associated with MCG or SCG, respectively. SpCell may refer to the PCell of MCG or SCG. The SCG in the MR-DC may be a set of serving cells associated with the SN, consisting of a SpCell as primary secondary cell (PSCell) and optionally one or more scells.

In this example, connection 102 and connection 104 are shown as air interfaces to enable communicative coupling, and may be consistent with cellular communication protocols, such as global system for mobile communications (GSM) protocols, code Division Multiple Access (CDMA) network protocols, push-to-talk (PTT) protocols, push-to-talk (POC) protocols, universal Mobile Telecommunications Service (UMTS) protocols, 3GPP LTE protocols, 5G protocols, NR protocols, and/or any of the other communication protocols discussed herein. In an embodiment, the UE 101 may exchange communication data directly via the ProSe interface 105. ProSe interface 105 may alternatively be referred to as SL interface 105 and may include one or more logical channels including, but not limited to, a physical side link control channel (PSCCH), a physical side link shared channel (PSSCH), a physical side link discovery channel (PSDCH), and a physical side link broadcast channel (PSBCH).

UE 101b is shown configured to access an AP 106 (also referred to as "WLAN node 106", "WLAN terminal 106", "WT 106", etc.) via connection 107. Connection 107 may comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, where AP 106 would comprise wireless fidelityAnd a router. In this example, the AP 106 is shown connected to the internet without being connected to the core network of the wireless system (described in further detail below). In various embodiments, the UE 101b, RAN 110, and AP 106 may be configured to utilize LTE-WLAN aggregation (LWA) operation and/or LTE/WLAN radio level operation integrated with IPsec tunneling (LWIP). The LWA operation may involve configuring, by the RAN nodes 111a-111b, the UE 101b in a radio resource control rrc_connected state to utilize radio resources of LTE and WLAN. LWIP operations may involve the UE 101b using WLAN radio resources (e.g., connection 107) to authenticate and encrypt packets (e.g., IP packets) sent over connection 107 via an IPsec protocol tunnel. IPsec tunneling may include encapsulating the entire original IP packet and And adds a new packet header, protecting the original header of the IP packet.

RAN 110 includes one or more access AN nodes or RAN nodes 111a and 111b (collectively, "RAN nodes 111") that enable connections 102 and 104. As used herein, the terms "access node," "access point," and the like may describe equipment that provides radio baseband functionality for data and/or voice connections between a network and one or more users. These access nodes may be referred to as BS, gNB, RAN nodes, enbs, nodes B, RSU, transmission reception points (TRxP) or TRP, etc., and may include ground stations (e.g., terrestrial access points) or satellite stations that provide coverage within a geographic area (e.g., cell). As used herein, the term "NG RAN node" or the like may refer to a RAN node 111 (e.g., a gNB) operating in an NR or 5G system 100, while the term "E-UTRAN node" or the like may refer to a RAN node 111 (e.g., a next generation node B (gNB)) operating in an LTE or 5G system 100. According to various embodiments, RAN node 111 may be implemented as one or more of a dedicated physical device such as a macrocell base station and/or a Low Power (LP) base station for providing a femtocell, picocell, or other similar cell with a smaller coverage area, smaller user capacity, or higher bandwidth than a macrocell.

In some embodiments, all or part of RAN node 111 may be implemented as one or more software entities running on a server computer as part of a virtual network that may be referred to as a Centralized RAN (CRAN) and/or a virtual baseband unit pool (vbup). In these embodiments, the CRAN or vBBUP may implement RAN functional splits, such as Packet Data Convergence Protocol (PDCP) splits, with the Radio Resource Control (RRC) layer and PDCP layer operated by the CRAN/vBBUP and other L2 protocol entities operated by the respective RAN nodes 111; medium Access Control (MAC)/Physical (PHY) layer split, wherein the RRC layer, PDCP layer, RLC layer, and MAC layer are operated by CRAN/vbup, and the PHY layer is operated by each RAN node 111; or "lower PHY" split, where the upper parts of the RRC layer, PDCP layer, RLC layer, MAC layer, and PHY layer are operated by CRAN/vBBUP, and the lower parts of the PHY layer are operated by the respective RAN nodes 111. The virtualization framework allows idle processor cores of the plurality of RAN nodes 111 to execute other virtualized applications.

In some implementations, a separate RAN node 111 may represent each gNB Distributed Unit (DU) connected to a gNB Central Unit (CU) via each F1 interface. In these implementations, the gNB-DU may include one or more remote radio headers or RF Front End Modules (RFEM) (not shown), and the gNB-CU may be operated by a server (not shown) located in RAN 110 or by a server pool in a similar manner as CRAN/vbBup. Additionally or alternatively, one or more of the plurality of RAN nodes 111 may be a next generation eNB (NG-gNB) that is a RAN node providing E-UTRA user plane and control plane protocol terminals to the UE 101 and connected to the 5GC via an NG interface.

Any of the RAN nodes 111 may be the end point of the air interface protocol and may be the first point of contact for the UE 101. In some embodiments, any of RAN nodes 111 may perform various logical functions of RAN 110 including, but not limited to, functions of a Radio Network Controller (RNC), such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management.

In an embodiment, UE 101 may be configured to communicate with each other or any of RAN nodes 111 over a multicarrier communication channel using Orthogonal Frequency Division Multiplexing (OFDM) communication signals in accordance with various communication techniques such as, but not limited to, OFDMA communication techniques (e.g., for downlink communication) or single carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or side-link communication), although the scope of the embodiments is not limited in this respect. The OFDM signal may comprise a plurality of orthogonal subcarriers.

In some embodiments, the downlink resource grid may be used for downlink transmissions from any of the RAN nodes 111 to the UE 101, while uplink transmissions may utilize similar techniques. The grid may be a time-frequency grid, referred to as a resource grid or time-frequency resource grid, which is a physical resource in the downlink in each time slot. For OFDM systems, such time-frequency plane representation is common practice, which makes radio resource allocation intuitive. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in the radio frame. The smallest time-frequency unit in the resource grid is denoted as a resource element. Each resource grid includes a plurality of resource blocks that describe the mapping of certain physical channels to resource elements. Each resource block includes a set of resource elements; in the frequency domain, this may represent the minimum amount of resources that can be currently allocated. Several different physical downlink channels are transmitted using such resource blocks.

According to various embodiments, the UE 101 and the RAN node 111 transmit data (e.g., transmit data and receive data) over a licensed medium (also referred to as a "licensed spectrum" and/or "licensed band") and an unlicensed shared medium (also referred to as an "unlicensed spectrum" and/or "unlicensed band"). The licensed spectrum may include channels operating in a frequency range of about 400MHz to about 3.8GHz, while the unlicensed spectrum may include the 5GHz band.

PDSCH carries user data and higher layer signaling to multiple UEs 101. The Physical Downlink Control Channel (PDCCH) carries information on transport formats and resource allocations related to the PDSCH channel, and so on. It may also inform the UE 101 about transport format, resource allocation and hybrid automatic repeat request (HARQ) information related to the uplink shared channel. In general, downlink scheduling (allocation of control and shared channel resource blocks to UEs 101b within a cell) may be performed at any one of the RAN nodes 111 based on channel quality information fed back from any one of the UEs 101. The downlink resource allocation information may be sent on a PDCCH for (e.g., allocated to) each of the UEs 101.

The PDCCH transmits control information using Control Channel Elements (CCEs). The PDCCH complex-valued symbols may first be organized into quadruples before being mapped to resource elements, and then may be aligned for rate matching using a sub-block interleaver. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements, respectively, referred to as REGs. Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. Depending on the size of the DCI and the channel conditions, the PDCCH may be transmitted using one or more CCEs. There may be four or more different PDCCH formats with different numbers of CCEs (e.g., aggregation level, l=1, 2, 4, 8, 16) defined in LTE.

In aspects where system 100 is a 5G or NR system, interface 112 may be an Xn interface 112. An Xn interface is defined between two or more RAN nodes 111 (e.g., two or more gnbs, etc.) connected to the 5gc 120, between a RAN node 111 (e.g., a gNB) connected to the 5gc 120 and an eNB, and/or between two enbs connected to the 5gc 120. In some implementations, the Xn interface can include an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface. Xn-U may provide non-guaranteed delivery of user plane PDUs and support/provide data forwarding and flow control functions. An Xn-C may provide management and error handling functions for managing the functions of the Xn-C interface; mobility support for UEs 101 in CONNECTED mode (e.g., CM-CONNECTED) includes functionality for managing UE mobility in CONNECTED mode between one or more RAN nodes 111. Mobility support may include context transfer from the old (source) serving RAN node 111 to the new (target) serving RAN node 111, as well as control of user plane tunnels between the old (source) serving RAN node 111 and the new (target) serving RAN node 111. The protocol stack of an Xn-U may include a transport network layer built on top of an Internet Protocol (IP) transport layer and a user plane GPRS tunneling protocol (GTP-U) layer on top of the User Datagram Protocol (UDP) and/or IP layer for carrying user plane PDUs. The Xn-C protocol stack may include an application layer signaling protocol, referred to as the Xn application protocol (Xn-AP), and a transport network layer built on top of the Stream Control Transmission Protocol (SCTP). SCTP may be on top of the IP layer and may provide guaranteed delivery of application layer messages. In the transport IP layer, signaling PDUs are delivered using point-to-point transport. In other implementations, the Xn-U protocol stack and/or the Xn-C protocol stack may be the same or similar to the user plane and/or control plane protocol stacks shown and described herein.

RAN 110 is shown communicatively coupled to a core network-in this embodiment, to a Core Network (CN) 120.CN 120 may include a plurality of network elements 122 configured to provide various data and telecommunications services to clients/subscribers (e.g., users of UE 101) connected to CN 120 via RAN 110. The components of the CN 120 may be implemented in one physical node or in separate physical nodes including components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). In some embodiments, NFV may be used to virtualize any or all of the above-described network node functions via executable instructions stored in one or more computer-readable storage media (described in further detail below). The logical instance of the CN 120 may be referred to as a network slice, and the logical instance of a portion of the CN 120 may be referred to as a network sub-slice. Network Function Virtualization (NFV) architecture and infrastructure may be used to virtualize one or more network functions onto physical resources (alternatively performed by proprietary hardware) that include industry standard server hardware, storage hardware, or a combination of switches. In other words, NFV systems may be used to perform virtual or reconfigurable implementations of one or more Evolved Packet Core (EPC) components/functions.

In general, the application server 130 may be an element (e.g., universal mobile telecommunications system packet service (UMTS PS) domain, LTE PS data service, etc.) that provides an application program that uses IP bearer resources with the core network. The application server 130 may also be configured to support one or more communication services (e.g., voIP session, PTT session, group communication session, social networking service, etc.) for the UE 101 via the EPC 120.

In aspects, CN 120 may be a 5GC (referred to as "5GC 120" or the like), and RAN 110 may be connected with CN 120 via NG interface 112. In an embodiment, NG interface 112 may be split into two parts: a Next Generation (NG) user plane (NG-U) interface 114 that carries traffic data between RAN node 111 and a User Plane Function (UPF); and an S1 control plane (NG-C) interface 115, which is a signaling interface between RAN node 111 and an access and mobility management function (AMF).

In the case where CN 120 is EPC (referred to as "EPC 120", etc.), RAN 110 may be connected with CN 120 via S1 interface 112. In an embodiment, the S1 interface 112 may be split into two parts: an S1 user plane (S1-U) interface 114 that carries traffic data between RAN node 111 and the S-GW; and an S1-MME interface 115, which is a signaling interface between RAN node 111 and MME.

The core NW element/component 122 may include one or more of the following functions and network components: an authentication server function (AUSF); access and mobility management functions (AMFs); session Management Function (SMF); a Network Exposure Function (NEF); policy Control Function (PCF); network Repository Function (NRF); unified Data Management (UDM); an Application Function (AF); a User Plane (UP) function (UPF); and a Network Slice Selection Function (NSSF).

For example, the UPF may serve as an anchor point for intra-RAT and inter-RAT mobility, an external Protocol Data Unit (PDU) session point interconnected with a Data Network (DN), and a branching point to support multi-homed PDU sessions. The UPF may also perform packet routing and forwarding, perform packet inspection, perform policy rules user plane part, lawful intercept packets (UP collection), perform traffic usage reporting, perform QoS processing on the user plane (e.g., packet filtering, gating, uplink (UL)/Downlink (DL) rate execution), perform uplink traffic verification (e.g., service Data Flow (SDF) to QoS flow mapping), transmit level packet marking in the uplink and downlink, and perform downlink packet buffering and downlink data notification triggering. The UPF may include an uplink classifier for supporting routing traffic to the data network. The DN may be various network operator services, internet access, or third party services, including or similar to an application server. The UPF may interact with the SMF via an N4 reference point between the SMF and the UPF.

For example, the AUSF may store data for authentication of the UE 101 and process authentication related functions. The AUSF may facilitate a common authentication framework for various access types. The AUSF may communicate with the AMF via an N12 reference point between the AMF and the AUSF; and may communicate with the UDM via an N13 reference point between the UDM and the AUSF. In addition, the AUSF may present an interface based on the Nausf service.

For example, the AMF may be responsible for registration management (e.g., for registering the UE 101, etc.), connection management, reachability management, mobility management, and lawful interception of AMF related events, and access authentication and authorization. The AMF may be the termination point of the N11 reference point between the AMF and the SMF. The AMF may provide transport for SM messages between UE 110 and the SMF and act as a transparent proxy for routing SM messages. The AMF may also provide for transmission of Short Message Service (SMS) messages between the UE 101 and an SMSF function (SMSF). The AMF may act as a security anchoring function (SEAF), which may include interaction with the AUSF and the UE 101 and/or receiving intermediate keys established as a result of the UE 10 authentication procedure. In the case of using Universal Subscriber Identity Module (USIM) based authentication, the AMF may retrieve the security material from the AUSF. The AMF may also include a Single Connectivity Mode (SCM) function that receives a key from the SEA for deriving an access network specific key. Furthermore, the AMF may be AN endpoint of a RAN Control Plane (CP) interface, which may include or be AN N2 reference point between the (R) AN 110 and the AMF; and AMF is the termination point for Non Access Stratum (NAS) (N1) signaling and performs NAS ciphering and integrity protection.

The AMF may also support NAS signaling with the UE 101 over a non-3 GPP (N3) interworking function (IWF) interface. The N3IWF may be used to provide access to untrusted entities. The N3IWF may be the termination point of the N2 interface of the control plane (R) AN 110 and the AMF and may be the termination point of the N3 reference point between the user plane (R) AN 101 and the UPF. Thus, the AMF may process N2 signaling from the SMF and AMF for PDU sessions and QoS, encapsulate/decapsulate packets for Internet Protocol (IP) security (IPSec) and N3 tunnels, label N3 user plane packets in the uplink, and perform QoS corresponding to the N3 packet labels, thereby taking into account QoS requirements associated with such labels received over N2. The N3IWF may also relay uplink and downlink control plane NAS signaling between the UE 101 and the AMF via the N1 reference point between the UE 101 and the AMF, and relay uplink and downlink user plane packets between the UE 101 and the UPF. The N3IWF also provides a mechanism for establishing an IPsec tunnel with the UE 101. The AMFs may present an interface based on Namf services and may be an end point of an N14 reference point between two AMFs and an N17 reference point with a 5G equipment identity register (5G-EIR) (not shown in fig. 1).

The UE 101 may register with the AMF to receive network services. Registration Management (RM) is used to register or de-register a UE 101 with a network (e.g., AMF) and establish a UE context in the network (e.g., AMF). The UE 101 may operate in the RM-REGISTRED state or the RM-DEREGISTRED state. In the RM-registered state, the UE 101 is not registered with the network, and the UE context in the AMF does not hold valid location or routing information of the UE 101, so the AMF cannot reach the UE 101. In the RM-REGISTERED state, the UE 101 registers with the network and UE context in the AMF may maintain valid location or routing information for the UE 101 so the AMF can reach the UE 101. In the RM-REGISTERED state, the UE 101 may perform a mobility registration update procedure, perform a periodic registration update procedure triggered by expiration of a periodic update timer (e.g., notify the network that the UE 101 is still active), and perform a registration update procedure to update UE capability information or renegotiate protocol parameters with the network, etc.

The AMF may store one or more RM contexts for the UE 101, where each RM context is associated with a particular access to the network. The RM context may be a data structure, database object, etc., which indicates or stores, among other things, the registration status and periodic update timer for each access type. The AMF may also store a 5GC Mobility Management (MM) context that is the same as or similar to the (enhanced packet system (EPS)) MM ((E) MM) context. In various embodiments, the AMF may store Coverage Enhancement (CE) mode B restriction parameters for the UE 101 in an associated MM context or RM context. The AMF may also derive values from the usage setting parameters of the UE that have been stored in the UE context (and/or MM/RM context) when needed.

Fig. 2 is an illustration of a control plane protocol stack in accordance with various aspects described herein. In this embodiment, the control plane 200 is shown as a communication protocol stack between the UE 101, RAN node 111 and AMF 121, SMF 123 or Mobility Management Entity (MME).

The PHY layer 201 may transmit or receive information used by the MAC layer 202 over one or more air interfaces. PHY layer 201 may also perform link adaptation or Adaptive Modulation and Coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers, such as RRC layer 205. PHY layer 201 may still perform: error detection for a transmission channel, forward Error Correction (FEC) encoding/decoding of a transmission channel, modulation/demodulation of a physical channel, interleaving, rate matching, mapping to a physical channel, and multiple-input multiple-output (MIMO) antenna processing.

The MAC layer 202 may perform: mapping between logical channels and transport channels, multiplexing MAC Service Data Units (SDUs) from one or more logical channels onto Transport Blocks (TBs) to be delivered to a PHY via a transport channel, demultiplexing MAC SDUs from Transport Blocks (TBs) delivered from a PHY via a transport channel onto one or more logical channels, multiplexing MAC SDUs onto TBs, scheduling information reporting, error correction by hybrid automatic repeat request (HARQ), and logical channel prioritization.

The RLC layer 203 may operate in a variety of modes of operation including: transparent Mode (TM), unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC layer 203 may perform transmission of upper layer Protocol Data Units (PDUs), error correction by automatic repeat request (ARQ) for AM data transmission, and concatenation, segmentation and reassembly of RLC SDUs for UM and AM data transmission. The RLC layer 203 may also perform re-segmentation on RLC data PDUs for AM data transmissions, re-ordering RLC data PDUs for UM and AM data transmissions, detecting duplicate data for UM and AM data transmissions, discarding RLC SDUs for UM and AM data transmissions, detecting protocol errors for AM data transmissions, and performing RLC re-establishment.

The PDCP layer 204 may perform header compression and decompression of IP data, maintain PDCP Sequence Numbers (SNs), perform sequential delivery of upper layer PDUs upon lower layer re-establishment, eliminate duplication of lower layer SDUs upon re-establishment of lower layers for radio bearers mapped on RLC AM, encrypt and decrypt control plane data, perform integrity protection and integrity verification on control plane data, control timer-based data discard, and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.).

The primary services and functions of the RRC layer 205 may include broadcasting of system information (e.g., included in a Master Information Block (MIB) or a System Information Block (SIB) related to a non-access stratum (NAS)), broadcasting of system information related to an Access Stratum (AS), paging, establishment, maintenance and release of RRC connections between UEs and E-UTRAN (e.g., RRC connection paging, RRC connection establishment, RRC connection modification and RRC connection release), establishment, configuration, maintenance and release of point-to-point radio bearers, security functions including key management, mobility between Radio Access Technologies (RATs) and measurement configuration for UE measurement reporting. The MIB and SIB may include one or more information elements (TEs), each of which may include a separate data field or data structure.

The UE 101 and the RAN node 111 may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange control plane data via a protocol stack including a PHY layer 201 (e.g., layer 1 (L1)), a MAC layer 202 (e.g., layer 2 (L2)), an RLC layer 203, a PDCP layer 204, and an RRC layer 205 (e.g., layer 3 (L3)).

The non-access stratum (NAS) protocol 206 forms the highest layer of the control plane between the UE 101 and the MME 121. The NAS protocol 206 supports mobility and session management procedures for the UE 101 to establish and maintain IP connections between the UE 101 and the P-GW or AMF.

The S1 application protocol (S1-AP) layer 215 may support the functionality of the S1 interface and include basic procedures (EPs). An EP is an interworking unit between the RAN node 111 and the CN 120. The S1-AP layer service may include two groups: UE-associated services and non-UE-associated services. The functions performed by these services include, but are not limited to: E-UTRAN radio access bearer (E-RAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM), and configuration transport.

A Stream Control Transmission Protocol (SCTP) layer (also referred to as SCTP/IP layer) 214 may ensure reliable delivery of signaling messages between RAN node 111 and MME 121 based in part on the IP protocols supported by IP layer 213. The L2/N2 layer 212 and the L1/N1 layer 211 may refer to the communication links (e.g., wired or wireless) used by the RAN node and the AMF, SMF, or MME to exchange information. For example, the MME or AMF of RAN node 111 and network component 1222 may utilize interfaces to exchange control plane data via a protocol stack including L1/N1 layer 211, L2/N2 layer 212, IP layer 213, SCTP layer 214, and S1-AP layer 215.

Referring to fig. 3, a block diagram of a User Equipment (UE) device or other network device/component (e.g., a gNB, eNB, or other participating network entity/component) is shown. The UE device 300 includes: one or more processors 310 (e.g., one or more baseband processors) that include processing circuitry and associated interfaces; transceiver circuitry 320 (e.g., comprising RF circuitry, which may include transmitter circuitry (e.g., associated with one or more transmit chains) and/or receiver circuitry (e.g., associated with one or more receive chains), which may employ common circuit elements, different circuit elements, or a combination thereof); and memory 310 (which may comprise any of a variety of storage media and may store instructions and/or data associated with one or more of processor 310 or transceiver circuitry 320).

Memory 330 (as well as other memory components discussed herein, e.g., memory, data storage, etc.) may include one or more machine-readable media containing instructions that, when executed by a machine or component herein, cause the machine or other device to perform the actions of a method or apparatus or system for communicating using a variety of communication techniques in accordance with aspects, embodiments, and examples described herein. It should be understood that the aspects described herein may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium, such as the memory or other storage devices described herein. 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. Storage media or computer-readable storage devices can be any available media that can be accessed by a general purpose or special purpose computer. By way of example only, and not limitation, such computer-readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or other tangible and/or non-transitory media, operable to carry or store desired information or executable instructions. Moreover, any connection may be termed a computer-readable medium.

In one aspect, the UE/gNB device 300 is operable to be configured by: physical layer transmissions comprising a plurality of different TBs are processed/generated/encoded/decoded based on unequal protection between different Transport Blocks (TBs) in a physical layer encapsulation (e.g., EPC packets, transmission opportunities, MCOTs, single transmission bursts, TTIs, or other encapsulation protocols or related encapsulation parameters for encapsulating data from a higher layer into frames for over-the-air transmission). The physical layer transmissions may be received, transmitted, or provided by communication/transmitter circuitry 320 to similarly process/generate physical layer transmissions having four or fewer spatial layers via physical channels in the NR network.

Processor 310 may be a component of an application circuit or a processor of a baseband circuit that may be used to execute elements of one or more instances of a protocol stack. For example, the processor 310 of the baseband circuitry may be used alone or in combination to perform layer 3, layer 2, or layer 1 functions, while the processor of the application circuitry may utilize data (e.g., packet data) received from these layers and further perform layer 4 functions (e.g., transmission Communication Protocol (TCP) and User Datagram Protocol (UDP) layers). As mentioned herein, layer 3 (L3) may include a Radio Resource Control (RRC) layer, which will be described in further detail below. As mentioned herein, layer 2 (L2) may include a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, and a Packet Data Convergence Protocol (PDCP) layer, which will be described in further detail below. As mentioned herein, layer 1 (L1) may include a Physical (PHY) layer of the UE/RAN node, as will be described in further detail below.

Referring to fig. 4, an exemplary conditional handoff process flow 400 between a UE, a source node, and a potential target node or cell is illustrated. The UE402, source node (e.g., the gNB 404), and potential target node 406 are communicatively coupled for wireless communication. The UE402 may be an example of any other UE (e.g., 101 or 300) that also includes similar components. Likewise, source node 404 and potential target node 406 may also be examples of base stations (such as gnbs 111a, 111b, or 300) that also include similar components.

The conditional handover process flow 400 is initiated at 408, where the source node or gNB 404 provides a conditional handover request to obtain candidate cell configurations for the neighboring potential target node 406. In turn, one or more target nodes 406 provide a Conditional Handover (CHO) request acknowledgement with RRC configuration, e.g., at 410. The gNB 404 then provides the CHO command to the UE402 in advance at 412. At 414, the UE monitors CHO conditions of the target cell based on the CHO command. If the condition is met, the UE402 performs or triggers a handover at 416. The random access procedure may then be configured by the UE402 to disengage from the source node 404 and synchronize with the target node 406 via UL synchronization 418 and DL synchronization 420. After the handover at 422 is successfully completed, resources in the source node 404 may be released. At 424, path switching and UE context release may occur, wherein the UE may release the CHO candidate's configuration after successful switching is completed.

Conditional handover operations may reduce the number of mobility-related failures. In conditional handover 400, for example, UE 402 receives the handover command and stores the command (rrcrecon configuration message 410 prepared by target candidate cell 406 in response to CHO request 408) rather than applying the command immediately or upon receipt as in conventional handover. Along with the command, the UE 402 also receives at 412 the associated conditions to be monitored at 414. When this condition is met, the mobile terminal applies the previously stored handover command at 416 as if the network had just sent the command, rather than first sending a measurement report (which may not be transmitted) and then waiting to receive the command (which may not be received).

The conditions defining the criteria for applying the stored handover command may be based on the quality of the serving cell and the neighboring cells, which is somewhat similar to the conditions in the previous version that led the UE 402 to transmit the measurement report when the conditions were met. For example, the network may configure the UE 402 to transmit measurement reports when the potential target node 406 (or neighboring cell) becomes a better offset than the source node 404 as a way to indicate to the network or source node 404 that a handover may be required. In conditional handover operation 400, similar conditions may be configured except that UE 402 does not transmit a measurement report, but rather applies the stored message. Sending the handover command while radio conditions are still favourable reduces the risk of measurement report transmission failure or handover command reception failure.

In one aspect, the HO conditions may again use, for example, measurement events A3 or A5, or other network conditions that may be based on Reference Signal Received Power (RSRP), reference Signal Received Quality (RSRQ), or other parameters for link quality metrics. The A3 event may be a condition that triggers when the serving cell 404 becomes worse than a preconfigured threshold for the L1 or L2 communication link. For example, the condition may include being triggered or satisfied when the L1/L2 measurement of the candidate cell is greater than or equal to a threshold for L1 or L2 link or L1/L2 evaluation. The measurement of the link may be within a time period or window or include an average of the measurements within the time period or window. The threshold may also be offset by a differential increment (e.g., 0 to 30dB, or other difference). Triggering may also be cancelled when the condition is not true for that period of time. For example, an A5 event may be a condition that triggers when the serving cell 504 becomes worse than a first threshold and the neighboring cell becomes better than a second threshold. For example, the network may also utilize or indicate other measurement events (e.g., any combination of measurement events A1-A5, etc.) for monitoring by the UE 402 at 414.

The assessed one or more link quality metrics may be measured over the L1, L2, or L3 communication link or connection based on various criteria including, but not limited to, RSRP, RSRQ, data estimation, subcarrier spacing (SCS), numerology, beam switching, beam failure, secondary Cell Group (SCG) failure, transmit power, uplink grant size, buffer Status Report (BSR) threshold, bandwidth part (BWP) switching, uplink or downlink Modulation Coding Scheme (MCS), block error rate (BLER), or Power Headroom Report (PHR). Each of these criteria may also include different weights as factors/weights in the LQM evaluation. The criteria for configuring the conditions may be based on or include one or more parameters (e.g., layer 1 or 2 parameters). Based on whether data estimation or data is given for the PSCell or other cell, a LQM assessment may be determined between UL and DL links, e.g., on a per RAT basis and on a per CC basis, respectively, in order to determine conditions.

In one aspect, network conditions, associated criteria for network conditions, associated weights/priorities for such criteria, or other network indications (beam indication, target cell selection, etc.) may be predefined, statically or dynamically configured via L1 communications, L2 communications, or L3 communications. For example, an Information Element (IE) or a configuration element of the IE may indicate parameters/weights for performing the evaluation on different links (e.g., L1/L2/L3) independently for different RATs, CCs, and bandwidth usage/direction (UL/DL).

The UE 402 may perform handover in the candidate cell configuration of the prepared cell based on the candidate cell configuration. In another aspect, the network or base station may communicate candidate cell configurations via L1 communications, L2 communications, L1 inter-cell dynamic scheduling DCI, or L3 communications. The network conditions or network indications may also be transmitted in the same or different L1 communications, L2 communications, L1 inter-cell dynamic scheduling DCI, or L3 communications.

In aspects, the UE 402 may be configured with two or more conditions or network indications that may be associated with the stored command, so the command may only be applied if the two or more conditions are met. Examples of network conditions or network indications may be similar to or different from the criteria that the network will define for handover based on multiple measurement reports triggered by multiple conditions. One example may be measurement reports for different types of measurement quantities, such as cell coverage as represented by Radio Signal Received Power (RSRP) and quality as represented by Radio Signal Received Quality (RSRQ). A larger value means that conditional handover is only performed when the neighboring cell is much better than the serving cell (based on a preconfigured differential delta or indicated amount/threshold), while a smaller value means that conditional handover will be performed if the neighboring cell is slightly better. A larger threshold may increase the chance of failure because the UE 402 may fail before finding a much better neighbor.

On the network side, the serving/source node 404 may configure one or more target "candidate" cells 406 because it may not be completely determined whether the UE 402 will access a particular target cell. The conditional handover preparation procedure has some similarities to the handover preparation procedure and the result may be to create a handover command (e.g., rrcrecon configuration message 410 containing the configuration of the target, or L1 message or L2 message), but the target node 406 does not expect the UE 402 to access the command immediately, if any.

In other aspects, the handover command may include one or more of the following: candidate cell configuration, network conditions for monitoring L1/L2/L3 links for L1/L2 centric inter-cell mobility, an indication of a limit for L1/L2 based cell change mobility, or L1/L2/L3 configured cells for a group of cells. For example, the set of cells may be connected via an ideal backhaul.

The node hosting the cell informs the source node 404 that the UE 402 successfully performed the handover in its cell so that the source node 404 may cancel the resources reserved by the remaining target candidate nodes 406. In addition, in the event that the time between handover preparations (and thus resource reservations) is unknown, source node 404 may enable release of reserved resources before UE 402 performs the handover.

If multiple cells are prepared to further enhance robustness and the UE 402 accesses one of them, then at 414, a set of resources may be reserved when the UE 402 is monitoring conditions and not performing a handover. Thus, the network may select target candidate cells 406 and keep the number of target candidate cells at a reasonable amount or below a pre-configured threshold amount, particularly in resource constrained scenarios, such as under high load. In various aspects, the network or base station may communicate the selected target cell 406 in a network indication via a first L1 communication, a first L2 communication, or L1 inter-cell dynamic scheduling Downlink Control Information (DCI).

One benefit of conditional handover utilization for L1/L2 centric inter-cell mobility is that UE 402 has stored handover commands for multiple candidate cell configurations, which reduces outage time even if a failure occurs. At 416, a failure may be detected when the mobile terminal is monitoring conditions. In legacy operation, the UE 402 will perform cell selection (i.e., select a neighboring cell to connect to) and continue the re-establishment procedure. However, with the introduction of conditional handoffs, when the same failure type (e.g., radio link failure or handover failure) is detected, the UE 402 may prioritize cells with stored handover commands and not perform re-establishment, but rather perform conditional handoffs, thereby reducing outage time and signaling over the air interface.

While the methods described in this disclosure are illustrated and described herein as a series of acts or events, it will be appreciated that the illustrated ordering of such acts or events are not to be interpreted in a limiting sense. For example, some acts may occur in different orders and/or concurrently with other acts or events apart from those illustrated and/or described herein. Moreover, not all illustrated acts may be required to implement one or more aspects or embodiments of the present description. Further, one or more of the acts depicted herein may occur in one or more separate acts and/or phases. For ease of description, reference may be made to the above figures. However, the methods are not limited to any particular embodiments or examples provided within the present disclosure, and may be applied to any of the systems disclosed herein.

Referring to fig. 5, an exemplary process flow for L1/L2 centric inter-cell mobility for conditional handoff operations with L1/L2 communications is shown. The process flow 500 begins at 502, where a network or source gNB 110 (e.g., 111a, 300, 404, etc.) pre-configures a plurality of candidate cells to a UE 101 (101 a, 300, 402, etc.). The UE 101 may store candidate cell configurations to be used at a later time or in the event of failure. Such configurations may include measurement conditions, restrictions, indications, resources, thresholds for L1/L2 centric inter-cell mobility.

At 504, the UE 101 can perform target cell selection and beam selection in the target cell. The UE 101 may perform a cell change according to a Network (NW) indication or a condition indicated by the NW. The NW selects a beam in the selected candidate cell either by NW indication or based on a condition indicated by the NW.

The UE 101 then switches to the selected candidate cell at 506. The UE 101 treats the candidate cell as a serving cell and applies the configuration of the candidate cell in response to a condition being met or according to the received indication. The UE 101 performs UL synchronization (if needed) in a target cell that has not been synchronized by the UL Random Access Channel (RACH). In addition, the UE 101 sends a cell change complete indication to the selected candidate cell. Alternatively or additionally, the UE 101 may switch to the previous serving cell as one of the candidate cells and maintain a store of the configuration of all candidate cells for later use.

A determination is made as to whether successful completion has occurred. If a failure is determined, as detected by a timer or a UL synchronization failure, the UE 101 may 1) switch back to the previous serving cell at 508. Alternatively, if the quality of the cell is good or the condition is met, the UE 101 may reselect to another candidate cell.

The framework for conditional handover is mainly specified in the Radio Resource Control (RRC) specification (TS 38.331) and Xn interface specification (TS 38.423). For example, also in Rel-16, conditional PSCell changes in the case of dual connectivity are supported, borrowing most of the functions defined for conditional handoffs. For example, in aspects herein, the preconfigured configuration content of the candidate cell configuration may be similar to the conditional handover configuration, except for the L1 or L2 configuration, where this may be altered for L1/L2 centric inter-cell mobility.

In aspects, the NW or gNB 110 may configure the UE 101 with a plurality of candidate cells for L1/L2 centric inter-cell mobility. Each service candidate serving cell configuration may be provided using conditional handover or CHO formats or containers. For example, DL or UL NAS signaling messages may be used. Alternatively or additionally, the L1 DCI or L2 MAC CE may provide candidate cell configurations for different candidate cells. Here, a Radio Resource Management (RRM) measurement event need not be provided to trigger a handover operation. The candidate cell configuration may include a mapping between a Transmission Configuration Indicator (TCI) state and candidate cells to UEs 101.

In one aspect, the configuration of each candidate cell may include an L1/L2/L3 configuration for the candidate cell or one or more restrictions on L1/L2-based cell change mobility. For example, candidate cell configurations may only allow cell change mobility or handover by providing only L1 configurations or being allowed to provide L1 and L2 configurations.

In an aspect, each candidate cell configuration may include a Carrier Aggregation (CA)/DC configuration, and an indication that the candidate cell is a PCell or PSCell. If the gNB 110 does not provide configuration for one or more candidate cells, the UE 101 can use the configuration for the current serving cell (e.g., 404) when switching to the candidate cell. Alternatively or additionally, the gNB 110 may provide a set of L1/L2/L3 configurations for a group of cells, where the cells may be connected based on an ideal backhaul, for example.

Upon receiving the configuration of the candidate cell, the UE 101 may store the configuration of the candidate cell. Then, the UE 101 may execute the configuration application when receiving the candidate cell configuration or when the candidate cell configuration is applied later. In the event of a candidate cell reception failure, the UE 101 may perform an RRC configuration failure procedure, such as triggering RRC connection reestablishment (for the primary cell group (MCG) case) or Secondary Cell Group (SCG) failure recovery (for the SCG case). In the event that the configuration reception is successful, the UE 101 may then deliver an rrcrecon configuration complete message to the current serving cell (e.g., UE 405), as described at 422 of fig. 4.

In one aspect related to target cell selection, the UE 101 receiving a condition indicating a cell change for L1/L2 centric inter-cell mobility may include L1 signaling indicating a handover to a candidate cell #X. The network or gNB 404 may indicate candidate cells to the UE 101 via L1 Downlink Control Information (DCI). Alternatively or additionally, NW or gNB 404 may indicate the TCI state of candidate cell #x via L1 DCI. Alternatively or additionally, NW or gNB 404 may indicate multiple TCI states of candidate cell #x via L1 DCI.

In another aspect related to target cell selection, the UE 101 receiving a condition to indicate a cell change for L1/L2 centric inter-cell mobility may include L2 signaling indicating a handover to a candidate cell #Y. Similar to the L1 DCI, L2 signaling may also be used to indicate one or more TCI states of candidate cell #y. L2 signaling may include L2 MAC CEs to achieve the same purpose.

In another aspect related to target cell selection, a cell handover or change to another candidate cell (e.g., candidate #Z) may be based on measurement conditions of the candidate cell. The measurement condition of the candidate cell may be an L3 RRM measurement or an L1 measurement. Based on the L3 RRM measurements, the UE 101 may reuse the current CHO conditions, which may be based on measurement events A3/A5, for example. Based on the L1RRM measurements, the network may indicate a threshold and an average window (optional) for the candidate cells.

The UE 101 may perform L1 measurements of the candidate cells in accordance with various aspects. If the L1 measurement of the candidate cell is greater than or equal to (> =) the threshold, then the condition for L1/L2 centric inter-cell mobility may be met and a cell change triggered by the UE 101. Alternatively or additionally, the condition may be met if the average of the L1 measurements of the candidate cells is greater than a (>) threshold during a window (configured) or configured period of time. Alternatively or additionally, the condition may be met if the L1 measurement of the candidate cell is greater than the result of the serving cell plus a differential delta (configured). The conditions that trigger L1/L2 based cell change may be configured by, for example, one or more of L3/L2/L1 signaling.

For beam selection aspects in the target cell (e.g., the gNB 406), the network conditions or network indications may be communicated to the UE 101 via any of L1/L2/L3 signaling or messaging. In one aspect, the network may explicitly indicate the beam of the target candidate cell for initial access/data transmission. Beam information for initial access may be delivered along with a cell change indication.

Additionally or alternatively, beam selection may be performed by the UE 101 within the NW-configured beam set as provided by the base station, such as the source cell 404. Thus, in this regard, the NW may signal to the UE 101 via L1/L2/L3 signaling an indication of more than one beam of the candidate cell. The UE 101 may select a beam from the set according to the beam quality of the target candidate cell (e.g., the gNB 406). For this embodiment, the UE 101 may select the beam with the best radio quality for initial access based on the evaluation according to one or more criteria herein. Alternatively or additionally, the UE 101 may select any beam suitable for (above a threshold (configured or predefined)) initial access.

Additionally or alternatively, beam selection by the UE 101 may be performed outside of the NW-configured beam set or beam options of the candidate cell provided by the network or base station. If the NW does not indicate a beam for the candidate cell, or the indicated beam does not have good quality meeting a threshold, the UE 101 may select a beam outside of the configuration set or not indicated, which may be based on, for example, a probability of beam quality or other relevant beam criteria. Alternatively or additionally, the UE 101 may select a beam based on UE measurements on the selected candidate cell and select a preamble/PRACH resource according to the quality of the Downlink (DL) beam.

Referring to fig. 6, an exemplary process flow for L1/L2 centric inter-cell mobility for conditional handoff operations with L1/L2 communications is shown. Process flow 600 illustrates UE behavior to perform or trigger cell change. Process flow 600 begins at 602, where the UE selects a candidate cell from a plurality of serving cells, and further applies a candidate cell configuration and switches the candidate cell to a serving cell (e.g., gNB 406). In one aspect, at 604, the UE 101 can store the previous serving cell (e.g., 404) with the received candidate cell configuration for selection. In this way, the UE 101 may fall back to the previous serving cell at a later time using the configuration of the previous serving cell, or select another candidate cell configuration at that time. At 606, the UE performs data transmission/reception and measurement according to the L3/L2/L1 configuration of the selected candidate cell. At 608, the UE 101 can acquire DL timing of the serving cell. At 608, the UE performs data transmission/reception and measurement according to the L3/L2/L1 configuration of the selected candidate cell. At 610, the UE 101 can provide a cell change Acknowledgement (ACK) to the network or a base station to a serving cell (e.g., 406).

In an aspect, the UE may send the cell change ACK via L1 message, L2 message, or L3 message signaling. L1 signaling includes a Scheduling Request (SR) transmission or a specific Physical Uplink Control Channel (PUCCH) transmission. L2 signaling may be MAC CEs (e.g., any UL MAC CE or a different or new dedicated MAC CE). The L3 signaling may be an rrcrecon configuration complete message, a different RRC message, or any Downlink Control Channel (DCCH) message.

In another aspect, the UE 101 may deliver the cell change ACK message in a different manner. One way to deliver a cell change ACK may be via a RACH procedure. As part of the RACH procedure to establish UL synchronization, the NW may indicate the target cell to access through a preamble/PRACH in a change indication sent to the UE 101 cell. Additionally or alternatively, the beam selection for initial access may be outside the NW-indicated set of cell candidate configurations. Additionally or alternatively, the UE 101 does not have UL synchronization in the target cell for providing an ACK via RACH procedure. In another way, the UE 101 may deliver the cell change ACK via SR transmission. Here, the UE 101 may use the SR to deliver the cell change ACK message according to the TCI state of NW indication for requesting UL grant for data transmission.

For example, the UE 101 may transmit a cell change acknowledgement via a RACH procedure in response to: the network indication includes a candidate cell to be accessed by a preamble/Physical Random Access Channel (PRACH) for a cell change indication, a beam selection for initial access to the candidate cell outside of one or more beams indicated by the network indication, or the candidate cell has no Uplink (UL) synchronization. The UE 101 may also transmit a cell change acknowledgement via SR transmission in response to delivering a Scheduling Request (SR) according to a Transmission Configuration Indication (TCI) state of the network indication.

In other aspects, the UE 101 may detect a cell change success or failure. For example, when successful, the UE 101 may transmit an acknowledgement of the cell change via a RACH procedure, and when successful, the cell change is successful so that data may be transmitted and received. The UE may then apply the configuration of the cell and start dedicated data transmission/reception and also monitor other candidate cells of the cell candidate configuration by performing measurements.

When using a non-RACH procedure (e.g., transmitting an ACK using a scheduling request), the UE 101 may determine that the cell change was successful in response to receiving the UE-specific DCI transmission within a predefined period of time after the SR transmission. Alternatively or additionally, the UE 101 may determine success by receiving a UE-specific DCI transmission for scheduling within a predetermined period of time without an SR transmission. Successful may also be considered when acknowledgements are transmitted/received within a predetermined period of time, or when acknowledgements are successfully transmitted within a predetermined period of time.

Alternatively, in addition, the UE may detect failure of the cell change in response to a RACH procedure failure, an SR transmission failure (where the number of SR transmissions exceeds a maximum pre-configured number). In one aspect, failure may be considered when UE 101 does not receive a UE-specific schedule or does not deliver a cell change ACK to NW within a period of time configured or indicated by the NE. This may be achieved, for example, by reusing the T304 timer.

In response to the detected cell change failure, the UE 101 is operable to perform a fallback to a previous serving cell (e.g., the gNB 404) based on an evaluation of candidate cell configurations among a plurality of candidate cell configurations stored in memory. Alternatively or additionally, the UE may access another candidate cell in the plurality of candidate cell configurations based on a quality threshold or one or more selection (S) criteria (e.g., may be a criterion for network conditions or an indicated criterion for selecting a cell change or a beam related to link evaluation or any of the criteria as described herein).

Referring to fig. 7, an exemplary L1/L2 centric inter-cell mobility for a UE 702 (e.g., UE 101, 300, 402, etc.) using L1/L2 communications for conditional handover operations between a plurality of different cells, including cell #1 704, cell #2 706, and cell #3 708, is illustrated. The different cell handover scenarios 709, 719, 729 are shown in different orders by way of example, but are not limited to any particular order or condition, and any one or more of the aspects/embodiments discussed herein may be utilized.

At 709, the UE 702 stores the candidate configuration provided via the serving cell via RRC reconfiguration message 710. The gNB 704 or the current serving cell may provide this message 710 via an L1, L2, or L3 message. The UE 702 may then utilize these cell candidate configurations at a later time at 712 and provide an RRC reconfiguration complete message after the configuration has been established with the serving cell. For example, the serving cell may also provide an indication to the UE 702 to change cells to cell #2 using the L1/L2 indication. The UE 702 may then perform a cell change to cell #2 at 719 and provide a cell change ACK 716 to cell #2 706.

At scenario 729, the UE 702 may monitor candidate cells based on the received cell candidate configuration. As described herein, the condition may be indicated as part of serving cell signaling via L1 message, L2 message, L1 dynamically scheduled DCI, or L3 message. The conditions may be based on any conditional handoff condition (e.g., A3/A5 event) as described above, or other quality assessment such as an assessment of an L1/L2/L3 link. The conditions may also include restrictions for monitoring L1 or L2, or both L1 and L2 communications, or configuring L1 configuration or both L1 and L1 configuration for the candidate cell. In response to the condition being met, the UE 702 provides a cell change ACK 720 to the serving cell, which in turn may provide L2 signaling with conditions for monitoring cell #1 at 722. When the condition is met, the UE may further facilitate another L1/L2 centric inter-cell mobility, as with other cells in scenario 738. The L2 signaling may include, for example, L2 MAC CEs that may indicate candidate cells to monitor and one or more TCI states of the candidate cells. The UE 702 may then provide a cell change ACK to the initial serving cell #1 704 for effectuating the cell change and determining its success or failure. As described above, other scenarios may also be combined with one or more other aspects discussed herein.

Referring to fig. 8, an exemplary process flow 800 for a network device or component (e.g., UE 101, base station 110, AP 106, or other network component) is illustrated to perform L1/L2 centric inter-cell mobility in accordance with various aspects or embodiments herein.

Process flow 800 may begin at 802, where a plurality of candidate cell configurations corresponding to different candidate cells for L1/L2 centric inter-cell mobility, and a network indication or network condition are received via a first layer 1 (L1) communication, a first layer 2 (L2) communication, or an inter-L1 cell dynamic scheduling DCI. At 804, process flow 800 may include triggering a cell change to L1/L2 centric inter-cell mobility of the candidate cell in response to the network condition satisfying the threshold.

One or more candidate cell configurations of the set of candidate cell configurations may include at least one of: l1 configuration, L2 configuration, or layer 3 (L3) configuration, and restrictions on L1/L2 centric inter-cell mobility to the UE, such as allowing only L1, L2, or both configurations/communications for cell change. The network conditions may include an indication of at least one of: l1 communication triggering cell change, L2 communication triggering cell change, or measurement of candidate cells based on L1 measurement results, or conditions for monitoring conditional handover of one or more specific candidate cells of the candidate cell configuration.

The UE may receive a network indication or another network indication of one or more beams of the candidate cell selected for initial access or data transmission via L1 signaling, L2 signaling, or L3 signaling. The UE may then select a beam of the one or more beams of the candidate cell or a beam other than the one or more beams based on the quality measurements. If no beam meets a threshold or a differential increment between the threshold plus the quality of the link (e.g., L1, L2, etc.), the UE may fall back to the serving cell on which it was previously operating or search for a beam outside the received set of beams based on probabilities or metrics measured by the UE on the selected candidate cell and select a preamble/PRACH resource, e.g., according to the DL quality of the beam.

As used in this specification, the term "processor" may refer to essentially any computing processing unit or device, including but not limited to including single-core processors; a single processor having software multithreading capability; a multi-core processor; a multi-core processor having software multithreading capability; a multi-core processor having hardware multithreading; a parallel platform; and a parallel platform with distributed shared memory. Additionally, a processor may refer to an integrated circuit, an application specific integrated circuit, a digital signal processor, a field programmable gate array, a programmable logic controller, a complex programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions and/or processes described herein. Processors may utilize nanoscale architectures such as, but not limited to, molecular and quantum dot based transistors, switches, and gates in order to optimize space usage or enhance performance of mobile devices. A processor may also be implemented as a combination of computing processing units.

Embodiments (implementations) may include a subject matter, such as a method, an apparatus for performing the acts of the method or blocks of the method, at least one machine readable medium including instructions that, when executed by a machine (e.g., a processor with memory, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), etc.), cause the machine to perform the acts of a method or apparatus or system of concurrent communication using multiple communication techniques in accordance with implementations and embodiments described herein.

A first embodiment is a User Equipment (UE) comprising: a memory; and a processor configured to: receiving a plurality of candidate cell configurations corresponding to different candidate cells for inter-cell mobility in a layer 1 (L1)/layer 2 (L2) center in a handover operation; receiving a network indication to switch to one of the different candidate cells via a first L1 communication, a first L2 communication, an inter-L1 cell dynamic scheduling Downlink Control Information (DCI), or a layer 3 (L3) message; and performing a cell change of the L1/L2 centric inter-cell mobility in the handover operation to the one of the different candidate cells in response to a threshold associated with the network indication or with a network condition being met.

The second embodiment may include the first embodiment, wherein the processor is further configured to: selecting a candidate cell from the plurality of candidate cell configurations based on the network indication or the network condition; and triggering the cell change to the candidate cell via a second L1 communication, a second L2 communication, or a layer 3 (L3) communication.

The third embodiment may include the first embodiment or the second embodiment, wherein the processor is further configured to: a selected beam for beam change in a candidate cell is received, wherein the selected beam is determined based on an evaluation of a condition of the first L1 communication or the first L2 communication, based on a network indication received from a second L1 communication or a second L2 communication, or based on the network indication received from the first L1 communication or the first L2 communication.

A fourth embodiment may include any one or more of the first to third embodiments, wherein the processor is further configured to: providing a cell change complete message to a candidate cell, wherein the cell change complete message comprises an L1 message or an L2 message that is invisible to a Radio Resource Control (RRC) layer, or an L3 message comprising a Downlink Control Channel (DCCH) message, wherein the L1 message comprises a Scheduling Request (SR) transmission or a Physical Uplink Control Channel (PUCCH) transmission, wherein the L2 message comprises a Medium Access Control (MAC) Control Element (CE).

A fifth embodiment may include any one or more of the first to fourth embodiments, wherein the processor is further configured to: the candidate cell is configured as a serving cell and a candidate cell configuration associated with the candidate cell is applied in response to a successful Random Access Channel (RACH) procedure or a cell change confirm transmission being successful for a period of time.

A sixth embodiment may include any one or more of the first to fifth embodiments, wherein the processor is further configured to: performing a handover to a previous serving cell as a candidate cell in response to a failure of the cell change; and storing the plurality of candidate cell configurations in the memory to initiate another handover operation based on the plurality of candidate cell configurations and the network indication or the network condition.

A seventh embodiment may include any one or more of the first to sixth embodiments, wherein the processor is further configured to: detecting a failure of the cell change of the L1/L2 centric inter-cell mobility in the handover operation based on a timer or an Uplink (UL) synchronization failure to a candidate cell; and in response to the failure, switching to a previous serving cell or reselecting another candidate cell of the plurality of candidate cell configurations in accordance with one or more quality measurements.

An eighth embodiment may include any one or more of the first to seventh embodiments, wherein the processor is further configured to: the method includes receiving the plurality of candidate cell configurations based on a Conditional Handover (CHO) format and a mapping between Transmission Configuration Indication (TCI) status and candidate cells, wherein the candidate cell configurations include at least one of: l1 configuration, L2 configuration, L3 configuration, restriction of the cell change for the L1/L2 centric inter-cell mobility, carrier Aggregation (CA)/Dual Connectivity (DC) configuration, or designation including primary cell (PCell) or primary secondary cell (PSCell).

A ninth embodiment may include any one or more of the first to eighth embodiments, wherein the processor is further configured to: in response to not receiving a candidate cell configuration, performing the cell change to the L1/L2 centric inter-cell mobility of the candidate cell based on a current serving cell configuration; or a set of L1, L2, or L3 candidate cell configurations for a plurality of cells connected based on an ideal backhaul connection.

A tenth embodiment may include any one or more of the first to ninth embodiments, wherein the processor is further configured to: performing a Radio Resource Control (RRC) configuration failure procedure by triggering RRC connection reestablishment or Secondary Cell Group (SCG) failure recovery in response to the candidate cell reception failure; and transmitting an RRC reconfiguration complete message to the candidate cell configured by the current serving cell in response to a successful configuration reception.

An eleventh embodiment may include any one or more of the first to tenth embodiments, wherein the processor is further configured to: receiving a network indication regarding an L1 inter-cell dynamic scheduling DCI or an L2 Medium Access Control (MAC) Control Element (CE), wherein the network indication indicates one or more TCI states of a candidate cell; or performing the cell change to the L1/L2 centric inter-cell mobility of the candidate cell based on a measurement condition including an L3 Radio Resource Management (RRM) measurement result or an L1 measurement result.

The twelfth embodiment may include any one or more of the first to eleventh embodiments, wherein the L3 RRM measurement result includes an A3 or A5 measurement event.

A thirteenth embodiment may include any one or more of the first to twelfth embodiments, wherein the L1 measurement is based on at least one of: a first comparison of the threshold provided by the network indication or the network condition with the L1 measurement of a candidate cell, a second comparison of an average of the L1 measurement of the candidate cell within a window with the threshold, or a third comparison of the L1 measurement of the candidate cell with a serving cell measurement and an incremental difference configured by the network indication or the network condition.

A fourteenth embodiment may include any one or more of the first to thirteenth embodiments, wherein the processor is further configured to: receiving one or more beams for the candidate cell via the L1 communication, the L2 communication, or the L3 communication; responsive to indicating a plurality of beams in the network indication or another communication, selecting a beam based on a quality threshold; or in response to not receiving the network indication comprising the one or more beams or the one or more beams comprising a quality below the quality threshold, selecting a beam other than the one or more beams for the selected candidate cell based on UE measurements on the candidate cell, and selecting a preamble or Physical Random Access Channel (PRACH) resource based on the quality of the selected beam.

A fifteenth embodiment may be a baseband processor comprising: a memory; a processor configured to: receiving a plurality of candidate cell configurations corresponding to different candidate cells for L1/L2 centric inter-cell mobility via a first layer 1 (L1) communication, a first layer 2 (L2) communication, an L1 inter-cell dynamic scheduling Downlink Control Information (DCI), or a layer 3 (L3) message, and a network indication or network condition; and triggering the cell change for L1/L2 centric inter-cell mobility in response to meeting a threshold associated with the network indication or with the network condition.

A sixteenth embodiment may include the fifteenth embodiment, wherein the processor is further configured to: selecting a candidate cell from the plurality of candidate cell configurations based on the network indication or the network condition; and triggering the cell change to the candidate cell via a second L1 communication or a second L2 communication.

A seventeenth embodiment may include any one or more of the fifteenth to sixteenth embodiments, wherein the processor is further configured to: in response to: the network indication includes a candidate cell to be accessed by a preamble/Physical Random Access Channel (PRACH) for a cell change indication, a beam selection for initial access to the candidate cell being outside of one or more beams indicated by the network indication, or the candidate cell not having Uplink (UL) synchronization, transmitting a cell change acknowledgement via a Random Access Channel (RACH) procedure; and transmitting the cell change acknowledgement via the SR transmission in response to delivering a Scheduling Request (SR) according to a Transmission Configuration Indication (TCI) state of the network indication.

An eighteenth embodiment may include any one or more of the fifteenth to seventeenth embodiments, wherein the processor is further configured to: the success of the cell change is determined under the following conditions: in response to receiving an acknowledgement of a UE-specific DCI transmission to transmit the cell change via a non-RACH procedure within a predefined period of time after an SR transmission, the acknowledgement being transmitted within the predefined period of time or the acknowledgement being successfully transmitted within the predefined period of time, receiving the UE-specific DCI transmission for scheduling without an SR transmission within the predefined period of time.

A nineteenth embodiment may include any one or more of the fifteenth to eighteenth embodiments, wherein the processor is further configured to: a fallback to a previous serving cell is performed based on an evaluation of a candidate cell configuration of the plurality of candidate cell configurations stored in the memory, or another candidate cell of the plurality of candidate cell configurations is accessed based on a quality threshold or one or more selection (S) criteria.

A twentieth embodiment may be a tangible computer-readable storage device storing executable instructions that, in response to execution, cause one or more processors of a User Equipment (UE) to perform operations comprising: receiving a plurality of candidate cell configurations corresponding to different candidate cells for L1/L2 centric inter-cell mobility via a first layer 1 (L1) communication, a first layer 2 (L2) communication, an L1 inter-cell dynamic scheduling Downlink Control Information (DCI), or a layer 3 (L3) message, and a network indication or network condition; and triggering a cell change to the L1/L2 centric inter-cell mobility of the candidate cell in response to the network condition satisfying a threshold.

A twenty-first embodiment may include the twentieth embodiment, wherein a candidate cell configuration of the plurality of candidate cell configurations includes at least one of: l1 configuration, L2 configuration, or layer 3 (L3) configuration, which includes restrictions on the L1/L2 centric inter-cell mobility.

A twenty-second embodiment may include any one or more of the twentieth to twenty-first embodiments, wherein the network condition includes at least one of: l1 communication triggering the cell change, L2 communication triggering the cell change, or measurement of candidate cells based on L1 measurement results or conditions of conditional handover.

A twenty-third embodiment may include any one or more of the twentieth to twenty-second embodiments, the operations further comprising: receiving the network indication or another network indication of one or more beams of the candidate cell for initial access or data transmission via L1 signaling, L2 signaling, or L3 signaling; and selecting a beam of the one or more beams of the candidate cell or a beam other than the one or more beams based on the quality measurement.

A twenty-fourth embodiment may include any one or more of the twentieth to twenty-third embodiments, the operations further comprising: in response to the non-RACH procedure being deemed to have failed, a cell change success is determined by transmitting an acknowledgement of the cell change via the RACH procedure.

A twenty-fifth embodiment can be a base station comprising: a memory; and a processor configured to: generating a plurality of candidate cell configurations for configuring inter-cell mobility centered on layer 1 (L1)/layer 2 (L2) in a handover operation; and transmitting the plurality of candidate cell configurations and at least one of: network conditions or network indications to be used to trigger the handover operation via L1 communication, L2 communication, L1 inter-cell dynamic scheduling Downlink Control Information (DCI) or layer 3 (L3) messages.

A twenty-sixth embodiment may include the twenty-fifth embodiment, wherein the processor is further configured to: a candidate cell configuration of the plurality of candidate cell configurations is transmitted using a conditional handover signaling format or container, and a Transmission Configuration Indication (TCI) state of the candidate cell configuration is transmitted via the L1 inter-cell dynamic scheduling DCI or L2 medium access control element (MAC CE).

A twenty-seventh embodiment may include any one or more of the twenty-fifth to twenty-sixth embodiments, wherein the processor is further configured to: transmitting a mapping between a Transmission Configuration Indication (TCI) state and candidate cells, wherein a candidate cell configuration of the plurality of candidate cell configurations comprises at least one of: l1 configuration, L2 configuration, L3 configuration, restrictions on cell change for L1/L2-centric inter-cell mobility, carrier Aggregation (CA)/Dual Connectivity (DC) configuration, or designation including primary cell (PCell) or primary secondary cell (PSCell).

A twenty-eighth embodiment may include any one or more of the twenty-fifth to twenty-seventh embodiments, wherein the processor is further configured to: transmitting the network indication or another network indication of one or more beams of the candidate cell for initial access or data transmission via L1 signaling, L2 signaling or L3 signaling.

A twenty-ninth embodiment may include any one or more of the twenty-fifth to twenty-eighth embodiments, wherein the processor is further configured to: transmitting at least one of the following: an L1 measurement threshold, window period, or differential delta to enable L1 measurements of candidate cells to be made to enable autonomous cell change for L1/L2 centric inter-cell mobility based on network conditions.

A thirty-first embodiment may include an apparatus comprising means for performing one or more elements of the method of or relating to any one of the first to twenty-first embodiments or any other method or process described herein.

A thirty-first embodiment may include one or more non-transitory computer-readable media comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of the method of or related to any one of the first to twenty-first embodiments or any other method or process described herein.

A thirty-second embodiment may comprise an apparatus comprising logic means, modules, or circuitry for performing one or more elements of the method of or in connection with any one of the first to twenty-first embodiments or any other method or process described herein.

A thirty-third embodiment may include the method, technique, or process of any one of the first to twenty-first embodiments or portions or components thereof.

A thirty-fourth embodiment may comprise an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform the method, technique, or process, or portion thereof, of or relating to any one of the first to twenty-first embodiments.

A thirty-fifth embodiment may comprise a signal, or portion or component thereof, as described in or relating to any one of embodiments 1 to 29.

A thirty-sixth embodiment may include a datagram, packet, frame, segment, protocol Data Unit (PDU) or message, or portion or component thereof, as described in any one of the first through twenty-first embodiments or otherwise described in this disclosure.

A thirty-seventh embodiment may comprise the data-encoded signal, or a portion or component thereof, as described in any one of the first through twenty-first embodiments or otherwise described in this disclosure.

A thirty-eighth embodiment may include a signal encoded with a datagram, packet, frame, segment, protocol Data Unit (PDU) or message, or a portion or part thereof, as described in any one of the first to twenty-first embodiments or otherwise described in this disclosure.

A thirty-ninth embodiment may include an electromagnetic signal bearing computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors causes the one or more processors to perform the method, technique, or process, or portion thereof, as set forth in or related to any one of the first through twenty-first embodiments.

A fortieth embodiment may include a computer program comprising instructions, wherein execution of the program by a processing element will cause the processing element to perform the method, technique, or process, or portion thereof, of or in connection with any one of the first to twenty-first embodiments.

A forty-first embodiment may include a signal in a wireless network as shown and described herein.

A forty-second embodiment may include a method of communicating in a wireless network as shown and described herein.

The forty-third embodiment may include a system for providing wireless communications as shown and described herein.

The forty-fourth embodiment may include an apparatus for providing wireless communication as shown and described herein.

Furthermore, various aspects or features described herein may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include, but are not limited to, magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips), optical disks (e.g., compact Disk (CD), digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., EPROM, card, stick, key drive, etc.). Additionally, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data. Additionally, a computer program product may include a computer-readable medium having one or more instructions or code operable to cause a computer to perform the functions described herein.

Communication media embodies computer readable instructions, data structures, program modules or other structured or unstructured data in a data signal such as a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery or transmission media. The term "modulated data signal" or a signal means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in one or more signals. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media.

An exemplary storage medium may be coupled to the processor such 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. Further, in some aspects, the processor and the storage medium may reside in an ASIC. In addition, the ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. Furthermore, in some aspects, the processes and/or actions of a method or algorithm may reside as one or any combination or set of codes and/or instructions on a machine readable medium and/or computer readable medium, and may be incorporated into a computer program product.

In this regard, while the disclosed subject matter has been described in connection with various embodiments and corresponding figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiments for performing the same, similar, alternative or alternative functions of the disclosed subject matter without deviating therefrom. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but rather should be construed in breadth and scope in accordance with the appended claims.

In particular regard to the various functions performed by the above described components (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a "means") used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the disclosure. In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.

Claims (29)

1. A User Equipment (UE), comprising:

a memory; and

a processor configured to:

receiving a plurality of candidate cell configurations corresponding to different candidate cells for inter-cell mobility in a layer 1 (L1)/layer 2 (L2) center in a handover operation;

receiving a network indication to switch to one of the different candidate cells via a first L1 communication, a first L2 communication, an inter-L1 cell dynamic scheduling Downlink Control Information (DCI), or a layer 3 (L3) message; and

in response to meeting a threshold associated with the network indication or with a network condition,

performing a cell change of the L1/L2 centric inter-cell mobility in the handover operation to the one of the different candidate cells.

2. The UE of claim 1, wherein the processor is further configured to:

selecting a candidate cell from the plurality of candidate cell configurations based on the network indication or the network condition; and

triggering the cell change to the candidate cell via a second L1 communication, a second L2 communication, or a layer 3 (L3) communication.

3. The UE of claim 1, wherein the processor is further configured to:

a selected beam for beam change in a candidate cell is received, wherein the selected beam is determined based on an evaluation of a condition of the first L1 communication or the first L2 communication, based on a network indication received from a second L1 communication or a second L2 communication, or based on the network indication received from the first L1 communication or the first L2 communication.

4. The UE of claim 1, wherein the processor is further configured to:

providing a cell change complete message to a candidate cell, wherein the cell change complete message comprises an L1 message or an L2 message that is invisible to a Radio Resource Control (RRC) layer, or an L3 message comprising a Downlink Control Channel (DCCH) message, wherein the L1 message comprises a Scheduling Request (SR) transmission or a Physical Uplink Control Channel (PUCCH) transmission, wherein the L2 message comprises a Medium Access Control (MAC) Control Element (CE).

5. The UE of claim 1, wherein the processor is further configured to:

the candidate cell is configured as a serving cell and a candidate cell configuration associated with the candidate cell is applied in response to a successful Random Access Channel (RACH) procedure or a cell change confirm transmission being successful for a period of time.

6. The UE of claim 1, wherein the processor is further configured to:

performing a handover to a previous serving cell as a candidate cell in response to a failure of the cell change; and

the plurality of candidate cell configurations is stored in the memory to initiate another handover operation based on the plurality of candidate cell configurations and the network indication or the network condition.

7. The UE of claim 1, wherein the processor is further configured to:

detecting a failure of the cell change of the L1/L2 centric inter-cell mobility in the handover operation based on a timer or an Uplink (UL) synchronization failure to a candidate cell; and

in response to the failure, switching to a previous serving cell or reselecting another candidate cell of the plurality of candidate cell configurations in accordance with one or more quality measurements.

8. The UE of claim 1, wherein the processor is further configured to:

the method includes receiving the plurality of candidate cell configurations based on a Conditional Handover (CHO) format and a mapping between Transmission Configuration Indication (TCI) status and candidate cells, wherein the candidate cell configurations include at least one of: l1 configuration, L2 configuration, L3 configuration, restriction of the cell change for the L1/L2 centric inter-cell mobility, carrier Aggregation (CA)/Dual Connectivity (DC) configuration, or designation including primary cell (PCell) or primary secondary cell (PSCell).

9. The UE of claim 1, wherein the processor is further configured to:

in response to not receiving a candidate cell configuration, performing the cell change to the L1/L2 centric inter-cell mobility of the candidate cell based on a current serving cell configuration; or alternatively

A set of L1, L2, or L3 candidate cell configurations for a plurality of cells connected based on an ideal backhaul connection is received.

10. The UE of claim 9, wherein the processor is further configured to:

performing a Radio Resource Control (RRC) configuration failure procedure by triggering RRC connection reestablishment or Secondary Cell Group (SCG) failure recovery in response to the candidate cell reception failure; and

and transmitting an RRC reconfiguration complete message to the candidate cell configured by the current serving cell in response to successful configuration reception.

11. The UE of claim 1, wherein the processor is further configured to:

receiving a network indication regarding an L1 inter-cell dynamic scheduling DCI or an L2 Medium Access Control (MAC) Control Element (CE), wherein the network indication indicates one or more TCI states of a candidate cell; or alternatively

The cell change to the L1/L2 centric inter-cell mobility of the candidate cell is performed based on a measurement condition including an L3 Radio Resource Management (RRM) measurement result or an L1 measurement result.

12. The UE of claim 11, wherein the L3 RRM measurement result comprises an A3 or A5 measurement event.

13. The UE of claim 11, wherein the L1 measurement is based on at least one of: a first comparison of the threshold provided by the network indication or the network condition with the L1 measurement of a candidate cell, a second comparison of an average of the L1 measurement of the candidate cell within a window with the threshold, or a third comparison of the L1 measurement of the candidate cell with a serving cell measurement and an incremental difference configured by the network indication or the network condition.

14. The UE of claim 1, wherein the processor is further configured to:

receiving one or more beams for a candidate cell via the L1 communication, the L2 communication, or the L3 communication;

responsive to indicating a plurality of beams in the network indication or another communication, selecting a beam based on a quality threshold; or alternatively

Responsive to not receiving the network indication comprising the one or more beams or the one or more beams comprising a quality below the quality threshold, a beam other than the one or more beams for the selected candidate cell is selected based on UE measurements on the candidate cell, and a preamble or Physical Random Access Channel (PRACH) resource is selected based on the quality of the selected beam.

15. A baseband processor, comprising:

a memory;

a processor configured to:

receiving a plurality of candidate cell configurations corresponding to different candidate cells for L1/L2 centric inter-cell mobility via a first layer 1 (L1) communication, a first layer 2 (L2) communication, an L1 inter-cell dynamic scheduling Downlink Control Information (DCI), or a layer 3 (L3) message, and a network indication or network condition; and

Triggering the cell change for L1/L2 centric inter-cell mobility in response to meeting a threshold associated with the network indication or with the network condition.

16. The baseband processor of claim 15, wherein the processor is further configured to:

selecting a candidate cell from the plurality of candidate cell configurations based on the network indication or the network condition; and

the cell change to the candidate cell is triggered via a second L1 communication or a second L2 communication.

17. The baseband processor of claim 15, wherein the processor is further configured to:

in response to: the network indication includes a candidate cell to be accessed by a preamble/Physical Random Access Channel (PRACH) for a cell change indication, a beam selection for initial access to the candidate cell outside of one or more beams indicated by the network indication or the candidate cell has no Uplink (UL) synchronization,

transmitting a cell change acknowledgement via a Random Access Channel (RACH) procedure; and

in response to delivering a Scheduling Request (SR) according to a Transmission Configuration Indication (TCI) state of the network indication,

the cell change acknowledgement is transmitted via the SR transmission.

18. The baseband processor of claim 15, wherein the processor is further configured to:

the success of the cell change is determined under the following conditions: in response to receiving a UE-specific DCI transmission within a predefined period of time after an SR transmission without an SR transmission, transmitting an acknowledgement of the cell change via a non-RACH procedure, the acknowledgement being transmitted within the predefined period of time or the acknowledgement being successfully transmitted within the predefined period of time.

19. The baseband processor of claim 15, wherein the processor is further configured to:

a fallback to a previous serving cell is performed based on an evaluation of a candidate cell configuration of the plurality of candidate cell configurations stored in the memory, or another candidate cell of the plurality of candidate cell configurations is accessed based on a quality threshold or one or more selection (S) criteria.

20. A tangible computer-readable storage device storing executable instructions that, in response to execution, cause one or more processors of a User Equipment (UE) to perform operations comprising:

Receiving a plurality of candidate cell configurations corresponding to different candidate cells for L1/L2 centric inter-cell mobility via a first layer 1 (L1) communication, a first layer 2 (L2) communication, an L1 inter-cell dynamic scheduling Downlink Control Information (DCI), or a layer 3 (L3) message, and a network indication or network condition; and

and triggering the cell change of the inter-cell mobility centered on L1/L2 to a candidate cell in response to the network condition meeting a threshold.

21. The tangible computer readable storage device of claim 20, wherein a candidate cell configuration of the plurality of candidate cell configurations comprises at least one of: l1 configuration, L2 configuration, or layer 3 (L3) configuration, which includes restrictions on the L1/L2 centric inter-cell mobility.

22. The tangible computer readable storage device of claim 20, wherein the network conditions comprise at least one of: l1 communication triggering the cell change, L2 communication triggering the cell change, or measurement of candidate cells based on L1 measurement results or conditions of conditional handover.

23. The tangible computer-readable storage device of claim 20, the operations further comprising:

Receiving the network indication or another network indication of one or more beams of the candidate cell for initial access or data transmission via L1 signaling, L2 signaling, or L3 signaling; and

a beam of the one or more beams of the candidate cell or a beam other than the one or more beams is selected based on the quality measurements.

24. The tangible computer-readable storage device of claim 20, the operations further comprising:

in response to the non-RACH procedure being deemed to have failed, a cell change success is determined by transmitting an acknowledgement of the cell change via the RACH procedure.

25. A base station, comprising:

a memory; and

a processor configured to:

generating a plurality of candidate cell configurations for configuring inter-cell mobility centered on layer 1 (L1)/layer 2 (L2) in a handover operation; and

transmitting the plurality of candidate cell configurations and at least one of: network conditions or network indications to be used to trigger the handover operation via L1 communication, L2 communication, L1 inter-cell dynamic scheduling Downlink Control Information (DCI) or layer 3 (L3) messages.

26. The base station of claim 25, wherein the processor is further configured to:

A candidate cell configuration of the plurality of candidate cell configurations is transmitted using a conditional handover signaling format or container, and a Transmission Configuration Indication (TCI) state of the candidate cell configuration is transmitted via the L1 inter-cell dynamic scheduling DCI or L2 medium access control element (MAC CE).

27. The base station of claim 25, wherein the processor is further configured to:

transmitting a mapping between a Transmission Configuration Indication (TCI) state and candidate cells, wherein a candidate cell configuration of the plurality of candidate cell configurations comprises at least one of: l1 configuration, L2 configuration, L3 configuration, restrictions on cell change for L1/L2-centric inter-cell mobility, carrier Aggregation (CA)/Dual Connectivity (DC) configuration, or designation including primary cell (PCell) or primary secondary cell (PSCell).

28. The base station of claim 25, wherein the processor is further configured to:

transmitting the network indication or another network indication of one or more beams of the candidate cell for initial access or data transmission via L1 signaling, L2 signaling, or L3 signaling.

29. The base station of claim 25, wherein the processor is further configured to:

Transmitting at least one of the following: an L1 measurement threshold, window period, or differential delta to enable L1 measurements of candidate cells to be made to enable autonomous cell change for L1/L2 centric inter-cell mobility based on network conditions.