WTRU mobility and cell reselection in energy-saving network

Abstract

Systems, methods, and tools for WTRU mobility and cell reselection in an energy saving network are described herein. Handover associated with network energy saving (NES) may be performed. For example, based on a determination that a source cell is entering an NES state and based on a determination that a handover condition is satisfied, a wireless transmit / receive unit (WTRU) may perform a handover from the source cell to a target cell. The WTRU may determine that a handover condition is satisfied, but refrain from performing the handover until it is determined that the source cell is entering the NES state.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 395,183, filed on August 4, 2022, and U.S. Provisional Application No. 63 / 410,081, filed on September 26, 2022, the contents of which are incorporated herein by reference in their entirety. Background Art

[0003] Mobile communications using wireless communications continue to evolve. The fifth generation may be referred to as 5G. Previous (legacy) mobile communications may be, for example, fourth generation (4G) Long Term Evolution (LTE). Summary of the invention

[0004] Systems, methods and tools for WTRU mobility and cell reselection in energy efficient networks are described herein. A handover associated with network energy saving (NES) may be performed. For example, based on determining that a source cell is entering an NES state and based on determining that a handover condition is satisfied, a wireless transmit / receive unit (WTRU) may perform a handover from a source cell to a target cell. The WTRU may determine that the handover condition is satisfied, but refrain from performing the handover until it is determined that the source cell is entering an NES state.

[0005] The WTRU may receive configuration information (e.g., NES-specific configuration information). The configuration information may include a set of handover candidates (e.g., cell candidates). The configuration information may include conditions for NES conditional handover. The WTRU may determine that the source cell is entering an NES state (e.g., a state associated with cell discontinuous transmission, a cell off state, etc.). The WTRU may determine that the source cell is entering an NES state, for example, based on an indication. The indication may indicate that the source cell is entering an NES state, and the indication may indicate a time associated with entering the NES state. The WTRU may determine that the source cell is entering an NES state based on a measurement associated with the source cell. The WTRU may determine that the source cell is entering an NES state based on a determination that a measurement associated with the source cell is less than a threshold. The WTRU may determine that the source cell is entering an NES state based on a determination that a change in a measurement associated with the source cell is greater than a threshold (e.g., a difference between a first measurement and a second measurement of the source cell is greater than a threshold).

[0006] The handover candidates included in the configuration information may include a first handover candidate and a second handover candidate. The first handover candidate may be associated with a first priority and the second handover candidate may be associated with a second priority. The configuration information may indicate that the first handover candidate has priority over the second handover candidate (e.g., the first priority value is associated with a higher priority than the second priority value). The WTRU may determine that both the first handover cell and the second handover cell satisfy the handover condition (e.g., both the first handover cell and the second handover cell are available for selection). For example, based on the first handover candidate being indicated as having priority over the second handover candidate, the WTRU may perform a handover to the first handover cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented;

[0008] Figure 1B is an example of an embodiment in which Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within an illustrated communication system;

[0009] Figure 1C is an example of an embodiment in which Figure 1A A system diagram of an example Radio Access Network (RAN) and an example Core Network (CN) used within the illustrated communication system;

[0010] Figure 1D is an example of an embodiment in which Figure 1A A system diagram of another example RAN and another example CN used within the illustrated communication system;

[0011] Figure 2 An example of the time-frequency structure of SSB is illustrated.

[0012] Figure 3 An example of beam scanning is illustrated.

[0013] Figure 4 An example of configuration and execution of conditional switching is illustrated.

[0014] Figure 5 Examples of NES-specific CHOs and implementations are illustrated.

[0015] Example Network for Specific Implementations

[0016] Figure 1A1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the 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, and filter bank multi-carrier (FBMC), etc.

[0017] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110 and other networks 112, but 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. By way of example, the UE 102a, 102b, 102c, 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to send and / or receive wireless signals and may include a user equipment (WTRU), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0018] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device that is 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 other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, 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.

[0019] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSC), radio network controllers (RNC), relay nodes, etc. Base station 114a and / or base station 114b may be configured to send 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 a licensed spectrum and an unlicensed spectrum. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Therefore, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0020] 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, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0021] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA. For example, the 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 interface 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).

[0022] 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) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[0023] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0024] In an embodiment, 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 together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface used by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0025] 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, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), and GSM EDGE (GERAN).

[0026] Figure 1A The base station 114b in may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in local areas such as commercial venues, homes, vehicles, campuses, industrial facilities, sky corridors (e.g., for use by drones), and roads. In one 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 picocell or a femtocell. As Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not need to access Internet 110 via CN 106 / 115.

[0027] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the text and video, the CN 106 / 115 may be configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Figure 1AAlthough not shown in the figure, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0028] 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. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0029] 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 via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0030] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, 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 peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0031] 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 associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC) and state machine, etc. The processor 118 may perform signal decoding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0032] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from a base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, an IR, UV, or visible light signal. In another embodiment, the send / receive element 122 may be configured to send and / or receive both an RF signal and an optical signal. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0033] Although the transmit / receive element 122 Figure 1B Although depicted as a single element in the figure, 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.

[0034] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0035] 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 (e.g., 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. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, and a secure digital (SD) memory card, among others. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0036] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the 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 cell batteries (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0037] The processor 118 may also be coupled to the 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 the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) 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 will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0038] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, FM radio unit, digital music player, media player, video game player module, Internet browser, virtual reality and / or augmented reality (VR / AR) device and activity tracker, etc. Peripheral device 138 may include one or more sensors, which may be one or more of the following: gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor; geolocation sensor; altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biometric sensor and / or humidity sensor.

[0039] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for both UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via hardware (e.g., a choke) or via signal processing performed by a processor (e.g., a separate processor (not shown) or via the processor 118). In one embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for both UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0040] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0041] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0042] Each of the evolved Node 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, and scheduling of users in the UL and / or DL, among other things. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0043] Figure 1C The illustrated CN 106 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 is depicted as being 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.

[0044] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, and selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0045] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-evolved Node-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0046] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0047] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts 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 networks and / or wireless networks owned and / or operated by other service providers.

[0048] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative embodiments, such terminals may (eg, temporarily or permanently) use a wired communications interface with a communications network.

[0049] In a representative embodiment, the other network 112 may be a WLAN.

[0050] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or out of the BSS. Traffic originating from outside the BSS and destined for the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and destined for a target outside the BSS may be transmitted to the AP to be delivered to the corresponding target. Traffic between STAs within the BSS may be transmitted by the AP, for example, wherein the source STA may transmit traffic to the AP, and the AP may deliver traffic to the target STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source STA and the target STA (e.g., directly between them) using a 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 within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0051] When using the 802.11ac infrastructure operation mode or a similar operation mode, the AP may send beacons on a fixed channel (such as a primary channel). The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by the STA 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, a STA (e.g., each STA) (including the AP) may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0052] High throughput (HT) STAs may communicate using a 40 MHz wide channel (eg, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels) to form a 40 MHz wide channel.

[0053] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and the data can be sent by sending STA. At the receiver of the receiving STA, the above-mentioned operation for 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0054] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support instrument type control / machine type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0055] 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 a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing 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 a STA (supporting only a 1MHz operating mode) is sending to the AP, the entire available band may be considered busy even if most of the band remains idle and may be available.

[0056] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South 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.

[0057] Figure 1D 1 is a system diagram illustrating the RAN 113 and the CN 115 in accordance with an embodiment. As noted above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0058] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0059] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (e.g., containing different numbers of OFDM symbols and / or varying absolute time lengths over time).

[0060] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeB 160a, 160b, 160c may act as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0061] Each of the gNBs 180a, 180b, 180c may be associated with a specific 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 slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b and routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0062] Figure 1DThe illustrated CN 115 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although each of the foregoing elements is 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.

[0063] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different PDU sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing in order to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, and / or services for machine type communication (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0064] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0065] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring, etc.

[0066] 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 acts 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 networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b via the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and the N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0067] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, 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 simulation devices (not shown): WTRU102a-d, base station 114a-b, evolved Node B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b and / or any other device described herein. The simulation device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0068] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all 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. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communications to perform testing.

[0069] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuits (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0070] Systems, methods and tools for WTRU mobility and cell reselection in energy efficient networks are described herein. A handover associated with network energy saving (NES) may be performed. For example, based on determining that a source cell is entering an NES state and based on determining that a handover condition is satisfied, a wireless transmit / receive unit (WTRU) may perform a handover from a source cell to a target cell. The WTRU may determine that the handover condition is satisfied, but refrain from performing the handover until it is determined that the source cell is entering an NES state.

[0071] The WTRU may receive configuration information (e.g., NES-specific configuration information). The configuration information may include a set of handover candidates (e.g., cell candidates). The configuration information may include conditions for NES conditional handover. The WTRU may determine that the source cell is entering an NES state (e.g., a state associated with cell discontinuous transmission, a cell off state, etc.). The WTRU may determine that the source cell is entering an NES state, for example, based on an indication. The indication may indicate that the source cell is entering an NES state, and the indication may indicate a time associated with entering the NES state. The WTRU may determine that the source cell is entering an NES state based on a measurement associated with the source cell. The WTRU may determine that the source cell is entering an NES state based on a determination that a measurement associated with the source cell is less than a threshold. The WTRU may determine that the source cell is entering an NES state based on a determination that a change in a measurement associated with the source cell is greater than a threshold (e.g., a difference between a first measurement and a second measurement of the source cell is greater than a threshold).

[0072] The handover candidates included in the configuration information may include a first handover candidate and a second handover candidate. The first handover candidate may be associated with a first priority and the second handover candidate may be associated with a second priority. The configuration information may indicate that the first handover candidate has priority over the second handover candidate (e.g., the first priority value is associated with a higher priority than the second priority value). The WTRU may determine that both the first handover cell and the second handover cell satisfy the handover condition (e.g., both the first handover cell and the second handover cell are available for selection). For example, based on the first handover candidate being indicated as having priority over the second handover candidate, the WTRU may perform a handover to the first handover cell.

[0073] WTRU mobility and / or carrier reselection may be implemented for a WTRU configured to operate in a network configured for energy efficient operation. Examples of connected mode procedures and behaviors are described for a WTRU operating in a network energy saving (NES) cell, including, for example, mobility, carrier switching, and / or secondary cell (SCell) operation. Examples of idle / inactive mode procedures / behaviors for a WTRU, such as cell reselection, are described.

[0074] In the example of mobility, a group handover for a WTRU may be served by a (e.g., the same) closed cell, bandwidth part (BWP), or gNB. For example, a group common command (e.g., L1, L2, or broadcast signaling) may be used to perform mobility. A conditional handover (CHO) trigger condition may be based on the detection of a change in power saving mode of a neighboring cell and / or a serving cell. A gradual HO / CHO may be based on the duration left by the change in power saving mode of a neighboring cell and / or a serving cell, for example to prevent an overload at the target cell / node (e.g., a random access channel (RACH) overload). For example, if (e.g., when) the WTRU determines that the serving cell and / or the target cell is in power saving mode, an offset may be added to the idle / inactive / connected mode mobility threshold. L1 signaling (e.g., common L1 signaling) may instruct one or more (e.g., a group of) WTRUs to shut down or mute a transmit / receive point (TRP), perform a handover to another TRP, and / or stop monitoring the associated transmit configuration index (TCI) state. An example procedure for performing a random access (RA) to a target cell in a power saving / sleep mode / state is described.

[0075] In the example of cell switching and (re)selection, an example process of SCell operation without synchronization signal block (SSB) transmission / cross-carrier synchronization is described.

[0076] A radio access network (eg, 3GPP RAN) may implement network energy saving (NES). The network may minimize its power consumption for transmission and / or reception. Minimization of power consumption may be beneficial in reducing operating costs and improving environmental sustainability.

[0077] For example, if (e.g., when) there is no data, the network can be (e.g., very) efficient from the perspective of minimizing transmissions from the network. The network can refrain from utilizing (e.g., not utilizing) a cell-specific reference signal (CRS) that is always on. Energy consumption can (e.g., additionally and / or alternatively) be reduced, e.g., as described herein.

[0078] For example, the network may consume energy if (e.g., when) suppressing (e.g., not transmitting) transmissions for other activities such as baseband (e.g., digital) processing for reception or beamforming. In dense networks, such "idle" power consumption may not be negligible, for example, even if no WTRUs are being served during a given period. For example, if the network turns off these activities when no transmissions are being made to the WTRUs, energy consumption may be reduced.

[0079] The network may support beamforming with multiple (e.g., many) ports (e.g., up to 64 transmit and receive ports). Energy consumption may increase with the number of ports utilized. Utilizing a large number of ports may not be necessary for all WTRUs. For example, if the network is able to adjust the number of ports (e.g., only to the number of ports required), energy consumption may be reduced.

[0080] Network energy savings may improve the operation of the cellular ecosystem to enable more efficient adaptation of network transmit and receive resources in the time, frequency, space, and power domains, for example, with support, feedback, and / or other assistance from the WTRU. Echo-friendly WTRU operation may support the deployment of greener network deployments, which allow for reduced emissions and / or reduced operating expense (OPEX) costs for operating cellular networks. Some networks may (e.g., unlike other networks) suppress the use of (e.g., do not require) always-on transmission of synchronization or reference signals, and / or may support adaptable bandwidth and multiple-input multiple-output (MIMO) capabilities. Power savings may be achieved without impacting some WTRUs (e.g., legacy WTRUs). Adaptation of network resources may enable greater efficiency when operating newer deployments and later generations.

[0081] The channel state information (CSI) may include, for example, one or more of the following: a channel quality index (CQI), a rank indicator (RI), a precoding matrix index (PMI), an L1 channel measurement (e.g., a reference signal received power (RSRP), such as L1-RSRP, or a signal-to-interference-plus-noise ratio (SINR)), a channel state information reference signal (CSI-RS) resource indicator (CRI), a synchronization signal (SS) / physical broadcast channel (PBCH) block resource indicator (SSBRI), a layer indicator (LI), and / or any other measurement quantity measured by the WTRU from a configured CSI-RS or SS / PBCH block.

[0082] Uplink control information (UCI) may include, for example, CSI, hybrid automatic repeat request (HARQ) feedback for one or more HARQ processes, scheduling request (SR), link recovery request (LRR), configured grant UCI (CG-UCI) and / or other control information bits that may be sent on a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH).

[0083] Channel conditions may include (e.g., any) conditions related to the state of the radio / channel, which may be determined by the WTRU, for example, based on one or more of: WTRU measurements (e.g., L1 / SINR / RSRP, channel quality indicator (CQI) / modulation and coding scheme (MCS), channel occupancy, received signal strength indicator (RSSI), power headroom, exposure headroom); L3 / mobility-based measurements (e.g., RSRP, reference signal received quality (RSRQ)); radio link monitoring (RLM) status; and / or channel availability in unlicensed spectrum (e.g., whether the channel is occupied based on a determination of a listen-before-talk (LBT) procedure, or whether the channel is deemed to have experienced consistent LBT failures).

[0084] Physical random access channel (PRACH) resources may include one or more of the following: PRACH resources (e.g., in terms of frequency), PRACH timing (RO) (e.g., in terms of time), preamble format (e.g., based on total preamble duration, sequence length, guard time duration and / or based on the length of the cyclic prefix) and / or (e.g., a certain) preamble sequence that can be used to send a preamble in a random access procedure.

[0085] Attributes of the scheduling information (e.g., an uplink grant or a downlink allocation) may include, for example, one or more of the following: frequency allocation; aspects of time allocation, such as duration; priority; modulation and coding scheme; transport block size; number of spatial layers; number of transport blocks to be carried; TCI status or SRI; number of repetitions; and / or an indication of whether the grant is a configured grant type 1, type 2, or a dynamic grant.

[0086] An indication of downlink control information (DCI) and / or another indication may include, for example, one or more of the following: an (e.g., explicit) indication of a radio network identifier (RNTI) via a DCI field or via a cyclic redundancy check (CRC) used to mask a physical downlink control channel (PDCCH); an (e.g., implicit) indication of attributes such as a DCI format, a DCI size, a control resource set (core set) and / or a search space, an aggregation level, an identifier of a first control channel resource used for the DCI (e.g., an index of a first control channel element (CCE)), for example, where the mapping between attributes and values ​​may be signaled by a radio resource control (RRC) or a media access control (MAC); and / or an (e.g., explicit) indication of a downlink (DL) MAC control element (CE).

[0087] The terms network availability state and network energy saving (NES) state may be used interchangeably.

[0088] Network system information (SI) may be provided. The system information (SI) may include, for example, a master information block (MIB) and / or multiple system information blocks (SIBs). The SIB may be divided into a minimum SI and other SIs.

[0089] The minimum SI may carry information that may be used for initial access and / or for acquiring any other SI. The minimum SI may include, for example, MIB and SIB1. A WTRU may acquire the contents of the minimum SI for a cell, for example, in order for the WTRU to (eg, be allowed to) camp on the cell.

[0090] Other SI may include (e.g., all) SIBs that are not broadcast in the minimum SI. The WTRU may receive the SIBs before accessing the cell or may refrain from receiving (e.g., not receiving) the SIBs. Other SI may be referred to as on-demand SI, for example, because a base station (e.g., gNB) may send / broadcast the SIBs upon request (e.g., only when explicitly requested by the WTRU). Sending (e.g., only) upon request may reduce network energy consumption.

[0091] The MIB may include cell barring status information and / or (e.g., basic) physical layer information of cells configured (e.g., required) to receive additional system information (e.g., CORESET#0 configuration information). The MIB may be broadcast (e.g., periodically) on a broadcast channel (BCH). In some examples, the periodicity of the broadcast may be 80 ms. In some examples, repeated transmissions may occur within a broadcast period (e.g., an 80 mS period).

[0092] SIB1 may indicate (e.g., define) the scheduling of other system information blocks (SIBs). SIB1 may include information (e.g., required) for initial access. SIB1 may be referred to as remaining minimum SI (RMSI). SIB1 may be broadcast (e.g., periodically) on a DL shared channel (DL-SCH) and / or may be sent to the WTRU in a dedicated manner, such as on the DL-SCH to a WTRU in RRC_CONNECTED mode.

[0093] A synchronization signal and PBCH block may be provided. A synchronization signal and PBCH block (SSB) may include a primary synchronization signal (PSS) and / or a secondary synchronization signal (SSS). The PSS and / or SSS may (e.g., each) occupy one (1) symbol and / or 127 subcarriers. The PBCH may span three (3) orthogonal frequency division multiplexing (OFDM) symbols and / or 240 subcarriers. For example, Figure 2 As shown in the example in , a symbol can leave unused portions (e.g., in the middle) for SSS.

[0094] Figure 2 An example of a time-frequency structure of an SSB is illustrated. The possible time positions of an SSB within a half-frame may be determined based on the subcarrier spacing and / or the periodicity of the half-frame in which the SSB is transmitted (e.g., configured by the network). Different SSBs (e.g., during a half-frame) may be transmitted in different spatial directions (e.g., using different beams, across the coverage area of ​​a cell).

[0095] Multiple SSBs may be sent within the frequency span of a carrier. The physical layer cell identifier (PCI) of SSBs sent in different frequency locations may or may not be unique. In some examples, different SSBs in the frequency domain may have different PCIs. For example, if (e.g., when) the SSB is associated with a residual minimum SI (RMSI), the SSB may be referred to as a cell-defined SSB (CD-SSB). A primary cell (PCell) may (e.g., always) be associated with a CD-SSB located on a synchronization raster.

[0096] For example, the WTRU may assume a band-specific subcarrier spacing for SSB unless the network has configured the WTRU to assume a different subcarrier spacing.

[0097] One or more (eg, several) beams may be associated with a given cell or SSB. One or more (eg, multiple) SSBs may be transmitted on different beams within a given cell (eg, beam scanning).

[0098] Figure 3 Examples of beam scanning are illustrated. In some examples (e.g., Figure 3), multiple SSBs may be sent (e.g., at certain intervals). (Each) SSB may be identified by a (e.g., unique) number (e.g., SSB index). (Each) SSB may be sent via a specific (e.g., selected) beam radiating in a certain (e.g., selected) direction. Multiple WTRUs may be located at different locations around a base station (e.g., a gNB). The WTRU may measure the signal strength of (e.g., each) SSB detected by the WTRU. The measurement may occur within a specific time period (e.g., the time period of an SSB set). The WTRU may identify (e.g., based on the measurement results) the SSB index with the highest (e.g., strongest) signal strength. As Figure 3 As shown in the example in , beam #1 may be the best beam (eg, the selected beam) for WTRU1, and beam #7 may be the best beam for WTRU2.

[0099] The number of different beams transmitted can be determined by how many SSBs are transmitted within an SSB burst set (e.g., a set of SSBs transmitted within a 5 ms window of SSB transmission). In some examples, the maximum number of SSBs within an SSB set for a first frequency range (FR1) can be 4 or 8, while the maximum number of SSBs within an SSB set for a second frequency range (FR2) can be 64.

[0100] A network availability state and / or NES state may be provided (e.g., indicated, determined, selected, etc.). The WTRU may determine whether to transmit or receive on certain (e.g., one or more) resources, for example, based on the network availability state, which may imply a power saving state of the gNB. The availability state may correspond to a network power saving state or a gNB activity level. The availability state may be uplink and / or downlink specific. The availability state may change from symbol to symbol, slot to slot, frame to frame, and / or at a granularity of longer durations. The availability state may be determined by the WTRU or indicated by the network (NW). The availability state may be, for example, "on", "off", "reduce Tx power", "sleep", "micro sleep", or "deep sleep". The availability state may be abstracted by a NW configuration parameter and / or value. The "off" availability state may indicate (e.g., imply) that the baseband hardware of the gNB is (e.g., completely) turned off. The "sleep" availability state may indicate that the gNB may wake up (e.g., periodically) to send certain (e.g., one or more) signals (e.g., presence signals, synchronization or reference signals) and / or receive certain UL signals. In some examples, one or more availability states may have one or more DL and / or UL resources that are unavailable (e.g., during certain time periods), which may enable the network to shut down baseband processing and / or other activities (e.g., to reduce power consumption). Some measurement resources (e.g., SSB or CSI-RS) may be made available (e.g., only) in one or more (e.g., certain) availability states.

[0101] A WTRU may (e.g., under certain conditions) send a request (e.g., a wake-up request) to the network to modify the availability state to a state where one or more resources are available to the WTRU. The wake-up request may include a transmission that is capable of being decoded by a (e.g., low complexity) receiver at a gNB (e.g., for which the energy consumption requirement is minimal). Here, wake-up request, turn-on request, and turn-on WTRU assistance information may be used interchangeably. In one or more availability states (e.g., a "micro-sleep" or "deep sleep" state), a wake-up request may be (e.g., exclusively) used. A wake-up request may refer to (e.g., implemented by) a physical uplink signal sent by the WTRU to request a change in the availability state. The wake-up request signal may be implemented based on a physical layer configuration. The turn-on request may (e.g., otherwise) be a physical layer indication or L2 indication from the WTRU to the network. The turn-on request indication may be delivered as a MAC CE, UCI, radio resource control (RRC) signaling, PUCCH, or RACH indication. The turn-on request indication may include turn-on WTRU assistance information and / or a positioning report.

[0102] The WTRU may determine the availability state (e.g., NES state) based on (e.g., receiving) an availability state indication (e.g., from L1 / L2 signaling (e.g., L1 / L2 broadcast signaling), such as a group common DCI or indication). The WTRU may determine the availability state (e.g., implicitly) from the receipt of periodic DL signaling (e.g., or the lack of periodic DL signaling). The WTRU may determine whether resources are applicable for transmission / reception and / or measurement of the determined network availability state, for example, based on whether the resources are applicable to the active availability state.

[0103] The availability status may apply to at least one transmit, receive and / or measurement resource. The availability status may apply to at least one time period, such as a time slot and / or a time symbol. The availability status may apply to a serving cell, a cell group, a frequency band, a bandwidth part (BWP), a TRP, a set of spatial elements, and a frequency range within a bandwidth part.

[0104] For example, after receiving DL signaling that changes the availability state of a cell or TRP, the WTRU may determine that the active availability state associated with the cell, carrier, TRP, and / or frequency band will be "off", "deep sleep", or "micro sleep". For example, the WTRU may receive a shutdown command on broadcast signaling (e.g., L1 / L2 broadcast signaling), RRC signaling, DCI (e.g., group common DCI), or DL ​​MAC CE. The WTRU may determine the availability state associated with the cell, carrier, TRP, and / or frequency band, for example, based on receiving an availability state indication (e.g., via L1 / L2 signaling (e.g., L1 / L2 broadcast signaling), such as a group common DCI or indication).

[0105] The WTRU may determine (e.g., implicitly) an availability state (e.g., "off", "deep sleep", "micro sleep", or "dormant") associated with a cell, carrier, TRP, and / or frequency band, for example, based on at least one of the following: receiving a command or signal indicating a change in availability state; receiving a paging message, a paging DCI, a paging PDSCH, and / or a paging-related signal (e.g., a paging early indication (PEI)), which may be based on a subset of paging occasions (POs) (e.g., those aligned with a NES discontinuous reception (DRX) cycle and / or a configured subset of PDCCH resources); a gNB DTX state (e.g., indicating whether the gNB is in active time or whether the associated activity timer is running); lack of detection of a presence indication; time (e.g., time of day); availability state of the associated cell (e.g., another carrier of the same MAC entity, another carrier in the same cell group, another carrier in the same gNB, another sector in the same gNB, and / or a configured associated cell or capacity boosting cell); detection of a PSS (e.g., PSS-only) signal and / or a (e.g., reduced / reduced) SSB signal; detection of an RS signal (e.g., CSI-RS, Positioning Reference Signal (PRS), Tracking Reference Signal (TRS)) or lack of such detection; RRC state of the WTRU (e.g., idle, inactive, or connected mode); whether paging has been received (e.g., within a configured time window); whether system information (e.g., periodic SI or a subset of SIBs) has been received (e.g., within a configured time window); and / or the measured channel condition is below (e.g., or above) a threshold.

[0106] For example, based on receiving a command or signal indicating a change in availability state (such as a group common DCI or signaling (e.g., RRC signaling) or a presence signal in connected mode), the WTRU may (e.g., implicitly) determine the availability state (e.g., "off", "deep sleep", "micro sleep", or "dormant") associated with a cell, carrier, TRP, and / or frequency band. The WTRU may (e.g., implicitly) determine the availability state, for example, based on the receipt of periodic DL signaling. The WTRU may be configured or specified to associate an availability state with one or more DL signal types (e.g., SSB, partial SSB) and / or one or more periodicities.

[0107] For example, based on (received) paging messages, paging DCIs, paging PDSCH transmissions, or paging related signals (e.g., PEIs), which may be based on a subset of POs (e.g., those aligned with the NESDRX cycle or a configured subset of the PDCCH), the WTRU may (e.g., implicitly) determine an availability state (e.g., "off", "deep sleep", "micro sleep", or "dormant") associated with a cell, carrier, TRP, and / or frequency band. The WTRU may determine (e.g., assume) an availability state, for example, based on (e.g., after receiving the paging message) a paging RNTI (P-RNTI) (e.g., a specific), a NES P-RNTI (e.g., a separately configured) and / or a NES group RNTI. The WTRU may determine (e.g., assume) a specific availability state, for example, based on the P-RNTI (e.g., after receiving a paging message with a specific P-RNTI). The WTRU may be configured with one or more PEI subgroups for the NES. A subgroup may be associated with one or more availability states. For example, if a subgroup is configured and / or associated with an availability state, the WTRU may determine (e.g., assume) a certain availability state based on (e.g., upon receiving) a PEI with an NES subgroup. An indication of an availability state and / or an availability state switch may be indicated in a paging payload as, for example, a flag portion of a paging message and / or a short message. When the cell from which the signaling is received is off, asleep, or in an NES state, the paging indication may be associated with (e.g., further) indicating (e.g., replacing) a cell monitoring paging. The paging indication may (e.g., further) indicate or signal (e.g., applicable) reconfiguration parameters (e.g., for initial access, applicable PRACH resources, applicable SSB / RS timing, applicable SI cycle and / or applicable cell and / or associated availability state).

[0108] The WTRU may determine (e.g., implicitly) an availability state (e.g., "off", "deep sleep", "micro sleep", or "dormant") associated with a cell, carrier, TRP, and / or frequency band, for example, based on a lack of detection of a presence indication (e.g., determining that no presence indication was received). For example, if no presence indication is detected at one or more presence indication occasions, the WTRU may determine an availability state (e.g., "off" or "deep sleep") associated with a cell. For example, the WTRU may determine (e.g., assume) or change the availability state of a cell based on a false detection (e.g., after a plurality of consecutive false detections) and / or after a duration of time has elapsed (e.g., a timer has expired), for example, without detecting a presence signal. In some examples, after a timer associated with the availability state has expired, the WTRU may determine that the availability state is active or deactivated. The WTRU may determine (e.g., implicitly) an availability state, for example, based on a lack of reception of (e.g., periodic) DL signaling. For example, the WTRU may receive configuration information indicating (e.g., configured with) a signal quality threshold (e.g., an RSRP threshold). For example, if the WTRU does not detect a signal associated with an availability state (e.g., a signal present or SSB) having a signal strength (e.g., at or) above a signal quality threshold, the WTRU may determine that the availability state is not active and / or may determine a different availability state. The criteria / condition may (e.g., also) be combined with a lack of detection of an identification sequence for a signal present (e.g., detection of a PSS sequence).

[0109] The WTRU may determine (e.g., implicitly) an availability state (e.g., "off", "deep sleep", "micro sleep", or "dormant") associated with a cell, carrier, TRP, and / or frequency band, for example, based on time (e.g., time of day). For example, the WTRU may be configured to determine (e.g., automatically assume) a certain availability state (e.g., off, sleep, or dormant) for a configured subset of cells (e.g., capacity boosting cells) based on time (e.g., time of day). In some examples, the WTRU may determine that a capacity boosting cell has an availability state of "on" at a first configured time (e.g., hour of day), an availability state of "deep sleep" at a second configured time (e.g., hour of day), and / or an availability state of "off" at a third configured time (e.g., hour of day).

[0110] A WTRU may receive configuration information indicating (e.g., configured to) monitor for an indication that may characterize a level of network activity (e.g., availability status). Network activity may be associated with a gNB and / or cell. The WTRU may determine (e.g., assume) that the same availability status is assumed for multiple (e.g., all) cells that are part of the same gNB (e.g., cells of the same MAC entity). A network activity indication (e.g., presence indication) may include a channel (e.g., PDCCH) and / or a signal (e.g., sequence). The activity indication may indicate an activity level that the WTRU may expect from the associated gNB and / or cell, e.g., reduced activity. The activity indication may include activity information of other gNBs / cells. The activity indication may be a PDCCH with group common signaling. For example, the NW may send a group common DCI to a group of WTRUs (e.g., WTRUs in a serving cell) to indicate a change in activity status or activity level in the UL and / or DL. The CRC of the PDCCH may be scrambled with a dedicated "activity indication RNTI". The WTRU may receive configuration information indicating (e.g., configured with) a (e.g., at least one) search space associated with a monitoring opportunity for an activity indication PDCCH. The indication may include, for example, an entry sleep signal, such as a (pre-)defined / (pre-)configured sequence. For example, if (e.g., when) the WTRU detects a sequence, the WTRU may expect a reduced activity level (e.g., for a specific / configured duration). The WTRU may activate connected mode DRX (C-DRX) for the indicated / configured time period. In some examples, multiple (e.g., two) sequences may be used to indicate normal activity and reduced activity.

[0111] The signaling or activity indication within the PDCCH may include, for example, at least one of: an expected activity level (e.g., availability status) of the associated gNBs / cells within a time interval; transmission and / or reception properties for (e.g., each) activity level (e.g., availability status); one or more (e.g., a set of) configurations that may be used / applicable for the associated / indicated activity level; a time interval over which the activity level is assumed (e.g., as may be signaled in a PDCCH or part of the activity indication); and / or a (pre-)determined / (pre-)configured time interval over which the activity level is determined (e.g., assumed).

[0112] Signaling and / or activity indications within the PDCCH may include the expected activity level (e.g., availability status) of the associated gNBs / cells within a time interval. The activity level may be predetermined and / or configured. The activity level may include normal and reduced activity. Signaling may indicate the activity level. For example, a bit "1" may indicate normal activity, while a bit "0" may indicate reduced activity.

[0113] Signaling and / or activity indications within the PDCCH may include transmission and reception properties for (e.g., each) activity level (e.g., availability state). For example, the WTRU may not (e.g., be expected to) monitor a particular PDCCH search space (e.g., including all SSs), receive a particular type of PDSCH (e.g., including all PDSCHs), transmit PUCCH / PUSCH, and / or perform certain measurements (e.g., during reduced activity).

[0114] The signaling and / or activity indication within the PDCCH may include configuration information associated with an activity level (e.g., one or more (e.g., a set thereof) configurations), which may be used / applied if (e.g., when) the activity level is indicated. The configuration information associated with the activity level may indicate, for example, an SS configuration, a CSI report configuration, an index of a transmitted SSB, etc. The set (e.g., each) of the configurations may have attributes associated with the activity level. The attributes associated with the activity level may include, for example, a label that may be set to "reduced activity".

[0115] Signaling and / or activity indications within the PDCCH may include time intervals over which activity levels are determined / assumed. For example, a bitmap may be used to indicate time intervals. (Eg, each) bit in the bitmap may be associated with a specific duration (e.g., a time slot or frame). For example, a bit "1" may indicate regular activity, while a bit "0" may indicate reduced activity on an associated frame. Time intervals may be indicated using a start time and / or an interval length. The start time may be determined; for example, by adding a (e.g., fixed) offset to the time at which the indication is received. The length of the interval may be configured or signaled in the indication PDCCH transmission.

[0116] In the event that the current serving cell or capacity boosting cell is turned off and / or a certain (e.g., configured, indicated, specific) condition is met, the WTRU may receive configuration information indicating (e.g., configured or predefined with) (e.g., alternative) serving cell to perform initial access, mobility, or cell reselection. The WTRU may be configured (e.g., per broadcast signaling or dedicated signaling) with a list of fallback or alternative serving cells (e.g., per serving cell or per gNB). For example, the WTRU may initiate a cell reselection or mobility procedure to an alternative serving cell associated with the cell and / or gNB from which the turn-off indication was received. In some examples, the turn-off or going to sleep indication may indicate to the WTRU (e.g., dynamically) which cell to fall back to or connect to. For example, the indication may be provided via dedicated or broadcast signaling. The fallback / alternative cell may be (pre)configured or (pre)defined as a cell within the same gNB from which the sector has entered the NES state (e.g., off, sleep, or reduced power). For example, if the WTRU is in dual connectivity, the fallback cell may be (pre)configured / (pre)defined as a primary node cell. The fallback / alternative cell may be (pre-)configured or (pre-)defined as a cell associated with a different RAT or frequency band. For example, the WTRU may fall back to an LTE or FR1 cell associated with the cell or gNB from which the shutdown indication was received (e.g., if the WTRU is in carrier aggregation (CA) or dual connectivity (DC) using multiple RATs or multiple frequency bands).

[0117] For example, if applicable in an active availability state, the WTRU may determine that uplink or downlink resources and / or signals are applicable for transmission / reception and / or measurement for the determined network availability state. The WTRU may determine that one or more (e.g., a subset thereof) measurement resources and / or signals (e.g., SSB, CSI-RS, TRS, PRS) are not applicable in one or more (e.g., certain) availability states. The WTRU may determine that one or more (e.g., a subset thereof) uplink or downlink resources (e.g., PRACH, PUSCH, PUCCH) are not applicable in certain availability states. The WTRU may, for example, (only) send one or more (e.g., some) uplink signals in a subset of NW availability states (e.g., sounding reference signal (SRS), positioning reference signal (pRS) (e.g., positioning sounding reference signal (pSRS)), PRACH, UCI).

[0118] NES WTRU groups may be provided. WTRUs may be grouped for NES purposes, e.g., to control multiple WTRUs (e.g., simultaneously), e.g., to indicate a BWP switch, to indicate a change in NW availability state, to indicate a change in WTRU DRX cycle / parameters, for activation / deactivation of mobility / cell reselection, paging and / or DL ​​measurement resources. The WTRU may be configured with a NES group RNTI (e.g., NES group identifier) ​​that may be used to signal one or more WTRUs in a (e.g., the same) serving cell. The WTRU may monitor cell-specific DL resources to receive control and / or data, and / or receive group common indications for the NES (e.g., group common DCI, availability state switch command, or NES PCell switch command).

[0119] A cell presence indication may be provided. The WTRU may monitor for receipt of a presence indication or signal associated with a gNB configured with one or more availability states (e.g., on, off, dormant, and / or deep sleep). The presence indication may be a physical downlink signal sent by an associated cell or gNB that is sleeping (e.g., in certain availability states such as deep sleep, micro-sleep, dormant, or off). The presence indication may (e.g., alternatively) be downlink information (e.g., downlink information bits) delivered to the WTRU, for example, via broadcast signaling (e.g., system information block (SIB)) or via dedicated signaling (e.g., RRC signaling or MAC CE).

[0120] The WTRU may change to an availability state based on / associated with (e.g., detected) the presence of a signal (e.g., the WTRU assumes "ON"). For example, the WTRU may receive a response (e.g., successfully) from the requested cell. The response may be provided to the sent WTRU assistance information or the connection request. The response may be the reception of a DL signal or channel (e.g., SSB, CSI-RS, PRS, PDCCH, DCI, PDSCH, HARQ-ACK) or an L2 message (e.g., RRC message, DL MAC CE, Msg2, MsgB, or Msg4). The WTRU may monitor (e.g., start monitoring) additional TRP, SSB and / or CSI-RS resources, for example, after the transmission of wake-up WTRU assistance information or the successful reception of the connection request or response. For example, after the WTRU (e.g., successfully) measures the channel conditions (e.g., RSRP, SINR) above the configured threshold on the measurement resources of the associated cell, the WTRU may change to an availability state associated with the detection of the presence of a signal (e.g., ON).

[0121] For example, the presence indication signal may be at least one of: a simplified or clipped SSB signal, e.g., PSS / SSS without PBCH multiplexing, wide beam or omnidirectional SSB, PRS, CSI-RS, a signal detected based on energy sensing (e.g., a DL signal associated with a wake-up radio, e.g., if the WTRU is equipped with the capability to detect DL signals), a PDSCH or PDCCH received on a different cell or TRP (e.g., on a configured subset of resources), core set, or search space, and / or one or more SSBs received on a different cell or TRP (e.g., configured on a subset of SSB opportunities).

[0122] Conditional Handover (HO) and Conditional Primary Assisted (PSCell) Change (CPC) in the network may be provided. Conditional Handover (CHO) and Conditional PSCell Addition (CPA) / Conditional PSCell Change (CPC) may reduce the likelihood of Radio Link Failure (RLF) and / or Handover Failure (HOF). CPA / CPC may be collectively referred to as CPAC.

[0123] A handover (e.g., a legacy LTE / NR handover) may be triggered by a measurement report. The network may send a HO command to the WTRU without receiving a measurement report. For example, if (e.g., when) the radio signal level / quality (e.g., RSRP, RSRQ, etc.) of a neighboring cell becomes better than the primary serving cell (PCell) or the primary secondary serving cell (PSCell), the WTRU may be configured with an A3 event that triggers a measurement report to be sent, such as in the case of dual connectivity (DC). The WTRU may monitor the serving cell and the neighboring cells. For example, if (e.g., when) a condition is met, the WTRU may send a measurement report. The network (e.g., the current serving node / cell) may (e.g., if (e.g., when) a report is received) prepare a HO command (e.g., an RRC reconfiguration message, such as with reconfigurationWithSync). The network may transmit the HO command to the WTRU. The WTRU may (e.g., immediately) execute the HO command, which may result in the WTRU connecting to the target cell.

[0124] CHO may be different from other handovers (e.g., legacy handovers). For example, multiple handover targets may be prepared for CHO (e.g., compared to one target for another type of handover). The WTRU may refrain (e.g., immediately) from performing CHO (e.g., compared to immediate performance of another type of handover), for example, until a CHO condition is satisfied (e.g., the WTRU may evaluate the CHO condition but refrain from performing CHO until a trigger (e.g., the source cell is entering the NES state) is received / satisfied, such as Figure 5The WTRU may receive (e.g., be configured with) configuration information having trigger conditions (e.g., NES-specific switching conditions) for CHO, such as, for example, a set of radio conditions. For example, if (e.g., when) the trigger conditions are met, the WTRU may perform a conditional handover toward one of the targets.

[0125] For example, a CHO command may be sent if (e.g., when) radio conditions toward the current serving cell are still good, thereby reducing the likelihood of failures in handover, such as: failure to send a measurement report, such as if (e.g., when) the link quality to the current serving cell drops below a threshold (e.g., an acceptable level), if (e.g., when) a measurement report is triggered for handover; and / or failure to receive a handover command, such as if (e.g., when) the link quality to the current serving cell drops below a threshold (e.g., an acceptable level) after the WTRU sends a measurement report but before the WTRU receives a HO command.

[0126] The triggering conditions for CHO may (e.g., additionally and / or alternatively) be based on the radio quality of the serving cell and / or neighboring cells (e.g., conditions that may be used to trigger measurement reports). For example, the WTRU may be configured with CHO with triggering conditions similar to A3 and associated HO commands. The WTRU may monitor the current cell and / or the serving cell. For example, if (e.g., when) the A3 triggering conditions are met, the WTRU may execute the associated HO command and switch the connection to the target cell (e.g., instead of sending a measurement report).

[0127] Figure 4 An example of configuration and execution of conditional switching is illustrated.

[0128] Figure 5 Examples of NES-specific CHOs and implementations are illustrated.

[0129] CHO may help prevent unnecessary reestablishment in the event of a radio link failure (RLF). For example, the WTRU may receive a configuration indication indicating (e.g., configured with) multiple CHO targets (e.g., handover candidates). The WTRU may experience an RLF before a trigger condition with any of the targets is met. In some examples (e.g., legacy operation), an RRC reestablishment procedure may be implemented, which may incur a significant interruption time for the bearers used for the WTRU. In some examples, the WTRU may terminate a cell with which the WTRU has an associated CHO (e.g., a target cell being prepared for handover), for example, after detecting an RLF. For example, the WTRU may execute a HO command associated with the target cell instead of continuing with a full reestablishment procedure.

[0130] CPC and CPA are extensions of CHO, for example in DC scenarios. The WTRU may receive configuration information indicating (e.g., configured with) a trigger condition for a PSCell change or addition. For example, if (e.g., when) the trigger condition is met, the WTRU may execute the associated PSCell change or PSCell add command.

[0131] Measurement and event configuration information for handover and conditional handover may be provided. The measurement configuration information provided to the WTRU may include, for example, one or more of the following: one or more measurement objects; one or more reporting configurations; one or more measurement ID configurations; S-measurement configuration; quantity configuration; and / or measurement gap configuration.

[0132] The measurement object may specify what the WTRU may measure and / or information about how the measurement may be performed. The information may include, for example, one or more of the following: RAT, frequency, subcarrier spacing, SSB periodicity / offset / duration, reference signal and / or signal type to be measured, a list of allowed / excluded neighbor cells of the RAT / frequency of interest to be measured, measurement gaps, offsets that may be applied to prioritize / de-prioritize certain cells, etc.

[0133] A WTRU may receive configuration information indicating (e.g., be configured with) a plurality of measurement objects. A WTRU may have measurement configurations associated with different frequencies and / or different RATs. A WTRU may receive (e.g., be configured with) configuration information for (e.g., up to 64) measurement objects. (e.g., each) measurement object may be identified by a measurement object ID.

[0134] The reporting configuration information may specify (e.g., indicate) what to report (e.g., reference signal type (such as CSI-RS or SSB), beam and / or cell level quantities (such as RSRP / RSRQ) to report, maximum number of cells and / or beams to report, etc.). The reporting configuration information may specify reporting criteria. For example, if (e.g., when) the criteria are met, the WTRU may send a measurement report or perform an associated HO configuration (e.g., in the case of CHO). The reporting criteria may be, for example, the expiration of a periodic timer (e.g., a periodic reporting configuration) and / or based on one or more radio conditions of the serving cell and / or neighboring cells. The WTRU may be configured with (e.g., up to 64) reporting configurations. (Each) reporting configuration may be identified by a reporting configuration ID.

[0135] A measurement object may be associated with one or more reporting configurations. The association may be performed via a measurement ID. For example, a measurement ID configuration may be a list of one or more of: a measurement ID; a measurement object ID; and / or a reporting configuration ID.

[0136] The WTRU may be configured with (e.g., up to 64) measurement IDs. Event-triggered reporting may be configured, for example, based on one or more of the following events: Event A1 (e.g., the serving cell (e.g., measurement) becomes greater than (e.g., better than) a threshold); Event A2 (e.g., the serving cell (e.g., measurement) becomes less than (e.g., worse than) a threshold); Event A3 (e.g., the neighboring cell (e.g., measurement) becomes a larger (e.g., better) offset than the SpCell (e.g., source cell measurement); Event A4 (e.g., the neighboring cell (e.g., measurement) becomes greater than (e.g., better than) a threshold); Event A5 (e.g., the SpCell (e.g., source cell measurement) becomes less than (e.g., worse than) a first threshold (e.g., source cell measurement); , threshold 1) and the neighbor cell (e.g., measurement) becomes greater than (e.g., better than) a second threshold (e.g., threshold 2)); event A6 (e.g., the neighbor cell (e.g., neighbor cell measurement) becomes a larger (e.g., better) offset than the SCell (e.g., source cell measurement); event B1 (e.g., the inter-RAT neighbor cell (e.g., measurement) becomes greater than (e.g., better than) a threshold); and / or event B2 (e.g., the PCell (e.g., source cell measurement) becomes less than (e.g., worse than) a first threshold (e.g., threshold 1) and the inter-RAT neighbor cell (e.g., measurement) becomes greater than (e.g., better than) a second threshold (e.g., threshold 2)).

[0137] The term SpCell refers to a primary cell (PCell) or a primary secondary cell (PSCell) (e.g., in the case of DC). Events A3, A5, B2 can be configured (e.g., only) for PCell or PSCell. Events A1, A2, A3, A5, B2 can be configured for any serving cell. Event A6 can be configured (e.g., only) for SCell (e.g., for secondary cells in carrier aggregation (CA)). Events A4 and B1 can be related to neighbor cell measurements (e.g., not related to any serving cell).

[0138] (Eg, each) event configuration may be associated with a threshold (e.g., offset), hysteresis, and / or time to trigger (TTT) parameters.

[0139] In the case of CHO (e.g., instead of sending a measurement report), for example, if (e.g., when) the reporting conditions are met, the WTRU may perform HO (e.g., execute a HO command). For example, CHO may be implemented based on one or more of the following event-triggered reporting configurations: CondEvent A3 (e.g., the neighbor cell (e.g., measurement) becomes a larger (e.g., better) offset than the source cell (e.g., SpCell measurement)); CondEvent A4 (e.g., the neighbor cell (e.g., measurement result) becomes greater than (e.g., better than) a threshold); and / or CondEvent A5 (e.g., SpCell (e.g., source cell measurement) becomes less than (e.g., worse than) a first threshold (e.g., Threshold 1) and the neighbor cell (e.g., measurement) becomes greater than (e.g., better than) a second threshold (e.g., Threshold 2)).

[0140] The CHO configuration information may include, for example, one or more of: a conditional reconfiguration ID; a conditional reconfiguration trigger condition; and / or an RRC reconfiguration, which may be performed if (eg, when) a condition (eg, HO command) is met.

[0141] The trigger condition may refer to one or more (e.g., two) measurement IDs. Multiple (e.g., two) measurement IDs may be specified. Multiple measurement IDs may refer to the same measurement object (e.g., one measID that associates a measurement object related to the PCell with an A3 event and another measID that associates the same measurement object with an A5 event).

[0142] In some examples, the WTRU may receive configuration information indicating (eg, be configured with) a maximum number (eg, eight (8)) of CHO configurations.

[0143] Network energy consumption may be significant and in some cases unnecessary, such as during quiet hours. For example, the network may (e.g., determine) to shut down small cells and rely on macro cells for coverage during quiet hours, shut down one or more (e.g., some) sectors or gNBs, reduce power amplifier (PA) power consumption, and / or enable gNB-side sleep mode, for example, without significantly / considerably sacrificing WTRU performance. In some examples, the gNB may combine information such as WTRU measurements, WTRU assistance information, interference status, load information, proprietary information, and / or the like to make a determination / decision regarding energy conservation.

[0144] For example, if (e.g., when) one or more (e.g., some) cells activate NES and the WTRU (e.g., in IDLE or INACTIVE state) is unaware that the gNB is in NES state (e.g., deep sleep or sleep), the WTRU may experience coverage loss. The network available resources may be adapted to help the WTRU distinguish whether common cell signals (e.g., SSB, paging, SI) are transmitted (e.g., as usual) or whether the cell signal is not received due to poor channel conditions.

[0145] For example, if (e.g., when) the gNB is asleep or turned off, one or more WTRU control plane processes used for connectivity management, WTRU reachability, cell reselection and / or WTRU battery consumption may be affected, including one or more of the following issues: inter-cell mobility and / or intra-cell mobility / TRP muting.

[0146] In the example of inter-cell mobility, if (e.g., when) the gNB is shut down or enters a dormant or deep sleep state, the network may determine to offload / handover the remaining connected WTRUs to other cells in the area. Executing the handover command / RRC reconfiguration for (e.g., each of the) remaining WTRUs may involve signaling, which may delay the time when the gNB enters sleep. The gNB may use conditional handover (CHO) to reduce the HO signaling load. For example, if (e.g., when) a CHO condition is met (e.g., the signal level of the serving cell / neighboring cell meets an absolute threshold / relative threshold), the WTRU may trigger mobility by configuring one or more candidate cells for handover. Reliance on conditions (such as RSRP) for conditional handover may affect the load distribution, such as if (e.g., when) a large number of WTRUs suddenly migrate to the same cell, which may create a RACH storm. Mobility to other gNBs may (e.g., also) involve re-acquisition of security keys.

[0147] The WTRU may not (eg, yet) be aware of which SSB / RACH opportunities are used for RAs initiated at the target cell.Sending a preamble to a sleeping target cell may prolong the handover process or may cause the handover process to fail prematurely (eg, due to expiration of the T304 timer).

[0148] For example, configuring CHO for multiple WTRUs may consume significant resources at the network unless CHO is performed within a short period of time.

[0149] In the example of intra-cell mobility / TRP muting, if (e.g., when) a TRP is muted, TRP on / off may be enabled for cells with multiple TRPs. The remaining connected WTRUs served by the TRP may stop monitoring the PDCCH with associated TCI state and CSI-RS associated with the TRP, for example, to avoid beam failure detection for the TRP despite no transmitted beam.

[0150] The terms “energy saving mode”, “power saving mode” and “sleep mode” may be used interchangeably.

[0151] Measurement reporting, cell reselection, and mobility may be provided in NES. A WTRU may obtain / receive information (eg, indication) regarding current or upcoming changes in the NES state of a serving cell and / or neighboring cells (eg, an indication that a source cell is entering a NES state).

[0152] In some examples, the WTRU may perform detection of a transition of a serving cell to a power saving mode (e.g., NES state, such as when the serving cell is turned off) by reading system information broadcast on the serving cell. System information (SI) may include timing information (e.g., relative time information or absolute time information) that may indicate when the serving cell will be turned off and / or begin operating in a power saving mode (e.g., the information may indicate the time when the source cell is entering (e.g., will enter) the NES state).

[0153] In some examples, the WTRU may perform detection of a neighbor cell transition to a power saving mode (e.g., NES state, such as a serving cell being turned off) by reading system information broadcast on the neighbor cell. The system information may include timing information (e.g., relative time information or absolute time information) that may indicate when the neighbor cell will be turned off and / or begin operating in a power saving mode.

[0154] In some examples, the WTRU may perform detection of a neighbor cell transition to a power saving mode (e.g., NES state, such as a serving cell being turned off) by reading system information broadcast on the serving cell. The system information may include timing information (e.g., relative time information or absolute time information) that may indicate when the neighbor cell will be turned off and / or begin operating in a power saving mode.

[0155] In some examples, the WTRU may be provided with dedicated information (e.g., in an RRC message, MAC CE, etc.). The information may indicate when the serving cell and / or neighboring cells will transition to a power saving mode, availability state, and / or will be turned off. For example, the information may indicate an absolute time, a relative delta time from when the information was received, etc.

[0156] In some examples, the WTRU may be provided with shared information / group information (e.g., in a DCI scrambled with a WTRU group identity). The information may indicate when the serving cell and / or neighboring cells will transition to a power save mode, availability state, and / or will be turned off. For example, the information may indicate an absolute time, a relative delta time since the information was received, etc. Different DCIs may be specified for different NES states.

[0157] The measurement report may be triggered by a current or upcoming change in the NES state of the serving cell and / or the neighboring cell. In some examples, the WTRU may be configured to send a measurement report to the network based on (e.g., based on) detecting that the NES state of the serving cell and / or the neighboring cell has changed or is expected to change (e.g., transitioned to a power saving mode, turned off, transitioned to a non-power saving mode, etc.).

[0158] The WTRU may perform conditional / group handover, for example, based on information about current or upcoming changes in the NES status of the serving cell and / or neighbor cells.

[0159] In some examples, the WTRU may perform a (pre-)configured HO (e.g., CHO) toward a target cell based on (e.g., based on) detecting that a current serving cell is being turned off or transitioning to a power saving mode (e.g., a different availability state, such as an NES state). For example, the detection may include receiving an availability state switch command (e.g., an indication) and / or determining that the cell is in a given availability state (e.g., determining that the cell is entering the NES state). Performing a HO based on a condition (e.g., detection or determination) may be considered a CHO with a trigger condition based on the power saving mode or availability state of the current serving cell (e.g., the WTRU may refrain from performing a CHO (e.g., if the trigger condition is met) until it is determined that the cell (e.g., the source cell) is entering the NES state).

[0160] In some examples, the WTRU may perform a pre-configured HO upon detecting that a neighboring cell is being turned on or transitioning to a fully operational state (e.g., from a power saving mode or a different availability state). Performing a HO based on a condition (e.g., detection or determination) may be considered a CHO utilizing a trigger condition based on the power saving mode or availability state of the target cell.

[0161] In some examples, CHO that considers the energy-saving state of the serving cell and / or neighboring cells may (eg, further) be constrained by the signal level of the current serving cell and / or target cell. For example, the WTRU may be configured with one or more of the following triggers for CHO: (a) RSRP_target>RSRP_serving+threshold1, for example, if (e.g., when) both cells are in normal operation mode; (b) RSRP_target>RSRP_serving+threshold2, for example, if (e.g., when) the serving cell is in power saving mode and the target is in normal operation mode; (c) RSRP_target>RSRP_serving+threshold3, for example, if (e.g., when) the serving cell is in normal mode and the target is in power saving mode; (d) RSRP_target>RSRP_serving+threshold4, for example, if (e.g., when) both cells are in power saving mode; (e) RSRP_target>threshold_5, for example, if (e.g., when) the serving cell is no longer detected (suddenly turned off) and the target is in normal mode; and / or (f) RSRP_target>threshold_6, for example, if (e.g., when) the serving cell is no longer detected (suddenly turned off) and the target is in power saving mode.

[0162] In some examples (eg, trigger (b)), Threshold_2 may be negative (eg, the WTRU may be offloaded to the target even if the radio conditions to the source are better).

[0163] In some examples, Threshold_3 may be greater than Threshold_1, for example, to ensure that the WTRU is switched to a power saving target cell (eg, only) if conditions in the target cell are much better than conditions in the source cell.

[0164] In some examples, Threshold_4 may be equal to or different from Threshold_1.

[0165] The CHO configuration information may be provided to the WTRU in one CHO configuration or multiple (e.g., independent) CHO configurations. In some examples, the WTRU may select a CHO configuration to monitor from among the multiple configurations. The selection may be based on the operating mode of the source and / or target.

[0166] In some examples, the target cells in the CHO configuration may include a list of target cells (e.g., a list of cells belonging to the same gNB as the current serving cell, such as handover candidates).

[0167] In some examples, a WTRU (e.g., or a group of WTRUs) may receive configuration information indicating (e.g., configured) to perform a HO (e.g., a group HO). The HO or group HO may be performed before a serving cell of the WTRU or the group of WTRUs is turned off (e.g., or enters a power saving mode). The HO or group HO may be triggered, for example, by L1 / L2 / L3 signaling (e.g., DCI, MAC CE, RRC), broadcast signaling, etc. The WTRU may be configured (e.g., for group HO) with a group identifier. The group HO signaling may be associated with the group identifier (e.g., DCI scrambled with the group identifier).

[0168] In some examples, the WTRU may reuse (e.g., all) the configuration for the old SpCell (e.g., after performing a handover). The reused configuration may replace the new SpPCell (e.g., without requiring explicit RRC reconfiguration for the CHO configuration).

[0169] In some examples, the WTRU may be configured to perform a HO (e.g., only perform a HO) if the target SpCell belongs to the same gNB / DU that also controls the source SpCell. The triggering information may be implicit (e.g., determined by reading system information of the target cell), explicit (e.g., the WTRU is configured with a list of cells belonging to the same gNB, such as a physical cell identity (PCI) list), or specified as a rule.

[0170] In some examples, the WTRU may (e.g., after performing a HO) update (e.g., implicitly update) the KgNB and / or integrity protection and encryption keys for the UP and / or CP based on the PCI, frequency, etc. of the new SpCell (e.g., without requiring explicit signaling for updating security keys).

[0171] In some examples, the WTRU may be configured with fallback or alternative cells (e.g., a PCI list) in the event that the current serving cell suddenly transitions to a power saving mode, is turned off, or moves to a different / specific availability state (e.g., sleep, hibernate, or off). The list of fallback alternative cells may be provided to the WTRU via dedicated information (e.g., in an RRC message), broadcast information (e.g., SIB information at the current serving cell at a time before the current serving cell was turned off, etc.). In some examples, for example, based on current WTRU conditions, such as configured bearers, UL / DL data rates, or measured channel conditions / coverage, the WTRU may not be able to detect the current serving cell (e.g., after the current serving cell is turned off), or the WTRU may detect that the current serving cell starts operating in a power saving mode / NES state that may not be suitable for the WTRU. The WTRU may search for (e.g., try to find) one or more indicated fallback alternative cells and attempt to perform a HO towards one of them (e.g., towards the best cell among the fallback cells, such as a cell that may meet a certain minimum signal level threshold). The WTRU may (e.g., when performing a HO) apply the HO operations described herein (e.g., deriving KgNB and associated UP / CP security keys, using the old SpCell configuration for the new cell, etc.). Each fallback cell may or may not involve a specific RRC reconfiguration. In some examples, the network may pre-configure a CHO-like configuration for one or more fallback cells (e.g., all or a subset) of the fallback cells (e.g., cells belonging to another gNB).

[0172] In some examples, the (e.g., legacy) behavior of reestablishing after not detecting the current serving cell (e.g., on RLF) may be modified. For example, the serving cell may be able to operate in a power save mode or may be shut down. For example, based on the inability to detect the current serving cell, the WTRU may explore other fallback mechanisms before resorting to reestablishment. For example, before resorting to reestablishment, the WTRU may attempt to connect / HO to a fallback cell, perform (e.g., any) CHO configuration, attempt to connect / HO to a cell of the same gNB that the WTRU is able to detect as having a good signal level, etc.

[0173] A sudden change in the operating mode of a serving cell (e.g., power saving mode, change in availability status, cell shut down, etc.) may cause multiple WTRUs served by that cell to perform handovers to a neighboring cell (e.g., almost simultaneously), which may cause problems (e.g., lack of RACH resources for initial access at the new cell). In some examples, handovers of WTRUs reacting to the sudden change may take precedence over WTRUs performing normal HO / CHO (e.g., source and target operating in normal mode).

[0174] In some examples, a set of RACH resources (eg, dedicated) may be allocated to a WTRU being handed over to a target cell. For example, a WTRU from a source cell in a normal operation mode may not use the set of resources.

[0175] In some examples, a WTRU in a cell that is being turned off or switched to a power saving mode / NES state may perform a gradual handover (e.g., from a time perspective). For example, the WTRU may detect that a power saving mode is turned on, or detect that a cell will soon be turned off or will transition to a different availability state. The WTRU may (e.g., based on detection / determination) perform one or more associated HO procedures described herein (e.g., after a delay). For example, the WTRU may detect within time (t1) that the current cell will be turned off or is transitioning to an NES state. The WTRU may (e.g., randomly) select a time between 0 and t1 (e.g., from a uniform random distribution) and initiate a handover at the selected time. The value of t1 may be configured or predetermined. The random selection of the HO initiation time may reduce the likelihood that all (e.g., similarly positioned) WTRUs will attempt to access the RACH resources at the target cell at the same time, for example, even if a contention-based RACH procedure will be applied for initial access.

[0176] In some examples, the WTRU may apply a RACH-free HO toward the target cell based on determining (e.g., upon detection) that the source cell will be shut down or switched to a power saving mode / NES state (e.g., if the source cell and the target cell belong to the same gNB).

[0177] The WTRU may perform cell reselection, for example, based on information about current or upcoming changes in the NES status of the serving cell and / or neighboring cells.

[0178] In some examples, a WTRU in an IDLE or INACTIVE state (eg, an IDLE / INACTIVE WTRU) may be configured not to perform cell reselection on a cell operating in a power save mode or NES state.

[0179] In some examples, an IDLE / INACTIVE WTRU may receive configuration information indicating (e.g., configured to) apply a (e.g., specific, selected, (pre-)configured) negative offset to the signal level of a neighboring cell that may operate in a power save mode.

[0180] In some examples, if the WTRU detects that the current serving cell has begun operating in a power saving mode, the IDLE / INACTIVE WTRU may receive configuration information indicating (e.g., configured to) apply a (e.g., a specific, selected, (pre-)configured) positive offset to the signal level of a neighboring cell.

[0181] In some examples, an INACTIVE WTRU may receive configuration information indicating (e.g., configured to) apply a negative offset or a positive offset to a signal level of a neighboring cell according to a saved WTRU context (e.g., as described herein). For example, if the WTRU has a bearer that is configured to require a high data rate and / or high latency, the WTRU may apply one or more offsets during cell reselection measurements / evaluations, for example, so that cells operating in normal mode may be prioritized.

[0182] Mobility can be triggered by loss of coverage in the NES.

[0183] The WTRU may use and / or be configured with alternative thresholds for mobility, for example, if the source cell and / or the target cell are determined to be in one or more availability states, such as alternative values ​​for an A3 event or an A5 event, the alternative thresholds may be used. For example, if the source cell and / or the target cell are determined to be in one or more availability states, an NES state, or a reduced power state, the WTRU may apply a (pre-)configured or (pre-)determined offset to the default mobility threshold (e.g., an offset that is added or subtracted from an A3 event threshold or an A5 event threshold that has been configured in the default state).

[0184] In some examples, based on (e.g., according to) determining that the source cell is in a PA power efficient state or NES state, the WTRU may (e.g., then) apply or use an alternative mobility threshold and / or apply a mobility threshold offset for NES and / or initiate a mobility procedure. The WTRU may determine that the serving cell / source cell is in a reduced power state or NES state, for example, based on at least one of the following ways.

[0185] For example, the WTRU may determine that the serving cell / source cell is in a reduced power state or NES state by determining that the DL power is reduced for one or more downlink channels and / or signals (eg, SSB, RS, or CSI-RS).

[0186] The WTRU may, for example, receive a signal or indication from the NW (e.g., Figure 5as shown) to determine that the serving cell / source cell is in (e.g., is entering) a reduced power state or NES state, which may include receiving an indication from the network regarding power reduction, receiving an indication from the network regarding a change in availability status associated with the source cell or the target cell, and / or receiving or detecting an SSB associated with the NES (e.g., a clipped SSB, a PSS-only SSB).

[0187] For example, based on a determination / indication that the availability state of the source cell or target cell has changed, and / or based on measured channel conditions of the source cell (e.g., L1 or L3 RSRP) being below a threshold, the WTRU may determine that the serving cell / source cell is in a reduced power state or NES state.

[0188] The WTRU may determine that the serving cell / source cell is in a reduced power state or NES state, for example, based on channel measurements. For example, the WTRU may measure the channel condition (e.g., L1 or L3 RSRP) of the target cell as being above a threshold, and / or the WTRU may measure a change in the channel condition (e.g., L1 or L3 RSRP) of the source cell as being greater than a threshold (e.g., the WTRU may determine that the source cell is entering the NES state based on determining that the change between a first measurement and a second measurement associated with the source cell exceeds a threshold). The WTRU may receive configuration information (e.g., be (pre)configured with) or may (pre)determine a period of time to determine the change in the measurement value.

[0189] The WTRU may determine that the serving cell / source cell is in a reduced power state or NES state, for example, based on determining that the TRP in the source cell / serving cell is muted for NES.

[0190] For example, based on detecting a change in measured channel conditions associated with a spatial element greater than a threshold (e.g., L1 RSRP of a CSI resource associated with a TRP), the WTRU may determine that the serving cell / source cell is in a reduced power state or NES state.

[0191] The WTRU may determine that the serving cell / source cell is in a reduced power state or NES state, for example, based on determining that the PA of the serving cell is operating in a non-linear state.

[0192] The WTRU may measure (e.g., start measuring) the SBS and / or RS associated with the target cell based on (e.g., based on) detection of one or more events described herein (e.g., SBS or CSI-RS configured for mobility), and / or may evaluate the configured CHO condition. The WTRU may measure (e.g., start measuring) the SBS and / or RS associated with a different TRP in the same cell based on (e.g., based on) detection of one or more events described herein (e.g., SBS or CSI-RS configured for a different TRP). The WTRU may add one or more triggers (e.g., as described herein) to perform conditional handover on any configured candidate.

[0193] The WTRU may track time (e.g., start a timer) based on (e.g., based on) detection of any of one or more events (e.g., mobility timer T304, a timer similar to T304, or a NES cell validity timer). In an example, the timer may be an existing T304 timer or a new timer. The WTRU may start tracking time (e.g., via a timer) based on (e.g., based on) performing HO, initiating a RA for HO at a target cell, and / or evaluating (e.g., starting to evaluate) a CHO condition at a candidate cell. For example, if the cell is in an NES state, the WTRU may scale the duration (e.g., to a value configured for T304 or to use an alternative configured NES value for the timer), for example, based on / based on starting to track the time (e.g., via a timer). The WTRU may initiate an RLF procedure, an SCG failure procedure, reply to connect to a source cell, and / or send a NES wake-up request, for example, based on (e.g., based on) the duration lapses (e.g., timer expiration).

[0194] The WTRU may receive an indication of a (e.g., precise) time (e.g., or a time period until that time) at which power at a serving cell is reduced. The WTRU may determine (e.g., may be configured to assume) a reduced power NES state, and / or a different availability state may be applied after a period of time has elapsed since / after receiving (e.g., from a gNB) an indication of an availability state change and / or a reduced power state. The WTRU may (e.g., periodically) determine the power of a serving cell (e.g., or a coverage level determined from cell measurements) from a semi-static configuration. For example, the WTRU may (e.g., be configured to) periodically measure RS and / or SSB, which may be configured for a WTRU with NES capability. The WTRU may determine from measured channel conditions that the serving cell is in a reduced power state (e.g., or NES state). The determination may be based on the measured channel conditions being less than a configured threshold, and / or based on received SSBs and / or RSs (e.g., based on a received sequence, RS, or SSB index). The WTRU may apply an offset, for example, based on an indication or determination that PA power is reduced.

[0195] The WTRU may monitor for detection of SSBs or RSs associated with NES, e.g., corresponding to a new PCI. The WTRU may determine that the serving cell is in an NES state or a reduced power state based on (e.g., according to) detection of SSBs or RSs corresponding to the NES PCI. The NES PCI may point to an alternative cell. The WTRU may determine the cell to be switched to based on the value of the detected new NES PCI. The WTRU may perform mobility to a target cell or a CHO candidate cell based on (e.g., according to) detection of the PCI, e.g., based on / based on satisfying other pre-existing mobility or CHO conditions (e.g., a measurement of a channel condition at the target cell being above a threshold). The WTRU may monitor one or more PCIs (e.g., a PCI of a source cell, a PCI of a target cell, and / or a NES PCI). The WTRU may perform associated measurements, e.g., for a configured duration and / or based on (e.g., according to) detection of one or more triggers (e.g., as described herein). For example, if the cell is the same source cell with a reduced power state, the WTRU may switch to a cell with an SSB corresponding to the NES PCI.

[0196] Mobility in an inactive state may be triggered by a data transmission such as a small data transmission (SDT). In some examples, the WTRU may be in an inactive state configured with small data transmission / reception. The WTRU may receive a handover command, an RRC reconfiguration, and / or an indication of one or more candidate cells to switch to a small data TB in a PDSCH or a portion of a multiplexed MAC CE. The WTRU may (e.g., determine) to switch to another candidate cell, for example, based on attributes of a small data transmission payload received in an inactive state, based on (e.g., according to) receiving an availability state switching command from the network (e.g., during an SDT session), and / or based on a determined NES state associated with a cell being switched via an availability state.

[0197] Inter-TRP switching can occur within a cell.

[0198] In some examples, the WTRU may receive an indication that reception of PDCCH transmissions and / or PDSCH transmissions using a transmission configuration index (TCI) state is to be turned off (e.g., or turned on). The indication may be included in WTRU group common signaling (such as DCI received in a WTRU group common search space) and / or in system information. The indication may be an indication of an availability state or may provide an indication of an availability state. The WTRU may receive (e.g., signaled indication) an association between the TCI state and a TCI state group identifier (e.g., or a TRP identifier). The WTRU may (e.g., alternatively) receive (e.g., signaled indication) an association between the TCI state and the availability state. The signaling may be or may include an information element (IE) or a MAC CE in a TCI state configuration. The WTRU may (e.g., then) receive (e.g., from WTRU group common signaling) an indication of the TCI state group identifier and / or an indication that transmission is to be turned on or off. The (e.g., exact) time at which transmission may be turned off (e.g., or turned on) may be a fixed or configured time after receiving the signaling. The signaling may (eg, alternatively) include an indication of the time at which transmission may be switched off (eg, or on), eg, in terms of a number of symbols or time slots.

[0199] The WTRU may (e.g., based on receiving an indication that reception using the TCI state is to be turned off) stop receiving PDCCH using the TCI state and / or may receive PDCCH from an alternate TCI state (e.g., at the indicated time). The alternate TCI state to be used may be configured for each TCI state that is subject to being turned off. The WTRU may (e.g., also) stop monitoring beam failure detection resources associated with the TCI state to be turned off and / or may monitor (e.g., start monitoring) beam failure detection resources associated with the alternate TCI state.

[0200] A handover may be performed to a cell that is sleeping or in NES state.

[0201] The WTRU may determine the availability status of the target cell, for example, before performing a handover procedure to the target cell (e.g., before initiating a RA procedure for the target cell, before synchronizing with the target cell, and / or before sending on an uplink channel or signal). The WTRU may determine the availability status of the target cell, for example, based on an indication received in a handover command (e.g., as part of a handover command) or an indication from a source cell. For example, the RRC reconfiguration message may indicate the availability status associated with the target cell, the associated uplink resources, the associated DRX cycle, the associated PRACH resources, the associated SSB or alternative SSB cycle, and / or a subset of SSBs sent at the target cell. The WTRU may determine the availability status of the target cell, for example, based on broadcast or SI signaling received from the cell itself (e.g., the target cell). For example, the WTRU may obtain system information (SI) or other SI to determine the availability status of the cell. For example, the availability of the cell may be sent via PBCH or SI broadcast signaling. The WTRU may determine (e.g., implicitly) the availability state and / or DL ​​power operation state of the target cell (e.g., reduced coverage, NES power efficient PA operation), for example, based on reception of the SBS on the cell and / or based on its attributes. For example, the WTRU may determine the availability state, the NES state, and / or the power operation state based on (e.g., according to) reception of SSBs associated with the NES, the SSBs associated with the NES may include, for example, one or more of: a clipped SSB, a PSS-only SSB, an SSB periodically transmitted using the NES, and / or a subset of SSBs corresponding to the NES state.

[0202] The WTRU may determine the availability status at a source cell / serving cell, a candidate cell for HO, an alternative cell, and / or any other cell, for example, using one or more of the procedures described herein.

[0203] The WTRU may be configured with a NES cell validity time (e.g., via a timer). The time (e.g., timer) may be associated with one or more availability states associated with a cell. For example, the time (e.g., timer) may be configured per carrier or per BWP. For example, after receiving / detecting a DL signal of a cell (e.g., with a signal strength above a threshold), the WTRU may start tracking the NES cell validity time (e.g., via a timer). The WTRU may assume a given availability state (e.g., ON for a period of time after SSB detection or presence indication / signal) (e.g., while the timer is running). The WTRU may perform measurements (e.g., on SSB or RS), for example, using default (e.g., legacy) settings while the time is being tracked (e.g., the timer is running). The WTRU may determine (e.g., or assume) whether the cell is in a different NES / availability state (e.g., based on / according to the expiration of the NES cell validity time (e.g., via a timer)). The WTRU may check system information (SI), availability state change command, and / or detect presence signals associated with cells for NES (e.g., before resuming regular measurements). The WTRU may use UL / DL resources associated with the cell, for example, using a default non-NES state. The WTRU may restart the time (e.g., timer), for example, based on (e.g., according to) determining an availability state change for the associated cell (e.g., if the cell is not in the NES state), receiving a DL signal or channel from a channel, receiving a HO command from another cell to HO to the associated cell, and / or detecting an SSB or RS associated with the cell. The WTRU may trigger an RLF or SCG failure procedure when the time (e.g., timer) expires.

[0204] Random access (RA) can be performed in a cell that is sleeping or in NES state.

[0205] The WTRU may receive (e.g., as part of an RRC reconfiguration / HO command) an indication of a timing or time period for measuring the SBS at the target cell, and / or a value (e.g., a timer) to be applied to the NES cell validity time. The WTRU may receive (e.g., as part of an RRC reconfiguration / HO command or other SI) an indication of an applicable RO at the target cell or serving cell, applicable SSB / CSI-RS opportunities, NES Candidate BeamRSList for BFR, and / or a differentiated / NES SSB to RO mapping, which may be applied, for example, based on (e.g., according to) a determination that the cell performing the RA is in a particular NES state.

[0206] A random access (RA) may be initiated on a cell in an NES state (e.g., including a RA performed at a target cell for mobility). The WTRU may initiate a RA procedure for coverage enhancement, for example, by selecting a PRACH resource associated with msg1 and / or msg3 repetition, DFT-s-OFDM, and / or CE spectrum shaping waveform for Msg3. For example, if there is an indication that the target cell is in a given NES state or reduced PA power state, if there is an indication to perform the RA using coverage enhancement (e.g., as part of the command), and / or if RA resources associated with NES are indicated (e.g., as part of the command), and / or if an RRC reconfiguration is issued by the source cell, the WTRU may perform a RA with coverage enhancement at the target cell (e.g., based on receipt of a field in a HO command). The WTRU may be configured with alternative parameters that may be used for a RA initiated on a cell in an NES state. The parameters may include, for example, one or more of the following parameters: Tx power, power ramp step size, backoff duration, PRACH resources, and / or preambleTransMax. For example, if the cell on which the RA is performed is determined to be in one or more availability / NES states, the WTRU may be configured with alternative values ​​that may be used for the random access response (RAR) window and / or contention resolution timer.

[0207] The WTRU may receive configuration information indicating a certain preamble or RO partition associated with a NES (e.g., configured (e.g., in a contention-free RACH (CFRA))). For example, if the WTRU receives a PDCCH order with a PRACH partition, the WTRU may determine (e.g., assume) that a NES SSB period (e.g., or NES SSB) is used and / or may initiate a RA procedure using NES parameters for RA (e.g., Tx power, power ramp step size, etc.). For example, an availability state associated with a target cell may be indicated via a PDCCH order. The WTRU may (e.g., therefore) use (e.g., only use) PRACH resources that are applicable to the active availability state of the cell.

[0208] A WTRU may receive configuration information indicating (e.g., configured with) one or more (e.g., dedicated) CFRA resources (e.g., via dedicated signaling, such as rach-ConfigDedicated). For example, if the WTRU has buffered data from one or more logical channels (LCHs) or data radio bearers (DRBs) that may be associated with low latency, associated with a QoS flow (e.g., configured within a latency budget below a threshold), and / or if the LCH with the buffered data is configured to allow the WTRU to use the CFRA resources, then the CFRA resources may be used.

[0209] For example, based on / according to a determination that the cell on which the RA is performed is in an NES state, the WTRU may defer preamble transmission if none of the SSBs are measured to have an RSRP above a configured threshold during the PRACH resource selection portion of the RA procedure. The WTRU may defer RACH preamble transmission, for example, until an SSB is measured to be above an RSRP threshold and / or until a NES SSB / PRACH opportunity occurs after a DL signal detection from the same cell or gNB. For example, if a preamble is not transmitted due to an NES state and / or due to no SSB being detected above a configured threshold, the WTRU may (e.g., therefore) not increment a preamble transmission counter and / or a preamble power ramp counter. For example, if an SSB is detected to have a signal strength above a configured threshold (e.g., within a certain timer period before the RO), the WTRU may increment a preamble transmission counter and / or a preamble power ramp counter (e.g., only). A WTRU (eg, in IDLE or inactive state) may avoid using a PRACH opportunity after detecting an SSB failure above an (eg, configured) RSRP threshold.

[0210] RACH can be initiated by NES group switching.

[0211] The RA procedure may be initiated by a handover caused by a NES (e.g., based on one or more CHO conditions or mobility methods, HO caused by a coverage loss due to a NES, and / or HO caused by a cell shutdown). The WTRU may be configured with a RA type and / or a PRACH resource type to be used, which may include, for example, one or more of the following: an indication of whether the PRACH resource is a 2-step RA resource or a 4-step RA resource, an indication of whether the PRACH resource is a coverage enhancement, an indication of whether the PRACH resource is associated with a given slice, an indication of one or more applicable RRC states, and / or an indication of an alternative value for msgA-RSRP-Threshold.

[0212] The RA procedure may be initiated by a handover caused by NES (e.g., based on one or more CHO conditions, HO caused by a coverage loss due to NES, and / or HO caused by cell shutdown). For example, while a timer (e.g., T304, a new NES mobility timer, and / or a NES cell validity timer) is running, the WTRU may use contention-based resources to access the target cell. For example, if the timer expires, after multiple CBRA preambles are sent, and / or if the CBRA procedure is not (e.g., not yet) successful (e.g., RAR is not received and / or contention resolution is not received), the WTRU may fall back to CFRA resources.

[0213] For example, a WTRU that is in RRC inactive may initiate a RA to resume a suspended connection and / or an SDT may be (pre)configured or (pre)determined to use 2-step CBRA resources or CFRA resources. The WTRU may determine whether to use 2-step RA, 4-step RA, CBRA, or CFRA, for example, based on at least one of the following: the type of WTRU, WTRU capabilities (e.g., Redcap / URLLC), the type of DRB to be resumed (e.g., SDT DRB, DRB configured with low-latency packet delay budget (PDB)), the NES group of the WTRU, QoS, latency requirements, power constraints, availability states associated with the source cell and the target cell, and / or upcoming state transition timing.

[0214] The WTRU may receive an indication (e.g., from a gNB) indicating which carrier type to use (e.g., non-supplemental uplink (SUL) or SUL), which RACH resources to use, and / or which type of RACH to use (e.g., 2-step versus 4-step).

[0215] Carrier switching and / or low energy operation may be provided.

[0216] SCell operation can be achieved without SSB transmission / cross-carrier synchronization.

[0217] For example, if an SSB (e.g., or a subset of an SSB) is not detected (e.g., if the SS-RSRP is below a configured threshold and / or if the WTRU is unable to or does not detect a sequence associated with a PSS and / or SSS transmission), the WTRU may acquire downlink timing of a secondary serving cell, perform procedures associated with initial access, perform SI acquisition, and / or perform Pcell-based synchronization.

[0218] The WTRU may receive (e.g., from a Pcell) a configuration or reconfiguration of a Scell ​​availability status and / or associated SSB, CSI-RS. For example, the WTRU may receive a reconfiguration of the SSB periodicity of the Scell ​​and / or an indication of whether the SSB periodicity of the Scell ​​is sent from the Pcell or another associated cell (e.g., another Scell ​​or a cell in a different cell group). For example, if the Pcell and / or other associated cells are used to perform initial access and / or acquire DL timing, the WTRU may receive an indication and / or configuration that a downlink timing offset will be used for Scell ​​DL timing. For example, the offset value may be scaled or selected (e.g., determined, selected) based on the frequency gap between the center frequency of the Scell ​​and the cell on which DL synchronization is performed (e.g., an associated Pcell).

[0219] For example, based on one or more of the following conditions, the WTRU may use resources and / or activate a secondary cell (Scell) without an SSB. For example, if none of the conditions are met, the WTRU may determine that the Scell ​​is not active, is dormant, or is not detected. The WTRU may not perform regular measurements on the Scell ​​and / or may not perform uplink or downlink transmissions on the Scell.

[0220] For example, if the WTRU is synchronized with a Pcell or SpCell, the WTRU may use resources without SSB and / or may activate a secondary cell.

[0221] For example, if the Scell ​​is in the same frequency band as the Pcell and / or the cell from which it is synchronized, the WTRU may use resources without SSB and / or activate the secondary cell.

[0222] For example, if the separation in the frequency domain between the Scell ​​and the Pcell and / or the cell from which synchronization is obtained does not exceed a predefined or configured maximum frequency gap, the WTRU may use resources without SSB and / or activate a secondary cell.

[0223] For example, if the WTRU determines a change in availability status associated with a Scell, a Pcell, a NES Pcell, and / or another cell from which synchronization is obtained, the WTRU may use resources and / or activate a secondary cell without SSB. For example, based on receiving an indication (e.g., from a NW) indicating a certain NW activity level on a Pcell or an associated Scell, or based on detecting a presence signal associated with a Pcell or Scell, the WTRU may use a Scell ​​without SSB.

[0224] For example, based on receipt of an indication (e.g., from a gNB), for example, within a received time period (such as when an Scell ​​deactivation timer or another timer is running), the WTRU may use resources and / or activate a secondary cell without an SSB. For example, the indication may be DCI or PDCCH signaling, for example, indicating one or more parameters for cross-carrier synchronization.

[0225] For example, if the WTRU is scheduled (eg, cross-carrier) to use or monitor DL ​​and / or UL resources on a Scell, the WTRU may use the resources and / or activate a secondary cell without an SSB.

[0226] For example, if the WTRU is in DRX active time and / or duration for Scell ​​and / or other related cells (e.g., Pcell, NES Pcell and / or cells synchronized therefrom), the WTRU may use resources and / or activate a secondary cell without SSB.

[0227] For example, if a time (eg, a timer) has expired (eg, a beam failure detection timer), the WTRU may use resources without SSB and / or activate a secondary cell.

[0228] For example, if one or more conditions (e.g., as described herein) are not met, the WTRU may deactivate the SCell without SSB. For example, if one or more of the conditions are not met, the WTRU may stop monitoring and / or measuring DL signals (e.g., PDCCH, RS, SSB) and / or resources (e.g., PDSCH) associated with the SCell without SSB transmission (e.g., at least for the period when the SCell operates without SSB transmission). For example, if one or more of the conditions are not met, the WTRU may stop using UL resources (e.g., PRACH, PUCCH, PUSCH) and / or stop sending uplink signals (e.g., UCI, PRACH, SRS, pSRS) associated with the SCell without SSB transmission (e.g., at least for the period when the SCell operates without SSB transmission).

[0229] NES PCell switching can be realized.

[0230] In some examples (e.g., deployment scenarios), one or more (e.g., some) WTRUs in a service area may have a different PCell than other WTRUs. For example, one or more WTRUs may have different PCells and the same SCell. In some examples, the PCell for one WTRU may be the SCell for another WTRU served by the same gNB. The WTRU may receive a PCell switching L1 indication (e.g., a group common command or DCI) and / or L2 signaling (e.g., broadcast signaling, MAC CE, or PDSCH). The PCell switching indication may indicate that multiple (e.g., all) WTRUs served by a cell group consider a certain (pre-)configured or (pre-)determined cell as a PCell (e.g., a cell on which certain SSBs are sent). For example, the WTRU may (e.g., based on / according to receiving a PCell switching command) activate a serving cell x (e.g., a NES PCell) and consider it as a primary cell, and / or may consider another cell y (e.g., which is a PCell to a SCell) as a primary cell. In some examples, x and y may be configured in RRC and / or broadcast signaling. For example, the WTRU may perform a PCell switch if at least one of the following conditions is met: (a) successfully receiving a PCell switch command, (b) decoding SSBs and / or CSI-RS associated with the new active PCell (e.g., NES PCell), (c) measuring channel conditions above a configured threshold, for example, on the new active PCell (e.g., NES PCell), and / or (d) a timer and / or time period expires without receiving a DL signal from the cell (e.g., the cell may be considered an SCell or deactivated based on / according to the expiration of a timer). For example, if the WTRU erroneously detects DL signaling from a new PCell (e.g., NES PCell), the WTRU may fall back to using the last serving PCell.

[0231] For example, based on / upon receipt of a NES PCell handover command, the WTRU may receive an indication from the gNB to reestablish security keys and / or indicate which DL and / or UL resources may be used on the activated PCell and / or other activated NES cells. The WTRU may reuse a subset of configurations configured from the SpCell for the NES PCell and / or other activated cells for NES purposes.

[0232] Although the features and elements described above are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or in various combinations with or without the other features and elements.

[0233] Although the implementation described herein may consider 3GPP specific protocols, it should be understood that the implementation described herein is not limited to such scenarios and is applicable to other wireless systems. For example, although the solution described herein considers LTE, LTE-A, New Radio (NR) or 5G specific protocols, it should be understood that the solution described herein is not limited to such scenarios and is also applicable to other wireless systems.

[0234] The processes described above may be implemented in a computer program, 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 (sent via wired and / or wireless connections) 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, built-in hard disks and removable disks), magneto-optical media, and / or optical media (such as compact disk (CD)-ROM disks and / or digital versatile disks (DVDs)). A processor associated with the software may be used to implement a radio frequency transceiver for a WTRU, terminal, base station, RNC, and / or any host computer.

Claims

1. A wireless transmit / receive unit (WTRU), the wireless transmit / receive unit (WTRU) comprising: A processor, the processor being configured to: receiving network energy saving (NES) specific configuration information including a set of switching candidates and conditions for NES conditional switching; Determine that the source cell is entering the NES state; Determining that a handover cell from the set of handover candidates satisfies a condition for the NES conditional handover; as well as Based at least on a determination that the source cell is entering a NES state and a determination that the handover cell satisfies the conditions for the NES conditional handover, a handover to the handover cell is performed.

2. The WTRU of claim 1 , wherein: The processor is further configured to: An indication is received, and wherein it is determined based on the received indication that the source cell is entering a NES state.

3. The WTRU of claim 2, wherein: The indication is received from the source cell via an L1 broadcast signal or an L2 broadcast signal.

4. The WTRU of claim 1 , wherein: The processor is further configured to receive an indication of a time associated with the source cell entering the NES state, and wherein the determination that the source cell is entering the NES state is associated with the indicated time.

5. The WTRU of claim 1 , wherein: The processor is further configured to: determining a first measurement associated with the source cell; and Determining that the first measurement associated with the source cell is less than a threshold, wherein the determination that the source cell is entering an NES state is based on determining that the first measurement associated with the source cell is less than the threshold.

6. The WTRU of claim 1 , wherein: The processor is further configured to: determining a first measurement and a second measurement, wherein the first measurement and the second measurement are associated with the source cell; and Determining that a difference between the first measurement and the second measurement is greater than a threshold, wherein the determination that the source cell is entering an NES state is based on determining that the difference between the first measurement and the second measurement is greater than the threshold.

7. The WTRU of claim 1 , wherein: The NES state is activation of cell discontinuous transmission (DTX) or cell deactivation.

8. The WTRU of claim 1 , wherein: The configuration information indicates a first handover candidate and a second handover candidate, wherein the first handover candidate is indicated as being prioritized over the second handover candidate, wherein the handover cell is the first handover candidate, and wherein the processor is further configured to: Determine that the second handover candidate satisfies the conditions for the NES conditional handover, wherein the second handover candidate and the first handover candidate are capable of being used for selection, wherein the second handover candidate is another handover cell, and wherein the handover performed to the handover cell is also indicated as taking precedence over the second handover candidate based on the first handover candidate.

9. A method comprising: receiving network energy saving (NES) specific configuration information including a set of switching candidates and conditions for NES conditional switching; Determine that the source cell is entering the NES state; Determining that a handover cell from the set of handover candidates satisfies a condition for the NES conditional handover; as well as Based at least on a determination that the source cell is entering a NES state and a determination that the handover cell satisfies the conditions for the NES conditional handover, a handover to the handover cell is performed.

10. The method according to claim 9, further comprising: An indication is received, and wherein it is determined based on the received indication that the source cell is entering a NES state.

11. The method according to claim 10, wherein: The indication is received from the source cell via an L1 broadcast signal or an L2 broadcast signal.

12. The method according to claim 9, wherein: The method further comprises: An indication of a time associated with the source cell entering the NES state is received, and wherein a determination that the source cell is entering the NES state is associated with the indicated time.

13. The method according to claim 9, wherein: The method further comprises: determining a first measurement associated with the source cell; and Determining that the first measurement associated with the source cell is less than a threshold, wherein the determination that the source cell is entering an NES state is based on determining that the first measurement associated with the source cell is less than the threshold.

14. The method according to claim 9, wherein: The method further comprises: determining a first measurement and a second measurement, wherein the first measurement and the second measurement are associated with the source cell; and Determining that a difference between the first measurement and the second measurement is greater than a threshold, wherein the determination that the source cell is entering an NES state is based on determining that the difference between the first measurement and the second measurement is greater than the threshold.

15. The method according to claim 9, wherein: The NES state is activation of cell discontinuous transmission (DTX) or cell deactivation.

16. The method according to claim 9, wherein: The configuration information indicates a first handover candidate and a second handover candidate, wherein the first handover candidate is indicated as being prioritized over the second handover candidate, wherein the handover cell is the first handover candidate, and wherein the method further comprises: Determine that the second handover candidate satisfies the conditions for the NES conditional handover, wherein the second handover candidate and the first handover candidate are capable of being used for selection, wherein the second handover candidate is another handover cell, and wherein the handover performed to the handover cell is also indicated as taking precedence over the second handover candidate based on the first handover candidate.

Images