Joint communication and sensing assisted beam management for nr

Abstract

Methods and apparatuses for receive (Rx) beam selection are described. A wireless transmit / receive unit (WTRU) can be configured to receive, from a base station (BS), configuration information for joint communication and sensing (JCS) reference signals. The configuration information can include resources for reference signal transmissions and resources for measurement reporting. The WTRU can also be configured to receive, from the BS, an indication to activate a subset of the resources for JCS reference signal transmissions. The WTRU can also be configured to transmit a plurality of JCS reference signals using the activated subset of resources for reference signal transmissions. The WTRU can also be configured to measure, via a plurality of Rx beams, backscatter power associated with each of the transmitted plurality of JCS reference signals. The WTRU can also be configured to calculate beam blockage statistics based on the measured backscatter power.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 887,330, filed on August 15, 2019, the contents of which are incorporated herein by reference. Background Art

[0003] Joint Communications and Sensing (JCS) is a technology that enables communications devices with both radio frequency (RF) sensing and radar capabilities. RF sensing and radar capabilities can be built on an enhanced communications framework. Since 5G technologies and systems can operate in upper frequency bands, such as the 28 GHz band, it is possible to converge frequency bands used by different technologies, such as radar and mobile communication systems. Furthermore, there has been significant uptake in consumer devices with radar sensing capabilities in recent years. Given the convergence of frequency bands between radar and mobile communications and the ubiquity of radar-capable consumer devices, technologies that can jointly handle communications and sensing on the same architecture / platform can be more cost-effective and less complex than using two separate platforms. Beam management procedures in systems with high frequency bands can incur significant overhead, which increases with the use of higher frequency bands. Using JCS-enabled devices can help reduce overhead in beam selection procedures due to the ability to detect blockages in receive beams. JCS-enabled devices can take into account estimated blockage statistics, reducing the need for significant overhead in beam selection and beam failure recovery procedures. Therefore, there is a need for methods and apparatus to effectively enable JCS-assisted beam management for New Radio (NR). Summary of the Invention

[0004] Methods and apparatus for receive (Rx) beam selection are described herein. A wireless transmit / receive unit (WTRU) may be configured to receive configuration information for a joint communication and sensing (JCS) reference signal from a base station (BS). The configuration information may include resources for reference signal transmission and resources for measurement reporting. The WTRU may also be configured to receive an indication from the BS to activate a subset of resources for JCS reference signal transmission. The WTRU may also be configured to transmit multiple JCS reference signals using the activated subset of resources for reference signal transmission. The WTRU may also be configured to measure backscatter power associated with each of the multiple JCS reference signals transmitted via multiple Rx beams. The WTRU may also be configured to calculate beam blocking statistics based on the measured backscatter power. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] A more detailed understanding may be obtained from the following description given by way of example with reference to the accompanying drawings in which like reference numerals indicate like elements and in which:

[0006] Figure 1A is a system diagram illustrating an exemplary communication system in which one or more disclosed embodiments may be implemented;

[0007] Figure 1B is a diagram showing that according to one embodiment Figure 1A A system diagram of an exemplary wireless transmit / receive unit (WTRU) for use within a communication system is shown in FIG.

[0008] Figure 1C is a diagram showing that according to one embodiment Figure 1A A system diagram of an exemplary radio access network (RAN) and an exemplary core network (CN) used within a communication system is shown in FIG.

[0009] Figure 1D is a diagram showing that according to one embodiment Figure 1A A system diagram of another exemplary RAN and another exemplary CN used in the communication system shown in FIG.

[0010] Figure 2 is a diagram illustrating an exemplary classification of radar and wireless communication waveforms;

[0011] Figure 3 is a diagram illustrating two exemplary radar architectures;

[0012] Figure 4 is a diagram illustrating an exemplary beam management configuration adaptation based on WTRU beam blocking rate reporting;

[0013] Figure 5 is a diagram illustrating an example of implicit reconfiguration of measurement and reporting periodicity;

[0014] Figure 6 is a diagram illustrating an exemplary WTRU procedure for implicit periodic changes in measurement and reporting configuration;

[0015] Figure 7 is a diagram illustrating an example procedure for coordinated resource configuration switching at a gNB and a WTRU based on implicit signaling;

[0016] Figure 8 is a diagram illustrating an exemplary WTRU procedure for triggered reporting;

[0017] Figure 9 is a diagram illustrating exemplary joint communication and sensing (JCS) measurements resulting in a sensing event;

[0018] Figure 10 is a diagram illustrating an exemplary state flow for a WTRU using a beam blocking event to determine a beam failure; and

[0019] Figure 11 is a diagram illustrating an exemplary procedure for sensing-based beam failure recovery initiation. DETAILED DESCRIPTION

[0020] Figure 1A is a diagram illustrating an exemplary 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 by sharing 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-tailing unique word discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multi-carrier (FBMC), etc.

[0021] like Figure 1A As shown in FIG, a communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112. However, it will be appreciated 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 (STA)) may be configured to transmit 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 smartphone, 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 industrial and / or automated process chain environments), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0022] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a NodeB, an eNodeB (eNB), a Home NodeB, a Home eNodeB, a next generation NodeB such as a gNodeB (gNB), a New Radio (NR) NodeB, 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.

[0023] Base station 114a may be part of the RAN 104, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, one for each sector of the cell. In one 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 transmit and / or receive signals in a desired spatial direction.

[0024] 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).

[0025] 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, and the like. For example, the base station 114a in the RAN 104 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 116. 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 ​​Uplink (UL) Packet Access (HSUPA).

[0026] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may use Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro) to establish the air interface 116.

[0027] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using NR.

[0028] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement both LTE radio access and NR radio access, for example, using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0029] 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 Evolution (GERAN), etc.

[0030] Figure 1A The base station 114b in may be, for example, a wireless router, a Home Node B, a Home eNode B, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business, 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 one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell. Figure 1A As shown, base station 114b may have a direct connection to the Internet 110. Thus, base station 114b may not need to access the Internet 110 via CN 106.

[0031] The RAN 104 may be in communication with the CN 106, 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. 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 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although in Figure 1AAlthough not shown, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize NR radio technology, the CN 106 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0032] The CN 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) from the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0033] 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 WTRU 102c shown in FIG. 1 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.

[0034] Figure 1B is a system diagram illustrating an exemplary 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 supply 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any subcombination of the foregoing elements while still being consistent with an embodiment.

[0035] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and transceiver 120 are depicted as separate components, but it will be appreciated that the processor 118 and transceiver 120 may be integrated together in an electronic package or chip.

[0036] The transmit / receive element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via the air interface 116. For example, in one embodiment, the transmit / receive element 122 can be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 can be an emitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In another embodiment, the transmit / receive element 122 can be configured to transmit and / or receive RF and light signals. It will be appreciated that the transmit / receive element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0037] Although the transmit / receive element 122 Figure 1B Although depicted as a single element in FIG. 1 , 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.

[0038] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0039] 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. Furthermore, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, 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).

[0040] The processor 118 may receive power from the power source 134 and may be configured to distribute power to and / or control power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0041] 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.

[0042] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, Module, FM radio unit, digital music player, media player, video game player module, Internet browser, virtual reality and / or augmented reality (VR / AR) device, activity tracker, etc. Peripheral device 138 may include one or more sensors. The sensor may be one or more of the following: gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor; geolocation sensor, altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biometric sensor, humidity sensor, etc.

[0043] 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 used for UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit that reduces and or substantially eliminates self-interference via hardware (e.g., a choke) or via signal processing performed by a processor (e.g., a separate processor (not shown) or via the processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes used for UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be concurrent and / or simultaneous.

[0044] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 according to one embodiment. As described above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0045] The RAN 104 may include eNode-Bs 160a, 160b, and 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0046] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, etc. Figure 1C As shown, eNode-Bs 160a, 160b, 160c may communicate with each other via an X2 interface.

[0047] exist Figure 1C The CN 106 shown in FIG. 1 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0048] The MME 162 may be connected to each of the eNode-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, and the like. The MME 162 may also 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.

[0049] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNode B handovers, triggering paging when downlink data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0050] 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.

[0051] 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 serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0052] Even though the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative implementations, such terminals may (eg, temporarily or permanently) employ a wired communications interface with a communications network.

[0053] In a representative embodiment, the other network 112 may be a WLAN.

[0054] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access to or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic originating from outside the BSS and destined for a STA may reach through the AP and be delivered to the STA. Traffic originating from a STA destined for a destination outside the BSS may be sent to the AP for delivery to the destination. Traffic between STAs within a BSS may be sent through the AP, for example, where a source STA may send traffic to the AP, and the AP may deliver the traffic to the destination STA. Traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between a source STA and a 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 tunneled DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs (eg, all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0055] When using the 802.11ac infrastructure mode of operation or a similar mode of operation, the AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may be of a fixed width (e.g., a 20 MHz wide bandwidth) or a dynamically set width. The primary channel may be the operating channel of the BSS and may be used by STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. With CSMA / CA, STAs (e.g., each STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected by a particular STA and / or determined to be busy, the particular STA may back off. One STA (e.g., only one station) may transmit in a given BSS at any given time.

[0056] 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.

[0057] Very high throughput (VHT) STAs can support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. 40 MHz and / or 80 MHz channels can be formed by combining contiguous 20 MHz channels. A 160 MHz channel can be formed by combining eight contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels (this may be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, the data can be passed through a segment parser that can split the data into two streams. Each stream can be individually processed with an inverse fast Fourier transform (IFFT) and time domain processing. The streams can be mapped to two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration can be reversed, and the combined data can be sent to the medium access control (MAC).

[0058] 802.11af and 802.11ah support operating modes below 1 GHz. The channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah relative to the channel operating bandwidth and carrier used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter type control / machine type communication (MTC), 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).

[0059] WLAN systems that support multiple channels and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah include a channel that can be designated as a primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by the STA that supports the smallest bandwidth operating mode among all STAs operating in the BSS. In the example of 802.11ah, for a STA that supports (e.g., only) 1 MHz mode (e.g., an MTC-type device), the primary channel may be 1 MHz wide, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, because a STA (that only supports 1 MHz operating mode) is transmitting to the AP, the entire available frequency band may be considered busy even if most of the available frequency band is still idle.

[0060] 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 ranges from 6MHz to 26MHz, depending on the country code.

[0061] Figure 1D1 is a system diagram illustrating the RAN 104 and the CN 106 according to one embodiment. As described above, the RAN 104 may employ NR 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.

[0062] The RAN 104 may include gNBs 180a, 180b, and 180c, though it will be appreciated that the RAN 104 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNBs 180a and 180b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, and 180c. Thus, the gNB 180a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a. In one embodiment, the gNBs 180a, 180b, and 180c may implement carrier aggregation techniques. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In one embodiment, the gNBs 180a, 180b, and 180c may implement coordinated multi-point (CoMP) techniques. For example, the WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0063] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable parameter sets. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of varying or scalable lengths (e.g., containing varying numbers of OFDM symbols and / or varying absolute time lengths).

[0064] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as the eNode-Bs 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 or be connected to the gNBs 180a, 180b, 180c while also communicating or being connected to another RAN, such as the eNode-Bs 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate substantially simultaneously with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c. In a non-standalone configuration, the eNode-Bs 160a, 160b, 160c may serve as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0065] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, interworking between DC, 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 can communicate with each other via the Xn interface.

[0066] exist Figure 1DThe CN 106 shown in FIG1 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0067] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c via the N2 interface in the RAN 104 and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, managing registration areas, terminating non-access stratum (NAS) signaling, mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRUs 102a, 102b, 102c based on the type of services utilized by the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on Ultra Reliable Low Latency (URLLC) access, services relying on enhanced Mobile Broadband (eMBB) access, services for MTC access, etc. The AMFs 182 a and 182 b may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0068] The SMFs 183a and 183b can connect to the AMFs 182a and 182b in the CN 106 via the N11 interface. The SMFs 183a and 183b can also connect to the UPFs 184a and 184b in the CN 106 via the N4 interface. The SMFs 183a and 183b can select and control the UPFs 184a and 184b and configure traffic routing through the UPFs 184a and 184b. The SMFs 183a and 183b can perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing DL data notifications. PDU session types can be IP-based, non-IP-based, Ethernet-based, and so on.

[0069] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N3 interface. This 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 DL packets, providing mobility anchoring, and the like.

[0070] The CN 106 may facilitate communications with other networks. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. Additionally, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may connect to the local DNs 185a, 185b through the UPFs 184a, 184b via the N3 interface to the UPFs 184a, 184b and the N6 interface between the UPFs 184a, 184b and the local DNs 185a, 185b.

[0071] Given that Figures 1A to 1D as well as Figures 1A to 1D As described herein, one or more or all of the functions described herein with respect to one or more of the following may be performed by one or more emulation devices (not shown): the WTRUs 102a-d, base stations 114a-b, eNode-Bs 160a-c, MMEs 162, SGWs 164, PGWs 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other devices described herein. The emulation devices may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation devices may be used to test other devices and / or simulate network and / or WTRU functions.

[0072] The simulation device can be designed to perform one or more tests on other devices in a laboratory environment and / or in a carrier network environment. For example, the one or more simulation devices can perform one or more or all functions when fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. The one or more simulation devices can perform one or more functions or all functions when temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device can be directly coupled to another device for testing and / or use over-the-air wireless communication to perform testing.

[0073] The one or more simulation devices can perform one or more (including all) functions when not 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. The one or more simulation devices can be test equipment. The simulation device can use direct RF coupling and / or wireless communication via RF circuitry (e.g., which can include one or more antennas) to transmit and / or receive data.

[0074] The following terms may be used throughout this document. "Radar" may refer to radio detection and ranging. "JCS" may refer to joint communication and sensing technology or system. "RadCOM" may refer to joint radar and communication technology or system. JCS and RadCOM may be used interchangeably herein. "JCS-RS" may refer to joint communication and sensing reference signal. "TRP" may refer to transmission and reception point. "CSI-RS" may refer to channel state information reference signal. "RNTI" may refer to radio network temporary identity. "C-RNTI" refers to cell RNTI.

[0075] The continued demand for higher user data rates, increased cell capacity, reduced latency, support for the IoT, and other purposes has led to the upcoming 5G wireless technology. In addition to the traditional sub-6 GHz frequency bands that can be used by 4G and previous wireless technologies, 5G wireless systems can use higher frequency bands (e.g., bands above 6 GHz and in the millimeter wave spectrum) where large amounts of spectrum are available.

[0076] Due to the larger available bandwidth in mmWave, these bands can be used to deliver very high data rates (addressing enhanced mobile broadband (eMBB) use cases) and can also be used for enhanced positioning applications. While offering clear advantages in terms of available bandwidth, achievable data rates, and increased accuracy of positioning, waves propagating in higher frequency bands (e.g., mmWave) can suffer from severe attenuation and blocking; to mitigate path loss, highly directional systems (e.g., highly directional beamforming) are desirable. While beamforming is already used in 4G systems, the need for additional transmit (Tx) / receive (Rx) gain to compensate for the high path loss in mmWave may require a more directional system. For example, 3GPP Releases 15 and 16 of the New Radio (NR) specifications may provide support for up to 64 beams in the frequency range up to 52.6 GHz. However, it is expected that for frequencies above 52.6 GHz, the number of beams may increase further, and the corresponding beamwidth may also decrease (e.g., leading to the use of "pencil" beams).

[0077] In order to maintain links for directional systems that support a large number of beams / narrow beams, and to mitigate the impairments unique to mmWave bands (e.g., beam obstruction and / or misalignment), beam management procedures are required. Although Releases 15 and 16 of the 3GPP NR specifications define beam management procedures for bands below 52.6 GHz, there may be large overhead requirements associated with beam management. Overhead may increase as the number of beams increases, and beamwidth decreases at higher frequency bands.

[0078] The availability of large amounts of spectrum (e.g., large channel bandwidths) also enables other applications, such as enhanced positioning, as large channel bandwidths can result in increased resolution in ranging and / or positioning. Furthermore, enhanced positioning information can provide high-resolution detection of objects in the environment, thereby resulting in a clearer physical estimate of the operating environment, also known as radio environment mapping. For wireless networks, this can imply the detection of static and / or moving obstacles and multipath characteristics, which can be crucial for the configuration and optimization of these systems.

[0079] Since ranging (e.g., radar), enhanced positioning, and high data rate communication applications can all benefit from the use of wider channel bandwidths, it may be beneficial to consider technologies that jointly address communication and sensing. Joint Communication and Sensing (JCS) technologies can help reduce complexity and cost by using a common framework to enable seamless and coordinated operation of the communication layer and in-band radar.

[0080] This article describes examples of key performance indicators for radar systems. Two of the most fundamental functions of radar are inherent in the word "radar," which itself is an acronym for the phrase "radio detection and ranging." Furthermore, the ability to determine the azimuth or angular position of a target relative to the transmitter has been derived from the directional transmission of radar signals. Finally, estimating target velocity from the target's Doppler frequency has also become a fundamental function of radar systems.

[0081] As a fundamental function of radar, detection refers to the system's ability to distinguish a target from the background noise and radar clutter of the environment in which the target resides. Key performance indicators of a radar's detection capability may include, but are not limited to, detection range and resolution, or the radar's ability to distinguish between multiple targets at the same location and / or distance from the radar system.

[0082] Detection range can generally be improved by increasing the radar system's transmit power and / or receiver sensitivity, but detection range can also be affected by the radar's operating frequency, which can result in different path losses for the radar signal and different radar cross-sections (RCSs) of detected targets. RCS is a measure of a target's ability to reflect a radar signal in the direction of a radar receiver. RCS can vary with the target's material composition, its position, orientation, and geometry, and the frequency of the radar signal used for detection. Range resolution can also vary with the duration of the radar pulse in non-coherent systems or the bandwidth of the radar pulse in coherent detection.

[0083] A radar's ranging capability refers to the radar system's ability to estimate the distance of a target from the radar receiver. Ranging accuracy can be characterized as ranging resolution, which refers to the margin of uncertainty in the radar system's range estimate and the minimum distance between two targets at which the radar system can detect them. In non-coherent radar detection, the radar system's range resolution decreases linearly with the pulse width of the radar transmission, while for coherent detectors, the range resolution increases linearly with the system bandwidth.

[0084] The azimuth or angular position of a target relative to the radar can be derived from the directional transmission of the radar signal to isolate reflections from limited directions of arrival. In analog beamforming, the limit of angular resolution can be determined by the beamwidth of the radar transmission. Angular resolution can be improved using smart array radar systems, where the limiting factor can be estimation errors from system noise.

[0085] Estimating a target's velocity can be a radar capability achieved by using the Doppler shift of signals reflected off a target when the target is in motion. The shift in frequency of the reflected waveform relative to the transmitted waveform can indicate target mobility, which is proportional to the magnitude of the frequency shift. Estimating target velocity can be challenging due to the presence of multiple targets and / or multipath reflections, which can require complex algorithms to isolate the target source and lead to estimation instability. Furthermore, estimating the velocity of accelerating targets can complicate velocity estimation.

[0086] Figure 2 An exemplary classification of both radar and wireless communication waveforms is depicted. Figure 2 As shown in , radar waveforms can be broadly categorized as either continuous wave radar or pulse-modulated radar. Continuous wave radar may refer to a radar architecture in which radar signals are continuously transmitted and received, while pulse-modulated radar may refer to a system in which transmission and reception are duplexed in time. In communications, radar waveforms can also utilize phase, frequency, and amplitude modulation to aid in target detection. Furthermore, a system using a given architecture (e.g., orthogonal frequency division multiplexing (OFDM)) can be modulated using a variety of different methods (e.g., both or either phase and amplitude modulation in the case of OFDM).

[0087] Pulse radar transmits short pulses and receives echo signals during silent periods. This method is characterized by a very short transmit pulse followed by a very long pause, also known as the receive time. Especially in the presence of multiple targets, pulse radar systems are more naturally capable of estimating target range and bearing, but can suffer from a minimum detection range, which is determined by the time a signal must travel before the radar can transmit a radar pulse and switch to receive mode to detect reflections.

[0088] Continuous wave (CW) radar systems constantly emit electromagnetic radiation. CW radar systems that transmit unmodulated signals may not be able to use the Doppler effect to measure the velocity of a reflecting target. Therefore, in some cases, CW radar systems may not be able to measure range and may be unable to distinguish between two or more targets. In other cases, it is possible to use CW radar systems to measure range by employing frequency modulation, resulting in frequency modulated continuous wave (FMCW) radar. By measuring the frequency of the return signal, the time delay between transmission and reception can be measured, and thus range can be determined.

[0089] An advantage of a CW radar system can be that the energy is not pulsed, which can result in a system that is simpler to manufacture and operate. Such systems may not have a minimum or maximum range, but the transmission power can impose a practical limit on the range. Continuous wave radars can maximize the total power on the target because the transmitter can broadcast continuously. On the other hand, pulsed radar systems can generally provide a greater measurement range with lower power consumption than CW radars (such as FMCW radar systems).

[0090] Continuous waveform radar systems may not have the minimum ranging distance issue and may provide a more natural framework for estimating target velocity, but such systems may perform suboptimally in multi-target scenarios or scenarios involving rich multipath propagation.

[0091] For the purpose of designing radar waveforms that can optimally coexist with modern wireless and mobile communication systems, natural choices for waveforms may include pulse phase waveforms and amplitude modulated waveforms. These types of signals may be most similar to those of wireless communication standards in widespread use around the world.

[0092] Figure 3 Two examples of radar architecture types are shown. Figure 3 As shown in Figure 1, radar architectures can be categorized as either monostatic, where the transmitter and receiver may be co-located, or multistatic, where one or more radios perform transmission and reception is performed by one or more devices at separate locations. Figure 3 As shown in FIG, a monostatic radar system 310 may include a combined transmitter / receiver unit 311. The transmitter / receiver unit may direct a transmission signal toward a target 312 and subsequently receive a reflected signal. As further shown, a multistatic radar system 320 may include a transmitting radio 321 and multiple receivers 322 and 323. Transmitting radio 321 may direct a transmission signal toward a target 324, and receivers 322 and 323 may receive the reflected signals. In embodiments not shown, a multistatic radar system may include multiple transmitters and multiple receivers, multiple transmitting radios with a single receiver, or a single transmitter with a single receiver at a separate location (also referred to as a bistatic radar system). When using more than one transmitter and / or more than one receiver, all or a subset of the transmitters and / or radios may be co-located with other transmitters or receivers of the system.

[0093] A monostatic radar architecture can be simpler, using a single radio to limit time and frequency synchronization challenges, but may suffer from a lack of signal diversity. Monostatic radar architectures can exhibit poor performance in non-line-of-sight (LOS) scenarios or may have suboptimal detection performance for objects with small RCS. Detection performance and range can be increased with a multistatic architecture, at the expense of the implementation complexity required to coordinate transmission and reception between multiple radios.

[0094] It's possible to conceive monostatic, bistatic, and multistatic radar architectures using existing wireless communication hardware, where reflections of the transmitted signal can be observed by either the radio that originally transmitted or a device configured to receive the transmission. However, due to differences in waveform design between radar and communication systems, monostatic architectures can present minimum range issues. If the wireless devices lack full-duplex capabilities, the long transmission period can result in an impractically large minimum range. This limitation can be overcome with multistatic or bistatic architectures, but the network topology will need to implement both point-to-point and point-to-multipoint transmission for optimal design.

[0095] Conventional communication hardware can be valuablely repurposed for wireless sensing. Due to the ubiquity of wireless chipsets for wireless sensing now found in wireless handsets, vehicles, and IoT devices, leveraging these existing chipsets enables new classes of services that can be rapidly deployed and achieve rapid market penetration with minimal infrastructure expenditure. Table 1 shows some of the new applications that have been demonstrated in proof-of-concepts.

[0096]

[0097] Table 1

[0098] This article describes a variety of models / devices / systems for implementing this wireless sensing technology in existing wireless networks. In some examples, a contactless sensor and machine learning hardware platform for health status analysis can be provided. Through such a platform, in addition to tracking human posture and gestures, Wi-Fi signals can also be used to track vital signs (e.g., pulse, breathing rate, etc.). The technology can rely on a proprietary RF transceiver with a customized antenna structure specifically for sensing frequency bands in the range of 5GHz-7GHz. The basic sensing modulation and waveform can be based on FMCW technology, which can be used to separate RF reflections based on the distance of the reflecting object. The micro-Doppler and phase change characteristics of the received signal can be detected by a filtering method based on machine learning, which can then be used to distinguish or detect the characteristics of the object.

[0099] In some examples, modified Wi-Fi network routers can be provided that create sensor networks capable of providing smart car child presence detection, smart home presence monitoring, well-being and sleep monitoring, and indoor tracking and navigation. Software can also be provided that enables the extraction of Wi-Fi-based sensing data from existing Wi-Fi routers and network deployments. Cloud-based applications can be provided that enable enterprise Wi-Fi operators to provide additional tracking and analysis tools for Wi-Fi-based sensing data. Hardware and software modules that utilize UWB (IEEE 802.15.4a) to implement positioning and communication solutions can be provided. In some examples, chips and software development kits (SDKs) can be provided that perform contactless gesture recognition using a proprietary 60 GHz waveform. A customized radar solution specifically for battery-powered end-user devices (such as mobile phones) is one such example. The underlying technology can operate in the 60 GHz ISM band and can be based on FMCW and DSSS modulation classes. The higher frequency bands in which such solutions operate, for example due to spectrum availability and smaller antenna architectures in these bands, can enable higher-resolution applications such as hand / finger gesture recognition.

[0100] This document describes examples of beam management. In NR, beam management can be defined as a set of Layer 1 and / or Layer 2 (L1 / L2) procedures for acquiring and maintaining a set of TRPs and / or WTRU beams that can be used for DL ​​and UL transmission / reception. Beam management can include at least one of several aspects, including beam determination, beam measurement, beam reporting, or beam scanning. Beam determination can involve selecting one or more TRPs or WTRUs from their own Tx / Rx beams. Beam measurement can involve one or more TRPs or WTRUs measuring characteristics of received beamforming signals. Beam reporting can involve a WTRU reporting information about one or more beamforming signals based on beam measurements. Beam scanning can involve the operation of covering a spatial region where beams are transmitted and / or received in a predetermined manner during a certain time interval. Although these procedures may be mentioned in the context of 5G NR, the concepts described herein can be applied to systems implementing other technologies, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless local area networks.

[0101] As part of the initial access procedure, the WTRU and the base station (e.g., gNB) may need to identify a pair of beams (gNB / TRP Tx beam and WTRU Rx beam) for downlink communication. This procedure may be referred to as the "P1" or "beam selection" procedure. For P1, the gNB / TRP may scan the Tx beams to enable the WTRU to perform measurements on different gNB / TRP Tx beams and select the TRP Tx beam and / or WTRU Rx beam.

[0102] Procedure "P2", also referred to as the "Beam Refinement for gNB Tx Beams" procedure, may be used to enable the WTRU to perform measurements on different Tx beams, possibly changing between TRP Tx beams at the same or different TRPs. This procedure may be run on a smaller set of beams and / or beams with smaller beamwidths than procedure P1 (Beam Selection) and may be considered a special case of P1.

[0103] Finally, procedure “P3” may be used to enable the WTRU to perform multiple measurements on the same gNB / TRP Tx beam in order to change the WTRU Rx beam if the WTRU uses beamforming. This procedure may also be referred to as “beam refinement for WTRU Rx beams.”

[0104] Joint communication and sensing may be referred to herein as technology that provides a communication device with RF sensing and radar capabilities. The RF sensing and radar capabilities may be built on an enhanced communication framework (e.g., antennas / processors / memory / systems in infrastructure devices, base stations, UEs, WTRUs, stations, access points, etc.).

[0105] As previously mentioned, 5G technologies and systems may be designed to operate in upper frequency bands, such as the 28 GHz band. This indicates a convergence of frequency bands used by different technologies, such as radar and mobile communication systems. In addition, a significant increase has been seen in consumer devices with radar sensing capabilities. Given the convergence of frequency bands between radar and mobile communications and the ubiquity of consumer devices with radar capabilities, technologies that can jointly handle communication and sensing on the same architecture / platform may be more cost-effective and less complex than two separate platforms.

[0106] Using nodes with combined communication and sensing capabilities enables a wide range of applications. Such applications may include (but are not limited to): indoor sensing, automotive / V2X, industrial IoT applications, and real-time radio environment maps. For indoor sensing, nodes can detect and monitor physical activities, which can be further enhanced with activity classification to classify as human movement, posture, fall detection, vital sign monitoring (e.g., heartbeat), intrusion detection, and others. For automotive / vehicle-to-everything (V2X), nodes perform simultaneous radar and V2X communications and can perform real-time updates to the environment and road maps. For industrial IoT applications, large-scale deployment of nodes can enable indoor positioning in warehouses. Real-time radio environment maps can be constructed using enhanced communication devices.

[0107] Referring again to procedures P1, P2, and P3 described above with respect to initial access, various improvements may be needed to enhance beam management. During the WTRU Rx beam selection procedure (P3), a base station (e.g., gNB) may transmit multiple or repeated CSI-RS using the same spatial domain transmission filter (i.e., the same beam). The number of CSI-RS repetitions may be equal to the number of WTRU receive beams reported for the WTRU's capabilities. However, some of these transmissions may be wasted because the corresponding WTRU Rx beams may be blocked. In addition, the number of blocked repetitions may vary over time due to WTRU mobility. This may result in a waste of network resources, resulting in increased overhead. Therefore, methods and apparatus are desired that can reduce the overhead of CSI-RS transmissions associated with the P3 procedure.

[0108] For Tx beam selection by the base station (e.g., in P1 or P2 procedures), the WTRU may select a beam based on the signal quality of the downlink (DL) transmission. However, this may not take into account the blocking statistics of that beam. The WTRU may receive beams from different TRPs with lower blocking probabilities but similar or worse DL channel qualities. Methods and apparatus that take into account estimated blocking statistics for beam selection are desirable.

[0109] Finally, when the WTRU detects that a beam failure has occurred, the WTRU may trigger beam failure recovery based on DL channel quality measurements. However, this process may have significant overhead and may be slow. Methods and apparatus are desired to accelerate beam failure recovery and reduce the associated signaling overhead.

[0110] Embodiments for beam selection based on obstruction detection are described herein. A WTRU may be configured to transmit a reference signal (RS) at specific times for sensing (e.g., detecting nearby objects). The RS may be used for joint communication and sensing (JCS) or may be dedicated to sensing. The RS configuration may include, but is not limited to, at least one of: periodicity and offset, repetition (the number of symbols or beams over which the RS may be repeatedly transmitted), starting symbol and symbol offset (in the case of non-contiguous symbols being allocated), starting physical resource block (PRB), number of PRBs, PRB offset, RE offset and RE density (number of REs per RB per port), number of ports, power control parameters, and parameters to derive a unique WTRU RS sequence (e.g., sequence ID, cyclic prefix, etc.).

[0111] The RS configuration may be conveyed to the WTRU in RRC signaling (e.g., in an RRC configuration message) and may be activated as soon as the WTRU enters the RRC connected state. Alternatively or in addition, the RS configuration may be received in the RRC configuration and a separate activation or deactivation message may be received over a downlink control channel in a downlink Medium Access Control-Control Element (MAC-CE) or in Downlink Control Information (DCI). The downlink control channel may be masked or scrambled (e.g., using a cyclic redundancy check (CRC)) using the WTRU's RNTI (e.g., C-RNTI). Alternatively or in addition, the RS configuration and activation may be received simultaneously in the DCI over a downlink control channel scrambled using the WTRU's RNTI (e.g., C-RNTI). The network (e.g., gNB, eNB, or base station (BS)) may allocate a new identity (e.g., JCS-RS-RNTI) for this purpose, which the WTRU may use to descramble the DCI containing the RS configuration. Alternatively or additionally, the RS configuration may be received in signaling on a downlink shared channel, where the resources for the shared channel may be indicated in a DCI scrambled with the WTRU's RNTI (e.g., C-RNTI, JCS-RS-RNTI).

[0112] Alternatively or additionally, other uplink RSs configured for the WTRU (eg, sounding reference signal (SRS) and / or demodulation reference signal (DMRS)) may be used for sensing purposes.

[0113] To perform sensing, the WTRU may transmit a RS on the configured resources. After transmitting the RS, the WTRU may monitor the backscatter and perform measurements on the backscatter. To perform backscatter measurements, the WTRU may perform at least one of several procedures. For example, the WTRU may measure the received power of the backscatter; measure the phase of the backscatter; estimate the channel impulse response of the backscatter and / or related parameters of the channel impulse response (e.g., round-trip time, delay spread, path loss, etc.); and / or perform a cross-correlation between the received backscatter and the sequence used to transmit the RS.

[0114] The WTRU may be configured to perform measurements at different frequency domain granularities, for example, on a wideband or / and sub-band basis. For sub-band based measurements, the sub-band configuration (i.e., number of sub-bands, number of physical resource blocks (PRBs) per sub-band, starting PRB for each sub-band, etc.) may be given to the WTRU. In some embodiments, for example, in the case of a beam-based system, the WTRU may monitor and measure backscatter on the receive beam corresponding to the transmit beam used to transmit the RS.

[0115] Embodiments for determining beam blockage ratio are described herein. Based on backscatter measurements, the WTRU may be configured to report at least one of the following: the number of blocked beams, the beam blockage ratio, the Rx signal strength on the backscatter signal for each beam, or a wideband or sub-band based measurement.

[0116] In some embodiments, the report (i.e., beam blocking report) can be configured as periodic, semi-persistent, or aperiodic reporting. The time-frequency resources of the report (e.g., periodicity and offset, symbol index or starting symbol and number of contiguous symbols, PRB index or starting PRB and number of contiguous physical resource blocks) can be configured on an uplink control channel (e.g., physical uplink control channel (PUCCH)) or an uplink shared channel (e.g., physical uplink shared channel (PUSCH)).

[0117] The parameters of the beam blocking report configuration may include (but are not limited to) at least one of the following: time-frequency resources (e.g., using PUCCH or PUSCH); number of reports (e.g., the number of blocked beams, and / or beam blocking rate, etc.); one or more parameters associated with blocking detection (e.g., detection threshold, etc.); or the number N of measurement cycles to obtain average statistics.

[0118] The reporting configuration may be communicated to the WTRU (e.g., in an RRC configuration or system information). Alternatively or additionally, a given reporting configuration may be later activated or deactivated by sending an activation or deactivation command using a downlink control channel (e.g., communicated in an RRC configuration). The command may be signaled on a downlink channel using downlink control information (DCI) scrambled or masked with an identifier such as the WTRU's RNTI.

[0119] By monitoring and measuring the backscatter of the transmitted RS on a receive beam, the WTRU may determine blockage in the direction of that beam. The WTRU may use a detection threshold to detect the blockage. For example, if the received backscatter power on a receive beam is greater than the detection threshold, the WTRU may declare the receive beam to be a blocked receive beam. In some embodiments, the WTRU may declare the receive beam to be an unblocked receive beam. The detection threshold may be communicated to the WTRU, for example, as part of a beam blockage reporting configuration.

[0120] The WTRU may perform a blockage detection for each of the beams on which the RS is transmitted for sensing purposes. Based on the blockage detection, the WTRU may calculate the number of blocked beams out of the total number of beams for which measurements were performed. If the WTRU is configured to report a beam blockage ratio, the WTRU may determine the measurement of the number of blocked beams over a number of periods (e.g., N configured for the WTRU as part of the beam blockage reporting configuration) that the WTRU uses. For example, the WTRU may calculate the beam blockage ratio by taking the average or median of the number of blocked beams over N measurement periods. The WTRU may calculate the beam blockage ratio by taking a simple average over N measurement periods (e.g., the sum of the blocked beams over the first N measurement periods divided by N). Alternatively or in addition, the WTRU may calculate the beam blockage ratio by taking an exponential moving average. For example, the exponential moving average at the Kth reporting instance (i.e., Average(K)) that may be calculated using Equation 1 is shown below:

[0121] Average(K)=W*Average(K-1)+(1-W)*Measurement(K) Equation 1

[0122] As expressed in Equation 1, measurement (K) can be the number of blocked beams observed by the WTRU in the most recent measurement period (e.g., the Kth period), and W can be a weighting factor that can be transmitted to the WTRU, for example, as part of the beam blocking report configuration.

[0123] Alternatively or in addition, the WTRU may be configured to report beam blockage statistics for one or more specific beams. Beam indications may be defined with respect to the serving beam. For example, the WTRU may be configured to report beam blockage rates for a set of beams covering a first angle 'θ' from the right ('clockwise') of the serving Rx beam. The WTRU may be configured to report one or more beam blockage reports along with one or more beam indications / identifications (e.g., number of beams, direction, θ, associated (e.g., co-located) synchronization signal block (SSB) ID or SRS ID or CSI-RS ID, etc.).

[0124] In some embodiments, for each of the reporting instances / resources, the WTRU may prepare a report containing the required beam blocking statistics (e.g., the number of blocked beams, and / or the beam blocking rate, and / or the Rx signal strength on the backscattered signal for each beam) for each configured wideband or sub-band and may send the report to the network (e.g., gNB / eNB / BS) on the configured resources.

[0125] In some embodiments, the network (e.g., gNB / eNB / BS) may use beam blocking statistics received in one or more beam blocking reports from the WTRU to determine one or more parameters of the WTRU. For example, the network may determine the number of CSI-RS resources that need to be configured for receive beam scanning of the WTRU. This may be the number of CSI-RS resources that need to be configured in one or more CSI-RS resource groups with "repeat=on" configured for the WTRU. In some examples, the network (e.g., gNB / eNB / BS) may use beam blocking statistics received in one or more beam blocking reports from the WTRU to determine the number of SRS resources that need to be configured for the WTRU. Alternatively or in addition, the beam blocking statistics and one or more beam indications from the WTRU may be used to derive obstacles or the mobility pattern of the WTRU.

[0126] Figure 4 An exemplary beam management configuration adaptation based on WTRU beam blocking rate reporting is illustrated. As shown at 401 in this example, WTRU 400b may provide parameters indicating the WTRU's capabilities, such as the maximum number of Rx beams supported by the WTRU, to gNB 400a. At 402, WTRU 400b may be configured by gNB 400a with the number of CSI-RS transmission repetitions for WTRU Rx beam selection. In some embodiments, the number of CSI-RS repetitions, N, may be less than or equal to the maximum number of Rx beams supported by the WTRU. In some embodiments, the gNB may use the same Tx antenna configuration for all repetitions, and the WTRU may switch the Rx antenna configuration for each repetition.

[0127] Furthermore, to enable the WTRU 400b to determine obstacles in different directions, it may be configured with P resources for JCS-RS transmission and measurement, as shown at 403. In the embodiment shown, P may be less than or equal to the maximum number of Rx beams that the WTRU can support. The WTRU may be configured with resources set up for reporting JCS measurements. The resources for JCS-RS transmission and measurement and the resources for measurement reporting may be designated in the same configuration or separately, as shown at 403 and 404.

[0128] As shown at 405, the WTRU may transmit a JCS-RS in the configured resources and measure the backscatter power using the corresponding Rx beam. The WTRU may repeat the transmission using different beams if multiple resources are configured in the resource set and use the corresponding Rx beams. At 406, the WTRU may calculate the beam blocking ratio based on the measured backscatter power, for example according to the embodiments described herein. Using the resources configured for JCS measurement reporting, the WTRU may transmit a report containing the beam blocking ratio, which may be expressed as K in this example. The WTRU may then receive a new Rx beam selection configuration containing a different number of resources (less than or equal to MK in this example), which is shown at 407.

[0129] Embodiments for reconfiguring backscatter measurement and obstruction reporting are described herein. In some embodiments, periodic changes may be implicitly signaled. Different rates for backscatter measurement and obstruction reporting may be required based on one or more factors. Such factors may include, for example, WTRU mobility or specific deployment scenarios (e.g., busy roads, mountainous areas, residential areas, etc.). For example, for a static WTRU (or a WTRU with minimal mobility), a slower rate of backscatter measurement and obstruction reporting may be appropriate, while for a WTRU with high mobility, a faster rate of backscatter measurement and obstruction reporting may be appropriate. Alternatively or in addition, the rate of change of the channel characteristics between the transmitter and the receiver may determine the reporting periodicity requirement. To enable the WTRU to operate in accordance with such measurement and reporting requirements, in some embodiments, the WTRU may be configured with multiple groups of resources for RS transmission for backscatter measurements. Each group may differ in at least one of several parameters. Such parameters may include periodicity; repetition; starting symbol and symbol offset (in case non-contiguous symbols are allocated); starting PRB, number of PRBs and PRB offset; RE offset and RE density (number of REs per RB per port); and / or number of ports.

[0130] In some embodiments, the WTRU may be configured with multiple sets of resources for reporting blocking statistics. Each set may differ in at least one of the reported parameters, such as the periodicity in the case of periodic reporting. The multiple configured sets of resources for RS transmission and reporting may be communicated to the WTRU, for example, via RRC configuration.

[0131] The initial or default selection of a set of resources for RS transmission and a set of resources for barring reporting may be communicated to the WTRU in an RRC configuration, for example, via a downlink MAC-CE message or via downlink control information (DCI) transmitted on a downlink control channel.

[0132] One or more parameters may be configured for the WTRU to implicitly activate or deactivate resource groups for RS transmission and / or barring reporting. Examples of parameters for implicitly activating or deactivating resource groups for RS transmission and / or barring reporting may include, but are not limited to, a periodicity threshold 1 (e.g., T1) and calculation method, and a periodicity threshold 2 (e.g., T2). The calculation method may use, for example, an "always one-step" method or a "functional" method (with other parameters, such as a step threshold), etc.

[0133] In some embodiments, the WTRU may use a periodicity threshold 1 (T1) to determine the periodicity of resources used for RS transmission and blocking reporting. The periodicity threshold 1 (T1) may refer to a measurement change that, when exceeded, triggers an increase in the rate of RS transmission and blocking reporting (or a decrease in the rate of RS transmission and blocking reporting when the measurement change does not reach the threshold). The measurement change may refer to the absolute difference between the current measurement value (e.g., the blocking rate or number of blockings measured based on the current measurement period) and the previously reported measurement value (e.g., the blocking rate or number of blocked beams in the previous measurement period).

[0134] In some embodiments, the calculation method of the new rate or periodicity value may be configured for the WTRU. For example, in the "always one step" method, when the measurement value change is found to be greater than the T1 threshold, then the next lower periodicity value may be selected for both cases (i.e., for RS transmission and blocking reporting). Alternatively or in addition, in the "functional" method, the new periodicity value may be configured based on the measurement value change. For example, the new periodicity may be defined as shown in Equation 2 below:

[0135]

[0136] In the event that there is no periodicity value configured for any resource group that is equal to the resulting new periodicity, the WTRU may select the closest value among the different configured values.

[0137] In some embodiments, the WTRU may also use a periodicity threshold 2 (T2) to determine the periodicity of resources used for RS transmission and blocking reporting. The periodicity threshold 2 (T2) may refer to the number of measurement periods after activation of the current set of resources used for RS transmission and blocking reporting, during which a decrease in the rate of RS transmission and blocking reporting (or an increase in the periodicity of RS transmission and blocking reporting) is triggered if the measurement value (e.g., blocking rate or number of blocked beams) does not change significantly (e.g., the average measurement value change over the last T2 periods is less than or equal to T1). If the measurement value has not changed significantly over the last T2 periods, the next higher periodicity value may be selected for both cases (i.e., for RS transmission and blocking reporting). Alternatively or in addition, the new periodicity value may be configured based on the number of measurement periods during which the measurement value has not changed significantly.

[0138] In some embodiments, based on configured thresholds and calculation methods, when the WTRU determines to decrease or increase the current periodicity, the WTRU may be configured to switch to a new set of resources for RS transmission and blockage reporting after transmitting the current / latest measurement value. In some cases, the WTRU may perform the switch to the new set of resources after being configured with the new periodicity value. For example, if the current or latest blockage report is configured to be sent using the uplink control channel or UCI in time slot 'n', the WTRU may assume that the new set of resources (i.e., for RS transmission and blockage reporting) should be used starting after a time offset. In one example, in time slot 'n+K1', where K1 may be a time offset communicated to the WTRU as part of the beam blockage report configuration or RS configuration, for example. Different offsets may be configured for RS configuration and blockage reporting. For example, a time offset K1 may be applied for RS configuration and a time offset K2 may be applied for blockage reporting. After transmitting the blockage report in time slot 'n', the WTRU may deactivate the current RS transmission and backscatter measurement and / or reporting.

[0139] Alternatively or additionally, if the blocking report is configured to be sent using an uplink shared channel (e.g., PUSCH), the WTRU may assume that a new set of resources (i.e., for RS transmission and blocking report) should be used starting from time slot 'n1+K3', where 'n1' is the time slot in which the WTRU receives a downlink acknowledgment of the current / latest blocking report on PUSCH, and K3 may be transmitted to the WTRU, for example, as part of the beam blocking report configuration or RS configuration. This downlink acknowledgment may be, for example, a hybrid automatic repeat request acknowledgement (HARQ-ACK) or a DCI having the format DCI0_0 or DCI0_1, where the new data indicator (NDI) = '1' for the HARQ process used for the report transmission. In some embodiments, the WTRU may assume that the start of the new set of resources (i.e., for RS transmission and blocking report) may be applied starting from time slot 'n+drx-RetransmissionTimerUL', where the latest blocking report is sent using PUSCH in time slot 'n'.

[0140] Figure 5 is an example of an implicit reconfiguration of measurement and reporting periodicity. Figure 5 As shown at 501 in FIG. 5 , WTRU 500b may receive a measurement and reporting resource configuration from gNB 500a. As shown, the measurement and reporting configuration may include multiple groups of RS configurations for backscatter measurements and multiple groups of reporting configurations (groups with different periodicities P-2, P, P+2), thresholds T1 and T2, and offsets O1, O2, and O3. Figure 5 In the case of , the periodicity value may be explicitly configured for a "one-step only" system. The WTRU 500b may receive the measurement and reporting configuration in RRC signaling. In the embodiment shown at 502, the gNB 500a may transmit to the WTRU 500b an indication to activate measurement and reporting using a subset of previously configured resources and parameters (e.g., a set of RS configurations with periodicity = P and a set of reporting configurations). Figure 5 As shown in , this indication may be provided via MAC-CE. At 503, the WTRU 500b may repeatedly perform backscatter measurements for each RS using different beam directions and calculate or update a first beam blocking ratio which may be expressed as R1. Figure 5 In the embodiment shown in FIG, WTRU 500b may begin backscatter measurements and blockage reporting after a time offset (e.g., O2) from receiving indication 502. The specific offset to be used may be indicated in the MAC-CE for activation at 502. After calculating or updating the beam blockage rate, WTRU 500b may transmit a report containing beam blockage statistics, for example, on the PUSCH. At 504, gNB 500b may transmit an acknowledgment to WTRU 500a after receiving the report.

[0141] At 505 and 507, the WTRU 500b may again perform backscatter measurements and blockage reporting based on the periodicity P indicated in the MAC-CE message at 502. In each case, the WTRU 500b may evaluate the current beam blockage ratio (e.g., R2 and R3) relative to the previously determined beam blockage ratio (e.g., R1 and R2 for steps 505 and 507, respectively) and determine whether to adjust the measurement and reporting periodicity by comparing the change in beam blockage ratio to a threshold value T1. The WTRU 500b may transmit a report including the determined statistics, and upon receiving the report, the gNB 500a may again transmit an acknowledgment, as shown at 506 and 508.

[0142] If the WTRU 500b determines that the change in beam blockage ratio exceeds a configured threshold, the WTRU 500b may determine to increase the measurement and blockage reporting rate (i.e., decrease the periodicity). For example, as shown at 509, the WTRU 500b may activate a set of configured measurement and reporting resources and determine to use a periodicity value and offset value O1 for the P-2 time slot. The WTRU 500b may begin backscatter measurements and blockage reporting in the configured resources at 5010 after the time offset O1, and again at 512 and 514 according to the configured periodicity for the P-2 time slot. In the embodiment shown at 511, 513, and 515, the WTRU may receive an acknowledgment of the report from the gNB 500a. The WTRU 500b may monitor the change in beam blockage ratio for a number of consecutive measurement periods equal to the periodicity threshold T2. If the average change in beam blockage rate over consecutive measurement periods is sufficiently low (e.g., does not exceed a threshold value T1), the WTRU 500b may determine to reduce the frequency of performing backscatter measurements and blockage reporting. Accordingly, the WTRU 500b may again adjust the measurement and reporting frequency by activating / deactivating one or more sets of measurement and reporting resources and parameters, as shown at 516.

[0143] Figure 6 is an example procedure performed by a WTRU for adjusting measurement and reporting periodicity. As shown at 601, the WTRU may receive an RRC configuration message with multiple sets of RS configurations for backscatter measurements and multiple sets of reporting configurations (with different periodicities). The RRC configuration message may include one or more periodicity thresholds (e.g., Figure 6) in the context of , and an indication to adjust the measurement and reporting using an 'always one-step' calculation method. At 602, the WTRU may receive a selection or activation of one of a plurality of groups of RSs and one of a plurality of groups of reporting configurations. The selection or activation may be signaled to the WTRU, for example, in a MAC-CE message. Based on the initial selection or activation, the WTRU may further set a parameter of the previous beam blocking ratio to be equal to 'null'. At 603, the WTRU may perform an RS transmission on the next configured resource, perform backscatter measurements, and calculate or update the current beam blocking ratio. At 604, the WTRU may send a report including the beam blocking ratio on the next configured uplink resource. The transmission on the next uplink resource may be performed, for example, on a PUSCH.

[0144] At 605, the WTRU may evaluate whether the previous beam blocking ratio is or is not 'null'. If it is 'null', the WTRU may set the previous beam blocking ratio equal to the current beam blocking ratio (shown at 608) and may determine that no change is needed to the current configuration of RS transmission and reporting (shown at 609). If the previous beam blocking ratio is not 'null', the WTRU may then proceed to determine at 606 whether the change in beam blocking ratio (e.g., the difference between the current beam blocking ratio and the previous beam blocking ratio) exceeds a threshold T1. If not, the WTRU may again determine (e.g., at 609) not to perform a change in the configuration of RS transmission and reporting. If the change in beam blocking rate exceeds the threshold T1, the WTRU may proceed to determine whether an acknowledgment of the measurement report (e.g., HARQ-ACK, DCI format 0_0 or DCI 0_1 with NDI=1) has been received at 607, or alternatively, whether a timer for requesting retransmission (e.g., drx-RetransmissionTimerUL corresponding to the HARQ process used for the report transmission) has expired. If an acknowledgment has been received, or if the timer for requesting retransmission has expired, then at 610, the WTRU may adjust the RS and reporting configuration using the next lower configured periodicity relative to the current periodicity.

[0145] Figure 7 is an example of a procedure for enabling resource configuration adjustments without explicit signaling in the context of Joint Communications and Sensing (JCS). Figure 7, as depicted at 701, WTRU 700b may receive a JCS-RS configuration from gNB 700a. The JCS-RS configuration may specify one or more resource groups, each resource group having N resources. At 702, WTRU 700b may also receive a JCS measurement report configuration, which may include one or more resource groups for transmitting measurement reports and / or one or more thresholds for adjusting measurement and reporting configurations. At 703, WTRU 700b may determine a default resource group for JCS measurements and a default resource group for reporting. At 704, WTRU 700b may transmit JCS-RS using a number of beams (i.e., for example, equal to the number of resources specified in the JCS-RS configuration at 701). WTRU 700b may measure the backscatter power on the corresponding Rx beam at a given periodicity. The periodicity may depend on the JCS measurement resource group determined at 704. Based on the measured backscatter power, WTRU 700b may calculate the beam blocking rate (shown at 705) and transmit a JCS measurement report at 706 that may include the beam blocking rate. Similar to the measurement periodicity, the reporting periodicity may depend on the selected JCS reporting resource group. In this example, based on the WTRU JCS measurement reports, gNB 700a and WTRU 700b may determine a configuration change, adjustment, or switch as shown at 707a and 707b. In some embodiments, WTRU 700b or gNB 700a may independently determine the change. For example, if the gNB makes this determination (e.g., based on the received measurement report), the gNB may indicate the change to the WTRU. If the WTRU makes this determination independently or implicitly, the WTRU may initiate a resource change without input from the gNB. If the current measurement differs by a significant amount from the past L (>= 1) values, an adjustment to the configuration may be prompted. The WTRU may be configured using a threshold to determine when a configuration change is required. It should be noted that the threshold and the number of times (L) that the threshold needs to be exceeded before triggering a configuration switch may be different in the two cases when the current measurement is more or less than the previous measurement. The parameter L may be configured at the WTRU by the gNB at 701 via, for example, JCS-RS configuration, via another signal received from the gNB during resource configuration adjustment, or separately via, for example, RRC or other control signaling.

[0146] Embodiments of explicit signaling for reconfiguring backscatter measurements and blockage reporting are described herein. In some embodiments, the WTRU may determine to reconfigure one or more parameters for RS resources and / or blockage reporting based on one or more factors. For example, the WTRU may determine that a higher or lower rate (e.g., compared to the rate for valid resources) of measurement and reporting is needed based on the WTRU's mobility or changes in measurement values ​​(e.g., similar to the mechanisms described above). In some embodiments, the WTRU may determine that a higher or lower value needs to be repeated (i.e., a higher or lower number of symbols or beams should be allocated for RS transmission in a period), or that a change in the frequency granularity of the measurement is needed based on the resolution of the measurement value (e.g., received power of backscatter).

[0147] In some embodiments, the WTRU may be configured to send a request to the network (e.g., gNB / eNB / BS) to indicate that reconfiguration of RS resources for backscatter measurements or / and resources for reporting is required. The WTRU may use a multi-bit field to indicate the request, where multiple bits (e.g., two bits) may be dedicated to each parameter that may be reconfigured. For example, two bits corresponding to a parameter, i.e., '00', '01', '10', may indicate that the current value of that parameter does not need to be changed or is to be decremented or incremented, respectively. Reporting resources may be used to allocate uplink resources for sending indications to the network. For example, based on determining that one or more parameters are to be modified, the WTRU may append a multi-bit value to the current report (i.e., set the value as requested).

[0148] After sending an indication or request for reconfiguration to the network, the WTRU may monitor for reconfiguration messages from the network (e.g., reconfiguration of current resources for measurement and / or reporting). For example, the WTRU may receive the reconfiguration in an RRC reconfiguration message. Alternatively or in addition, the WTRU may receive a MAC-CE message or DCI containing an indication to activate a new set of resources (e.g., among the multiple sets of resources configured in the RRC configuration). In some embodiments, the MAC-CE message or DCI may also contain an indication to deactivate previously active resources (e.g., implicitly or explicitly).

[0149] Embodiments for triggered reporting are described herein. In order to perform blockage reporting based on backscatter measurements, a WTRU may be configured using event-based triggering. For example, for blockage reporting, an event may be configured, and when this event occurs or is triggered, the WTRU may send the measured value to the network. For example, the event may be configured such that if a backscatter measurement (e.g., beam blockage rate) changes or exceeds a trigger threshold, then the event trigger condition is satisfied, and therefore a measurement report containing the current measured value may be reported to the network (e.g., gNB / eNB / BS). The change in the measurement value may refer to the absolute difference between the current measurement value (e.g., the blockage rate or number of blockages measured based on the current measurement period) and the previously reported measurement value (e.g., the blockage rate or the number of blocked beams). In another example, the WTRU may be configured to monitor multiple measurements, and the event trigger condition may be deemed satisfied if all of the multiple measurements, or the value obtained using all of the multiple measurements, differ from the previously reported measurement by a trigger threshold. In some embodiments, the plurality of measurements to be monitored may cover the number of measurements within a configured period (ie, the "trigger time"), and the resulting value may be an average of the measurements.

[0150] In some embodiments, RS transmission for measurement may also be triggered based on an event. For example, the WTRU may transmit a JCS-RS on configured resources when it senses movement / rotation of the WTRU, which may be possible using, for example, a gyroscope, accelerometer, etc. within the device. In some embodiments, the configuration of the triggered report using event definitions and other parameters (e.g., trigger threshold, trigger time) may be conveyed to the WTRU, for example, in RRC signaling (e.g., RRC configuration).

[0151] After the event triggering condition is met, the WTRU may transmit a report containing the latest measured values ​​to the network. The WTRU may send the report using an uplink channel (e.g., PUSCH). If the WTRU does not have any uplink resources available, the WTRU may send a scheduling request to receive a grant of resources. Alternatively or in addition, the blocking report based on backscatter measurements may be configured as a triggered report based on a Layer 3 (L3) event. The WTRU may send the measurement report using an uplink L3 message, which may be, for example, an RRC message.

[0152] Figure 8An example of a WTRU procedure for triggered reporting is illustrated. At 801, a WTRU configured to perform this procedure may receive a configuration for backscatter measurements of an RS. The configuration may also include a triggered reporting configuration that may provide, for example, event definitions, trigger thresholds, and the number of measurement periods N that may be used to trigger reporting. Upon receiving this configuration, the WTRU may set a parameter k equal to the number of measurements already performed. If no measurements have been performed, the WTRU may set k equal to 0 and another parameter, 'Previously Reported Measurements', equal to 'NULL' to indicate that no measurements have been reported. At 802, the WTRU may wait for the next configured measurement, perform an RS transmission on the configured resources, perform backscatter measurements, and / or store the resulting values. The WTRU may increment the parameter k by one to indicate that a measurement has been performed. At 803, the WTRU may evaluate whether the number of measurements k performed is equal to or greater than the number of measurements or periods N used to trigger reporting. If not, the WTRU may again perform the procedure described at 802 and perform, record, and store measurements for the next RS transmission. If k meets or exceeds N, then at 804, the WTRU may calculate the average of the measurements over the N periods in which the measurements were performed. At 805, the WTRU may evaluate whether the 'Previously Reported Measurement' field is 'NULL'. If so, then at 807, the WTRU may set the previously reported measurement field equal to the average measurement calculated at 804. If not, then at 806, the WTRU may evaluate whether the difference between the average measurement calculated at 804 and the value of the parameter 'Previously Reported Measurement' exceeds a configured trigger threshold. Finally, as shown at 807, the WTRU may be configured to average the measurements over the N periods, and if the average differs from the previously reported measurement by more than the 'Trigger Threshold', the WTRU may send a report to the network, which is shown at 808. The WTRU may also set the parameter 'Previously Reported Measurement' equal to the average measurement calculated at 804.

[0153] Embodiments for implicitly reconfiguring CSI-RS / SRS resources are described herein. In some embodiments, the network may use blocking reports based on backscatter measurements from the WTRU (e.g., a measurement of the beam blocking ratio or the number of blocked beams) to enable efficient resource management. For example, the number of CSI-RS configured within a CSI-RS group may be updated based on the beam blocking ratio (e.g., the number of CSI-RS configured using the parameter "repeat=on"). In another example, the number of SRS (i.e., the number of beams used for SRS) may be updated based on the beam blocking ratio from the WTRU.

[0154] In some embodiments, after a blocking report, the WTRU may be configured to update a downlink and / or uplink reference signal (e.g., downlink CSI-RS or uplink SRS) configuration that may be different from the active reference signal configuration. The WTRU may be configured with multiple sets of reference signals, for example, multiple CSI-RS resource groups with different numbers of CSI-RS resources (where "repeat=on"), or / and multiple SRS resource groups with different numbers of SRS resources. If the WTRU determines that the currently reported value (e.g., beam blocking report) is different from the previously reported value, the WTRU may select a new CSI-RS resource group and / or SRS resource group from the multiple configured resource groups. For example, the WTRU may calculate the number of required CSI-RS resources as the difference between the WTRU's maximum Rx beam capability and the reported value of the beam blocking ratio. Based on the calculated number of required CSI-RS resources, the WTRU may select a resource group with the same or closest number of CSI-RS resources as the calculated number of required CSI-RS resources.

[0155] If a beam blocking report is configured to be sent using the uplink control channel or UCI in a given time slot 'n', the WTRU may assume that a new set of resources (i.e., a CSI-RS resource group or / and SRS resource group with 'repeat=on') may be used starting in time slot 'n+L1', where L1 is an offset that may be communicated to the WTRU, for example, as part of the beam blocking report configuration or CSI-RS / SRS configuration. Different offsets may be configured for different RSs (e.g., one of the CSI-RS and the other of the SRS).

[0156] Alternatively or in addition, if the blocking report is configured to be sent using an uplink shared channel (e.g., PUSCH), the WTRU may assume that a new set of resources (i.e., a CSI-RS resource group and / or SRS resource group with 'repeat=on') may be used starting in slot 'n1+L2', where 'n1' is the slot in which the WTRU received a downlink acknowledgment of the most recent blocking report on PUSCH. This downlink acknowledgment may be a HARQ-ACK or a DCI with format DCI 00 or DCI 01, where NDI='1' for the HARQ process used for the report transmission. L2 may be transmitted to the WTRU, for example, as part of the beam blocking report configuration or CSI-RS / SRS configuration. In another embodiment, the WTRU may assume that a new set of resources may be used starting in the next slot after the maximum duration until a grant for an UL retransmission may be received. This may be, for example, when a timer (eg, drx-RetransmissionTimerUL) for the HARQ process of the PUSCH on which the latest blocking report was transmitted has expired.

[0157] In some embodiments, for example when the WTRU receives an explicit command from the network (e.g., in RRC signaling, in downlink MAC-CE, or in DCI) containing the selection or activation of a CSI-RS resource group and / or SRS resource group, the WTRU may deactivate the currently active configuration and may activate the new configuration explicitly received from the network.

[0158] Embodiments for sensing-assisted beam selection are described herein. Additionally, embodiments for blocking rate-based beam selection for sensing-assisted beam selection are described herein.

[0159] A WTRU may be configured to calculate and report blocking statistics for one or more Tx beams of a gNB (e.g., a serving gNB / TRP). For example, a WTRU may be configured to calculate and report beam blocking rates for one or more Tx beams of its serving gNB. A Tx beam may be identified based on a synchronization signal block (SSB) transmitted on that beam, where each SSB is assigned an index. In order to calculate blocking statistics for one or more Tx beams of a gNB, the WTRU may be configured with an uplink RS configuration for backscatter measurements (or SSB identifier or index) corresponding to each of the Tx beams for which blocking statistics need to be calculated (e.g., for sensing purposes only, or for joint communication and sensing purposes). In addition to the parameters mentioned for the uplink RS configuration for backscatter measurements described above, one or more parameters may be defined for mapping or associating Tx beams and corresponding uplink RS transmissions for backscatter measurements. The parameters may include, for example, a maximum duration and / or a maximum shift (eg, lateral and / or angular displacement) between a downlink channel (including SSB) measurement and a corresponding backscatter measurement for it to be counted.

[0160] In some embodiments, the WTRU may be configured with one or more parameters for performing reporting. The reporting may be configured as periodic, semi-persistent, or aperiodic reporting. For each of the reporting configurations, the parameters may include (but are not limited to): the number of reports (e.g., beam blockage rate or Rx signal strength); the index of the SSB (e.g., Tx beam) for which the report needs to be performed; the time-frequency resource, such as using PUCCH or PUSCH, which may include periodicity and offset, symbol index or starting symbol and number of contiguous symbols, PRB index or starting PRB and number of contiguous PRBs; frequency granularity (e.g., wideband versus subband configuration); one or more parameters associated with the measurement, such as a detection threshold; or N (i.e., the number of measurements used to obtain the average statistics).

[0161] The reporting configuration may be communicated to the WTRU, for example, in RRC signaling (e.g., via an RRC configuration message) or system information. Alternatively or additionally, a given reporting configuration may be activated or deactivated later by sending an activation or deactivation command using a downlink control channel (e.g., using downlink control information (DCI) scrambled or masked with the WTRU's RNTI).

[0162] Alternatively or in addition, the reporting of beam statistics for one or more Tx beams may be multiplexed with existing CSI reporting, where the WTRU is configured to send RSRP measurements to the network on one or more SSBs. For each of the configured gNB Tx beams (e.g., for which blockage statistics need to be captured), the WTRU may transmit RS on the configured resources and perform backscatter measurements. For example, the WTRU may measure the Rx signal strength or perform a cross-correlation with a known WTRU sequence. If the WTRU is configured to calculate beam blockage rate, the WTRU may take multiple measurements (e.g., equal to N) and use the multiple measurements to calculate an average statistic. The average statistic may be, for example, a simple average or median, or an exponential moving average. Based on the configuration, the WTRU may measure for the wideband and one or more sub-bands. The WTRU may send the resulting blockage statistics for each of the configured Tx beams on the configured resources for reporting.

[0163] The network (e.g., gNB / eNB / BS) may use the beam blocking statistics for each of the configured Tx beams received in the report from the WTRU to determine the best Tx beam for the WTRU, and in some embodiments, also the best Rx beam. For example, the network may use a metric that is a function of downlink RSRP and the beam blocking rate measured at the WTRU to select the best beam for that WTRU.

[0164] Also described herein are embodiments of network biased beam selection for sensor-assisted beam selection. WTRU Tx beam selection may be based on a combination of uplink signal quality (e.g., RSRP, etc.), JCS measurements performed by the WTRU, and a set of one or more bias values ​​configured at the WTRU. The WTRU may use the JCS backscatter measurements and the configured bias values ​​when determining the Tx beam on which the WTRU will transmit an RS (e.g., SRS) for uplink beam selection. The WTRU may use the JCS backscatter measurements or the configured bias values, or a combination of both, to filter out beams for evaluation of uplink transmissions.

[0165] The gNB may select a preferred WTRU Tx beam based on uplink signal quality measurements on a reduced number of beams used by the WTRU for uplink beam selection. The gNB may signal the preferred / selected WTRU Tx beam using an appropriate downlink channel configuration (e.g., DCI) in a downlink co-channel transmission (e.g., PDCCH).

[0166] A bias value may be configured for each WTRU Tx beam. The bias value may be determined based on one or more of: observed interference due to the WTRU Tx beam, current resource utilization on the corresponding gNB Rx beam, etc. The WTRU may combine the backscatter measurement and the individual bias values ​​for each beam using one of a number of possible alternatives, such as: sum, weighted sum, maximum, etc. For example, the WTRU may add multiple values ​​(e.g., two values) to determine the suitability of a particular beam for uplink transmission. If the calculated metric exceeds a configured threshold, the WTRU may skip RS transmission on the beam used for Tx beam selection. In some embodiments, each beam bias value and threshold may be communicated to the WTRU, for example, in system information or RRC configuration.

[0167] The WTRU may be configured with a single offset value for each beam. Alternatively or in addition, the WTRU may be configured with multiple offset values ​​for each beam. These values ​​may correspond to different traffic types or classes or physical channels. The WTRU may first select an appropriate offset value for each beam, for example, based on the intended application, while determining the final metric used to filter the Tx beams used for RS transmission.

[0168] In some embodiments, the WTRU may perform or support receive beam selection. Specifically, the WTRU may receive a configuration for a JCS reference signal (JCS-RS). The configuration may include, for example, a number of resource groups, a periodicity, and the like. The WTRU may also receive a JCS measurement report configuration, which may include, for example, a number of resource groups, a periodicity, a threshold, and the like. For each configured transmit beam, the WTRU may transmit a JCS-RS on or using the configured resources of a default resource group and measure the backscatter power on the corresponding receive beam. The WTRU may then calculate a beam blocking ratio, which may be defined as, for example, the ratio of the number of beams for which the received backscatter power exceeds a configured threshold to the total number of beams evaluated. The WTRU may report the beam blocking ratio on one of the configured resource groups. In the event that the beam blocking ratio differs from a previously reported value by more than a first threshold, the WTRU may select a different resource group, for example, with a different transmission periodicity, for subsequent JCS-RS transmissions. In the event that the beam blocking ratio differs from the previously reported value by a value exceeding a second threshold, the WTRU may select a different resource group, for example, with a different reporting periodicity, for the next report transmission.

[0169] In some embodiments, such as in network-biased WTRU uplink beam selection, the WTRU may use a combination of the bias value for each beam and the JCS measurement when prioritizing beams for uplink RS transmission for uplink Tx beam selection. A beam blocking rate report may be triggered if it exceeds a threshold.

[0170] Embodiments for sensing-based beam failure detection are described herein. The WTRU may perform JCS-like / radar measurements by transmitting a reference signal (e.g., SRS, DMRS, PTRS, or similar) and estimating the associated backscatter channel. The WTRU may estimate the channel impulse response using an estimation algorithm (e.g., least squares, etc.). Alternatively, relevant parameters of the channel impulse response (e.g., round-trip time (τ_r), path loss (γ), or delay spread (σ_τ) or similar parameters) are estimated by other means (e.g., maximum likelihood or similar means).

[0171] The WTRU may perform these measurements for a single transmit beam or multiple transmit beams and may store the measurements for receive beams based on various criteria (e.g., only the best Rx beam, or for each Tx / Rx beam pair, etc.). The WTRU may compare these estimated parameters against relevant threshold criteria for determining a measurement event. For example, a measurement event may occur when the path loss is below a certain threshold or the round trip time is within a critical range. The satisfaction of these determination criteria may indicate the occurrence of a JCS sensing event. Alternatively or in addition, a JCS sensing event may be determined by comparing JCS measurements for different beams and / or beam pairs. For example, it may be determined that the round trip travel time for the Tx / Rx beam pair (X, Y) is greater than the round trip travel time for the Tx / Rx beam pair (U, V). A sensing event may occur if a beam other than the serving beam has a metric of interest (e.g., backscatter channel gain) that indicates that the beam will provide better link performance than the current serving beam.

[0172] Alternatively or additionally, to limit excessive beam switching, a sensing event may occur if the measured performance exceeds a threshold, for example, if the backscatter channel gain is at least X dB below the backscatter channel gain on the current serving beam. A sensing event may be determined by a single measurement instance, or may utilize a combination or selection of the current measurement and previous beam measurements made for the same beam pair. For example, a sensing event may occur when the backscatter channel gain is X dB below the previous N JCS measurements performed for the Tx / Rx beam pair (U, V).

[0173] Figure 9An exemplary joint communication and sensing (JCS) measurement leading to a sensing event is depicted. In this example, a JCS measurement may be performed by the WTRU in two adjacent beams. When performing such measurements, the WTRU may estimate the path losses γ1 and γ2 for the two beams, respectively. For example, if the JCS measurement value 902 is greater than the detection threshold λ, the measurement may indicate that an object 901 has been detected, such as Figure 9 Alternatively or additionally, integrating the JCS measurement power observed on beam 1 and beam 2 may indicate an offset where the backscatter channel gain on beam 2 is lower than that of beam 1, which may indicate another sensing event.

[0174] Embodiments for sensing-based beam failure recovery initialization are described herein. A beam blocking event may be defined as the occurrence of a beam measurement that results in a backscatter channel gain estimate that is above a threshold. The threshold may be static or configurable (e.g., via RRC signaling, etc.). The threshold may depend on WTRU capabilities, which may be indicated by the WTRU, for example, in RRC signaling. The threshold may be determined by a quality requirement for transmitting and receiving data. The quality requirement may be, for example, a Quality of Service (QoS) Class Identifier (QCI) for a given bearer. A beam blocking event may be based on a single JCS measurement or may be based on a history of measurements taken. For example, the event may occur when a backscatter channel gain above a threshold is measured for N previous JCS measurements. The number of historical JCS measurements incorporated into the event determination may be static or configurable (e.g., via RRC signaling).

[0175] The WTRU may be configured to determine that a given beam is in beam failure if a beam blocking event occurs. A beam failure may be determined based on the occurrence of a single beam blocking event or multiple beam blocking events within a configured time range (e.g., N beam blocking events within the past Mms or similar time range). In some embodiments, such as when the serving gNB configures the WTRU to perform JCS measurements using SRS and / or JCS-RS transmission and reception, JCS measurements for beam failure detection may be performed on the configured reference signals. In some embodiments, such as when the WTRU observes backscatter channel gain from PDSCH DMRS, JCS measurements for beam failure detection may be performed using reference signals configured for other purposes. A blocking event may be determined based on a single RS transmission configuration (e.g., blocking determined by SRS backscatter) or based on a combination of multiple JCS measurement configurations (e.g., a combination of blocking detected using SRS transmission and PDSCH DMRS transmission). The WTRU may determine that a beam failure from a beam blocking event has occurred on a single beam (e.g., the serving beam) or on multiple beams, such as when a blocking event occurs on both the serving beam and a neighboring beam. The WTRU may determine a beam failure based solely on the beam blocking event or based on a combination of the beam blocking event and other events. For example, the WTRU may determine that a beam failure has occurred based on a combination of a beam blocking event and an out-of-range CQI estimated from the CSI-RS. The beam blocking event on a given WTRU beam may be configured by associating relevant beam parameters (e.g., via an RRC configuration message), associating a beam blocking event with a transmit / receive beam pair (e.g., a blocking event on a beam that is similarly co-located (QCL) with an active transmit / receive beam pair), or having the WTRU determine this autonomously.

[0176] Figure 10 An example state flow is shown in which a WTRU uses beam blocking events to determine beam failure. In this example, the WTRU may be configured with a beam blocking event counter, N, and a blocking window timer. When the WTRU observes a beam blocking event, as shown at 1010, the WTRU may increment the beam blocking counter and / or initiate a blocking window timer. If the blocking window timer expires before the beam blocking event counter reaches the configured number of beam blocking events, thereby indicating a beam failure, N, the beam blocking event counter may be decremented, as shown at 1020. If the beam blocking event counter reaches zero, as shown at 1030, the WTRU state may remain stable until, for example, a subsequent beam blocking event occurs. If the beam blocking counter meets the required N beam blocking events, the WTRU may determine that a beam failure has occurred, as shown at 1040, and initiate beam failure recovery.

[0177] Figure 11An exemplary scenario for initiating sensing-based beam failure recovery, also referred to as sensing-based beam detection failure initialization procedure, is depicted. Figure 11 As shown at 1110, the WTRU may perform N JSC RS transmissions and backscatter measurements using Layer 1 (L1) signaling. The N JSC RS transmissions may be performed at a periodicity 1115, which may be based on a maximum periodicity value (e.g., 2 ms, or the shortest periodicity between configured periodic failure detection resources). Based on the backscatter measurements, the WTRU may determine that a beam failure has occurred. In some embodiments, as shown, the WTRU may determine that a beam failure has been detected when a quality measurement (e.g., QCI, received signal strength, or another metric for a given bearer) is below an 'out-of-sync' threshold for all or a subset of the configured periodic resources. In some embodiments, the quality measurement may be expressed in terms of the number of beam failures, in which case a beam failure may be determined when such a measurement meets or exceeds a threshold. At 1120, in one or more instances as shown, the WTRU may indicate the failure detection to a MAC (L2 / L3) function or entity configured at the WTRU. The beam failure detection indication may occur based on one or more timing parameters, which may include a periodicity or offset value. After indicating a detected beam failure, the function may increment a beam failure detection counter. One or more beam failure detection timers may be configured at the function and may define a window 1130. If the window 1130 expires and the function has not received a beam failure detection, the beam failure detection counter may be set to zero. The WTRU may continue to perform JSC transmissions and backscatter measurements, and the WTRU may continue to increment the beam failure detection counter. In the event that the counter reaches or exceeds a maximum beam failure threshold, the WTRU may be configured to initiate beam failure recovery.

[0178] In some embodiments, the WTRU may implement a combined uplink and downlink based procedure where beam failure recovery is initialized when the combined metric of downlink beam quality and uplink quality is greater than a configured threshold. For example, the WTRU may initiate beam failure recovery when the sum of the number of beam failures detected in the downlink and the number of JCS measurements exceeding a certain value reaches a configured level.

[0179] Embodiments for sensing-based event reporting are described herein. A WTRU may be configured to report sensing-based measurements, for example, when a measurement report trigger has occurred. A base station (e.g., a gNB) may configure JCS sensing measurement reporting using parameters that configure the measurement to be event triggered. The event trigger configuration may include one or more relevant measurement parameters (e.g., backscatter channel gain, round trip time of signal backscatter, power delay profile, etc.). The measurement event may be based on the measurement parameter compared to a configured threshold. For example, the WTRU may determine whether the backscatter channel gain is greater than a threshold. The measurement event may be based on the measurement parameter compared to similar measurements observed on other beam pairs. For example, the WTRU may determine that the power delay profile of a neighboring beam is greater than the power delay profile of the serving beam by a certain offset. Measurement reporting may be configured for events that occur when the WTRU is in RRC connected mode (e.g., JCS measurements on dedicated WTRU resources) or when the WTRU is in RRC inactive / idle mode (e.g., performing autonomous JCS measurements in-band or out-of-band). The WTRU may determine an event trigger based on a single JCS measurement or a combination of JCS measurements history.

[0180] Embodiments for JCS-assisted beam failure detection are described herein. A WTRU may be configured for JCS-RS transmission using, for example, one or more parameters including a backscatter power threshold, a blocking count threshold (M), a maximum number of candidate uplink beams (P), and the like. The WTRU may transmit the JCS-RS using the configured resources and measure the backscatter power. In the event that the backscatter power exceeds the threshold M for a continuous time, the WTRU may switch to the next uplink beam and transmit the JCS-RS. In the event that the backscatter power of all P WTRU uplink beams exceeds the threshold M for a continuous time, the WTRU may initiate a beam failure recovery procedure. If the downlink channel quality is less than a first threshold N1 for a continuous time and the JCS backscatter power exceeds a second threshold N2 for a continuous time, the WTRU may switch to the next uplink beam.

[0181] While the examples described above may refer to technology-specific implementations (e.g., 5G NR), those skilled in the art will appreciate that the above concepts may be applicable to methods or systems implementing other wireless technologies, such as 3GPP Long Term Evolution (LTE) or IEEE 802. For example, the methods performed by a gNB in ​​conjunction with a WTRU could conceivably be performed by another form of base station (e.g., an eNodeB or other network node or AP) in conjunction with a UE, terminal, or station (STA).

[0182] In addition, although features and elements are described above in specific combinations, those skilled in the art will appreciate that each feature or element can be used alone or in combination with other features and elements. In addition, the methods described 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 include electronic signals (transmitted via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as internal hard disks and removable disks, magneto-optical media), and optical media such as CD-ROMs and digital versatile disks (DVDs). A processor in combination with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, STA, or any host computer.

Claims

1. A method performed by a wireless transmit / receive unit (WTRU), the method comprising: receiving configuration information indicating resources for receiving a first set of reference signals from one or more transmission / reception points (TRPs) using a first set of receive (Rx) beams, one or more resource groups for transmitting a second set of reference signals, and one or more resource groups for reporting sensing information of the transmitted second set of reference signals; transmitting the second set of reference signals in a plurality of spatial directions using one of the indicated one or more resource groups; measuring backscatter power of at least a portion of the transmitted second set of reference signals; reporting sensing information using one of the one or more resource groups for reporting sensing information based on the measured backscatter power of at least the portion of the transmitted second set of reference signals, the sensing information comprising information indicative of one or more blockage statistics associated with at least a portion of the plurality of spatial directions; as well as The first set of reference signals is received from the one or more TRPs using a second set of Rx beams, wherein the second set of Rx beams is determined based on the reported sensing information.

2. The method of claim 1 , further comprising determining another resource group of the one or more resource groups for transmitting a second set of reference signals based on the reported sensing information; and Another resource group among the one or more resource groups is used for reporting sensing information of the transmitted second set of reference signals.

3. The method of claim 2 , wherein the another resource group of the one or more resource groups for transmitting the second set of reference signals is determined based on a comparison between a measured backscatter power of each of at least the portion of the transmitted second set of reference signals and a threshold. 4 . The method of claim 2 , wherein the one or more blockage statistics comprise blockage rates associated with at least the portion of the plurality of spatial directions. 5 . The method according to claim 4 , wherein the another resource group among the one or more resource groups for transmitting the second set of reference signals is determined based on a comparison between the blocking rate and a threshold. The method according to claim 5 , wherein the sensing information is reported when the blocking rate exceeds the threshold. The method of claim 4 , wherein the second group of Rx beams is a subset of the first group of Rx beams.

8. The method of claim 2 , wherein the one of the one or more resource groups used to transmit the second set of reference signals is associated with a first transmission periodicity, wherein the other of the one or more resource groups used to transmit the second set of reference signals is associated with a second transmission periodicity, and wherein the first transmission periodicity and the second transmission periodicity are different.

9. The method of claim 2, wherein the one of the one or more resource groups for reporting sensing information is associated with a first reporting periodicity, wherein the other of the one or more resource groups for reporting sensing information is associated with a second reporting periodicity, and wherein the first reporting periodicity and the second reporting periodicity are different.

10. The method of claim 1 wherein the received configuration information includes information indicating a time offset between the reception of a message by the WTRU and a next transmission of one of the second set of reference signals.

11. A wireless transmit / receive unit (WTRU), the WTRU comprising: processor; and transceiver; The transceiver is configured to receive configuration information indicating resources for receiving a first set of reference signals from one or more transmission / reception points (TRPs) using a first set of receive (Rx) beams, one or more resource groups for transmitting a second set of reference signals, and one or more resource groups for reporting sensing information of the transmitted second set of reference signals; The transceiver is further configured to transmit the second set of reference signals in a plurality of spatial directions using one of the indicated one or more resource groups; The processor and the transceiver are configured to measure backscatter power of at least a portion of the transmitted second set of reference signals; The processor and the transceiver are further configured to report sensing information using one of the one or more resource groups for reporting sensing information based on the measured backscatter power of at least the portion of the transmitted second set of reference signals, the sensing information comprising information indicative of one or more blockage statistics associated with at least a portion of the plurality of spatial directions; and The transceiver is further configured to receive the first set of reference signals from the one or more TRPs using a second set of Rx beams, wherein the second set of Rx beams is determined based on the reported sensing information.

12. The WTRU of claim 11 , wherein the processor is further configured to determine based on the reported sensing information: another resource group of the one or more resource groups for transmitting a second set of reference signals; and Another resource group among the one or more resource groups is used for reporting sensing information of the transmitted second set of reference signals.

13. The WTRU of claim 12 , wherein the other resource group of the one or more resource groups used to transmit the second set of reference signals is determined based on a comparison between a measured backscatter power of each of at least the portion of the transmitted second set of reference signals and a threshold.

14. The WTRU of claim 12, wherein the one or more blocking statistics include blocking rates associated with at least the portion of the plurality of spatial directions.

15. The WTRU of claim 14, wherein the another resource group of the one or more resource groups used for transmitting the second set of reference signals is determined based on a comparison between the blocking rate and a threshold.

16. The WTRU of claim 15, wherein the sensing information is reported when the blocking rate exceeds the threshold.

17. The WTRU of claim 14, wherein the second set of Rx beams is a subset of the first set of Rx beams.

18. The WTRU of claim 12, wherein the one of the one or more resource groups used to transmit the second set of reference signals is associated with a first transmission periodicity, wherein the other of the one or more resource groups used to transmit the second set of reference signals is associated with a second transmission periodicity, and wherein the first transmission periodicity and the second transmission periodicity are different.

19. The WTRU of claim 12, wherein the one of the one or more resource groups for reporting sensing information is associated with a first reporting periodicity, wherein the other of the one or more resource groups for reporting sensing information is associated with a second reporting periodicity, and wherein the first reporting periodicity and the second reporting periodicity are different.

20. The WTRU of claim 11 wherein the received configuration information includes information indicating a time offset between the reception of a message by the WTRU and a next transmission of one of the second set of reference signals.

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