CN117242835A

CN117242835A - WTRU power saving in active time

Info

Publication number: CN117242835A
Application number: CN202280032195.0A
Authority: CN
Inventors: 艾尔丹姆·巴拉; 李文一; 珍妮特·A·斯特恩-波科维茨; 保罗·马里内尔
Original assignee: InterDigital Patent Holdings Inc
Current assignee: InterDigital Patent Holdings Inc
Priority date: 2021-04-02
Filing date: 2022-03-31
Publication date: 2023-12-15
Also published as: CN118019092A

Abstract

The WTRU may be configured to receive a first downlink transmission in a first Search Space (SS) group (SSG). The first downlink transmission may include first configuration information associated with power saving and downlink transmission monitoring. The WTRU may be configured to monitor for a second downlink transmission based on the first configuration information. In the case where the first configuration information indicates a first value, the WTRU may be configured to monitor in the first SSG. In the case where the first configuration information indicates the second value, the WTRU may be configured to monitor in the second SSG. In the case where the first configuration information indicates the third value, the WTRU may be configured to skip downlink transmission monitoring in the first SSG and monitor in the first SSG for a first interval. The WTRU may receive a second downlink transmission based on the first configuration information.

Description

WTRU power saving in active time

Cross Reference to Related Applications

The present application claims the benefit of U.S. provisional patent application No. 63/170,177, filed on 2 months of 2021, U.S. provisional patent application No. 63/185,573, filed on 3 months of 2021, U.S. provisional patent application No. 63/228,888, filed on 21 months of 2021, 12, and 63,292,076, the disclosures of which are incorporated herein by reference in their entirety.

Background

Mobile communications using wireless communications continue to evolve. The fifth generation may be referred to as 5G. The former generation (legacy) mobile communication may be, for example, fourth generation (4G) Long Term Evolution (LTE).

Disclosure of Invention

Systems, methods, and tools for wireless transmit/receive unit (WTRU) power saving during active time are disclosed herein. The WTRU may include a processor configured to perform one or more actions. The processor may be configured to receive a first downlink transmission in a first Search Space (SS) group (SSG). The first downlink transmission may include first configuration information associated with power saving. The first configuration information may be associated with downlink transmission monitoring. The processor may be configured to monitor the second downlink transmission based on the first configuration information. In the case that the first configuration information indicates a first value, the processor may be configured to monitor the second downlink transmission in the first SSG. In the case where the first configuration information indicates the second value, the processor may be configured to monitor the second downlink transmission in the second SSG. In the case where the first configuration information indicates a third value, the processor may be further configured to: the downlink transmission monitoring is skipped in the first SSG for a first interval, and the second downlink transmission is monitored in the first SSG in response to the first interval ending. The processor may be configured to receive a second downlink transmission based on the first configuration information.

Drawings

Fig. 1A is a system diagram illustrating an exemplary communication system in which one or more disclosed embodiments may be implemented.

Fig. 1B is a system diagram illustrating an exemplary wireless transmit/receive unit (WTRU) that may be used within the communication system shown in fig. 1A, in accordance with an embodiment.

Fig. 1C is a system diagram illustrating an exemplary Radio Access Network (RAN) and an exemplary Core Network (CN) that may be used within the communication system shown in fig. 1A, according to an embodiment.

Fig. 1D is a system diagram illustrating another exemplary RAN and another exemplary CN that may be used in the communication system shown in fig. 1A, according to an embodiment.

Fig. 2 is a diagram showing an example of on-duration and off-duration in a DRX cycle.

Fig. 3 is a diagram illustrating an example of WUS and GOS in a DRX operation.

Fig. 4 is a diagram illustrating an example of a state transition of a WTRU based on PS bit indication and/or timer expiration.

Fig. 5 is a diagram illustrating an example of using a null state for PDCCH skipping.

Fig. 6 is a diagram showing an example of more than two states including an empty state.

Fig. 7 is a diagram showing an example of state transition based on implicit indication.

Fig. 8 is a diagram illustrating an example of a timeline of Downlink (DL) transmissions of corresponding HARQ processes.

Fig. 9 is a diagram illustrating an example of a timeline of Uplink (UL) transmission of a corresponding HARQ process.

Fig. 10A-10C illustrate exemplary handover and PDCCH monitoring skips.

Detailed Description

Fig. 1A is a schematic diagram illustrating an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. Communication system 100 may be a multiple-access system that provides content, such as voice, data, video, messages, broadcasts, etc., to a plurality of wireless users. Communication system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, communication system 100 may employ one or more channel access methods, such as Code Division Multiple Access (CDMA), time Division Multiple Access (TDMA), frequency Division Multiple Access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word DFT-spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter Bank Multicarrier (FBMC), and the like.

As shown in fig. 1A, the communication system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, RANs 104/113, CNs 106/115, public Switched Telephone Networks (PSTN) 108, the internet 110, and other networks 112, although it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment. As an example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a "station" and/or a "STA") may be configured to transmit and/or receive wireless signals and may include User Equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular telephones, personal Digital Assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hot spot or Mi-Fi devices, internet of things (IoT) devices, watches or other wearable devices, head Mounted Displays (HMDs), vehicles, drones, medical devices and applications (e.g., tele-surgery), industrial devices and applications (e.g., robots and/or other wireless devices operating in an industrial and/or automated processing chain environment), consumer electronic devices, devices operating on a commercial and/or industrial wireless network, and the like. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

Communication system 100 may also include base station 114a and/or base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106/115, the internet 110, and/or the other networks 112. As an example, the base stations 114a, 114B may be Base Transceiver Stations (BTSs), node bs, eNode bs (enbs), home Node bs, home eNode bs, gNode bs (gnbs), NR nodebs, site controllers, access Points (APs), wireless routers, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.

Base station 114a may be part of RAN 104/113 that may also include other base stations and/or network elements (not shown), such as Base Station Controllers (BSCs), radio Network Controllers (RNCs), relay nodes, and the like. Base station 114a and/or base station 114b may be configured to transmit and/or receive wireless signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage of wireless services to a particular geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, a cell associated with base station 114a may be divided into three sectors. Thus, in an embodiment, the base station 114a may include three transceivers, i.e., one for each sector of a cell. In an embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of a cell. For example, beamforming may be used to transmit and/or receive signals in a desired spatial direction.

The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio Frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable Radio Access Technology (RAT).

More specifically, as noted above, communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, or the like. For example, a base station 114a in the RAN 104/113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) terrestrial radio access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interfaces 115/116/117.WCDMA may include communication protocols such as High Speed Packet Access (HSPA) and/or evolved HSPA (hspa+). HSPA may include high speed Downlink (DL) packet access (HSDPA) and/or High Speed UL Packet Access (HSUPA).

In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as evolved UMTS terrestrial radio access (E-UTRA), which may use Long Term Evolution (LTE) and/or LTE-advanced (LTE-a) and/or LTE-advanced Pro (LTE-a Pro) to establish the air interface 116.

In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may use a new air interface (NR) to establish the air interface 116.

In embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, e.g., using a Dual Connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions sent to/from multiple types of base stations (e.g., enbs and gnbs).

In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., wireless fidelity (WiFi)), IEEE 802.16 (i.e., worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000 1X, CDMA EV-DO, tentative standard 2000 (IS-2000), tentative standard 95 (IS-95), tentative standard 856 (IS-856), global system for mobile communications (GSM), enhanced data rates for GSM evolution (EDGE), GSM EDGE (GERAN), and the like.

The base station 114B in fig. 1A may be, for example, a wireless router, a home Node B, a home eNode B, or an access point, and may utilize any suitable RAT to facilitate wireless connections in local areas such as businesses, homes, vehicles, campuses, industrial facilities, air corridors (e.g., for use by drones), roads, and the like. In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a Wireless Local Area Network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a Wireless Personal Area Network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-a Pro, NR, etc.) to establish a pico cell or femto cell. As shown in fig. 1A, the base station 114b may have a direct connection with the internet 110. Thus, the base station 114b may not need to access the Internet 110 via the CN 106/115.

The RANs 104/113 may communicate with the CNs 106/115, which may be any type of network configured to provide voice, data, application, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102 d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, delay requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106/115 may provide call control, billing services, mobile location based services, prepaid calls, internet connections, video distribution, etc., and/or perform advanced security functions such as user authentication. Although not shown in fig. 1A, it should be appreciated that the RANs 104/113 and/or CNs 106/115 may communicate directly or indirectly with other RANs that employ the same RAT as the RANs 104/113 or a different RAT. For example, in addition to being connected to the RAN 104/113 that may utilize NR radio technology, the CN 106/115 may also communicate with another RAN (not shown) employing GSM, UMTS, CDMA, wiMAX, E-UTRA, or WiFi radio technology.

The CN 106/115 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and/or other networks 112.PSTN 108 may include circuit-switched telephone networks that provide Plain Old Telephone Services (POTS). The internet 110 may include a global system for interconnecting computer networks and devices using common communication protocols, such as Transmission Control Protocol (TCP), user Datagram Protocol (UDP), and/or Internet Protocol (IP) in the TCP/IP internet protocol suite. Network 112 may include wired and/or wireless communication networks owned and/or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RANs 104/113 or a different RAT.

Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in fig. 1A may be configured to communicate with a base station 114a, which may employ a cellular-based radio technology, and with a base station 114b, which may employ an IEEE 802 radio technology.

Fig. 1B is a system diagram illustrating an exemplary WTRU 102. As shown in fig. 1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a Global Positioning System (GPS) chipset 136, and/or other peripheral devices 138, etc. It should be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a Digital Signal Processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, application Specific Integrated Circuits (ASICs), field Programmable Gate Arrays (FPGAs) circuits, any other type of Integrated Circuit (IC), a state machine, or the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functions that enable the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to a transceiver 120, which may be coupled to a transmit/receive element 122. Although fig. 1B depicts the processor 118 and the transceiver 120 as separate components, it should be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

The transmit/receive element 122 may be configured to transmit signals to and receive signals from a base station (e.g., base station 114 a) over the air interface 116. For example, in one embodiment, the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals. In one embodiment, the transmit/receive element 122 may be an emitter/detector configured to emit and/or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit/receive element 122 may be configured to transmit and/or receive RF and optical signals. It should be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.

Although the transmit/receive element 122 is depicted as a single element in fig. 1B, the WTRU 102 may include any number of transmit/receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

The transceiver 120 may be configured to modulate signals to be transmitted by the transmit/receive element 122 and demodulate signals received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, therefore, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs (such as NR and IEEE 802.11).

The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker/microphone 124, a keypad 126, and/or a display/touchpad 128, such as a Liquid Crystal Display (LCD) display unit or an Organic Light Emitting Diode (OLED) display unit. The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. Further, the processor 118 may access information from and store data in any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include Random Access Memory (RAM), read Only Memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 may include a Subscriber Identity Module (SIM) card, a memory stick, a Secure Digital (SD) memory card, and the like. In other embodiments, the processor 118 may never physically locate memory access information on the WTRU 102, such as on a server or home computer (not shown), and store the data in that memory.

The processor 118 may receive power from the power source 134 and may be configured to distribute and/or control power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry battery packs (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114 b) over the air interface 116 and/or determine its location based on the timing of signals received from two or more nearby base stations. It should be appreciated that the WTRU 102 may obtain location information by any suitable location determination method while remaining consistent with an embodiment.

The processor 118 may also be coupled to other peripheral devices 138, which may include providingAdditional features, functionality, and/or one or more software modules and/or hardware modules that are wired or wirelessly connected. For example, the number of the cells to be processed, peripheral devices 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photographs and/or video), universal Serial Bus (USB) ports, vibrating devices, television transceivers, hands-free headsets, wireless communications devices, and the like,Modules, frequency Modulation (FM) radio units, digital music players, media players, video game player modules, internet browsers, virtual reality and/or augmented reality (VR/AR) devices, activity trackers, and the like. The peripheral device 138 may include one or more sensors, which may be one or more of the following: gyroscopes, accelerometers, hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors; a geographic position sensor; altimeters, light sensors, touch sensors, magnetometers, barometers, gesture sensors, biometric sensors, and/or humidity sensors.

WTRU 102 may include a full duplex radio for which transmission and reception of some or all signals (e.g., associated with a particular subframe for UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and/or simultaneous. The full duplex radio station may include an interference management unit for reducing and/or substantially eliminating self-interference via hardware (e.g., choke) or via signal processing by a processor (e.g., a separate processor (not shown) or via processor 118). In one embodiment, WRTU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with a particular subframe for UL (e.g., for transmission) or downlink (e.g., for reception)).

Fig. 1C is a system diagram illustrating a RAN 104 and a CN 106 according to one embodiment. As noted above, the RAN 104 may communicate with the WTRUs 102a, 102b, 102c over the air interface 116 using an E-UTRA radio technology. RAN 104 may also communicate with CN 106.

RAN 104 may include eNode bs 160a, 160B, 160c, but it should be understood that RAN 104 may include any number of eNode bs while remaining consistent with an embodiment. eNode bs 160a, 160B, 160c may each include one or more transceivers to communicate with WTRUs 102a, 102B, 102c over air interface 116. In an embodiment, eNode bs 160a, 160B, 160c may implement MIMO technology. Thus, eNode B160a may use multiple antennas to transmit wireless signals to WTRU 102a and/or receive wireless signals from WTRU 102a, for example.

each of eNode bs 160a, 160B, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and/or DL, and the like. As shown in fig. 1C, eNode bs 160a, 160B, 160C may communicate with each other through an X2 interface.

The CN 106 shown in fig. 1C may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) gateway (or PGW) 166. While each of the foregoing elements are shown as part of the CN 106, it should be understood that any of these elements may be owned and/or operated by an entity other than the CN operator.

MME 162 may be connected to each of eNode bs 162a, 162B, 162c in RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating the user of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, and the like. MME 162 may provide control plane functionality for switching between RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and/or WCDMA.

SGW 164 may be connected to each of eNode bs 160a, 160B, 160c in RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102 c. SGW 164 may perform other functions such as anchoring user planes during inter-eNode B handover, triggering paging when DL data is available to WTRUs 102a, 102B, 102c, managing and storing contexts of WTRUs 102a, 102B, 102c, and the like.

The SGW 164 may be connected to a PGW 166 that may provide the WTRUs 102a, 102b, 102c with access to a packet switched network, such as the internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to a circuit-switched network (such as the PSTN 108) to facilitate communications between the WTRUs 102a, 102b, 102c and legacy landline communication devices. For example, the CN 106 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and/or wireless networks owned and/or operated by other service providers.

Although the WTRU is depicted in fig. 1A-1D as a wireless terminal, it is contemplated that in some representative embodiments such a terminal may use a wired communication interface with a communication network (e.g., temporarily or permanently).

In representative embodiments, the other network 112 may be a WLAN.

A WLAN in an infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more Stations (STAs) associated with the AP. The AP may have access or interface to a Distribution System (DS) or another type of wired/wireless network that carries traffic to and/or from the BSS. Traffic originating outside the BSS and directed to the STA may arrive through the AP and may be delivered to the STA. Traffic originating from the STA and leading to a destination outside the BSS may be sent to the AP to be delivered to the respective destination. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may pass the traffic to the destination STA. Traffic between STAs within a BSS may be considered and/or referred to as point-to-point traffic. Point-to-point traffic may be sent between (e.g., directly between) the source and destination STAs using Direct Link Setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z Tunnel DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs (e.g., all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad-hoc" communication mode.

When using the 802.11ac infrastructure mode of operation or similar modes of operation, the AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20MHz wide bandwidth) or a width dynamically set by signaling. The primary channel may be an operating channel of the BSS and may be used by STAs to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access/collision avoidance (CSMA/CA) may be implemented, for example, in an 802.11 system. For CSMA/CA, STAs (e.g., each STA), including the AP, may listen to the primary channel. If the primary channel is listened to/detected by a particular STA and/or determined to be busy, the particular STA may backoff. One STA (e.g., only one station) may transmit at any given time in a given BSS.

High Throughput (HT) STAs may communicate using 40MHz wide channels, for example, via a combination of a primary 20MHz channel with an adjacent or non-adjacent 20MHz channel to form a 40MHz wide channel.

Very High Throughput (VHT) STAs may support channels that are 20MHz, 40MHz, 80MHz, and/or 160MHz wide. 40MHz and/or 80MHz channels may be formed by combining consecutive 20MHz channels. The 160MHz channel may be formed by combining 8 consecutive 20MHz channels, or by combining two non-consecutive 80MHz channels (this may be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, the data may pass through a segment parser that may split the data into two streams. An Inverse Fast Fourier Transform (IFFT) process and a time domain process may be performed on each stream separately. These streams may be mapped to two 80MHz channels and data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed and the combined data may be sent to a Medium Access Control (MAC).

The 802.11af and 802.11ah support modes of operation below 1 GHz. Channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11 ac. The 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the television white space (TVWS) spectrum, and the 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah may support meter type control/machine type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including supporting (e.g., supporting only) certain bandwidths and/or limited bandwidths. MTC devices may include batteries with battery lives above a threshold (e.g., to maintain very long battery lives).

WLAN systems that can support multiple channels, and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and/or limited by STAs from all STAs operating in the BSS (which support a minimum bandwidth mode of operation). In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only) 1MHz mode, the primary channel may be 1MHz wide, even though the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and/or other channel bandwidth modes of operation. The carrier sense and/or Network Allocation Vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because the STA (supporting only 1MHz mode of operation) is transmitting to the AP, the entire available frequency band may be considered busy even though most of the frequency band remains idle and possibly available.

The available frequency band for 802.11ah in the united states is 902MHz to 928MHz. In korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

Fig. 1D is a system diagram illustrating RAN 113 and CN 115 according to one embodiment. As noted above, RAN 113 may employ NR radio technology to communicate with WTRUs 102a, 102b, 102c over an air interface 116. RAN 113 may also communicate with CN 115.

RAN 113 may include gnbs 180a, 180b, 180c, but it should be understood that RAN 113 may include any number of gnbs while remaining consistent with an embodiment. Each of the gnbs 180a, 180b, 180c may include one or more transceivers to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gnbs 180a, 180b, 180c may implement MIMO technology. For example, gnbs 180a, 108b may utilize beamforming to transmit signals to and/or receive signals from gnbs 180a, 180b, 180 c. Thus, the gNB 180a may use multiple antennas to transmit wireless signals to the WTRU 102a and/or receive wireless signals from the WTRU 102a, for example. In an embodiment, the gnbs 180a, 180b, 180c may implement carrier aggregation techniques. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on the unlicensed spectrum while the remaining component carriers may be on the licensed spectrum. In embodiments, the gnbs 180a, 180b, 180c may implement coordinated multipoint (CoMP) techniques. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and/or gNB 180 c).

The WTRUs 102a, 102b, 102c may communicate with the gnbs 180a, 180b, 180c using transmissions associated with the scalable parameter sets. For example, the OFDM symbol interval and/or OFDM subcarrier interval may vary from one transmission to another, from one cell to another, and/or from one portion of the wireless transmission spectrum to another. The WTRUs 102a, 102b, 102c may communicate with the gnbs 180a, 180b, 180c using various or scalable length subframes or Transmission Time Intervals (TTIs) (e.g., including different numbers of OFDM symbols and/or continuously varying absolute time lengths).

The gnbs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in an independent configuration and/or in a non-independent configuration. In a stand-alone configuration, the WTRUs 102a, 102B, 102c may communicate with the gnbs 180a, 180B, 180c while also not accessing other RANs (e.g., such as the eNode bs 160a, 160B, 160 c). In an independent configuration, the WTRUs 102a, 102b, 102c may use one or more of the gnbs 180a, 180b, 180c as mobility anchor points. In an independent configuration, the WTRUs 102a, 102b, 102c may use signals in unlicensed frequency bands to communicate with the gnbs 180a, 180b, 180 c. In a non-standalone configuration, the WTRUs 102a, 102B, 102c may communicate or connect with the gnbs 180a, 180B, 180c while also communicating or connecting with other RANs (such as eNode bs 160a, 160B, 160 c). For example, the WTRUs 102a, 102B, 102c may implement DC principles to communicate with one or more gnbs 180a, 180B, 180c and one or more eNode bs 160a, 160B, 160c substantially simultaneously. In a non-standalone configuration, the eNode bs 160a, 160B, 160c may serve as mobility anchors for the WTRUs 102a, 102B, 102c, and the gnbs 180a, 180B, 180c may provide additional coverage and/or throughput for serving the WTRUs 102a, 102B, 102 c.

Each of the gnbs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and/or DL, support of network slices, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards User Plane Functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, and so on. As shown in fig. 1D, gnbs 180a, 180b, 180c may communicate with each other through an Xn interface.

The CN 115 shown in fig. 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it should be understood that any of these elements may be owned and/or operated by an entity other than the CN operator.

AMFs 182a, 182b may be connected to one or more of gNB 180a, 180b, 180c in RAN 113 via an N2 interface and may function as a control node. For example, the AMFs 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slices (e.g., handling of different PDU sessions with different requirements), selection of a particular SMF 183a, 183b, management of registration areas, termination of NAS signaling, mobility management, etc. The AMFs 182a, 182b may use network slices to customize CN support for the WTRUs 102a, 102b, 102c based on the type of service used by the WTRUs 102a, 102b, 102 c. For example, different network slices may be established for different use cases, such as services relying on ultra high reliability low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, services for Machine Type Communication (MTC) access, and so on. AMF 162 may provide control plane functionality for switching between RAN 113 and other RANs (not shown) employing other radio technologies, such as LTE, LTE-A, LTE-a Pro, and/or non-3 GPP access technologies, such as WiFi.

The SMFs 183a, 183b may be connected to AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to UPFs 184a, 184b in the CN 115 via an N4 interface. SMFs 183a, 183b may select and control UPFs 184a, 184b and configure traffic routing through UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions such as managing and assigning UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, etc. The PDU session type may be IP-based, non-IP-based, ethernet-based, etc.

UPFs 184a, 184b may be connected to one or more of the gnbs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to a packet-switched network, such as the internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. UPFs 184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-host PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

The CN 115 may facilitate communications with other networks. For example, the CN 115 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and/or wireless networks owned and/or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may connect to the local Data Networks (DNs) 185a, 185b through the UPFs 184a, 184b through an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

In view of fig. 1A-1D and the corresponding descriptions of fig. 1A-1D, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more emulation devices (not shown): WTRUs 102a-d, base stations 114a-B, eNode bs 160a-c, MME 162, SGW 164, PGW 166, gnbs 180a-c, AMFs 182a-B, UPFs 184a-B, SMFs 183a-B, DNs 185a-B, and/or any other devices described herein. The emulated device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation device may be used to test other devices and/or analog network and/or WTRU functions.

The simulation device may be designed to enable one or more tests of other devices in a laboratory environment and/or an operator network environment. For example, the one or more emulation devices can perform one or more or all of the functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices can perform one or more functions or all functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The emulation device may be directly coupled to another device for testing purposes and/or may perform testing using over-the-air wireless communications.

The one or more emulation devices can perform one or more (including all) functions while not being implemented/deployed as part of a wired and/or wireless communication network. For example, the simulation device may be used in a test laboratory and/or a test scenario in a non-deployed (e.g., test) wired and/or wireless communication network in order to enable testing of one or more components. The one or more simulation devices may be test equipment. Direct RF coupling and/or wireless communication via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation device to transmit and/or receive data.

Systems, methods, and tools for a wireless transmit/receive unit (WTRU) configured to save power during active times are described herein. The WTRU may be configured to interpret one or more power saving bits in Downlink Control Information (DCI) (e.g., an indication of a search space group switch and/or a Physical Downlink Control Channel (PDCCH) skip), e.g., based on WTRU status. The WTRU may be configured to receive DCI via a PDCCH transmission. The DCI may include one or more power saving bits. The one or more power saving bits may include a power saving indication. The WTRU may determine a power saving action to be performed by the WTRU based on the power saving indication.

The WTRU may be configured to switch from the first search space group to the second search space group and monitor downlink transmissions in accordance with the second search space group, for example, when the WTRU determines that the power saving action to be performed is to switch to the second search space group.

The WTRU may be configured to skip monitoring downlink transmissions according to the first set of search spaces, for example, when the WTRU determines that the power saving action to be performed is to skip monitoring downlink transmissions.

The WTRU may be configured to process retransmission and scheduling request processing when the WTRU receives a PDCCH skip request. Based on the received PDCCH scheduling request, the WTRU may not perform PDCCH skipping or may monitor the PDCCH according to a reduced set of search spaces in the time window. Based on the received PDCCH request, the WTRU may refrain from performing PDCCH skipping in the time interval. For example, the time interval may be determined by one or more retransmission timers. The WTRU may be configured to determine the code point interpretation using parameters of the RRC configuration. The WTRU may be configured to terminate PDCCH skipping after SR transmission. The WTRU may be configured to indicate PDCCH monitoring for one or more secondary cells (scells).

For example, discontinuous Reception (DRX) may be used to conserve battery power. For example, during DRX, the WTRU may not monitor a Downlink (DL) control channel, e.g., a Physical Downlink Control Channel (PDCCH). The WTRU may use connected mode DRX (C-DRX), for example, in a Radio Resource Control (RRC) connected mode. An example of DRX is shown in fig. 2.

Fig. 2 is a diagram illustrating an example of on-duration and off-duration in a DRX cycle (e.g., to conserve battery power). The WTRU may monitor (e.g., configured) a channel (e.g., PDCCH) during the on duration and may sleep (e.g., not monitor PDCCH) during the off duration. PDCCH is a non-limiting example of a channel (e.g., control channel) that may or may not be monitored during a cycle. In an example, channel and PDCCH may be used interchangeably.

The DRX cycle may be a cycle of on duration and off duration (e.g., with aperiodic repetition or periodic repetition). The WTRU may monitor a channel (e.g., one or more channels, such as PDCCH) during the on duration and may skip monitoring a channel (e.g., one or more channels, such as PDCCH) during the off duration. The on-duration and DRX on-duration are used interchangeably herein. The off duration and DRX off duration are used interchangeably herein.

In an example, the DRX cycle may be a short DRX cycle or a long DRX cycle. The WTRU may use a short DRX cycle for a period of time and/or a long DRX cycle for a period of time.

Reference herein to a timer may refer to a determination of time or a determination of a period of time. References herein to expiration of a timer may refer to determining that a time has occurred or that a time period has expired. References herein to timers may refer to time, time periods, tracking time periods, and the like. Reference herein to a timer may refer to determining that a time has occurred or that a period of time has ended.

Time, time period, etc. (e.g., based on time slot duration) may be determined. The time may be a time after a PDCCH occasion, where a PDCCH (e.g., a successfully decoded PDCCH) may indicate (e.g., initiate) an Uplink (UL) or DL user data transmission. The DRX inactivity timer may indicate or may be used to determine time. For example, a DRX inactivity timer may be used to determine whether and/or when to transition to the off duration. The DRX inactivity timer and inactivity timer are used interchangeably herein.

The DRX on duration may be a duration at the beginning of a DRX cycle.

The number of PDCCH occasions (e.g., consecutive PDCCH occasions) may be determined. The number of PDCCH occasions may be determined using an on duration (e.g., an on duration timer). The number of PDCCH occasions determined may be, for example, the number of PDCCH occasions that may be required (e.g., by the WTRU) to be monitored or decoded after waking up from the DRX cycle and/or at the beginning of the DRX cycle.

The PDCCH occasion may be a period of time that may include PDCCH transmission, e.g., the PDCCH occasion may be a symbol, a set of symbols, a slot, or a subframe.

For example, if the WTRU may desire retransmission, a DRX retransmission timer may be used to determine the number of PDCCH occasions to monitor (e.g., the number of consecutive). The DRX retransmission timer may be used to determine (e.g., may determine) a duration until a DL retransmission is received (e.g., a maximum duration) and/or a duration until a UL retransmission grant is received (e.g., a maximum duration).

The DRX short cycle may be a first DRX cycle that the WTRU enters, for example, after the DRX inactivity timer expires. The WTRU may be in a short DRX cycle, for example, until the DRX short cycle timer expires. For example, if the DRX short cycle timer expires, the WTRU may use a long DRX cycle.

The DRX short cycle timer may be used to determine (e.g., may determine) the number of subframes (e.g., the number of consecutive) after the DRX short cycle (e.g., after the DRX inactivity timer has expired).

For example, during the active time, the WTRU may monitor PDCCH and/or PDCCH occasions. The active time may occur, for example, during an on duration. The active time may occur, for example, during the off duration. In an example, the active time may begin during the on duration and may continue during the off duration. The active time and the active time of the DRX cycle are used interchangeably herein.

The activity time may include, for example, a time when at least one of the following is true: (i) The DRX timer is running, for example, where the DRX timer may be an on duration timer, an inactivity timer, a retransmission timer (e.g., in DL and/or UL retransmissions), and/or a random access contention resolution timer; (ii) A scheduling request (e.g., on a Physical Uplink Control Channel (PUCCH)) is sent and may be pending; (iii) Or that a PDCCH transmission has not been received (e.g., a new transmission indicating a cell radio network temporary identifier (C-RNTI) of a Medium Access Control (MAC) entity addressed to the WTRU) (e.g., after successful receipt of a random access response to a random access preamble not selected by the MAC entity among contention-based random access preambles).

The DRX timer may be a timer associated with DRX. In an example, one or more of the following timers may be associated with DRX: a DRX on duration timer (e.g., DRX-onduration timer); a DRX inactivity timer (e.g., DRX-inactivity timer); DRX DL retransmission timer (e.g., DRX-retransmission TimerDL); DRX UL retransmission timer (e.g., DRX-retransmission timer UL); a DRX hybrid automatic repeat request (HARQ) Round Trip Time (RTT) timer of the UL (e.g., DRX-HARQ-RTT-TimerUL); or DRX HARQ RTT timer of DL (e.g., DRX-HARQ-RTT-TimerDL).

The DRX inactivity timer may be a duration after a PDCCH occasion, e.g., where the PDCCH transmission indicates an initial UL or DL user data transmission of the MAC entity. The DRX DL retransmission timer (e.g., per DL HARQ process) may be, for example, a duration (e.g., a maximum duration) until a DL retransmission is received. The DRX UL retransmission timer (e.g., per UL HARQ process) may be, for example, a duration (e.g., a maximum duration) until a grant of UL retransmission is received. The DRX HARQ RTT timer of the UL (e.g., per UL HARQ process) may be, for example, a duration (e.g., a minimum duration) before the WTRU or MAC entity may expect UL HARQ retransmission grants. The DRX HARQ RTT timer for DL (e.g., per DL HARQ process) may be, for example, a duration (e.g., a minimum duration) before DL allocation for which the WTRU or MAC entity may expect HARQ retransmissions.

The wake-up signal (WUS) and/or the sleep-on signal (GOS) (WUS/GOS) may be used, for example, with DRX operation. WUS/GOS may be associated with one or more DRX cycles. WUS/GOS may be transmitted and/or received, for example, prior to an associated time or portion of a DRX cycle (e.g., an associated DRX cycle).

Fig. 3 is a diagram illustrating an example of WUS and GOS used with a DRX operation. For example, if the WTRU receives a wake-up indication, the WTRU may monitor PDCCH transmissions for an on duration of one or more DRX cycles. For example, if the WTRU receives a sleep or non-wake indication, the WTRU may skip monitoring PDCCH transmissions for the on duration of one or more DRX cycles and may stay in a sleep mode (e.g., deep sleep mode).

The WTRU may be configured to monitor Downlink Control Information (DCI) (e.g., DCI format 2_6), for example, in a common search space. For example, the WTRU may be configured to monitor downlink control information in the common search space prior to the on duration. The WTRU may receive an indication (e.g., a 1-bit flag, such as ps-wakeup) for example, to indicate whether the WTRU may initiate the active time of the next DRX cycle (e.g., indicated by DRX-onduration timer). For example, if the WTRU is not set with an indication (e.g., a 1-bit flag such as ps-wakeup), the WTRU may not initiate the active time of the next DRX cycle (e.g., indicated by DRX-onduration timer).

A New Radio (NR) PDCCH and search space may be provided (e.g., implemented). In an example, the Resource Element Group (REG) may be a building block (e.g., a minimum building block) of the PDCCH. The REGs may include 12 Resource Elements (REs) over the OFDM symbol in time and Resource Blocks (RBs) over frequency. In REG, nine (9) Resource Elements (REs) may be used for control information, and three (3) REs may be used for demodulation reference signals (DM-RS). Multiple (e.g., 2, 3, or 6) REGs (e.g., REGs that may be adjacent in time or frequency) may form a REG bundle. The REG bundles may be used, for example, with precoders (e.g., the same precoder). DM-RS of multiple REGs in the REG bundle may be used for channel estimation. In an example, six (6) REGs (e.g., in a format of 1, 2, or 3 REG bundles) may form a Control Channel Element (CCE). The CCE may be the smallest possible PDCCH. The PDCCH may include one or more CCEs (e.g., 1, 2, 4, 8, or 16 CCEs). The number of CCEs associated with a PDCCH may be referred to as an Aggregation Level (AL) of the PDCCH.

The REG bundles may be mapped (e.g., using interleaved or non-interleaved mapping). In an example (e.g., for non-interleaving mapping), consecutive REG bundles (e.g., adjacent in frequency) may form CCEs. CCEs adjacent in frequency may form a PDCCH. In an example (e.g., using interleaving mapping), REGs may be interleaved (e.g., and/or permuted) e.g., before being mapped to CCEs, which may result in (e.g., typically) non-adjacent REG bundles in (e.g., one) CCE and non-adjacent CCEs in (e.g., one) PDCCH.

A control resource set (CORESET) may be configured. CORESET may comprise at least one of: (i) Frequency allocation (e.g., as a plurality of RBs such as a block of 6 RBs); (ii) A length of time (e.g., one or more, such as 1-3 OFDM symbols); (iii) type of REG bundle; or (iv) the type of mapping from REG bundles to CCEs (e.g., interleaved mapping or non-interleaved mapping). In the bandwidth part (BWP), there may be up to N (e.g., 3) corefets. For example, there may be 12 CORESETs in four (4) possible bandwidth portions.

The WTRU may monitor for a set of PDCCH candidates or may be assigned a set of PDCCH candidates (e.g., for monitoring). A set of PDCCH candidates may be monitored, for example, during blind detection of the PDCCH. The search space or set of search spaces (e.g., for multiple aggregation levels) may be or may include a set of PDCCH candidates (e.g., for monitoring (such as with blind detection)). The search space, each search space, or set of search spaces may be configured, for example, by at least one of: (i) an associated CORESET; (ii) For each aggregation level or number of candidates within each aggregation level; or (iii) a set of monitoring opportunities. The monitoring occasion may be determined, for example, by one or more of the following: monitoring periodicity (e.g., from time slot), monitoring offset, or monitoring pattern (e.g., having a plurality of bits (e.g., 14 bits) corresponding to possible symbol patterns within a time slot).

The function that may facilitate WTRU power consumption may be control channel monitoring during active times (e.g., for control channels such as PDCCH and side chain control channels). The WTRU may wake up and perform one or more processes (e.g., channel estimation, channel decoding, demodulation, etc.), for example, to detect one or more PDCCH monitoring candidates in a PDCCH monitoring occasion. Such procedures (e.g., performed by the WTRU) may result in power consumption, which may increase, for example, if the procedure is performed frequently (e.g., per slot) and/or if the number of PDCCH candidates is large. For example, the WTRU may be enabled (e.g., configured) to save power (e.g., battery power) while monitoring for control channel candidates.

The WTRU may reduce PDCCH monitoring, for example, by: (i) Skip monitoring PDCCH transmissions (e.g., not monitoring PDCCH transmissions in one or more time instances according to a set of search spaces), and/or (ii) switch between different sets of search spaces, e.g., based on traffic conditions. One or more features may be provided that may be used to reduce PDCCH monitoring by skipping PDCCH monitoring and switching groups of search spaces. PDCCH monitoring skip and PDCCH skip are used interchangeably herein.

A state may be defined as a set of conditions that a WTRU may apply or may be in, for example, while PDCCH transmissions are being monitored. For example, the definition of the state may include a set of search spaces (e.g., a set of search spaces), which may be the set of search spaces upon which the WTRU monitors PDCCH transmissions. Search Spaces (SSs) that may be configured for bandwidth parts (BWP) may be grouped into two groups, such as SS group #0 and SS group #1. If the WTRU monitors PDCCH transmissions from SS group #0, the WTRU may be said to be in a first state (e.g., state 0). If the WTRU monitors PDCCH transmissions from SS group #1, the WTRU may be said to be in a second state (e.g., state 1). The number of state and search space groups is not limited to two, and the examples provided herein may be used for illustration purposes.

The state may be (or may be said to be) associated with a subset of the set of search spaces (e.g., one set of search spaces). For example, if the WTRU is in one state, the WTRU may be expected to monitor PDCCH transmissions, e.g., according to a relevant subset of the search space group. The state associated with the empty set of SSs may be referred to as an empty state. If the WTRU is in a null state, the WTRU may not monitor PDCCH transmissions (e.g., only monitor one or more common search spaces and not monitor WTRU-specific search spaces). One SS may be included in more than one SS group. One SS may be associated with more than one state. The null state may not be associated with a WTRU-specific SS (e.g., any WTRU-specific SS). The null state may be associated with at least one common SS.

The state transition from the first state to the second state may be or may include a switch from a first SS group associated with the first state to a second SS group associated with the second state. Switching from the first SS group to the second SS group may mean that the WTRU stops monitoring PDCCH transmissions according to SSs in the first SS group and starts monitoring PDCCH transmissions according to SSs in the second group. State transitions and SS group handoffs are used interchangeably.

A WTRU that may be in one state may receive an indication (e.g., explicitly or implicitly) that PDCCH transmissions are not to be monitored (e.g., allowed to skip monitoring PDCCH transmissions during a time interval). The duration of the time interval may be measured in terms of absolute time (e.g., in ms), time slots, OFDM symbols, number of monitoring occasions, and so on. The description herein of the duration of the time interval is not limited to the units of time interval measurement used in the description, and may be applied to any suitable unit of time interval measurement (e.g., all units of time measurement described herein).

The state transition may be triggered by an explicit or implicit indication. In an example, the explicit indication may be signaled in control information (e.g., DCI) in the PDCCH transmission and/or via MAC signaling (e.g., with a MAC Control Element (CE)). For example, the implicit indication may be triggered by receiving a transmission on a channel such as PDCCH. Expiration of a timer may trigger a state transition.

The WTRU state (e.g., each state) may be associated with a timer. For example, if the WTRU enters this state, a timer may be started or restarted. The WTRU may exit the state, for example, in response to expiration of a timer. In response to expiration of the timer, the WTRU may transition to a state (e.g., a new state), which may be a previous state in which the WTRU is located, a preconfigured state (e.g., a null state or a default state), or a state that may be determined using certain rules.

The timers of the states may be configured (e.g., independently) and/or determined (e.g., independently). For example, a first timer may be used in a first state and a second timer may be used in a second state, e.g., where the first timer and the second timer are different.

The timer may be used or applied to a subset of the states. For example, no timer may be used for a first state in the set of states (e.g., state 0), and a timer may be used for states other than the first state in the set of states.

Unified SS handover and PDCCH monitoring skip indication may be implemented.

The WTRU may be configured with at least one control information format (e.g., DCI or a format for other types of control information). At least one bit may be provided in control information (e.g., DCI). For example, at least one of DCI formats 1_0, 1_1, 0_0, 0_1, 2_2, 2_6, etc. may be used for unified SS handover and PDCCH monitoring skip indication, for example. These bits may be referred to herein as power save bits or PS bits. The PS bit may indicate to the WTRU to trigger a state transition (e.g., SS group switch, such as monitoring downlink control information transmissions (e.g., PDCCH transmissions) in a different SS group) and/or may indicate to the WTRU to perform PDCCH monitoring skip (e.g., skip monitoring downlink control information transmissions (e.g., PDCCH transmissions) in a current SS group). The PS bit may indicate to the WTRU to stay in a current state (e.g., the current state is the state in which the WTRU was when the WTRU received the DCI, where stay in the current state may mean monitoring downlink control information transmissions (e.g., PDCCH transmissions)) in the current SS group and/or not performing PDCCH monitoring skips (e.g., continuing to monitor downlink control information transmissions (e.g., PDCCH transmissions) in the current SS group).

The PS bits may indicate to the WTRU to perform one or more of the following actions (e.g., in the case where PS bits are received while the WTRU is in the first state): (i) Move to another state (e.g., trigger a state transition); (ii) stay in the current state; (iii) performing PDCCH skipping according to a pre-configuration; (iv) not performing PDCCH skipping; or (v) a state transition and PDCCH skipping, such as the WTRU may perform PDCCH skipping and move to another state, or the WTRU may move to another state and perform PDCCH skipping. The actions described herein may be implicitly indicated/triggered (e.g., based on expiration of time).

In an example, the PS bit may indicate to the WTRU to perform an action related to a state transition (e.g., whether to move to another state or stay in the current state) and/or an action related to PDCCH skipping (e.g., whether to perform PDCCH skipping). The WTRU may determine the appropriate action to perform. For example, the DCI (e.g., DCI received by the WTRU) may include a single PS bit. The WTRU may determine that the PS bit indicates to perform an action related to a state transition. The WTRU may be in state 0. If the WTRU receives bit 0, the WTRU may stay in state 0. If the WTRU receives bit 1, the WTRU may move to state 1. The WTRU may be in state 1. If the WTRU receives bit 1, the WTRU may stay in state 1. If the WTRU receives bit 0, the WTRU may move to state 0.

The WTRU may determine that PS bits indicate to perform actions related to PDCCH skipping in the current state. If the WTRU receives bit 0, the WTRU may stay in the current state and not perform PDCCH skip. If the WTRU receives bit 1, the WTRU may stay in the current state and perform PDCCH skipping.

The WTRU may be configured with one or more parameters associated with the action indicated by the PS bit. In an example, the WTRU may be configured with a possible skip duration, e.g., to perform actions related to PDCCH skipping. For example, in the case of using two bits (e.g., PS bits), the WTRU may be instructed to: 00: not skip; 01: skipping N time slots; 10: skipping M time slots; or 11: skipping until the DRX cycle ends. If a null state is defined, PDCCH skipping may be implemented, for example, by indicating to the WTRU to move to the null state and stay in the null state for a duration (e.g., a particular duration).

As a result of receiving PS bits, the WTRU may use factors to determine appropriate actions (e.g., actions related to state transitions or PDCCH skips). These factors may include the state, configuration, parameters, etc. that the WTRU is in when it receives DCI (e.g., DCI containing PS bits). Factors may include the state the WTRU is in when DCI is received. In an example, in some states, PS bits may indicate actions related to PDCCH skipping. In other states, the PS bit may indicate actions related to SS group handover.

Fig. 4 is a diagram illustrating an example of a state transition of a WTRU based on PS bit indication and/or timer expiration. In this example, the WTRU may be configured with two states (e.g., 00 and 01) and/or a DCI format with one or more PS bits. For example, in the case of receiving PS bits (e.g., if the WTRU is in state 00), it may be determined (e.g., by the WTRU) that the PS bits trigger actions related to the state transition. For example, in the case of receiving PS bits (e.g., if the WTRU is in state 01), it may be determined (e.g., by the WTRU) that PS bits trigger actions related to PDCCH skipping.

If the WTRU is in state 00, the WTRU may behave as follows. For example, if the WTRU is in state 00, the WTRU may monitor PDCCH transmissions according to SS group # 0. If the WTRU receives a DCI format configured with PS bits and the PS bits indicate to the WTRU to stay in the current state (e.g., monitor PDCCH transmissions according to SS group #0 and PS bits are 0 (e.g., PS bits: 0)), the WTRU may monitor PDCCH transmissions according to SS group # 0. If the WTRU is in state 00, the WTRU may monitor PDCCH transmissions according to SS group # 0. If the WTRU receives a DCI format configured with PS bits and the PS bits (e.g., to the WTRU) indicate a transition to state 01 (e.g., monitoring PDCCH transmissions according to SS group #1 and PS bits are 1 (e.g., PS bits: 1)), the WTRU may transition to state 01 (e.g., the WTRU may begin monitoring PDCCH transmissions according to SS group # 1). If the WTRU enters state 01, the WTRU may start a timer.

If the WTRU is in state 01, the WTRU may behave as follows. For example, if the WTRU is in state 01, the WTRU may monitor PDCCH transmissions according to SS group # 1. If the WTRU receives a DCI format configured with PS bits and the PS bits are set to 0, the WTRU may monitor PDCCH transmissions according to SS group # 1.

If the WTRU is in state 01, the WTRU may monitor PDCCH transmissions according to SS group # 1. If the WTRU receives a DCI format configured with PS bits and the PS bits are set to 1, the WTRU may skip monitoring PDCCH transmissions for a duration (e.g., a particular duration). The duration may be preconfigured.

The WTRU may transition from state 01 to state 00, for example, in response to expiration of a timer (e.g., a timer associated with state (e.g., state 01)). For example, if the WTRU receives a PDCCH transmission (e.g., a PDCCH transmission with a grant for a transport block (e.g., a new transport block) or DCI with a priority indicator (e.g., priority indicator=0)), the timer may restart. The states (e.g., each state) may be configured with a timer. The timer may be activated, for example, with MAC CE and/or DCI. Activation of the timer may mean that the WTRU is about to use the timer. In an example, the timer may be started and/or restarted in response to an action (e.g., if the WTRU enters a state corresponding to the timer). If the timer expires, the WTRU may perform actions (e.g., the necessary actions). An inactive timer may mean that the timer is not used.

Whether a transition from one state to another state is triggered (e.g., implemented) by explicit signaling (e.g., via DCI) and/or implicit signaling (e.g., in response to receiving a PDCCH transmission) and/or another method (e.g., expiration of a timer) may be configured and/or specified by rules. For example, in fig. 4, the transition from state 00 to state 01 may be triggered (e.g., implemented) by the DCI. The transition from state 01 to state 00 may be triggered (e.g., implemented) by expiration of a timer. If the DCI is not configured with PS bits, the transition from state 00 to state 01 may be triggered (e.g., implemented) by the implicit methods described herein (e.g., the WTRU receives a PDCCH transmission).

Fig. 5 is a diagram illustrating an example of using a null state for PDCCH skipping. As shown in fig. 5, if in the null state, the WTRU may not be expected to monitor for PDCCH transmissions (e.g., if in the null state, the WTRU may not receive an indication within the DCI).

Fig. 6 is a diagram showing an example of more than two states including an empty state. As shown in fig. 6, state transitions may be limited to certain cases (e.g., only certain cases), and these transitions may be triggered by explicit or implicit signaling. The same bit in different states may trigger different transitions. For example, in state 00, bit 1 may indicate a transition to state 01; and in state 01, bit 1 may indicate a transition to state 10. May transition from state 10 to state 00, state 01, or another state as described herein. From one state, the WTRU may be configured with and/or may determine a set of states to which the WTRU may move. As shown in fig. 6, the WTRU may move from state 00 to state 01 (e.g., only state 01). If the WTRU may move to more than one state, more than one bit may be used.

Fig. 7 is a diagram showing an example of state transition based on implicit indication. As shown in fig. 7, SS group handover may be triggered by implicit signaling and/or expiration of a timer. PDCCH skipping may be triggered with PS bits.

If the WTRU is in state 00, the WTRU may behave as follows. For example, if the WTRU is in state 00, the WTRU may monitor PDCCH transmissions according to SS group # 0. If the WTRU receives a PDCCH transmission, the WTRU may perform a transition to state 01. A timer may be started.

If the WTRU is in state 01, the WTRU may behave as follows. For example, if the WTRU is in state 01, the WTRU may monitor PDCCH transmissions according to SS group # 1. If the WTRU receives a DCI format configured with PS bits (e.g., PS: 0), the WTRU may monitor PDCCH transmissions according to SS group # 1. For example, if the WTRU is in state 01, the WTRU may monitor PDCCH transmissions according to SS group # 1. If the WTRU receives a DCI format configured with PS bits (e.g., PS: 1), the WTRU may skip monitoring PDCCH transmissions for a duration (e.g., a particular duration). The duration may be preconfigured. The WTRU may exit state 01 in response to the timer expiring.

In an example, the WTRU may switch to SS group 1 in response to the DRX on duration timer starting. The WTRU may monitor PDCCH transmissions according to SS group 1, e.g., during an on duration. For example, if the WTRU is in this state (e.g., state 1), the WTRU may start an associated timer. The WTRU may start or restart an associated timer if the WTRU receives a PDCCH transmission before the on duration expires. The WTRU may move to state 0 if the associated timer expires. If a PDCCH transmission is received while the WTRU is in state 0, the WTRU may transition to state 1 and may start an associated timer. If a DCI bit is received, the DCI bit may indicate a skip.

In an example, SS group switching and/or PDCCH skipping may be indicated by one or more of the following. SS group switching and/or PDCCH skipping may be indicated by a number of states (e.g., a number of configured SS groups). If one (e.g., only one) group is configured, the PS bit may indicate an action related to PDCCH skipping. For example, a 0 may indicate no skip; and 1 may indicate skip. SS group switching and/or PDCCH skipping may be indicated by CORESET. For example, a bit in a DCI/PDCCH transmission received in the first CORESET (e.g., a DCI in a PDCCH transmission) may indicate an action related to PDCCH skipping. For example, a bit in a DCI/PDCCH transmission received in the second CORESET may indicate an action related to SS handover. SS group switching and/or PDCCH skipping may be indicated by the WTRU configuration. SS group handover and/or PDCCH skipping may be indicated by a Radio Network Temporary Identifier (RNTI). In an example, an interpretation of PS bits may be determined using an RNTI for scrambling a PDCCH Cyclic Redundancy Check (CRC). For example, if the CRC is scrambled with the first RNTI, the WTRU may interpret the PS bits to perform a search space set handover (e.g., SS group handover). For example, if the CRC is scrambled with a second RNTI, the WTRU may interpret the PS bits to apply the skip. One of the RNTUs may be equal to the C-RNTI. In an example, the WTRU may apply the skip operation in a state where PS bits are received. SS group switching and/or PDCCH skipping may be indicated by a BWP type and/or BWP ID. SS group switching and/or PDCCH skipping may be indicated by DCI formats (e.g., 2_2 and 1_1 or 0_1). SS group switching and/or PDCCH skipping may be indicated by the SS receiving the DCI. For example, if the WTRU receives DCI in SS k in SS group M, this bit may be interpreted as a state transition. If the WTRU receives DCI in SS M in SS group M, this bit may be interpreted as a skip request. SS group switching and/or PDCCH skipping may be indicated by the MAC CE. SS group switching and/or PDCCH skipping may be indicated by the WTRU type and/or WTRU category. SS group switching and/or PDCCH skipping may be indicated by DRX parameters and/or DRX types. For example, if short DRX is configured, these bits may be interpreted for SS handover. Skipping may be limited to long DRX only (e.g., long DRX only). The values of the DRX on duration timer and/or the inactivity timer may provide an indication of SS group switch and/or PDCCH skip.

One or more of the following may apply (e.g., trigger) an implicit indication. The reception activity of DCI with a priority indicator may apply an implicit indication. For example, if the WTRU does not receive scheduling DCI with a priority indicator state (e.g., a particular priority indicator state such as priority index=1) in a first state for longer than X slots (or ms), the WTRU may switch to a second state for PDCCH monitoring (e.g., where X may be a time window or a timer). The time window or timer may be reset if the WTRU receives DCI with a priority indicator state (e.g., a particular priority indicator state such as priority index=1) in a slot.

The implicit indication may be applied after a BWP switch. For example, the WTRU may monitor SS group #2 in the first BWP and the WTRU may switch to the second BWP. If the WTRU switches back to the first BWP, the WTRU may monitor SS group #1. The default SS group may be configured, predetermined, and/or used for BWP. The initial SS group for PDCCH monitoring may be the default SS group if the WTRU switches to BWP. The default SS group may be the SS group with the lowest SS group identification, the SS group associated with the first state (e.g., state 0), and/or the SS group configured in BWP. The default SS group may be determined based on the configuration of the search space in the SS group (e.g., each SS group). For example, the SS group including the shortest (or longest) SS monitoring occasion may be determined as the default SS group

Fig. 10A-10C illustrate exemplary handover and PDCCH monitoring skip as described herein

In an example, the code point represented by PS bits may be used by the WTRU to determine an indication (e.g., where the indication may be SS group switch and/or PDCCH skip). In the case of n PS bits, there may be 2 ⁿ Code points. For example, in the case of 2 PS bits, 4 code points may be represented: 00. 01, 10 and 11. These code points may be indicated toThe following. In the case where two code points are used for SS group handover, code point 00 may indicate that if the WTRU is in state 0 (see, e.g., SS group 0 (SSG 0) in fig. 10B and 10C), stay in the current state (see, e.g., 1004 in fig. 10B); and if the WTRU is in state 1 (see, e.g., SS group 1 (SSG 1) in fig. 10B and 10C), then switch to state 0 (see, e.g., 1014 in fig. 10B and 1028 in fig. 10C). Code point 01 may indicate that if the WTRU is in state 1 (see, e.g., SS group 1 (SSG 1) in fig. 10B and 10C), stay in the current state (see, e.g., 1008 in fig. 10B); if the WTRU is in state 0 (see, e.g., SS group 0 (SSG 0) in fig. 10B and 10C), then it switches to state 1 (see, e.g., 1006 in fig. 10B and 1024 in fig. 10C). In the case where two code points are used for PDCCH skipping, code point 10 may indicate to stay in the current state and skip m1 slots (see, e.g., 1002 and 1010 in fig. 10B and 1022 and 1026 in fig. 10C). Code point 11 may indicate to stay in the current state and skip m2 slots (see, e.g., 1016 and 1012 in fig. 10B and 1020 and 1026 in fig. 10C). The number of code points allocated for indicating SS group handover and PDCCH skip may not be equal. One of the code points allocated to PDCCH skipping may indicate skipping until the DRX cycle ends, and/or stop the inactivity timer.

In an example, the code point may indicate to the WTRU to apply SS group switching and PDCCH skipping. For example, code point k means indicating to switch to state L and skip M slots in state L, and/or skip M slots in the current state and then switch to state L.

In an example, a WTRU application bandwidth part (BWP) handover may be indicated in DCI (e.g., the same DCI used to indicate SS group handover). For example, if the WTRU is instructed in DCI (e.g., the same DCI) to apply SS group and BWP handover, the index of the target SS group in the DCI may indicate the SS group monitored in the target BWP. For example, if the target BWP is not configured with an SS group with the indicated index, the WTRU may ignore the signaled index. The target BWP may monitor a default SS group (e.g., a configured SS), a configured SS group, and/or an SS group with a particular index (e.g., an SS group with a lowest or highest index). For example, if the WTRU is instructed to apply BWP handover and perform PDCCH skipping in DCI (e.g., the same DCI), the skip may be applied in the target BWP (e.g., in response to the BWP handover). For example, if the WTRU is instructed in DCI (e.g., the same DCI) to apply BWP handover and perform SS group handover and PDCCH skip, skip may be applied in target BWP, and the index of the target SS group in DCI may determine the SS group monitored in the target BWP.

In an example, the WTRU may be configured with a first set of bits for SS group handover and a second set of bits for PDCCH skipping in the DCI.

For example, one bit (e.g., bit 0) may be configured for SS group switching and two bits (e.g., bits 1 and 2) may be configured for PDCCH skipping. For example, if bit 0 is 0 and the WTRU is in state 0, the WTRU may stay in state 0. For example, if bit 0 is 1 and the WTRU is in state 0, the WTRU may move to state 1. For example, if bit 0 is 1 and the WTRU is in state 1, the WTRU may stay in state 1. For example, if bit 0 is 0 and the WTRU is in state 1, the WTRU may move to state 0.

In an example, bits 1 and 2 may be configured for PDCCH skipping. For example, if bit 1 is 0 and bit 2 is 0, PDCCH skip may not be indicated. For example, if bit 1 is 0 and bit 2 is 1, it may be indicated that M1 slots (e.g., or another time unit, such as Mi monitoring opportunities) are skipped. For example, if bit 1 is 1 and bit 2 is 0, it may be indicated that M2 slots (e.g., or another time unit, such as M2 monitoring opportunities) are skipped. For example, if bit 1 is 1 and bit 2 is 1, skipping may be indicated until the DRX cycle ends.

For example, if the DCI indicates to the WTRU to apply SS group switching and skipping, the order of whether to apply SS group switching first and then skipping (e.g., or vice versa) may be configured and/or predetermined based on rules. For example, the order of bits in the DCI may determine the order of the applied indications. For example, if the index of the SS group switch bit in DCI is smaller than the index of the PDCCH skip bit, SS group switch may be applied before PDCCH skip.

In an example, if DCI is received, the WTRU interprets the code point based on an index of the SS group upon which the PDCCH is monitored (e.g., determines an action indicated by the code point). For example, if PDCCH transmissions are monitored and DCI is received in state 0, the code point may indicate to the WTRU one or more of: 00, which indicates to stay in the current state; 01, which indicates a switch to state 1;10, which indicates to stay in the current state and skip m1 slots; or 11, which indicates to stay in the current state and skip m2 slots.

In an example, if PDCCH transmission is monitored and DCI is received in state 1, the code point may indicate to the WTRU one or more of: 00, which indicates that PDCCH transmission is not skipped; 01 indicating that M1 time slots are skipped (e.g., or another time unit, such as M1 monitoring opportunities); 10, which indicates skipping M2 slots (e.g., or another time unit, such as M2 monitoring opportunities); or 11, which indicates skipping until the end of the DRX cycle.

In an example, the search space group and/or SS may be configured to be "non-switchable from" (e.g., via a parameter SwitchingFromAllowed that may take a value of true or false). If the WTRU is in this state (e.g., not switchable from state), the WTRU may not use explicit L1 signaling to indicate to switch to another state and/or explicit signaling may indicate to the WTRU to perform PDCCH skipping (e.g., PDCCH skipping only). For example, code points (e.g., all code points) may be interpreted as indicating that only skips are performed. The WTRU may switch from this state through another technique than explicit signaling (e.g., expiration of a duration, such as via a timer). In an example, SS group 1 may be configured to be "non-switchable from".

In an example, parameters for the RRC configuration of the SS group and/or SS may be used by the WTRU to determine how to interpret the code point indicated by the DCI bits if DCI is received when the WTRU monitors the PDCCH according to the SS or SS group. For example, one or more of the code points may indicate an SS group switch (e.g., SS group switch only) or PDCCH skip (e.g., PDCCH skip only), or one or more of the code points may indicate an SS group switch and one or more of the code points may indicate PDCCH skip. For example, the parameter may take on the value switchingAllowed, skippingAllowed and/or switchingand skip pin allowed. For example, if the parameter is switchingAllowed, the code point may indicate a handover. For example, if the parameter is skip allowed, the code point may indicate PDCCH skipping. For example, if the parameter is switchingand skip pin allowed, one or more code points may indicate PDCCH skip and one or more code points may indicate SS group handover.

SS group switching and/or PDCCH skipping may be applied to DL retransmissions. In an example, the WTRU may receive DCI with a downlink grant, and the DCI may include an indication to perform PDCCH skipping for the WTRU. The WTRU may apply the indication in a slot (e.g., an n+n_offset slot). For example, n may be a slot index in which a PDCCH transmission is received, and n_offset may be a configurable parameter in the slot and may be a function of WTRU capabilities. The WTRU may apply the indication in the first symbol after the corresponding transmission carrying DL HARQ feedback ends.

In an example, the WTRU may choose not to apply PDCCH skipping for a duration (e.g., duration), e.g., to monitor PDCCH transmissions for possible retransmissions. The WTRU may monitor PDCCH transmissions for duration, e.g., according to the SS set. The SS set may include one or more of the following. The SS set may include a preconfigured SS set (e.g., including a single preconfigured SS). The SS set may include a SS set selected by the WTRU from a group of SSs that the WTRU is monitoring and/or that the WTRU desires to monitor when a DL grant is received. For example, the set may contain one or more SSs from the group with the largest or smallest SS ID. The SS set may be selected from WTRU-specific SSs (e.g., WTRU-specific SS only). The SS set may include SSs upon which downlink grants are received. The SS set may include the SS upon which the initial downlink grant was received (e.g., if the current grant is for retransmission). The SS set may include an SS set selected by the WTRU from among the SS sets for all configurations of BWP. For example, the set may include one or more SSs from the group with the largest or smallest SSID. The SS set may be selected from WTRU-specific SSs (e.g., WTRU-specific SS only). For example, the SS set may include a preconfigured SS set (e.g., including a single preconfigured SS), where the SS set may be monitored for a duration. The WTRU may avoid monitoring the SS set outside of the duration.

In an example, the duration (e.g., the duration that the WTRU may not apply PDCCH skip) may include a corresponding drx-retransmission timer dl timer or a symbol and/or slot in which one of the corresponding drx-retransmission timer dl timer and drx-HARQ-RTT-timer dl timer is running. The corresponding timer may be a timer for a downlink granted HARQ process. For example, if at least one drx-retransmission timer dl timer corresponding to any HARQ process is running, the WTRU may monitor PDCCH transmissions with a reduced SS set. For example, if at least one drx-retransmission timer dl or at least one drx-HARQ-RTT-timer dl corresponding to any HARQ process is running, the WTRU may monitor PDCCH transmissions with a reduced SS set.

In an example, the WTRU may receive DCI with a downlink grant, and the DCI may include an indication for the WTRU to switch to a null state, and the WTRU may start a timer, e.g., null state timer. The WTRU may switch from a null state to a state (e.g., a new state) and/or may stop the null state timer if the data of the corresponding HARQ process is not successfully decoded. For example, the WTRU may stay in a new state if either of the corresponding drx-retransmission timer dl and/or drx-HARQ-RTT-timer dl timers is running, or if the corresponding drx-retransmission timer dl (e.g., only the corresponding drx-retransmission timer dl) is running. For example, if at least one drx-retransmission timer dl timer corresponding to any HARQ process is running, the WTRU may stay in a new state. For example, if at least one drx-retransmission timer dl or at least one drx-HARQ-RTT-timer dl corresponding to any HARQ process is running, the WTRU may stay in a new state. The new state may be a pre-configured state and/or a state in which a DL grant is received.

In an example, the WTRU may ignore the PDCCH skip indication and/or the handover indication to another state (e.g., a null state) and may continue to monitor PDCCH transmissions according to the configured SS, e.g., if one or more of the following conditions are met. One condition is that the data of the corresponding HARQ process is not successfully decoded. For example, if the WTRU sends a NACK for the HARQ process in the first state, the WTRU may not perform PDCCH skip indication nor state switch indication, e.g., unless the WTRU ends the corresponding transmission. For example, in response to the WTRU successfully receiving or sending an ACK for the HARQ process, the WTRU may complete the corresponding transmission. One condition is that the triggered aperiodic CSI report is not reported (e.g., has not yet been reported). For example, the WTRU may be triggered to report aperiodic CSI in time slot n+k1. If the WTRU receives a PDCCH skip or status switch indication before n+k1, the WTRU may perform a PDCCH skip or status switch after n+k1 (e.g., n+k1+1). One condition is that the associated HARQ reporting has not been performed. For example, if the WTRU receives a PDCCH transmission in slot #n, a scheduled Physical Downlink Shared Channel (PDSCH) transmission is received in slot #n+k1 and its associated HARQ report is received in slot #n+k2; the WTRU may not perform PDCCH skipping or status switching, for example, until the WTRU reports HARQ in slot #n+k2. One condition is that the WTRU is in a first mode of operation. For example, if the WTRU is in a first mode of operation (e.g., URLLC), the WTRU may not perform PDCCH skipping or state switching. If the WTRU is in a second mode of operation (e.g., eMBB), the WTRU may perform PDCCH skipping or status switching (e.g., if indicated or triggered). The WTRU may be in a first mode of operation, for example, if the WTRU is configured with at least one of: priority indicator in DCI format; short TTI (e.g., PDSCH or PUSCH scheduling less than slot); or side-link operation.

Fig. 8 is a diagram showing an example of a timeline of DL transmission of a corresponding HARQ process. As shown, for example, each vertical line may represent an OFDM symbol, where the OFDM symbol may be the last symbol of a transmission (e.g., the last symbol of a transmission carrying DL HARQ feedback), as applicable.

In DL transmission, a DRX HARQ timer (such as a DRX-HARQ-RTT-TimerDL) for the HARQ process may be started in the first symbol in response to the end of the corresponding transmission carrying DL HARQ feedback, and a DL retransmission timer (such as a DRX-retransmission TimerDL timer) may be stopped. For example, if the drx-HARQ-RTT-TimerDL timer expires and the data of the corresponding HARQ process is not successfully decoded, a drx-retransmission TimerDL timer of the corresponding HARQ process may be started in the first symbol in response to the drx-HARQ-RTT-TimerDL timer expiring.

In an example, if the WTRU receives an indication (e.g., a skip indication, an indication to switch to a null state, etc.) in the initial grant that the PDCCH transmission is not monitored for a time interval, the WTRU may apply the indication, e.g., if the DL retransmission timer is not running. For example, if the DL retransmission timer is running and the WTRU receives a PDCCH transmission with a DL transmission grant (e.g., a retransmission grant), the WTRU may begin applying an indication in the first symbol in response to the end of the transmission carrying the grant (e.g., in response to the end of the PDCCH transmission with the grant). In an example, the indication may not be applied in the interval from the first symbol at the start of the DL retransmission timer until the last symbol of the transmission carrying the grant. In an example, the indication may not be applied in an interval from the first symbol at the start of the DL retransmission timer until the last symbol of the transmission carrying the grant plus the time offset. The time offset may be configured and may be measured according to the number of OFDM symbols and/or slots. In an example, the indication may not be applied in an interval from the first symbol at the start of the DL retransmission timer until the last symbol before the HARQ feedback transmission ends or until the HARQ feedback transmission ends.

Although the timeline shown in fig. 8 is for a single DL HARQ process, multiple DL HARQ processes may run in parallel. The WTRU may determine applicable intervals for DL HARQ processes (e.g., each DL HARQ process) in which the indication may not be applied, and may not apply the indication in those intervals, for example, if multiple DL HARQ processes are running in parallel.

In an example, the WTRU may not apply the indication, for example, if at least one DL HARQ retransmission timer is running. Not applying this indication may be beyond the scope of not monitoring PDCCH transmissions. As used herein, not applying the indication may include monitoring PDCCH transmissions according to a reduced set of search spaces (e.g., a single preconfigured SS and/or an SS upon which an initial downlink grant is received) as described herein.

SS group switching and/or PDCCH skipping may be applied to UL retransmission. In an example, the WTRU may receive DCI with a downlink grant or an uplink grant, and the DCI may include an indication to the WTRU to perform PDCCH skipping. The WTRU may apply the indication in a slot (e.g., an n+n_offset slot). For example, n may be a slot index in which a PDCCH transmission is received, and n_offset may be a configurable parameter in the slot and may be a function of WTRU capabilities. The WTRU may apply the indication in the first symbol after the end of the first transmission (e.g., within the bundle) of the corresponding PUSCH transmission (e.g., for the uplink grant).

In an example, the WTRU may choose not to apply PDCCH skipping for a duration (e.g., duration), e.g., to monitor the PDCCH for possible retransmissions. The WTRU may monitor PDCCH transmissions for duration, e.g., according to a possibly reduced SS set. The SS set may include a preconfigured SS set (e.g., including a single preconfigured SS). The SS set may include a SS set selected by the WTRU from a group of SSs that the WTRU is monitoring and/or that the WTRU desires to monitor when receiving UL grant. For example, the set may contain one or more SSs from the group with the largest or smallest SSID. The SS set may be selected from WTRU-specific SSs (e.g., WTRU-specific SS only). The SS set may include SSs upon which the uplink grant is received. The SS set may include SSs upon which an initial downlink grant (e.g., new data, non-retransmission) is received. The SS set may include SSs upon which the uplink grant is received. The SS set may include the SS upon which the initial uplink grant is received (e.g., if the current grant is for retransmission). The SS set may include a SS set selected by the WTRU from among the SS sets for all configurations of the BWP. For example, the set may contain one or more SSs from the group with the largest or smallest SSID. The SS set may be selected from WTRU-specific SSs (e.g., WTRU-specific SS only).

In an example, the duration may include a corresponding drx-retransmission timer ul timer or a symbol and slot in which one of the corresponding drx-retransmission timer ul timer and drx-HARQ-RTT-timer ul timer is running. The corresponding timer may be a timer for a downlink granted HARQ process. For example, if at least one drx-retransmission timer ul timer corresponding to any HARQ process is running, the WTRU may monitor PDCCH transmissions with a reduced SS set. For example, if at least one drx-retransmission timer ul timer or at least one drx-HARQ-RTT-timer ul timer corresponding to any HARQ process is running, the WTRU may monitor PDCCH transmissions with a reduced SS set.

In an example, the WTRU may receive DCI with a downlink grant, and the DCI may include an indication for the WTRU to switch to a null state. The WTRU may switch to the null state and the WTRU may start a timer, such as null state timer. The WTRU may switch from a null state to a state (e.g., a new state) and/or may stop the null state timer if the data of the corresponding HARQ process is not successfully decoded. For example, if any corresponding drx-retransmission timer ul and drx-HARQ-RTT-timer ul timers are running, or if the corresponding drx-retransmission timer ul (e.g., only the corresponding drx-retransmission timer ul) is running, the WTRU may stay in the new state. For example, if at least one drx-retransmission timer ul timer corresponding to any HARQ process is running, the WTRU may stay in a new state. For example, if at least one drx-retransmission timer ul or at least one drx-HARQ-RTT-timer ul corresponding to any HARQ process is running, the WTRU may stay in a new state. The new state may be a pre-configured state and/or a state in which UL grant is received.

In an example, if the data of the corresponding HARQ process is not successfully decoded, the WTRU may ignore the PDCCH skip indication and/or switch to a null state indication and may continue to monitor the PDCCH according to the configured SS.

Fig. 9 is a diagram showing an example of a timeline of UL transmission of a corresponding HARQ process. A HARQ uplink timer, such as a drx-HARQ-RTT-timertul timer for a HARQ process, may be started in a first symbol in response to a first transmission end (e.g., within a bundle) for a corresponding PUSCH transmission, and a UL retransmission timer, such as a drx-retransmission timeul timer for a corresponding HARQ process, may be stopped, for example, if a PDCCH transmission indicates a UL transmission. For example, if the drx-HARQ-RTT-timer ul timer expires, a drx-retransmission timer ul timer for the corresponding HARQ process may be started in the first symbol in response to the drx-HARQ-RTT-timer ul expiration.

In an example, if the WTRU receives an indication (e.g., a skip indication, an indication to switch to a null state, etc.) in the initial grant that the PDCCH is not monitored for a time interval, the WTRU may apply the indication, e.g., if the UL retransmission timer is not running. For example, if the UL retransmission timer is running and the WTRU receives a PDCCH transmission with a UL transmission grant (e.g., a retransmission grant), the WTRU may begin applying an indication in the first symbol in response to the end of the transmission carrying the grant (e.g., in response to the end of the PDCCH transmission with the grant).

The indication may not be applied in the interval from the first symbol at the start of the UL retransmission timer until the last symbol of the transmission carrying the grant. In an example, the indication may not be applied in an interval from the first symbol at the start of the UL retransmission timer until the last symbol of the transmission carrying the grant plus the time offset. The time offset may be configured and may be measured according to the number of OFDM symbols and/or slots. In an example, the indication may not be applied in an interval from the first symbol at the start of the UL retransmission timer until the last symbol before PUSCH transmission ends or until the first transmission of PUSCH transmission ends.

Although the timeline shown in fig. 9 is shown for a single UL HARQ process, multiple HARQ processes may run in parallel. The WTRU may determine applicable intervals for UL HARQ processes (e.g., each UL HARQ process) in which the indication is not applied, and may not apply the indication in those intervals.

In an example, the WTRU may not apply the indication, for example, if at least one UL HARQ retransmission timer is running. Not applying this indication may be beyond the scope of not monitoring PDCCH transmissions. Not applying the indication (e.g., as used herein) may include monitoring PDCCH transmissions according to a reduced set of search spaces (e.g., a single pre-configured SS and/or an SS upon which an initial downlink grant is received) as described herein.

SS group switching and/or PDCCH skipping may be applied to Scheduling Request (SR) transmissions. In an example, a WTRU may be in a null state and may send a Scheduling Request (SR). A WTRU monitoring PDCCH transmissions according to a first state may receive an indication to perform PDCCH skipping and/or switch to a null state. If the WTRU transmits a scheduling request with the WTRU performing PDCCH skip and/or being in a null state, the WTRU may perform at least one of the following (e.g., after a time interval, which may be measured from the last symbol of the SR transmission). The WTRU may stop null state timer and/or move to a state (e.g., a new state such as a state in which the WTRU was prior to an empty state, a pre-configured state, or a default state). The WTRU may monitor or resume monitoring PDCCH transmissions based on the first state, the pre-configured state, or a default state (e.g., the default state may be a search space belonging to the SS group with the smallest group ID or a search space belonging to the SS group with ID 0 or one particular search space). For example, the default state may be an SS having a minimum ID associated with SS group 0. For example, if the transmission is an SR, PRACH, or Link Recovery Request (LRR), the techniques described herein may be similarly applicable. The time interval may be a minimum time during which the WTRU does not expect to respond to SR/PRACH/LRR transmissions. The WTRU may monitor or resume monitoring PDCCH transmissions based on the SS set (e.g., where the SS set may be determined based on the SR resource configuration and/or the logical channel that triggered the SR) and/or the priority of the logical channel that triggered the SR and/or the PHY priority of the SR resource. For example, there may be two SS group sets configured to monitor after SR transmission, and the WTRU may select which to monitor based on, for example, logical channel priority and/or SR resource priority. For example, in the case of lower priority SRs and/or lower priority logical channels, the WTRU may monitor PDCCH transmissions from SS groups with smaller IDs (e.g., ID 0). For example, in the case of higher priority SRs and/or higher priority logical channels, the WTRU may monitor PDCCH transmissions according to SS groups with larger IDs (e.g., ID 1). In an example, the WTRU may select an SS (e.g., one SS) from a group of SSs. For example, in the case of lower priority SRs and/or lower priority logical channels, the WTRU may monitor PDCCH transmissions according to the SS having the smallest ID associated with SS group 0. For example, in the case of higher priority SRs and/or higher priority logical channels, the WTRU may monitor PDCCH transmissions according to the SS having the smallest ID associated with SS group 1.

In an example, a WTRU monitoring PDCCH transmissions according to a first state may receive an indication to perform PDCCH skipping in response to switching to a second state (e.g., in response to a skip duration ending). If the WTRU transmits the SR while performing PDCCH skipping, the WTRU may terminate the skipping operation (e.g., the WTRU may monitor or resume monitoring PDCCH transmissions according to the current set of search spaces) and may perform the indicated state switch (e.g., in response to the end of the skip duration). The termination of the skip operation may not change the timing of the state switching. The WTRU may monitor or resume monitoring PDCCH transmissions (e.g., in response to a time interval measured from the last symbol of the SR transmission). In an example, the WTRU may perform the indicated state switch in response to a time interval measured from a last symbol of the SR transmission.

SCell PDCCH monitoring adaptation may be implemented. DCI transmissions received in a primary cell (Pcell) (e.g., via the primary cell) may indicate PDCCH monitoring adaptation in (e.g., for) one or more secondary cells (scells). The adaptation may include Search Space Set Group (SSSG) switching and/or PDCCH skipping. SCell PDCCH monitoring adaptation may use techniques/similar techniques as described herein. In an example, in case of allocating two bits in DCI, each of four code points represented by two bits may indicate SSSG switching and/or PDCCH skipping, or the code points may be reserved.

The DCI (e.g., DCI not used for data scheduling) may be received by the WTRU in the Pcell (e.g., via the Pcell). The DCI may be referred to as non-scheduling DCI. The non-scheduling DCI may include an indication SCellBits of sleep behavior. In an example, one bit may indicate whether dormant BWP or active BWP in the SCell group may be used. In this case, for each configured SCell group, for example, in addition to sleep behavior, the DCI may include one or more additional bits for indicating PDCCH monitoring adaptation. The monitoring adaptation used in the SCell may be a subset of the monitoring adaptation used in the Pcell. The monitoring adaptation indicated in the Pcell may include one or more of the following configured code points. In the case of Pcell, 00 may indicate a switch to SSSG#0, 01 may indicate a switch to SSSG#1, 10 may indicate a skip of m ₁ A time slot, and/or 11 may indicate that m is skipped ₂ And each time slot.

In the case of SCell groups, the indicated monitoring adaptation may be a subset of the configured code points for the Pcell (e.g., 00 may indicate a switch to sssg#0 and 01 may indicate a switch to sssg#1). In this case, the WTRU may not desire to receive other code points (e.g., code points 10 and 11).

PDCCH monitoring adaptation for the SCell may be indicated by one of two bits in the DCI transmission. For example, a Least Significant Bit (LSB) of the bits of 0 may indicate a switch to sssg#0. The LSB of the bits being 1 may indicate a switch to sssg#1.

The number of bits and/or code points used to indicate PDCCH monitoring adaptation may be configured separately for Pcell and Scell. In an example, in the case of scells, one bit may be configured to indicate one or more of: a 0 may indicate a switch to sssg#0, or a 1 may indicate a switch to sssg#1.

Bits allocated to indicate sleep behavior may be used to indicate PDCCH monitoring adaptation. In an example, if the dormant BWP is not configured, a bit configured to indicate the dormant behavior may be used to indicate a switch to one of the two SSSGs in the active BWP. In an example, if a skip is configured and/or indicated (e.g., also configured and/or indicated), one or more of the following may apply. If the WTRU is instructed to switch to an active BWP in the SCell group and SSSG is not configured in BWP, the WTRU may apply a skip (e.g., in addition to one or more common search spaces) to the applicable search spaces (e.g., all applicable search spaces) configured for BWP, e.g., in response to switching to BWP. If the WTRU is instructed to switch to an active BWP in the SCell group and two or more SSSGs are configured in BWP, the WTRU may monitor one of the SSSGs and may apply a skip (e.g., in addition to one or more common search spaces) to the monitored search spaces configured for BWP, e.g., in response to switching to BWP. The SSSG to be monitored may be preconfigured and/or predefined (e.g., the SSSG may be a default SSSG, such as SSSG # 0). The WTRU may apply a skip indication starting from the first symbol when the WTRU starts using active BWP in the SCell. The WTRU may apply a skip indication in the active BWP starting from the first symbol of the first search space monitoring occasion or from the first slot after the last symbol.

The WTRU may ignore the PDCCH monitoring indication bit if the WTRU is instructed to switch to dormant BWP of the SCell group. The WTRU may determine (e.g., from RNTI) that the received non-scheduled DCI transmission includes a bit indicating PDCCH monitoring adaptation. For example, if an indication to switch to active BWP in the SCell group is received, the WTRU may not desire to receive the skip indication.

The skip value and/or timer value configured for SSSG may be configured per BWP in a SCell group, per SCell, and/or per SCell group. In an example, a skip value and/or a timer value configured for BWP may be used if the WTRU is instructed to switch to active BWP in the SCell group and the WTRU is instructed to apply PDCCH monitoring in BWP. If no value is configured for BWP, the WTRU may determine a value to use from the values configured for Pcell. The determined value may be a value configured for PCell, which may be scaled by the subcarrier spacing. In an example, the subcarrier spacing configuration μ=0, 1,2,3 may correspond to subcarrier spacings 15kHz, 30kHz, 60kHz, and 120kHz, respectively. In this case, the value of Scell BWP may be determined byTo determine, where μ0 and μ1 may be subcarrier spacing assignments for BWP in PCell and SCell, respectively And N may be a value configured for BWP in the PCell.

In an example, if scheduling DCI is used, the WTRU may determine PDCCH monitoring adaptation for the SCell group from the adaptation for the PCell indication. The WTRU may apply the same indication to both PCell and SCell. For example, if the indication indicates to switch to an SSSG and if an SSSG with the same index is configured in the SCell, the WTRU may apply the same indication to the SCell. If the DCI transmission indicates to switch to sssg#i in the PCell, the WTRU may switch to sssg#i in the active BWP in the SCell (e.g., if the DCI transmission indicates to switch to the active BWP in the SCell). If SSSG with the same index are not configured in the PCell and SCell, the indication may be ignored by the WTRU. In some cases, the WTRU may not apply the same indication to both the PCell and the SCell. In an example, if the DCI indicates to skip PDCCH monitoring in the PCell, the WTRU may not apply the indication in active BWP in the SCell (e.g., if the DCI indicates to switch to active BWP in the SCell).

The WTRU may be configured to process retransmission and scheduling request processing when the WTRU receives a PDCCH skip request. Based on the received PDCCH scheduling request, the WTRU may not perform PDCCH skipping or may monitor the PDCCH according to a reduced set of search spaces in the time window.

Although the above features and elements are described in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements.

While the implementations described herein may consider 3GPP specific protocols, it should be appreciated that the implementations described herein are not limited to this scenario and may be applicable to other wireless systems. For example, while the solutions described herein consider LTE, LTE-a, new Radio (NR), or 5G specific protocols, it should be understood that the solutions described herein are not limited to this scenario, and are applicable to other wireless systems as well.

The processes described above may be implemented in computer programs, software and/or firmware incorporated in a computer readable medium for execution by a computer and/or processor. Examples of computer readable media include, but are not limited to, electronic signals (transmitted over a wired or wireless connection) and/or computer readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as, but not limited to, internal hard disks and removable disks), magneto-optical media, and optical media (such as Compact Disks (CD) -ROM disks, and/or Digital Versatile Disks (DVD)). A processor associated with the software may be used to implement a radio frequency transceiver for the WTRU, the terminal, the base station, the RNC, and/or any host computer.

Claims

1. A Wireless Transmit Receive Unit (WTRU), the WTRU comprising:

a processor configured to:

receiving a first downlink transmission in a first Search Space (SS) group (SSG), wherein the first downlink transmission includes first configuration information associated with power saving, and wherein the first configuration information is associated with downlink transmission monitoring;

Monitoring a second downlink transmission based on the first configuration information, wherein the processor is further configured to:

in case the first configuration information indicates a first value, monitoring the second downlink transmission in the first SSG,

in case the first configuration information indicates a second value, monitoring the second downlink transmission in a second SSG,

skipping downlink transmission monitoring in the first SSG for a first interval and monitoring the second downlink transmission in the first SSG in response to the first interval ending, if the first configuration information indicates a third value; and

the second downlink transmission is received based on the first configuration information.

2. The WTRU of claim 1, wherein the first downlink transmission is a Physical Downlink Control Channel (PDCCH) transmission, and wherein the first configuration information associated with power saving is indicated in Downlink Control Information (DCI).

3. The WTRU of claim 1, wherein the processor is further configured to receive information associated with power saving, wherein the information indicates the first interval, and wherein the first interval is a time interval, a time slot, an Orthogonal Frequency Division Multiplexing (OFDM) symbol, or a monitoring occasion.

4. The WTRU of claim 3, wherein the received information further indicates a second interval, and wherein monitoring the second downlink transmission based on the first configuration information further comprises the processor being configured to:

in the case that the first configuration information indicates a fourth value, downlink transmission monitoring is skipped in the first SSG for the second interval, and the second downlink transmission is monitored in the first SSG in response to the second interval ending.

5. The WTRU of claim 1, wherein the first SSG comprises a first SS, wherein the first downlink transmission is received in the first SS, and wherein monitoring the second downlink transmission is monitored in the first SS if the first configuration information indicates the first value.

6. The WTRU of claim 1, wherein the first SSG comprises a first SS and the second SSG comprises a second SS, wherein the first downlink transmission is received in the first SS, and wherein monitoring the second downlink transmission is monitored in the second SS if the first configuration information indicates the second value.

7. The WTRU of claim 1, wherein the first SSG comprises a first SS, wherein the first downlink transmission is received in the first SS, and wherein if the first configuration information indicates the third value, the skipped downlink transmission monitoring in the first SSG for the first interval is skipped in the first SS, and monitoring the second downlink transmission in the first SS after the first interval.

8. A method performed by a Wireless Transmit Receive Unit (WTRU), the method comprising:

monitoring a second downlink transmission based on the first configuration information, wherein:

9. The method of claim 8, wherein the first downlink transmission is a Physical Downlink Control Channel (PDCCH) transmission, and wherein the first configuration information associated with power saving is indicated in Downlink Control Information (DCI).

10. The method of claim 8, wherein the method further comprises receiving information associated with power saving, wherein the information indicates the first interval, and wherein the first interval is a time interval, a time slot, an Orthogonal Frequency Division Multiplexing (OFDM) symbol, or a monitoring occasion.

11. The method of claim 10, wherein the received information further indicates a second interval, and wherein monitoring the second downlink transmission based on the first configuration information further comprises:

12. The method of claim 8, wherein the first SSG comprises a first SS, wherein the first downlink transmission is received in the first SS, and wherein monitoring for the second downlink transmission is monitored in the first SS if the first configuration information indicates the first value.

13. The method of claim 8, wherein the first SSG comprises a first SS and the second SSG comprises a second SS, wherein the first downlink transmission is received in the first SS, and wherein monitoring for the second downlink transmission is monitored in the second SS if the first configuration information indicates the second value.

14. The method of claim 8, wherein the first SSG comprises a first SS, wherein the first downlink transmission is received in the first SS, and wherein if the first configuration information indicates the third value, the skipped downlink transmission monitoring in the first SSG within the first interval is skipped in the first SS, and monitoring for the second downlink transmission is monitored in the first SS after the first interval.