Method for replication of PDU in multi-carrier side link

Abstract

A system, wireless device, and method for PDU replication in a multicarrier sidelink are disclosed. The method may include the wireless device determining replication behavior based on the CBR, sensing results and / or resource selection results, HARQ feedback, SL channel measurements reported by a peer-to-peer WTRU, an RX WTRU explicit indication / request, and QoS of data to be transmitted. The method may also include the wireless device determining how long to maintain replication activation. The method may also include the wireless device configured to have an inhibition mechanism for enabling replication. The method may also include the replication behavior depending on a broadcast type associated with the SLRB.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 395,223, filed on August 4, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] Vehicle communication is a mode of communication whereby WTRUs communicate directly with each other. For V2X operation, there are two scenarios. In the in-coverage scenario, the WTRU receives assistance from the network to start sending and receiving V2X messages. In the out-of-coverage scenario, the WTRU uses pre-configured parameters to start sending and receiving V2X messages.

[0004] V2X communications are supported in LTE and are inspired by previous work on device-to-device (D2D) communications. V2X communication services may cover four different types of communication services: V2V (vehicle-to-vehicle), where vehicle WTRUs communicate directly with each other; V2I (vehicle-to-infrastructure), where vehicle WTRUs communicate with RSU / eNB; V2N (vehicle-to-network), where vehicle WTRUs communicate with the core network; and V2P (vehicle-to-pedestrian), where vehicle WTRUs communicate with WTRUs based on special conditions (e.g., low battery capacity). Summary of the invention

[0005] A system, wireless device and method for PDU duplication in a multi-carrier side link are disclosed. The wireless device is configured to perform the method. The wireless device includes a receiver, a transmitter operatively coupled to the receiver, and a processor operatively coupled to the receiver and the transmitter. Alternatively, the wireless device includes a transceiver and a processor operatively coupled to the transceiver.

[0006] The method may include the wireless device determining the replication behavior based on the QoS of the data to be sent. The method may also include the wireless device determining the replication behavior based on the CBR that may be measured on one or more SL carriers. The method may also include the wireless device determining the replication behavior based on sensing results and / or resource selection results. The method may also include the wireless device determining the replication behavior based on HARQ feedback. The method may also include the wireless device determining the replication behavior based on SL channel measurement results reported by a peer WTRU. The method may also include the wireless device determining the replication behavior based on an explicit indication / request of the RX WTRU. The method may also include the wireless device determining how long to keep the replication activated. The method may also include the wireless device configured to have a prohibition mechanism for enabling replication. The method may also include the replication behavior depending on the broadcast type associated with the SLRB.

[0007] The wireless device may be a wireless transmit receive unit (WTRU), a base station, an evolved Node B, a gNB, a transmit / receive point (TRP), a vehicle, a vehicle WTRU, a network node, an access point (AP), a station (STA), and a relay node.

[0008] A system and method are disclosed. The system and method may be performed in a wireless transmit and receive unit (WTRU) to provide replication on multiple sidelink (SL) carriers. The system and method include: receiving a configuration of a sidelink radio bearer (SLRB); enabling packet data convergence protocol (PDCP) replication for the SLRB based on a sensing result of a condition from the configuration; replicating all protocol data units (PDUs) from the SLRB on two SL carriers of the multiple SL carriers for a configured time period after the enabling; and monitoring a replication disable condition of the SLRB.

[0009] The sensing result may include a determination that the SLRB condition is met. The configuration of the SLRB may include a threshold time difference between the selected resource and a packet delay budget (PDB). The threshold time difference may be for each SLRB. The configuration of the SLRB may include a time period for replicating the PDU. The time period may be for each SLRB. The condition of the SLRB may be the arrival of data. The condition of the SLRB may include a time difference between the selected resource and the PDB of available data being less than the threshold time difference. The replication condition of the SLRB may include preemption. The replication condition of the SLRB may include the remaining PDBs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate like elements, and in which:

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

[0012] Figure 1B is an example of an example that can be Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within the illustrated communication system;

[0013] Figure 1C is an example of an example that can be Figure 1A a system diagram of an example Radio Access Network (RAN) and an example Core Network (CN) used within the illustrated communication system;

[0014] Figure 1D is an example of an example that can be Figure 1AA system diagram of another example RAN and another example CN used within the illustrated communication system;

[0015] Figure 2 Methods of copying and duplicating behavior generally as described herein are illustrated;

[0016] Figure 3 A method performed in a wireless transmit and receive unit (WTRU) to provide replication on multiple sidelink (SL) carriers is illustrated; and

[0017] Figure 4 An example of a PDU duplication method in a multi-carrier side link is illustrated. DETAILED DESCRIPTION

[0018] A system, wireless device and method for PDU duplication in a multi-carrier side link are disclosed. The wireless device is configured to perform the method. The wireless device includes a receiver, a transmitter operatively coupled to the receiver, and a processor operatively coupled to the receiver and the transmitter. Alternatively, the wireless device includes a transceiver and a processor operatively coupled to the transceiver.

[0019] The method may include the wireless device determining the replication behavior based on the QoS of the data to be sent. The method may also include the wireless device determining the replication behavior based on the CBR that may be measured on one or more SL carriers. The method may also include the wireless device determining the replication behavior based on sensing results and / or resource selection results. The method may also include the wireless device determining the replication behavior based on HARQ feedback. The method may also include the wireless device determining the replication behavior based on SL channel measurement results reported by a peer WTRU. The method may also include the wireless device determining the replication behavior based on an explicit indication / request of the RX WTRU. The method may also include the wireless device determining how long to keep the replication activated. The method may also include the wireless device configured to have a prohibition mechanism for enabling replication. The method may also include the replication behavior depending on the broadcast type associated with the SLRB.

[0020] The wireless device may be a wireless transmit receive unit (WTRU), a base station, an evolved Node B, a gNB, a transmit / receive point (TRP), a vehicle, a vehicle WTRU, a network node, an access point (AP), a station (STA), and a relay node.

[0021] A system and method are disclosed. The system and method may be performed in a wireless transmit and receive unit (WTRU) to provide replication on multiple sidelink (SL) carriers. The system and method include: receiving a configuration of a sidelink radio bearer (SLRB); enabling packet data convergence protocol (PDCP) replication for the SLRB based on a sensing result of a condition from the configuration; replicating all protocol data units (PDUs) from the SLRB on two SL carriers of the multiple SL carriers for a configured time period after the enabling; and monitoring a replication disable condition of the SLRB.

[0022] The sensing result may include a determination that the SLRB condition is met. The configuration of the SLRB may include a threshold time difference between the selected resource and a packet delay budget (PDB). The threshold time difference may be for each SLRB. The configuration of the SLRB may include a time period for replicating the PDU. The time period may be for each SLRB. The condition of the SLRB may be the arrival of data. The condition of the SLRB may include a time difference between the selected resource and the PDB of available data being less than the threshold time difference. The replication condition of the SLRB may include preemption. The replication condition of the SLRB may include the remaining PDBs.

[0023] Figure 1A 1 is a diagram illustrating an example communication system 100 in which one or more disclosed examples may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, and filter bank multi-carrier (FBMC), etc.

[0024] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110 and other networks 112, but it should be understood that the disclosed examples 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 send and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), consumer electronic devices, and devices operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0025] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an evolved Node B (eNB), a Home Node B, a Home evolved Node B, a Next Generation Node B (such as a gNode B (gNB)), a New Radio (NR) Node B, a site controller, an access point (AP), a wireless router, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0026] 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), and a relay node. The base station 114a and / or the base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of a licensed spectrum and an unlicensed spectrum. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Therefore, in one example, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an example, 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 send and / or receive signals in a desired spatial direction.

[0027] 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).

[0028] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA, among others. 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), that may use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols, such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​Uplink (UL) Packet Access (HSUPA).

[0029] In an example, 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).

[0030] In an example, 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.

[0031] In an example, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may together implement LTE radio access and NR radio access, for example using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0032] In other examples, 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, CDMA20001X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), GSM Enhanced Data Rates for Evolution (EDGE), GSM EDGE (GERAN), etc.

[0033] Figure 1AThe base station 114b in the example may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in local areas such as commercial venues, homes, vehicles, campuses, industrial facilities, sky corridors (e.g., for use by drones), and roads. In one example, 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 example, 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 example, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or a femtocell. As Figure 1A As shown, 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.

[0034] 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 different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the specification, the CN 106 may be configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. Figure 1A Although not shown in the figure, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize NR radio technology, the CN 106 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0035] The CN 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0036] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0037] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with the example.

[0038] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal decoding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0039] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from a base station via an air interface 116. For example, in one example, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an example, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, an IR, UV, or visible light signal. In another example, the send / receive element 122 may be configured to send and / or receive both an RF signal and an optical signal. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0040] Although the transmit / receive element 122 Figure 1B Although depicted as a single element in the figure, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one example, 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.

[0041] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0042] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other examples, 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).

[0043] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0044] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that, while remaining consistent with the example, the WTRU 102 may acquire location information by way of any suitable location-determination method.

[0045] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, Modules, frequency modulation (FM) radio units, digital music players, media players, video game player modules, Internet browsers, virtual reality and / or augmented reality (VR / AR) devices and activity trackers, etc. The peripheral device 138 may include one or more sensors. The sensor may be one or more of the following: a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geographic location sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and a humidity sensor, etc.

[0046] 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 specific subframes for both 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 for reducing and / or substantially eliminating self-interference via hardware (e.g., a choke) or via signal processing performed by a processor (e.g., a separate processor (not shown) or via the processor 118). In an example, 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 specific subframes for both UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via hardware (e.g., a choke) or via signal processing performed by a processor (e.g., a separate processor (not shown) or via the processor 118). In an example, 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 specific subframes for both UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be concurrent and / or simultaneous.

[0047] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 according to an example. 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.

[0048] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with the example. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one example, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0049] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, and scheduling of users in the UL and / or DL, among other things. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0050] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although the foregoing elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0051] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, and selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c. 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.

[0052] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during an inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0053] 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.

[0054] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0055] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative examples such terminals may (eg, temporarily or permanently) use a wired communication interface with a communication network.

[0056] In a representative example, the other network 112 may be a WLAN.

[0057] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a 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 to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and destined for the STA may arrive through the AP and may be delivered to the STA. Traffic originating from the STA and destined for a target outside the BSS may be transmitted to the AP to be delivered to the corresponding target. Traffic between STAs within the BSS may be transmitted through the AP, for example, where the source STA may transmit traffic to the AP, and the AP may deliver traffic to the target STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source STA and the target STA (e.g., directly between them) using direct link establishment (DLS). In certain representative examples, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0058] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a dynamically set width. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative examples, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may 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.

[0059] High throughput (HT) STAs may communicate using a 40 MHz wide channel (eg, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels) to form a 40 MHz wide channel.

[0060] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and the data can be sent by sending STA. At the receiver of the receiving STA, the above-mentioned operation for 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0061] 802.11af and 802.11ah support operating modes below 1 GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative example, 802.11ah may support meter type control / machine type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0062] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (which only supports a 1MHz operating mode) is transmitting to the AP, all available bands may be considered busy even if most of the available bands remain idle.

[0063] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0064] Figure 1D 1 is a system diagram illustrating the RAN 104 and the CN 106 according to an example. As noted above, the RAN 104 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0065] 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 the example. 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 example, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In the example, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In an example, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and the gNB 180b (and / or the gNB 180c).

[0066] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or Transmission Time Intervals (TTIs) of varying or scalable lengths (e.g., containing different numbers of OFDM symbols and / or varying absolute time lengths over time).

[0067] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchors. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeB 160a, 160b, 160c may act as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0068] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, interworking between DC, NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b and routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0069] Figure 1D The illustrated CN 106 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although the aforementioned elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0070] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of non-access stratum (NAS) signaling, and mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, and services for MTC access. 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.

[0071] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 106 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 106 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy implementation and QoS, and providing DL data notifications. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0072] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N3 interface, 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, and providing mobility anchoring, etc.

[0073] 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 acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one example, the WTRUs 102a, 102b, 102c may be connected to the local DN 185a, 185b via the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and the N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0074] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more simulation devices (not shown): WTRU102a to 102d, base station 114a to 114b, evolved Node B 160a to 160c, MME 162, SGW 164, PGW 166, gNB180a to 180c, AMF 182a to 182b, UPF 184a to 184b, SMF 183a to 183b, DN 185a to 185b and / or any other device described herein. The simulation device may be one or more devices configured to mimic one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0075] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. A simulation device may be directly coupled to another device for the purpose of testing and / or performing tests using over-the-air wireless communications.

[0076] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuits (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0077] V2X resource allocation is provided in LTE. LTE defines two modes of operation in V2X communications. One mode, in which the network provides the WTRU with scheduling assignments for V2X sidelink transmissions, is generally referred to as Mode 3. The other mode, in which the WTRU autonomously selects resources from a configured / preconfigured resource pool, is generally referred to as Mode 4. V2X LTE defines two types of resource pools, including a receive pool that is monitored for receiving V2X transmissions, and a V2X transmit pool that is used by the WTRU to select transmit resources in Mode 4. A WTRU configured in Mode 3 may generally not use a transmit pool.

[0078] These resource pools are semi-statically signaled to the WTRU via RRC signaling. In Mode 4, the WTRU may use sensing before selecting resources from the RRC configured transmit pool. LTE V2X generally does not support dynamic resource pool reconfiguration, as the pool configuration may only be carried via SIB and / or dedicated RRC signaling.

[0079] New Radio (NR) V2X resource allocation is provided. NR inherits two resource allocation modes from LTE. One resource allocation mode is gNB scheduled resource allocation, commonly referred to as Mode 1 resource allocation. The other resource allocation mode is WTRU autonomous resource allocation, commonly referred to as Mode 2 resource allocation. The concepts of resource pools and sensing for Mode 2 resource allocation are also inherited from LTE.

[0080] LTE includes multi-carrier sidelink (SL) transmission. V2X sidelink communication supports carrier aggregation (CA) in the sidelink. CA is applicable to both in-coverage WTRUs and out-of-coverage WTRUs. For CA in the sidelink, neither primary nor secondary component carriers are defined. Each resource pool (pre-)configured for V2X sidelink communication transmission or reception is associated with a single carrier. When a WTRU supporting CA in the sidelink uses autonomous resource selection, the WTRU performs carrier selection and may select one or more carriers for V2X sidelink communication transmission. Carrier selection is performed at the MAC layer based on the CBR of the (pre-)configured carriers for the V2X sidelink communication and the PPPP of the V2X message to be sent. When resource reselection is triggered, carrier reselection may be performed and resource reselection may be triggered for each sidelink process. In order to avoid frequent switching across different carriers, the WTRU may continue to use the carrier already selected for transmission if the measured CBR on that carrier is below a (pre-)configured threshold. The selected carriers may have the same synchronization reference or the same synchronization priority configuration. For a WTRU using autonomous resource selection, logical channel prioritization is performed for the sidelink resources on the carrier based on the CBR measured on the carrier and the PPPP of the sidelink logical channel.

[0081] There are duplications in the NR Uu. To support uplink periodic traffic for services with time-to-live requirements, configured grant resources may be used so that both the gNB and the WTRU are aware of the mapping between the services and the configured grants. This allows the gNB to trigger the time-to-live state entry for the corresponding DRB using the configured grant retransmission schedule (addressed by the CS-RNTI). Once in the time-to-live state, the WTRU activates the RLC entity configured for the DRB for replication to prevent subsequent messages from failing to meet the time-to-live requirement. If CA or DC replication for a DRB has been activated, the DRB may enter the time-to-live state when any retransmission grant is received for any of its active LCHs.

[0082] In LTE, replication is enabled based on PPPR – if the PPPR of a packet is above a threshold, the WTRU will perform replication on two different carriers. For NR, to support more stringent reliability requirements, replication on multiple carriers may be supported. Replication may be controlled more dynamically and turned on when needed to avoid significantly increasing sidelink resource usage.

[0083] Figure 2A method 200 of duplication and duplication behavior as generally described herein is illustrated. The method 200 includes determining 210 whether the WTRU can perform duplication. The determination 210 may include whether the duplication is associated with an SLRB, and when other conditions such as those described herein are met. The method 200 includes determining 220 the number of RLC branches associated with the SLRB (maximum, minimum). The method 200 includes determining 230 the number of PDCP copies sent by the WTRU for each PDCP PDU (maximum, minimum). The determination 230 may include copies on the SL carrier and possibly on different SL carriers. The method 200 includes identifying / monitoring 240 parameters or conditions for enabling / disabling duplication. The identification / monitoring may include any parameters or conditions associated with determining whether / when to enable / disable duplication of a PDCP PDU (e.g., a CBR threshold for enabling / disabling duplication, a HARQ NACK threshold for enabling / disabling duplication, etc.). For example, a first condition may be used to configure the SLRB to have multiple RLC branches (allowing duplication), and duplication may be turned on or off later based on a second condition. The method 200 includes determining 250 specific carriers to which duplication may be applied. For example, specific carriers to which duplication may be applied or specific carriers to which duplication is to be applied. For example, duplicate RLC channels may be configured over different carriers, and the WTRU may use one or more of the carriers to duplicate the PDCP based on certain conditions and actual criteria, conditions, parameters used in the conditions, etc., for determining whether to perform duplication, the number of duplications, etc.

[0084] Figure 3 A method 300 performed in a wireless transmit and receive unit (WTRU) to provide replication on multiple sidelink (SL) carriers is illustrated. The method 300 includes receiving 310 a configuration of a sidelink (SL) radio bearer (SLRB). The method 300 includes determining to enable 320 packet data convergence protocol (PDCP) replication for the SLRB based on sensing results. The sensing results may be based on conditions provided in the configuration. The WTRU may determine the replication behavior based on one or more factors. These factors may be used independently or in combination to propose conditions for enabling / disabling replication based on conditions including a combination of factors described herein.

[0085] The WTRU may determine the duplication behavior based on the QoS of the data to be sent. In one example, the WTRU may determine the duplication behavior based on the QoS of the data to be sent. Specifically, the WTRU may be configured with a mapping of SL bearers to duplication parameters or duplication behavior. Alternatively, the WTRU may be configured with a mapping of QoS flows or PQI parameters to duplication behavior.

[0086] In one example, the WTRU may be configured with a CBR threshold for determining whether to perform duplication. The CBR threshold may be (pre)configured per SLRB. For example, if the CBR is above / below a threshold specific to the SLRB, the WTRU may perform duplication of the PDU associated with the SLRB.

[0087] In another example, for a given SLRB, the WTRU may be configured to have multiple RLC entities. Specifically, the WTRU may determine the number of RLC entities based on the SLRB configuration. The WTRU may create a bearer. The WTRU may determine whether to copy to each RLC entity and the number of entities based on other conditions herein.

[0088] The WTRU may determine the duplication behavior based on the CBR. This may be measured on one or more SL carriers. In one example, the WTRU determines the duplication behavior based on the measured CBR on one or more SL carriers. The WTRU may determine the duplication behavior based on the following numerous factors applied alone or in combination.

[0089] The CBR of the bearer with the highest / lowest CBR among the selected carriers. For example, if the carrier with the largest measured CBR among the selected carriers has a CBR below a threshold, the WTRU may perform duplication. For example, if the carrier with the smallest measured CBR among the selected carriers has a CBR below a threshold, the WTRU may perform duplication.

[0090] Average CBR measured on the selected carrier. For example, if the average CBR measurement in the selected carrier is below a threshold, the WTRU may perform replication.

[0091] The range or difference in CBR between carriers, including the carriers on which duplication may be performed, has the highest CBR and the lowest CBR. For example, if the CBR difference between the selected carrier with the highest CBR and the carrier with the lowest CBR is above / below a threshold, the WTRU may perform duplication on the selected carrier.

[0092] The CBR threshold may be used to determine whether duplication may be performed, and may also be configured based on other criteria, such as: a CBR threshold for each priority level of data being considered for duplication; a CBR threshold for a given number of carriers on which duplication is configured for a bearer, or on which duplication is determined by the WTRU; a CBR threshold for each SLRB for which packet duplication is being considered; and a CBR threshold for a given number of carriers on which the WTRU has selected for transmission or is allowed to perform transmission.

[0093] The WTRU may determine the duplication behavior based on the sensing results and / or the resource selection results. In one example, the mode 2 WTRU determines the duplication behavior based on the sensing results or any conditions associated with the sensing. Such conditions may include whether the WTRU detects the need to preempt a resource. For example, when the WTRU triggers preemption of one of its selected resources and the indicated resources, it may enable duplication. The resource may be configured as a bearer for enabling such duplication behavior. For example, when the WTRU triggers a re-evaluation of the selected resource, the WTRU may enable duplication even if the resource has not been indicated. These conditions may include whether the WTRU selects the resource after increasing the RSRP threshold used to determine resource availability by 3dB. For example, if, in a given resource selection situation, the WTRU increases the RSRP threshold by 3dB N times (where N may be 1, or greater than 1) to reach a percentage of available resources for successful resource selection, the WTRU may enable duplication. These conditions may be based on conditions associated with the number of available resources on one or more carriers during resource selection. For example, the WTRU may be configured to have a threshold percentage of available resources (or an offset relative to the percentage configured for successful resource selection for a given priority). If the percentage of available resources is below a threshold, the WTRU may enable replication. These conditions may be based on conditions associated with the time difference between the PDB / remaining PDBs and the selected resources or the time difference of the remaining PDBs themselves. For example, if the remaining PDBs are below a threshold at the time of resource selection, the WTRU may enable replication. For example, if the time between the PDB used for resource selection and the actual selected resource is less than a threshold, the WTRU may enable replication. These conditions may be based on conditions associated with the relationship between resources selected in different carriers. For example, the WTRU may have resources selected in different carriers. The WTRU may determine whether to enable replication based on the relationship between these resources (e.g., frequency difference, time difference, etc.). For example, if the WTRU has resources in different carriers that are at least / at most separated by a threshold time, the WTRU may enable replication. These conditions may be based on the quality of the selected resources. For example, the WTRU may determine whether to enable replication based on the measured RSRP of any SCI indicating the resources to be occupied. Specifically, if the resources are reserved by another WTRU and the RSRP of the SCI that reserves such resources is above a threshold, the WTRU may enable replication.

[0094] In any of the described examples, resource selection criteria for enabling duplication may be triggered on a single carrier. Specifically, if one or more of the above conditions are met in any carrier where the WTRU may perform transmissions, such as for a particular SLRB, the WTRU may initiate duplication. Alternatively, if the condition is met on several or all carriers, duplication may be enabled. Specifically, there may be multiple carriers (or configured, or determined based on the criteria described herein) that enable duplication when any of the conditions are met for each of the carriers.

[0095] In any of the examples described, the WTRU may enable replication on one or more SLRBs that allow replication. For example, the WTRU may enable replication on all SLRBs that allow replication. For example, the specific SLRBs on which replication is enabled may be determined based on the specific condition itself. For example, the bearer may be configured with a specific threshold for PDBs for resource differences, and when the selected resource meets the threshold, replication may be enabled for the bearer. Alternatively, another condition may be used to determine which SLRBs have replication enabled after the first condition is met. For example, after determining that replication is enabled on one or more SLRBs as a result of the resource selection condition, the WTRU may determine which SLRBs to enable replication on based on the measured CBR and a comparison with the configured CBR threshold.

[0096] The WTRU may determine the replication behavior based on HARQ feedback. In one example, the WTRU may determine the replication based on the receipt / non-reception of HARQ feedback. Specifically, the WTRU may use the rules defined by the reception of ACK / NACK / DTX to determine whether to enable (and / or possibly disable) replication on one or more SLRBs. The rule may be defined based on the number of consecutive ACK / NACK / DTX received. For example, if the number of consecutive NACKs or DTXs exceeds a threshold, the WTRU may enable replication. Once replication is enabled, the specific SLRB for which replication is enabled may further depend on the number of consecutive NACK / DTXs. Specifically, a threshold number of consecutive NACK / DTXs for enabling SLRB replication may be configured for each priority level or each SLRB. For example, when the number of consecutive ACKs received on the SL is higher than a threshold, the WTRU may disable replication (on a specific SLRB, or on all SLRBs for which replication has been enabled). The rule may be defined based on the number of ACK / NACK / DTXs received within a configured time period. The rule may be defined based on the number of ACK / NACK / DTXs received from different WTRUs in a multicast HARQ scenario. For example, if the ratio of ACK to NACK is below a threshold, the WTRU may enable replication. For example, if the number of WTRUs transmitting NACKs for a particular TB is greater than a threshold, the WTRU may enable replication. For example, if at least X WTRUs transmit ACKs for a particular TB and replication is enabled, the WTRU may disable replication. A combination of the above rules may be used to determine replication behavior.

[0097] The WTRU may determine the replication behavior based on the SL channel measurement results reported by the peer WTRU. In one example, the WTRU may determine the conditions for enabling replication based on the SL channel measurement results reported by the peer WTRU, such as CQI, RSRP, CR, CBR (or similar channel occupancy metrics associated with a single WTRU). For example, if the reported SL measurement value for one or a group of carriers (e.g., CQI, RSRP) from the peer WTRU is below a threshold, the WTRU may enable replication. As discussed herein for CBR, similar considerations for multiple carriers (e.g., average CQI / RSRP) may be considered. For example, the WTRU may be configured to have a first condition for enabling replication and a second condition for disabling replication. Such conditions may depend on the reported SL measurement values ​​and other factors herein (e.g., amount of time). For example, the WTRU may be configured to have a first condition for enabling replication (e.g., CQI is below a first threshold) and a second condition for disabling replication (e.g., CQI is above a second threshold for a period of time). For example, the WTRU may be configured with measurement-based conditions to determine the number of carriers to be replicated. Specifically, if the SL channel measurement results reported by the peer WTRU are within a first range, the WTRU may replicate on two carriers, if the SL channel measurement results reported by the peer WTRU are within a second range, replicate on three carriers, and so on. For example, the WTRU may receive a channel occupancy measurement (e.g., CR) from a peer WTRU. Such channel occupancy metrics may be defined on multiple carriers / resource pools to represent the amount of time that the WTRU is busy sending and therefore unable to receive. Alternatively, multiple metrics (e.g., one metric per carrier) may be transmitted to indicate the occupancy metric of each carrier. If the occupancy metric of one or more carriers (or the combined metric across multiple carriers) is above a threshold, the TX WTRU may determine to perform replication. The TX WTRU may decide the number of carriers or specific carriers to use for replication based on the occupancy metric. Specifically, the TX WTRU may replicate on the carrier with the lowest occupancy. Specifically, the TX WTRU may replicate on multiple carriers determined by those carriers whose occupancy metrics are below a threshold. Specifically, at least one replicated carrier may be selected from the carriers whose occupancy metrics are below a threshold. Similar conditions can be used to disable replication after it has been enabled, including after a period of time when the condition is met.

[0098] Without loss of generality, the same examples may be applied using measurements performed by a TX WTRU as well as measurements reported by a peer WTRU.

[0099] The WTRU may determine the replication behavior based on an explicit indication / request from the RX WTRU. In one example, the TX WTRU determines the replication behavior based on an explicit / implicit indication from a peer WTRU. Specifically, the peer WTRU may use similar criteria discussed herein to determine whether the replication behavior of the TX WTRU and the replication behavior of the peer WTRU may be transmitted to the TX WTRU using implicit or explicit signaling. In one example, the RX WTRU may determine the need for replication based on a count of ACK / NACKs associated with received packets (i.e., decoding successes versus failures). Based on certain criteria associated with, for example, the ratio of ACKs to NACKs, the RX WTRU may indicate to the TX WTRU that replication is enabled, including for a specific LCH. The TX WTRU may then enable replication, including for the logical channels / bearers indicated by the TX WTRU.

[0100] The method 300 includes duplicating 330 a protocol data unit (PDU) from a SLRB on two SL carriers among a plurality of SL carriers for a configured time period. The WTRU may determine how long to keep the replication activated. The WTRU may enable replication based on one or a combination of the triggers / conditions described herein. After enabling replication, the WTRU may maintain replication for a period of time, or until another trigger occurs. For example, the WTRU may be configured to have a timer (defining a period of time) to maintain replication after a trigger to enable replication. The WTRU may start a timer when enabling replication, and after the timer expires (the period of time expires), the WTRU may disable replication. The WTRU may also determine the value of the timer based on factors associated with QoS. For example, the WTRU may be configured to have a timer specific to each SLRB, and the timer may be set to a value associated with the SLRB, where data may be available when replication is enabled.

[0101] The method 300 includes monitoring 340 a duplication disabling condition of the SLRB. Alternatively or in addition, the WTRU may be configured with a second condition for disabling duplication when duplication is enabled. Such a condition may be related to any of the factors described herein and may or may not be associated with the same factors used to enable duplication. For example, when duplication is enabled, the WTRU may determine to disable duplication based on HARQ feedback received from a peer WTRU. Specifically, after duplication is enabled, if a consecutive number of HARQ ACKs received from a peer WTRU reaches a threshold, the WTRU may disable duplication.

[0102] Alternatively, the WTRU may be configured to maintain replication for multiple PDU transmissions of a SLRB (once turned on based on one or more of the described conditions). For example, once the WTRU turns on replication after a trigger, the WTRU may perform replication on the next N PDUs from each SLRB on all SLRBs that are configured with replication, where N may be configured per SLRB.

[0103] The WTRU may be configured with a prohibition mechanism to enable replication. In one example, the WTRU may be configured with a prohibition mechanism for enabling replication. Specifically, the WTRU may be configured with a condition that does not allow replication to be enabled at a specific time. Such a prohibition mechanism may be configured based on the following. The mechanism may be configured based on the time since the WTRU last performed replication. For example, the WTRU may be allowed to enable replication, including replication associated with a specific SLRB, for no less than a period of time x since the last time replication was enabled, including replication associated with that SLRB. The time period may be specific to the SLRB. The time period may depend on the measured CBR. For example, the WTRU may be configured to have a minimum time to be observed between disabling replication and re-enabling replication, including for the same SLRB, which depends on the priority and CBR. Specifically, for a given priority and CBR, the WTRU may wait at least X seconds between the time replication is disabled and the time the WTRU can enable replication for the SLRB associated with the given priority. The mechanism may be configured based on the CBR or any SL measurement value made since the WTRU last performed replication. For example, if the measured CBR is not higher than the CBR measured the last time replication was enabled, the WTRU may be allowed to enable replication, including associating with the SLRB.

[0104] The replication behavior may depend on the broadcast type associated with the SLRB. In one example, the replication behavior may depend on the broadcast type of the SLRB. For example, the WTRU may be configured to have different maximum numbers of carriers for a given broadcast type, the conditions checked for enabling and / or disabling replication may be different for different broadcast types, the time period for which replication may remain enabled may be configured differently for each broadcast type, etc. In one example, the WTRU determines whether to perform replication of a PDU on multiple sidelink carriers and the number of carriers to replicate based on the QoS of the packet, the average CBR, and the resource (re)selection results. The TX WTRU receives a SL bearer configuration (in the SIB / RRC / pre-configuration) that contains the maximum number of carriers for a given average CBR that allows replication of PDUs containing data from the logical channels of the bearer. The TX WTRU receives data to be sent on a SL bearer that allows replication and performs resource (re)selection. If the time difference between the selected resource and the PDB is less than the threshold, or if the WTRU triggers preemption of the selected resource, the TX WTRU enables duplication of SL bearers on up to the maximum number of configured carriers, and enables HARQ feedback for the duplicated LCH (if configured with disabled HARQ feedback), and continues to perform duplication of SL bearers until the number of consecutive HARQ ACKs for the PDU containing data from the bearer reaches the HARQ ACK threshold.

[0105] Figure 4 An example method 400 for PDU duplication in a multi-carrier sidelink is illustrated. Figure 4 As shown, the TX WTRU may be (pre)configured to have multiple protocol entities (e.g., RLC entities or MAC entities) associated with the SLRB. The protocol entities may each be configured to operate on a carrier that may be used for transmission by the TX WTRU. Specifically, for the multicast case, the TX WTRU may be (pre)configured to have a protocol for each carrier on which a multicast L2 ID may be sent. On the other hand, for the unicast case, the TX WTRU may determine the carrier on which the protocol for replication is created.

[0106] For a given congestion level, the TX WTRU may also be configured with a maximum number of carriers that are allowed to be replicated. Specifically, the SLRB configuration may include a mapping of a CBR range to a maximum number of carriers for replication. The TX WTRU may perform a CBR measurement on each of the carriers configured for replication of the SLRB and may determine an average CBR value over the carrier. Based on the average CBR value and the mapping of the CBR range to the number of carriers, the TX WTRU may determine the maximum number of carriers for PDU replication for the SLRB. The TX WTRU may update the maximum number periodically (e.g., periodically, or when the measured CBR changes).

[0107] Figure 2 The method 200 depicted in 400 includes receiving 410 a configuration of a SLRB. The method 400 includes receiving 420 data and / or a resource (re)selection trigger. At 430, the method 400 includes determining whether a replication condition of the SLRB is satisfied. The condition may include those conditions described herein, including but not limited to preemption and remaining PDBs.

[0108] Resource selection on one or more carriers that the SLRB is configured to use may trigger replication. Upon resource selection, if the resource selection results in periodic (multiple) resources where the selected resource occurs less than a threshold after the remaining PDBs of the data that triggered the resource selection, the WTRU may enable replication. The data considered in such criteria (i.e., the data that triggered the resource selection) may be further associated with the data of the SLRB being considered for replication. The time threshold may be configured per SLRB. In addition, the WTRU may perform such actions for a SLRB as long as the time threshold is configured for that SLRB.

[0109] After resource selection, the WTRU may perform preemption after detecting another transmission by another WTRU on the selected resource. After such detection, the WTRU may also enable duplication (if not already enabled). The WTRU may enable duplication if the preemption occurs on a resource / grant that is being used or can be used to transmit data associated with a SLRB that is configured to allow duplication.

[0110] If the determination 430 is negative, the method 400 may return to receiving 420. If the determination 430 is positive, at 440, the method 400 includes enabling duplication for the SLRB. After enabling 440, the method 400 includes monitoring / checking 450 a duplication disable condition of the SLRB. After enabling duplication, the WTRU may continue to perform duplication until, for broadcast, the time difference between the selected resource and the PDB of the packet is above a threshold multiple times in a row, and for unicast, the number of consecutive HARQ ACKs received from transmissions containing data from the SLRB reaches a threshold.

[0111] When monitoring / checking 450 identifies a disabling condition, method 400 determines whether a replication disabling condition for the SLRB is satisfied at 460. If determination 460 is negative, method 400 continues with monitoring / checking 450. If determination 460 is positive, method 400 disables 470 replication for the SLRB.

[0112] Although features and elements are described above in specific combinations, it will be understood by those of ordinary skill in the art that each feature or element may be used alone or in any combination with 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 (sent via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as built-in hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with software may be used to implement a radio frequency transceiver for a UE, WTRU, terminal, base station, RNC, or any host computer.

Claims

1. A method performed in a wireless transmit and receive unit (WTRU) to provide replication on multiple sidelink (SL) carriers, the method comprising: receiving information indicating configuration of a sidelink radio bearer (SLRB); determining to enable packet data convergence protocol (PDCP) duplication for the SLRB based on a sensing result, wherein the sensing result is based on a condition indicated in the configuration; as well as Each protocol data unit (PDU) is replicated from the SLRB, wherein the replicating is configured to occur on at least two of the plurality of SL carriers within a time period after the determining to enable the replicating.

2. The method of claim 1 , further comprising monitoring a condition for disabling PDCP duplication.

3. The method according to claim 2, wherein the condition for disabling PDCP duplication is a reception signal.

4. The method of claim 2, wherein the condition for disabling PDCP duplication comprises expiration of the time period. 5 . The method according to claim 1 , further comprising receiving information indicating the configuration of the multiple SL carriers. The method of claim 1 , wherein the sensing result comprises a determination that the condition indicated in the configuration is satisfied.

7. The method of claim 1, wherein the configuration of the SLRB comprises a threshold time difference between a selected resource and a packet delay budget (PDB). The method of claim 7 , wherein the condition comprises the threshold time difference.

9. The method of claim 1, wherein the configuration of the SLRB includes the time period for duplicating PDUs.

10. The method of claim 1, wherein the condition indicated in the configuration is reception of data.

11. The method of claim 1, wherein the condition comprises preemption based on information received from another SL WTRU, the other SL WTRU being configured to change a plurality of selected resources of the WTRU.

12. The method of claim 1, wherein the condition is associated with a remaining PDB.

13. A wireless transmit and receive unit (WTRU) configured to provide replication on multiple sidelink (SL) carriers, the WTRU comprising: a transceiver configured to enable the WTRU to communicate; and a processor operatively coupled to the transceiver for: receiving information indicating configuration of a sidelink radio bearer (SLRB); determining to enable packet data convergence protocol (PDCP) duplication for the SLRB based on a sensing result, wherein the sensing result is based on a condition indicated in the configuration; as well as Each protocol data unit (PDU) is replicated from the SLRB, wherein the replicating is configured to occur on at least two of the plurality of SL carriers within a time period after the determining to enable the replicating.

14. The WTRU of claim 13, wherein the processor and the transceiver are operatively coupled to further monitor a condition to disable PDCP duplication.

15. The WTRU of claim 14, wherein the condition to disable PDCP duplication is a received signal.

16. The WTRU of claim 14, wherein the condition for disabling PDCP duplication comprises expiration of the time period.

17. The WTRU of claim 13, wherein the processor and the transceiver are operatively coupled to further receive information indicative of the configuration of the plurality of SL carriers.

18. The WTRU of claim 13, wherein the sensing result comprises a determination that the condition indicated in the configuration is satisfied.

19. The WTRU of claim 13, wherein the configuration of the SLRB comprises a threshold time difference between a selected resource and a packet delay budget (PDB).

20. The WTRU of claim 19, wherein the condition comprises the threshold time difference.

21. The WTRU of claim 13, wherein the configuration of the SLRB includes the time period for duplicating the PDU.

22. The WTRU of claim 13, wherein the condition indicated in the configuration is reception of data.

23. The WTRU of claim 13, wherein the condition comprises preemption based on information received from another SL WTRU, the other SL WTRU being configured to change a plurality of selected resources of the WTRU.

24. The WTRU of claim 13, wherein the condition is associated with a remaining PDB.

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