Logical channel prioritization method supporting sidelink relay

Abstract

A method for UE prioritization and multiplexing of sidelink relay data for simultaneous logical channel prioritization (LCP) procedures in a New Radio (NR) system is proposed. When a UE has services from multiple service classes to send simultaneously, the UE can provide service class-based service prioritization. The sidelink relay service priority is then used for transport interface and resource selection, as well as data multiplexing priority based on the sidelink relay architecture. Specifically, a method is provided on how to perform corresponding logical channel prioritization (LCP) operations for MAC PDU multiplexing. LCP restrictions are taken into account to determine which service classes can be multiplexed together into the same MAC PDU. The multiplexing priority is also used to determine the order and number of services to be included in the MAC PDU.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 972,088, filed on February 10, 2020, entitled “Sidelink Relay Priority,” and U.S. Provisional Application No. 62 / 982,119, filed on February 27, 2020, entitled “Logical Channel Prioritization Method Supporting Sidelink Relay,” under 35 U.S.C. §119, the subject matter of each of which is incorporated herein by reference. Technical Field

[0003] The disclosed embodiments relate generally to wireless network communications, and more particularly to logical channel prioritization (LCP) procedure enhancements to support sidelink transmissions in 5G new radio (NR) wireless communication systems. Background Art

[0004] In various communication scenarios, it is desirable for mobile devices to communicate directly with other devices without relying on network infrastructure as an intermediary. This situation has inspired the design of so-called "sidelink" interfaces directly between mobile devices, for example from one user equipment (UE) to another UE, without going through a base station. In some cases, the use of the sidelink interface may be fully or partially controlled by the base station, for example, the use of the sidelink radio resources may be scheduled by the base station, but the actual communication of data on the sidelink does not go through the base station. The sidelink interface is also called the PC5 interface. Various applications can rely on communication over the sidelink interface, such as vehicle-to-everything (V2X) communication, public safety (PS) communication, and direct file transfer between user devices.

[0005] As an extension of sidelink communication, sidelink relay enables a UE to communicate with the network via another UE, that is, one UE can help another UE forward / relay data to / from the base station (UE-to-Network Relay). Specifically, for remote UEs, the network can be accessed without directly communicating with the base station via the Uu interface. The sidelink relay connection can be configured by a configuration message sent by the base station to the remote UE through the relay UE; the configuration message may include any necessary parameters required for relay operation, as well as other parameters required to establish and maintain the connection. However, in some other cases, when two remote UEs do not have direct visibility of each other on the sidelink interface, the two remote UEs may need to communicate. In these cases, the relay UE can provide relay communication between two remote UEs (UE-to-UE relay).

[0006] There are potential issues in the current LTE and NR V2X designs to support sidelink relay transmissions. It is unclear how the transmitter UE can perform LCP and data multiplexing for traffic from different source entities (network or remote UE) and / or via different interfaces (Uu or PC5 interface) and / or for different applications (sidelink relay or NR V2X). A solution is sought. Summary of the Invention

[0007] A method for UE prioritization and multiplexing of sidelink relay data for simultaneous LCP procedures in an NR system is proposed. The UE divides traffic into different categories based on traffic direction, ownership, and the interface used. The UE can configure a specific priority order for some or all traffic categories so that when the UE has traffic from multiple traffic categories to send simultaneously, the UE can prioritize those traffic categories with higher class priorities based on the class priority order. The sidelink relay traffic prioritization is then used for transmission interface and resource selection, and / or data multiplexing prioritization based on the sidelink relay architecture. Specifically, a method is provided on how to perform corresponding LCP operations for MAC PDU multiplexing. LCP restrictions need to be considered to determine which traffic categories can be multiplexed together into the same MAC PDU. The multiplexing priority also needs to be applied to determine the order and number of traffic to be included in the MAC PDU.

[0008] In one embodiment, a transmitter UE (e.g., a relay UE) establishes multiple sidelink logical channels (LCHs) for sidelink communication. Multiple LCHs are associated with data transmitted by the UE. The relay UE determines the LCH with the highest priority service. This determination is based at least on the service category of each service. The service category is determined based on the service direction, service owner, and transmission interface. The relay UE selects an LCH that has available data and is allowed to be multiplexed with the highest priority LCH to construct a MAC PDU for transmission. The relay UE sends the MAC PDU on the resources allocated for the selected LCH. Resources are allocated to construct the MAC PDU by multiplexing the data from the selected LCH in a multiplexing order.

[0009] According to the logical channel priority sorting method and user equipment supporting side link relay provided by the present invention, by performing corresponding logical channel priority sorting, it can be ensured that higher priority services on the side link relay can be sent with higher priority.

[0010] Other embodiments and advantages are described in the detailed description that follows. This summary is not intended to define the invention. The invention is defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Illustrated is a wireless communication system with LCP enhancements to support sidelink relaying in accordance with novel aspects.

[0012] Figure 2 is a simplified block diagram of a wireless transmitting device and a receiving device in accordance with novel aspects.

[0013] Figure 3 The diagram illustrates an example of different services with sidelink relay, uplink, and downlink between a base station, a relay UE, and a remote UE in an NR network.

[0014] Figure 4 An example of determining service priorities based on service categories is illustrated.

[0015] Figure 5 A first step of traffic prioritization of determining highest priority traffic from different traffic classes according to one novel aspect is illustrated.

[0016] Figure 6 A second step of resource selection based on determined highest priority traffic in accordance with one novel aspect is illustrated.

[0017] Figure 7 Illustrated is a third step of LCP restriction for multiplexing data into the same MAC PDU in accordance with one novel aspect.

[0018] Figure 8 A fourth step of data multiplexing prioritization that determines the order and number of MAC PDUs according to one novel aspect is illustrated.

[0019] Figure 9 is a flow chart of an LCP enhancement method for supporting sidelink relay according to one novel aspect. DETAILED DESCRIPTION

[0020] Reference will now be made in detail to some embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[0021] Figure 1 Illustrated is a wireless communication network 100 supporting enhancements for sidelink LCP for a sidelink in accordance with novel aspects. Figure 1 This is an example of sidelink relay, where remote UE 104 communicates with base station gNB 101 via the sidelink relay of relay UE 102 (UE A) and relay UE 103 (UE B). A relay UE is a UE responsible for forwarding Uu traffic from other UEs / base stations to the base station / other UEs. In contrast, a remote UE is a UE whose Uu traffic is relayed via a relay UE. A relay UE that can communicate directly with the base station via the Uu interface is called a UE-to-NW relay, meaning that the relay forwards traffic directly to the network via the Uu interface. Furthermore, UE A is an upstream relay UE of relay UE B because its data is forwarded via relay UE A and relay UE A is closer to the base station (one hop) than relay UE B. Similarly, UE B is a downstream relay UE of relay UE A because relay UE B is closer to the remote UE (one hop) than relay UE A.

[0022] In a sidelink communication scenario for relaying (i.e., sidelink relaying), from the perspective of the transmitter UE, sidelink traffic can be classified based on (1) traffic direction, (2) traffic owner, and (3) transmission interface. In sidelink relaying, the traffic direction can be uplink (UL) (i.e., traffic for uplink, forwarded to the gNB), downlink (DL) (i.e., traffic for downlink, forwarded to a remote UE or another relay UE), and sidelink (SL) (i.e., traffic will be forwarded to another peer UE via a base station or network node on the routing path without relaying). From the perspective of the transmitter UE, the traffic owner can be the transmitter UE itself or another UE (i.e., the transmitter UE relays data for other remote UEs or other UE-to-UE relays). The transmission interface refers to the link from the transmitter UE to the next-hop UE / gNB, which can be a Uu interface or a PC5 interface. A UE-to-NW relay UE can communicate directly with the base station via the Uu interface, while a UE-to-UE relay UE or remote UE may not have an available Uu interface. In a UE-to-Network relay, a remote UE can communicate with at least one relay UE via a PC5 interface.

[0023] Service prioritization and multiplexing within the UE are performed in the MAC layer. The UE first selects data from logical channels (LCH) associated with different priorities and multiplexes them into a single MAC PDU. The UE then transmits the MAC PDU to the physical (PHY) layer for transmission. In sidelink communication, transmission interface selection and data multiplexing require priority sorting rules. For example, the UE may have uplink and sidelink transmissions to be sent on different interfaces at the same time. If the UE cannot send data on both interfaces at the same time, the UE needs to do service prioritization, that is, select one of the UL services and SL services with higher transmission priority. In another example, the relay UE may have its own UL services and UL services from the remote UE for relaying at the same time. In this case, although the UL services from the relay UE itself and the UL services from the remote UE are both sent via the Uu interface, the relay UE still needs a clear priority sorting rule to determine the order of data multiplexing, that is, which data can be placed in the available UL grant priority.

[0024] According to a novel aspect, a method for service prioritization for sidelink relay in a UE is provided. The UE differentiates service types within itself into different categories based on service direction, ownership, and interface used. The UE may configure a specific priority order for some or all service categories so that when the UE has services from multiple service categories to send simultaneously, the UE may provide priority ordering for service categories with higher class priorities based on the class priority order. The UE may further differentiate services within the same category into high priority services and low priority services based on one or more thresholds. The one or more thresholds may be configured / preconfigured by the network via dedicated RRC signaling, SIB, or pre-configuration. The UE prioritizes high priority services over low priority services. The UE prioritizes certain service types over other service types based on priority levels.

[0025] The sidelink relay service prioritization is then used for transmission interface and resource selection, and / or data multiplexing prioritization based on the sidelink relay architecture. Therefore, a method is provided to determine whether multiplexing is supported when sidelink relay data from different remote UEs are present simultaneously, or when sidelink relay data and NR-V2X services are present simultaneously. Specifically, a method is provided for how to perform corresponding LCP operations for MAC PDU multiplexing. LCP restrictions need to be considered to determine which service categories can be multiplexed together into the same MAC PDU. LCP restrictions include whether to allow multiplexing of data from sidelink logical channels with services from different source UEs, from different next-hop UEs and / or belonging to different service categories. Multiplexing priority needs to be applied to determine the order and number of services to be included in the MAC PDU. The priority depends on one or more of the following factors: (1) logical channel priority; (2) logical channel priority level; (3) associated service category; (4) Bj, which identifies the amount of service that should be sent to meet the transmission rate requirement; and (5) delay or QoS related parameters.

[0026] exist Figure 1 In an example, a four-step method is proposed for prioritizing and multiplexing sidelink relay data for simultaneous UE sidelink LCP procedures in NR sidelink relay. In step 1 (111), the UE performs service prioritization to determine the highest priority service from different service categories (classifications) for transmission. In step 2 (112), the UE selects transmission resources based on the determined highest priority service. In step 3 (113), the UE applies LCP restrictions to determine which service categories can be multiplexed into the same MAC PDU with the highest priority service. In step 4 (114), the UE determines the priority of data multiplexing, e.g., the order and number of services to be included on the MAC PDU for transmission.

[0027] Figure 2FIG2 is a simplified block diagram of wireless devices 201 and 211 according to novel aspects. For wireless device 201 (e.g., a base station or relay UE), antennas 207 and 208 transmit and receive radio signals. RF transceiver module 206 is coupled to the antennas, receives RF signals from the antennas, converts them to baseband signals, and transmits the baseband signals to processor 203. RF transceiver 206 also converts baseband signals received from the processor, converts them to RF signals, and transmits them to antennas 207 and 208. Processor 203 processes the received baseband signals and invokes various functional modules and circuits to execute features within wireless device 201. Memory 202, including both volatile and non-volatile computer-readable storage media, stores program instructions and data 210 to control the operation of device 201.

[0028] Similarly, for wireless device 211 (e.g., a remote user device), antennas 217 and 218 transmit and receive RF signals. RF transceiver module 216, coupled to the antennas, receives RF signals from the antennas, converts them to baseband signals, and transmits the baseband signals to processor 213. RF transceiver 216 also converts baseband signals received from the processor, converts them to RF signals, and transmits them to antennas 217 and 218. Processor 213 processes the received baseband signals and invokes various functional modules and circuits to execute features within wireless device 211. Memory 212, which includes both volatile and nonvolatile computer-readable storage media, stores program instructions and data 220 to control the operation of wireless device 211.

[0029] Wireless devices 201 and 211 also include several functional modules and circuits that can be implemented and configured to perform embodiments of the present invention. Figure 2In the example of FIG. 2 , wireless device 201 is a relay or TX UE and includes a protocol stack 222, resource management circuitry 205 for allocating and scheduling sidelink resources, an LCP processing module 204 for executing LCP with LCP restrictions and priority multiplexing, a connection / LCH processing circuitry 209 for establishing connections and logical channels with a base station and a remote UE, and a control and configuration circuitry 221 for providing control and configuration information. Wireless device 211 is a remote or RX UE and includes a protocol stack 232, synchronization processing circuitry 215, a relay discovery circuitry 214 for discovering relay UEs, a connection processing circuitry 219 for establishing sidelink connections, and a configuration and control circuitry 231. The various functional modules and circuitry may be implemented and configured using software, firmware, hardware, or any combination thereof. When executed by processors 203 and 213 (e.g., by executing program code 210 and 220), the functional modules and circuitry enable relay UE 201 and remote UE 211 to perform embodiments of the present invention in accordance with the present invention. In one example, when UE 201 has traffic from more than one traffic class to send simultaneously, the relay UE 201 provides traffic prioritization based on the traffic class. The sidelink relay traffic prioritization is then used for transmission interface and resource selection, as well as data multiplexing prioritization based on the sidelink relay architecture.

[0030] Figure 3 An example of different services with sidelink relay, uplink, downlink between a base station, a relay UE, and a remote UE in an NR network 300 is illustrated. The basic NR UE to network relay architecture 300 includes a base station gNB 301, a relay UE 302, and a remote UE 303. From the perspective of a transmitter UE, such as the relay UE 302, the sidelink services can be classified based on three classification criteria (as depicted in 330): (1) service direction (UL, DL, or SL), (2) service owner (UE itself or other UE), and (3) transmission interface (Uu interface, or sidelink PC5 interface). Figure 3 In the example of , for the service depicted by 310, it can be the relay UE's own service on the Uu interface or PC5 or the UL relay of the remote UE 303. For the service depicted by 320, it can be the relay UE's own service, or the DL relay of the remote UE 303, or the SL relay of the remote UE303.

[0031] Based on three classification criteria, there are seven valid service categories: (1) UL services of the transmitter UE itself via the Uu interface (UL-Self-Uu), (2) UL services of the transmitter UE itself via the PC5 interface (UL-Self-PC5), (3) UL services relayed by other UEs via the Uu interface (UL-Other-Uu), (4) UL services relayed by other UEs via the PC5 interface (UL-Other-PC5), (5) DL services relayed by other UEs via the PC5 interface (DL-Other-PC5), (6) SL services (such as NR-V2X services or LTE-V2X services) of the transmitter UE itself via PC5 (SL-Self-PC5), and (7) SL services (such as NR-V2X services) relayed by other UEs via PC5 (SL-Other-PC5).

[0032] Figure 4 The figure shows an example of determining service priority based on service categories. The UE can be configured with a specific priority order for some or all service categories. Figure 4 In the example, four simplified service categories, e.g., UL, UL relay, DL relay, and DL, are compared with different priority rules. In the first application scenario (410), relay service takes precedence over the relay UE's own service, e.g., DL relay = UL relay > UL > SL. In the second application scenario (420), UL / DL service takes precedence over SLV2X service, e.g., DL relay = UL relay = UL > SL. In the third application scenario (430), the Uu interface takes precedence over the PC5 interface, e.g., UL = UL relay > DL relay > SL.

[0033] Figure 5 The first step of service prioritization according to one novel aspect is illustrated to determine the highest priority service from different service categories. Figure 3 As shown, there are seven valid service classes, as shown in 510, based on the service direction, owner, and interface used. Each service class has its own priority level. For example, Uu services have 16 different priority levels, and sidelink services have 8 different priority levels. To determine the priority of these services, a mechanism is required to directly or indirectly compare their priority levels. Mapping rules can be used to compare the priorities of services belonging to different service classes, as shown in 520.

[0034] In one embodiment of direct comparison, for service categories to be sent in the same transmission interface (e.g., PC5), priority sorting can be performed based on a direct comparison of the sidelink logical channel priority or the priority value indicated in the sidelink control information (SCI). That is, if two service categories are sent on the same interface, but belong to Uu and SL services respectively, we can compare the priorities of the mapped logical channels on this interface. For example, for DL ​​relay services and V2X services sent on the PC5 interface, we can compare the priorities of the SLLCH. That is, although the DL relay service is a Uu service, it will be mapped to the SL logical channel when sent on the PC5 interface. Therefore, the DL relay Uu service will have equal SLLCH priority for priority comparison.

[0035] In one embodiment of direct comparison, for service categories to be sent in the same transmission interface (e.g., PC5), priority sorting can be performed based on a direct comparison of the sidelink logical channel priority with the service owner. For example, there is an SLLCH priority threshold to determine whether the sidelink service from the relay UE itself is high priority or low priority, and there is another SL LCH priority threshold to determine whether the sidelink service from one or more remote UEs is high priority or low priority. The relay UE first divides the sidelink service into four categories, and then determines the priority based on the priority order of the categories, for example (from relay, high priority) > (from remote, high priority) > (from relay, low priority) > (from remote, low priority). The same logic can be applied to Uu transmission when the relay has UL data from itself and from remote UEs for priority comparison.

[0036] In one embodiment of direct comparison, for traffic classes belonging to Uu traffic, prioritization can be performed based on a direct comparison of Uu LCH priorities (e.g., 16 LCH priority levels). In other words, if two traffic classes both belong to Uu but are sent on different interfaces, their Uu priorities can be directly compared. For example, UL relay traffic on Uu versus DL relay traffic on PC5. The LCH priority of the relay traffic can be mapped to the Uu priority for priority comparison.

[0037] In another embodiment of direct comparison, for services belonging to Uu services and sidelink services (e.g., for NR V2X), priority sorting can be performed based on a conversion or mapping function across UL services and SL services. That is, if two services are sent on different interfaces, belonging to Uu and PC5 services respectively, a predefined priority sorting rule can be used to determine the priority, regardless of whether the service comes from the relay UE itself or from a remote UE, for example, a UuLCH priority threshold is used to determine whether the Uu service under consideration is Uu high priority or Uu low priority, a sidelink LCH priority threshold is used to determine whether the SL service under consideration is SL high priority or SL low priority, and then the priority is determined in the order of Uu high priority, SL high priority, Uu low priority, and SL low priority.

[0038] Figure 6 The second step of resource selection based on the determined highest priority traffic according to one novel aspect is illustrated. The UE may be configured (by the NW or by the scheduler UE) with uplink / sidelink dedicated resources (610). For example, the resources are dedicated to traffic generated by the UE, rather than to relayed traffic from other UEs; the resources are dedicated to Uu traffic (from or to the gNB), rather than to sidelink traffic (from the UE and to another UE); and the resources are dedicated to relayed traffic, rather than to non-relayed traffic.

[0039] The dedicated resource configuration may be configured explicitly or implicitly. Explicitly, for example, a UL configured grant or a SL configured grant may be configured in the relevant RRC message / MAC CE bit / DCI field upon activation to indicate whether the configured grant is dedicated to the service owner, service type (Uu vs. non-Uu), or relay vs. non-relay. Different configured grants may be associated with different resource configurations. In another example, it is indicated in the DCI that the UL dynamic grant or the SL dynamic grant is dedicated to the service owner. Implicitly, for example, certain resources or resource pools are configured as dedicated to relay data. The resources selected by the UE from the relay dedicated resource pool may only be used to send relay data.

[0040] In one embodiment, the network may configure dedicated resources for the UE to send relay data. For uplink transmission, if the highest priority service is relay data, the UE should select a UL grant belonging to dedicated resources for relaying. The UE cannot select UL resources that are not dedicated resources for relaying to carry the highest priority service. For sidelink transmission, if the highest priority service is relay data, the UE should select a SL grant belonging to dedicated resources for relaying. The UE cannot select SL resources that are not dedicated resources for relaying to carry the highest priority service.

[0041] In one embodiment, if the radio resources are not relay-specific, the UE can use the radio resources to carry relay traffic or non-relay traffic. In one embodiment, if the radio resources are not relay-specific, the UE cannot use the radio resources to carry non-relay traffic. In one embodiment, if the radio resources are relay-specific, the UE can use the radio resources to carry only relay traffic and not non-relay traffic.

[0042] In one embodiment, if radio resources are not dedicated to relaying but are prioritized / deprioritized for relaying, the UE can use the radio resources to carry either relay traffic or non-relay traffic. This radio resource configuration is taken into account during the LCP process. For example, if resources are prioritized for relay traffic, the UE will only multiplex non-relay data after all LCHs with relay data have no more data available for transmission.

[0043] In one embodiment, if the radio resources are not specific to Uu traffic, the UE may use the radio resources to carry Uu traffic or sidelink traffic (e.g., for NR-V2X applications). In one embodiment, if the radio resources are not specific to sidelink traffic, the UE may use the radio resources to carry Uu traffic (UL / DL traffic) or sidelink traffic (e.g., for NR-V2X applications).

[0044] In one embodiment, if the radio resources are not specific to Uu traffic, the UE cannot use the radio resources to carry Uu traffic. In one embodiment, if the radio resources are not specific to sidelink traffic, the UE cannot use the radio resources to carry sidelink traffic.

[0045] In one embodiment, if radio resources are not dedicated to Uu traffic but are prioritized / deprioritized for Uu traffic, the UE can use these radio resources to carry Uu traffic or sidelink traffic. The configuration of these radio resources is taken into account during the LCP process. For example, if the resources are prioritized for Uu traffic, the UE will only multiplex the sidelink traffic after all LCHs with Uu traffic data have no more data available for transmission.

[0046] Figure 7The third step of LCP restriction for multiplexing data into the same MAC PDU according to one novel aspect is illustrated. As shown in 710, LCP / data multiplexing from LCP restriction takes into account the following factors: (1) the service source UE, (2) the next hop relay UE (including whether the next hop is a base station or a source UE), and (3) the service category of each logical channel. From the perspective of hops, the routing path of the relay consists of five categories of hops, as shown in 720. Hop 1: hop from relay UE to another relay UE, Hop 2: hop from remote UE to relay UE, Hop 3: hop from relay UE to remote UE, Hop 4: hop from relay UE to base station, Hop 5: hop from base station to relay UE. From the perspective of the service source and next hop UE, for each transmitter UE, the service to be sent in a single service category can be further divided into 4 scenarios, as shown in 730. Category 1 scenario - same source UE and same next-hop relay, Category 2 scenario - same source UE but different next-hop UE, Category 3 scenario - different source UE and same next-hop relay, and Category 4 scenario - different source UE and different next-hop relay.

[0047] Based on the hop type and whether the UE supports repeated relaying to multiple next-hop UEs, the UE may apply LCP restriction rules, i.e., services from different service source UEs and / or to be forwarded to different next-hop relay UEs can or cannot be multiplexed into the same MAC PDU. In addition, services from multiple different service categories may or may not be multiplexed into the same MAC PDU. For example, it may be allowed to multiplex UL services from the transmitter UE itself and UL services for relaying from other UEs; but it may not be allowed to multiplex Uu relay services and SL relay services into the same MAC PDU, for example if the network configures separate resources, resource pools or configured authorizations for relay services and sidelink services (e.g., for NR-V2X).

[0048] In one example, if two services come from different next-hop UEs, it is preferred that they are not multiplexed into the same MAC PDU. In one example, if two services come from different source UEs, it is preferred that they are multiplexed into the same MAC PDU to increase resource utilization. In another example, the services of SL relay and SL V2X should not be multiplexed into the same MAC PDU through the PC5 interface in order to decouple the services of V2X and relay. In yet another example, the services for SL relay and the Uu services for relay UE can be multiplexed into the same MAC PDU through the Uu interface to increase resource utilization. In another example, if resources are dedicated to relay / non-relay services, Uu / non-Uu services, or UE's own services / services from other UEs (as we mentioned in step 1.5), the UE should only select those logical channels that meet the restrictions on multiplexing the selected resources. In yet another example, whether SL relay data can be multiplexed with other services also depends on the detailed content of the relay service, for example, if the packet is used for SL relay discovery, it may not be multiplexed with any other SL relay data.

[0049] Figure 8 The fourth step of data multiplexing prioritization that determines the order and number of MAC PDUs according to a novel aspect is illustrated. When the TX UE creates a MAC PDU to transmit using the allocated radio resources, the TX UE aims to meet the QoS of each configured radio bearer. The TX UE must decide the amount of data for each LCH to be included in the MAC PDU. When constructing a MAC PDU using data from multiple LCHs, the data from the highest priority LCH is provided first in the MAC PDU, followed by the data from the next highest priority LCH, and so on until the MAC PDU space is exhausted. The resource allocation LCP process for SLLCHs consists of two rounds: in the first round - resources are allocated in order of decreasing priority to meet Bj (from high priority SL LCH to low priority SL LCH); and in the second round - resources are allocated to clear all remaining data in order of decreasing priority until the SL resources granted for this SL are exhausted or until no SL LCH has remaining data. SL LCHs configured with the same priority should be served equally.

[0050] Several parameters may be considered to determine how to allocate resources for uplink / sidelink grants, as shown in 810: 1) logical channel priority (the method for comparing logical channel priorities was mentioned earlier, which takes into account both the priority value of the logical channel and the service category to which the logical channel belongs), 2) logical channel priority value, 3) related service category, 4) Bj (identifies the amount of service that should be sent to meet the transmission rate requirement or prioritized bit rate (prioritized BitRate), and 5) delay or QoS related parameters, such as packet delay budget (PDB) or the number of relay hops of the source UE. In addition, the UE may further consider the configuration / attributes of the uplink grant / sidelink grant. For example, the uplink grant / sidelink grant may prioritize a certain service characteristic, for example, prioritizing / deprioritizing relay services over non-relay services. The radio resource priority information (i.e., uplink grant or sidelink grant) can be indicated / provided by the base station in one of the RRC messages, MAC CE or DCI, or can be provided by the scheduler UE in one of the PC5-RRC messages, sidelink MAC CE or SCI (Sidelink Control Information). In the data multiplexing process, one or more of the above parameters are taken into account.

[0051] In one embodiment of the data multiplexing process, each LCH is scheduled using resources based only on the descending order of logical channel priority. In another embodiment, the logical channel priority can be a joint consideration of the logical channel priority value and the service category, including (1) whether the service is from the UE or used to relay services from other UEs, (2) the transmission interface, and (3) whether the service belongs to Uu or SL communication (for example, for V2X). In another embodiment, the order of determining the priority of resource allocation can be Bj=>service category=>LCH priority. First, the UE selects the LCH with Bj>0; second, the LCH for Uu service takes precedence over the LCH for relay service; third, the UE compares the logical channel priorities.

[0052] The priority order of service classes can be determined by the network. Example 1: Based on the selected resources (e.g., via RRC configuration or via the resource pool used), as in step 2. Example 2: A uniform service class priority order is provided regardless of the selected resources. Example 3: This can be either Example 1 or Example 2, depending on different scenarios, such as whether it is dynamic authorization or configuration authorization, whether the NW has configured a relay-dedicated resource pool, whether the logical channel priority of the relevant service class is high, or whether the message / information to be sent in the relevant service class has a special purpose.

[0053] Figure 99. The present invention relates to a flow chart of an LCP enhancement method for supporting sidelink relay according to a novel aspect. In step 901, a transmitter UE (e.g., a relay UE) establishes multiple LCHs for sidelink communication. The multiple LCHs are associated with data transmitted by the UE. In step 902, the UE determines the LCH with the highest priority service. The determination is based on at least the service category of each service. The service category is determined based on the service direction, service owner, and transmission interface. In step 903, the UE selects an LCH that has available data and is allowed to be multiplexed with the highest priority LCH to construct a MAC PDU for transmission. In step 904, the UE sends a MAC PDU on the resources allocated for the selected LCH. Resources are allocated to construct a MAC PDU by multiplexing data from the selected LCH in a multiplexing order.

[0054] Although the present invention has been described in conjunction with certain specific embodiments for guiding purposes, it is not limited thereto. Therefore, various modifications, amendments and combinations of the various features of the described embodiments may be implemented without departing from the scope of the invention as set forth in the claims.

Claims

1. A method for prioritizing logical channels in support of sidelink relay, comprising: establishing, by a transmitter user equipment, a plurality of sidelink logical channels (LCHs) for sidelink communication, wherein the plurality of LCHs are associated with data transmitted by the user equipment; determining an LCH having the highest priority service, wherein the determining is based on at least a service class of each service, and wherein the service class is determined based on a service direction, a service owner, and a transmission interface; selecting an LCH having available data and allowing multiplexing with the highest priority LCH to construct a MAC PDU for transmission, wherein the LCH is selected based on a service source user equipment, a next hop relay user equipment, and a service category of each LCH; as well as The MAC PDU is transmitted on resources allocated for the selected LCH, wherein the resources are allocated to construct the MAC PDU by multiplexing data from the selected LCH in a multiplexing order.

2. The method according to claim 1, characterized in that The service direction includes uplink, downlink and sidelink, the service owner includes the user equipment itself and other user equipments, and the transmission interface includes a Uu interface and a sidelink interface.

3. The method according to claim 1, characterized in that The highest priority traffic is determined by mapping traffic priorities to equal LCH priorities corresponding to the transport interface.

4. The method according to claim 1, wherein The highest priority LCH is determined based on at least one of an LCH priority, an LCH priority level, a service category, a traffic volume meeting a transmission rate requirement, and a QoS parameter.

5. The method according to claim 1, wherein Traffic from different source user equipments may be multiplexed, and wherein traffic with different next-hop user equipments cannot be multiplexed to form the same MAC PDU.

6. The method according to claim 1, characterized in that The user equipment is configured with dedicated resources based on service direction, service owner and transmission interface.

7. The method according to claim 6, characterized in that The user equipment selects dedicated resources according to the determined highest priority service.

8. The method according to claim 1, characterized in that The multiplexing order is determined based on at least one of LCH priority, LCH priority level, service category, traffic volume meeting transmission rate requirements, QoS parameters of the corresponding LCH, and prioritized service characteristics specific to the allocated resources for MAC PDU transmission.

9. The method according to claim 8, characterized in that The multiplexing order is determined by a joint consideration of the LCH priority value and the service class.

10. A transmitter user equipment supporting logical channel prioritization for sidelink relay, comprising: a logical channel (LCH) processing circuit, configured to establish a plurality of sidelink LCHs for sidelink communication, wherein the plurality of LCHs are associated with data transmitted by the user equipment; a control circuit configured to determine an LCH having a highest priority service, wherein the determination is based on at least a service class of each service, and wherein the service class is determined based on a service direction, a service owner, and a transmission interface; a logical channel prioritization (LCP) processing circuit configured to select an LCH having available data and allowing multiplexing with the highest priority LCH to construct a MAC PDU for transmission, wherein the LCH is selected based on a service source user equipment, a next hop relay user equipment, and a service category of each LCH; as well as A transmitter is configured to transmit the MAC PDU on resources allocated for the selected LCH, wherein the resources are allocated to construct the MAC PDU by multiplexing data from the selected LCH in a multiplexing order.

11. The user equipment according to claim 10, wherein: The service direction includes uplink, downlink and sidelink, wherein the service owner includes the user equipment itself and other user equipments, and wherein the transmission interface includes a Uu interface and a sidelink interface.

12. The user equipment according to claim 10, wherein: The highest priority traffic is determined by mapping traffic priorities to equal LCH priorities corresponding to the transport interface.

13. The user equipment according to claim 10, wherein: The highest priority LCH is determined based on at least one of an LCH priority, an LCH priority level, a service category, a traffic volume meeting a transmission rate requirement, and a QoS parameter.

14. A transmitter user equipment supporting logical channel prioritization for sidelink relay, comprising: A processor is coupled to a memory, wherein the memory stores program instructions and data, and when the program instructions and data are executed by the processor, the user equipment performs the operation described in any one of claims 1 to 9 above.

15. A non-volatile computer-readable storage medium storing program instructions and data, which, when executed by a processor of a transmitter user equipment that supports logical channel priority sorting for sidelink relay, enables the user equipment to perform the operations described in any one of claims 1 to 9 above.

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