Methods and apparatus for synchronization signal block to RACH occasion mapping in sub-band non-overlapping full duplex systems

Abstract

Methods and apparatuses are described for synchronization signal block to random access channel (RACH) occasion mapping in sub-band non-overlapping full duplex systems are described. Methods include receiving configuration information including a set of synchronization signal block (SSB) indexes, wherein the set of SSB indexes includes a first subset of SSB indexes and a second subset of SSB indexes; receiving an indication that the second subset of SSB indexes are valid for sub-band non-overlapping full duplex (SBFD) random access channel (RACH) opportunities (ROs); mapping the second subset of SSB indexes to SBFD ROs in ascending order of RO indexes and in descending order of SSB indexes; selecting either an RO associated with the first subset of SSB indexes or an RO associated with the second subset of SSP indexes; and transmitting a physical random access channel (PRACH) preamble using the selected RO.

Description

METHODS AND APPARATUS FOR SYNCHRONIZATION SIGNAL BLOCK TO RACH OCCASION MAPPING IN SUB-BAND NON-OVERLAPPING FULL DUPLEX SYSTEMSCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 572,725 filed in the U.S. Patent and Trademark Office on April 1 , 2024, the entire content of which being incorporated herein by reference as if fully set forth below in its entirety and for all applicable purposes.SUMMARY

[0002] In embodiments, a method is performed by a first wireless transmit / receive unit (WTRU), the method may include: receiving configuration information including a set of synchronization signal block (SSB) indexes, wherein the set of SSB indexes includes a first subset of SSB indexes and a second subset of SSB indexes; receiving an indication that the second subset of SSB indexes are valid for sub-band non-overlapping full duplex (SBFD) random access channel (RACH) opportunities (ROs); mapping the second subset of SSB indexes to SBFD ROs in ascending order of RO indexes and in descending order of SSB indexes; selecting either an RO associated with the first subset of SSB indexes or an RO associated with the second subset of SSP indexes; and transmitting a physical random access channel (PRACH) preamble using the selected RO. Additionally / altematively, the WTRU is configured to indicate SBFD capability using an SBFD RO. Additionally / altematively, the selection of RO is based on the selected RO being an earliest RO in time. Additionally / altematively, wherein the selection of RO is based on the RO being within a predetermined number of time resources after a non-SBFD RO in time. Additionally / altematively, the selection of the RO is based on when the WTRU determines to transmit the PRACH preamble. Additionally / altematively, the WTRU selects the SSB during and initial access procedure or as part of a beam failure recovery (BFR) procedure. Additionally / altematively, the WTRU selects the SSB based on a measured received power. Additionally / altematively, the WTRU connects to a cell using the selected SSB. Additionally / altematively, the configuration information includes RACH configurations that include a number of ROs that can be mapped in a frequency domain. Additionally / altematively, the configuration information further comprises a second RACH configuration and further comprising determining a second set of valid ROs and corresponding SSB to RO mapping based on the second RACH configuration.

[0003] In embodiments, a wireless transmit / receive unit (WTRU) includes: a transceiver; and a processor; wherein the transceiver and processor are configured to: receive configuration information including a set of synchronization signal block (SSB) indexes, wherein the set of SSB indexes includes a first subset of SSB indexes and a second subset of SSB indexes; receive an indication that the second subset of SSB indexes are valid for sub-band non-overlapping full duplex (SBFD) random access channel (RACH) opportunities (ROs); map the second subset of SSB indexes to SBFD ROs in ascending order of RO indexes and in descendingorder of SSB indexes; select either an RO associated with the first subset of SSB indexes or an RO associated with the second subset of SSP indexes; and transmit a physical random access channel (PRACH) preamble using the selected RO. Additionally / alternatively, the transceiver and processor are further configured to indicate SBFD capability using an SBFD RO. Additionally / alternatively, the selection of RO is based on the selected RO being an earliest RO in time. Additionally / alternatively, the selection of RO is based on the RO being within a predetermined number of time resources after a non-SBFD RO in time. Additionally / alternatively, the selection of the RO is based on when the processor determines to transmit the PRACH preamble. Additionally / alternatively, the transceiver and processor are further configured to select the SSB during an initial access procedure or as part of a beam failure recovery (BFR) procedure. Additionally / alternatively, the transceiver and processor are further configured to select the SSB based on a measured received power. Additionally / alternatively, the transceiver and processor are further configured to connect to a cell using the selected SSB. Additionally / alternatively, the configuration information includes RACH configurations that include a number of ROs that can be mapped in a frequency domain. Additionally / alternatively, an earliest valid RO corresponding to the selected SSB is in a non-SBFD time resource and the SBFD time resource is within a threshold number of time resources after the non-SBFD time resource.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, wherein like reference numerals in the figures indicate like elements, and wherein:

[0005] FIG. 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented;

[0006] FIG. 1 B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A according to an embodiment;

[0007] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A according to an embodiment;

[0008] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1A according to an embodiment;

[0009] FIG. 2 is an example diagram of SBFD configuration in a TDD framework;

[0010] FIG. 3 is an example diagram of SSB-to-RO mapping;

[0011] FIG. 4 is an example diagram of joint SSB-RO mapping in SBFD and non-SBFD ROs;

[0012] FIG. 5 is an example RRC configuration;

[0013] FIG. 6 is an example diagram of SSB-to-RO mapping for N = 4;

[0014] FIG. 7 is an example diagram of separate SSB-RO mapping in SBFD and non-SBFD Rs;

[0015] FIG. 8 is an example diagram of joint SSB-RO mapping in SBFD and non-SBFD ROs;

[0016] FIG. 9 is a further example diagram of joint SSB-RO mapping in SBFD and non-SBFD ROs;

[0017] FIG. 10 is a further example diagram of joint SSB-RO mapping in SBFD and non-SBFD ROs;

[0018] FIG. 11 is a further example diagram of joint SSB-RO mapping in SBFD and non-SBFD ROs; and

[0019] FIG. 12 is an example flow diagram of a process for SSB-to-RO mapping in SBFD systems.DETAILED DESCRIPTION

[0020] FIG. 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 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), singlecarrier FDMA (SC-FDMA), zero-tail unique-word discrete Fourier transform Spread OFDM (ZT-UW-DFT-S- OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0021] As shown in FIG. 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (ON) 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though 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 a user equipment (WTRU), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fl device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a WTRU.

[0022] The com munications systems 100 may also incl ude 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 leastone 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 the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a NodeB, an eNode B (eNB), a Home Node B, a Home eNode B, a next generation NodeB, such as a gNode B (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] The 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, and the like. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as 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 coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

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

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

[0028] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by 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., an eNB and a gNB).

[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 EDGE (GERAN), and the like.

[0030] The base station 114b in FIG. 1A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the 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. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, 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 be utilizing a NR radio technology, the CN 106 may also be incommunication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0032] The CN 106 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide 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), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications 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 communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellularbased radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0034] FIG. 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining 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 association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), any other type of integrated circuit (IC), a state machine, and the like. 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. While FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

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

[0037] Although the transmit / receive element 122 is depicted in FIG. 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0038] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are 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 for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11 , for example.

[0039] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and 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 and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li- ion), etc.), solar cells, fuel cells, and the like.

[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 over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0042] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors. The sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, a humidity sensor and the like.

[0043] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the 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 to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the DL (e.g., for reception)).

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

[0045] The RAN 104 may include eNode-Bs 160a, 160b, 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, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 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, and the like. As shown in FIG. 10, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0047] The CN 106 shown in FIG. 1C 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 aredepicted 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 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 the S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts 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 communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0052] Although the WTRU is described in FIGS. 1A-1 D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0053] In representative embodiments, 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 or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (I BSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad-hoc” mode of communication.

[0055] When using the 802.11ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 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 the 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 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0056] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0057] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two noncontiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0058] Sub 1 GHz modes of operation are supported by 802.11 af and 802.11ah. The channel operating bandwidths, and carriers, are reduced in 802.11af and 802.11ah relative to those used in 802.11n, and 802.11ac. 802.11af supports 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 Communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limitedbandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0059] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 n, 802.11ac, 802.11af, and 802.11ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all ST As in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode) transmitting to the AP, all available frequency bands may be considered busy even though a majority of the available frequency bands remains idle.

[0060] In the United States, the available frequency bands, which may be used by 802.11 ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0061] FIG. 1D is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an 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, 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, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, 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 an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

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

[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 the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non- standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0065] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, DC, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0066] The CN 106 shown in FIG. 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and 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 in the RAN 104 via an N2 interface 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, support for network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of non-access stratum (NAS) signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB)access, services for MTC access, and the like. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0068] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 106 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 106 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating WTRU IP address, managing PDU sessions, controlling policy enforcement and QoS, providing DL data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0069] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The 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. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local DN 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0071] In view of FIGs. 1A-1 D, and the corresponding description of FIGs. 1A-1 D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0072] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device maybe directly coupled to another device for purposes of testing and / or performing testing using over-the-air wireless communications.

[0073] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0074] Acronyms and abbreviations as used in the preceding and following paragraphs may be defined as follows:ACK Acknowledgement AoA Angle of Arrival AoD Angle of Departure ARFCN Absolute Radio-Frequency Channel Number BLER Block Error Rate BW Bandwidth BWP Bandwidth Part CAP Channel Access Priority CAPC Channel access priority class CBR Channel Busy Ratio CCA Clear Channel Assessment CCE Control Channel Element CE Control Element CG Configured Grant or Cell Group CORESET Control Resource Set CP Cyclic Prefix CP-OFDM Conventional OFDM (relying on cyclic prefix) CQI Channel Quality Indicator CRC Cyclic Redundancy Check CSI Channel State Information cw Contention Window cws Contention Window Size co Channel Occupancy DAI Downlink Assignment Index DCI Downlink Control Information DFI Downlink feedback information DG Dynamic grant DL Downlink DM-RS Demodulation Reference Signal DRB Data Radio Bearer DRX Discontinuous Reception ECID Enhanced Cell ID eLAA enhanced Licensed Assisted Access eMBB enhanced Mobile BroadbandFeLAA Further enhanced Licensed Assisted AccessHARQ Hybrid Automatic Repeat RequestIM Interference MeasurementLAA License Assisted Access LBT Listen Before Talk LCH Logical Channel LCP Logical Channel Priority LBT Listen-Before-Talk LOS Line of Sight NLOS Non Line of Sight LMF Location Management Function LPP LTE Positioning Protocol LTE Long Term Evolution e.g. from 3GPP LTE R8 and up MAC CE MAC Control Element MAC Medium Access Control MCS Modulation and Coding Scheme MIMO Multiple Input Multiple Output NACK Negative ACK NAS Non-access stratum NR New Radio OFDM Orthogonal Frequency-Division Multiplexing OTDOA Observed Time Difference of Arrival PDCCH Physical Downlink Control Channel PDSCH Physical Downlink Shared Channel PDU Packet Data Unit PHY Physical Layer PID Process ID PO Paging Occasion PRACH Physical Random Access Channel PRS Positioning Reference Signal PRU Positioning Reference Unit PSFCH Physical Sidelink Feedback Channel PSS Primary Synchronization Signal PTRS Phase Tracking Reference Signal PUCCH Physical Uplink Control Channel PUSCH Physical Uplink Shared Channel RA Random Access (or procedure) RACH Random Access Channel RAR Random Access Response RCU Radio access network Central Unit RE Resource Element RF Radio Front end RLF Radio Link Failure RLM Radio Link Monitoring RNTI Radio Network Identifier RNA RAN Notification Area RO RACH occasion RRC Radio Resource Control RRM Radio Resource Management RTT Round Trip Time RP Reception Point RS Reference Signal RSRP Reference Signal Received Power RSTD Reference Signal Time Difference RTT Round Trip Time RSSI Received Signal Strength Indicator RTOA Relative Time of ArrivalSDAP Service data adaptation protocolSDU Service Data UnitSRB Signaling Radio BearerSRS Sounding Reference SignalSS Synchronization SignalSSS Secondary Synchronization SignalSWG Switching Gap (in a self-contained subframe)SPS Semi-persistent schedulingSUL Supplemental UplinkTB Transport BlockTBS Transport Block SizeTDoA Time Difference of ArrivalTRP Transmission-Reception PointTSC Time-sensitive communicationsTSN Time-sensitive networkingTTI Transmission Time IntervalUCI Uplink Control InformationUL UplinkURLLC Ultra-Reliable and Low Latency CommunicationsWBWP Wide Bandwidth PartWLAN Wireless Local Area Networks and related technologies (IEEE 8O2.xx domain)WTRU Wireless Transmit / Receive Unit

[0075] Conventional time division duplex (TDD) is based on splitting the time domain between the uplink and downlink. Wireless communications systems may operate full duplex, and specifically, sub-band nonoverlapping full duplex (SBFD) at a base station gNB within a conventional TDD band. An example is shown in FIG. 2, which comprises a downlink slot 210, SBFD slots 212, a flexible slot 214 and an uplink slot 216.

[0076] Reducing the latency in accessing and connecting to the network is a key benefit that can be achieved by using SBFD. A WTRU may be configured with random access channel (RACH) occasions (RO) in the time and frequency domains. In TDD, the ROs are only valid if they coincide with uplink slots in the time domain, and the WTRU avoids physical random access channel (PRACH) transmission if the ROs are in downlink slots.

[0077] In some systems RO allocations may be valid only in uplink slots and SSB-to-RO mapping is in the order of frequency, time, and then RO slots, as shown in an example in FIG. 3. FIG. 3 shows downlink slots 310, 312, 314; flexible slot 316, a first uplink slot 318 and a next uplink slot 320. In the case of SBFD ROs, more ROs may be available as part of SBFD ROs that can be used by WTRUs. In some cases, SSB-RO mapping may need enhancements. In cases where ROs may map to SBFD and non-SBFD symbols, the SSB- to-RO mappings need enhancements.

[0078] Operation of SBFD-capable WTRUs with additional available ROs is described herein.

[0079] Methods for SSB-to-RO mapping types in SBFD systems are described. In some embodiments, an SBFD-capable WTRU may receive an indication on the subset of configured SSBs that can be used for SBFD operation, where the WTRU considers the indicated subset of SSBs for SSB-to-RO mapping. The subset may be used to enable beam nulling or UL muting for cross-link interference (CLI) mitigation. In embodiments, forthe SSBs in the allowed subset, the network may increase the opportunities for PRACH transmission, which can reduce latency and collisions for PRACH transmission. In embodiments, these extra ROs may also be used for PRACH repetition to support coverage enhancement with reduced latency.

[0080] Herein, the terms PRACH occasion, random access occasion, and RO may be used interchangeably.

[0081] Terms used herein are described below.

[0082] The term “beam” as used herein is described below.

[0083] In embodiments, a WTRU may transmit or receive a physical channel or reference signal according to at least one spatial domain filter. The term “beam” may be used to refer to a spatial domain filter.

[0084] In embodiments, a WTRU may transmit a physical channel or signal using the same spatial domain filter as the spatial domain filter used for receiving an RS (such as CSI-RS) or a SS block. The WTRU transmission may be referred to as “target”, and the received RS or SS block may be referred to as “reference” or “source”. In such a case, the WTRU may be said to transmit the target physical channel or signal according to a spatial relation with a reference to such RS or SS block.

[0085] In embodiments, a WTRU may transmit a first physical channel or signal according to the same spatial domain filter as the spatial domain filter used for transmitting a second physical channel or signal. The first and second transmissions may be referred to as “target” and “reference” (or “source”), respectively. In such case, the WTRU may be said to transmit the first (target) physical channel or signal according to a spatial relation with a reference to the second (reference) physical channel or signal.

[0086] A spatial relation may be implicit, configured by RRC or signaled by MAC CE or DCI. For example, a WTRU may implicitly transmit PUSCH and DM-RS of PUSCH according to the same spatial domain filter as an SRS indicated by an SRI indicated in DCI or configured by RRC. In another example, a spatial relation may be configured by RRC for an SRS resource indicator (SRI) or signaled by MAC CE for a PUCCH. Such spatial relation may also be referred to as a “beam indication”.

[0087] In embodiments, a WTRU may receive a first (target) downlink channel or signal according to the same spatial domain filter or spatial reception parameter as a second (reference) downlink channel or signal. For example, such association may exist between a physical channel such as PDCCH or PDSCH and its respective DM-RS. At least when the first and second signals are reference signals, such association may exist when the WTRU is configured with a quasi-colocation (QCL) assumption type D between corresponding antenna ports. Such association may be configured as a TCI (transmission configuration indicator) state. A WTRU may be indicated an association between a CSI-RS or SS block and a DM-RS by an index to a set of TCI states configured by RRC and / or signaled by MAC CE. Such indication may also be referred to as a “beam indication”.

[0088] The terms TRP, MTRP, M-TRP as used herein are described below.

[0089] Hereafter, a TRP (e.g., transmission and reception point) may be interchangeably used with one or more of TP (transmission point), RP (reception point), RRH (radio remote head), DA (distributed antenna), BS (base station), a sector (of a BS), and a cell (e.g., a geographical cell area served by a BS), but still consistent with this invention. Hereafter, Multi-TRP may be interchangeably used with one or more of MTRP, M-TRP, and multiple TRPs, but still consistent with this invention.

[0090] The term subband as used herein is described below.

[0091] Hereinafter, the term “subband” and / or “sub-band” is used to refer to a frequency-domain resource and may be characterized by at least one of the following: a set of resource blocks (RBs); a set of resource block sets (RB sets), e.g. when a carrier has intra-cell guard bands; a set of interlaced resource blocks; a bandwidth part, or portion thereof; a carrier, or portion thereof. In embodiments, a subband may be characterized by a starting RB and number of RBs for a set of contiguous RBs within a bandwidth part. A subband may also be defined by the value of a frequency-domain resource allocation field and bandwidth part index.

[0092] The term XDD as used herein is described below.

[0093] Hereinafter, the term “XDD” is used to refer to a subband-wise duplex (e.g., either uplink ordownlink being used per subband) and may be characterized by at least one of the following: Cross Division Duplex (e.g., subband-wise FDD within a TDD band); Subband non-overlapping full duplex (SBFD); Subband-based full duplex (e.g., full duplex as both UL and DL are used / mixed on a symbol / slot, but either UL or DL being used per subband on the symbol / slot); Frequency-domain multiplexing (FDM) of DL / UL transmissions within a TDD spectrum; full duplex other than a same-frequency (e.g., spectrum sharing, subband-wise-overlapped) full duplex; or an advanced duplex method, e.g., other than (pure) TDD or FDD.

[0094] The term Dynamic / flexible TDD as used herein is described below.

[0095] Hereinafter, the term “dynamic( / flexible) TDD” is used to refer to a TDD system / cell which may dynamically (and / or flexibly) change / adjust / switch a communication direction (e.g., a downlink, an uplink, or a sidelink, etc.) on a time instance (e.g., slot, symbol, subframe, and / or the like). In an example, In a system employing dynamic / flexible TDD, a component carrier(CC) or a bandwidth part (BWP) may have one single type among ‘D’, ‘U’, and ‘F’ on a symbol / slot, based on an indication by a group-common(GC)-DCI (e.g., format 2_0) comprising a slot format indicator (SFI), and / or based on tdd-UL-DL-config-common / dedicated configurations. On a given time instance / slot / symbol, a first gNB (e.g., cell, TRP) employing dynamic / flexible TDD may transmit a downlink signal to a first WTRU being communicated / associated with the first gNB based on a first SFI and / or tdd-UL-DL-config configured / indicated by the first gNB, and a second gNB (e.g., cell, TRP) employing dynamic / flexible TDD may receive an uplink signal transmitted from a second WTRU being communicated / associated with the second gNB based on a second SFI and / or tdd-UL-DL-config configured / indicated by the second gNB. In an example, the first WTRU may determine that the reception ofthe downlink signal is being interfered by the uplink signal, where the interference caused by the uplink signal may refer to a WTRU-to-WTRU cross-layer interference (CLI).

[0096] Herein, downlink reception may be used interchangeably with Rx occasion, PDCCH, PDSCH, SSB reception.

[0097] Herein, uplink transmission may be used interchangeably with Tx occasion, PUCCH, PUSCH, PRACH, SRS transmission.

[0098] Herein, time instance, slot, symbol, and subframe may be used interchangeably, but still consistent with this invention.

[0099] Herein, uplink-only and downlink-only Tx / Rx occasions may interchangeably be used with legacy TDD uplink or legacy TDD downlink, respectively. In an example, the legacy TDD uplink transmission or legacy downlink reception occasions are the cases where SBFD is not configured and / or where SBFD is disabled.

[0100] Herein, the terms received signal power, received signal energy, received signal strength, SSB EPRE, CSI EPRE, RSRP, RSSI, SINR, RSRQ, SS-RSRP, SS-RSSI, SS-SINR, SS-RSRQ, CSI-RSRP, CSI- RSSI, CSI-SINR, and CSI-RSRQ may be used interchangeably.

[0101] Herein, the term CLI (cross-link interference) may be used interchangeably with interference.

[0102] Herein, the term non-SBFD may be used interchangeably with operation without SBFD, TDD, legacy TDD.

[0103] Herein, the terms “paired spectrum” and FDD may be used interchangeably.

[0104] Herein, the terms “unpaired spectrum” and TDD may be used interchangeably.

[0105] Herein, the terms “WTRU is configured,” “WTRU is indicated,” ‘WTRU receives configuration,” and so forth, may imply that the configuration is indicated for example via RRC, MAC-CE, DCI, MIB, SIB, and so forth, unless indicated otherwise, where for example, “WTRU is configured” may imply “WTRU is configured via RRC, MAC-CE, MIB, SIB” and so forth.

[0106] Herein, the terms PRACH, RACH, random-access, random-access occasion, RACH occasion, PRACH transmission, RACH transmission, RA, and RO, may be used interchangeably.

[0107] Embodiments described here may be applied to determination of different types of occasions that are determined in association with SSB mapping. The solutions may be used for determining SSB-to-RO mapping for PRACH preamble (e.g., Msg1) transmission. The solutions may be used for determining PUSCH Occasions (PO) in SSB-to-PO mapping for random access PUSCH (e.g., Msg A) transmission. The solutions may be used for determining PUSCH Occasions for mapping a number of valid PUSCH occasions for PUSCH transmissions over an association period, for example for configured grant Type 1 PUSCH transmissions on the initial UL BWP (e.g., for Small Data Transmission (SDT)).

[0108] In embodiments, a WTRU may receive a configuration or indication of transmitted SSB indexes (e.g., which indicates which SSBs are actually being transmitted), for example via ssb-PositionsInBurst (e.g.,via SIB 1 or RRC). The WTRU may then select an SSB (e.g., during initial access or BFR). The WTRU may then receive configuration information including a first RACH configuration (e.g., for legacy ROs) and a second (e.g., supplementary) RACH configuration (e.g., for SBFD ROs). The WTRU may then receive an indication (e.g., SBFD-SSB-subset) that indicates a subset of the transmitted SSBs (e.g., SSB indexes) that can be used for random access (RA) in an SBFD time resource (e.g., slot). In embodiments, the indicated SBFD-SSB- subset may be in the form of a bitmap. The value 0 may indicate that the corresponding SSB cannot be used for RA in an SBFD time resource, the value 1 may indicate that corresponding SSB can be used for RA in an SBFD time resource. The WTRU may then determine valid non-SBFD ROs and a corresponding SSB-to-RO mapping for the transmitted SSBs. For example, the WTRU may determine a first set of valid ROs (e.g., non- SBFD ROs) based on the first RACH configuration and maps the SSB indexes of the transmitted SSBs (e.g., provided by ssb-Positions / nBurst) to the valid non-SBFD ROs in increasing order of SSB index. Based on the received SSB subset indication, the WTRU may determine valid SBFD ROs and a corresponding SSB-to-RO mapping for the indicated SBFD SSB subset that can be used in an SBFD time resource. In embodiments, a WTRU may determine a second set of ROs (e.g., supplementary or SBFD ROs) based on the second RACH configuration and maps the SSB indexes in the SBFD SSB subset to the valid supplementary or SBFD ROs, for example in ascending order of RO index, and for example in descending order of SSB indexes from the highest SSB index in the SBFD SSB subset, as shown, for example in FIG. 4. The diagram 400 in FIG, 4 shows: a DL slot 410, SBFD slots 412, 414 and 415 each comprising four RO’s and UL slot 418, comprising eight RO’s. The example of FIG. 4 further shows that next SBFD slot would comprise SSB 10, 9 etc. and next UL slot would comprise SSB 5, 6 etc.

[0109] In embodiments, based on one or both of the determined SSB-to-RO mappings, when the selected SSB is in the SBFD SSB subset, the WTRU may select a valid RO corresponding to the selected SSB from an (e.g., the earliest) SBFD time resource that includes one or more valid SBFD ROs corresponding to the selected SSB when, for example, one or more of the following applies: (a) The WTRU is configured to indicate its SBFD capability using an SBFD RO; (b) The SBFD time resource is earlier than the next (e.g., earliest) non-SBFD time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB; (c) The earliest valid RO(s) corresponding to the SSB are in a non-SBFD time resource and the SBFD time resource is within a threshold number of time resources after the non-SBFD time resource (e.g., this may reduce collisions in the non-SBFD ROs); or (d)Timing (e.g., next, earlier, earliest) may be with respect to when the WTRU determines to perform a PRACH preamble transmission.

[0110] Alternatively to the embodiments described in the above-stated paragraph, in embodiments, based on one or both of the determined SSB-to-RO mappings, when the selected SSB is in the SBFD SSB subset, the WTRU may select a valid RO corresponding to the selected SSB from a non-SBFD time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB when the non-SBFD time resource is the earliest time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB. In embodiments, the WTRU may then transmit a PRACH preamble using the selected RO.

[0111] Subband non-overlapping full duplex (SBDF) operation is described below.

[0112] In embodiments, a WTRU may be configured with one or more types of slots within a bandwidth, wherein a first type of slot may be used or determined for a first direction (e.g., downlink); a second type of slot may be used or determined for a second direction (e.g., uplink); a third type of slot may have a first group of frequency resources within the bandwidth for a first direction and a second group of frequency resources within the bandwidth for a second direction.

[0113] Herein, the following terms apply: bandwidth may be interchangeably used with bandwidth part (BWP), carrier, subband, and system bandwidth; the first type of slot (e.g., the slot for a first direction) may be referred to as downlink slot; the second type of slot (e.g., slot for a second direction) may be referred to as uplink slot; the third type of slot may be referred to as Sub-Band (non-overlapping) Full Duplex (SBFD) slot; the group of frequency resource for a first direction may be referred to as downlink subband, downlink frequency resource, or downlink RBs; the group of frequency resource for a second direction may be referred to as uplink subband, uplink frequency resource, or uplink RBs; the group of frequency resource for a flexible direction (e.g., that can be configured fora first direction, second direction, etc.) may be referred to as flexible subband, flexible frequency resource, or flexible RBs; and the group of frequency resource between a first direction and a second direction may be referred to as guard band, guard frequency resource, or guard RBs.

[0114] In embodiments, a SBFD-enabled WTRU may receive or be configured with one or more SBFD uplink or downlink subbands in one or more downlink, uplink, and / or flexi ble TDD time instances (e.g., symbols, slots, frames, and so forth). The WTRU may be configured with one or more resource allocations for SBFD subbands. For example, the SBFD configuration may include a flag signal (e.g., enabled / disabled), where for example a first value (e.g., zero (0)) indicates a first mode of operation (e.g., SBFD configuration), and a second value (e.g., one (1)) may indicate a second mode of operation (e.g., non-SBFD operation). The modes of operation (e.g., SBFD or non-SBFD) may be indicated via, for example MIB, SIB, RRC, MAC-CE, DCI, and so forth.

[0115] In embodiments, the WTRU may receive the time resources (e.g., one or more symbols, slots, and so forth), for which the first mode of operation (e.g., SBFD) is defined in for example one or more BWPs, subbands, component carriers (CC), cells, and so forth. The WTRU may receive the frequency resources (e.g., subbands, BWPs, etc. including one or more PRBs) within (active and / or linked) BWP, for which the first mode of operation (e.g., SBFD) is configured. The time instances (e.g., slots, symbols) may be indicated based on periodic, semi-persistent, or aperiodic configurations. In an example, the time instances may be indicated via a bitmap configuration, where each bit corresponds to a time instance (e.g., slot, symbol, subframe, etc.) and each bit indication indicates whether corresponding time instance can be used for the first or second mode of operation.

[0116] In embodiments, a WTRU may be configured with a DL TDD configuration for a component carrier (CC) or a BWP for one or more Rx occasions (e.g., via tdd-UL-DL-config-common, dedicated configurations,slot format indicator (SFI), and so forth). As such, if the first mode of operation (e.g., SBFD) is configured, one or more of the configured frequency resources (e.g., subbands, PRBs, and / or BWPs) may be configured for the transmission in UL channels and / or Tx occasions.

[0117] In embodiments, a WTRU may be configured with an UL TDD configuration for a component carrier (CC) or a BWP for one or more Tx occasions (e.g., via tdd-UL-DL-config-common, dedicated configurations, slot format indicator (SFI), and so forth). As such, if the first mode of operation (e.g., SBFD) is configured, one or more of the configured frequency resources (e.g., subbands, PRBs, and / or BWPs) may be configured as the DL channels and / or Rx occasions.

[0118] In embodiments, the WTRU may be configured with a DL, UL, or Flexible TDD configuration for a component carrier (CC) or a BWP for one or more Rx / Tx occasions (e.g., via tdd-UL-DL-config-common, dedicated configurations, slot format indicator (SFI), and so forth). As such, if the first mode of operation (e.g., SBFD) is configured, one or more of the configured frequency resources (e.g., subbands, PRBs, and / or BWPs) may be configured for the first mode of operation (e.g., either UL transmission or DL reception based on the configurations).

[0119] In embodiments, the duplexing mode for the first mode of operation (e.g., SBFD configuration (UL / DL)) may be indicated via a flag indication, where for example a first value (e.g., zero (0)) may indicate a first direction (e.g., UL duplexing mode), and a second the value (e.g., one (1)) may indicate a second direction (e.g., DL duplexing model). The duplexing mode configuration and / or flag for the first mode of operation (e.g., SBFD) may be configured as part of modes of operation configuration, for example via MIB, SIB, RRC, DCI, MAC-CE, etc. The duplexing mode configuration and / or flag for the first mode of operation (e.g., SBFD) may be configured as part of resource allocation configuration for a Tx / Rx occasion.

[0120] In embodiments, a WTRU may be configured with one or more types of slots. The WTRU may be configured with a first slot with a first type, where the first type may be for example SBFD slot. The WTRU may be configured with a second slot with a second type, where the second type may be for example non-SBFD slot. As for the first slot with the first type (SBFD), the WTRU may be configured with one or more DL, UL, flexible, guard, etc. subbands in the frequency domain, throughout the BWP, for the duration of the first slot. However, in the second slot with the second type (non-SBFD), the WTRU may be configured with only one direction type, for example DL, UL, flexible, etc., in the frequency domain, throughout the BWP, for the duration of the second slot.

[0121] In embodiments, if the WTRU is configured with a second slot with UL direction, this implies legacy TDD UL slot, UL-only slot, and / or non-SBFD UL slot. In another example, if the WTRU is configured with a third slot with second type (non-SBFD) with DL direction, this implies legacy TDD DL slot, DL-only slot, and / or non-SBFD DL slot. In another example, if the WTRU is configured with a fourth slot with second type (non- SBFD) with flexible direction, this implies legacy TDD flexible slot and / or non-SBFD flexible slot, and so forth.

[0122] RACH configurations are described below.

[0123] In embodiments, a WTRU may receive, identify, or be configured the time domain resource allocations for one or more (e.g., consecutive) RACH Occasions (RO) based on the higher-layer parameter prach-Configurationlndex, or by msgA-PRACH-Configurationlndex, if configured. These parameters denote the PRACH configuration index corresponding to one or more tables that include random access parameters.

[0124] The WTRU may be configured with one or more of the following parameters:

[0125] In embodiments, the WTRU may be configured with a preamble format. For example, the WTRU may be configured with preamble format that may refer to one of the possible formats, namely: A1 , A2, A3, B1 , A1 / B1, A2 / B2, A3 / B3, B4, CO, C2. The preamble format may identify the corresponding Cyclic Prefix (CP) duration, sequence part duration, guard time duration (if applicable), etc.;

[0126] In embodiments, the WTRU may be configured with a frame number, subframe number, and / or slot number. For example, the WTRU may be configured with time-domain allocations, subframe number, and / or slot numbers during which the ROs may be configured. Using this parameter, the WTRU may determine the RO slot, for example within the corresponding subframe, where the WTRU may transmit the configured PRACH in one or more of the determined ROs; Starting symbol. For example, the WTRU may determine the symbollevel index corresponding to the starting position of the first RO transmission within the indicated and / or configured RO slot.

[0127] In embodiments, the WTRU may be configured with a number of PRACH slots within a 60 kHz slot. For example, the WTRU may be indicated with the number of PRACH slots within a reference 60kHz slot. In an example, the WTRU may be configured with the number of PRACH slots for high SCS values such as 120kHz, 480kHz, 960kHz, etc., where the WTRU may consider the 60kHz PRACH slot as the reference slot.

[0128] In embodiments, the WTRU may be configured with a number of time-domain PRACH occasions within a PRACH slot (N^A,slot). For example, the WTRU may be configured with the number of consecutive ROs that are located within a PRACH slot in time domain.

[0129] In embodiments, the WTRU may be configured with a PRACH duration. For example, the WTRU may be configured with the duration of an RO in number of symbols.

[0130] In embodiments, a WTRU may receive the frequency domain resource allocations for the ROs based on one or more of the following higher-layer parameters: msg1 -Frequencystart or msgA-RO- FrequencyStart, if configured, indicates the offset of the lowest PRACH transmission occasion in frequency domain with respect to the PRB 0; or msg1-FDM or msgA-RO-FDM, if configured, indicates the number of PRACH transmission occasions that are FDMed in one time-domain RO. In the latter case, the WTRU may receive, identify, or be configured with the number of ROs in frequency domain (M per each time-domain PRACH occasion based on the higher layer parameter msg1-FDM, msg1-FDM-16, or msgA-RO-FDM, if configured, where msg1-FDM={one, two, four, eight}; and / or the WTRU may number the PRACH frequency resources nRA={0,1,...,M-1}, starting from the lowest frequency, in increasing order in the initial uplink BWP during the initial access or the active uplink BWP otherwise.

[0131] In embodiments, a WTRU may receive the association and mapping between the SS / PBCH block indexes and PRACH transmission occasions based on higher layer parameter ssb-perRACH-OccasionAndCB- PreamblesPerSSB = {1 / 8,1 / 4, 1 / 2, 1,2,4,8, 16}. The parameter indicates the number of SS / PBCH block indexes associated with a PRACH transmission occasion in addition to the number of preambles per SS / PBCH block index per PRACH occasion.

[0132] SSB to RO mapping is described below.

[0133] In embodiments, in a random access procedure, a WTRU may be provided with a number of SSB indexes associated with one RACH occasion by ssb-perRACH-OccasionAndCB-PreamblesPerSSB, within an SSB-RO mapping cycle, s shown for example in the configuration 500 in FIG. 5. In an example, as shown in FIG. 6, each SSB index (610, 612 ... 614) is mapped to N=4 configured consecutive ROs, ssb-perRACH- OccasionAndCB-PreamblesPerSSB = 1 / 4, Total number of SSBs = 6, and Msg1-FDM = 4. In such embodiments, the WTRU may select one RO randomly out of the N configured ROs to transmit a PRACH preamble.

[0134] SSB to RO mapping in SBFD systems is described below.

[0135] In embodiments, a WTRU may receive a configuration or indication of transmitted SSB indexes (e.g., which indicates which SSBs are actually being transmitted), for example via ssb-PositionsInBurst (e.g., via SIB1 or RRC).

[0136] In embodiments, a WTRU may select an SSB (e.g., during initial access or BFR).

[0137] In embodiments, a WTRU may receive configuration information including a first RACH configuration (e.g., for legacy ROs) and a second (e.g., supplementary) RACH configuration (e.g., for SBFD ROs).

[0138] In embodiments, a WTRU may receive an indication (e.g., SBFD-SSB-subset) that indicates a subset of the transmitted SSBs (e.g., SSB indexes) that can be used for random access (RA) in an SBFD time resource (e.g., slot) . For example, the indicated SBFD-SSB-subset may be in the form of a bitmap. The value 0 may indicate that the corresponding SSB cannot be used for RA in an SBFD time resource, the value 1 may indicate that corresponding SSB can be used for RA in an SBFD time resource.

[0139] In embodiments, a WTRU may determine valid non-SBFD ROs and a corresponding SSB-to-RO mapping for the transmitted SSBs. The WTRU may determines a first set of valid ROs (e.g., non-SBFD ROs) based on the first RACH configuration and maps the SSB indexes of the transmitted SSBs (e.g., provided by ssb-PositionslnBurst) to the valid non-SBFD ROs in increasing order of SSB index.

[0140] In embodiments, based on the received SSB subset indication, the WTRU may determine valid SBFD ROs and a corresponding SSB-to-RO mapping for the indicated SBFD SSB subset that can be used in an SBFD time resource. The WTRU may determine a second set of ROs (e.g., supplementary or SBFD ROs) based on the second RACH configuration and maps the SSB indexes in the SBFD SSB subset to the validsupplementary or SBFD ROs, for example in ascending order of RO index, and for example based on a (pre)configured order, formulation, equation, etc., as described in more detail below.

[0141] Selecting a valid RO for SSB to RO mapping in SBFD systems is described below.

[0142] In embodiments, based on one or both of the determined SSB-to-RO mappings, when the selected SSB is in the SBFD SSB subset, the WTRU may select a valid RO corresponding to the selected SSB from an (e.g., the earliest) SBFD time resource that includes one or more valid SBFD ROs corresponding to the selected SSB when, for example, one or more of the following applies: (a) the WTRU is configured to indicate its SBFD capability using an SBFD RO; (b) the SBFD time resource is earlier than the next (e.g., earliest) non-SBFD time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB; (c) the earliest valid RO(s) corresponding to the SSB are in a non-SBFD time resource and the SBFD time resource is within a threshold number of time resources after the non-SBFD time resource (e.g., this may reduce collisions in the non-SBFD ROs); and / or (d) timing (e.g., next, earlier, earliest) may be with respect to when the WTRU determines to perform a PRACH preamble transmission.

[0143] In embodiments, based on one or both of the determined SSB-to-RO mappings, when the selected SSB is in the SBFD SSB subset, the WTRU may select a valid RO corresponding to the selected SSB from a non-SBFD time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB when the non-SBFD time resource is the earliest time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB.

[0144] The WTRU may then transmit a PRACH preamble using the selected RO.

[0145] In embodiments, a WTRU may monitor, receive, detect, and / or select an SSB in an SSB burst. In an example, the WTRU may select the SSB during initial access procedure or as part of beam failure detection (BFR) procedure. For example, the WTRU may measure the received power (e.g., RSRP) based on the received SSBs and select an SSB based on the measured received power (e.g., with highest RSRP). The WTRU may use the selected SSB for connecting to a cell and / orfor PRACH preamble transmission to the cell. The WTRU may receive a physical broadcast channel (PBCH). The PBCH may carry system information. The PBCH may include or carry a master information block (MIB). The term MIB may be used to represent the content, information, payload, and / or bits carried by the PBCH. PBCH and MIB may be used interchangeably herein. The PBCH may be part of an SS / PBCH block (SSB). The SSB may have an SSB index. A gNB or cell may transmit one or more SSBs where each SSB may have an SSB index.

[0146] In embodiments, a WTRU may use one or more configuration information items received as part of PBCH, MIB, and / or SSB to determine the resources to monitor, receive and / or detect Control Resource Set Zero (CORESETO) for receiving TypeO-PDCCH Common Search Space (CSS). The TypeO-PDCCH CSS may include indications to one or more System Information Blocks (SIB), for example SIB1.

[0147] In embodiments, a WTRU may receive, be configured, and / or indicated with one or more parameters indicating the transmitted SSBs in an SSB burst. For example, the WTRU may receive an indication, forexample ssb-Positions / nBurst, that may include bitmap (e.g., via SIB1 and / or RRC) to indicate the transmitted SSBs within the SSB burst.

[0148] RACH Occasion configurations for SSB to RO mapping in SBFD systems are described below.

[0149] In embodiments, a WTRU may be configured with one or more RACH occasion (RO) types. For example, the WTRU may be configured with a Type 1 RO, where the Type 1 ROs coincide with one or more TDD UL-only time instances. In another example, the WTRU may be configured with a Type 2 RO, where the Type 2 ROs coincide with one or more SBFD and / or supplementary time instances. The WTRU may be configured with PRACH transmission based on one or more of the configured RO types. In an example, the random access resources corresponding to different RO types may be mutually exclusive.

[0150] In embodiments, a WTRU may receive a first set of configuration information on random-access procedure for the Type 1 ROs and a second set of configuration information on random-access procedure for the Type 2 ROs. The first and second set of configuration information may include information on time and frequency resources where the ROs may be scheduled. For example, the WTRU may receive the configuration information via SIB, RRC, MAC-CE, DCI, etc. In an example, the WTRU may receive the indications as part of SIB during initial access. In another example, the WTRU may receive the indications via RRC for BFR procedure. In another example, the WTRU may receive the indications via MAC-CE as part of PDCCH order.

[0151] In embodiments, the first and second sets of PRACH configurations may include indications on the number of ROs that may be mapped in frequency domain per each configured RO time instance, for the first type ROs and the second type ROs, respectively. That is, the WTRU may receive configurations on the number of ROs that are FDM-ed in one RO time instance (e.g., via msg1-FDM). In an example, the WTRU may be configured with (M1) consecutive ROs that may be FDM-ed in frequency domain per configured RO time instance in the first type ROs. In another example, the WTRU may be configured with (M2) consecutive ROs that may be FDM-ed in frequency domain per configured RO time instance in the second type ROs.

[0152] In embodiments, the WTRU may receive a single set of RACH configurations in time domain, to be used for both Type 1 and Type 2 ROs. That is, if the WTRU is not enabled or in incapable of using the supplementary Type 2 ROs (e.g., SBFD ROs), the WTRU may only consider Type 1 ROs as valid (e.g., legacy UL-only ROs), and the WTRU may consider the Type 2 ROs as invalid. Otherwise, in case a WTRU (e.g., SBFD-capable and / or SBFD-aware WTRU) is capable or is enabled of using supplementary Type 2 ROs, the WTRU may consider both Type 1 and Type 2 ROs as valid ROs. Alternatively, the WTRU may be indicated and / or configured to only consider the Type 2 ROs as valid ROs.

[0153] SSB subsets configured for SBFD operation for SSB to RO mapping in SBFD systems are described below.

[0154] In embodiments, a WTRU may receive, be configured and / or indicated with one or more indications and / or configuration information, where the indication may indicate a subset of the transmitted SSBs that can be used for random access (RA) procedure in Type 2 ROs (e.g., SBFD and / or supplementary ROs). Forexample, the WTRU may receive the subset of SSB indexes that can be used for SSB-to-RO mapping in Type 2 ROs. In an example, the SSB subset indication may indicate one or more SSBs out of all configured SSB indexes, for example indicated via ssb-Positions / nBurst. In an example, the WTRU may receive the SSB subset indication via SIB, RRC, MAC-CE, DCI, etc.

[0155] In embodiments, the SSB subset indication may be in the form of a bitmap, where each bit may be associated with one of the SSB indexes from the configured set of transmitted SSB indexes (e.g., configured via ssb-Positions / nBurst). In an example, a first value (e.g., zero) may indicate that the corresponding SSB index cannot be used for RA in a Type 2 RO (e.g., SBFD and / or supplementary RO). In another example, a second value (e.g., one) may indicate that corresponding SSB index can be used for RA in a Type 2 RO. If the WTRU is not provided with SSB subset indication, the WTRU may determine SSB indexes from the configured set of transmitted SSB indexes (e.g., configured via ssb-Positions / nBurst).

[0156] Exemplary SSB-to-RO mapping procedures are described below.

[0157] In embodiments a WTRU may use the first set of RACH configurations for determining SSB-to-RO mapping for the configured and / or indicated transmitted SSBs (e.g., via ssb-Positions / nBurst) in Type 1 ROs. That is, the WTRU may determine a first set of valid Type 1 ROs (e.g., non-SBFD ROs) based on the first RACH configuration and may map the SSB indexes of the transmitted SSBs (e.g., provided by ssb- PositionsInBurst) to the valid Type 1 ROs in increasing order of SSB indexes.

[0158] In embodiments, a WTRU may determine the valid Type 2 supplementary ROs based on the received SSB subset indication and may determine the SSB-to-RO mapping accordingly. In embodiments, the WTRU may determine a second set of valid Type 2 ROs (e.g., SBFD and / or supplementary ROs) based on the second RACH configuration. In embodiments, the WTRU may use the SSB subset indication for determining the valid Type 2 ROs and for mapping SSB-to-RO in Type 2 supplementary ROs. The WTRU may perform SSB-to-RO mapping in Type 2 supplementary ROs in increasing order of RO indexes, where the WTRU may determine the order of SSB indexes in the mapping based on one or more configurations, indications, mapping tables, mapping offsets, mapping indexes, equations, formula, etc.

[0159] Selecting ROs from among valid ROs for SSB to RO mapping in SBFD systems is described below.

[0160] In embodiments, a WTRU may select an RO for PRACH preamble transmission from the valid Type 1 or Type 2 ROs, based on one or more conditions. For example, after the WTRU determines the valid ROs and SSB-to-RO mapping for the determined valid ROs in Type 1 and Type 2 ROs, the WTRU may select one of the valid ROs from Type 1 or Type 2 ROs based on one or more of the following conditions. In an example, in the following conditions, the timing (e.g., next, earlier, earliest) may be with respect to when the WTRU determines to perform a PRACH preamble transmission.

[0161] In embodiments, a WTRU may select a valid RO corresponding to the selected SSB from a Type 2 RO (e.g., the earliest) wherein, for example, one or more of the following may apply:

[0162] (a) In embodiments, the selection of a valid RO may be based on indication of mode of operation:For example, a WTRU may be configured to indicate whether the WTRU may operate based on a first mode of operation or a second mode of operation based on the RO resources that the WTRU may use. For example, the WTRU may use the Type 2 RO to indicate operation based on a first mode of operation (e.g., to a gNB). In an example, the WTRU may indicate that the WTRU may be capable to operate based on SBFD operation by using Type 2 RO. In another example, the WTRU may indicate that WTRU’s preferred mode of operation may be to operate based on SBFD operation by using Type 2 RO.

[0163] (b) In embodiments, the selection of a valid RO may be based on earliest in time: For example, the WTRU may use the Type 2 RO, associated with the selected SSB, if the corresponding Type 2 RO’s time resource is earlier than the next (e.g., earliest) Type 1 RO, that is associated with the selected SSB. For example, the WTRU may use the SBFD RO in case the SBFD RO time resource is earlier or closer in time than the next (earliest) non-SBFD time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB.

[0164] In embodiments, the selection of a valid RO may be within a configured time range: For example, the valid Type 1 ROs, associated with the selected SSB, may be earlier than the valid Type 2 ROs, associated with the selected SSB. In an example, the WTRU may be configured to use the corresponding Type 2 RO, if the Type 2 RO is within a time range and / or within a threshold number of time resources after the corresponding Type 1 RO, in time domain. That is, although the Type 2 RO that is associated with the selected SSB is not the earliest available RO, but since it is within a configured time range after the earliest available Type 1 RO, the WTRU may be configured to use the Type 2 RO. This may be, for example, to reduce the collision in Type 1 ROs.

[0165] In embodiments, WTRU may select a valid RO corresponding to the selected SSB from a valid Type 1 RO (e.g., non-SBFD), corresponding to the selected SSB, if the Type 1 RO’s time resource is the earliest time resource that may include one or more valid Type 1 ROs corresponding to the selected SSB.

[0166] In the above embodiments, the WTRU may transmit a PRACH preamble based on the selected RO.

[0167] PUSCH occasion mapping in small data transmission (SDT) is described below.

[0168] In embodiments, a WTRU may receive, be provided, indicated, and / or configured with one or more configurations on one or more configured UL grants on UL BWP and / or UL subbands in one or more supplementary time instances. In embodiments, the WTRU may receive the configurations via SIB, RRC, MAC- CE, DCI, etc. In an example, the supplementary time instances may include SBFD symbols, slots, frames, etc. For example, the configured UL BWP may be on the initial UP BWP. For example, the configured UL subbands may be on the initial BWP. In an example, one or more configured UL grant configurations may be indicated via ConfiguredGrantConfig. In another example, one or more configured UL grant configurations may be for configured grant Type 1 PUSCH transmissions. For example, the configured grant Type 1 PUSCH transmissions may be used for Small Data Transmission (SDT).

[0169] In embodiments, a WTRU may receive, be configured, and / or indicated with a subset of SSB indexes to be used for determining and mapping PUSCH occasions (PO). For example, the WTRU may determine the indicated subset of SSB indexes for mapping a number of valid PUSCH occasions for PUSCH transmissions over an association period, for example for configured grant Type 1 PUSCH transmissions, for example on the initial UL BWP (e.g., for Small Data Transmission (SDT)). In an example, the WTRU may be indicated with the subset of SSB indexes out of configured SSB indexes (e.g., via ssb-Positions / nBurst). In an example, a PUSCH occasion for a PUSCH transmission may be indicated by one or more time and frequency resources, where the indicated PUSCH occasions may be associated with a DM-RS (e.g., indicated via cg- DMRS-Configuration) for the configuration of PUSCH transmissions.

[0170] In embodiments, the SSB subset indication for PO mapping may be in the form of a bitmap, where each bit may be associated with one of the SSB indexes from the configured set of transmitted SSB indexes (e.g., configured via ssb-Positions / nBurst). In an example, a first value (e.g., zero) may indicate that the corresponding SSB index cannot be used for PO mapping in a supplementary RO (e.g., Type 2 RO and / or SBFD RO). In another example, a second value (e.g., one) may indicate that corresponding SSB index can be used for PO mapping in a supplementary RO. If the WTRU is not provided with SSB subset indication for PO mapping, the WTRU may determine SSB indexes from the configured set of transmitted SSB indexes (e.g., configured via ssb-PositionsInBurst).

[0171] In embodiments, a WTRU may map the indicated subset of SSB indexes for PO mapping to valid POs and associated DMRS resources. In embodiments, a WTRU may use the following order options: For example, first, in increasing order of DMRS resource indexes within a PUSCH occasion, where a DMRS resource index DMRSidis determined first in an ascending order of a DMRS port index and second in an ascending order of a DMRS sequence index. For example, second, in increasing order of PUSCH configuration period indexes.

[0172] In embodiments, the WTRU may select an SSB, where the SSB may be selected as best SSB, for example with highest measured RSRP. The WTRU may transmit one or more configured PUSCH transmissions based on the selected SSB. The WTRU may use the determined mapping between the indicated subset of SSB indexes for PO mapping and valid POs for transmission of the configured PUSCH.

[0173] SSB to RO mapping types are described below.

[0174] In embodiments a WTRU may receive the list of SSB indexes via ssb-Positions / nBurst (e.g., via SIB1 , RRC, etc.).

[0175] In embodiments a WTRU may select an SSB (during initial access or BFR), based on which the WTRU performs random access.

[0176] In embodiments a WTRU may receive configurations on RO slots, where the configured RO symbols may be a first RO type (non-SBFD ROs) or a second RO type (SBFD ROs).

[0177] In embodiments a WTRU may receive an indication on SBFD-SSB-subset.

[0178] In embodiments a WTRU may receive a first and a second set of SSB-to-RO mapping configurations (via SI B 1 , RRC, etc.), where each set at least includes Msg1-FDM, N, etc. The WTRU may use the first set of SSB-RO mapping for the first RO type (e.g., legacy, non-SBFD) and the second set of SSB-RO mapping for the second RO type (e.g., SBFD).

[0179] In embodiments, in the case of legacy ROs ,a WTRU may determine the SSB-to-RO mappings in the first type of ROs based on the first set of SSB-to-RO mapping configurations, in the order of preamble index, freq., time, and RO slot.

[0180] In embodiments, in case at least a second type of RO (e.g., supplementary / SBFD RO) precedes the first type of RO in a TDD cycle, WTRU uses the second set of SSB-RO mapping configurations in the second type RO.

[0181] Mapping procedure for SSB to RO mapping is described below.

[0182] In a case of SBFD ROs, in embodiments, a WTRU may map the SSB indexes provided by SBFD- SSB-subset to valid SBFD ROs, as follows. A WTRU is indicated, as part of the received configurations, on whether the SSB-RO mapping is separate or joint between the first type and second type ROs. In a case of separate mapping, in embodiments, a WTRU may initiate the SBFD ROs from the Frame 0, in the order of preamble index, freq., time, and SBFD RO slot. This is shown for example in FIG. 7. FIG. 7, 700 shows DL slot 710 SBFD slots 712 (RO1 , RO2, RO3, RO4), 714 (RO5, RO6, RO7, RO8) and 716 (RO9, ROW, RO 11, ROW) and UL slot 718 (RO1-RO8). In a case of joint mapping, in embodiments, a WTRU may initiate the SBFD ROs from the Frame 0 based on a (pre)configured order, equation, function, etc. based on the maximum number of SSBs (e.g., received via SBFD-SSB-subset).

[0183] In an example of joint mapping, in embodiments, a WTRU may map the SSB indexes provided by SBFD-SSB-subset to valid supplementary / SBFD ROs, starting with the highest SSB index and incrementing (as shown, for example in FIG. 4 and described herein above), in the following order: First, in increasing order of preamble indexes within a single PRACH occasion. Second, in increasing order of frequency resource indexes for frequency multiplexed PRACH occasions. Third, in increasing order of time resource indexes for time multiplexed PRACH occasions within a PRACH slot. Fourth, in increasing order of indexes for SBFD / supplementary RO slot. Fifth, in increasing order of indexes for TDD cycles. FIGS. 8, 9, W and 11 , which are described in detail below, show additional embodiments for joint SSB-RO mapping in SBFD and non-SBFD ROs.

[0184] In embodiments, a WTRU may continue mapping in SBFD / supplementary ROs in the n-th TDD cycle until all configured SSB indexes are mapped to the configured ROs (either in SBFD or non-SBFD ROs) within the preceding n TDD cycles within an SSB-RO mapping cycle.

[0185] In embodiments, a WTRU may use the determined SSB-to-RO mapping for PRACH transmission based on a selected or configured SSB index.

[0186] In embodiments, a WTRU may monitor, receive, detect, and / or select an SSB, for example in an SSB burst. In an example, the WTRU may select the SSB during initial access procedure or as part of beam failure detection (BFR) procedure. For example, the WTRU may measure the received power (e.g., RSRP) based on the received SSBs and select an SSB based on the measured received power (e.g., with highest RSRP). The WTRU may use the selected SSB for connecting to a cell and / or for PRACH preamble transmission to the cell. Alternatively, the WTRU may receive indications on the SSB indexes to be used for PRACH preamble transmission. For example, the WTRU may receive indications via PDCCH-order, for example, via MAC-CE.

[0187] In embodiments, a WTRU may receive, be configured, and / or indicated with one or more parameters indicating the transmitted SSBs in an SSB burst. In embodiments, the WTRU may receive an indication, for example ssb-Positions / nBurst, that may include bitmap (e.g., via SIB1 and / or RRC) to indicate the transmitted SSBs within the SSB burst.

[0188] In embodiments a WTRU may be configured with one or more RACH occasion (RO) types. For example, the In embodiments may be configured with a Type 1 RO, where the Type 1 ROs coincide with one or more TDD UL-only time instances. In embodiments a WTRU may be configured with a Type 2 RO, where the Type 2 ROs may coincide with one or more SBFD and / or supplementary time instances. The WTRU may be configured with PRACH transmission based on one or more of the configured RO types. In embodiments, the Type 2 ROs may be configured separately or be determined (e.g., created, derived, identified) from the Type 1 ROs, e.g., as the same as Type 1 ROs, e.g., without or with adjustment of one or more parameters for the Type 1 ROs.

[0189] In embodiments, a WTRU may receive a first set of configuration information on random-access configurations for the Type 1 ROs and a second set of configuration information on random-access procedure for the Type 2 ROs. The first and second set of configuration information may include information on time and frequency resources where the ROs may be scheduled. For example, the WTRU may receive the configuration information via SIB, RRC, MAC-CE, DCI, etc.

[0190] In embodiments, the first and second sets of PRACH configurations may include indications on the number of ROs that may be mapped in frequency domain per each configured RO time instance, for the first type ROs and the second type ROs, respectively. That is, the WTRU may receive configurations on the number of ROs that are FDM-ed in one RO time instance (e.g., via msg1-FDM). In an example, the WTRU may be configured with (M1) consecutive ROs that may be FDM-ed in frequency domain per configured RO time instance in the first type ROs. In embodiments, the WTRU may be configured with (M2) consecutive ROs that may be FDM-ed in frequency domain per configured RO time instance in the second type ROs.

[0191] In embodiments, a WTRU may receive, be configured and / or indicated with one or more indications and / or configuration information, where the indication may indicate a subset of the transmitted SSBs that can be used for random access (RA) procedure in Type 2 ROs (e.g., SBFD and / or supplementary ROs). Inembodiments, a WTRU may receive the subset of SSB indexes that can be used for SSB-to-RO mapping in Type 2 ROs. In an example, the SSB subset indication may indicate one or more SSBs out of all configured SSB indexes, for example indicated via ssb-Positions / nBurst. In embodiments a WTRU may receive the SSB subset indication via SIB, RRC, MAC-CE, DCI, etc.

[0192] In embodiments, a WTRU may receive, be indicated, and / or configured with a first and a second set of RACH configurations for determining SSB-to-RO mapping for the configured and / or indicated transmitted SSBs (e.g., via ssb-Positions / nBurst) in Type 1 and Type 2 ROs, respectively. In embodiments, a WTRU may determine a first set of valid Type 1 ROs (e.g., non-SBFD ROs) based on the first RACH configuration and may map the SSB indexes of the transmitted SSBs (e.g., provided by ssb-PositionsInBurst) to the valid Type 1 ROs in increasing order of SSB indexes. In an example, the WTRU may perform the mapping in Type 1 ROs, in the order of preamble index, ROs mapped in frequency, RO time resources, and RO slots.

[0193] In embodiments, in case at least a Type 2 RO (e.g., supplementary / SBFD RO) precedes or is configured in addition to a Type 1 RO in a TDD cycle, the WTRU may use the second set of SSB-RO mapping configurations in the corresponding Type 2 RO. For example, the WTRU may determine a second set of valid Type 2 ROs (e.g., SBFD and / or supplementary ROs) based on the second RACH configurations and may map the indicated subset of SSB indexes to the determined valid Type 2 ROs.

[0194] Mapping procedure in supplementary and / or Type 2 ROs is described below.

[0195] In embodiments, a WTRU may determine valid SBFD ROs and a corresponding SSB-to-RO mapping for a set of SSB indexes that can be used in an SBFD time resource, where the set of SSB indexes may be determined based on the second RACH configuration and / or the received SSB subset indication.

[0196] In embodiments, for the corresponding SSB-to-RO mapping, a WTRU may receive a configuration or indication to apply a separate SSB-RO mapping in SBFD and non-SBFD ROs, as illustrated in FIG. 5. Based on a TDD UL / DL configuration where the WTRU determines a time-domain pattern among DL Slot(s), SBFD Slot(s), and / or UL Slot(s), the WTRU may (firstly) determine the corresponding SSB-to-RO mapping starting from a UL Slot, e.g., SSB1 (RO1), SSB1(RO2), SSB2(RO3), ..., SSB4(RO8), illustrated in the UL slot of the figure. Based on the separate SSB-RO mapping, the WTRU may (secondly) determine the corresponding SSB- to-RO mapping separately (e.g., independently, in parallel) starting from a first SBFD Slot, e.g., SSB1 (RO1), SSB1(RO2), SSB2(RO3), SSB2(RO4) in the first SBFD slot, followed by SSB3(RO5), SSB3(RO6), SSB4(RO7), ..., illustrated in the SBFD Slots of the figure. This separate SSB-RO mapping in SBFD and non- SBFD ROs may continue separately in the next TDD-UL / DL pattern period (e.g., cycle).

[0197] Joint mapping embodiments for backward SSB-to-RO mapping in supplementary and / or Type 2 ROs are described below.

[0198] In embodiments, for the corresponding SSB-to-RO mapping, a WTRU may receive a configuration or indication to apply a joint mapping in SBFD and non-SBFD ROs and / or a backward (e.g., descending orderbased) SSB-RO mapping in SBFD ROs, as illustrated, for example, in FIG. 4. Based on a TDD UL / DLconfiguration where the WTRU determines a time-domain pattern among DL Slot(s), SBFD Slot(s), and / or UL Slot(s), the WTRU may (first) determine the corresponding SSB-to-RO mapping starting from a UL Slot, e.g., SSB1 (RO1), SSB1(RO2), SSB2(RO3), SSB4(RO8), illustrated in the UL slot of the figure. Based on the backward SSB-RO mapping (e.g., being enabled or configured), the WTRU may (second) determine the corresponding SSB-to-RO mapping for SBFD ROs, starting from a first SBFD Slot by applying a backward mapping order from the last possible SSB-index (e.g., based on the received SSBPositionsInBurst, SSB subset indication, etc.), e.g., SSB16(RO31), SSB16(RO32), SSB15(RO29), SSB15(RO30) in the first SBFD slot, followed by SSB14(RO27), SSB14(RO28), SSB13(RO25), ..., illustrated in the SBFD Slots of the figure. This backward SSB-RO mapping in SBFD ROs may continue in the available (e.g., valid) SBFD ROs of the next TDD-UL / DL pattern period (e.g., cycle). This may provide benefits in terms of avoiding possible duplication of an RO being associated with a same SSB index across SBFD and non-SBFD symbols (e.g., within a given TDD-UL / DL pattern period), e.g., compared with the separate SSB-RO mapping where the first two SBFD Slots have duplication of the UL Slot 718 shown in FIG. 7, where if the WTRU selects, e.g., SSB15 for PRACH transmission the available ROs associated with the SSB15 does not exist in the example of separate SSB-RO mapping but exist in the example of the backward SSB-RO mapping, based on avoiding duplicated allocation, contrary to the separate SSB-RO mapping case where ROs associated with SSB1 , SSB2, SSB3, or SSB4 are shown in both SBFD and non-SBFD symbols, unnecessary, in the example of separate SSB-RO mapping case (FIG. 7).

[0199] In embodiments, the backward SSB-RO mapping case does not limit the example operation as in FIG. 4, meaning the actual mapping rule may be defined or configured differently, e.g., within a same TDD- UL / DL pattern period, without loss of generality based on the embodiments described throughout the disclosure. For example, FIG. 10 may show a different embodiment based on the proposed backward (e.g., descending order-based) SSB-RO mapping, where the difference from FIG. 4 may be the starting SBFD Slot to apply the backward SSB-RO mapping is not the first SBFD Slot but a S-th SBFD Slot (e.g., in the TDD- UL / DL pattern period). In FIG. 10, an example case of S = 3 is illustrated, where the WTRU may determine the corresponding SSB-to-RO mapping for SBFD ROs, starting from the third SBFD Slot 1016 by applying a backward mapping order from the last possible SSB-index (e.g., based on the received SSB subset indication), e.g., SSB15(RO29), SSB15(RO30), SSB16(RO31), SSB16(RO32) in the third SBFD slot, followed by SSB13(RO25), SSB13(RO26), SSB14(RO27), SSB14(RO28) in the second SBFD slot 1014, followed by SSB11(RO23), SSB11(RO24), SSB12(RO25), SSB12(RO26) in the first SBFD slot 1012, illustrated in the SBFD slots of the diagram 1000. For completeness, FIG. 10 also shows DL slot 1010 and UL slot 1018. The embodiments disclosed herein support other possible variations of example operations to avoid the said possible duplication of an RO being associated with a same SSB index across SBFD and non-SBFD symbols (e.g., within a given TDD-UL / DL pattern period), without loss of generality.

[0200] In embodiments, a WTRU may select an RO for PRACH preamble transmission from the valid Type 1 or Type 2 ROs, based on one or more conditions shown in at least one embodiment of the disclosure, and the WTRU may transmit a PRACH preamble based on the selected RO.

[0201] Joint mapping embodiments with continuous SSB-to-RO mapping in SBFD and non-SBFD ROs are described below.

[0202] In and embodiment of joint mapping in SBFD and non-SBFD ROs, for the corresponding SSB-to- RO mapping, a WTRU may receive a configuration or indication to apply a continuous SSB-RO mapping in SBFD and non-SBFD ROs, as illustrated in the diagram 800 in FIG. 8. Based on a TDD UL / DL configuration where the WTRU determines a time-domain pattern among DL Slot(s) 810, SBFD Slot(s) 812, 814, 816, and / or UL Slot(s) 818, the WTRU may (first) determine the corresponding SSB-to-RO mapping starting from a UL Slot 818, e.g., SSB1 (RO1), SSB1(RO2), SSB2(RO3), ..., SSB4(RO8). Based on the continuous SSB-RO mapping (e.g., being enabled or configured), the WTRU may (second) determine the corresponding SSB-to-RO mapping for SBFD ROs, starting from a first SBFD slot 812 by applying a continuous mapping order from the lastly mapped SSB and RO pair in the UL Slot within the same TDD-UL / DL pattern period (e.g., (also) based on the received SSB subset indication), e.g., SSB5(RO9), SSB5(RO10), SSB6(RO11), SSB6(RO12) in the first SBFD slot, followed by SSB7(RO13), SSB7(RO14), SSB8(RO15), ..., illustrated in SBFD slots 814 of the figure. This continuous SSB-RO mapping may continue in the available (e.g., valid) SBFD and / or non-SBFD ROs of the next TDD-UL / DL pattern period (e.g., cycle).

[0203] In embodiments of the joint mapping in SBFD and non-SBFD ROs, for the corresponding SSB-to- RO mapping, the WTRU may receive a configuration or indication to apply a continuous SSB-RO mapping in ascending order of slot indexes in SBFD and non-SBFD ROs, as illustrated in FIG. 9. Based on a TDD UL / DL configuration where the WTRU determines a time-domain pattern among DL slot(s) (e.g. 910), SBFD slot(s) (e.g. 912, 914, 916), and / or UL Slot(s) (e.g. 918), the WTRU may (first) determine the corresponding SSB-to- RO mapping starting from a first SBFD slot 912, e.g., SSB1(RO1), SSB1 (RO2), SSB2(RO3), ..., SSB6(RO12), illustrated in the three SBFD slots 912, 914, 916 of the figure. Based on the continuous SSB-RO mapping in ascending order of slot indexes (e.g., being enabled or configured), the WTRU may (second) determine the corresponding SSB-to-RO mapping for non-SBFD ROs, starting from a first UL Slot e.g. 918 by applying a continuous mapping order from the lastly mapped SSB and RO pair in the SBFD slot within the same TDD- UL / DL pattern period (e.g., (also) based on the received SSB subset indication), e.g., SSB7(RO13), SSB7(R014), SSB8(R015), SSB8(R016) in the UL slot of the figure. This continuous SSB-RO mapping may continue in the available (e.g., valid) SBFD and / or non-SBFD ROs of the next TDD-UL / DL pattern period (e.g., cycle).

[0204] In embodiments, a WTRU may select an RO for PRACH preamble transmission from the valid Type 1 or Type 2 ROs, based on one or more conditions shown in at least one embodiment of the disclosure, and the WTRU may transmit a PRACH preamble based on the selected RO.

[0205] Joint mapping embodiments with explicit SSB-lndex-offset-based SSB-to-RO mapping in supplementary and / or Type 2 ROs are described below.

[0206] In embodiments, for the corresponding SSB-to-RO mapping, a WTRU may receive a configuration or indication to apply a joint mapping in SBFD and non-SBFD ROs and / or an explicit SSB-lndex-offset-based SSB-to-RO mapping in SBFD ROs, as illustrated in the diagram 1100 in FIG. 11. Based on a TDD UL / DL configuration where the WTRU determines a time-domain pattern among DL slot(s), SBFD slot(s), and / or UL slot(s), the WTRU may (first) determine the corresponding SSB-to-RO mapping starting from a UL Slot 1118, e.g., SSB1 (RO1), SSB1(RO2), SSB2(RO3), ..., SSB4(RO8). Based on the (explicit) SSB-lndex-offset-based SSB-to-RO mapping (e.g., being enabled or configured), the WTRU may (second) determine the corresponding SSB-to-RO mapping for SBFD ROs, starting from a first SBFD slot by applying an explicit SSB-lndex-offset (which may be configured or indicated) from the last possible SSB-index (e.g., based on the received SSB subset indication), e.g., SS B9(R017), SSB9(R018), SSB 10(R019), SSB 10(RO20) in the first SBFD slot 1112, followed by SSB11(RO21), SSB11(RO22), SSB12(RO23), SSB12(RO24), illustrated in SBFD slot 1114 and SSB 13(RO25), SSB 13(RO26), SSB 14(RO27), SSB 14(RO28) illustrated in SBFD slot 1116, where the WTRU may determine the starting SSB index of 9 from the last possible SSB-index of 4 in the UL slot plus the configured or indicated SSB-lndex-offset (e.g., which may be 5 in this example). This explicit SSB-lndex-offset- based SSB-to-RO mapping in SBFD ROs may continue in the available (e.g., valid) SBFD ROs of the next TDD-UL / DL pattern period (e.g., cycle). These embodiments may This may provide benefits avoiding possible duplication of an RO being associated with a same SSB index across SBFD and non-SBFD symbols (e.g., within a given TDD-UL / DL pattern period), e.g., compared with the separate SSB-RO mapping where the first two SBFD Slots have duplication of the UL Slot shown in FIG. 7, where if the WTRU selects, e.g., SSB13 for PRACH transmission the available ROs associated with the SSB13 does not exist in the example of separate SSB-RO mapping but exist (in the third SBFD slot) in the example of the explicit SSB-lndex-offset-based SSB- to-RO mapping, based on avoiding duplicated allocation, contrary to the separate SSB-RO mapping case where ROs associated with SSB1, SSB2, SSB3, or SSB4 are shown in both SBFD and non-SBFD symbols, unnecessary, in the example of separate SSB-RO mapping case (FIG. 7). The embodiments disclosed herein support other possible variation of example operations to avoid the said possible duplication of an RO being associated with a same SSB index across SBFD and non-SBFD symbols (e.g., within a given TDD-UL / DL pattern period), without loss of generality.

[0207] In embodiments, a WTRU may select an RO for PRACH preamble transmission from the valid Type 1 or Type 2 ROs, based on one or more conditions shown in at least one embodiment of the disclosure, and the WTRU may transmit a PRACH preamble based on the selected RO.

[0208] Embodiments for SSB to RO mapping types in SBFD systems are described below.

[0209] In embodiments a SBFD-capable WTRU receives an indication on the subset of configured SSBs that can be used for SBFD operation, where the WTRU considers the indicated subset of SSBs for SSB-to-RO mapping, as shown for example in FIG. 12.

[0210] In embodiments, the subset may be used to enable beam nulling or UL muting for CLI mitigation. For the SSBs in the allowed subset, the network can increase the opportunities for PRACH transmission which can reduce latency and collisions for PRACH transmission. These extra ROs can also be used for PRACH repetition to support coverage enhancement with reduced latency. Herein, the terms PRACH occasion, random access occasion, and RO may be used interchangeably.

[0211] In embodiments (shown, e.g. 1212)the WTRU receives a configuration or indication of transmitted SSB indexes (e.g., which indicates which SSBs are actually being transmitted), for example via ssb- PositionsInBurst (e.g., via SIB1 or RRC).

[0212] In embodiments, at 1210, the WTRU selects an SSB (e.g., during initial access or BFR)

[0213] In embodiments (shown, e.g. 1211) the WTRU receives configuration information including a first RACH configuration (e.g., for legacy ROs) and a second (e.g., supplementary) RACH configuration (e.g., for SBFD ROs).

[0214] In embodiments, at 1214, the WTRU receives an indication (e.g., SBFD-SSB-subset) that indicates a subset of the transmitted SSBs (e.g., SSB indexes) that can be used for random access (RA) in an SBFD time resource (e.g., slot). E.g., The indicated SBFD-SSB-subset may be in the form of a bitmap. The value 0 may indicate that the corresponding SSB cannot be used for RA in an SBFD time resource, the value 1 may indicate that corresponding SSB can be used for RA in an SBFD time resource.

[0215] In embodiments, at 1216, the WTRU determines valid non-SBFD ROs and a corresponding SSB- to-RO mapping for the transmitted SSBs. WTRU determines a first set of valid ROs (e.g., non-SBFD ROs) based on the first RACH configuration and maps the SSB indexes of the transmitted SSBs (e.g., provided by ssb-Positions / nBurst) to the valid non-SBFD ROs in increasing order of SSB index.

[0216] In embodiments, at 1218, based on the received SSB subset indication, the WTRU determines valid SBFD ROs and a corresponding SSB-to-RO mapping for the indicated SBFD SSB subset that can be used in an SBFD time resource. WTRU determines a second set of ROs (e.g., supplementary or SBFD ROs) based on the second RACH configuration and maps the SSB indexes in the SBFD SSB subset to the valid supplementary or SBFD ROs, for example, as shown at 1220, in ascending order of RO index, and for example in descending order of SSB indexes from the highest SSB index in the SBFD SSB subset (e.g., see FIG. 4).

[0217] In embodiments, at 1222, based on one or both of the determined SSB-to-RO mappings, when the selected SSB is in the SBFD SSB subset, the WTRU selects a valid RO corresponding to the selected SSB according to at least one of the following (shown at 1224): (a) a WTRU selects a valid RO corresponding to the selected SSB from a non-SBFD time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB when the non-SBFD time resource is the earliest time resource that includes one or morevalid non-SBFD ROs corresponding to the selected SSB; (b) a WTRU selects a valid RO corresponding to the selected SSB from an (e.g., the earliest) SBFD time resource that includes one or more valid SBFD ROs corresponding to the selected SSB when, for example, one or more of the following applies: (1)The WTRU is configured to indicate its SBFD capability using an SBFD RO. (2) The SBFD time resource is earlier than the next (e.g., earliest) non-SBFD time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB. (3) The earliest valid RO(s) corresponding to the SSB are in a non-SBFD time resource and the SBFD time resource is within a threshold number of time resources after the non-SBFD time resource (e.g., this may reduce collisions in the non-SBFD ROs. (4) Timing (e.g., next, earlier, earliest) may be with respect to when the WTRU determines to perform a PRACH preamble transmission

[0218] In embodiments, at 1226, the WTRU, then transmits a PRACH preamble using the selected RO.

[0219] A method performed by a first wireless transmit / receive unit (WTRU) may comprise: receiving a configuration of synchronization signal block (SSB) indexes that can be used for sub-band non-overlapping full duplex (SBFD) operation; selecting an SSB based on the received configuration of SSB indexes; receiving configuration information including a first random access channel (RACH) configuration; determining a first set of valid RACH opportunities (RO’s) and a corresponding SSB to RO mapping based on the first RACH configuration that can be used in an SBFD time resource; selecting a RO from among the first set of valid ROs, and transmitting a physical random access channel (PRACH) preamble using the selected RO. In further embodiments the method may include the configuration information further comprising a second RACH configuration and further comprising determining a second set of valid ROs and corresponding SSB to RO mapping based on the second RACH configuration. In further embodiments the method may include the WTRU indicating an SFBD capability using an SFBD RO. In further embodiments the method may include the SBFD time resource being earlier than a next non-SBFD time resource that includes one or more valid non-SBFD ROs corresponding to the selected SSB. In further embodiments the method may include an earliest valid RO corresponding to the selected SSB is in a non-SBFD time resource and the SBFD time resource is within a threshold number of time resources after the non-SBFD time resource. In further embodiments the method may include selection of the RO being based on when the WTRU determines to transmit the PRACH preamble. In further embodiments the method may include selecting the SSB during and initial access procedure or as part of a beam failure detection (BFR) procedure. In further embodiments the method may include selecting the SSB based on a measured received power. In further embodiments the method may include connecting to a cell using the selected SSB. In further embodiments the first set of RACH configurations may include the number of ROs that can be mapped in a frequency domain.

[0220] In further embodiments a WTRU is configured to perform any of the above-stated methods.

[0221] Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program,software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magnetooptical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, WTRU, terminal, base station, RNC, or any host computer.

Claims

CLAIMSWhat is Claimed:

1. A method performed by a first wireless transmit / receive unit (WTRU), the method comprising: receiving configuration information including a set of synchronization signal block (SSB) indexes, wherein the set of SSB indexes includes a first subset of SSB indexes and a second subset of SSB indexes; receiving an indication that the second subset of SSB indexes are valid for sub-band non-overlapping full duplex (SBFD) random access channel (RACH) opportunities (ROs); mapping the second subset of SSB indexes to SBFD ROs in ascending order of RO indexes and in descending order of SSB indexes; selecting either an RO associated with the first subset of SSB indexes or an RO associated with the second subset of SSP indexes; and transmitting a physical random access channel (PRACH) preamble using the selected RO.

2. The method of claim 1, wherein the WTRU is configured to indicate SBFD capability using an SBFD RO.

3. The method of claim 1 or 2, wherein the selection of RO is based on the selected RO being an earliest RO in time.

4. The method of claim 1 or 2, wherein the selection of RO is based on the RO being within a predetermined number of time resources after a non-SBFD RO in time.

5. The method of any of claims 1-4, wherein the selection of the RO is based on when the WTRU determines to transmit the PRACH preamble.

6. The method of any of claims 1-5, wherein the WTRU selects the SSB during and initial access procedure or as part of a beam failure recovery (BFR) procedure.

7. The method of any of claims 1-6, wherein the WTRU selects the SSB based on a measured received power.

8. The method of any of claims 1-7, wherein the WTRU connects to a cell using the selected SSB.

9. The method of any of claims 1-8, wherein the configuration information includes RACH configurations that include a number of ROs that can be mapped in a frequency domain.

10. The method of any of claims 1-9, wherein the configuration information further comprises a second RACH configuration and further comprising determining a second set of valid ROs and corresponding SSB to RO mapping based on the second RACH configuration.

11. A wireless transmit / receive unit (WTRU) comprising: a transceiver; and a processor; wherein the transceiver and processor are configured to: receive configuration information including a set of synchronization signal block (SSB) indexes, wherein the set of SSB indexes includes a first subset of SSB indexes and a second subset of SSB indexes; receive an indication that the second subset of SSB indexes are valid for sub-band non-overlapping full duplex (SBFD) random access channel (RACH) opportunities (ROs); map the second subset of SSB indexes to SBFD ROs in ascending order of RO indexes and in descending order of SSB indexes; select either an RO associated with the first subset of SSB indexes or an RO associated with the second subset of SSP indexes; and transmit a physical random access channel (PRACH) preamble using the selected RO.

12. The WTRU of claim 11 , wherein the transceiver and processor are further configured to indicate SBFD capability using an SBFD RO.

13. The WTRU of claim 11 or 12, wherein the selection of RO is based on the selected RO being an earliest RO in time.

14. The WTRU of claim 11 or 12, wherein the selection of RO is based on the RO being within a predetermined number of time resources after a non-SBFD RO in time.

15. The WTRU of any of claims 11-14, wherein the selection of the RO is based on when the processor determines to transmit the PRACH preamble.

16. The WTRU of any of claims 11-15, wherein the transceiver and processor are further configured to select the SSB during an initial access procedure or as part of a beam failure recovery (BFR) procedure.

17. The WTRU of any of claims 11-16, wherein the transceiver and processor are further configured to select the SSB based on a measured received power.

18. The WTRU of any of claims 11-17 wherein the transceiver and processor are further configured to connect to a cell using the selected SSB.

19. The WTRU of any of claims 11-18, wherein the configuration information includes RACH configurations that include a number of ROs that can be mapped in a frequency domain.

20. The WTRU of any of claim 11 , wherein an earliest valid RO corresponding to the selected SSB is in a non-SBFD time resource and the SBFD time resource is within a threshold number of time resources after the non-SBFD time resource.

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