Method for relaxing radio link monitoring requirements in wireless systems

Abstract

To provide a method for relaxation operation.SOLUTION: A wireless transmit / receive unit (WTRU) may comprise a processor and memory. The processor and memory may be configured to receive configuration information indicating measurement relaxation criteria for radio link monitoring (RLM) or beam failure detection (BFD) and a prohibit time period for reporting a measurement relaxation state. The WTRU may determine that the measurement relaxation state of the WTRU has changed based on the measurement relaxation criteria. The WTRU may determine that the prohibit time period has ended. The WTRU may send a report based on the determination that the measurement relaxation state has changed and the determination that the prohibit time period has ended. The report may include an indication of the measurement relaxation state.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] (Related Application) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 292,293, filed on Dec. 21, 2021, the entire contents of which are incorporated herein by reference.

Background Art

[0002] In 5G New Radio, a wireless transmit / receive unit (WTRU) monitors the downlink radio link quality based on a reference signal configured as an RLM-RS resource (s) to detect the downlink radio link quality of the primary cell (PCell) as well as the primary and secondary cells (PSCell). The configured radio link monitoring radio signal (RLM-RS) resources can be all synchronization signal blocks (SSBs), or all CSI-RSs, or a mixture of SSBs and channel state information resource signals (CSI-RSs). The WTRU does not need to perform RLM outside of the active downlink bandwidth part (DL BWP). Similarly, the WTRU evaluates the downlink radio link quality of the serving cell to detect beam blockages.

Summary of the Invention

[0003] In one or more methods, systems, and / or apparatuses, there can be a relaxation of radio link monitoring in a wireless system. In some cases, MAC CE or L1 signaling can be used to report dynamically provided network control on the uplink and / or to enable / disable on the downlink. In some cases, a shortened uplink report indicating a simple binary condition can be used regarding whether reporting criteria or relaxation criteria are met. For example, the report can be a single bit. For example, the report can include a limited number of multiple bits to provide more information, such as whether individual criteria are met. In some cases, dynamic downlink control can be used with simple on / off and / or up / down commands from the network indicating one or more measurement requirements.

[0004] A wireless transmit / receive unit (WTRU) may comprise a processor and a memory. The processor and the memory may be configured to receive configuration information indicating measurement relaxation criteria for radio link monitoring (RLM) or beam failure detection (BFD) and a prohibited time period for reporting a measurement relaxation state. The WTRU may be able to determine that the measurement relaxation state of the WTRU has changed based on the measurement relaxation criteria. The WTRU may be able to determine that the prohibited time period has ended. The WTRU may be able to transmit a report based on the determination that the measurement relaxation state has changed and the determination that the prohibited time period has ended. The report may include an indication of the measurement relaxation state.

[0005] The WTRU may be able to start the prohibited time period when the WTRU transmits a report. The WTRU may be prohibited from changing the measurement relaxation state while the prohibited timer is running.

[0006] The report may be able to indicate whether the WTRU is in a measurement relaxation state or that the WTRU is not in a measurement relaxation state. The indication of the measurement relaxation state may be specific to a first cell. The report may further include an indication of the measurement relaxation state specific to a second cell. The WTRU may be able to receive signaling that enables the WTRU to transmit a report. In some examples, the signaling that enables the WTRU to transmit a report may be the same signaling that provides the prohibited time period.

[0007] The configuration information may indicate the prohibited time period among a plurality of prohibited time periods.

[0008] The WTRU may be able to perform RLM and / or BFD measurements using a first periodicity when the WTRU is not in a measurement relaxation state. The WTRU may be able to perform RLM and / or BFD measurements using a second periodicity when the WTRU is in a measurement relaxation state.

[0009] The WTRU can determine to enter a measurement relaxation state based on the power measurement value exceeding a power threshold. The power threshold can include one or more of a SINR threshold, an RSRP threshold, an RSSI threshold, or an RSRQ threshold. The WTRU can determine to enter a measurement relaxation state based on the variation of the power measurement value being less than a variation / mobility threshold. The mobility threshold can include a change in RSRP and / or a cell change count within a specific time limit. The WTRU can determine to exit the measurement relaxation state based on the power measurement value being less than the power threshold.

[0010] The method implemented by the WTRU can include receiving configuration information indicating measurement relaxation criteria for radio link monitoring (RLM) or beam failure detection (BFD) and a prohibited time period for reporting the measurement relaxation state. The method can include determining that the measurement relaxation state of the WTRU has changed based on the measurement relaxation criteria. The method can include determining that the prohibited time period has ended. The method can include transmitting a report based on the determination that the measurement relaxation state has changed and the determination that the prohibited time period has ended. The report can include an indication of the measurement relaxation state.

[0011] The method can further include starting the prohibited time period when the WTRU transmits a report. The method can further include prohibiting a change in the measurement relaxation state while a prohibited timer that can track the prohibited time period is operating.

[0012] The report can indicate whether the WTRU is in a measurement relaxation state or that the WTRU is not in a measurement relaxation state.

[0013] The method can include indicating that the measurement relaxation state is specific to a first cell. The method can include indicating that the measurement relaxation state is specific to a second cell.

[0014] The method can include receiving signaling that enables the WTRU to send a report. The configuration information may indicate a prohibited time period of the plurality of prohibited time periods.

[0015] The method can include performing RLM or BFD measurements using a first periodicity when the WTRU is not in a measurement relaxation state. The method can include performing RLM or BFD measurements using a second periodicity when the WTRU is in a measurement relaxation state. The method may include determining to enter a measurement relaxation state based on a power measurement value exceeding a power threshold. The method may include determining to exit a measurement relaxation state based on a power measurement value falling below a power threshold.

Brief Description of the Drawings

[0016] A more detailed understanding can be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which like reference numerals in the figures indicate like elements.

[0017]

Figure 1A

Figure 1B

Figure 1C

Figure 1D

Figure 2

Figure 3

Figure 4

[0018] FIG. 1A illustrates an exemplary communication system 100 in which one or more of the 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 a plurality of wireless users. The communication system 100 may enable a plurality of wireless users to access such content through sharing of system resources including wireless bandwidth. For example, the communication system 100 may use 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 discrete Fourier transform Spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filter type OFDM, filter bank multicarrier (FBMC), etc.

[0019] As shown in Figure 1A, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112. However, it will 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 WTRUs 102a, 102b, 102c, 102d, any of which may be referred to interchangeably as a station (STA), may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile telephone subscriber units, subscriber-based units, pager, mobile telephone, personal digital assistant (PDA), smartphone, laptop, netbook, personal computer, wireless sensor, hotspot or Mi-Fi device, Internet of Things (IoT) device, watch or other wearable, head-mounted display (HMD), vehicle, 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 processing chain context), home electronics devices, devices operating in commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be referred to interchangeably as a UE.

[0020] The communication system 100 may also include base station 114a and / or base station 114b. Each of base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks such as CN 106, Internet 110, and / or other network 112. By way of example, base stations 114a, 114b may be base transceiver stations (BTSs), Node Bs, eNode Bs (eNBs), Home Node Bs, Home eNode Bs, next-generation Node Bs such as gNode Bs (gNBs), new radio (NR) Node Bs, site controllers, access points (APs), wireless routers, and the like. Although base stations 114a, 114b are each illustrated as a single element, it will be understood that base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0021] Base station 114a may be part of RAN 104, which may also include other base stations such as a base station controller (BSC), a radio network controller (RNC), a relay node, and / or network elements (not shown). Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals at one or more carrier frequencies that may be referred to as a cell (not shown). These frequencies may be in an authorized spectrum, an unlicensed spectrum, or a combination of an authorized spectrum and an unlicensed spectrum. A cell may provide wireless service coverage to a specific geographic area that may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver per sector of the cell. In one embodiment, base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers per sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0022] Base stations 114a, 114b may communicate with one or more of WTRUs 102a, 102b, 102c, 102d via air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). Air interface 116 may be established using any suitable radio access technology (RAT).

[0023] More specifically, as described above, the communication system 100 can be a multiple access system, and can use one or more channel access methods such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a of the RAN 104 and the WTRUs 102a, 102b, 102c can implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA) that can establish the air interface 116 using wideband CDMA (WCDMA (registered trademark)). WCDMA can include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High-Speed Downlink Packet Access (HSDPA) and / or High-Speed Uplink Packet Access (HSUPA).

[0024] In one embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0025] In one embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement radio technologies such as NR radio access, which can establish the air interface 116 using NR.

[0026] In one 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 implement LTE radio access and NR radio access together, for example, using the dual connectivity (DC) principle. Accordingly, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions that are transmitted between multiple types of base stations (e.g., eNBs and gNBs).

[0027] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement wireless 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), GSM EDGE (GERAN), etc.

[0028] The base station 114b in FIG. 1A can be, for example, a wireless router, a Home Node B, a Home eNode B, or an access point, but can utilize any suitable RAT to facilitate wireless connections in a local area such as an office, home, vehicle, campus, industrial facility, aerial corridor (e.g., for use by drones), a location such as a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d can implement a wireless technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d can implement a wireless 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 can utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a pico cell or a femto cell. As shown in FIG. 1A, the base station 114b can have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 via the CN 106.

[0029] RAN 104 can communicate with CN 106, which can be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of WTRUs 102a, 102b, 102c, 102d. The data can have various quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. CN 106 can provide call control, billing services, mobile location-based services, prepaid calls, internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A, it will be understood that RAN 104 and / or CN 106 can communicate directly or indirectly with other RANs using the same RAT as RAN 104 or a different RAT. For example, in addition to being connected to RAN 104, which can utilize NR radio technology, CN 106 can also communicate with another RAN (not shown) using GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0030] CN106 may also function as a gateway for WTRU102a, 102b, 102c, 102d to access the PSTN108, the Internet 110, and / or other networks 112. The PSTN108 may include a circuit-switched telephone network that provides a plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices, where these networks and devices use a common communication protocol such as the transmission control protocol (TCP), the user datagram protocol (UDP), and / or the internet protocol (IP) of the TCP / IP internet protocol suite. The network 112 may include a wired communication network and / or a wireless communication network that is owned and / or operated by another service provider. For example, the network 112 may include another CN connected to one or more RANs that may use the same RAT as the RAN104 or a different RAT.

[0031] Some or all of the WTRU102a, 102b, 102c, 102d in the communication system 100 may include a multi-mode function (e.g., the WTRU102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example, the WTRU102c shown in Figure 1A may be configured to communicate with a base station 114a that may employ a cellular-based wireless technology and a base station 114b that may employ IEEE802 wireless technology.

[0032] Figure 1B is a system diagram illustrating an exemplary WTRU 102. As shown in Figure 1B, the WTRU 102 can 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, a non-removable memory 130, a removable memory 132, a power supply 134, a global positioning system (GPS) chipset 136, and / or other peripheral devices 138. It will be understood that the WTRU 102 can include any partial combination of the foregoing elements while remaining consistent with an embodiment.

[0033] The processor 118 can be a general-purpose processor, a dedicated 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), any other type of integrated circuit (IC), a state machine, etc. The processor 118 can perform signal coding, data processing, power control, input / output processing, and / or any other function that enables the WTRU 102 to operate in a wireless environment. The processor 118 can be coupled to a transceiver 120 that can be coupled to a transmit / receive element 122. Although Figure 1B illustrates the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 can be integrated together in an electronic package or chip.

[0034] The transmitting / receiving element 122 may be configured to transmit or receive signals to / from a base station (e.g., base station 114a) via the air interface 116. For example, in one embodiment, the transmitting / receiving element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmitting / receiving element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR signals, UV signals, or visible light signals. In yet another embodiment, the transmitting / receiving element 122 may be configured to transmit and / or receive both RF signals and optical signals. It will be understood that the transmitting / receiving element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0035] Although the transmitting / receiving element 122 is illustrated in FIG. 1B as a single element, the WTRU 102 may include any number of transmitting / receiving elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmitting / receiving elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via the air interface 116.

[0036] The transceiver 120 may be configured to modulate signals transmitted by the transmitting / receiving element 122 and demodulate signals received by the transmitting / receiving element 122. As described above, the WTRU 102 may have a multimode function. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs such as, for example, NR and IEEE 802.11.

[0037] The processor 118 of the WTRU 102 may be coupled to the speaker / microphone 124, keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit), and may receive data input by the user from these. The processor 118 may also output user data to the speaker / microphone 124, keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any suitable type of memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, etc. 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).

[0038] The processor 118 may receive power from the power supply 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for supplying power to the WTRU 102. For example, the power supply 134 may include one or more dry cells (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), a solar cell, a fuel cell, etc.

[0039] Processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current position of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) via the air interface 116 and / or may determine its location based on the timing of signals received from two or more neighboring base stations. It will be understood that the WTRU 102 may obtain location information by any suitable positioning method while remaining consistent with one embodiment.

[0040] Processor 118 may further be coupled to other peripheral devices 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connections. For example, the peripheral devices 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality / Augmented Reality (VR / AR) device, an activity tracker, etc. The peripheral devices 138 may include one or more sensors. The sensors may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, a humidity sensor, etc.

[0041] WTRU102 may include a full-duplex radio in which some or all of the transmissions and receptions of signals (associated with certain subframes for both UL (e.g., for transmission) and DL (e.g., for reception)) may be simultaneous and / or together. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference either via hardware (e.g., a choke) or via signal processing through a processor (e.g., a separate processor (not shown) or via processor 118). In one embodiment, WTRU102 may include a half-duplex radio for some or all of the transmissions and receptions of signals (associated with certain subframes for either UL (e.g., for transmission) or DL (e.g., for reception)).

[0042] FIG. 1C is a system diagram illustrating RAN104 and CN106 according to one embodiment. As described above, RAN104 may employ E-UTRA radio technology to communicate with WTRU102a, 102b, 102c via air interface 116. RAN104 may also communicate with CN106.

[0043] RAN104 may include eNodeBs 160a, 160b, 160c, although it will be understood that RAN104 may include any number of eNodeBs while maintaining consistency with one embodiment. Each of eNodeBs 160a, 160b, 160c may include one or more transceivers for communicating with WTRU102a, 102b, 102c via air interface 116. In one embodiment, eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, eNodeB 160a may, for example, transmit a wireless signal to WTRU102a and / or receive a wireless signal from WTRU102a using multiple antennas.

[0044] Each of the eNodeBs 160a, 160b, and 160c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, etc. As shown in FIG. 1C, the eNodeBs 160a, 160b, and 160c can communicate with each other via the X2 interface.

[0045] The CN 106 shown in FIG. 1C can include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although the foregoing elements are shown as part of the CN 106, it will be understood that any of these elements can be owned and / or operated by an entity other than the CN operator.

[0046] The MME 162 can be connected to each of the eNodeBs 162a, 162b, and 162c in the RAN 104 via the S1 interface and can function as a control node. For example, the MME 162 can play roles such as authenticating users of the WTRUs 102a, 102b, and 102c, activating / deactivating bearers, and selecting a specific serving gateway during the initial attach of the WTRUs 102a, 102b, and 102c. The MME 162 can provide control plane functions for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies such as GSM and / or WCDMA.

[0047] SGW164 can be connected to each of the eNodeBs 160a, 160b, and 160c in RAN104 via the S1 interface. SGW164 can generally route and transfer user data packets between the WTRUs 102a, 102b, and 102c. SGW164 can perform other functions such as the function of anchoring the user plane during handover between eNodeBs, the function of triggering paging when DL data is available to the WTRUs 102a, 102b, and 102c, and the function of managing and storing the contexts of the WTRUs 102a, 102b, and 102c.

[0048] SGW164 can be connected to PGW166, and PGW166 can provide access to a packet switched network such as the Internet 110 to the WTRUs 102a, 102b, and 102c to facilitate communication between the WTRUs 102a, 102b, and 102c and IP-enabled devices.

[0049] CN106 can facilitate communication with other networks. For example, CN106 can provide access to a circuit switched network such as PSTN108 to the WTRUs 102a, 102b, and 102c to facilitate communication between the WTRUs 102a, 102b, and 102c and conventional landline communication devices. For example, CN106 can include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that functions as an interface between CN106 and PSTN108. In addition, CN106 can provide access to another network 112 to the WTRUs 102a, 102b, and 102c, and this other network can include other wired and / or wireless networks owned and / or operated by other service providers.

[0050] The WTRU is described as a wireless terminal in FIGS. 1A - 1D, but in certain representative embodiments, it is contemplated that such a terminal can use a wired communication interface (e.g., temporarily or permanently) with a communication network.

[0051] In an exemplary embodiment, the other network 112 can be a WLAN.

[0052] A WLAN in infrastructure basic service set (BSS) mode can have an access point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP can have an access or interface to a distribution system (DS) or another type of wired / wireless network that carries traffic within and / or outside the BSS. Traffic to an STA originating from outside the BSS can reach the STA through the AP and be delivered to the STA. Traffic originating from an STA to a destination outside the BSS can be sent to the AP and then sent to their respective destinations. Traffic between STAs within the BSS can be sent, for example, through the AP, and the source STA can send the traffic to the AP, and the AP can deliver the traffic to the destination STA. Traffic between STAs within the BSS can be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be sent between the source STA and the destination STA (e.g., directly between them) using direct link setup (DLS). In certain exemplary embodiments, DLS can use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (e.g., all of the STAs) can communicate directly with each other. The IBSS mode of communication can be referred to herein as the "ad hoc" communication mode.

[0053] When using the 802.11ac infrastructure operation mode or a similar operation mode, the AP may transmit beacons on a fixed channel such as the primary channel. The primary channel may have a fixed width (e.g., a 20 MHz bandwidth) or a dynamically set width. The primary channel may be the operating channel of the BSS, but may be used by the STA to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. In the case of CSMA / CA, STAs including the AP (e.g., all STAs) may sense the primary channel. If the primary channel is detected / determined to be busy by a particular STA, the particular STA may back off. Only one STA (e.g., only one station) may transmit at any given time in a given BSS.

[0054] A High Throughput (HT) STA may use a 40 MHz wide channel for communication, and this 40 MHz wide channel may be formed, for example, through a combination of a primary 20 MHz channel and an adjacent or non - adjacent 20 MHz channel.

[0055] A Very High Throughput (VHT) STA may support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. A 40 MHz and / or 80 MHz channel may be formed by combining a plurality of consecutive 20 MHz channels. A 160 MHz channel may be formed by combining eight consecutive 20 MHz channels or by combining two non-consecutive 80 MHz channels, which may be referred to as an 80+80 configuration. In the case of the 80+80 configuration, after channel encoding, the data may pass through a segment parser that may divide the data into two streams. The Inverse Fast Fourier Transform (IFFT) process and the time domain process may be performed separately on each stream. The streams may be mapped to two 80 MHz channels, and the data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed, and the combined data may be transmitted to the Medium Access Control (MAC).

[0056] The sub-1 GHz operating mode is supported by 802.11af and 802.11ah. The channel operating bandwidth and carrier frequency are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports bandwidths of 5 MHz, 10 MHz, and 20 MHz in the TV White Space (TVWS) spectrum, and 802.11ah supports bandwidths of 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz using the non-TVWS spectrum. According to an exemplary embodiment, 802.11ah may support meter type control / machine type communications (MTC), such as MTC devices in a macro coverage area. The MTC device may have limited capabilities, including certain capabilities, for example, support for a certain and / or limited bandwidth (e.g., support only for these). The MTC device may include a battery having a battery life above a threshold (e.g., to maintain a very long battery life).

[0057] A WLAN system that supports multiple channels and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah includes 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 can be set and / or restricted by an STA from among all STAs operating in a BSS that supports a minimum bandwidth operation mode. In the example of 802.11ah, the primary channel can be 1 MHz wide for an STA (e.g., an MTC type device) that supports the 1 MHz mode (e.g., supports only this) even when the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operation modes. Carrier sensing and / or Network Allocation Vector (NAV) setting can depend on the status of the primary channel. For example, if the primary channel is busy by an STA transmitting to the AP (supporting only the 1 MHz operation mode), even if most of the available frequency band is idle, all of the available frequency band can be considered busy.

[0058] In the United States, the available frequency band that can be used by 802.11ah is 902 MHz to 928 MHz. In South Korea, the available frequency band is 917.5 MHz to 923.5 MHz. In Japan, the available frequency band is 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz depending on the country code.

[0059] FIG. 1D is a system diagram illustrating RAN 104 and CN 106 according to one embodiment. As described above, RAN 104 can communicate with WTRUs 102a, 102b, 102c via air interface 116 using NR radio technology. RAN 104 can also communicate with CN 106.

[0060] RAN104 may include gNBs 180a, 180b, and 180c, although it will be understood that RAN104 may include any number of gNBs while remaining consistent with one embodiment. Each of gNBs 180a, 180b, and 180c may include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, gNBs 180a, 180b, and 180c may implement MIMO technology. For example, gNBs 180a and 108b may utilize beamforming to transmit signals to and / or receive signals from gNBs 180a, 180b, and 180c. Thus, gNB 180a may transmit and / or receive radio signals to / from WTRU 102a, for example, using multiple antennas. In one embodiment, gNBs 180a, 180b, and 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 one embodiment, gNBs 180a, 180b, and 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).

[0061] WTRUs 102a, 102b, and 102c may communicate with gNBs 180a, 180b, and 180c using transmissions associated with scalable numerology. For example, the OFDM symbol interval and / or the OFDM sub-carrier interval may vary for different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRUs 102a, 102b, and 102c may communicate with gNBs 180a, 180b, and 180c using sub-frames or transmission time intervals (TTIs) of various or scalable lengths (e.g., including various numbers of OFDM symbols and / or varying lengths of absolute time durations).

[0062] gNBs 180a, 180b, and 180c may be configured to communicate with WTRUs 102a, 102b, and 102c in a stand-alone configuration and / or a non-stand-alone configuration. In a stand-alone configuration, WTRUs 102a, 102b, and 102c may communicate with gNBs 180a, 180b, and 180c without accessing other RANs (e.g., eNodeBs 160a, 160b, and 160c, etc.). In a stand-alone configuration, WTRUs 102a, 102b, and 102c may utilize one or more of gNBs 180a, 180b, and 180c as a mobility anchor point. In a stand-alone configuration, WTRUs 102a, 102b, and 102c may communicate with gNBs 180a, 180b, and 180c using signals in an unlicensed band. In a non-stand-alone configuration, WTRUs 102a, 102b, and 102c may communicate with and connect to gNBs 180a, 180b, and 180c while also communicating with and connecting to another RAN such as eNodeBs 160a, 160b, and 160c. For example, WTRUs 102a, 102b, and 102c may implement a DC principle for communicating with one or more gNBs 180a, 180b, and 180c and one or more eNodeBs 160a, 160b, and 160c substantially simultaneously. In a non-stand-alone configuration, eNodeBs 160a, 160b, and 160c may function as a mobility anchor for WTRUs 102a, 102b, and 102c, and gNBs 180a, 180b, and 180c may provide additional coverage and / or throughput for serving WTRUs 102a, 102b, and 102c.

[0063] Each of gNBs 180a, 180b, and 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decision-making, handover decision-making, user scheduling in UL and / or DL, support for network slicing, DC, interaction between NR and E-UTRA, routing of user plane data to user plane functions (UPFs) 184a, 184b, and routing of control plane information to access and mobility management functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D, gNBs 180a, 180b, and 180c can communicate with each other via the Xn interface.

[0064] CN 106 shown in FIG. 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and optionally data networks (DNs) 185a, 185b. Although the foregoing elements are shown as part of CN 106, it will be understood that any of these elements may be owned and / or operated by entities other than the CN operator.

[0065] AMF 182a and 182b can be connected to one or more of gNBs 180a, 180b, and 180c in RAN 104 via the N2 interface and can function as control nodes. For example, AMF 182a and 182b can perform roles such as user authentication of WTRUs 102a, 102b, and 102c, support for network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selection of specific SMFs 183a and 183b, management of the registration area, termination of non-access stratum (NAS) signaling, and mobility management. Network slicing can be used by AMF 182a and 182b to customize the CN support for WTRUs 102a, 102b, and 102c based on the type of service being utilized by WTRUs 102a, 102b, and 102c. For example, different network slices can be established for different use cases such as services that rely on ultra-reliable low latency (URLLC) access, services that rely on enhanced massive mobile broadband (eMBB) access, services for MTC access, etc. AMF 182a and 182b can provide control plane functions for switching between RAN 104 and other RANs (not shown) that employ other radio technologies such as non-3GPP (registered trademark) access technologies like LTE, LTE-A, LTE-A Pro, and / or WiFi.

[0066] SMF183a and 183b can be connected to AMF182a and 182b in CN106 via the N11 interface. SMF183a and 183b can also be connected to UPF184a and 184b in CN106 via the N4 interface. SMF183a and 183b can select and control UPF184a and 184b and configure the routing of traffic passing through UPF184a and 184b. SMF183a and 183b can perform other functions such as the function of managing and allocating UE IP addresses, the function of managing PDU sessions, the function of implementing policies and controlling QoS, and the function of providing DL data notifications. The PDU session type can be IP-based, non-IP-based, Ethernet-based, etc.

[0067] UPF184a and 184b can be connected to one or more of gNB180a, 180b, and 180c in RAN104 via the N3 interface, thereby providing WTRU102a, 102b, and 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, and 102c and IP-compatible devices. UPF184 and 184b can perform other functions such as packet routing and forwarding, user plane policy implementation, support for multi-home PDU sessions, user plane QoS processing, DL packet buffering, and providing mobility anchoring.

[0068] CN106 can facilitate communication with other networks. For example, CN106 can include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that functions as an interface between CN106 and the PSTN 108. In addition, CN106 can provide the WTRUs 102a, 102b, 102c with access to another network 112, which can include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c can be connected to the local DNs 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0069] In view of FIGS. 1A-1D and the corresponding descriptions of FIGS. 1A-1D, one or more of the functions described herein with respect to one or more of the WTRUs 102a-102d, base stations 114a-114b, eNodeBs 160a-160c, MME 162, SGW 164, PGW 166, gNBs 180a-180c, AMFs 182a-182b, UPFs 184a-184b, SMFs 183a-183b, DNs 185a-185b, and / or any other device described herein can be performed by one or more emulation devices (not shown). An emulation device can be one or more devices configured to emulate one or more of the functions described herein. For example, an emulation device can be used to test other devices and / or to simulate network and / or WTRU functionality.

[0070] An emulation device can be designed to implement one or more tests of other devices in a laboratory environment and / or an enterprise network environment. For example, one or more emulation devices may perform one or more or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. One or more emulation devices may perform one or more or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. An emulation device can be directly coupled to another device for the purpose of testing and / or performing tests using over-the-air wireless communication.

[0071] One or more emulation devices may perform one or more functions including all while not being implemented / deployed as part of a wired and / or wireless communication network. For example, an emulation device can be utilized in a test scenario in a test laboratory and / or in a wired and / or wireless communication network that is not deployed (e.g., for testing) to implement tests of one or more components. One or more emulation devices can be test equipment. Direct RF coupling and / or wireless communication via an RF circuit (which may include one or more antennas) can be used by an emulation device to transmit and / or receive data.

[0072] In a wireless system (e.g., 5G New Radio (NR)), a WTRU can monitor downlink radio link quality based on reference signals configured as radio link monitoring reference signal (RLM-RS) resources (plural) to detect the downlink radio link quality of a primary cell (PCell) as well as primary and secondary cells (PSCell). The configured RLM-RS resources can be all synchronization signal blocks (SSBs), all channel state information reference signals (CSI-RSs), or a mixture of SSBs and CSI-RSs. The WTRU may not need to perform RLM outside of an active downlink bandwidth part (DL BWP). Similarly, the WTRU can evaluate the downlink radio link quality of a serving cell to detect beam blockage.

[0073] One way to save power can include the WTRU relaxing RLM / BFD requirements. There can be one or more criteria for RLM / BFD relaxation that can address one or more cases. For example, there can be SSB-based RLM / BFD measurement relaxation in frequency range 1 (FR1). For example, there can be CSI-RS-based RLM / BFD measurement relaxation in FR1. For example, there can be CSI-RS-based RLM / BFD measurement relaxation in frequency range 2 (FR2). For example, there can be SSB-based RLM / BFD measurement relaxation in FR2.

[0074] The relaxed BFD / RLM requirements can be supported for all deployment scenarios such as new radio stand-alone (NR SA), E-UTRA-NR dual connectivity (EN-DC), NR-E-UTRA dual connectivity (NE-DC), intra-band carrier aggregation (CA) in NR, inter-band CA in NR, and new radio dual connectivity (NR-DC).

[0075] Regarding relaxation criteria, one or more of the following factors may be applied and / or considered. For example, the relaxation criteria may consider the network to enable and disable measurement relaxation. In an example, whether relaxed RLM / BFD requirements may be applied may depend on both serving cell quality and WTRU mobility state. In an example, the measurement relaxation criteria may be based on channel quality and / or mobility. In an example, the relaxation criteria may also consider that when the WTRU meets any of the serving cell quality end condition(s), low mobility end condition(s), and / or DRX cycle length, it is not permitted for relaxation and the WTRU can terminate the relaxation mode. The WTRU can perform measurements over a period of time when not in a relaxed state and then perform additional measurements after entering the relaxed state. In an example, when the WTRU applies a DRX cycle longer than 80 ms, it may be assumed that the WTRU does not perform relaxed RLM / BFD measurements and the existing RLM / BFD requirements may be applied. In an example, when neither the serving cell quality criteria nor the low mobility criteria are configured, the existing RLM / BFD requirements may be applied. In an example, in the case of dedicated or broadcast signaling to indicate to the WTRU that it can relax RLM / BFD measurements, one or more of the previous list(s) may be modified. In some examples, when good serving cell criteria are predefined, one or more of the previous list(s) may be modified.

[0076] The WTRU can determine to enter a measurement relaxation state based on the power measurement value (e.g., RSRP) exceeding a power threshold (e.g., exceeding the power threshold indicates high channel quality). The power threshold can include one or more of a SINR threshold, an RSRP threshold, an RSSI threshold, or an RSRQ threshold. Additionally and alternatively, the WTRU can determine to enter a measurement relaxation state based on the variation of the power measurement value (e.g., RSRP variation) being below a variation / mobility threshold (e.g., being below the variation threshold indicates low mobility of the WTRU). The variation / mobility threshold can include the change in RSRP and / or the cell change count within a specific time limit. The WTRU can determine to exit the measurement relaxation state based on the power measurement value (e.g., RSRP) being below the power threshold and / or based on the variation of the power measurement value being above the variation / mobility threshold. In the case of low mobility criteria, one or more of the following may be applied and / or considered (e.g., L3 reference signal received power (RSRP) measurement variation and / or related RS measurements for L3 RSRP measurement).

[0077] Regarding cell quality criteria, one or more of the following may be applied and / or considered: The good serving cell quality criteria for RLM / BFD relaxation can be defined when the radio link quality is better than a threshold (e.g., the radio link quality in the good serving cell quality criteria for RLM / BFD relaxation can be based on the signal-to-interference-plus-noise ratio (SINR)). In an example, the WTRU can reuse the SINR for RLM / BFD evaluation when determining whether the serving cell quality criteria are met. The WTRU can use a pre-defined or configured threshold. The SINR definition for good serving cell quality can have one or more of its own criteria.

[0078] The RLM / BFD relaxation criteria can be configured by dedicated signaling (e.g., RadioLinkMonitoringConfig) as a baseline when parameters are used instead of pre-defined and / or implementation-specific scenarios. The access stratum (AS) capabilities procedure can be used to report the WTRU capabilities that support RLM / BFD relaxation. The presence and / or absence of a configuration for the RLM / BFD relaxation criteria in the signaling can indicate to the WTRU whether and / or if it should evaluate the criteria.

[0079] In an example, an issue may arise regarding whether the network (NW) needs to control when the WTRU enters the relaxed state. In one example, radio resource control (RRC) signaling can be used to report and activate the relaxed state. However, this approach may create an undesirable overhead for dynamic activation / deactivation whenever the criteria are met.

[0080] In an example, media access control - control element (MAC CE) and / or L1 signaling can be used (e.g., by the NW) to dynamically activate / deactivate RLM / BFD relaxation. The WTRU can be configured to receive signaling that enables the WTRU to send a report. For example, the MAC CE and / or L1 signaling can be used by the WTRU to send a report related to RLM / BFD relaxation to the NW, such as a report that includes an indication of whether, for example, the relaxation criteria are met.

[0081] Figure 2 shows an exemplary signaling message sequence 200. The WTRU 202 transmits its RRC radio access capabilities to the gNB 204 at 206. At 208, the gNB 204 can configure the reporting criteria using RRC signaling. At 210, if the criteria are met, the WTRU 202 can send an indication to the gNB 204. At 212, upon receiving an indication that the criteria are met, the gNB 204 can activate RLM / BFD relaxation.

[0082] Regarding the relaxation / reporting criteria, in an example, the out-of-synchronization and synchronization block error rate (BLER) used for physical downlink control channel (PDCCH) mapping can be as shown in Table 1.

[0083] [Table 1]

[0084] In this example, the ratio between the PDCCH resource element (RE) energy and the average secondary synchronization signal (SSS) RE energy is 4 dB and 0 dB for out-of-synchronization (OOS) and in-synchronization (IS), respectively. Thus, a difference of 5 dB can be defined.

[0085] Radio link monitoring can have specific evaluation periods for non-DRX and DRX case T Evaluate_out_SSB and T Evaluate_in_SSB for FR1 and FR2, respectively. In an example, the evaluation period based on the SSB can also be defined on the CSI-RS. Thus, in the following examples, the SSB criteria can be used without loss of generality.

[0086] In an example, the evaluation periods for OOS and IS can be evaluated as seen in Table 2. The example seen in Table 2 further considers FR1, and similar requirements may be applicable to the CSI-RS.

[0087] [Table 2]

[0088] As can be seen in Table 2, P is a coefficient that takes into account gaps that overlap and / or do not overlap with SSB-related symbols and can take different values.

[0089] In the example, to perform RLM relaxation, the WTRU can determine the requirements (e.g., the evaluation period) using a first DRX cycle value, and the DRX cycle value used can be different from the value of the actual DRX cycle. For example, a scaling method can be used where the first DRX cycle value can be determined by scaling the actual DRX cycle value (e.g., by an integer). The scaling factor K can be signaled by the network in the RRC configuration. In the example, the scaling factor K can be signaled within the activation message. When the WTRU does not have a configured DRX cycle, the relaxation method for relaxation measurement and the first relaxation virtual DRX cycle can be semi-statically configured by the network in the RRC configuration. Further, the first relaxation virtual DRX cycle can be separately and dynamically activated by the MAC or DCI using the PDCCH via the activation message.

[0090] In the example, the requirements can be directly scaled. For example, the evaluation period and / or the indication interval can be scaled by a scaling factor. Different requirements can be scaled by different scaling factors. The scaling factor(s) can be signaled by the network in the RRC configuration. The scaling factor(s) can be signaled within the activation message.

[0091] In an example, the WTRU can use the value of the virtual DRX cycle while calculating RLM / BFD requirements, such as the evaluation period and / or the indication interval. The value of the virtual DRX cycle can be different from (e.g., larger than) the actual DRX cycle. The virtual DRX cycle can be used when the actual DRX is not configured. A possible set of values of the virtual DRX cycle can be configured by a base station (e.g., gNB). The specific value to be used may be indicated by the base station in an activation message and / or autonomously selected by the WTRU. For example, when signaled to enter a relaxed state, the WTRU can select one of the configured virtual DRX cycle values. This selection can be the first evaluation period that can be the lowest in the set of signaled values. The WTRU can then increment the value (e.g., by selecting a larger configured value) progressively.

[0092] Additionally and / or alternatively, the WTRU can follow a base station command, such as UP or DOWN, while changing the virtual DRX cycle for RLM evaluation. The base station can send an UP or DOWN command according to the reported cell / beam measurement values, provided that the WTRU can be within relaxed criteria conditions. For example, if the WTRU is configured to be at the minimum configurable virtual DRX cycle and receives a DOWN command, the WTRU can end the RLM relaxed operation mode. If the WTRU receives an UP command following better cell / beam reporting (e.g., a report indicating a higher beam RSRP than the previous report), the WTRU can move to a subsequent virtual DRX cycle in the configured list using more relaxed measurement sampling for RLM.

[0093] The relaxation criteria for RLM can be a threshold defined as an offset to the OOS and / or IS SINR mapping. This can be, for example, a Y = 2dB offset to the IS-related SINR mapping for good quality of the serving cell. This offset may be predefined and / or may be a network configurable parameter. This offset can be uniquely defined for the OOS or IS SINR mapping and / or can be set or configured individually for each OOS and / or IS value. The RLM relaxation mode trigger can be based on a measurement that reaches and remains above this threshold over a certain amount of time. This time can be defined, for example, semi-statically configured by the network. This time can also be predefined.

[0094] If the WTRU meets the low mobility conditions based on RSRP cell measurement variations and good cell quality regarding RLM over a certain time interval, the WTRU can report this preferred state of RLM / BFD relaxation to the network.

[0095] In an example, in addition to the serving cell criteria and the low mobility criteria, the relaxation criteria can include, for example, beam switching and / or trigger time (TTT). The beam change count can be detected in the WTRU or the NW. For example, in the WTRU, the beam(s) used for RSRP need to remain within a predefined time interval t. The WTRU can report that the TTT criteria are met over a certain duration before triggering a report.

[0096] The relaxation criteria and the reporting criteria can be separate. For example, the reporting criteria can use a lower threshold than the relaxation criteria. In an example, the WTRU can report an indication that the reporting criteria are met. Upon receiving the report, the NW can activate the relaxation. Then, the WTRU can apply the actual relaxation when the relaxation criteria are met. DL control information can be received and the control information can have an activation instruction.

[0097] For OOS and IS in the non-DRX case, the L1 (physical layer) indication interval is such that T( Indication_interval ) is configured to be max(10 ms, T RLM-RS,M ), where T RLM,M is the shortest periodicity of all configured RLM-RS resources for the cell being monitored.

[0098] For OOS and IS in the DRX case, the L1 (physical layer) indication interval is such that when the DRX cycle_length is 320 ms or less, T Indication_interval is Max(10 ms, 1.5 × DRX_cycle_length, 1.5 × T RLM-RS,M ), and when the DRX cycle_length exceeds 320 ms, T Indication_interval is configured to be DRX_cycle_length .

[0099] When the network activates the relaxed state, the WTRU can scale T Indication_interval according to the measurement sampling rate after applying the relaxation factor K. The relaxation factor K may be configured semi-statically by the network or alternatively may be indicated by the network in the relaxed state activation.

[0100] For example, one way to scale T Indication_interval may be to use a virtual DRX relaxation cycle length. The virtual DRX relaxation cycle length may be defined as the sample measurement periodicity in the relaxed state. In this case, T Indication_interval can be defined as follows: T Indication_interval : max(10 ms, virtual DRX relaxation cycle length, T RLM-RS、M ).

[0101] In an example, T Indication_interval can be defined as follows: T Indication_interval : max(10 ms, R * T RLM-RS,M) R is a scaling factor. When the scaling coefficient R is not an integer value, the scaling coefficient R can be rounded up, for example, by performing a ceiling operation such as ceil(R). The scaling coefficient R does not have to be an integer value when it is used to scale other measurement values or thresholds for RLM Qin, Qout. The scaling coefficient R is also T evaluate It may be related to a virtual DRX relaxation cycle length that can link measurement opportunities for a period. For example, the virtual DRX relaxation cycle length can be R*T RLM-RS,M and can be defined as such.

[0102] A WTRU capable of RLM / BFD relaxation features can be configured using one or more parameters. For example, the WTRU can be configured with one or more parameters for relaxation via RRC signaling. The WTRU can receive a MAC CE that can configure the parameters, for example, by indicating a value from a set of predefined values. These predefined values can include, for example, a relative threshold Y for an IS-mapped threshold for good quality of the serving cell, a TTT for signaling the RLM / BFD relaxation readiness status to the network, a counter for an IS over good quality offset threshold that can be reset each time the WTRU samples a measurement below an offset level, and / or a TTT for signaling to the network from the RLM / BFD relaxation state when the WTRU samples a measurement where OOS is detected.

[0103] Additionally and / or alternatively, sampled measurements and / or a defined number of samples below the IS normal operation threshold mapping can signal the relaxation state. Additionally and / or alternatively, a prohibit timer can prevent the WTRU from signaling an RLM / BFD relaxation readiness complete state after signaling outside the RLM / BFD relaxation state. A prohibit timer that can track a prohibit time period can be included with configuration information. The configuration information can also indicate one or more prohibit time periods.

[0104] The relaxed state characteristics may be accompanied by an uplink report that can be approached in one or more ways. For example, the UL report may be reported in the MAC CE, and / or in the uplink control information (e.g., in the PUCCH and / or PUSCH), in the scheduling request, and / or in the buffer status report. The UL report may include a single bit to indicate that a criterion (e.g., SINR threshold and / or low mobility criterion) is met. The base station can configure the reporting criterion. The UL report may include multiple bits (e.g., 2 bits to separately indicate the criteria). For example, one bit may indicate that the SINR threshold is met, and / or one bit may indicate that the low mobility criterion is met. The UL report may include two or more bits to request an increase or decrease in the level of relaxation. For example, the bits may indicate an increase and / or decrease in the virtual DRX cycle value used for the RLM / BFD requirements in the relaxed state. For example, the bits may indicate an indication of the value of the virtual DRX cycle used for the RLM / BFD requirements in the relaxed state.

[0105] In an example, the bits may be used to increase and / or decrease the threshold and / or select the threshold from a set of thresholds. What the report indicates (e.g., the meaning of the code point included in the report) may depend on whether the NW has enabled and / or disabled relaxation. For example, if the NW has disabled relaxation, the report may indicate whether the threshold and the low mobility criterion are met. If the NW has enabled relaxation, the report may indicate whether the threshold and the low mobility criterion are no longer met. Further, if the NW has enabled relaxation, the bits may be set according to different thresholds or may indicate an increase / decrease in the threshold).

[0106] Regarding dual connectivity carrier aggregation (DCCA), reporting and / or activation can be performed separately for each serving cell and / or for each serving beam. Additionally and / or alternatively, regarding DCCA, the WTRU can report the results to either the master cell group (MCG) and / or the secondary cell group (SCG). This may also mean enabling / disabling multiple bits. Further, reporting separately for each carrier may imply multiple bits for reporting.

[0107] In an example, a prohibit timer can be applied to a reporting trigger. For example, the WTRU can be configured to start a prohibit time period when the WTRU transmits a report (e.g., a report to either the MCG and / or the SCG). After the WTRU finishes relaxation, the timer can start, and the WTRU can be prohibited from requesting relaxation via an UL report and / or entering relaxation while the timer is running. Additionally and / or alternatively, the WTRU may be prohibited from changing the relaxation state while the timer is running. The UL report can include whether the WTRU is in a relaxed state. The UL report can include an indication of whether any OOS indication was detected during the relaxed state. The UL report can include an indication of whether a fallback and / or an existing relaxed state occurred (e.g., whether the WTRU is currently relaxed and whether the criteria are met). A new RRC re - establishment cause value can be introduced to explicitly indicate a radio link failure (RLF) during relaxation (e.g., serving cell and / or neighbor cell measurements, location information, and other information related to supporting self - organizing networks and / or minimizing drive tests).

[0108] In the case of DL control, when the WTRU reports the RLM / BFD relaxation preparation completion state to the network, the WTRU can receive an activation command. The activation command can simply activate the relaxation configuration that has already been received by the WTRU through the RRC configuration. Activation can mean, for example, that the WTRU can start the implementation of RLM / BFD in the relaxed state. Additionally and alternatively, the network can indicate in the activation command the value of the relaxation coefficient K and / or the value of the virtual DRX cycle that the WTRU can use. The relaxation coefficient K and / or the virtual DRX cycle value can be applied to the current evaluation period rule, and the current evaluation period rule can affect the TE valvate_out value and the TE valvate_in value.

[0109] DL control information can use a single bit to permit and / or disallow relaxation based on the NW knowledge of the deployment. For example, DL may be configured to indicate only "activation". In that example, the WTRU can autonomously indicate "deactivation" when the criteria are no longer met and / or when an "end" criterion is met (e.g., the "end" criterion specifies when the WTRU is expected to end the relaxed state).

[0110] DL control information can indicate multiple relaxation requirements. For example, different requirements are needed to meet the SINR threshold and / or the low mobility criterion. The use of multiple bits can indicate these different requirements. In the example, gradual relaxation may be implemented (e.g., the DL control information can indicate how much relaxation is possible). DL control information can indicate which requirements apply (e.g., whether it is used with the up and / or down requests from the WTRU and / or whether to increment and / or decrement the relaxation coefficient K value).

[0111] In the case of DL control, the WTRU can relax if the NW indicates that it is "permitted" and the criteria are met. In this case, different threshold(s) may exist for applying reporting and / or relaxation. These different thresholds can be achieved by applying an offset to a configured and / or predefined criterion and / or by signaling a separate threshold. Additionally and / or alternatively, the use of a separate threshold can enable reporting to be done before the criterion that enables the WTRU to relax. In this case, the use of a separate threshold can advantageously compensate for processing delays at the gNB and / or propagation delays in the case of a non-terrestrial network (NTN).

[0112] DL control can have an additional state where the NW indicates "permission" even if the criteria are not met and / or not reported. The NW can base this additional state, for example, on low mobility detected in the network. The indication can be more accurate than cell quality measurements by the WTRU in the case of beam switching.

[0113] In the case of RLF, a WTRU (e.g., an NR WTRU) can use counters and / or timers such as counters N310, N311, and timer T310 to determine when to declare RLF. For example, when the physical layer detects N310 consecutive OOS indications, the WTRU can start a timer (e.g., T310). While T310 is running, the WTRU can attempt to resynchronize to the current cell. For example, if the physical layer transmits N311 consecutive IS indications, the WTRU can stop T310 and consider itself to have returned to IS. If T310 expires before the physical layer transmits N311 IS indications, the WTRU can consider that RLF has occurred. Further, T310 can trigger the RRC reestablishment procedure.

[0114] While implementing RLM using relaxed requirements, the WTRU can have its OOS and IS indication periods scaled accordingly, and thus RLF detection may take longer. To address this situation and avoid network and / or WTRU performance issues, T310 can be scaled. For example, T310 can be scaled according to the same scaling factor for DRX and / or indication to accommodate the same number (e.g., the T310 timer) of IS indications within the timer period T311. Additionally and alternatively, the T310 timer can be maintained at the same value and / or the N310 counter can be scaled down to conform to OOS indications within the same amount of time, using regular or relaxed requirements. The RLF condition can scale the N311 counter such that the number of IS indications required to meet the "RLF recovery" condition is the same during the same T310, regardless of whether relaxed monitoring requirements or normal monitoring requirements are used.

[0115] Additionally and alternatively, a WTRU that meets the RLF condition while using relaxed requirements can avoid declaring RLF at this point. Instead, such a WTRU can autonomously fallback to the normal operating mode for RLM and / or restart the RLM timer and counter, and then the WTRU can declare RLF only when the normal operating conditions for RLF are met.

[0116] Although specific counters and / or timers are referenced herein, these references are intended for illustrative purposes only and the relevant methods and / or techniques can generally be applied to any counter and / or timer.

[0117] In the case of fallback related to relaxation features, in addition to signaling from the RLM / BFD relaxation readiness state and / or the RLM / BFD relaxation state, the WTRU can automatically fallback to normal RLM / BFD procedures based on one or more conditions. These conditions include, for example, the network configuring new measurements, the network configuring new measurements with gaps, cell activation and / or deactivation within the same cell group, and / or bandwidth part activation or change, the WTRU receiving a new RLM / BFD relaxation configuration and potentially having to resume procedures to enter the relaxation readiness state when receiving the new RLM / BFD configuration, the WTRU detecting one or more OOS indications, and / or the WTRU detecting that the conditions of the RLM / BFD relaxation state are no longer met, and / or detecting an end condition and falling back to normal RLM / BFD operation. Additionally and alternatively, separate criteria may be used for entering and exiting the relaxation state, for example, the relaxation state is activated when thresholds and hysteresis are met, and exits the relaxation state when below the threshold and / or without hysteresis. Additionally and alternatively, separate criteria such as TTT can be applied for entering relaxation or reporting criteria, but termination and / or fallback occur instantaneously.

[0118] Figure 3 shows an exemplary flowchart 300 illustrating a method for a relaxation operation. At 302, the WTRU may be configured by RRC signaling to enable reporting of RLM / BFD relaxation. The configuration may include an SINR threshold for determining serving cell quality and / or an indication of a relative RSRP threshold and time period for determining low mobility. At 304, the reporting criteria may be initialized and / or updated to include serving cell quality and / or low mobility based on the configuration and a predetermined rule(s). At 306, the WTRU may continuously and / or periodically evaluate the reporting criteria until one or more of the reporting criteria are met. At 308, the WTRU may transmit an uplink indication (e.g., in a MAC CE) as to whether one or more criteria are met. At 310, the WTRU may receive a downlink indication (e.g., in a MAC CE) as to whether and / or how the WTRU may relax its RLM / BFD requirements. At 312, the WTRU may determine whether a relaxation criterion is met. This may include the value of the DL indication and / or an indication as to whether other criteria (e.g., serving cell quality and / or low mobility) are met. At 314, the WTRU may update the measurement requirements in use. Then, at 314, the WTRU may proceed to update the reporting criteria based on the configuration and / or measurement requirements in use.

[0119] As described herein, the upper layer may refer to one or more layers in the protocol stack and / or a particular sublayer within the protocol stack. The protocol stack may be composed of one or more layers within a WTRU and / or a network node (e.g., eNB, gNB, other functional entities, etc.), where each layer may have one or more sublayers. Each layer and / or sublayer may perform one or more functions. Each layer and / or sublayer may communicate directly and / or indirectly with one or more of the other layers and / or sublayers. In an example, these layers and / or sublayers may be numbered, such as, for example, Layer 1, Layer 2, and Layer 3. For example, Layer 3 may comprise one or more of, for example, NAS, IP, and / or RRC. For example, Layer 2 may be composed of one or more of the following. That is, they may be packet data convergence protocol (PDCP), RLC, and / or MAC. For example, Layer 3 may be composed of physical (PHY) layer type operations. The higher the layer number, the more upper the layer is relative to the other layers (e.g., Layer 3 is higher than Layer 1).

[0120] In an example, the foregoing example may be referred to as the layer and / or sublayer itself, regardless of the layer number, and may be referred to as the upper layer as described herein. For example, the upper layer may refer to one or more of the following layers / sublayers, from the topmost to the bottommost, such as the NAS layer, the RRC layer, the PDCP layer, the RLC layer, the MAC layer, and / or the PHY layer. Any reference herein to the upper layer associated with a process, device, or system may refer to a layer that is higher than the layer of the process, device, or system. In an example, a reference herein to the upper layer may refer to a function or operation performed by one or more of the layers described herein. In an example, a reference herein to the upper layer may refer to information transmitted and / or received by one or more of the layers described herein. In an example, a reference herein to the upper layer may refer to a configuration transmitted and / or received by one or more of the layers described herein.

[0121] Figure 4 shows an exemplary flowchart illustrating a procedure 400 that may be performed by a WTRU to determine measurements based on relaxation criteria, when to enter (or exit) a relaxed state, and how to report to the network and / or cell when entering (or exiting) the relaxed state. At step 402, the WTRU may receive configuration information. The configuration information may include any combination of measurement relaxation criteria (e.g., a first set of relaxation criteria) for RLM or BDF, an indication that reporting to the cell is enabled, and / or a prohibited time period. After receiving the configuration information, the WTRU may, at 404, perform measurements based on (e.g., using) the first set of relaxation criteria (e.g., a first evaluation period and / or a first periodicity). The measurements may include L3 RSRP measurement variations and / or associated RS measurements for L3 RSRP measurements.

[0122] At 406, the WTRU can compare the measurement value with one or more threshold values. The threshold values can include one or more of a power threshold value and / or a mobility threshold value (e.g., a SINR threshold value, an RSRP threshold value, an RSSI threshold value, an RSRQ threshold value, and / or a low mobility criterion such as a change in RSRP within a specific time limit and / or a cell change count, etc.).

[0123] At 408, the WTRU can select a set of relaxation criteria (e.g., a first set of relaxation criteria or a second set of relaxation criteria) based on a comparison between the measurement value taken using a first set of relaxation criteria and one or more threshold values. For example, if the measurement value exceeds one or more threshold values, the WTRU can select the first set of relaxation criteria, and if the measurement value is below one or more threshold values, the WTRU can select the second set of relaxation criteria. The second relaxation criteria can include a second evaluation period and / or a second periodicity (e.g., which can be different from the first evaluation period and / or the first periodicity). In some examples, the WTRU can use the first relaxation criteria when the WTRU is not in a measurement relaxation state, and can use the second relaxation criteria when the WTRU is in a measurement relaxation state, or vice versa.

[0124] At 410, the WTRU can perform measurements based on the set of relaxation criteria selected at 408. At 412, the WTRU can compare the measurements performed at 410 with one or more threshold values to determine, for example, whether a change in the relaxation state has occurred (e.g., such that the WTRU can determine whether to change to a measurement relaxation state or change from a measurement relaxation state). The WTRU can use different relaxation criteria when in a measurement relaxation state compared to when the WTRU is not in a measurement relaxation state. At 414, the WTRU can determine, for example, based on the comparison performed at 412, whether the WTRU has changed the relaxation state. If the WTRU determines that the relaxation state has not changed, the WTRU can return to 410 and compare the measurement value taken using the selected set of relaxation criteria with one or more threshold values.

[0125] When the WTRU determines that the relaxation state has changed, the WTRU can determine, at 416, whether the prohibition time period has expired (e.g., whether the prohibition timer is running). As described in more detail herein, the WTRU can be configured to start a prohibition timer at 402 based on the prohibition time period received in the configuration information. For example, the WTRU may be configured to start a prohibition timer in response to sending a report (e.g., a UL report) indicating the WTRU's measurement relaxation state (e.g., whether the WTRU has entered or exited the measurement relaxation state) to the network, which may be done, for example, at 418. If at 416 the WTRU determines that the prohibition time period has not expired, the WTRU returns to 410 and can compare the measurement values taken using the selected set of relaxation criteria to one or more thresholds.

[0126] If the WTRU determines that the prohibition time period has expired, the WTRU can send a report to the network at 418 indicating that it has entered (or exited) the relaxation state. For example, if the WTRU determines that the prohibition time period has expired, the WTRU can change its measurement relaxation state. In some examples, the WTRU can report a measurement relaxation state indication when the relaxation state changes, when the status report is enabled, and / or when the prohibition timer is not running. By notifying the network and / or cell when the WTRU enters and / or exits the relaxation state, the network and / or cell can know when the conditions are optimal and / or when the WTRU can react quickly or slowly.

[0127] At 420, after the WTRU transmits a report, the WTRU can resume the prohibition timer. In an example, the WTRU can start a prohibition time period when the WTRU transmits a report (e.g., a UL report). In some examples, the WTRU can select a set of relaxation criteria for performing measurements (e.g., a first set of relaxation criteria when the WTRU is not in a relaxed state, or a second set of relaxation criteria when the WTRU is in a relaxed state), and then return to 410. The use of the prohibition time period can, for example, prevent the WTRU from entering and exiting the relaxed state too frequently and / or reduce the number of reports (e.g., UL reports) that the WTRU transmits to the network.

[0128] Features and elements are described above in specific combinations, but those skilled in the art will understand that each feature or element can be used alone or in any combination with other features and elements. Additionally, the methods described herein can be implemented in a computer program, software, or firmware incorporated into a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, magnetic media such as read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, internal hard disks, and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A radio frequency transceiver for use in a WTRU, terminal, base station, RNC, or any host computer can be implemented using a processor associated with the software.

Claims

1. 1. A wireless transmit / receive unit (WTRU) comprising a processor and a memory, The processor and the memory receiving configuration information indicating a measurement relaxation criterion for measurements associated with radio link monitoring (RLM) or beam failure detection (BFD) and a value of a prohibition timer associated with reporting a measurement relaxation state; determining, based on the measurement relaxation criterion, that the WTRU should operate in a measurement relaxation state; transmitting a first report indicating that the WTRU is operating in the measurement relaxation state and starting the prohibit timer based on a determination that the WTRU should operate in a measurement relaxation state; determining that the measurement relaxation state of the WTRU has changed based on the measurement relaxation criteria; determining that the inhibit timer is not running; transmitting a second report based on the determination that the measurement relaxation state has changed and the determination that the prohibit timer is not running, the second report including an indication of the changed measurement relaxation state; and starting the inhibit timer based on a determination that the WTRU should operate in the changed measurement mitigation state; A WTRU configured to perform the following:

2. 2. The WTRU of claim 1, wherein the first report and the second report each include a respective indication of a measurement mitigation state for each of a plurality of serving cells.

3. 2. The WTRU of claim 1, wherein the configuration information is received in a first radio resource control (RRC) message, the first report is sent in a second RRC message, and the second report is sent in a third RRC message.

4. The WTRU of claim 1 , wherein the measurement relaxation state is associated with a measurement evaluation period that is longer than a measurement evaluation period of the changed measurement relaxation state.

5. 2. The WTRU of claim 1, wherein the first report and the second report each include a respective indication of whether an out-of-sync (OOS) indication was detected during the measurement relaxation state.

6. 10. The WTRU of claim 1, wherein the processor and the memory are further configured to determine to enter the measurement relaxation state based on a reference signal received power (RSRP) value exceeding a threshold.

7. The WTRU of claim 1 , wherein the processor and the memory are further configured to perform measurements based on the measurement relaxation criteria.

8. 8. The WTRU of claim 7, wherein the measurements include an L3 Reference Signal Received Power (RSRP) measurement variation or an associated Reference Signal (RS) measurement for an L3 RSRP measurement.

9. The processor and the memory performing a measurement based on said measurement relaxation criteria; comparing the measurement to one or more thresholds, the one or more thresholds including a signal to interference ratio (SINR) threshold, a reference signal received power (RSRP) threshold, a received signal strength indicator (RSSI) threshold, a reference signal received quality (RSRQ) threshold, and / or a change in RSRP within a certain time limit, and / or a low mobility criterion such as a cell change count; determining whether the WTRU has changed a measurement mitigation state based on the comparison; and The WTRU of claim 7 further configured to perform:

10. The processor and the memory receiving a first activation command indicating that the WTRU may start performing radio link monitoring (RLM) or beam failure detection (BFD) after transmitting the first report; receiving a second activation command indicating that the WTRU may start performing radio link monitoring (RLM) or beam failure detection (BFD) after transmitting the second report; The WTRU of claim 1 further configured to perform:

11. 1. A method performed by a wireless transmit / receive unit (WTRU), comprising: receiving configuration information indicating a measurement relaxation criterion for measurements associated with radio link monitoring (RLM) or beam failure detection (BFD) and a value of a prohibition timer associated with reporting a measurement relaxation state; determining, based on the measurement relaxation criterion, that the WTRU should operate in a measurement relaxation state; transmitting a first report indicating that the WTRU is operating in the measurement relaxation state and starting the prohibit timer based on a determination that the WTRU should operate in a measurement relaxation state; determining that the measurement relaxation state of the WTRU has changed based on the measurement relaxation criteria; determining that the inhibit timer is not running; transmitting a second report based on the determination that the measurement relaxation state has changed and the determination that the prohibit timer is not running, the second report including an indication of the changed measurement relaxation state; and starting the inhibit timer based on a determination that the WTRU should operate in the changed measurement mitigation state; The method includes:

12. 12. The method of claim 11, wherein the first report and the second report each include a respective indication of a measurement mitigation state for each of a plurality of serving cells.

13. 12. The method of claim 11, wherein the configuration information is received in a first radio resource control (RRC) message, the first report is sent in a second RRC message, and the second report is sent in a third RRC message.

14. The method of claim 11 , wherein the measured relaxation state is associated with a measurement evaluation period that is longer than a measurement evaluation period of the changed measured relaxation state.

15. 12. The method of claim 11, wherein the first report and the second report each include a respective indication of whether an out-of-sync (OOS) indication was detected during the measurement relaxation state.

16. The method of claim 11 , further configured to determine entering the measurement relaxation state based on a reference signal received power (RSRP) value exceeding a threshold.

17. The method of claim 11 , further comprising performing a measurement based on the measurement relaxation criteria.

18. 20. The method of claim 17, wherein the measurements include an L3 reference signal received power (RSRP) measurement variation or an associated reference signal (RS) measurement for an L3 RSRP measurement.

19. performing a measurement based on said measurement relaxation criteria; comparing the measurement to one or more thresholds, the one or more thresholds including a signal to interference ratio (SINR) threshold, a reference signal received power (RSRP) threshold, a received signal strength indicator (RSSI) threshold, a reference signal received quality (RSRQ) threshold, and / or a change in RSRP within a certain time limit, and / or a low mobility criterion such as a cell change count; determining whether the WTRU has changed a measurement mitigation state based on the comparison; and 20. The method of claim 17, further comprising:

20. receiving a first activation command indicating that the WTRU may start performing radio link monitoring (RLM) or beam failure detection (BFD) after transmitting the first report; receiving a second activation command indicating that the WTRU may start performing radio link monitoring (RLM) or beam failure detection (BFD) after transmitting the second report; The method of claim 11 , further comprising:

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