Zero interrupt beam failure recovery and mobility procedures for highly directional systems

Abstract

Beam failure recovery and conditional switching can utilize deployment information about cells / beams. A wireless transmit / receive unit (WTRU) is capable of receiving a beam recovery configuration. The beam recovery configuration can include an indication of a candidate recovery beam, network deployment information, information about a coverage area of the candidate recovery beam, at least one quality criterion, random access channel (RACH) parameters, or any suitable combination thereof. The WTRU can detect a beam failure. The WTRU can select a recovery beam from the candidate recovery beams based on the beam failure and the beam recovery configuration.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 335,462, filed on April 27, 2022. U.S. Provisional Application No. 63 / 335,462 is incorporated herein by reference in its entirety. Background Art

[0003] Since cellular networks are planned networks, the network may know very precisely the deployment of its cells and the beams within those cells. What the network may not know is how a particular device will move from one cell / beam to another. This information may not be generally known to the device itself. In general, a device may not have information about the network deployment in terms of cells and beams and the geographical areas where these cells / beams are active. Summary of the invention

[0004] Described herein are example methods and systems for beam failure recovery and conditional switching with minimal interruptions and disruptions. In an example embodiment, known deployment information about cells / beams from the network may be utilized. The network may provide a limited snapshot of network deployment information to the device and appropriate coordinates for binding cells / beams to geographic locations and orientations. The device may use information from local sensors and interfaces to extract its current geographic parameters and use this information to determine suitable candidate beams for beam recovery procedures and suitable cells for conditional switching. As described herein, a device may include a user equipment (UE), a wireless transmit / receive unit (WTRU), etc. The terms UE and WTRU are used interchangeably herein.

[0005] An example zero-outage beam failure recovery procedure may include the following. The WTRU may provide assistance information about the location / site / panel / field of view (FoV) / application-quality of service (QoS) to the network from local sensors and measurement data. The next generation Node B (gNB) may prepare a zero-outage beam recovery configuration in response to the WTRU assistance information combined with its understanding of the network deployment and send this to the WTRU. The zero-outage beam recovery configuration may include a set of candidate beams for recovery and a mapping of these candidate beams to suitable activity areas (location / site, angular span, WTRU panel) where these beams can be activated with zero outage. After a beam failure event, the WTRU may extract information from local sensors and measurement data to calculate its updated geographic coordinates and orientation. The WTRU may identify a suitable beam recovery candidate based on its determined coordinates / orientation. The WTRU may derive random access channel (RACH) parameters for the selected recovery candidate and may perform a RACH transmission on the selected candidate beam as part of the beam recovery procedure.

[0006] An example zero-interruption conditional handover procedure may include the following. The WTRU may provide auxiliary information about location / location / panel / FoV / application-QoS to the network from local sensors and measurement data. The gNB may prepare a zero-interruption conditional handover configuration in response to the WTRU assistance information combined with its understanding of the network deployment and send this to the WTRU. The zero-interruption conditional handover configuration may include a set of candidate cells. For each cell, a relevant beam index may be provided. For each (cell, beam) pair, a mapping of the (cell, beam) pair to the appropriate geographic coordinates (location / location, angular span, UE panel) may be provided as part of the configuration. After a mobility event (caused by device mobility or mobility in the environment) that results in impaired link quality, the WTRU may use information from local sensors and configured thresholds to calculate its updated geographic coordinates and orientation. The WTRU may derive the highest priority (cell, beam) pair from the network configured mapping against its estimated geographic coordinates. The WTRU may evaluate the CHO execution conditions for the determined (cell, beam) pair. If the conditional handover (CHO) conditions are fulfilled, the WTRU may perform a conditional handover to the determined (cell, beam) by sending a RACH for the candidate (cell, beam) pair according to the configured parameters.

[0007] An example WTRU configured to perform beam failure recovery may include a processor and a transceiver. The processor may be configured to receive a beam recovery configuration via the transceiver. The beam recovery configuration may include an indication of at least one candidate beam, corresponding reference signal information associated with each of the at least one candidate beam, corresponding information associated with each of the at least one candidate beam, or any suitable combination thereof. The information associated with each candidate beam may include an indication of at least one coverage area associated with the corresponding candidate beam of the at least one candidate beam. The WTRU may be configured to detect a beam failure condition. The WTRU may be configured to select at least one of the at least one candidate beams based at least on the beam failure condition, local sensor data, and a corresponding coverage area associated with the selected at least one candidate beam. The WTRU may be configured to transmit configuration information associated with the selected at least one candidate beam. The WTRU may be configured to transmit an indication that the WTRU is capable of beam failure recovery using local sensor data. The beam recovery configuration may include a priority associated with each of the at least one candidate beam. The WTRU may be configured to select at least one candidate beam based on a priority associated with each of the at least one candidate beam. The WTRU may be configured to select at least one candidate beam based on corresponding reference signal information associated with each of the at least one candidate beam. The reference signal information may include a primary synchronization sequence, a secondary synchronization sequence, a synchronization sequence block, a channel state information reference signal information, a random access channel information, or any suitable combination thereof. The information associated with each candidate beam may include global positioning system information, gyroscope information, accelerometer information, or any suitable combination thereof. The information associated with each candidate beam may include corresponding geographic information for each candidate beam, corresponding angular information for each candidate beam, corresponding distance information for each candidate beam, corresponding directional information for each candidate beam, corresponding beamwidth information for each candidate beam, or any suitable combination thereof. The received recovery configuration may include at least one quality criterion associated with each candidate beam. The received recovery configuration may include a random access channel (RACH) parameter. The WTRU may be configured to select at least one candidate beam based on satisfying the corresponding at least one quality criterion. The configuration information associated with the selected at least one candidate beam may be based on corresponding RACH parameters.

[0008] An example method for performing beam failure recovery may include receiving a beam recovery configuration. The beam recovery configuration may include an indication of at least one candidate beam, corresponding reference signal information associated with each of the at least one candidate beam, corresponding information associated with each of the at least one candidate beam, or any suitable combination thereof. The information associated with each candidate beam may include an indication of at least one coverage area associated with the corresponding candidate beam of the at least one candidate beam. The method may include detecting a beam failure condition. The method may include transmitting configuration information associated with the selected at least one candidate beam. At least one of the at least one candidate beam may be selected based on the beam failure condition, local sensor data, and the corresponding coverage area associated with the selected at least one candidate beam. An indication that the WTRU is capable of beam failure recovery using the local sensor data may be transmitted. The beam recovery configuration may include a priority associated with each of the at least one candidate beam. The selection of the at least one candidate beam may be based on the priority associated with each of the at least one candidate beam. The selection of the at least one candidate beam may be based on the corresponding reference signal information associated with each of the at least one candidate beam. The reference signal information may include a primary synchronization sequence, a secondary synchronization sequence, a synchronization sequence block, a channel state information reference signal information, a random access channel information, or any appropriate combination thereof. The information associated with each candidate beam may include global positioning system information, gyroscope information, accelerometer information, or any appropriate combination thereof. The information associated with each candidate beam may include corresponding geographic information for each candidate beam, corresponding angular information for each candidate beam, corresponding distance information for each candidate beam, corresponding directional information for each candidate beam, corresponding beamwidth information for each candidate beam, or any appropriate combination thereof. The received recovery configuration may include at least one quality criterion associated with each candidate beam. The received recovery configuration may include RACH parameters. The method may include selecting at least one candidate beam based on satisfying the corresponding at least one quality criterion. The configuration information associated with the selected at least one candidate beam may be based on the corresponding RACH parameters.

[0009] An example computer-readable storage medium may have executable instructions stored thereon that, when executed by a processor, cause the processor to be configured to facilitate beam failure recovery. A WTRU may include a processor. When the executable instructions are executed, the processor may be configured to receive a beam recovery configuration. The beam recovery configuration may include an indication of at least one candidate beam, corresponding reference signal information associated with each of the at least one candidate beam, corresponding information associated with each of the at least one candidate beam, or any suitable combination thereof. The information associated with each candidate beam may include an indication of at least one coverage area associated with the corresponding candidate beam of the at least one candidate beam. When the executable instructions are executed, the processor may be configured to detect a beam failure condition. When the executable instructions are executed, the processor may be configured to select at least one of the at least one candidate beam based on the beam failure condition, local sensor data, and the corresponding coverage area associated with the selected at least one candidate beam. When the executable instructions are executed, the processor may be configured to transmit configuration information associated with the selected at least one candidate beam. When the executable instructions are executed, the processor may be configured to transmit an indication that the WTRU is capable of beam failure recovery using local sensor data. The beam recovery configuration may include a priority associated with each of the at least one candidate beam. When the executable instructions are executed, the processor may be configured to select at least one candidate beam based on the priority associated with each of the at least one candidate beam. When the executable instructions are executed, the processor may be configured to select at least one candidate beam based on corresponding reference signal information associated with each of the at least one candidate beam. The reference signal information may include channel state information reference signal information, random access channel information, or any suitable combination thereof. The information associated with each candidate beam may include global positioning system information, gyroscope information, accelerometer information, or any suitable combination thereof. The information associated with each candidate beam may include corresponding geographic information for each candidate beam, corresponding angle information for each candidate beam, corresponding distance information for each candidate beam, corresponding orientation information for each candidate beam, corresponding beam width information for each candidate beam, or any suitable combination thereof. The received recovery configuration may include at least one quality criterion associated with each candidate beam. The received recovery configuration may include RACH parameters. When the executable instructions are executed, the processor may be configured to select at least one candidate beam based on satisfying the corresponding at least one quality criterion. The configuration information associated with the selected at least one candidate beam may be based on the corresponding RACH parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A more detailed understanding can be obtained from the following detailed description, which is given by way of example in conjunction with its accompanying drawings. As with the detailed description, the figures in such drawings are examples. Therefore, the drawings and specific embodiments should not be considered limiting, and other equally effective examples are possible and intended. The same reference numerals ("ref." or "refs.") in the drawings represent the same elements.

[0011] Figure 1A is an example system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented.

[0012] Figure 1B is an example of a method that can be used according to an embodiment of the present invention. Figure 1A An example system diagram of an example wireless transmit / receive unit (WTRU) for use within an illustrated communication system.

[0013] Figure 1C is an example of a method that can be used according to an embodiment of the present invention. Figure 1A An example system diagram of an example Radio Access Network (RAN) and an example Core Network (CN) used within the illustrated communication system.

[0014] Figure 1D is an example of an embodiment in which Figure 1A An example system diagram of another example RAN and another example CN used within the illustrated communication system.

[0015] Figure 2 is an example illustration of a timing diagram for a WTRU attach procedure.

[0016] Figure 3 is an example illustration of beam failure detection at the medium access control (MAC) layer.

[0017] Figure 4 is an example illustration of parallel running procedures for beam / cell level mobility.

[0018] Figure 5 This is an example illustration of intra-NR (New Radio) inter-gNB handover.

[0019] Figure 6 It is an example illustration of intra-NR RAN (Radio Access Network) conditional switching.

[0020] Figure 7 is an example illustration of cell coverage with different beam gains.

[0021] Figure 8 is an example illustration of a link budget analysis showing the number of beams and the number of antenna elements required at different carrier frequencies.

[0022] Fig. 9 is an example illustration of Very Massive MIMO (Multiple Input Multiple Output) update beam switching and mobility procedures.

[0023] Fig.10 is an example illustration of mobility resulting from WTRU rotation / orientation.

[0024] Fig.11 is an example illustration of a beam span configuration.

[0025] Fig.12 is an example flow chart for zero-outage beam failure recovery in individual device / external mobility configurations.

[0026] Fig.13 is an example flow chart for zero-outage beam failure recovery in a unified configuration.

[0027] Fig.14 is an example illustration of a beam failure recovery solution in a translational motion scenario.

[0028] Fig.15 is an example illustration of a zero-interrupt configuration for conditional switching (rotational focus).

[0029] Fig.16 is an example illustration of a conditional switch - zero-interruption configuration for translation and rotation.

[0030] Fig.17 is an example illustration of zero-outage beam recovery and conditional switching configuration.

[0031] Fig.18 is an example flow chart for zero-disruption conditional switchover by device and external mobility configuration.

[0032] Fig.19 is an example flow chart for performing zero-disruption conditional handover in a unified mobility configuration.

[0033] Fig. 20A and Fig. 20B Depicted is an example flow diagram for a WTRU configured in zero-out BFR (beam failure recovery) and zero-out CHO (conditional handover) configurations. DETAILED DESCRIPTION

[0034] Figure 1A1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word DFT spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multi-carrier (FBMC), etc.

[0035] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to send and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0036] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device that is configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0037] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSC), radio network controllers (RNC), relay nodes, etc. Base station 114a and / or base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies (which may be referred to as cells (not shown)). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of a licensed spectrum and an unlicensed spectrum. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, a cell associated with base station 114a may be divided into three sectors. Therefore, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0038] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0039] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 115 / 116 / 117. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​UL Packet Access (HSUPA).

[0040] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-APro).

[0041] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0042] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface used by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0043] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0044] Figure 1A The base station 114b in the may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business location, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.11) to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.15) to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or a femtocell. As Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not need to access Internet 110 via CN 106 / 115.

[0045] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the text and video above, the CN 106 / 115 may be configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Figure 1AAlthough not shown in the figure, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0046] The CN 106 / 115 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 that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0047] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0048] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0049] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal decoding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0050] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from the base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, IR, UV or visible light signals. In another embodiment, the send / receive element 122 may be configured to send and / or receive both RF signals and optical signals. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0051] Although the transmit / receive element 122 Figure 1B 1 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.

[0052] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0053] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, or the like. 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 a home computer (not shown).

[0054] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0055] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0056] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, a frequency modulation (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, etc. Peripheral device 138 may include one or more sensors, which may be one or more of the following: 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, and / or a humidity sensor.

[0057] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit 139 for reducing and / or substantially eliminating self-interference via signal processing performed by hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0058] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0059] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0060] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0061] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements is depicted as being part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0062] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach 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.

[0063] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0064] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0065] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0066] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative embodiments, such terminals may (eg, temporarily or permanently) use a wired communications interface with a communications network.

[0067] In a representative embodiment, the other network 112 may be a WLAN.

[0068] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a BSS and one or more stations (STA) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and leading to the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and leading to a destination outside the BSS may be transmitted to the AP to be delivered to the corresponding destination. Traffic between STAs within the BSS may be transmitted by the AP, for example, wherein the source STA may transmit traffic to the AP, and the AP may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source STA and the destination STA (e.g., directly between them) using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0069] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send beacons on a fixed channel (such as a primary channel). The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may listen to the primary channel. If the primary channel is listened / 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.

[0070] High throughput (HT) STAs may communicate using a 40 MHz wide channel, for example, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0071] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and data can be sent by the transmitter STA. At the receiver of the receiver STA, the above-mentioned operation for the 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0072] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support instrument type control / machine type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0073] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (supporting only a 1MHz operating mode) is sending to the AP, the entire available frequency band may be considered busy even if most of the frequency bands remain idle and may be available.

[0074] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0075] Figure 1D 1 is a system diagram illustrating the RAN 113 and the CN 115 in accordance with an embodiment. As noted above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0076] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0077] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable parameter sets. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or Transmission Time Intervals (TTIs) of varying or scalable lengths (e.g., containing varying numbers of OFDM symbols and / or varying absolute time lengths).

[0078] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the evolved Node-B 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more evolved Node-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the evolved Node-B 160a, 160b, 160c may act as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0079] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b, routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0080] Figure 1DThe illustrated CN 115 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0081] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different PDU sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0082] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be based on IP, non-IP, Ethernet, etc.

[0083] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0084] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b via the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and the N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0085] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more simulation devices (not shown): WTRU102a-102d, base station 114a-114b, evolved Node B 160a-160c, MME 162, SGW 164, PGW 166, gNB 180a-180c, AMF 182a-182b, UPF 184a-184b, SMF 183a-183b, DN 185a-185b and / or any other device described herein. The simulation device may be one or more devices configured to mimic one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0086] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communications to perform testing.

[0087] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be utilized in a test scenario in a test lab and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via an RF circuit system (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0088] Wireless communications between one or more user equipments (UEs) and a network are contemplated herein. A WTRU may also be referred to as a wireless transmit / receive unit (WTRU). The terms UE and WTRU may be used interchangeably herein.

[0089] This article describes procedures based on 5G NR (New Radio) beams. The 5G-New Radio (NR) design may be characterized by its ability to operate in two different frequency ranges: sub-6 GHz, referred to as Frequency Range 1 (FR1), and millimeter wave (mmWave), referred to as Frequency Range 2 (FR2). As the availability of the sub-6 GHz range becomes more limited, the mmWave bands with wider bandwidth may become more dominant. This change results in an extension of the FR2 range to 71 GHz in 3GPP Release 17, and the extended range between 51.4 GHz and 71 GHz is referred to as FR2-2.

[0090] The 3GPP 5G NR standard may define new physical layer (PHY) and medium access control (MAC) layer features to support directional communications. Beam management for acquiring and maintaining beams may be among these features. 3GPP 5G NR may also define new initial access procedures to ensure successful directional transmissions. When transmission and reception are occurring over narrow beams, there may be procedures for detecting beam failures and recovering from beam failures. Beam management may include a set of layer 1 (PHY) and layer 2 (MAC) procedures for establishing and maintaining the best beam pair for good connectivity. A beam pair may include a transmit beam and a corresponding receive beam in one link direction.

[0091] Before the WTRU can communicate with the network, the WTRU may perform a cell search and selection procedure and obtain initial cell synchronization and system information. The first step in the process may be to acquire frame synchronization, find the cell identity, and decode the MIB (Master Information Block) and SIB1 (System Information Block 1).

[0092] In case of a multi-antenna system transmitting multiple beams, detecting the beam from the gNB may also be part of the initial access procedure where the WTRU typically detects all beams in the search space. Figure 2 An example timing diagram is shown for a WTRU attach procedure which may include various aspects of beam management.The WTRU may first find a suitable beam, decode the necessary system information through this beam, and then initiate an uplink (UL) connection using the received parameters.

[0093] Beam scanning and initial access procedures may be performed. The gNB may send beams in bursts in all directions at regularly defined intervals. Whenever the WTRU is synchronizing with the network, it may read a synchronization signal block (SSB) and extract the signal. The signal may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS) and / or a physical broadcast channel (PBCH), and a demodulation reference signal (DMRS). For example, the PSS may include one of three possible sequences and / or provide a time estimate. For example, the SSS may include one of 336 possible sequences and / or provide a cell ID (one of 3*336=1008). For example, the PBCH and DMRS may contain a master information block (MIB) and / or include basic information for taking the next step of decoding the system information block (SIB)-1.

[0094] The WTRU may perform beam measurements and determinations. The WTRU may measure beam strength by measuring received signal power via the beam. The measurements in idle mode may be based on synchronization signals, while in connected mode the measurements are based on the Channel State Information Reference Signal (CSI-RS) in the downlink and the Sounding Reference Signal (SRS) in the uplink. The WTRU may periodically search for the best beam using a predefined threshold criterion defined by the gNB and identify the beam with the highest Reference Signal Received Power (RSRP).

[0095] In a process called beam reporting, the best beam identified by the WTRU may be informed to the gNB. The Random Access Channel (RACH) may be an uplink channel used during initial access or when the WTRU is not synchronized with the network and needs to establish synchronization. In idle mode, after the WTRU has selected a beam, there may be one or more RACH intervals for the WTRU with a specific time and frequency offset during which the WTRU may send a RACH preamble. The WTRU may send a physical RACH (PRACH) preamble corresponding to the SS block (synchronization signal block) that identifies the best beam. There may be a one-to-one mapping between the received SS blocks and the sent RACH preamble. This may be a way for the WTRU to report the best beam to the gNB as the gNB can reversely calculate the best beam through which the WTRU may have received the best synchronization signal when receiving the RACH in a given interval.

[0096] The process by which the network configures the WTRU to perform certain measurements and report them at preconfigured intervals may be referred to as measurement reporting. In connected mode, when the WTRU is already connected to the gNB and active data transfer is ongoing, the WTRU may report beams to the gNB via measurement reporting.

[0097] The WTRU may perform beam switching. Switching from one beam to another may be referred to as intra-cell mobility or beam level mobility. The WTRU may perform beam switching based on the trigger conditions and configured beam switching algorithm for the beam. For example, the WTRU may be in connected mode and perform beam switching through L1 / L2 procedures. On the other hand, the WTRU may use switching for inter-cell mobility, typically through L3 procedures.

[0098] Described herein are 3GPP procedures for detecting beam failure (recovery) and radio link failure. In an example embodiment, the WTRU may perform beam failure detection and recovery (BFDR). When the WTRU and gNB are communicating over narrow beams, WTRU mobility and changes in the environment may cause degradation of the beam pair. Beam level measurements and continuous evaluation may be procedures to help maintain and switch to the best beam pair between the WTRU and the gNB. These procedures may be collectively referred to as beam failure detection and recovery (BFDR).

[0099] When the quality of a beam degrades, the WTRU's PHY layer may generate a "Beam Failure Instance (BFI)" when the measurement result from the configured reference signal for this beam drops below a configured threshold. The MAC layer may maintain a "Beam Failure Instance Counter". The MAC layer may increment the BFI counter and reset the "Beam Failure Detection Timer" for each instance of the physical layer reporting a BFI. If the BFI counter exceeds the configured value, a beam failure may be detected. Beam Failure Detection (BFD) may occur within the Beam Failure Detection Timer.

[0100] Figure 3 Two example scenarios with beam failure procedures are shown. In one example, the upper sub-diagram may show a case where the MAC layer does not generate a beam failure because the timer expires when it receives the BFI from the PHY layer. In another example, the lower sub-diagram may show a case where the PHY layer is reporting BFI at a rate that does not let the timer expire and the BFI counter reach the BFD threshold, and the MAC layer will generate a BFD.

[0101] After detecting a beam failure event, the WTRU may initiate a beam failure recovery (BFR) procedure. Once a beam failure has been detected, the WTRU may try to recover from the beam failure if candidate beams are configured. The WTRU may try to validate the configured candidates for a given serving cell based on configured / defined measurement quality criteria and thresholds. The WTRU may prepare a BFR MAC-CE or a truncated BFR MAC-CE based on the defined conditions that the cell and recovery beam are indicated for network awareness.

[0102] The actual beam recovery process may differ depending on whether the beam failure is detected on a SpCell (special cell) or on a SCell (secondary cell). For the beam recovery procedure on the SpCell, after confirming the configured candidate beams, the WTRU may select an appropriate confirmed candidate beam for RACH transmission. The WTRU may transmit a normal or truncated BFR MAC-CE as part of the RACH procedure. The RACH transmission may follow the parameters configured as part of the candidate beam configuration. A successful RACH transmission lets the network know that the WTRU has recovered with this candidate beam. For the beam recovery procedure on the SCell, after the candidate beam has been confirmed, the WTRU may send a BFR MAC-CE or a truncated BFR MAC-CE to the network. The WTRU may not initiate a RACH procedure for beam failure recovery on the SCell.

[0103] In one embodiment, the WTRU may perform a radio link failure procedure. The WTRU may perform radio link monitoring (RLM) based on a synchronization signal block (SSB) or / and a channel state information reference signal (CSI-RS) and a signal quality threshold configured by the network. The PHY layer at the WTRU may make measurements and pass them to the MAC layer and the RRC layer. The MAC layer may be responsible for detecting beam failures, while the RRC layer may be responsible for detecting radio link failures (RLF). The network may use RRC signaling to configure the WTRU with an RLM reference signal (RLM-RS) and related thresholds. The RLM-RS may be an SSB, or a CSI-RS, or a combination of both. The network may configure a timer to be used for RLF detection / determination as part of the primary cell configuration. When the radio link quality belonging to all monitored RSs is worse than the configured threshold, the PHY layer may generate an "out of synchronization (OOS)" indication. When the radio link quality belonging to at least one monitored RS is better than the configured threshold, the PHY layer may generate an "in sync" indication. The in sync indication and the OOS indication may be passed to the RRC layer.

[0104] Example criteria for declaring RLF may include (1) T310-based RLF, (2) T312-based RLF, (3) random access procedure failure, (4) failure in beam failure recovery procedure, and (5) RLF due to maximum number of retransmissions from the radio link control (RLC) layer. In one embodiment, T310-based RLF may be based on link quality measurements (using SSB and / or CSI-RS). If consecutive out-of-sync indications (e.g., measurements below a given threshold) are received a preset number of times (N310 times), the RLF timer T310 may be started. If the channel quality recovers before the T310 timer expires, the T310 timer may be reset; otherwise, RLF may be declared when the T310 timer expires. In another embodiment, T312-based RLF may include the WTRU starting the T312 timer upon triggering a measurement report that triggers the T310 timer is already running. The T312 timer may allow the WTRU to distinguish between RLF caused by a handover failure or RLF caused by a coverage hole. The T312 timer may typically be shorter than the T310 timer. Thus, if the channel quality of the source gNB is worse than a threshold, the shorter T312 timer may expire earlier and an RLF may be declared in a timely manner. In another embodiment, a random access procedure failure may include declaring an RLF if multiple RACH attempts to connect to the gNB fail consecutively. In another embodiment, a failure in a beam failure recovery process may include an indication that a failure in recovering to a fitting beam after detecting a beam failure resulted in a link failure.

[0105] When beams and links are degrading, BFDR, RLM and handover procedures can run concurrently, such as Figure 4 As illustrated. Each individual procedure may result in RLF. When the WTRU is configured to use conventional handover (HO), link interruption may interrupt measurement reporting and / or HO initiation. Therefore, the HO operation may fail. In parallel, the BFDR procedure may attempt to recover through BFR. If the recovery attempt fails, the BFDR procedure may declare RLF. When the WTRU is configured to use conditional handover (CHO), for example, once the serving link begins to degrade, the WTRU may evaluate the execution conditions for conditional handover and may switch to the target cell if the execution conditions are met.

[0106] Figure 5 An example depiction of an intra-NR inter-gNB handover is shown. Figure 5NR cell level mobility procedures are performed as depicted. Inter-NR gNB handover may also be referred to as legacy handover in the following description. When the WTRU 102 is in RRC connected mode, cell / gNB level mobility may require triggering explicit RRC signaling. When the neighboring cell quality is better offset within a preset duration of the trigger time (TTT), the WTRU 102 may report (502) the cell quality measurement results to its serving (source) cell (e.g., source gNB 501). Different events referred to as A1, A2, A3, A4, A5, etc. may be defined for WTRU measurement report triggering. TTT and cell-specific offsets may be specified during the measurement configuration step. If a handover (HO) decision 504 is made based on the measurement report (502), the source gNB 501 may issue a handover request (506) to the target gNB 503. If the WTRU 102 is admitted by the target gNB 503 (508), the target gNB 503 may transmit a handover request acknowledgment (510) to the source gNB 501, which may include an RRC message to be transmitted to the WTRU 102. Next, the source gNB 501 may initiate a handover (512) and may transmit an RRC reconfiguration message to the WTRU 102. The RRC reconfiguration message may include a set of dedicated RACH resources. The source gNB may maintain the functionality of delivering data from the core network (514) to the WTRU through the target gNB. The source gNB may transmit an early state of the sequence number to the target gNB (518) and the target gNB may transmit an acknowledgment (518). After this step, the source gNB may begin to pass downlink (520) data for the WTRU to the target gNB, which is buffered at the target gNB (524). Finally, the WTRU 102 may synchronize to the target cell (522) and complete the RRC handover procedure (526). The target gNB may notify the source gNB of the HO success (528) and the source gNB may pass the sequence number status to the target gNB (530). The source gNB may be providing DL data to the target gNB (532) until a path switch occurs in the core network (534). The target gNB may send a message to the source gNB that the WTRU context is released (536) after the path switch.

[0107] The HO procedure may fail due to poor channel quality of the target gNB, the source gNB, or both. In scenarios with directional links, handover issues may be exacerbated because the link quality of the target and source gNBs may suddenly deteriorate due to a mobile blocker or WTRU rotation. First, blocking of the target gNB during the handover procedure may lead to a handover failure (HOF). When the WTRU receives the RRC reconfiguration message, the handover failure timer T304 may be started. If the T304 timer expires before the handover is completed, a HOF may be declared and the WTRU may perform connection reestablishment. Second, after a sudden WTRU rotation or blocking, the source gNB may not be able to initiate a handover procedure in a timely manner based on the most recent measurement reports. Even measurement reports from the WTRU may be lost due to poor link quality. Therefore, without handover assistance from the source gNB, the WTRU may need to wait for the source gNB to recover from the interruption or declare an RLF even when there is a potential target gNB with good channel quality.

[0108] Dual Active Protocol Stack (DAPS) handover may be performed. As a potential solution to target gNB blocking, a Dual Active Protocol Stack (DAPS) handover may be performed. In a DAPS handover, the WTRU may not release the source cell connection until the random access to the target gNB is completed. If the target gNB link degrades before the random access is completed, the WTRU may fall back to the source gNB.

[0109] Figure 6 This is an example of NR intra-RAN conditional handover. Figure 6 Conditional Handover (CHO) is performed as depicted. To resolve blocking of the source gNB, Conditional Handover (CHO) may be performed. In CHO, the WTRU may be configured to perform a handover when one or more handover execution conditions are met. The source gNB may proactively configure the WTRU to evaluate the CHO execution conditions defined for the candidate gNB. Once the conditions are met, for example, when the target gNB is better offset from the source gNB than the source gNB, the WTRU may initiate a handover to the target gNB without signaling from the source gNB. Therefore, even when the source gNB is in an outage state due to sudden blocking or rotation, the WTRU may still successfully complete the handover with the target gNB if the CHO execution conditions are met. Figure 6The overall CHO procedure is illustrated in FIG. 1. The WTRU (102) may report (602) cell quality measurements to its serving (source) cell (e.g., source gNB 601). Different events referred to as A1, A2, A3, A4, A5, etc. may be defined for WTRU measurement report triggers. The source gNB may make a CHO decision (604) to one or more target gNBs (603 and 605). The source gNB (601) may issue a handover request (606) to the target gNB 603 and a request 608 to the target gNB 605. If the WTRU 102 is admitted (610, 612) by the target gNB (603, 605), the target gNB (603) may transmit a handover request confirmation (614) to the source gNB (601), which may include an RRC message to be transmitted to the WTRU (102). Next, the source gNB (601) may provide the CHO configuration to the WTRU (102) by transmitting an RRC reconfiguration message to the WTRU (102). After receiving the CHO configuration, the WTRU 102 may begin evaluating the CHO conditions (622). If the CHO conditions are met (624) for one of the configured target cells, such as the target gNB (603), the WTRU 102 may detach (601) from the source cell and synchronize (624) to the target gNB (603). The successful synchronization may mark the CHO complete from the WTRU perspective (628). The target gNB (603) may transmit a handover request (630) to the source gNB, which responds by providing an SN status (632). The source gNB may still be providing DL information (634) to the target gNB (603, 605) until a path switch occurs in the core network (638). The target gNB may transmit a WTRU context release (640) message to the source gNB after the path switch.

[0110] While CHO is resilient to mobile blockers and significantly reduces the number of RLFs originating from a rapidly degrading link, the success of CHO may depend on the availability of the candidate gNB before the failure of the source link, the link quality of the target link, and the conditional thresholds for the target gNB. Even if a candidate gNB exists, the WTRU may need to be able to maintain link quality with the selected candidate gNB until the handover is completed. In addition, careful configuration of the conditional thresholds for handover execution may also be required. Higher thresholds may result in the WTRU failing to perform a handover to the target gNB in ​​a timely manner, resulting in a failed handover. On the other hand, lower thresholds may result in suboptimal selection of a new serving gNB and potentially result in a useless handover in some cases.

[0111] With respect to requirements at higher carrier frequencies, propagation at higher frequency bands may be more challenging than at lower frequency bands. High propagation losses at higher frequencies may require the use of high antenna gains in conjunction with narrow beam based directional (beamforming) transmissions. To increase antenna gain over wide sector beams, larger antenna arrays (number of antenna elements ranging from tens to hundreds) may be used to form high gain beams. Figure 7 An example of the impact on coverage and path loss compensation by using narrow beams at higher frequencies is shown in Figure 1. In such directional systems, since the spatial coverage of each Tx (transmit) beam is limited, multiple beams may be required for transmitting DL common channels (e.g., system information, paging, etc.) to cover the entire cell area. The number of concurrent high-gain beams that a gNB can support may be limited by the cost and complexity of the utilized transceiver architecture.

[0112] As the carrier frequency increases, the number of beams required to cover the entire cell may increase due to the higher beamforming gain required to overcome the propagation loss limitations. Figure 8 As shown, a link budget analysis may be performed to estimate the number of beams required for multiple sectors covering + / - 45 degrees at different mmWave carrier frequencies. As the carrier frequency increases, the number of required beams required to cover the sectors may increase.

[0113] At higher frequencies, due to high attenuation and path loss, larger antenna arrays (number of antenna elements ranging from tens to hundreds) may be used to form high gain and narrower beams (e.g., directional transmission) required to increase coverage distance. As frequency increases, the beams may become narrower. Highly directional links resulting from narrower beams at both the WTRU and the gNB may be more sensitive to dynamic changes in the environment than conventional links. One dynamic change may be caused by WTRU rotation from rotational movement of head mounted devices / wearable devices such as smartphones, game controllers, and VR / XR (virtual reality / extended reality) head mounted devices, etc. WTRU rotation may result in channel changes between the serving gNB and the WTRU, which may cause beam misalignment or even link / connection failures. Other types of dynamic changes may arise from translational mobility, rotational mobility, or a combination thereof. Yet another type of change may occur when the serving link / beam may be blocked by moving objects other than the device itself in the absence of any type of device-related mobility. This may require the target device to be served at the same location / location through some kind of redundant link. Future applications with strict QoS goals may need to recover faster from such failure scenarios regardless of the cause, otherwise there is a risk of not meeting QoS goals and impaired user experience.

[0114] A WTRU experiencing high mobility (translation or rotation or blocker mobility or any combination of prior mobility factors) may not always be able to detect, measure and report the beam that is becoming important and could potentially be configured as a candidate serving beam for the BEAM_RECOVERY procedure. The consequence of such missing reporting may be that the gNB is not able to configure the most suitable beam candidate for the beam recovery procedure. Therefore, the gNB configuration may not ensure BEAM_RECOVERY for a WTRU experiencing beam failure after such high mobility occurs.

[0115] Very high mobility related to the device itself (translation, rotation, or a combination of both) or to the communication environment near the device may also cause problems when mobility requires a cell change. 3GPP has defined conventional (legacy) handovers to implement cell changes in mobility. A successful conventional handover may cause impaired link quality before a fully functional link is established with the new serving cell—a stage of impaired link quality that cannot meet the required QoS is referred to as an "interruption" in this disclosure. When a conventional handover is unsuccessful, the WTRU may resort to the RRC connection reestablishment procedure. While the WTRU can make the connection secure through this procedure, the RRC connection reestablishment procedure may result in much greater delays and potential loss of data. In the event of a connection reestablishment failure, the WTRU may perform cell selection from scratch as part of the initial synchronization with the worst interruption. High mobility resulting from various factors as detailed above may lead to more failed handover scenarios, resulting in failure of RRC connection reestablishment and even reestablishment. For applications / services running on such devices, the above process may result in very large interruptions.

[0116] With the advent of new concepts like ultra-massive MIMO (multiple-input multiple-output) and holographic MIMO, TRPs (transmit receive points) can radiate many (e.g., thousands) beams—in Fig. 9 An example is shown in . The introduction of smart reflective surfaces inside / outside buildings and metasurfaces with fine granularity control can add additional dimensions to the number of beams and granularity.

[0117] These surfaces can be made with small superelements. The surfaces can be controlled in terms of phase shift to have extremely narrow beams that focus and track a target object. In the case of extremely narrow beams, even conventional mobility with moderate speeds can result in rapid changes in beams to the point where it is difficult, if not impossible, to update beams and cells using conventional beam recovery mechanisms or conventional switching mechanisms that require active network involvement during each mobility event. Future devices may have mobility levels far exceeding those known to incorporate very large-scale MIMO technology and the resulting thousands of beams may make conventional beam switching, beam recovery, and mobility procedures completely inadequate to meet the requirements of future applications. In such scenarios with nearly thousands of beams and high mobility, it would be impossible for the WTRU to feedback every change in the beam and require network direction to switch because the mobility rate in terms of beam changes may result in extreme signaling overhead and latency that exceeds the requirements of future applications.

[0118] 3GPP defines conditional handover (CHO) to counter scenarios where the previous serving cell has a rapidly degrading link quality. The serving cell may provide the WTRU with the configuration of conditional handover and a set of conditional handover candidates. For each CHO candidate, the conditions for performing HO may be specified together with the configuration of the candidate cell. Typically, the WTRU may report measurement results of non-serving cells of good quality to the serving cell that it is able to detect, and the serving cell may select a suitable candidate cell to be configured as a CHO target. Very high mobility may result in the WTRU being unable to detect, measure and report neighboring cells in an appropriate manner. Inability may limit the network's ability to configure suitable candidate cells for CHO. For services / applications running on the target WTRU device, the lack of CHO configuration or non-execution of CHO may result in very high interruptions.

[0119] Even if the WTRU finds itself within the coverage of a particular beam / cell after mobility which may be one of the configured beams / cells among the configured set, the WTRU may need to establish the presence / coverage / strength of this beam / cell among the configured candidate cells / beams, which may incur delays. Some of these beam / cell switching events may also even require beam / panel switching at the device, further increasing the activation / refinement time before a useful link is established. All these delays may be unacceptable for future applications with strict QoS targets.

[0120] Example embodiments may attempt to minimize mobility related disruptions and interruptions when the WTRU is making transitions to different beams and cells at high mobility. Certain aspects related to very high frequency operation may exacerbate the mobility situation. Antenna arrays / panels with a large number of antennas required to facilitate directional links at higher frequencies may typically have limited angular coverage. For example, many antenna panels operating in sub-THz frequencies may be referenced for 15 to 30 degree beamwidths. This limitation may come from the way these antennas / panels are implemented at different devices and the nature / style of these devices. Therefore, a WTRU with a limited number of antenna array panels may have limited angular coverage. As described herein, the term field of view (FoV) may be used to refer to the angular coverage or angular range of an antenna panel for a given orientation. Rapid changes in the WTRU orientation due to rotation may cause sudden interruptions to the serving / source gNB, and the WTRU may not have discovered nearby available neighboring beams from the same TRP / gNB, from a neighboring TRP, or from a neighboring gNB. Another reason for non-detection may be that the network configures measurements and gaps and the WTRU does not have enough time to make these measurements if configured. Regardless of nearby available beams / cells from the same gNB or from neighboring gNBs, missing configuration for recovery from a beam failure event or for handover to a neighboring cell through configured CHO candidates may result in loss of connectivity and may require greater latency. The loss of connectivity may cause significant disruption to applications running at the WTRU and may degrade QoS metrics. To illuminate the problem from another angle, one may consider some disadvantageous devices with special designs where omni-directional coverage is not available. The unavailability of omni-directional coverage may also arise from low-capability devices with limited antenna panels, limited transceivers, and limited computing power.

[0121] Fig.10An example scenario may be shown where the WTRU is initially communicating with TRP 1. The initial position / orientation of the WTRU may be indicated by "1". The next two orientations may be indicated as "2" and "3". The TRP beams and WTRU beams may be indicated in the figure as blank beams and dashed beams for each TRP and for each WTRU position / orientation, respectively. The WTRU at position 1 may not be able to detect TRP 2 (TRP 3) that is covered in the angular space that does not overlap with the WTRU's beam. Non-detection may also be a result of the network not having time to configure the WTRU for the measurement results and appropriate measurement result gap configuration, etc. At this moment due to mobility, the WTRU position / orientation may become to be in position "2". The WTRU may lose the angular coverage space of TRP 1. In other words, the WTRU may experience a beam failure of its serving beam from TRP 1. At the current WTRU position / orientation "2", the WTRU may be in the coverage space of a suitable beam from TRP 2. Since the WTRU has not yet discovered this beam, the measurement results may not have been reported. The network may not have configured the beam from TRP 2 to the WTRU. The lack of proper configuration in terms of beam restoration and conditional switching may result in large delays before the WTRU will be able to establish a proper connection with the new TRP. The resulting disruption may be unacceptable for services / applications running at higher QoS requirements and may lead to user dissatisfaction.

[0122] Example implementations as described herein may attempt to minimize mobility interruptions / disruptions that allow devices to perform beam recovery and conditional switching in a seamless manner, and interruptions and disruptions during these transition events are minimized. An example implementation called zero-disruption beam failure recovery may target recovery from beam failure events in a deterministic manner with minimal interruptions and disruptions. Since the cellular network is a planned network, the cellular network may have very precise knowledge of the deployment of its cells and the beams within those cells. What the network does not know may be how a particular WTRU will move from one cell / beam to another. In fact, information about how a particular WTRU will move from one cell / beam to another may not be generally known to the WTRU itself. In general, the WTRU may not have information about the network deployment in terms of cells and beams and the geographic areas in which these cells / beams are active. The proposed method may target the known deployment of cells / beams from the network by providing the WTRU with a limited snapshot of the network deployment and appropriate coordinates to bind cells / beams to geographic locations and orientations. The WTRU may use information from local sensors and interfaces to extract its current geographic parameters. The WTRU may use its current geographical parameters to determine suitable candidate beams from the configuration provided by the network. This process may ensure zero-outage beam restoration in case of beam failure.

[0123] In an example embodiment, the WTRU may provide assistance information (described in detail in the following paragraphs) to the gNB. The gNB may use this information to prepare a zero-outage beam restoration configuration. The gNB may provide a zero-outage beam restoration configuration to the WTRU. In case of impaired quality of the serving beam, the WTRU may determine a suitable candidate beam based on data available through its local sensors and potentially in combination with other radio measurements, perform verification, and perform beam restoration with the selected candidate. The assistance information may be a key element in the proposed method, which is first sent to the gNB and used to prepare a suitable configuration for the target WTRU. A novel element to configure the beams may be their association or mapping to the WTRU geographic coordinates or data from sensors plus other radio measurements. The network may provide this configuration to the WTRU. After a beam failure, the WTRU may use information from local sensors, potentially in combination with radio measurements, to determine the most suitable candidate beam based on the configured mapping from the network. In the following, assistance information may be broadly defined. The key steps of the proposed zero-outage beam restoration procedure may be described.

[0124] The auxiliary information from the WTRU may be broadly classified into two groups referred to as measurement-based data and non-measurement-based data. The first group may include all information that can be estimated, measured, determined with or without post-processing of the signals received from the radio interface for which mobility is being considered. The first group may be referred to as measurement-based (e.g., radio measurement-based) data. The first group may include receiving, measuring and processing reference signals on the physical layer, MAC information elements, RRC messages received from the network, or information received at higher layers. The measurement results may be in the form of RSRP (reference signal received power), RSSI (received signal strength indicator), RSRQ (received signal reception quality), SNR (signal-to-noise ratio) or SINR (signal-to-interference and noise ratio).

[0125] The second group may include all information that is not extracted from network signaling. The second group may be referred to as non-measurement-based data. The first subgroup in the non-measurement-based data may include the WTRU's ability to cover its antenna panels and implementation details, the corresponding fields of view of those panels, transceiver and power characteristics, switching delays, and simultaneous operations for panels, etc. The second subgroup in the non-measurement-based data may cover all information extracted or measured by local sensors and interfaces other than the radio interface for which mobility is being considered. Examples of local sensors may include positioning sensors, gyroscopes, accelerometers, etc. Interfaces other than the radio interface under consideration may be wired interfaces like Ethernet, wireless interfaces like Bluetooth, WiFi, or any other proprietary wired or wireless interfaces. However, the third subgroup in the non-measurement-based data may include mobility metrics and configurable triggers. Examples of mobility metrics may be speed (translation and / or rotation), direction (translation and / or rotation), rate, trajectory, or / and history of mobility, etc. Relevant configurable triggers that can help with mobility management and provide appropriate configuration may come from situational or contextual information - for example, a vehicle device (or a device inside) starting its trajectory to a destination, where both the start and the trajectory may be very important from a configuration perspective. Another example may include starting an online game from an AR / VR device that potentially includes a user profile that may incorporate or provide user behavior on a per-turn basis during the game. Such parameters may also be updated by the WTRU when a certain BFR configuration has been received from the gNB. The gNB may also update the BFR configuration upon receiving updated assistance information or other factors from the WTRU.

[0126] In some cases, overlap may occur. For example, similar information may be available in the measurement-based group and the non-measurement-based group. An example may be positioning, where the network provides some positioning information (measurement-based) when the WTRU is equipped with a local positioning sensor that extracts positioning information from any satellite system. In this case, one information set or the other may be used, or both information sets may be combined to achieve better accuracy, granularity, or information quality.

[0127] Having defined assistance information, example steps of the proposed method may be outlined here and further detailed below. The WTRU may provide assistance information to the gNB. This assistance information may incorporate and simplify potential information that the WTRU may measure and obtain through signals received from the network or that the WTRU may obtain through other interfaces or extract from its local sensors. The WTRU may be able to update its assistance information for certain parameters, at least under certain conditions.

[0128] The gNB may provide a zero-outage beam restoration configuration in response to the WTRU assistance information. This configuration may be based on the network deployment of cells, TRPs, beams, and the assistance information provided by the WTRU. The configuration preparation may take into account any historical data about WTRU parameters, application usage, WTRU subscription status, etc. The configuration preparation may use artificial intelligence and machine learning algorithms to use all network and WTRU data to prepare a configuration suitable for the WTRU in a predictive manner.

[0129] The zero outage beam restoration configuration may include a set of candidate beams for restoration and a mapping of these candidate beams to appropriate parameters covering both measurement-based data and non-measurement-based data. As an example, the candidate beams may be mapped to an active area (in terms of location / place, angular span, WTRU panel) where these beams are activated with zero outage. Another example of a measurement-based selection criterion with associated parameters (e.g., thresholds) may be configured for one or more candidate beams.

[0130] After a mobility event (caused by device mobility or mobility in the environment) that results in impaired beam quality or beam failure, the WTRU may use relevant information from radio measurements and non-measurement based data such as from local sensors of the WTRU. The WTRU may identify a suitable beam / cell from the network configured mapping and perform beam failure recovery procedures using this derived candidate beam.

[0131] In the legacy BFR procedure, the WTRU may be transmitting the list of candidate beams in a normal or truncated BFR MAC-CE. For very massive MIMO beam scenarios with high mobility, making measurements on multiple candidates may result in increased interruptions and outage time when the WTRU is transitioning to a new candidate. This may become severe for situations when the WTRU needs to use different antenna panels or use measurement gaps to make such measurements. For this purpose, the zero-outage procedure may circumvent the procedure of making measurements on multiple candidate beams and reporting them to the network.

[0132] The WTRU assistance information may include two groups: one group called measurement-based data and another group called non-measurement-based data. The assistance information may be grouped in different ways. A design compatible with the proposed method may classify the assistance information in data based on radio measurement quantities and data based on non-radio measurement quantities. The first group of data based on radio measurement quantities may include all radio measurement results that can be configured by the radio network. The first group of data based on radio measurement quantities may include all measurement results for NR, E-UTRAN, UTRAN, WiFi, etc. Measurement results related to different RATs (radio access technologies) may include existing measurement quantities, or support for new measurement quantities may be introduced. The second group of data based on non-radio measurement quantities may group all remaining assistance information that may be useful for minimizing interruptions during the beam failure recovery process. The information elements in the second group may include parameters and quantities that the WTRU can provide based on other local interfaces and local sensors, etc. A subset of the second group of data based on non-radio measurement quantities may include a collection of parameters and quantities related to WTRU capabilities and specific implementation details, including but not limited to antennas, panels, detailed implementations regarding antenna panels - e.g., field of view, power characteristics, radiation pattern, architectural details regarding how transceivers are linked to different panels, beam steering capabilities including digital, analog / phase shift and hybrid based, transition times for beam steering and panel switching delays, etc. Mobility related triggers from situational or contextual information - e.g., a vehicle device (or a device inside) starting its trajectory to a destination that helps with mobility management, or a trigger regarding starting a network game from an AR / VR device potentially including a user profile, may also be part of the data based on non-radio measurement quantities.

[0133] In different but compatible groupings of assistance information, three groups may be defined as data based on radio measurement quantities, data based on non-radio measurement quantities, and data based on WTRU capabilities and implementation. In this classification, data based on radio measurement quantities may be the same as previously defined. Data based on non-radio measurement quantities may include all measurements that are not part of the first group and may be made through local interfaces and local sensors, plus mobility triggers that provide situational and contextual information. The third group may include a set of parameters and quantities related to WTRU capabilities and specific implementation details.

[0134] Zero-interruption beam recovery may be performed. The WTRU may have limited discovery of neighboring beams around it for various reasons, and at any moment, the WTRU may find itself when it has not a priori discovered a nearby detectable beam. This may occur if the WTRU performs a rapid translational movement, or it undergoes a large rotation, or a combination of the two. This may also be due to a limited number of antennas, antenna panels, transceivers, or strict requirements on power consumption. These situations and / or aspects may result in limited neighboring beams being discovered and reported to the network by the WTRU. With traditional beam management and beam recovery procedures that typically base configuration on reports of detected beams, the configuration from the network may not be sufficient. The missing beam recovery configuration for the WTRU to discover beams that are detectable nearby may result in the beam failure procedure being unable to allow the WTRU to recover to these beams. Since beam management and radio link monitoring both run in parallel at the WTRU, this may ultimately lead to a radio link failure. The radio link failure may then cause the WTRU to do a cell search and RRC configuration procedure from scratch, which is highly time-consuming and harmful to ongoing traffic flows.

[0135] In the proposed method, the WTRU may provide assistance information to the gNB. This information may include measurement-based data and non-measurement-based data as detailed earlier. Based on the received assistance information, the base station may provide the WTRU with a set of candidate beams around the WTRU's geographical coordinates and a mapping that associates the candidate beams to the new geographical coordinates. The updated geographical coordinates may be any subset of the parameters from the assistance information. These parameters may be considered to be outside the assistance information, but for which the gNB knows that the WTRU will be able to make them known through its local sensors or other interfaces. In a simple example, the mapping of the candidate beams may be provided relative to their directional indication. This directional indication may be in the form of angular coverage relative to a suitable reference beam. Angular coverage may be defined using azimuth, elevation, or a combination of both. The reference beam indication may be part of the configuration. The reference beam may be defined as an SSB beam or a CSI-RS beam. Additionally, the reference beam may be the actual beam that the network is using to serve the WTRU. Instead of a reference beam, other methods may be used to specify the reference direction (e.g., geographic north or some other reference that is understandable to both the network and the WTRU). In one example, orientation information may be given relative to one or more configured TCI states, where the TCI state contains QCL reference information with DL or UL beams / RS. In another example, candidate beams may be provided for mapping against positions and orientations, both indicated with appropriate coordinates and in a suitable quantized form.

[0136] For each beam in the configured set, in addition to its angular span around the WTRU, the gNB may also provide relevant parameters to initiate contention-free RACH access within that beam. This may include RACH parameters such as RACH preamble sequence identity, RACH duration, power ramp parameters, parameters related to RACH opportunities associated with the indicated beam, etc. The configuration may provide RACH parameters for 4-step RACH, 2-step RACH, or both. Additionally, prioritized RACH access parameters may be specified as part of the configuration to speed up beam failure recovery.

[0137]

[0063] Another optimization may be to design special search spaces for beam failure recovery. In one design, these search spaces may have higher periodicity for fast network feedback. They may also be made simpler to reduce WTRU decoding complexity for BFR message exchange.

[0138] For beams configured as part of zero-outage BFR, special procedures may be designed that may provide RACH behavior, for example, providing network knowledge that the WTRU is recovering over a specific beam. These procedures may be changes to the RACH, such as making the RACH faster, more reliable, and faster, or new designs through signaling mechanisms.

[0139] Another approach may be to provide configuration of UL and DL bandwidth portions that are activated and used for beam failure recovery procedures. These may be different from active BWP pre-BFD events.

[0140] The configuration may also include conditions under which the configuration remains valid. The configuration may have a timer and the validity may expire when this timer expires. Another configuration release condition may be associated with mobility, for example, if a configured device moves more than a configured threshold away from its last known position / location, it will release the zero interruption configuration. For this purpose, suitable zones may be created through configuration. The WTRU may track its zones. The exit condition may specify when the configuration is released. An example may include whether the WTRU has just moved out of its current zone. In another example, the configuration may be valid in the current zone and a directly adjacent zone with overlapping boundaries. In this case, if the WTRU moves out of the directly adjacent zone, it may release the zero interruption configuration. In another example, the configuration release condition may be associated with the timing advance value of the device (e.g., with the serving gNB) (e.g., if the device moves and the change in timing advance is above a configured threshold), the device may be configured to release the currently active zero interruption configuration. More generally, any suitable combination of parameters from auxiliary information may be used to define validity conditions and release conditions.

[0141] In another solution, one or more zero-outage configurations may be given to a device. A mapping / association of configurations to zones, locations, or timing advance values / ranges may be given to a device. The device may select a configuration based on tracking of relevant metrics (zone, location, timing advance, etc.).

[0142] For systems based on very large-scale MIMO with the ability to deploy thousands of beams per TRP, in order to contain overhead, the network deployment of beams may follow certain rules and may be provided in a compact form. In one example, the beam deployment may follow a pattern in the azimuth and elevation dimensions. A set of patterns may be known in table form or through a formula. The network may select a suitable pattern for its deployment based on its requirements in a given geographic area. For such cell and beam deployments, the network may provide the WTRU with a compact form of deployment pattern as part of the zero-outage beam recovery configuration. The configuration may include the location of the TRP in appropriate coordinates. A WTRU receiving such a configuration may determine the nearest TRP for any location and then use the pattern indication to determine the beam pattern. Parameters for each constituent beam, its identity, associated reference symbol parameters, RACH timing, RACH preamble and other parameters may also be communicated to the WTRU in a suitable compact form as part of the configuration.

[0143] exist Fig.11 An example configuration is shown for a WTRU communicating with TRP 1. This figure shows the configuration including an indication of the reference direction in the case of the current beam and the neighboring beams with their angular spans. In this example figure, the beam from TRP 2 may be configured with its span marked relative to the reference (beam) direction as a start angle (β2s) and an end angle (β2e). Similarly, the figure may show the start and end angles of an example beam from TRP 3 as β3s and β3e. For each configured beam, the gNB may provide RACH related details to allow CFRA within that beam. The same configuration information may be provided by providing an angle from the reference direction / beam to the center of the candidate beam and additionally providing the beamwidth for each beam. This may be further simplified in the case where the beamwidth is the same for each beam and then a single beamwidth is provided for each candidate beam.

[0144] The PHY layer may report a beam failure indication (BFI) to the MAC layer when the quality of the beam to which the WTRU is attached is included. The PHY layer may generate a BFI indication when the reference symbol associated to a beam drops below a configured threshold. These conditions may be defined on SSB, CSI-RS, or a combination of both. For very large-scale MIMO, there may potentially be new reference symbol structures. One embodiment may be in the form of a layered architecture with narrow beams superimposed on wider beams. There may be multiple layers of such beams of varying widths. Beam failure conditions may be appropriately defined and configured using existing reference symbols or new reference symbols defined for emerging networks with a large number of beams and appropriate thresholds to be evaluated in view of those reference symbols.

[0145] If the WTRU experiences a beam failure, for example as a result of a rapid rotation, the WTRU may take locally available information about the amount of rotation from local sensors and / or gyroscopes. It uses the rotation information and the reference beam / direction indicated by the network to calculate its fresh orientation. The network configuration may have indicated the various beams with their angular coverage. The WTRU may determine the appropriate beam relative to its locally determined orientation after the rotation event. This allows the WTRU to know exactly which beam it should have line-of-sight connectivity with respect to its new orientation. As a result, the WTRU may not need to perform blind decoding and cell search to find an SSB beam, and later perform a long beam refinement procedure to reach a suitable active connection.

[0146] After a suitable beam has been established according to the configuration provided by the gNB, the WTRU may use the configured parameters for beam recovery relative to its newly determined beam. It may transmit a contention-free RACH using the configured RACH parameters over the configured RACH resources linked to the determined suitable beam.

[0147] Fig.12 An example flow chart for a zero outage beam recovery procedure is shown. For a WTRU in an RRC_CONNECTED state (1202), the WTRU may transmit high-level assistance information to the network / gNB (1204). This information from the WTRU may include measurement-based information and non-measurement-based information. The parameters and elements for the two broad categories within the assistance information may have been detailed earlier. In addition, the assistance information may carry information from the WTRU situation / context and running applications that may require unimpaired mobility. This may include some triggers that may indicate that potentially the device may experience a mobility situation that causes an outage. Examples of such triggers may be a car starting to move (which may result in high translational mobility), a head mounted display (HMD) device or other AR / VR widget indicating that a virtual / mixed reality game is starting (where rotational mobility and movement blockers may result in an outage), etc.

[0148] Based on the assistance information, the gNB may provide the WTRU with a suitable configuration for beam recovery (1206). This configuration may include candidate beams and a suitable mapping of these candidate beams to geographic coordinates (including but not limited to location / zone / span, etc.). The network configuration may also include parameters and thresholds (1208) for the WTRU to apply to its updated geographic coordinates (e.g., zone / location / position and span) using local sensors and interfaces in order to select a suitable beam from a suitable TRP using the configured mapping table. The configuration may include two sets of configurations, one set of configurations for handling device mobility where the device may be experiencing translational and rotational movement, and another set of configurations focused on interrupting external mobility that may be a result of the environment rather than direct device mobility. As an example, when a serving beam may be experiencing a failure, the external mobility generated by a mobility blocker may provide a beam / TRP that is capable of providing coverage to a target device whose location / position is known at the gNB. This may require the WTRU / device to switch and activate to a different panel where the gNB may provide instructions as part of the configuration. This indication may in turn be based on the implementation and capabilities of the WTRU's antenna panels, transceivers, switching delays and detailed features as part of its assistance information.

[0149] In a compatible design, a configuration may include two sub-configurations, one of which is suitable for translational mobility and the other for rotational mobility and external mobility (including blocking events in the network). This may be useful in the sense that rotation of the device itself or blocking of a beam due to mobility in the network may require the device to pick a beam with coverage at the same location but with a different orientation.

[0150] In a compatible approach, the network may provide a set of beam restoration configurations to the WTRU. The network may provide associations of these configurations to different applications, different QoS (e.g., different reliability requirements), different power consumption targets at the WTRU, WTRU active service subscription levels, etc. When a beam failure event occurs, the WTRU may select an appropriate beam restoration configuration based on the current situation according to the configured criteria. As described earlier, multiple configurations may be associated to different physical parameters (e.g., external or device mobility), different service reliability targets (one configuration when higher reliability is required and one configuration for lower reliability), different subscription levels (one configuration when the WTRU is using paid content versus one configuration for non-paid content), etc.

[0151] For a WTRU in the RRC_Connected state (1202), the WTRU may transmit assistance information to the gNB (1204). The WTRU may receive zero-outage beam configurations (1206), where one set of configurations is for external mobility and one set of configurations is for device mobility. In the case of mobility that results in impaired quality of the serving beam according to the configured beam quality threshold, the WTRU may extract information from its local sensors (1208). The sensor information may be combined with radio measurements over existing or newly designed reference signals received from the network. An example may be combining local sensor data with measurements performed using downlink positioning reference signals. The WTRU may use this information to select a correct set of candidate beams from the device mobility configuration or the external mobility configuration (1210). The WTRU may map the information from the local sensors into a suitable format for location / area / orientation as configured and then derive its location / orientation. Using this location / orientation, the WTRU can determine the appropriate beam (from the appropriate TRP) from the configured mapping (1222 for external mobility and 1212 for device mobility).

[0152] The entries in the mapping table may provide multiple candidate beams for a given location / orientation. In this case, the gNB may provide a priority order for the candidate beams and also provide a priority order for the TRP. For example, prioritization (e.g., biasing) of beams or / and TRPs may be performed by the network to optimize its load balancing, energy savings, or / and deployment scenarios, etc. The WTRU may determine the most suitable candidate (1224 for external mobility or 1214 for device mobility). The WTRU may verify the quality of the determined candidate 1216 and determine the associated RACH configuration 1218. The WTRU may then perform a beam recovery procedure 1220 on this determined beam using a configured set of recovery parameters. Beam recovery may typically be sending a contention-free RACH using configured parameters (e.g., indicating RACH sequence number, RACH timing, timing, and power ramp).

[0153] In a compatible design for achieving zero-outage beam failure recovery, the configuration for candidate beams may be provided as a unified configuration. In this unified configuration, all candidate beams and their priorities may be provided with their mapping to appropriate geographic coordinates, orientations, and associations with other parameters that the WTRU can extract and use to determine the appropriate beam. This unified configuration may enable coordination of designs that provide candidates that the WTRU can use in the event of a beam failure, independent of the cause of the beam failure (e.g., external mobility or device mobility). Fig.13An example flow chart for zero outage beam failure recovery with unified global configuration is shown. For a WTRU in RRC_Connected state (1302), the WTRU may transmit assistance information to the gNB (1304). The WTRU may receive the zero outage beam configuration (1306). A change here from the previous figure may be that the network configuration for beam / TRP candidates is provided in a unified manner (covering candidates targeting external mobility and device mobility).

[0154] Once the device is experiencing a beam failure, the WTRU may obtain information from its local sensors (1308) to determine whether the link failure occurred due to device mobility or external mobility (1310). This information, combined with information extracted from other interfaces and other sensors, allows the WTRU to select the most appropriate configuration for beam failure recovery (1322 for external mobility and 1312 for device mobility), for example based on its geographic coordinates. The most appropriate configuration may be derived directly from the network configured priorities for each candidate beam for the WTRU's geographic coordinates. The WTRU may select this configuration. The WTRU may need to activate different antenna panels according to the selected configuration. The flowchart may show appropriate panel activation only for the external mobility case, which is undoubtedly more relevant, but activation of appropriate panels may also be required for the device mobility case. In one example, the network may also configure a priority order for the WTRU's antenna panels based on WTRU assistance information transmitted to the network about the supported antenna panels. The WTRU may select the antenna panel according to the configured priority order. In the event that a suitable antenna panel is activated (e.g., in the highest priority case), the WTRU may verify the selected TRP / beam combination according to the configured parameter settings (1316). Quality verification in terms of RSRP, RSRQ, or SINR may be configured using measurement objects of appropriate indications from the selected TRP / beam. If the selected configuration meets the quality criteria, the WTRU may select a RACH configuration associated with the selected TRP / beam (1318) and send a RACH on the derived resources (1320). Although not shown in the flowchart to make the design clear to follow, if the selected TRP / beam does not meet the configured quality criteria, the WTRU may select the next higher priority beam from the provided configurations until it finds the highest priority beam that meets the quality criteria. In the case of prioritization of panels, if the WTRU does not find any suitable beam that meets the quality criteria using the first selected panel, the WTRU may select the next higher priority panel from the provided configurations and find a suitable beam in the given priority order for the beams. To speed up the process, the WTRU may take multiple candidates indicated for the current geo-coordinates and decide the highest priority candidate that meets the quality criteria to trigger the recovery process on this candidate. If the configured candidates do not meet the quality criteria, the WTRU may resort to the traditional beam recovery procedure.

[0155] In the following, two example designs are discussed for zero-outage beam recovery configurations. The first design may propose an independent design for zero-outage BFR. The second design may propose a joint design for traditional and zero-outage BFR. To simplify the description, a limited set of mapping parameters (rotation / orientation aspects) for candidate beams are shown in these designs. It should be understood that additional parameters for candidate beams in terms of geographic coordinates, orientation, other subsets of auxiliary information, and priorities can be indicated in the same manner.

[0156] In this section, a design in which a zero outage BFR information element (IE) is defined as a separate configuration element may be discussed. A zero outage beam failure recovery configuration IE may be introduced as part of the configuration with a new structure that associates each SSB / CSI-RS resource to a reference position / location and an angular span.

[0157] In addition, each candidate beam, whether SSB or CSI-RS based, may be indicated relative to a suitable benchmark to indicate its span. We may introduce a new structure / template where for each candidate beam we provide a reference position / location for the WTRU and its angular span. An example of a zero outage beam failure recovery configuration structure may be provided below. This information element may use traditional parameters such as rootSequenceIndex-BFR, rach-ConfigBFR and / or rsrp-ThreshoholdSSB. ZeroOutage-BFR-SSB-Resource and ZeroOutage-BFR-CSI-RS-Resource may be key parameters for associating candidate SSB / CSI-RS beams to their corresponding active coverage areas through the parameter ZeroOutage-BFR-Map. ZeroOutage-BFR-Map may provide beam coverage in terms of beam-reference-orientation, beam-start-angle, and beam-end-angle parameters. This may be taken as an example and is an additional parameter for defining the area associated to the candidate beam. Below is an example pseudocode for a zero outage beam failure recovery configuration.

[0158]

[0159]

[0160] In this embodiment, each candidate beam may have an indication of its active region as a structure of type ZeroOutage-BFR-Mapping. This may be defined from a measurement-based information element or a non-measurement-based information element using a suitable set of parameters.

[0161] A compatible design for providing beam mapping may be one in which each beam is defined with a reference angle. An example may be the center of a beam. Then for each candidate beam, its orientation may be specified relative to the reference beam / angle, and its beam width may be provided. In the following zero outage beam failure recovery mapping example, the ZeroOutage-BFR-Map may provide beam coverage in terms of beam-reference-orientation, beam-orientation, and beam-width parameters. This may be taken as an example and as other parameters for defining the area associated to the candidate beam. Below is an example pseudocode for a zero outage beam failure recovery (BFR) mapping.

[0162]

[0163]

[0164] The configuration may be further updated if all SSB beams are to have a common beamwidth and all CSI-RS beams are to have a common beamwidth. The beam angles, whether defined as start and end angles relative to a reference or as reference beam orientation angles defined relative to a reference, may be defined as azimuth and vertical angles relative to a reference direction. The reference direction may be defined in a global coordinate system (GCS) or a local coordinate system (LCS). In a GCS, the estimated azimuth angle may be measured relative to geographic north and be positive in the counterclockwise direction, while the estimated vertical angle is measured relative to the zenith and is positive in the horizontal direction. In an LCS, the estimated azimuth angle is measured relative to the x-axis of the LCS and is positive in the counterclockwise direction, while the estimated vertical angle is measured relative to the z-axis of the LCS and is positive in the xy plane direction.

[0165] Although the zero-outage BFR procedure may work in a standalone configuration, it may still run in parallel with the legacy BFR procedure. The WTRU may thus receive a configuration of a set of candidate beams with suitable mapping for zero-outage BFR and may simultaneously receive a set of candidate beams for the legacy BFR procedure.

[0166] In this section, unified configuration settings including zero outage BFR and traditional BFR may be discussed. When the network decides to configure BFR candidates for the WTRU, the configuration design may be unique, which may be used to provide a set of candidate beams for traditional BFR and a set of candidate beams for the proposed zero outage BFR. The two sets may have overlapping candidate beams. IEBeamFailureRecoveryConfig may be used to configure the WTRU with RACH resources and candidate beams for beam failure recovery in the event of beam failure detection. An example of a zero outage beam failure recovery configuration structure may be provided below. This information element may use traditional parameters such as rootSequenceIndex-BFR, rach-ConfigBFR, rsrp-ThreshoholdSSB, etc. ZeroOutage-BFR-SSB-Resource and ZeroOutage-BFR-CSI-RS-Resource may be key parameters for associating candidate SSB / CSI-RS beams to their corresponding active coverage areas through the parameter ZeroOutage-BFR-Map. In addition to the traditional BFR-SSB-Resource and BFR-CSI-RS-Resource, ZeroOutage-BFR-SSB-Resource and ZeroOutage-BFR-CSI-RS-Resource can also be used and both provide a relevant area for each SSB / CSI-RS beam. The following is an example pseudo code for the beam failure recovery configuration information element.

[0167]

[0168]

[0169] In this design, a single reference orientation may be provided for all beams, as opposed to previous designs where each candidate beam may be configured with its own reference orientation. Similar techniques may be applied in this unified design to enable beam-based references to be specified.

[0170] Both separate zero-outage BFR configurations and unified BFR configurations may be defined for beams derived based on SSB or CSI-RS signals. Similarly, specific metrics (e.g., RSRP, RSRQ, and / or SINR, etc.) may be used to define conditions for these measurement objects using SSB or CSI-RS. For ultra-large-scale MIMO, there may potentially be new reference symbol structures that are more suitable for generating thousands of beams. These beams and associated reference symbols may be sent from the network in a hierarchical manner. There may be multiple layers of such beams of varying widths. These ultra-large-scale and holographic MIMO beams may be appropriately associated with appropriate reference symbols of potential new designs to provide zero-outage BFR configurations to the WTRU. These new reference symbols may also follow the design and transmission of such holographic beams. New measurement metrics may also be designed that capture the quality of a given beam in a more accurate and rapid manner. For a hierarchical design, the quality of the beam may be derived based on measurements of potential overlapping / superimposed beams. Beam failure and restoration conditions and thresholds may be suitably defined and configured using existing reference symbols or new reference symbols defined for emerging networks with a large number of beams, using existing or new metrics to be evaluated in view of these reference symbols and measurements, and suitable thresholds.

[0171] Zero-outage BFR, which configures a limited snapshot of neighboring beams to the WTRU through network sharing, may not be limited to scenarios where the WTRU / device is undergoing rotational motion. In fact, the proposal is fully applicable to rotational motion, translational motion, a mobile blocker blocking a beam / link, or beam / link failures due to other reasons, or any combination of the aforementioned mobility / blocking events. Fig.14 A WTRU device is shown inside a vehicle traveling on a road. This figure shows 3 TRPs each providing 3 beams to cover a portion of a road segment. The network may provide the WTRU with a beam configuration in case the WTRU cannot find a beam that it is not yet in coverage. To cover translational motion, the beam recovery configuration may include beam identifiers that are tied to the location they are serving. This information may be communicated to the WTRU using the WTRU's location and relative distance or in terms of absolute positions for the beams, which may be for each beam based on an appropriate reference position and beam width or operating cone.

[0172] SSB and CSI-RS beams can individually indicate an active area that can indicate a reference direction for specifying an angular span. In addition to the angular span, suitable coordinates can also be used to specify the translation coverage area. These coordinates can be, for example, longitude and latitude obtained by a GPS system. Suitable quantization can be applied to the indicated values ​​to avoid excessive overhead. The following unified zero-outage BFR mapping for SSB and CSI-RS beam examples can provide ZeroOutage-BFR-SSB-Resource and ZeroOutage-BFR-CSI-RS-Resource. Both ZeroOutage-BFR-Map and ZeroOutage-BFR-Resource provide a configuration structure for the active beam area by defining the parameter ZeroOutage-BFR-Map of the active area through a set of parameters. In this example, ZeroOutage-BFR-Map can define the active beam area through beam-reference-orientation, beam-start-angle, beam-end-angle, beam-reference-position, and beam-active-span. Below is an example pseudocode for unified zero-outage BFR mapping for SSB and CSI-RS beams.

[0173]

[0174] In the ZeroOutage-BFR-Mapping parameter structure, each candidate beam may additionally have the Reference-Position and Active-Span indicated. This may enable a given beam to be mapped to a specific geographic region with a specific angular span. This configuration may be appropriately used in many real-world scenarios that we encounter today and that stand out in problem formulations as a combination of high mobility, large numbers of beams, and limited discovery / feedback opportunities. Further refinement of the beam geographic coordinates and regions may be added in the Zero-Outage-BFR-Mapping structure to make it granular to the appropriate degree and have coverage of the desired geospatial coordinates.

[0175]

[0063] In the proposed implementation where the gNB configures the WTRU with candidate beams for the beam recovery procedure, different suitable reference points may be used to indicate the angular span of the candidate beams and to indicate the active translation region. To indicate the angular span of the candidate beams, the reference direction may be considered as the serving beam of the gNB. In another design, the reference direction may be considered as one of the directions from the cardinal directions. The configuration of the reference beam may be given in terms of the TCI state including the reference DL / UL beam or the associated RS.

[0176] To indicate the active translation area for a candidate beam, this area may be indicated in terms of absolute GPS coordinates. In different designs, the active translation area may be specified relative to a suitable reference location / position. This reference may be the location of the gNB, which may also be indicated as part of the configuration. The current location of the WTRU may be considered as a reference point. In different designs, when different beams originate from different TRPs, the network may configure the location of the source TRP along with the candidate beams. With this information, the WTRU may determine the strongest beam assuming line of sight which may be reasonable for communications at high frequencies.

[0177] Most of the steps of the proposed implementation involving providing WTRU assistance information, network configuration of candidate beams, and WTRU evaluation of the configured beams using network provided geographic coordinates may remain valid for the beam failure recovery procedure triggered after beam failure detection for SpCell or SCell. Since the WTRU does not need to send RACH for BFR on SCell, the zero-interruption BFR configuration provided for SCell may not include the RACH preamble and related parameters. From a WTRU action perspective, once the WTRU identifies the most suitable candidate beam for BFR, the WTRU may prepare a set of confirmed candidate beams and prepare a MAC CE (BFR or truncated BFR). For the beam recovery procedure on SpCell, the WTRU may send RACH according to the configured parameters and may send MAC CE as part of the RACH transmission.

[0178] For the beam recovery procedure on the SCell, the WTRU may send a BFR or a truncated BFR MAC CE to the network on a specific cell that is the primary cell of the associated cell group. Even this procedure may achieve significant latency benefits from the WTRU being able to quickly determine the best beam, since the proposed mapping of candidate beams is provided with respect to appropriate geographical coordinates and can potentially be combined with radio measurements to make the solution richer and more granular using information from local sensors. The zero-outage BFR configuration for the SCell may be specified similar to the configuration changes proposed earlier for the SpCell. In the normal design of the BFR configuration for the SCell, the RACH related details may not be provided. However, in the proposed method, the SCell may be configured for RACH transmission and, if so, the BFR configuration for such SCell may include the relevant RACH parameters.

[0179] In order to make BFR faster for both SpCell and SCell, when the WTRU is configured with zero outage beam failure recovery candidates, beam failure detection may be declared earlier or with a larger threshold compared to the legacy beam failure detection parameters. For this purpose, two sets of thresholds may be indicated for beam failure detection. One set of thresholds may be the legacy beam failure detection thresholds, and the new, stricter thresholds may only apply when the WTRU has a zero outage configuration available. Beyond the thresholds, new conditions or new events may be defined as being more relevant for zero outage BFR.

[0180] An exemplary embodiment of a procedure for a WTRU to have zero outage when undergoing a beam failure recovery procedure may include the following steps. These steps may include: (1) The WTRU transmits zero outage assistance information to the gNB, as shown in 1204 and 1304; (2) The gNB prepares an appropriate unified zero outage BFR configuration based on the assistance information received from the WTRU and its network deployment of TRP, cells and beams, and sends this configuration to the WTRU; (3) The WTRU receives the configuration for zero outage BFR from the gNB, as shown in 1206 and 1306; (4) When the WTRU detects a beam failure (the configured reference signal of the serving beam drops below the configured threshold or the condition of BFD is fulfilled), the WTRU starts the beam failure recovery procedure; (5) The WTRU obtains the beam failure information from the local sensor (GNB), potentially in combination with radio measurement results. (6) The WTRU evaluates the changes in local sensor data and configured conditions to determine device mobility or external mobility according to the configuration used to determine device mobility or external mobility, as shown in 1210 and 1310; (7) The WTRU selects the highest priority beam among the determined candidates, as shown in 1214, 1224, 1314 and 1324; (8) The WTRU activates the antenna panel associated with the selected BFR candidate; (9) The WTRU measures the quality of the selected BFR candidate beam using the configured measurement signal and the configured threshold, as shown in 1216, 1226, 1316 and 1326. The zero-outage assistance information transmitted to the gNB may include radio-measurement-quantity-based-data, non-radio-measurement-quantity-based-data and / or WTRU-capability-and-Implementation-details. The configuration for zero outage BFR received from the gNB may include a single configuration covering device mobility and external mobility. The single configuration covering device mobility and external mobility may include parameters. These parameters may include, for example, a set of candidate beams, candidate beams associated to appropriate SSBs, CSI-RS, or newly designed reference signals, RACH parameters associated to each candidate beam, a mapping of candidate beams to appropriate geographic coordinates (location, position, orientation) to accommodate device mobility and external mobility, and / or an indication of priority for candidate beams when multiple candidate beams may have at least partial overlap for certain geographic coordinates. When the WTRU determines that there is device mobility, the WTRU may use its determined geographic coordinates (location / location and orientation, etc.) and radio measurement results from the configured mapping table to determine the candidate beam as a recovery candidate.When the WTRU determines that there is external mobility, the WTRU may use its determined geographic coordinates (position / location and orientation, etc.) from the configured mapping table to determine the candidate beams as recovery candidates. Determining the candidate beams may include removing the beam on which the beam failure detection occurred from the candidate set in the case of external mobility.

[0181] Beam failure recovery may be SpCell specific. When the selected candidate passes the quality criteria, the WTRU may extract its associated RACH configuration parameters. The WTRU may use the derived RACH parameters to send RACH for the BFR candidate. The WTRU may prepare and send a BFR MAC-CE to the network providing information on suitable candidate beams.

[0182] Beam failure recovery may be SCell specific. When the selected candidate passes the quality criteria, the WTRU may prepare a BFR MAC-CE. The WTRU may send a BFR MAC-CE to the network.

[0183] An exemplary embodiment of a procedure for a WTRU to have zero outage when undergoing a beam failure recovery procedure may include the following steps. These actions may include: (1) The WTRU transmits zero outage assistance information to the gNB; (2) The gNB prepares a plurality of suitable zero outage BFR configurations based on the assistance information received from the WTRU, the WTRU profile and its TRP, the network deployment of cells and beams, and sends such configurations to the WTRU; (3) The WTRU receives a set of configurations for zero outage BFR from the gNB; (4) When the WTRU detects a beam failure (the configured reference signal of the serving beam drops below a configured threshold or the condition of BFD is fulfilled), the WTRU starts the beam failure recovery procedure. process; (5) the WTRU obtains information from local sensors (GPS, accelerometer, gyroscope, etc.), potentially in combination with radio measurement results; (6) the WTRU evaluates changes in local sensor data and configured conditions to determine device mobility or external mobility in accordance with the configuration used to determine device mobility or external mobility; (7) the WTRU selects the highest priority beam among the determined candidates; (8) the WTRU activates the antenna panel associated with the selected BFR candidate; (9) the WTRU measures the quality of the selected BFR candidate beam using the configured measurement signal and the configured threshold. The zero-outage assistance information to the gNB may include radio-measurement-quantity-based-data, non-radio-measurement-quantity-based-data and / or WTRU-capability-and-Implementation-details. The configuration set for zero-outage BFR received from the gNB may include two configurations for device mobility and external mobility. Each configuration of device mobility and external mobility may include parameters. These parameters may include, for example, a set of candidate beams / TRPs, candidate beams associated to appropriate SSBs, CSI-RS, or newly designed reference signals, RACH parameters associated to each candidate beam, mapping of candidate TRPs / beams to locations / positions, orientations for device mobility, mapping of candidate TRPs / beams for external mobility, and / or an indication of the priority of candidate beams when multiple candidate beams may have at least partial overlap for certain geographic coordinates. If the WTRU determines device mobility, the WTRU may select a device mobility BFR configuration. The WTRU may use its determined geographic coordinates (location / location and orientation, etc.) and radio measurements from the selected configuration mapping table to determine the candidate beams as recovery candidates. If the WTRU determines external mobility, the WTRU may select an external mobility BFR configuration. The WTRU may use its determined geographic coordinates (location / location and orientation, etc.) from the selected configuration mapping table to determine the candidate beams as recovery candidates.Determining the candidate beams may include removing the beam on which the beam failure detection occurred from the candidate set in case of external mobility.

[0184] Beam failure recovery may be SpCell specific. When the selected candidate passes the quality criteria, the WTRU may extract its associated RACH configuration parameters. The WTRU may use the derived RACH parameters to send RACH for the BFR candidate. The WTRU may prepare and send a BFR MAC-CE to the network providing information on suitable candidate beams.

[0185] Beam failure recovery may be SCell specific. When the selected candidate passes the quality criteria, the WTRU may prepare a BFR MAC-CE. The WTRU may send a BFR MAC-CE to the network.

[0186] In an example embodiment, a zero-interruption conditional handover may be performed. 3GPP has defined a conditional handover (CHO) procedure in which the WTRU is provided with the configuration of a candidate cell for CHO under execution conditions. When the execution conditions for the candidate CHO cell are met, the WTRU may start the handover procedure with the candidate cell. If the current serving cell experiences a rapid failure, this process may provide a shield against traditional handover issues. The WTRU may be unable to complete the handover signaling exchange with the source cell, resulting in a handover failure. For one example, a traditional handover failure may occur when the WTRU is providing measurement results to the source cell. For another example, a traditional handover failure may occur when the source cell is providing a handover configuration to the WTRU. If a traditional handover failure occurs, the WTRU may need to perform both RRC connection reestablishment or final cell selection, resulting in delays and interruptions that far exceed the QoS requirements for future applications.

[0187] The proposed solution for zero-disruption conditional handover may be trying to achieve predictive mobility. Since the cellular network is a planned network, the network may know exactly the deployment of its cells and the beams within those cells. What the network may not know is how a particular WTRU moves from one cell / beam to another. In fact, this information is generally not even known to the WTRU itself. In general, the WTRU may not have information about the network deployment in terms of cells and beams and the geographical areas where these cells / beams are active. Instead, the WTRU may be equipped with many local sensors and may have additional interfaces and connections to other RATs / devices to track its movement and determine its new geographical coordinates and orientation in a very fast manner.

[0188] The proposed method may combine (i) knowledge of the network deployment of cells / beams and (ii) the ability of the WTRU to track its movement and determine an updated geographic location / position and orientation as a goal. The network shares a suitable limited portion of its deployment related to this WTRU based on the assistance information received from the WTRU. The shared portion of the network deployment may include neighboring cells and related beams that provide mappings of these (cells, beams) pairs to suitable geographic coordinates. The configuration may include execution conditions for performing conditional switching to the configured (cell, beam) pairs. In the event of degradation of the quality of the service link, the WTRU may use information from local sensors and interfaces to extract its current geographic coordinates and orientation. Using these parameters, the WTRU may determine suitable conditional switching candidate (cell, beam) pairs from the configuration provided by the network. The configuration parameters provide quality criteria and execution conditions for candidate (cell, beam) pairs and their RACH configurations. If the execution conditions are fulfilled, the WTRU may initiate a conditional switching to the candidate (cell, beam) pair. The deterministic derivation of suitable candidates (cells, beams) can be paired with the updated geographic coordinates, resulting in WTRU mobility management with seamless handover and minimal interruption.

[0189] The auxiliary information from the WTRU may be broadly classified into two groups referred to as measurement-based data and non-measurement-based data. One group of auxiliary information may include all information that can be estimated, measured, determined with or without post-processing of signals received from the radio interface for which mobility is being considered. This group may be referred to as measurement-based data. Measurement-based data may include receiving, measuring, and processing reference signals on the physical layer, MAC information elements, RRC messages received from the network, or information received at higher layers. The second group of auxiliary information may include all information that is not extracted from network signaling. This group may be referred to as non-measurement-based data. A subgroup of the non-measurement-based data may include the WTRU's ability to cover its antenna panels and implementation details, the corresponding fields of view of those panels, transceiver and power characteristics, switching delays, simultaneous operations for panels, etc. The second subgroup of non-measurement-based data may cover all information extracted or measured by local sensors and interfaces other than the radio interface for which mobility is being considered. Examples of local sensors may include positioning sensors, gyroscopes, accelerometers, etc. Interfaces other than the radio interface considered may be wired interfaces like Ethernet, wireless interfaces like Bluetooth, WIFI, or any other proprietary wired or wireless interface. Another subset of the non-measurement based data may include mobility metrics and configurable triggers. Examples of mobility metrics may be speed, rate, and history of mobility, etc. Relevant configurable triggers that are helpful for mobility management and provide suitable configuration may come from situational or contextual information. For example, a vehicle device (or a device inside) may start its trajectory to a destination, where both the start and the trajectory may be very important from a configuration perspective. Another example may be starting an online game from an AR / VR device that potentially includes a user profile that incorporates or provides user behavior on a rotational basis during the game. Such parameters may also be updated by the WTRU when a certain BFR configuration has been received from the gNB. The gNB may also update the BFR configuration when updated assistance information or other factors are received from the WTRU.

[0190] The auxiliary information may be classified in different groups and subgroups. The method proposed here may target conditional switching with zero interruption. An overview of the steps of this method may include the following steps.

[0191] The first step may include the WTRU providing assistance information about its location / location / panel / FoV / application-QoS to the gNB. This assistance information may incorporate and simplify potential information from advanced sensors used by the WTRU and provided to the gNB. Examples of such information may be information generated by positioning sensors, gyroscopes, and accelerometers. The WTRU may update its assistance information for certain parameters at least under certain conditions.

[0192] The second step may include the gNB providing a zero-outage conditional handover configuration in response to the WTRU assistance information. This configuration may be based on the network deployment of cells, TRPs, beams, and the assistance information provided by the WTRU. The configuration preparation may take into account any historical data about WTRU parameters, application usage, WTRU subscription status, etc. The configuration preparation may use artificial intelligence and machine learning algorithms to use all network and WTRU data to prepare a configuration suitable for the WTRU in a predictive manner.

[0193] The third step may include a zero-interruption conditional handover configuration including a set of candidate cells. For each cell, a relevant beam index may be provided. For each (cell, beam) pair, a mapping of the pair to a suitable activity area (location / location, angular span, WTRU panel) may be provided, where this cell / beam pair is used for conditional handover. Execution conditions may also be provided as part of the configuration for each (cell, beam) pair. When multiple pairs are indicated for a given location and angular span, a priority for the (cell, beam) pair may be provided as part of the configuration. For each candidate (cell, beam) pair, the configuration may provide a suitable RACH preamble and other RAC configuration parameters.

[0194] The fourth step may include the WTRU extracting information from its local sensors after a mobility event (caused by device mobility or mobility in the environment) that resulted in impaired link quality. The WTRU may combine appropriate information elements from measurement-based data and non-measurement-based data. Based on its estimated geographic coordinates and orientation, the WTRU may derive the highest priority (cell, beam) pair from the mapping of the network configuration mapped to its estimated geographic coordinates.

[0195] The fifth step may include the WTRU evaluating the execution conditions for the determined (cell, beam) pair according to the configuration provided by the network. If the evaluation result is fulfilled, the WTRU may use the configured RACH parameters to perform conditional switching to the determined candidate (cell, beam) pair.

[0196] Details of procedures for zero-outage conditional switching are discussed. Due to very large-scale MIMO beam deployments, higher mobility, special conditions in the nature of object placement and obstructions on the ground, a limited number of antennas, antenna panels, transceivers, or strict requirements on power consumption, the WTRU may have limited discovery of neighboring cells / gNBs around it. This may result in limited or no neighboring cells being discovered and reported to the network by the WTRU. With traditional switching and conditional switching procedures where the network configuration is typically based on WTRU reports, configuration from the network and mobility aggravated by rotation may cause the WTRU to land in the angular coverage of the beam of a new gNB that cannot be discovered and reported to the network. The most suitable (cell, beam) may change faster for future deployments of very large-scale MIMO beams, and if each such change requires network configuration and exchange with the network, the resulting overhead may be excessive. The proposed zero-outage conditional switching provides a mechanism for avoiding frequent and larger outages for such scenarios.

[0197] In an example embodiment, the WTRU may provide assistance information to the gNB. This information may include measurement-based data and non-measurement-based data as detailed earlier. The base station may indicate to the WTRU a set of gNBs and their suitable coverage areas in the vicinity of the actual location of the WTRU. The suitable coverage area may include indications in terms of location and orientation. The location may cover the translational mobility that the WTRU is capable of. The translational mobility may be associated with each configured beam belonging to a neighboring cell / gNB. The translational mobility indication may refer to the actual location of the WTRU. Another approach may be to provide a translational mobility indication in terms of absolute location. The absolute location may be the GPS coordinates associated with each beam of each configured cell / gNB.

[0198] The directional indication may cover rotational movement of the WTRU, which may occur with or without translational movement. Directional indications may be provided for one or more beams from each configured gNB. The directional indication may be in the form of angular coverage relative to a suitable reference direction. The reference beam indication may be part of the configuration. The reference beam may be defined as an SSB beam or a CSI-RS beam. Additionally, the reference beam may be the actual beam that the network is using to serve the WTRU. Instead of a reference beam, other methods may be used to specify a reference direction (e.g., geographic north or some other reference understandable to both the network and the WTRU). In one example, directional information may be given relative to one or more configured TCI states, where the TCI state may contain QCL reference information for a DL or UL beam / RS of a cell.

[0199] For each (cell, beam) pair in the configured conditional handover set, in addition to its angular span around the WTRU, the network may also provide relevant parameters to trigger the conditional handover. These parameters may include the contention-free RACH preamble within the beam. This may include RACH parameters such as RACH preamble sequence identity, RACH duration, power ramp parameters, parameters related to RACH opportunities associated with the indicated beam, etc.

[0200] In a compatible design solution, the configuration may also include conditions under which the configuration remains valid. The configuration may have a timer and the validity may expire when this timer expires. Another configuration release condition may be associated with mobility. For example, if the configured device moves more than a configured threshold away from its last known position / location, it may release the configuration. For example, the WTRU may release the configuration if it has just moved out of its current zone. In another example, the configuration may be valid in the current zone and a directly adjacent zone with overlapping boundaries. In this case, if the WTRU moves out of the directly adjacent zone, it may release the configuration. Another example where the configuration release condition may be associated with the timing advance value of the device (e.g., with the serving gNB). For example, if the device moves and the change in timing advance is above a configured threshold, the device may be configured to release the currently active configuration. More generally, any suitable combination of parameters from auxiliary information may be used to define validity conditions and release conditions.

[0201] In another solution, one or more configurations may be given to a device. A mapping / association of configurations to regions, locations, or timing advance values / ranges may be given to a device. The device may select a configuration based on tracking of relevant metrics (region, location, or timing advance, etc.).

[0202] For systems based on very large-scale MIMO with the ability to deploy thousands of beams per TRP, the network deployment of beams may follow certain rules in order to contain the signaling overhead. The rules may be provided to the WTRU in a compact form. In one example, the beam deployment from the TRP may follow a pattern in the azimuth and elevation dimensions. A set of patterns may be known in table form or through a formula. The network may select a suitable pattern for its deployment based on its requirements in a given geographic area. For such cell and beam deployments, the network may provide the WTRU with a compact form of the deployment pattern as part of the zero-interruption conditional switching configuration. The configuration may include the location of the TRP in appropriate coordinates for the candidate (cell, beam) pair. A WTRU receiving such a configuration may determine the nearest TRP for any location relevant for each candidate (cell, beam) pair, and then determine a suitable candidate (cell, beam) that matches its updated geographic coordinates.

[0203] exist Fig.15An example configuration for a WTRU rotation scenario is shown in Figure 1 for a WTRU communicating with gNB 1. This figure may show the configuration including an indication of the reference direction in the current beam case and the neighboring cells / beams with their spans. In this example figure, the beam from gNB 2 may be configured with its span marked relative to the reference (beam) direction as the starting angle (β2s) and the ending angle (β2e). Similarly, the figure may show the starting angle and the ending angle of an example beam from gNB 3 as β3s and β3e. For each configured candidate (cell, beam) pair, the gNB provides RACH related details to allow contention-free RACH access (CFRA) within that (cell, beam) pair.

[0204] Fig.16 Another example scenario may be shown where the WTRU is configured by the network with multiple CHO candidates to combat both translational and rotational motion. In this case, the WTRU may be configured with a CHO configuration with the WTRU's location / position and orientation and a mapping to candidate CHO cells from different gNBs such that the WTRU uses mobility information from its local sensors to determine the appropriate beam / gNB to attach to. The location / position and angular span may be provided with reference to the WTRU location and orientation.

[0205] Fig.17 An exemplary scenario may be shown where the WTRU is moving on a road in a car. This WTRU may face a situation where it crosses beams from a single TRP, from one TRP to a beam of a neighboring TRP controlled by the same control unit (CU), and moves from one beam of a given TRP to beams from different TRPs under different CUs. The figure may show scenarios where beam / cell switching occurs as a result of translational motion, rotation, or a combination. The WTRU may be provided with a zero-outage beam failure recovery configuration and a zero-outage conditional handover configuration. These configurations allow the target WTRU to monitor its mobility state through information obtained from its local sensors, potentially confirmed by over-the-air measurements, and perform zero-outage beam recovery and zero-outage CHO to avoid any outages as it may be moving very quickly and traversing beams and cells.

[0206] If the WTRU experiences impaired link quality, the WTRU may extract information from local sensors. The WTRU may combine this information with other radio measurements. Translational movement information may come from a local GPS receiver, for example. Rotational movement may come from a gyroscope or other component. The WTRU may calculate its new geographic coordinates and orientation. The new geographic coordinates and orientation may be used to find suitable candidate (cell, beam) pairs from the (cell, beam) pairs and the network provided mapping of geographic coordinates and orientation. This allows the WTRU to know exactly which beam of the suitable cell from the suitable gNB should have line-of-sight connection relative to its updated coordinates. As a result, the WTRU may not need to perform a blind cell search to discover which beams of which cells will be active and suitable after experiencing a mobility event.

[0207] After having derived a suitable (cell, beam) pair from the network provided configuration, the WTRU may evaluate the CHO condition using this target candidate pair. If the CHO triggering condition is met, the WTRU may transmit a contention-free RACH on the configured RACH resources provided as part of the determined candidate (cell, beam) pair using the configured RACH parameters, as shown in 1818 and 1828.

[0208] Fig.18 An example flow diagram is depicted for a zero-outage conditional handover. For a WTRU in the RRC_CONNECTED state (1802), the WTRU may transmit advanced assistance information to the network / gNB (1804). This information from the WTRU may include information from local sensors (e.g., position sensors, gyroscopes, accelerometers, etc.). Additional groups and constituent elements for WTRU assistance information were discussed earlier.

[0209] Based on the WTRU assistance information, TRP, network deployment of cells and beams, WTRU profiles for services and mobility, QoS requirements for the services / applications the WTRU is using, the network may provide the WTRU with a suitable configuration for zero-disruption CHO (1806). This configuration may include candidate cells and beams, and a suitable mapping of these candidate (cell, beam) pairs to suitable geographic coordinates and orientations. The configuration may also include parameters and thresholds for the WTRU to derive its zone / location / position and span in order to determine the appropriate (cell, beam) pair from the mapping table. The configuration may provide two sets of sub-configurations, one set of sub-configurations for handling device mobility where the device is experiencing translational and rotational movement, and another set of sub-configurations focused on interrupting external mobility that is a result of the environment rather than direct device mobility. As an example, when a serving cell is degraded or experiences a failure, the external mobility generated by the mobility blocker may provide a (cell, beam) pair that can provide coverage to a target device whose location / position is known at the network. This step may require the WTRU / device to switch and activate to a different panel where the gNB may provide indications as part of the configuration. This indication is in turn based on the fact that the WTRU may provide its antenna panel implementation and capabilities as well as a detailed feature set as part of its assistance information.

[0210] In a compatible approach, the network may provide a set of CHO configurations to the WTRU. The network may provide associations of these configurations to different appropriate criteria. These may include, but are not limited to, WTRU active applications, QoS such as different reliability requirements, different power consumption targets at the WTRU, WTRU active service subscription levels, etc. When the WTRU is experiencing a link failure or impaired link quality, the WTRU may use an appropriate configuration based on the current situation as per the configured criteria. As described earlier, multiple configurations may be associated to different physical parameters (e.g., external or device mobility), different service reliability targets (one configuration when higher reliability is required and one configuration for lower reliability), different subscription levels (one configuration when the WTRU is using paid content versus one configuration for non-paid content), etc.

[0211] When the WTRU faces impaired link quality according to the configured quality threshold, the WTRU may extract information from its local sensors (1808). The sensor information may be combined with measurements performed using new or existing reference signals received from the network. An example may be to combine them with measurements performed using downlink positioning reference signals. The WTRU may determine the nature of the mobility (1810). The WTRU may use this information to select a suitable (cell, beam) candidate pair from the device mobility (1812) or the external mobility configuration (1822). The WTRU may map the information from the local sensors to a suitable format for location / area / orientation according to the selected suitable configuration and then derive its location / orientation. Using this location / orientation, the WTRU may determine a suitable (cell, beam) pair from the configured mapping.

[0212] The entries in the mapping table may provide multiple candidate (cell, beam) pairs for a given location / orientation. In this case, the network configuration may provide a priority order for the candidate (cell, beam) pairs. The WTRU may select the most appropriate candidate for external mobility (1824) or device mobility (1814). In a compatible design, the priority for multiple pairs for a given location and angular span may be left to the WTRU implementation. The WTRU may then evaluate the configured CHO execution conditions (1816) as configured. The WTRU may determine the RACH configuration (1818) for the determined CHO candidate and execute CHO (1820) to the determined target. The execution conditions may be specified by appropriate configuration of conditional event A3 and conditional event A5. Conditional event A3 may be defined as the situation when a candidate CHO cell (with a suitable beam) becomes better offset than the current SpCell, the primary cell of the primary cell group, or the primary cell of the secondary cell group. Conditional event A5 may be defined with two absolute conditions. One condition may be defined for SpCell to become worse than a configured threshold, and a second condition may be specified for CHO candidates to become better than another configured threshold. For target use cases spanning very large-scale MIMO beams with various deployment possibilities including layered and hierarchical architectures, new reference signals may be designed to appropriately and quickly identify, detect and measure such beams. These reference signals may then be used to identify (cell, beam) pairs and provided as part of the network configuration. Quality criteria and CHO execution conditions (conditions A3 / A5 or newly designed) may then be specified in terms of the new reference signals.

[0213] In a compatible design for allowing zero-outage conditional handover, the configurations for candidate (cell, beam) pairs may be provided as a unified configuration, such as Fig.19 Depicted. Fig.19Depicted is another example flow diagram for zero-outage conditional handover.In this unified configuration, all candidates and their priorities may be provided with their mapping to appropriate geographic coordinates, orientation, and association with other parameters that the WTRU may extract and use to determine the appropriate CHO candidate. Fig.19 A flow diagram is shown for zero-disruption conditional switching with key changes from the previous figure that provides network configuration (1906) for CHO candidates in a unified manner, thereby covering candidates targeting external mobility and device mobility.

[0214] For a WTRU in the RRC_CONNECTED state (1902), the WTRU may transmit advanced assistance information to the network / gNB (1904). Once the WTRU is experiencing a link failure situation or the quality of the serving link is decreasing below a configured threshold, the WTRU may obtain information from its local sensors (1908) to determine whether the link failure occurred due to device mobility or external mobility (1910). This information is combined with information from other sensors; the WTRU may select a suitable CHO configuration for the external mobility situation (1922) and a suitable CHO configuration for the device mobility situation (1912). In the case of multiple candidate configurations, the WTRU may select the most suitable candidate for external mobility (1924) or the most suitable candidate for device mobility (1914). In order to initiate a conditional handover to the most suitable CHO candidate, the WTRU may need to activate different antenna panels according to the selected configuration. In the case where the appropriate antenna (panel) is activated, the WTRU may evaluate the execution conditions for the selected CHO candidate (1916). The CHO execution conditions may be configured in terms of RSRP, RSRQ or SINR using appropriate indicated measurement objects. In addition, the CHO configuration may provide the same or different execution conditions for different CHO candidates. If the selected CHO candidate satisfies the execution conditions, the WTRU may select a RACH configuration associated to the selected (cell, beam) candidate (1918) and send a RACH as part of the CHO initiation (1920). This may essentially trigger a fast attach procedure to the CHO candidate.

[0215] To achieve zero-outage CHO, the network configuration may include suitable CHO candidate (cell, beam) pairs. A mapping of these CHO candidates to suitable geographic coordinates and orientations may also be provided. In an example embodiment, the geographic coordinates (such as location / position) and orientation / angular span coordinates of the (cell, beam) pair may be provided relative to the WTRU location and a reference direction. The reference direction may be relative to one of the cardinal directions, or it may be specified relative to the current serving beam or another suitable reference. With this design, CHO candidates (neighboring cells) may be provided with distance and orientation parameters that allow the WTRU to determine that it can appropriately attach to the active area of ​​these candidates.

[0216] In a compatible design for zero-outage CHO, the configuration of candidate CHO (cell, beam) pairs may provide the locations of the network nodes (DU, TRP, gNB) that transmit these candidates. The configuration may also include the orientation / angular span of the beams associated to these nodes using appropriate coordinates and references. A WTRU that knows the locations / positions of a set of nodes that transmit candidate CHO cells may determine the strongest (closest) node that knows its own location / position available through local sensors. In some settings, the data of the local sensors may be augmented by appropriate radio measurements. In order to cover special geographical settings or known shadows, the network may provide a priority to be used in addition to the nearest node selection or an appropriate offset to be used when calculating the nearest node. The orientation for the (cell, beam) pair may be indicated relative to an appropriate reference that is understandable at the WTRU. The orientation reference may be relative to a global or local coordinate system. In another design for providing an orientation indication, the reference direction used for the orientation may itself be part of the configuration. For example, the network may indicate that the reference direction is due north (or a different due north direction) and may provide all angular spans of the beam relative to this reference direction. In a different example, the reference direction may be relative to a serving beam of a configured serving node by which the network provides zero-out CHO. The reference direction may be updated by the network if necessary.

[0217] For legacy CHO, 3GPP may use IECondReconfigToAddModList which provides a list of conditional reconfigurations to be added or modified for each entry, condReconfigId, and the associated condExecutionCond and condRRCReconfig. This may allow the network to add cells as CHO candidates. For the proposed zero-outage CHO solution, a more feature-rich information element (IE) ZeroOutageCondReconfigToAddModList may be specified which provides the WTRU with zero-outage configurations for candidate (cell, beam) pairs by providing an additional mapping of candidate (cell, beam) pairs to geographic coordinates and orientation in a suitable format. ZeroOutageCondReconfigToAddMod may provide zero-outage CHO configuration candidates to be added or modified according to the corresponding execution conditions. Below is an example pseudocode for zero-outage conditional handover configuration.

[0218]

[0219] In one design for implementing zero outage CHO, the beams associated to each CHO cell and their mapping to appropriate geographic coordinates and orientations may be added in RRCReconfiguration. This may be implemented by adding a new information element as part of RRCConfiguration that provides the mapping of cell beams to geographic coordinates. Similar information elements may be added as part of the zero outage beam failover configuration, i.e., ZeroOutagePRACH-ResourceDedicatedBFR, ZeroOutage-BFR-SSB-Resource, ZeroOutage-BFR-CSIRS-Resource, ZeroOutage-BFR-Mapping, etc. The network may choose which beams (SSB or CSI-RS based or based on new reference symbols used to identify such beams) as part of the configuration for each candidate CHO cell.

[0220] In a different but compatible design, the RRCReconfiguration may remain unchanged and the relevant beams associated to a given CHO candidate cell and the mapping for each zero outage CHO candidate (cell, beam) pair may be added in the ZeroOutageCondReconfigToAddMod IE using an appropriate structure that provides the beams for each candidate cell and the active area associated to each (cell, beam) pair. The example design below may add a structure zeroOutageCHOBeamList to the zero outage CHO configuration. This may provide the network with a mechanism for pre-configuring the WTRU with all appropriate (SSB and CSI-RS) beams for the candidate CHO cell. As part of this configuration, a ZeroOutage-CHO-BeamMapping may be configured for each configured beam for the candidate CHO cell. This may in turn provide a mapping of the configured beams of the configured CHO candidate to the appropriate geographic coordinates and orientation. In the configuration shown below, beams may be specified for each CHO candidate and RACH opportunity, and the PRACH preamble index may also be specified per beam. Configuration can be simplified by associating the RACH configuration to the cell level configuration, but the beam level configuration allows a quick determination at the network that the WTRU is using a given CHO (cell, beam) pair for CHO. Most of the parameters in the following example configurations may have been described earlier in the context of zero outage beam failover configuration. Below is an example pseudo code for zero outage conditional reconfiguration for adding / modifying list elements.

[0221]

[0222]

[0223] In this example configuration design, CHO candidate cells can be defined, and for each CHO cell, a beam can be indicated using a mapping to geographic coordinates and orientation, effectively providing a mapping of each (cell, beam) pair to geographic coordinates and orientation. In a different approach, the entire design can be turned into (cell, beam) candidate pairs.

[0224] An exemplary embodiment of a procedure for specifying zero outage for a WTRU may undergo a conditional handover. The conditional handover may include: (1) the WTRU transmits zero outage assistance information to the gNB, as shown in 1804 and 1904; (2) the gNB prepares a set of appropriate zero outage CHO configurations based on the WTRU assistance information, the WTRU profile, and the network deployment / configuration and sends the set of configurations to the WTRU; (3) the WTRU receives the zero outage CHO configurations from the gNB, as shown in 1806 and 1906; (4) when the WTRU is experiencing a condition where the link quality is impaired (the serving cell quality is below a configured threshold), the WTRU starts the zero outage conditional handover process; (5) the WTRU obtains information from local sensors (GPS, accelerometer, gyroscope, etc.), potentially in combination with radio measurements, as shown in 1808 and 1908; (6) the WTRU evaluates the local sensor data and the configured conditions in to determine device mobility or external mobility in accordance with the configuration for determining device mobility or external mobility, as shown in 1810, 1812, 1822, 1910, 1912 and 1922; (7) the WTRU selects the highest priority CHO candidate (cell, beam) among the determined candidates, as shown in 1814, 1914, 1824 and 1924; (8) the WTRU activates the antenna panel associated with the selected CHO candidate; (9) the WTRU evaluates the configured execution conditions for the target CHO candidate, as shown in 1816, 1826, 1916 and 1926; and (10) if the execution conditions are met, the WTRU performs conditional CHO to the CHO target cell on the target beam, as shown in 1820, 1830, 1920 and 1930. The zero-outage assistance information transmitted to the gNB may include radio-measurement-quantity-based-data, non-radio-measurement-quantity-based-data, and / or WTRU-capability-and-Implementation-details. The received zero-outage CHO configuration may include a set of configurations, each of which is indicated for a scenario / condition. Each configuration may include a set of CHO candidate (cell, beam) pairs, a mapping of each candidate (cell, beam) pair to geographic coordinates and orientation for device mobility and external mobility, and / or a priority of (cell, beam) pairs when multiple (cell, beam) pairs may have overlap over geographic region / orientation. If the WTRU determines device mobility, the WTRU may select a device mobility CHO configuration. The WTRU may use its determined geographic coordinates (location / location and orientation, etc.) and radio measurement results from the selected configuration mapping table to determine the candidate (cell, beam) pair as the selected candidate. If the WTRU determines external mobility, the WTRU may select an external mobility CHO configuration.The WTRU may use its determined geographic coordinates (position / location and orientation, etc.) from the selected configuration mapping table to determine the candidate (cell, beam) pair as the selected candidate.

[0225] Exemplary embodiments may also include (1) two sets of conditional switching configurations associated with device mobility and external mobility, (2) a set of CHO configurations indicated as being associated with QoS requirements of specific applications / services running at the WTRU device, (3) a set of CHO configurations indicated as being associated with WTRU power consumption requirements, (4) a set of CHO configurations indicated as being associated with WTRU active subscriptions, and / or (5) only one unified configuration provided to the WTRU.

[0226] This section may discuss procedures for a WTRU that have been jointly configured by the network for zero outage beam restoration and zero outage conditional handover. FIG. 20 shows an example flow chart for a WTRU provided by the network for zero outage BFR and CHO configurations. The WTRU may provide assistance information to the network. The network may use this assistance information and its known deployment of cells, beams, and locations of TRPs to configure the WTRU with appropriate configurations for both zero outage BFR and CHO. These configurations may include details as outlined in the previous sections.

[0227] If the link quality is degraded for the target WTRU, it may extract information from its measurements, interfaces and local sensors to determine its updated geographic coordinates and orientation. This may additionally use the radio measurements to make the estimate more accurate, robust and granular. With the determined updated coordinates and orientation, the WTRU may first check if there are any suitable zero-outage recovery beams. If it finds any suitable recovery beams, it may extract the relevant configured parameters and initiate a beam recovery procedure with the derived recovery beam.

[0228] This flowchart may show that beam restoration (if configured and possible) takes precedence over conditional switching. The reason may be that in the CHO case, the WTRU needs to update the cell configuration which may require configurable changes relative to the current active cell configuration and the WTRU has a higher impact on QoS compared to the beam restoration procedure. Although this flowchart shows beam restoration before finding a CHO candidate, a slight variation may be that both the BFR configuration and the CHO configuration are evaluated simultaneously relative to the WTRU's updated determined geographical coordinates and the WTRU takes the most suitable candidate from either the BFR configuration or the CHO configuration. The network configuration may also provide priorities for BFR candidates and CHO candidates which may be used by the WTRU to prioritize the appropriate subsequent process as BFR or CHO.

[0229] In this flow chart, if the WTRU does not find any suitable recovery beam, it may check if there is any suitable CHO configuration for the updated location. If the WTRU is configured with a CHO configuration that matches its determined coordinates, it may select a suitable (cell, beam) pair from its selected CHO configuration and initiate CHO execution if the execution conditions are fulfilled.

[0230] If there are multiple candidates specified in priority order, the WTRU may try the highest priority candidate first before trying the next highest priority candidate.Multiple candidates with priority indication may be provided for both BFR procedures and CHO procedures.

[0231] For scenarios where the zero-outage BFR and CHO procedures are not completed successfully (which may be the result of the WTRU not obtaining an affirmative response to its BFR recovery transmission, CHO conditions not being fulfilled, CHO execution failure, or missing CHO / BFR configuration for the WTRU coordinates), the WTRU may resort to traditional beam recovery and switching procedures and ultimately fall back to RRC re-establishment and cell selection procedures.

[0232] An exemplary embodiment of a procedure specified for having zero outage for a WTRU experiencing a bad radio situation resulting in a beam / link failure may include the following actions. The WTRU may be in RRC-Connected mode (2002). The actions may include: the WTRU transmits zero outage assistance information to the gNB (2004); the gNB prepares multiple configurations for zero outage BFR and zero outage CHO based on the WTRU assistance information, the WTRU profile, the applications / services running at the WTRU, the WTRU subscription level and its network knowledge of the deployment of cells, beams and transport nodes, the gNB sends a set of configurations to the WTRU, the WTRU receives zero outage BFR and CHO configurations from the gNB (2006); when the WTRU is experiencing impaired link quality (beam or cell quality is below a configured threshold), the WTRU may start a composite zero outage beam recovery and conditional handover procedure. The WTRU may obtain information from local sensors (GPS, accelerometer, gyroscope, etc.), potentially in conjunction with radio measurements (2008). The WTRU may evaluate changes in conditions of local sensors and configurations to determine device mobility or external mobility in accordance with the configuration for determining device / external mobility (2012). The WTRU may select a device / external mobility beam restoration configuration (2010, 2014). If the WTRU does not find any suitable beam restoration candidate corresponding to its geographic coordinates and orientation in the beam restoration configuration, the WTRU selects a suitable device / external mobility CHO configuration as shown in 2022, 2024, 2026, 2034, 2036, 2038, 2040 and 2042. If the WTRU does not find any suitable CHO candidate corresponding to its geographic coordinates and orientation in the zero-outage CHO configuration, the WTRU may fall back to legacy behavior for beam restoration and (conditional) switching (2024). The zero-outage assistance information transmitted to the gNB may include radio-measurement-quantity-based-data, non-radio-measurement-quantity-based-data and / or WTRU-capability-and-Implementation-details. The received zero-outage BFR and CHP configurations may include a set of two zero-outage BFR configurations and / or a set of two zero-outage CHO configurations. The set of two zero-outage BFR configurations may include one configuration associated with device mobility and another configuration associated with external mobility.Each of the sets of two zero-outage BFR configurations may include, for example, a set of candidate beams / TRPs, candidate beams associated to appropriate SSBs, CSI-RS, or newly designed reference signals, RACH parameters associated to each candidate beam, mapping of candidate TRPs / beams to locations / positions, orientations for device mobility, mapping of candidate TRPs / beams for external mobility, and / or an indication of the priority of candidate beams when multiple candidate beams may have at least partial overlap for certain geographic coordinates. A set of two zero-outage CHO configurations may include one configuration associated to device mobility and another configuration associated to external mobility. Each of the sets of two zero-outage CHO configurations may include a set of CHO candidate (cell, beam) pairs, mapping of each candidate (cell, beam) pair to geographic coordinates and orientations, and / or the priority of (cell, beam) pairs when multiple (cell, beam) pairs may have overlap over geographic regions / orientations.

[0233] The WTRU may select a device / external mobility beam restoration configuration which may include: (1) the WTRU uses its determined geographic coordinates (position / location and orientation, etc.) and radio measurement results from the selected configuration mapping table to determine a candidate beam as a restoration candidate; (2) the WTRU selects the highest priority beam among the determined candidates; (3) the WTRU activates the antenna panel associated with the selected BFR candidate; (4) the WTRU measures the quality of the selected BFR candidate beam using the configured measurement signal and the configured threshold; (5) when the selected candidate passes the quality criteria, the WTRU extracts its associated RACH configuration parameters; and / or (6) the WTRU sends a RACH for the BFR candidate using the derived RACH parameters. The WTRU prepares and sends a BFR MAC-CE to the network providing information about the appropriate candidate beams.

[0234] If the WTRU does not find any suitable beam restoration candidate corresponding to its geographic coordinates and orientation in the beam restoration configuration, the WTRU may select an appropriate device / external mobility CHO configuration. This may include: (1) the WTRU uses its determined geographic coordinates (location / position and orientation, etc.) and radio measurement results from the selected configuration mapping table to determine the candidate (cell, beam) pair as the selected candidate; (2) the WTRU selects the highest priority CHO candidate (cell, beam) among the determined candidates; (3) the WTRU activates the antenna panel associated with the selected CHO candidate; (4) the WTRU evaluates the configured execution conditions for the target CHO candidate; and / or (5) if the execution conditions are met, the WTRU performs a conditional CHO to the CHO target cell for the target beam.

[0235] Exemplary embodiments may also include (1) a set of configurations in which BFR / CHO is associated with device mobility and external mobility, (2) a set of BFR / CHO configurations indicated as being associated with QoS requirements of specific applications / services running at the WTRU device, (3) a set of BFR / CHO configurations indicated as being associated with WTRU power consumption requirements, (4) a set of BFR / CHO configurations indicated as being associated with WTRU active subscriptions, (5) only one unified configuration for BFR / CHO provided to the WTRU, (6) BFR and CHO configurations that may indicate priority in candidate situations that may be compared across configurations, and / or (7) a WTRU that may be configured to evaluate both BFR conditions and CHO conditions simultaneously.

[0236] Although features and elements are provided above in specific combinations, it will be understood by those skilled in the art that each feature or element may be used alone or in any combination with other features and elements. The present disclosure may not be limited to the specific embodiments described in this patent application, which are intended to be illustrative of various aspects. Many modifications and variations may be made without departing from the essence and scope of the present invention, as they will be obvious to those skilled in the art. Unless explicitly provided as such, any element, action or description used in the present application specification shall not be understood as being essential or necessary to the present invention. According to the foregoing description, in addition to those listed herein, within the scope of the present disclosure, functionally equivalent methods, devices and products may be obvious to those skilled in the art. Such modifications and variations may be intended to fall within the scope of the appended claims. The present disclosure may be limited only to the terms of the appended claims and the full range of equivalent forms of such entitled claims. It will be understood that the present disclosure is not limited to a specific method or system.

[0237] Although the foregoing embodiments are discussed with respect to specific terminology and structures (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.) for simplicity, the embodiments discussed may not be limited thereto and may be applied to other systems using, for example, other forms of electromagnetic waves or non-electromagnetic waves such as sound waves.

[0238] It will also be understood that the terms used herein are used only for the purpose of describing specific embodiments and are not intended to be limiting. As used herein, the term "video" or the term "imagery" may mean any of a snapshot, a single image, and / or multiple images displayed on a time basis, or any suitable combination thereof. For example, when referred to herein, the term "user equipment" and its abbreviation "UE", the term "remote" and / or the term "head-mounted display" or its abbreviation "HMD" may mean or include (i) a wireless transmission and / or reception unit (WTRU); (ii) any of a plurality of embodiments of the WTRU; (iii) a wireless and / or wired (e.g., tetherable) device configured with (in particular) some or all of the structure and functionality of the WTRU; (iv) a wireless and / or wired device configured with less than all of the structure and functionality of the WTRU; or (v), etc. Figure 1A , Figure 1B , Figure 1C and Figure 1D Details of an example WTRU representing any WTRU described herein are provided herein. As another example, various disclosed embodiments herein above and below may be described as utilizing a head mounted display. One skilled in the art may recognize that devices other than head mounted displays are utilized and some or all of the embodiments of the present disclosure and various disclosed embodiments are modified accordingly without undue experimentation. Examples of such other devices may include drones or other devices configured to stream information to provide an adapted reality experience.

[0239] In addition, the methods provided herein may 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 may include electronic signals (sent via a wired connection or a wireless connection) and computer-readable storage media. Unlike signals, examples of computer-readable storage media may include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as built-in hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with the software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

[0240] Variations of the methods, devices, articles, and systems provided above may be possible without departing from the scope of the present invention. In view of the various embodiments that may be applied, it will be appreciated that the illustrated embodiments are merely examples and should not be considered to limit the scope of the following claims. For example, the embodiments provided herein may include handheld devices that include or are utilized with any suitable voltage source (such as a battery, etc.) that provides any suitable voltage.

[0241] Moreover, in the embodiments provided herein, processing platforms, computing systems, controllers and other devices comprising processors may be indicated. These devices may include at least one central processing unit ("CPU") and memory. According to the practice of those skilled in the art of computer programming, references to symbolic representations of actions and operations or instructions may be performed by various CPUs and memories. Such actions and operations or instructions may be considered to be "executed", "computer executed" or "CPU executed".

[0242] As will be appreciated by one of ordinary skill in the art, the actions and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. The electrical system represents data bits, which may result in the ultimate transformation of electrical signals or the reduction of electrical signals and the retention of data bits at memory locations in the memory system, thereby reconfiguring or otherwise changing the operation of the CPU and performing other processing of signals. The memory locations where data bits are retained may be physical locations having specific electrical, magnetic, optical, or organic properties corresponding to or representing the data bits. The embodiments may not be limited to the above-described platforms or CPUs. Other platforms and CPUs may support the provided methods.

[0243] The data bits may also be maintained on computer-readable media, including magnetic disks, optical disks, and any other volatile (e.g., random access memory ("RAM")) or non-volatile (e.g., read-only memory ("ROM")) mass storage system readable by the CPU. The computer-readable media may include cooperating or interconnected computer-readable media that reside solely on the processing system or distributed across multiple interconnected processing systems that may be local or remote to the processing system. The embodiments may not be limited to the memories described above. Other platforms and memories may support the provided methods.

[0244] In an exemplary embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0245] The above detailed description can list various embodiments of the device and / or process by using block diagrams, flow charts and / or examples. In the case where such block diagrams, flow charts and / or examples include one or more functions and / or operations, it will be understood by those skilled in the art that each function and / or operation within such block diagrams, flow charts or examples can be implemented individually and / or collectively by a wide range of hardware, software, firmware or almost any combination thereof. In exemplary embodiments, several parts of the subject matter described herein can be implemented via application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs) and / or other integrated formats. It will be recognized by those skilled in the art that some aspects of the embodiments disclosed herein can be implemented in whole or in part in an integrated circuit as one or more computer programs running on one or more computers (e.g., one or more programs running on one or more computer systems), one or more programs running on one or more processors (e.g., one or more programs running on one or more microprocessors), firmware, or almost any combination thereof, and according to the present disclosure, designing circuit systems and / or writing codes for software and / or firmware can be fully within the technical scope of those skilled in the art. Those skilled in the art will appreciate that the mechanisms of the subject matter described herein may be distributed as a program product in various forms, and that the illustrative embodiments of the subject matter described herein apply regardless of the specific type of signal-bearing medium used to actually implement the distribution. Examples of signal-bearing media may include, but are not limited to, the following: recordable type media (such as floppy disks, hard drives, CDs, DVDs, digital tapes, computer memory, etc.); and transmission type media (such as digital and / or analog communication media (e.g., fiber optic cables, waveguides, wired communication links, wireless communication links, etc.)).

[0246] Those skilled in the art will recognize that it is common in the art to describe devices and / or processes in the manner set forth herein, and thereafter use engineering practices to integrate such described devices and / or processes into a data processing system. That is, at least a portion of the devices and / or processes described herein can be integrated into a data processing system via a reasonable amount of experimentation. Those skilled in the art will recognize that a typical data processing system generally includes one or more of the following: a system unit housing; a video display device; a memory, such as a volatile memory and a non-volatile memory; a processor, such as a microprocessor and a digital signal processor; a computing entity, such as an operating system, a driver, a graphical user interface, and an application; one or more interactive devices, such as a touch pad or a screen; and / or a control system, including a feedback loop and a control motor (e.g., a feedback for sensing location and / or speed, a control motor for moving and / or adjusting components and / or quantities). A typical data processing system can be implemented using any suitable commercially available components, such as those typically found in data computing / communication and / or network computing / communication systems.

[0247] The subject matter described herein may exemplify different components contained in or connected to different other components. It should be understood that such depicted architectures may be merely examples, and in fact many other architectures that achieve the same function may be realized. In a conceptual sense, any arrangement of components that achieve the same function is effectively "associated" so that the desired function is realized. Therefore, any two components that are combined to achieve a specific functionality herein may be considered to be "associated" with each other so that the desired functionality is realized, regardless of the architecture or intermediate components. Similarly, any two components so associated may also be considered to be "operably connected" or "operably coupled" to each other to achieve the desired function, and any two components that can be so associated may also be considered to be "operably couplable" to each other to achieve the desired function. Specific examples of operable coupling may include, but are not limited to, components that can physically cooperate and / or physically interact and / or components that can wirelessly interact and / or wirelessly interact and / or components that can logically interact and / or components that can logically interact.

[0248] With respect to substantially any plural and / or singular terms used herein, those skilled in the art may translate from the plural to the singular and / or from the singular to the plural as appropriate, as appropriate to the context and / or application. For clarity, various singular / plural arrangements may be explicitly listed herein.

[0249] It will be understood by those skilled in the art that, in general, the terms used herein, especially in the appended claims (e.g., the bodies of the appended claims), are generally intended to be "open" terms (e.g., the term "including" should be interpreted as "including but not limited to", the term "having" should be interpreted as "having at least", the term "comprising" should be interpreted as "including but not limited to", etc.). It will also be understood by those skilled in the art that if a specific number of an introduced claim recitation is intended, such intent may be explicitly stated in the claim, and in the absence of such recitation, such intent is absent. For example, where only one item is intended, the term "single" or similar language may be used. To aid understanding, the following appended claims and / or the description herein may contain the use of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be understood to imply that any particular claim containing such introduced claim recitations is limited to embodiments containing only one such recitation by the indefinite article "a" or "an" to introduce the claim recitation. This is true even when the same claim includes the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "a kind" (e.g., "a" and / or "a kind" should be interpreted as meaning "at least one" or "one or more"). The same applies to the use of definite articles used to introduce claim recitations. In addition, even if a specific number of introduced claim recitations is explicitly recited, one skilled in the art will recognize that such recitation should be interpreted as meaning at least the stated number (e.g., a bare recitation of "two recitations" without other modifiers means at least two recitations or two or more recitations). In addition, in those instances where a convention similar to "at least one of A, B, and C, etc." is used, generally speaking, the meaning of such construction can be that one skilled in the art will understand the convention (e.g., "a system having at least one of A, B, and C" will include, but is not limited to, a system having A alone, B alone, C alone, A and B simultaneously, A and C simultaneously, B and C simultaneously, and / or A, B, and C simultaneously, etc.). In those instances where a convention similar to "at least one of A, B, or C, etc." is used, generally speaking, the meaning of such construction may be that one skilled in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include, but is not limited to, systems having A alone, B alone, C alone, A and B simultaneously, A and C simultaneously, B and C simultaneously, and / or A, B, and C simultaneously, etc.). One skilled in the art may also understand that, in fact, any discrete words and / or phrases presenting two or more alternative terms, whether in the specification, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, any of the terms, or both of the terms.For example, the phrase "A or B" may be understood to include the possibilities of "A" or "B" or "A and B." Additionally, as used herein, the term "any of" followed by a listing of multiple items and / or multiple categories of items may be intended to include "any of," "any combination," "any multiples," and / or "any combination of multiples" of the items and / or categories of items, either alone or in combination with other items and / or other categories of items. Additionally, as used herein, the term "set" may be intended to include any number of items, including zero. Additionally, as used herein, the term "quantity" may be intended to include any quantity, including zero. And, as used herein, the term "plurality" may be intended to be synonymous with "multiple."

[0250] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also described in terms of any individual member or subgroup of members of the Markush group.

[0251] As will be understood by those skilled in the art, for any and all purposes (such as for providing a written description), all ranges disclosed herein may also encompass any and all possible sub-ranges and combinations of their sub-ranges. Any listed range may be easily identified as fully describing and enabling the same range to be divided into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein may be easily divided into a lower third, a middle third, and an upper third, etc. As will be understood by those skilled in the art, all languages ​​such as "up to", "at least", "greater than", "less than", etc. may include the cited numbers and refer to ranges that may subsequently be divided into sub-ranges as described above. Finally, as will be understood by those skilled in the art, ranges may include each individual number. Thus, for example, a group having 1 to 3 units may refer to a group having 1, 2, or 3 units. Similarly, a group having 1 to 5 units may refer to a group having 1, 2, 3, 4, or 5 units, etc.

Claims

1. A wireless transmit / receive unit (WTRU), comprising a transceiver and a processor, wherein the processor is configured to: receiving, via the transceiver, a beam restoring configuration, wherein the beam restoring configuration comprises: an indication of at least one candidate beam; corresponding reference signal information associated with each of the at least one candidate beam; as well as corresponding information associated with each of the at least one candidate beam, wherein the corresponding information includes an indication of at least one coverage area associated with a corresponding candidate beam of the at least one candidate beam; Detecting beam failure conditions; selecting at least one of the at least one candidate beam based at least on the beam failure condition, local sensor data, and a respective coverage area associated with the selected at least one candidate beam; as well as Configuration information associated with the selected at least one candidate beam is transmitted.

2. The WTRU of claim 1 , wherein the processor is further configured to transmit, via the transceiver, an indication that the WTRU is capable of using the local sensor data for beam failure recovery.

3. The WTRU of claim 1 , wherein the beam recovery configuration further comprises a priority associated with each of the at least one candidate beam.

4. According to the WTRU of claim 3, the processor is further configured to select the at least one candidate beam based on the priority associated with each of the at least one candidate beam.

5. According to the WTRU of claim 1, the processor is further configured to select the at least one candidate beam based on the corresponding reference signal information associated with each of the at least one candidate beam.

6. The WTRU of claim 1, wherein the reference signal information comprises at least one of channel state information, reference signal information or random access channel information.

7. The WTRU of claim 1, wherein the information associated with each of the at least one candidate beam comprises at least one of global positioning system information, gyroscope information, accelerometer information, or any combination thereof.

8. The WTRU of claim 1 , wherein the received recovery configuration further comprises: at least one quality criterion associated with each of the at least one candidate beam; as well as A random access channel (RACH) parameter associated with each of the at least one candidate beam.

9. According to the WTRU of claim 8, the processor is further configured to select the at least one candidate beam further based on satisfying at least one corresponding quality criterion, and wherein the configuration information associated with the selected at least one candidate beam is based on the corresponding RACH parameters.

10. A method performed by a wireless transmit / receive unit (WTRU), the method comprising: Receive a beam restoration configuration, wherein the beam restoration configuration comprises: an indication of at least one candidate beam; corresponding reference signal information associated with each of the at least one candidate beam; and corresponding information associated with each of the at least one candidate beam, wherein the corresponding information includes an indication of at least one coverage area associated with a corresponding candidate beam of the at least one candidate beam; Detecting beam failure conditions; selecting at least one of the at least one candidate beam based at least on the beam failure condition, local sensor data, and the corresponding coverage area associated with the selected at least one candidate beam; and Configuration information associated with the selected at least one candidate beam is transmitted.

11. The method of claim 10, further comprising transmitting an indication that the WTRU is capable of using the local sensor data for beam failure recovery.

12. The method of claim 10, wherein the beam recovery configuration further comprises a priority associated with each of the at least one candidate beam.

13. The method of claim 12, further comprising selecting the at least one candidate beam based on the priority associated with each of the at least one candidate beam.

14. The method of claim 10, further comprising selecting the at least one candidate beam based on the corresponding reference signal information associated with each of the at least one candidate beam.

15. The method of claim 10, wherein the reference signal information comprises at least one of channel state information reference signal information or random access channel information.

16. The method of claim 10, wherein the information associated with each of the at least one candidate beam comprises at least one of global positioning system information, gyroscope information, accelerometer information, or any combination thereof.

17. The method of claim 10, wherein the received recovery configuration further comprises: at least one quality criterion associated with each of the at least one candidate beam; as well as A random access channel (RACH) parameter associated with each of the at least one candidate beam.

18. The method of claim 17, further comprising selecting the at least one candidate beam based further on satisfying the corresponding at least one quality criterion, and wherein the configuration information associated with the selected at least one candidate beam is based on the corresponding RACH parameters.

19. At least one computer-readable storage medium having executable instructions stored thereon, which when executed by a processor configure the processor to: Receive a beam restoration configuration, wherein the beam restoration configuration comprises: an indication of at least one candidate beam; corresponding reference signal information associated with each of the at least one candidate beam; as well as corresponding information associated with each of the at least one candidate beam, wherein the corresponding information includes an indication of at least one coverage area associated with a corresponding candidate beam of the at least one candidate beam; Detecting beam failure conditions; selecting at least one of the at least one candidate beam based at least on the beam failure condition, local sensor data, and the respective coverage area associated with the selected at least one candidate beam; as well as Configuration information associated with the selected at least one candidate beam is transmitted.

20. The at least one computer-readable medium of claim 19, wherein: The received beam recovery configuration further includes at least one quality criterion associated with each of the at least one candidate beam; The received beam recovery configuration also includes random access channel (RACH) parameters associated with each of the at least one candidate beam; The selection of the at least one candidate beam is further based on satisfying the corresponding at least one quality criterion; as well as The configuration information associated with the selected at least one candidate beam is based on the corresponding RACH parameters.

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