Method for easing radio link monitoring requirements in a wireless system - Patents.com

Abstract

A wireless transmit / receive unit (WTRU) may comprise a processor and a 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 prohibition time period for reporting a measurement relaxation state. The WTRU may determine that a measurement relaxation state of the WTRU has changed based on the measurement relaxation criteria. The WTRU may determine that the prohibition time period has expired. The WTRU may transmit a report based on the determination that the measurement relaxation state has changed and that the prohibition time period has expired. The report may include an indication of the measurement relaxation state.

Description

[Technical field]

[0001] (Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 292,293, filed December 21, 2021, which is incorporated by reference herein in its entirety. [Background technology]

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

[0003] In one or more methods, systems, and / or apparatus, there may be relaxation of radio link monitoring in a wireless system. In some cases, MAC CE or L1 signaling may be used to report on the uplink and / or enable / disable on the downlink to dynamically provide network control. In some cases, abbreviated uplink reports may be used indicating a simple binary condition as to whether a reporting or relaxation criterion is met. For example, the report may be a single bit. For example, the report may include a limited number of multiple bits to provide more information, such as whether an individual criterion is met. In some cases, dynamic downlink control may 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 memory may be configured to receive configuration information indicating measurement relaxation criteria for radio link monitoring (RLM) or beam failure detection (BFD) and a prohibition time period for reporting a measurement relaxation state. The WTRU may determine that a measurement relaxation state of the WTRU has changed based on the measurement relaxation criteria. The WTRU may determine that the prohibition time period has expired. The WTRU may transmit a report based on the determination that the measurement relaxation state has changed and that the prohibition time period has expired. The report may include an indication of the measurement relaxation state.

[0005] The WTRU may start the inhibit time period when the WTRU sends the report. The WTRU may be inhibited from changing the measurement mitigation state while the inhibit timer is running.

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

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

[0008] The WTRU may perform RLM and / or BFD measurements using the first periodicity when the WTRU is not in a measurement-relaxed state, and the WTRU may perform RLM and / or BFD measurements using the second periodicity when the WTRU is in a measurement-relaxed state.

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

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

[0011] The method may further include initiating an inhibit time period when the WTRU sends the report. The method may further include inhibiting changing the measurement mitigation state while an inhibit timer, which may track the inhibit time period, is running.

[0012] The report may indicate whether the WTRU is in a measurement relaxed state or whether the WTRU is not in a measurement relaxed state.

[0013] The method can include indicating that the measured relaxation state is unique to the first cell.The method can include indicating that the measured relaxation state is unique to the second cell.

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

[0015] The method may include performing RLM or BFD measurements using a first periodicity when the WTRU is not in a measurement relaxation state. The method may 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 the measurement relaxation state based on the power measurement being above a power threshold. The method may include determining to exit the measurement relaxation state based on the power measurement being below a power threshold. [Brief description of the drawings]

[0016] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which like reference numbers indicate similar elements and in which:

[0017] [Figure 1A] FIG. 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] FIG. 1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A, according to one embodiment. [Figure 1C] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A, according to one embodiment. [Figure 1D] FIG. 1D is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communications system illustrated in FIG. 1A, according to one embodiment. [Diagram 2] FIG. 2 illustrates an example of a signaling message sequence associated with relaxed operation. [Diagram 3] FIG. 3 illustrates an exemplary flow chart illustrating a method for mitigation operations. [Figure 4] FIG. 4 shows an example flowchart illustrating a procedure performed by a WTRU to determine measurements based on mitigation criteria, when to enter (or exit) an mitigation state, and how to report when the mitigation state has been entered (or exited) to the network and / or cell. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. Communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. Communications system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communications 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 filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0019] 1A, communications 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, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of 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 as a station (STA), may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, landline or mobile subscriber units, subscription-based units, pagers, mobile phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain contexts), home electronic devices, devices operating in commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0020] 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 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, 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 eNodeB (eNB), a Home Node B, a Home eNodeB, a next generation Node B such as a gNodeB (gNB), a new radio (NR) Node B, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each illustrated as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

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

[0022] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via 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).

[0023] More specifically, as noted above, the communications system 100 may be a multiple access system, but may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a and the WTRUs 102a, 102b, 102c of the RAN 104 may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communications 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 ​​Uplink (UL) Packet Access (HSUPA).

[0024] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may 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 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 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, e.g., using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to and from 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 a wireless technology 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), or the like.

[0028] 1A may be, for example, a wireless router, a Home Node B, a Home eNode B, or an access point, but may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as a location of a business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. 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 one 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 establish a picocell or a femtocell using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 through the CN 106.

[0029] The RAN 104 may communicate with the CN 106, which may be any type of network configured to provide voice, data, application, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as, for example, different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 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 shown in FIG. 1A, it will be appreciated that the RAN 104 and / or the CN 106 may communicate directly or indirectly with other RANs that use the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize NR radio technology, the CN 106 may also communicate with another RAN (not shown) employing GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0030] The CN 106 may also serve 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 providing 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) of the TCP / IP Internet protocol suite. The networks 112 may include wired 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 that may use the same RAT as the RAN 104 or a different RAT.

[0031] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a, which may employ a cellular-based wireless technology, and a base station 114b, which may employ an IEEE 802 wireless technology.

[0032] 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1B, 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 understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0033] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), multiple 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 may perform signal coding, 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 FIG. 1B illustrates the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

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

[0035] 1B as a single element, 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.

[0036] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. 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, and may receive user-entered 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 non-removable memory 130 and / or 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 memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

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

[0039] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, information from the GPS chipset 136, the WTRU 102 may receive location information from 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 being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable location determination method while remaining consistent with an embodiment.

[0040] The processor 118 may further be coupled to other peripherals 138, which may include one or more software 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 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 and / or augmented reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors. The sensor 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, and the like.

[0041] The WTRU 102 may include a full-duplex radio where the transmission and reception of some or all of the signals (e.g., associated with a particular subframe of both the 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 to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., via a separate processor (not shown) or via processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio where the transmission and reception of some or all of the signals (e.g., associated with a particular subframe of either the UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be simultaneous and / or together.

[0042] 1C is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As mentioned above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the CN 106.

[0043] The RAN 104 may include eNodeBs 160a, 160b, 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, the eNodeB 160a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

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

[0045] 1C may 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 illustrated as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0046] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attachment of the WTRUs 102a, 102b, 102c, etc. 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.

[0047] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNodeB handover, triggering paging when DL data is available to the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0048] The SGW 164 may be connected to a 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.

[0049] 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 communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0050] Although the WTRU is depicted in FIGS. 1A-1D as a wireless terminal, in certain representative embodiments, it is contemplated that such a terminal may use a wired communications interface (e.g., temporarily or permanently) with the communications network.

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

[0052] A WLAN in infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP may have access or interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic within the BSS and / or outside the BSS. Traffic originating from outside the BSS to the STA may arrive through the AP and be delivered to the STA. Traffic originating from the STA to a destination outside the BSS may be sent to the AP and transmitted to the respective destination. Traffic between STAs within the BSS may be sent, for example, through the AP, where the source STA may send traffic to the AP, which may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) the source STA and the destination STA using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may be referred to herein as an "ad-hoc" communication mode.

[0053] When using an 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit a beacon 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 dynamically configured width. The primary channel may be the operating channel of the BSS, but may be used by STAs 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. With CSMA / CA, STAs (e.g., all STAs), 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.

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

[0055] A Very High Throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. A 40 MHz and / or 80 MHz channel may be formed by combining multiple contiguous 20 MHz channels. A 160 MHz channel may be formed by combining eight contiguous 20 MHz channels or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, after channel encoding, the data may pass through a segment parser that may split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time domain processing 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] Sub-1 GHz operation modes are supported by 802.11af and 802.11ah. The channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter-type control / machine-type communications (MTC), such as MTC devices in macro coverage areas. MTC devices may have limited capabilities, including certain capabilities, for example, support for (e.g., support only for) certain and / or limited bandwidths. The MTC device may include a battery that has a battery life above a threshold (eg, to maintain a very long battery life).

[0057] WLAN systems that may support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that may be designated as a primary channel. 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 configured and / or limited by the STAs among all STAs operating in the BSS that support the smallest bandwidth operating mode. In an 802.11ah example, the primary channel may be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only) 1 MHz mode, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. For example, if a STA (that only supports 1 MHz mode of operation) transmitting to an AP has a busy primary channel, all of the available frequency bands may be considered busy even if most of the available frequency bands are idle.

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

[0059] 1D is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As mentioned above, the RAN 104 may employ NR radio technology and communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the CN 106.

[0060] The RAN 104 may include gNBs 180a, 180b, 180c, although it will be understood that the RAN 104 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 an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may transmit and / or receive wireless signals to and from the WTRU 102a, for example, using multiple antennas. In one embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or gNB 180c).

[0061] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable numerology. For example, the 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 transmission time intervals (TTIs) of varying or scalable lengths (e.g., including varying numbers of OFDM symbols and / or varying lengths of absolute time durations).

[0062] 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 without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize 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 unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate with and connect to a gNB 180a, 180b, 180c while also communicating with and connecting to another RAN, such as an eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0063] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support for network slicing, DC, interworking between NR and E-UTRA, routing of user plane data to User Plane Functions (UPFs) 184a, 184b, routing of control plane information to Access and Mobility Management Functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D, the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.

[0064] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. Although the foregoing elements are illustrated as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0065] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via an N2 interface and may function as a control node. For example, the AMF 182a, 182b may be responsible for user authentication of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling different protocol data unit (PDU) sessions having different requirements), selection of a particular SMF 183a, 183b, management of registration areas, termination of non-access stratum (NAS) signaling, mobility management, etc. The network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service utilizing the WTRUs 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 massive mobile broadband (eMBB) access, services for MTC access, etc. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 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.

[0066] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 106 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 106 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions, such as managing and assigning UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing DL data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0067] The UPFs 184a, 184b may connect to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via an 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 UPFs 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 DL packets, providing mobility anchoring, etc.

[0068] The CN 106 may facilitate communication with other networks. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may 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] 1A-1D and the corresponding description thereof, one or more or all 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 devices described herein may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

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

[0071] The one or more emulation devices may perform one or more functions, inclusive, while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in test scenarios in a test lab and / or in an undeployed (e.g., test) wired and / or wireless communication network to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, for example, one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0072] In a wireless system (e.g., 5G New Radio (NR)), a WTRU may monitor downlink radio link quality based on a reference signal configured as a Radio Link Monitoring Reference Signal (RLM-RS) resource(s) to detect downlink radio link quality of a primary cell (PCell) and primary and secondary cells (PSCells). The configured RLM-RS resources may be all synchronization signal blocks (SSBs), all channel state information reference signals (CSI-RSs), or a mix of SSBs and CSI-RSs. The WTRU may not need to perform RLM outside of an active downlink bandwidth portion (DL BWP). Similarly, the WTRU may evaluate the downlink radio link quality of a serving cell to detect beam failure.

[0073] One method of saving power may include the WTRU relaxing the RLM / BFD requirements. There may be one or more criteria for RLM / BFD relaxation that may address one or more cases. In an example, there may be SSB-based RLM / BFD measurement relaxation in Frequency Range 1 (FR1). In an example, there may be CSI-RS-based RLM / BFD measurement relaxation in FR1. In an example, there may be CSI-RS-based RLM / BFD measurement relaxation in Frequency Range 2 (FR2). In an example, there may be SSB-based RLM / BFD measurement relaxation in FR2.

[0074] The relaxed BFD / RLM requirements can be supported for all deployment scenarios, including New Radio Standalone (NR SA), E-UTRA-NR Dual Connectivity (EN-DC), NR-E-UTRA Dual Connectivity (NE-DC), NR Intra-band Carrier Aggregation (CA), NR Inter-band CA, and New Radio Dual Connectivity (NR-DC).

[0075] With respect to the 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 the serving cell quality and the 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 if the WTRU meets any of the serving cell quality exit condition(s), low mobility exit condition(s), and / or DRX cycle length, it is not allowed for relaxation and the WTRU may exit relaxation mode. The WTRU may perform measurements for a period of time when not in a relaxed state and then perform additional measurements after entering the relaxed state. In an example, if 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 existing RLM / BFD requirements may apply. In examples, when neither the serving cell quality criterion nor the low mobility criterion is configured, the existing RLM / BFD requirements may apply. In examples, in case of dedicated or broadcast signaling to indicate to the WTRU that the WTRU can relax RLM / BFD measurements, one or more of the previous list(s) may be modified. In some examples, in case of good serving cell criterion is predefined, one or more of the previous list(s) may be modified.

[0076] The WTRU may determine to enter the measurement relaxation state based on a power measurement (e.g., RSRP) exceeding a power threshold (e.g., exceeding the power threshold indicates high channel quality). The power threshold may include one or more of an SINR threshold, an RSRP threshold, an RSSI threshold, or an RSRQ threshold. Additionally and alternatively, the WTRU may determine to enter the measurement relaxation state based on a variation in the power measurement (e.g., RSRP variation) falling below a variation / mobility threshold (e.g., falling below the variation threshold indicates low mobility of the WTRU). The variation / mobility threshold may include a change in RSRP within a particular time limit and / or a cell change count. The WTRU may determine to exit the measurement relaxation state based on a power measurement (e.g., RSRP) falling below a power threshold and / or based on a variation in the power measurement exceeding a variation / mobility threshold. For low mobility criteria, one or more of the following may be applied and / or taken into account (e.g., L3 Reference Signal Received Power (RSRP) measurement variation and / or related RS measurements for L3 RSRP measurement):

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

[0078] The RLM / BFD mitigation criteria may be configured by dedicated signaling (e.g., RadioLinkMonitoringConfig) as a baseline where parameters are used instead of predefined and / or implementation-specific scenarios. The Access Stratum (AS) Capability procedure may be used to report the WTRU capability to support RLM / BFD mitigation. The presence and / or absence of configuration for the RLM / BFD mitigation criteria in the signaling may indicate to the WTRU whether the WTRU can and / or should evaluate the criteria.

[0079] In an example, a question may arise as to whether the network (NW) needs to control when the WTRU enters the relaxed state. In one example, radio resource control (RRC) signaling may be used to report and enable the relaxed state. However, this approach may create undesirable overhead to enable / disable in a dynamic manner whenever a criterion is met.

[0080] In an example, Medium Access Control-Control Element (MAC CE) and / or L1 signaling may be used (e.g., by the NW) to dynamically enable / disable RLM / BFD mitigation. The WTRU may be configured to receive signaling that enables the WTRU to send reports. For example, MAC CE and / or L1 signaling may be used by the WTRU to send reports associated with RLM / BFD mitigation to the NW, such as reports that include an indication of whether mitigation criteria have been met.

[0081] 2 shows an example signaling message sequence 200. The WTRU 202 sends RRC radio access capabilities to the gNB 204 at 206. The gNB 204 may configure reporting criteria at 208 using RRC signaling. Once the criteria are met, the WTRU 202 may send an indication to the gNB 204 at 210. Upon receiving an indication that the criteria are met, the gNB 204 may enable RLM / BFD mitigation at 212.

[0082] With regard to mitigation / reporting criteria, in an example, the out-of-sync and in-sync block error rates (BLERs) used for physical downlink control channel (PDCCH) mapping may be as shown in Table 1. [Table 1]

[0083] 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 sync (OOS) and in sync (IS), respectively. Thus, a difference of 5 dB can be defined.

[0084] Radio link monitoring is performed for non-DRX and DRX cases T specific to FR1 and FR2, respectively. Evaluate_out_SSB and T Evaluate_in_SSB In an example, an evaluation period based on SSB may also be defined on the CSI-RS. Thus, in the following examples, the SSB criterion may be used without loss of generality.

[0085] In an example, the evaluation periods for OOS and IS may be evaluated as seen in Table 2. The example seen in Table 2 further considers FR1, and similar requirements may be applicable to CSI-RS. [Table 2]

[0086] As can be seen in Table 2, P is a factor that accounts for gaps that overlap and / or do not overlap with SSB related symbols and can take different values.

[0087] In an example, to perform RLM mitigation, the WTRU may use a first DRX cycle value to determine the requirements (e.g., evaluation period), and the DRX cycle value used may be different from the value of the actual DRX cycle. For example, a scaling method may be used in which the first DRX cycle value may be determined by scaling the actual DRX cycle value (e.g., by an integer). The scaling factor K may be signaled by the network during RRC configuration. In an example, the scaling factor K may be signaled in an activation message. When the WTRU does not have a configured DRX cycle, the mitigation method for mitigation measurements and the first mitigated virtual DRX cycle may be semi-statically configured by the network in the RRC configuration. Furthermore, the first mitigated virtual DRX cycle may be dynamically activated separately by the MAC or DCI using the PDCCH via the activation message.

[0088] In an example, the requirements may be directly scaled. For example, the evaluation period and / or the indication interval may be scaled with a scaling factor. Different requirements may be scaled with different scaling factors. The scaling factor(s) may be signaled by the network during RRC configuration. The scaling factor(s) may be signaled in an activation message.

[0089] In an example, the WTRU may use a value of the virtual DRX cycle while calculating the RLM / BFD requirements, e.g., evaluation period and / or indication interval. The value of the virtual DRX cycle may be different (e.g., larger) than the actual DRX cycle. The virtual DRX cycle may be used when the actual DRX is not configured. A possible set of values ​​of the virtual DRX cycle may be configured by the base station (e.g., gNB). The particular value to use may be indicated by the base station in the activation message and / or may be selected autonomously by the WTRU. For example, when indicated to enter a relaxed state, the WTRU may select one of the configured virtual DRX cycle values. This selection may be the first evaluation period, which may be the lowest in the set of signaled values. The WTRU may then incrementally increase the value (e.g., by selecting a larger configured value).

[0090] Additionally and / or alternatively, the WTRU may follow base station commands, e.g., UP or DOWN, while changing the virtual DRX cycle for RLM evaluation. The base station may send UP or DOWN commands according to the reported cell / beam measurements, while the WTRU may be within relaxed criteria conditions. For example, if the WTRU is configured to be at a minimum configurable virtual DRX cycle and receives a DOWN command, the WTRU may exit the RLM relaxed mode of operation. If the WTRU receives an UP command following a better cell / beam report (e.g., a report indicating a higher beam RSRP than the previous report), the WTRU may move to a subsequent virtual DRX cycle in the configured list with more relaxed measurement sampling for RLM.

[0091] The relaxation criterion for RLM may be a threshold defined as an offset to the OOS and / or IS SINR mapping. This may be, for example, a Y=2 dB 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 may be uniquely defined for the OOS or IS SINR mapping and / or may be set or configured separately for each OOS and / or IS value. The RLM relaxation mode trigger may be based on measurements reaching and remaining above this threshold for a certain amount of time. This time may be defined, e.g., semi-statically configured by the network. This time may also be predefined.

[0092] Once the WTRU meets the condition of low mobility based on RSRP cell measurement variation over a time interval and good cell quality for RLM, the WTRU may report this favorable state of RLM / BFD mitigation to the network.

[0093] In an example, in addition to the serving cell criterion and the low mobility criterion, the mitigation criteria may include, for example, beam switching and / or trigger time (TTT). The beam change count may be detected at the WTRU or the NW. For example, at the WTRU, the beam(s) used for RSRP must remain within a predefined time interval t. The WTRU may report that the TTT criterion is met for a certain duration before triggering the report.

[0094] The mitigation criteria and the reporting criteria may be separate. For example, the reporting criteria may use a lower threshold than the mitigation criteria. In an example, the WTRU may report an indication that the reporting criteria is met. Upon receiving the report, the NW may enable the mitigation. The WTRU may then apply the actual mitigation when the mitigation criteria is met. DL control information may be received, and the control information may have an activation indication.

[0095] The L1 (physical layer) indication interval for OOS and IS in the non-DRX case is T( Indication_interval ) is max(10ms,T RLM-RS,M ), T RLM,M is the shortest periodicity of all configured RLM-RS resources for the monitored cell.

[0096] The L1 (physical layer) indication interval for OOS and IS in the case of DRX is T Indication_interval is Max(10ms,1.5×DRX_cycle_length,1.5×T RLM-RS,M ) and DRX cycle_length is greater than 320ms, T Indication_interval may be configured to be DRX_cycle_length.

[0097] When the network activates the relaxed state, the WTRU applies the relaxation factor K and then adjusts the measurement sampling rate according to T Indication_interval The relaxation factor K may be semi-statically configured by the network, or alternatively, may be indicated by the network in the relaxation state activation.

[0098] For example, T Indication_interval One way to scale T may be to use a virtual DRX relaxation cycle length, which may be defined as the sample measurement periodicity in the relaxed state. In this case, T Indication_interval can be defined as follows: Indication_interval :max(10ms, virtual DRX relaxation cycle length, T RLM-RS、M ).

[0099] In the example, T Indication_interval can be defined as follows: Indication_interval :max(10ms,R*T RLM-RS,M), where R is a scaling factor. If the scaling factor R is not an integer value, it may be rounded up by performing a ceiling operation such as, for example, ceil(R). The scaling factor R may not be an integer value when it is used to scale other measurements or thresholds for RLM Qin, Qout. The scaling factor R may also be a scaling factor for T evaluate The measurement occasions of the period may be linked to a virtual DRX relaxation cycle length. For example, the virtual DRX relaxation cycle length is R*T RLM-RS,M It can be defined as:

[0100] A WTRU capable of RLM / BFD mitigation features may be configured with one or more parameters. For example, the WTRU may be configured with one or more parameters for mitigation via RRC signaling. The WTRU may receive a MAC CE that may configure the parameters, for example, by indicating a value from a set of predefined values. These predefined values ​​may include, for example, a relative threshold Y to IS mapped threshold for good quality of the serving cell, a TTT for signaling an RLM / BFD mitigation readiness state to the network, a counter for an IS over good quality offset threshold that may be reset each time the WTRU samples a measurement below the offset level, and / or a TTT for signaling the network out of an RLM / BFD mitigation state that is signaled when the WTRU samples a measurement where OOS is detected.

[0101] Additionally and / or alternatively, a sampled measurement and / or a defined number of samples below the IS normal operation threshold mapping may signal an mitigation state. Additionally and / or alternatively, an inhibit timer may prevent the WTRU from signaling an RLM / BFD mitigation ready state after signaling out of the RLM / BFD mitigation state. The inhibit timer, which may track an inhibit time period, may be included with the configuration information. The configuration information may also indicate one or more inhibit time periods.

[0102] The mitigation state feature may involve uplink reporting, which may 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., the SINR threshold and / or the low mobility criterion) is met. The base station may configure the reporting criterion. The UL report may include multiple bits (e.g., two bits to indicate the criteria separately). 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 to increase or decrease the level of mitigation. For example, the bits may indicate an increase and / or decrease of the virtual DRX cycle value used for the RLM / BFD requirements in the mitigation 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 mitigation state.

[0103] In an example, the bits may be used to increase and / or decrease the thresholds and / or select a threshold from a set of thresholds. What data the report indicates (e.g., the meaning of the code points included in the report) may depend on whether the NW enabled and / or disabled mitigation. For example, if the NW disabled mitigation, the report may indicate whether the thresholds and low mobility criteria are met. If the NW enabled mitigation, the report may indicate whether the thresholds and low mobility criteria are no longer met. Furthermore, if the NW enabled mitigation, the bits may be set according to different thresholds or may indicate increasing / decreasing the thresholds).

[0104] For dual connectivity carrier aggregation (DCCA), reporting and / or enabling may be performed separately for each serving cell and / or each serving beam. Additionally and / or alternatively, for DCCA, the WTRU may 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. Furthermore, reporting separately for each carrier may imply multiple bits for reporting.

[0105] In an example, a prohibition timer may be applied to the reporting trigger, e.g., the WTRU may be configured to start a prohibition time period when the WTRU sends a report (e.g., to either the MCG and / or SCG). After the WTRU finishes mitigation, a timer may start, and the WTRU may be prohibited from requesting mitigation via a UL report and / or entering mitigation while the timer is running. Additionally and alternatively, the WTRU may be prohibited from changing the mitigation state while the timer is running. The UL report may include whether the WTRU is in an mitigation state. The UL report may include an indication of whether any OOS indications were detected during the mitigation state. The UL report may include an indication of whether a fallback and / or an existing mitigation state has occurred (e.g., whether the WTRU is currently mitigated and whether the criteria are met). New RRC re-establishment cause values ​​may be introduced to explicitly indicate radio link failure (RLF) during mitigation (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).

[0106] In case of DL control, upon reporting the RLM / BFD mitigation ready state to the network, the WTRU may receive an activation command. The activation command may simply activate the mitigation configuration already received by the WTRU through the RRC configuration. Activation may mean, for example, that the WTRU can start implementing RLM / BFD in the mitigation state. Additionally and alternatively, the network may indicate in the activation command a value of the mitigation factor K and / or a value of a virtual DRX cycle that the WTRU may use. The mitigation factor K and / or the virtual DRX cycle value may be applied to the current evaluation period rule, which may be applied to the TE valvate_out Value and TE valvate_in This may affect the value.

[0107] The DL control information can use a single bit to allow and / or disallow mitigation based on the NW knowledge of the deployment. For example, the DL may be configured to only indicate "enable". In that example, the WTRU can autonomously indicate "disable" when the criteria are no longer met and / or when an "exit" criterion is met (e.g., the "exit" criterion specifies when the WTRU is expected to exit the mitigation state).

[0108] The DL control information may indicate multiple mitigation requirements. For example, different requirements are needed to meet SINR thresholds and / or low mobility criteria. The use of multiple bits may indicate these different requirements. In an example, a graduated mitigation may be implemented (e.g., the DL control information may indicate how much mitigation may be). The DL control information may indicate which requirement applies (e.g., to be used with up and / or down requests from the WTRU and / or to increment and / or decrement the mitigation factor K value).

[0109] For DL ​​control, the WTRU indicates that the NW is "authorized" and can relax if the criteria are met. In this case, different threshold(s) may exist for applying reporting and / or relaxation. These different thresholds may be achieved by applying an offset to the configured and / or predefined criteria and / or by signaling separate thresholds. Additionally and / or alternatively, the use of separate thresholds may allow reporting to occur prior to the criteria that allow the WTRU to relax. In this case, the use of separate thresholds may advantageously compensate for processing delays in the gNB and / or propagation delays in case of non-terrestrial networks (NTN).

[0110] DL control may have an additional state where the NW indicates "allowed" even if the criteria are not met and / or not reported. The NW may base this additional state, for example, on low mobility detected in the network. If the indication is based on beam switching, it may be more accurate than cell quality measurements by the WTRU.

[0111] In the case of an RLF, a WTRU (e.g., an NR WTRU) may use counters and / or timers, such as counters N310, N311, and timer T310, to determine when to declare an RLF. For example, upon detecting N310 consecutive OOS indications from the physical layer, the WTRU may start a timer (e.g., T310). While T310 is running, the WTRU may attempt to resynchronize to the current cell. For example, if the physical layer sends N311 consecutive IS indications, the WTRU may stop T310 and consider itself back to IS. If T310 expires before the physical layer sends N311 IS indications, the WTRU may consider that an RLF has occurred. Furthermore, T310 may trigger an RRC re-establishment procedure.

[0112] While performing RLM using relaxed requirements, the WTRU may have its OOS and IS indication periods scaled accordingly, and therefore RLF detection may take longer. To address this situation and avoid network and / or WTRU performance issues, T310 may be scaled. For example, T310 may be scaled according to the same scaling factor for DRX and / or indications to accommodate the same number of IS indications (e.g., T310 timer) within the timer period T311. Additionally and alternatively, the T310 timer may be maintained at the same value and / or the N310 counter may be scaled down to accommodate an OOS indication in the same amount of time, and regular or relaxed requirements may be used. The RLF condition may scale the N311 counter such that the number of IS indications required to satisfy the "RLF recovery" condition is for the same T310, regardless of whether relaxed or normal monitoring requirements are used.

[0113] Additionally and alternatively, a WTRU that meets the RLF conditions while using the relaxed requirements may avoid declaring RLF at this point. Instead, such a WTRU may autonomously fall back to a normal operation mode for RLM and / or restart the RLM timers and counters, and then the WTRU may declare RLF only when the normal operation conditions for RLF are met.

[0114] Although specific counters and / or timers are referenced herein, these references are intended for illustrative purposes only and the associated methods and / or techniques may be applied generally to any counters and / or timers.

[0115] For fallbacks related to mitigation features, in addition to signaling from the RLM / BFD mitigation ready state and / or the RLM / BFD mitigation state, the WTRU may automatically fall back to normal RLM / BFD procedures based on one or more conditions, including, for example, the network configuring new measurements, the network configuring new measurements with gaps, cell activation and / or deactivation in the same cell group, and / or bandwidth portion activation or modification, the WTRU receiving a new RLM / BFD mitigation configuration, upon receiving a new RLM / BFD configuration, the WTRU may have to restart the procedures for entering the mitigation ready state, the WTRU detecting one or more OOS indications, and / or the WTRU detecting that the conditions for the RLM / BFD mitigation state are no longer met, and / or detecting an exit condition and falling back to normal RLM / BFD operation. Additionally and alternatively, separate criteria may be used for entering and exiting the mitigation state, e.g., the mitigation state is enabled if a threshold and hysteresis are met and the mitigation state is exited if below the threshold and / or in the absence of hysteresis. Additionally and alternatively, separate criteria such as TTT may be applied for entering mitigation or reporting criteria, but the exit and / or fallback occurs instantaneously.

[0116] FIG. 3 shows an example flowchart 300 illustrating a method for mitigation operations. At 302, the WTRU may be configured by RRC signaling to enable reporting of RLM / BFD mitigation. The configuration may include an indication of a SINR threshold for determining serving cell quality and / or 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 predefined 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 send an uplink indication (e.g., in the MAC CE) of whether one or more criteria are met. At 310, the WTRU may receive a downlink indication (e.g., in the MAC CE) regarding whether and / or how the WTRU can relax its RLM / BFD requirements. At 312, the WTRU may determine whether mitigation criteria are met. This may include the value of the DL indication and / or may include an indication of 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. The WTRU may then proceed to update reporting criteria based on the configuration and / or measurement requirements in use at 314.

[0117] As described herein, upper layers may refer to one or more layers in a protocol stack and / or a particular sublayer within the protocol stack. The protocol stack may be comprised of one or more layers within the WTRU and / or network node (e.g., eNB, gNB, other functional entity, etc.), where each layer may have one or more sublayers. Each layer and / or sublayer may be responsible for 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, e.g., Layer 1, Layer 2, and Layer 3. For example, Layer 3 may comprise, e.g., one or more of NAS, IP, and / or RRC. For example, Layer 2 may comprise one or more of the following: Packet Data Convergence Control (PDCP), RLC, and / or MAC. For example, Layer 3 may comprise a physical (PHY) layer type of operation. The higher the layer number, the higher the layer is relative to other layers (eg, layer 3 is higher than layer 1).

[0118] In examples, the foregoing may be referred to as layers and / or sublayers themselves, regardless of layer number, and may be referred to as upper layers as described herein. For example, upper layers may refer to one or more of the following layers / sublayers, from highest to lowest, e.g., NAS layer, RRC layer, PDCP layer, RLC layer, MAC layer, and / or PHY layer. Any reference to an upper layer herein in connection with a process, device, or system may refer to a layer that is higher than the layer of the process, device, or system. In examples, references to an upper layer herein may refer to functions or operations performed by one or more layers described herein. In examples, references to an upper layer herein may refer to information transmitted and / or received by one or more layers described herein. In examples, references to an upper layer herein may refer to configurations transmitted and / or received by one or more layers described herein.

[0119] FIG. 4 illustrates an example flow chart illustrating a procedure 400 that may be performed by a WTRU to determine measurements based on mitigation criteria, when to enter (or exit) a mitigation state, and how to report to the network and / or cell when entering (or exiting) a mitigation state. At step 402, the WTRU may receive configuration information. The configuration information may include any combination of measurement mitigation criteria (e.g., a first set of mitigation 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 perform measurements based on (e.g., using) the first set of mitigation criteria (e.g., a first evaluation period and / or a first periodicity) at 404. The measurements may include L3 RSRP measurement variation and / or associated RS measurements for L3 RSRP measurements.

[0120] At 406, the WTRU may compare the measurement to one or more thresholds. The thresholds may include one or more of a power threshold and / or a mobility threshold (e.g., an SINR threshold, an RSRP threshold, an RSSI threshold, an 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, etc.).

[0121] At 408, the WTRU may select a set of mitigation criteria (e.g., the first set of mitigation criteria or the second set of mitigation criteria) based on a comparison between the measurements taken using the first set of mitigation criteria and one or more thresholds. For example, if the measurements are above one or more thresholds, the WTRU may select the first set of mitigation criteria, and if the measurements are below the one or more thresholds, the WTRU may select the second set of mitigation criteria. The second mitigation criteria may include a second evaluation period and / or a second periodicity (e.g., may be different from the first evaluation period and / or the first periodicity). In some examples, the WTRU may use the first mitigation criterion when the WTRU is not in a measurement mitigation state and may use the second mitigation criterion when the WTRU is in a measurement mitigation state, or vice versa.

[0122] At 410, the WTRU may perform measurements based on the set of mitigation criteria selected at 408. At 412, the WTRU may compare the measurements performed at 410 to one or more thresholds to determine, for example, whether a change in mitigation state has occurred (e.g., so that the WTRU can determine whether to change to or from a measurement mitigation state). The WTRU may use different mitigation criteria when the WTRU is in a measurement mitigation state compared to when the WTRU is not in a measurement mitigation state. At 414, the WTRU may determine, for example, based on the comparison performed at 412, whether the WTRU has changed the mitigation state. If the WTRU determines that the mitigation state has not changed, the WTRU may return to 410 and compare the measurements taken using the selected set of mitigation criteria to one or more thresholds.

[0123] If the WTRU determines that the mitigation state has changed, the WTRU may determine at 416 whether the inhibit time period has expired (e.g., whether the inhibit timer is running). As described in more detail herein, the WTRU may be configured to start the inhibit timer based on the inhibit time period received in the configuration information at 402. For example, the WTRU may be configured to start the inhibit timer in response to sending a report (e.g., a UL report) to the network indicating the measurement mitigation state of the WTRU (e.g., whether the WTRU has entered or left the measurement mitigation state), which may be done, for example, at 418. If the WTRU determines at 416 that the inhibit time period has not expired, the WTRU may return to 410 and compare the measurements taken using the selected set of mitigation criteria to one or more thresholds.

[0124] If the WTRU determines that the inhibit time period has expired, the WTRU may send a report to the network that it has entered (or exited) the mitigation state at 418. For example, if the WTRU determines that the inhibit time period has expired, the WTRU may change its measurement mitigation state. In some examples, the WTRU may report a measurement mitigation state indication when the mitigation state changes, when status reporting is enabled, and / or when the inhibit timer is not running. By notifying the network and / or cell when the WTRU has entered and / or exited the mitigation state, the network and / or cell may know when conditions are best and / or when the WTRU can react quickly or slowly.

[0125] At 420, after the WTRU transmits the report, the WTRU may restart the inhibit timer. In an example, the WTRU may start the inhibit time period when the WTRU transmits a report (e.g., a UL report). In some examples, the WTRU may select a set of mitigation criteria for performing measurements (e.g., a first set of mitigation criteria when the WTRU is not in a mitigated state, or a second set of mitigation criteria when the WTRU is in a mitigated state) and then return to 410. The use of an inhibit time period may, for example, prevent the WTRU from entering and leaving the mitigated state too frequently and / or reduce the number of reports (e.g., UL reports) that the WTRU sends to the network.

[0126] Although the features and elements are described above in certain combinations, one skilled in the art will understand that each feature or element may be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and 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 internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, terminal, base station, RNC, or any host computer.

Claims

1. 1. A wireless transmit / receive unit (WTRU) comprising a processor and a memory, The processor and the memory receiving a first radio resource control (RRC) message including configuration information, the configuration information indicating measurement relaxation criteria for measurements associated with radio link monitoring (RLM) or beam failure detection (BFD) and a prohibition timer value associated with reporting measurement relaxation; determining, based on the measurement relaxation criterion being met for at least one serving cell, that the WTRU should operate in a measurement relaxation state for the at least one serving cell, the measurement relaxation state being associated with a measurement evaluation period that is different from a measurement evaluation period of a non-measurement relaxation state, the non-measurement relaxation state corresponding to a normal mode for the measurements associated with RLM or BFD; transmitting a second RRC message including a first report, the first report indicating that the WTRU is operating in the measurement mitigation state for the at least one serving cell by setting a bit to a value indicating that the measurement mitigation criterion is met for the at least one serving cell, the first report including a respective indication of respective measurement mitigation state information for each of a plurality of serving cells; starting the prohibit timer based on determining that the WTRU should operate in the measurement relaxation state when transmitting the first report; determining that the measurement mitigation state of the WTRU has changed for the at least one serving cell based on the measurement mitigation criterion not being met for the at least one serving cell; determining that the inhibit timer is not running; transmitting a third RRC message including a second report, the second report being transmitted based on the determination that the measurement mitigation state has changed and the determination that the prohibit timer is not running, the second report including an indication of the changed measurement mitigation state for at least one serving cell of the plurality of serving cells, the changed measurement mitigation state for the at least one serving cell corresponding to a non-measurement mitigation state; starting the prohibit timer based on a determination that the WTRU should operate in the changed measurement mitigation state when transmitting the second report; receiving an activation message and a set of values ​​associated with a virtual discontinuous reception (DRX) cycle; selecting a first value from the set of values ​​to be associated with a virtual DRX cycle based on the activation message; determining an additional measurement mitigation criterion for measurements associated with RLM or BFD based on the selected first value associated with a virtual DRX cycle; A WTRU configured to perform the following:

2. The WTRU of claim 1 , wherein the measurement relaxation criterion for the at least one serving cell is based on an offset applied to a synchronization metric for the at least one serving cell.

3. The WTRU of claim 1 , wherein the measurement mitigation criterion comprises a low mobility criterion.

4. The WTRU of claim 3 , wherein the low mobility criterion is associated with a reference signal received power threshold.

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