TWI816496B - Methods and user equipment for wireless communication - Google Patents

Abstract

A method for wireless communication, comprising: receiving a recommended bit rate query message from a remote UE, wherein the message is carried by a control signaling or by a sidelink MAC control element (SL MAC CE) dedicated for the remote UE; forwarding the recommended bit rate query message to a base station over Layer-2 sidelink relay when the message is carried by the control signaling; and forwarding the recommended bit rate query message to the base station when the message is carried by the SL MAC CE, wherein the SL MAC CE has a unique SL logical channel ID (SL LCID) value that indicates the recommended bit rate query message.

Description

Methods and user equipment for wireless communications

The present invention relates to wireless network communications, and in particular refers to UE to network relay (UE- to-Network Relay) to realize end-to-end media storage between remote user equipment (User Equipment, UE) (remote UE) and next generation Node B (gNB) Take the control (Media Access Control, MAC) control unit (Control Element, CE) transmission.

New technologies in 5G NR allow cellular devices to connect directly to each other using a technology called SideLink (SL) communication. Sidelink is a new communications paradigm in which cellular devices are able to communicate without relaying their data through the network. The sidelink interface may also be called the PC5 interface. Various applications can rely on communication on the side link interface, such as Vehicle-to-everything (V2X) communication, Public Safety (PS) communication, direct file transfer between user devices, etc. To support sidelink relay, there are two UE-to-network relay architectures, namely Layer 2 (L2) relay and Layer 3 (L3) relay.

In the case of L3-based sidelink relay, the relay UE serves as a general router in the data communication network and forwards the data packet flow of the remote UE as an Internet Protocol (IP) service. ). Forwarding of IP-based services is performed in a best-effort manner. For L3 UE to network relay, there are both Sidelink Radio Bearer (SLRB) and Uu radio bearer on PC5 to carry the connection between the remote UE and the 5G Core (5G Core, 5GC) Established Quality of Service (QoS) flow. L3 UE to network relay can support flow-based mapping at the Service Data Adaptation Protocol (SDAP) layer when converting PC5 flows to Uu flows during service forwarding and vice versa. Please note that since the L3-based sidelink relay UE works like an IP router, the remote UE is transparent to the gNB, that is, the gNB cannot know that the service transmitted by the relay UE originates from the relay UE itself. Or originated from the remote UE but forwarded by the relay UE.

In contrast, in the case of L2-based SL relaying, relaying is performed above the Radio Link Control (RLC) sublayer via the relaying UE for the control plane between the remote UE and the network ( Control Plane, CP) and User Plane (User Plane, UP). Uu SDAP/Packet Data Convergence Protocol (PDCP) and Radio Resource Control (RRC) are terminated between the remote UE and gNB, while the RLC, MAC and physical (Physical, PHY) layers are terminated in two links (i.e., the link between the remote UE and the UE to the network relay UE and the link between the UE and the network relay UE and the gNB). Uu supports the adaptation layer on the RLC layer for bearer mapping, and the adaptation layer can also be located on PC5 for bearer mapping on the sidelink. The adaptation layer between the relay UE and the gNB can distinguish the bearers of specific remote UEs (Signaling Radio Bearer (SRB), Data Radio Bearer (DRB)). Within a Uu DRB, different remote UEs and different bearers of the remote UE may be indicated by additional information contained in the adaptation layer header (header). Unlike L3 relay, gNB knows each remote UE, so before the relay UE starts forwarding normal data services, an end-to-end connection between the remote UE and gNB is first established. After the RRC connection is established through the SL relay, the remote UE can then forward data services based on the established bearer and the forwarding/router information carried by the adaptation layer.

In NR, in order to enhance the Multimedia Telephony (MMTEL) IP Multimedia Subsystem (IMS) voice and video, Radio Access Network (RAN)-assisted codec adaptation is introduced. RAN-assisted codec adaptation provides gNB with a method to send codec adaptation indication using the recommended bit rate to assist the UE in selecting or adapting the codec rate for MMTEL voice or MMTEL video. . The RAN-assisted codec adaptation mechanism supports the increase or decrease of uplink/downlink bit rates. For bearers associated with a configuration where the Maximum Bit Rate (MBR) is greater than the Guaranteed Bit Rate (GBR), the recommended upstream/downstream bit rates are set by the MBR and GBR of the associated bearer. within the boundaries.

For uplink or downlink bit rate adaptation, the gNB can send the recommended bit rate to the UE to inform the UE of the current recommended transmission bit rate on the local uplink or downlink. The UE can use it in combination with other information to adapt. Bit rate, for example, the UE can send a bit rate request to the peer UE through an application layer message, and the peer UE can use it in conjunction with other information to adapt the codec bit rate. When making decisions, the recommended bit rate is in kbps at the PHY layer.

The recommended bit rates for uplink (UL) and downlink (DL) are conveyed from the gNB to the UE as MAC CE. Based on the recommended bit rate from the gNB, the UE can initiate end-to-end bit rate adaptation with the peer (UE or Media Gateway (MGW)). The UE can also send a query message to its local gNB to check whether the gNB can provide the bit rate recommended by the peer. The UE is not expected to exceed the gNB recommended bit rate. The query message for the recommended bit rate is passed from the UE to the gNB as a MAC CE.

MAC CE does not support SL relay forwarding. Most MAC CEs are used to manage the link between UE and gNB. However, a few MAC CEs are not used for link management, including (1) bit rate query and recommended MAC CEs and (2) UL buffer status report (Buffer Status Report, BSR). Current SL relay designs do not support MAC CE forwarding, so the remote UE cannot inform the gNB of its preferred bit rate and buffer contents.

A solution needs to be found.

Methods may be provided to support the remote UE in transmitting a recommended bit rate query to the base station through processing by the relay UE. In a novel aspect, a new sidelink MAC CE may be introduced to indicate the desired bit rate for a specific sidelink logical channel or a specific Uu/SL radio bearer. In a novel aspect, after receiving the recommended bit rate query MAC CE, the relay UE can add the information related to the remote UE identity (Identity, ID) through the Uu interface. forwarded to the base station. In a novel aspect, when a relay UE receives a recommended bit rate query MAC CE, the MAC CE can be mapped to a specific uplink logical channel priority (LCP) value or a specific uplink logical Channel priority level for priority comparison with other UL profiles or UL MAC CE.

Methods for the base station to transmit the recommended bit rate to the remote UE may also be provided. In a novel aspect, the remote UE's recommended bit rate MAC CE may be transmitted from the base station to the relay UE along with the remote UE's ID. In a novel aspect, after the relay UE receives the recommended bit rate MAC CE, the relay UE may forward the MAC CE to the target remote UE based on the associated remote UE ID. In a novel aspect, the recommended bit rate MAC CE may have a fixed or configured sidelink logical channel priority value, and/or an associated priority value that can be compared to other SL profiles and SL MAC CEs.

A method for wireless communication, executed by a relay user equipment, the method includes: receiving a recommended bit rate query message from a remote user equipment, wherein the message is provided by a control signaling or by the carried by the remote user equipment-specific sidelink media access control control unit; when the recommended bit rate query message is carried by the control signaling, it is carried through the layer 2 sidelink relay Forwarding the recommended bit rate query message to a base station; and when the control unit of the sidelink media access control carries the recommended bit rate query message, forwarding the recommended bit rate query message The query message is forwarded to the base station, wherein the control unit of sidelink media access control has a unique sidelink logical channel identification value, and the sidelink logical channel identification value indicates the recommendation Bit rate query message.

A method for wireless communication, performed by a relay user equipment, the method includes: receiving a recommended bit rate message from a base station, wherein the message is carried by a control signaling or by a remote user The device-specific downlink media access control control unit is carried; when the recommended bit rate information is carried by the control signaling, the recommended bit rate information is transmitted through the layer 2 sidelink relay Forwarding to the remote user equipment; and when the recommended bit rate message is carried by the control unit of the downlink media access control, forwarding the recommended bit rate message to the remote user equipment The device, wherein the control unit of downlink media access control has a downlink logical channel identification value, and the downlink logical channel identification value indicates the recommended bit rate information.

A relay user equipment for wireless communication, including: a receiver that receives a recommended bit rate query message from a remote user equipment, wherein the message is sent by a side link dedicated to the remote user equipment. carried by the control unit of the channel media access control, wherein the receiver receives a recommended bit rate message from a base station, wherein the message is carried by the remote user equipment-specific downlink media access control a control unit to carry; and a relay processing circuit to forward the recommended bit rate query message to the base station, wherein the control unit of the sidelink media access control has a unique sidelink Logical channel identification value, the side link logical channel identification value indicates the recommended bit rate query message, wherein the relay processing circuit forwards the recommended bit rate message to the remote user equipment , wherein the control unit of downlink media access control has a downlink logical channel identification value, and the downlink logical channel identification value indicates the recommended bit rate information.

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

Figure 1 may illustrate a wireless mobile communication system 100 supporting uplink and downlink MAC CE forwarding through SL relays according to novel aspects. The 5G NR mobile communication network 100 may include a 5GC 101, a next generation base station gNB 102 and A plurality of user equipments UE 103, UE 104 and UE 105. For UEs within coverage, the base station can schedule data services through the Uu link. For UEs outside the coverage area, the relay UE can schedule data services through PC5 (or sidelink). In Figure 1, UE 103 is an RRC connected UE, which can be used as a mobile device relay to use PC5 (or SL) to relay data services sent to/from the terminal remote UE for coverage expansion. The remote UE 104 may not be within network coverage. The relay UE 103 can help relay all data services of the remote UE 104. The remote UE 105 can connect to the network through the Uu link, but the link quality may be poor. The relay UE 103 may relay some or all of the data services of the remote UE 105. Relay UE 103 may be used to relay communications between UE 104/105 and the network, thereby allowing the network to effectively extend its coverage to remote UEs.

To support sidelink relay, there are two UE-to-network relay architectures, namely layer 2 relay (L2 relay) and layer 3 relay (L3 relay). However, MAC CE does not support SL relay forwarding. Although most MAC CEs are used to manage the link between UE and gNB, a few MAC CEs are not used for link management, including (1) bit rate query and recommendation MAC CE and (2) UL BSR. For example, the recommended bit rates for uplink and downlink can be transmitted from gNB to UE as MAC CE, and the recommended bit rate query message can be transmitted from UE to gNB as MAC CE. However, current SL relay designs do not support MAC CE forwarding.

According to a novel aspect, a method may be proposed to allow uplink and downlink MAC CE forwarding through sidelink relays. As shown in Figure 1, in the uplink, the recommended bit rate query message may be sent from the remote UE and forwarded to the gNB via the new UL MAC CE via the relay UE (step 121). After adding the information related to the remote UE ID, the relay UE may forward the new UL MAC CE of the remote UE to the gNB (step 122). Similarly, in the downlink, the recommended bit rate DL MAC CE for the remote UE may be transmitted from the gNB to the relay UE together with the ID of the remote UE (step 131), and may then be forwarded by the relay UE to the remote UE. end UE (step 132).

Figure 2 is a simplified block diagram 200 of wireless devices 201 and 211 in accordance with novel aspects. For wireless device 201 (such as a relay UE), antennas 207 and 208 can transmit and receive radio signals. The radio frequency (Radio Frequency, RF) transceiver module 206 can be coupled with the antenna, receives the RF signal from the antenna, converts it into a base frequency signal and sends it to the processor 203 . The RF transceiver 206 can also convert the baseband signal received from the processor into an RF signal and send it to the antennas 207 and 208 . The processor 203 processes the received baseband signal and calls different functional modules and circuits to perform features in the wireless device 201 . Storage medium 202 may store program instructions and data 210 to control the operation of device 201.

Similarly, for wireless device 211 (such as a remote UE), antennas 217 and 218 can transmit and receive RF signals. The RF transceiver module 216 can be coupled to the antenna, receive the RF signal from the antenna, convert it into a baseband signal and send it to the processor 213 . The RF transceiver 216 may also convert the baseband signal received from the processor into an RF signal and send it to the antennas 217 and 218 . The processor 213 processes the received baseband signal and calls different functional modules and circuits to perform features in the wireless device 211 . Storage medium 212 may store program instructions and data 220 to control the operation of device 211.

Wireless devices 201 and 211 may also include a number of functional modules and circuits that may be implemented and configured to perform embodiments of the invention. In the example of Figure 2, the wireless device 201 may be a relay UE and may include a protocol stack 222, resource management circuitry 205 for allocating and scheduling sidelink resources, and connection processing circuitry for establishing and managing connections. 204. A relay processing controller 209 for relaying all or part of the control signaling and/or data services of the remote UE and a control and configuration circuit 221 for providing control and configuration information. The wireless device 211 may be a remote UE, including a protocol stack 232, relay discovery circuitry 214 for discovering relay UEs, connection processing circuitry 219 for establishing and managing connections, and configuration and control circuitry 231. Different functional modules and circuits can be implemented and configured through software, firmware, hardware and any combination thereof. The above functional modules and circuits, when executed by the processors 203 and 213 (for example, by executing the program codes 210 and 220), allow the relay UE 201 and the remote UE 211 to perform embodiments of the present invention accordingly.

In the case of L2-based SL relaying, relaying may be performed above the RLC sublayer via the relaying UE for control plane CP and user plane UP between the remote UE and the network. Uu SDAP/PDCP and RRC can be terminated between the remote UE and the gNB, while RLC, MAC and PHY can be terminated on each link (i.e. the link between the remote UE and the UE to the network relay UE and the UE to the network relay UE). terminated in the network relay link between UE and gNB). Uu supports the adaptation layer on the RLC layer for bearer mapping, and the adaptation layer can also be located on PC5 for bearer mapping on the sidelink. The adaptation layer between the relay UE and the gNB can distinguish the bearers (SRB, DRB) of a specific remote UE. Within a Uu DRB, different remote UEs and different bearers of the remote UE may be indicated by additional information contained in the adaptation layer header. In one example, the remote UE may transmit the recommended bit rate query MAC CE to the base station through processing by the relay UE. In another example, the remote UE may receive the recommended bit rate MAC CE from the base station through processing by the relay UE.

Figure 3 may illustrate an embodiment of forwarding recommended bitrate queries and recommended bitrate messages via RLC SDUs in accordance with novel aspects. In L2 relay, the base station can know each remote UE connected to the base station through the relay UE. Recommended bit rate queries designed to enhance MMTEL voice and video QoS can be used for end-to-end applications. Therefore, in order to ensure good end-to-end QoS, it is better for the gNB to clearly know the bit rate expected by each remote UE. In order to transmit the recommended bit rate query, the remote UE may send the desired bit rate to the base station through the relay UE.

In the embodiment of Figure 3, the recommended bit rate query message may be carried by control signaling, for example, by RLC SDU on the Uplink Dedicated Control Channel (UL-DCCH). For example, the information of the recommended bit rate query can be included in the existing RRC signaling, such as the sidelink UE information (Sidelink UEInformation) message, or the UE assistance information (UEAssistanceInformation) message or the new RRC message. The above-mentioned RRC signaling may be included in the RLC SDU and transmitted from the remote UE 303 (step 311) to the base station 301 through forwarding by the relay UE 302 (step 312). In this embodiment, the recommended bit rate query message is transmitted through dedicated signaling (ie, in the same manner as the remote UE sends UL data to the base station through the L2 SL relay).

Similarly, the base station may send a recommended bit rate to the remote UE to suggest an appropriate bit rate. In the L2 relay, since the gNB knows the existence of each remote UE, the recommended bit rate information from the gNB can be received by the remote UE. In one embodiment, as shown in Figure 3, the recommended bit rate information can be carried by control signaling, for example, it can be carried via RLC SDU on the DL-DCCH, and then the relay UE can forward it through the sidelink to the remote UE. For example, the recommended bit rate information may be included in existing RRC signaling, such as included in the RRC reconfiguration (RRCReconfiguration) message, and the above-mentioned RRC signaling may be included in the RLC SDU and passed from gNB 301 (step 321) The relay UE 302's forwarding (step 322) is transmitted to the remote UE 303. In this embodiment, the recommended bit rate is conveyed through dedicated signaling (ie, in the same manner as the base station sends DL data to the remote UE through the L2 SL relay).

Figure 4 may illustrate an embodiment of forwarding recommended bit rate queries via a UL MAC CE in accordance with novel aspects. If the desired bit rate is carried by the sidelink MAC CE, there are different ways to convey it from the remote UE 404 to the relay UE 403 (step 411). In one embodiment, the sidelink MAC CE used for the recommended bit rate query can be multiplexed into the SL MAC PDU according to traditional LCP and multiplexing procedures, similar to other sidelink MAC CEs. In one embodiment, the sidelink MAC CE used for recommended bit rate query can be considered as a typical SL RLC SDU profile. It can also be said that a MAC subPDU (subPDU) can be formed by adding an adaptation layer header, optionally adding an SL RLC header, and adding a MAC subheader (subheader), in which the logical channel identifier (LCID) field and/or the LCID value indicated in the eLCID field may inform the receiver that this MAC sub-PDU is used to carry the recommended bit rate query. The MAC sub-PDU containing the recommended bit rate query may then be forwarded from the remote UE 404 to the gNB 401 through the relay UE 403 and the relay UE 402.

After the relay UE receives the Recommended Bit Rate query, there are several ways to handle the query. In one embodiment, if the recommended bit rate query is carried in a format without an associated RLC header or adaptation layer header SL MAC CE, the relay UE may treat the SL MAC CE as an RLC SDU. This means that the relay UE can add the adaptation layer header and the RLC header before the SL MAC CE payload to form an RLC PDU, which can then be transmitted to the gNB by applying the traditional Uu LCP process. When the RLC PDU is multiplexed into a UL MAC PDU, the MAC subheader associated with the RLC PDU of the Recommended Bit Rate Query may include the UL LCID corresponding to the "Recommended Bit Rate Query MAC CE from the Remote UE" value. For multi-hop scenarios, the relay UE 403 can package the SL MAC CE into an SL RLC PDU, which can then be transmitted to the upstream relay UE by applying the traditional sidelink LCP process. 402. Similarly, the MAC sub-header of the SL RLC SDU may have an LCID to identify the contents of the RLC SDU as a Recommended Bit Rate Query MAC CE. In one example, the added adaptation layer header may include the ID of the remote UE that initiated the query.

In one embodiment, if the recommended bit rate query is carried in the format of SL MAC CE with associated RLC header or adaptation layer header, the relay UE may update the RLC header and adaptation layer header and then update the The RLC PDU is forwarded to the next hop (i.e. gNB or upstream relay UE). If the relay UE 402 forwards the RLC PDU to the gNB 401 (step 413), the MAC sub-header of the RLC PDU may indicate the LCID value corresponding to the recommended bit rate query MAC CE from the remote UE. In contrast, if the relay UE 403 forwards the RLC PDU to the upstream relay UE 402 (step 412), the SL MAC sub-header of the RLC PDU may indicate the LCID value corresponding to the recommended bit rate query SL MAC CE.

Figure 5 may illustrate an embodiment of forwarding recommended bit rates via DL MAC CE in accordance with novel aspects. New MAC CE types can be defined to carry recommended bit rate information transmitted from the gNB to the remote UE. The MAC CE type may have its own downlink LCID value, which may be defined by the LCID field or both the LCID field and the e-LCID field in the MAC sub-header (step 511). In the case where the MAC subheader indicates the LCID value corresponding to the recommended bit rate MAC CE of the remote UE, the corresponding MAC CE payload may include information of the remote UE, such as the ID of the remote UE.

In one example, in order to send the recommended bit rate for the remote UE, the gNB can put the information of the target remote UE (such as the ID of the target remote UE) into the adaptation layer header, and the other information mentioned above can include in the payload of MAC CE. For example, the gNB can treat the MAC CE payload as an RLC SDU, so it can add an adaptation layer header, an optional RLC header, and a MAC sub-header to it in sequence to form a MAC sub-PDU. After the relay UE receives the DL MAC PDU containing the MAC sub-PDU, the relay UE can learn that the MAC sub-PDU carries the LCID value for the remote end by checking the LCID value indicated in the LCID and/or eLCID field in the MAC sub-header. Recommended bit rate MAC CE for UE. The relay UE may then update the RLC header (if present and required) and the adaptation layer header (if required) and forward the SL RLC SDU to the remote UE (step 513) or the downstream relay UE (step 512) . When SL RLC SDUs are multiplexed into SL MAC PDUs, the SL MAC sub-header associated with the SL RLC SDU may include an LCID value corresponding to the recommended bit rate MAC CE on the sidelink. Note that similar to the Recommended Bit Rate Query MAC CE on the sidelink, the Recommended Bit Rate MAC CE on the sidelink can have a unique LCID value.

The relay UE can forward the recommended bit rate MAC CE to the remote UE in two ways. In one embodiment, the MAC CE payload may be formed into an SL MAC sub-PDU together with the adaptation layer header, the optional RLC header and the MAC sub-header, and be sent by the relay UE to the remote UE. The remote UE can learn from the LCID of the MAC sub-header of the MAC sub-PDU that the MAC sub-PDU is the recommended bit rate MAC CE, and remove the RLC header and adaptation layer header to read the MAC CE payload. In one embodiment, only the MAC CE payload and the MAC sub-header may form the MAC sub-PDU. When receiving the MAC sub-PDU, the remote UE can learn from the LCID of the MAC sub-header of the MAC sub-PDU that the MAC sub-PDU is the recommended bit rate MAC CE.

Figure 6 may illustrate an embodiment of SL MAC CE forwarding in UE-to-UE relaying in accordance with novel aspects. The architecture in which the network and the remote UE exchange UL MAC CE or DL MAC CE through the relay UE can also be applied to the UE-to-UE relay scenario. For UE-to-UE relay, the SL MAC CE can be forwarded through the relay UE instead of forwarding the UL or DL MAC CE. The forwarding method of SL MAC CE is similar to the UL and DL MAC CE in the UE to network relay. An adaptation layer header may be added to the SL MAC CE (e.g. for routing purposes) to form the SL MAC sub-PDU. Furthermore, an indicator may be used to indicate that this SL MAC sub-PDU includes (a certain type of) SL MAC CE, e.g. a specific sidelink LCID value may be applied in the MAC sub-header of the SL MAC sub-PDU.

For SL MAC CE forwarding, since the source and destination of SL MAC CE are both UEs, the adaptation layer header can contain both the source UE ID and the target UE ID, so that the target UE can know which UE initiated the SL MAC through the source UE ID. CE. In the example of Figure 6, the SL MAC CE may be encapsulated into a SL MAC sub-PDU, which may be sent from the source UE 601 (step 611) and routed according to the routing information of the adaptation layer header (including source ID and Target ID) is forwarded from the source UE to the target UE 604 via the relay UE 602 (step 612) and the relay UE 603 (step 613).

Figure 7 may illustrate an exemplary SL MAC PDU format with SL-SCH MAC subheader for MAC CE forwarding in accordance with novel aspects. The SL MAC PDU may include an SL-SCH MAC sub-header, several MAC sub-PDUs, and padding. Each MAC sub-PDU can carry data or MAC CE. The MAC sub-PDU for information may include a MAC sub-header and a MAC SDU. The MAC subheader format used for data may have a field "L" to indicate the size of the MAC SDU (number of bytes). The MAC sub-PDU for MAC CE may include the MAC sub-header and the MAC CE. Because all currently supported SL MAC CEs have a fixed size, the MAC subheader format used for MAC CEs can have no field "L".

The SL-SCH MAC sub-header may include an SRC field and a DST field to indicate who sends the SL MAC PDU (SRC) and who should receive the SL MAC PDU (DST). For example, if a SL MAC PDU is sent from the remote UE to relay UE2, relay UE1, and then to gNB, then when the remote UE sends the SL MAC PDU through SL, the DST field is relay UE2, and when relay UE2 forwards the SL When MAC PDU is used, the SRC field is the relay UE2 and the DST field is the relay UE1.

The LCID for SL-LCH may be used to indicate the content of the payload in the SL MAC sub-PDU. For example, if the LCID value is less than 20, the payload may be a MAC SDU, and if the LCID value is equal to 62, the payload may be a MAC CE for SL channel state information (Channel State Information, CSI) reporting. In the current MAC specification, there are two tables that can define the LCID values of DL-LCH and UL-SCH. For example, the LCID of the recommended bit rate DL message may be 47, and the LCID of the recommended bit rate UL message may be 53. According to a novel aspect, two SL LCID values can be added to the LCID table for SL-SCH. First, the "SL Recommended Bit Rate Query MAC CE" with LCID 61 for UE to gNB (uplink direction) can be added as the counterpart of the "UL Recommended Bit Rate Query MAC CE". Secondly, the "SL Recommended Bit Rate" with LCID 60 for gNB to UE (downlink direction) can be added as the counterpart of the "DL Recommended Bit Rate MAC CE".

Figure 8 may illustrate an embodiment of UL MAC CE forwarding through UE to network SL relay in accordance with novel aspects. In step 811, the remote UE 804 may send the UL MAC CE to the relay UE 803. At step 812, relay UE 803 may forward the UL MAC CE to relay UE 802. At step 813, relay UE 802 may forward the UL MAC CE to gNB 801. In this example, when the relay UE forwards the remote UE's recommended bit rate query to the base station, the UL LCID contained in the MAC sub-header of the MAC CE from the remote UE's recommended bit rate query can be the same as the traditional recommended bit rate query. Bit rate query UL LCID of MAC CE is different. Otherwise, the gNB may assume that the Recommended Bit Rate query comes from the relay UE itself, and may fail to decode the contents of the MAC CE payload.

In order to distinguish the recommended bit rate query MAC CE of the relay UE and the remote UE, the recommended bit rate query MAC CE of the remote UE may have different SL LCIDs, for example, the SL LCID may be set to 61. In the present invention, since the UL MAC CE can be used only in the SL relay scenario, it can be called "relay-specific recommended bit rate query". When the relay UE 802 checks the SL MAC sub-header and finds that the SL LCID value is 61, the relay UE 802 can know that this MAC payload contains the MAC CE for "Recommended Bit Rate Query" and therefore in the UL transmission (from the relay 802 to gNB 801), the relay UE 802 can select the UL LCID value for the "Recommended Bit Rate Query", which is 53 as defined in the UL LCID table.

In the present invention, a method is proposed on how to transmit UL MAC CE (Recommended Bit Rate Query MAC CE) from the remote UE to the base station. One of the main ideas is that when forwarding a MAC CE, the MAC CE can add an adaptation layer header for routing. With the addition of the adaptation layer header, additional LCID is required. For example, in order to forward the UL MAC CE, a new relay-specific UL LCID is needed, so that when the base station receives the UL MAC CE, the base station can know that the UL MAC CE comes from the remote UE, and can learn about the location of the UL MAC CE. Adaptation layer header contained in MAC SDU.

In one embodiment, the relay UE may forward the SL MAC sub-PDU to the base station as a UL MAC sub-PDU by converting the SL LCID into the corresponding UL LCID for the recommended bit rate query message.

Figure 9 may illustrate an embodiment of DL MAC CE forwarding through UE to network SL relay in accordance with novel aspects. In step 911, gNB 901 may send a DL MAC CE to relay UE 902. In step 912, relay UE 902 may forward the DL MAC CE to relay UE 903. In step 913, the relay UE 903 may forward the DL MAC CE to the remote UE 904. In this example, when the base station sends the recommended bit rate MAC CE to the remote UE, the base station may not apply the existing LCID to the recommended bit rate MAC CE in the MAC subheader. Otherwise, the relay UE will think that the recommended bit rate MAC CE is for the relay UE itself, not for the remote UE.

To avoid ambiguity, the recommended bit rate MAC CE for the remote UE may be assigned a different SL LCID, for example, the SL LCID may be set to 60. In the present invention, since the DL MAC CE can be used only in SL relay scenarios, it can be called "relay-specific recommended bit rate". When the relay UE 902 checks the DL MAC sub-header and finds that the DL LCID value is 47, the relay UE 902 can know that this MAC payload contains the MAC CE for the "recommended bit rate" and therefore in the SL transmission (from the relay UE 902 to the relay UE 903), the relay UE 902 can select the SL LCID value for the "recommended bit rate", which is 60 as defined in the SL LCID table.

In the present invention, a method is proposed on how to transmit DL MAC CE (recommended bit rate MAC CE) from the base station to the remote UE. One of the main ideas is that when forwarding a MAC CE, the MAC CE can add an adaptation layer header for routing. With the addition of the adaptation layer header, additional LCID is required. For example, in order to forward the DL MAC CE, a new relay-specific DL LCID is required, so that when the relay UE receives the DL MAC sub-PDU, the relay UE can know the existence of the adaptation layer header, so that it can route correctly.

In one embodiment, the relay UE may forward the DL MAC sub-PDU as an SL MAC sub-PDU to the remote UE by converting the DL LCID into the corresponding SL LCID for the recommended bit rate message.

The above framework can also be used to carry other UL MAC CE or DL MAC CE. For example, it would be useful if the remote UE could send a UL BSR via forwarding of the relay UE to inform the gNB of the amount of uplink data it has available in the uplink buffer. Based on feedback from the remote UE, if the remote UE has a large amount of data to transmit, the base station can provide sufficient resources or higher priority along the path to forward the remote UE's services.

Figure 10 is a flowchart of a method for forwarding a recommended bit rate query message through a sidelink relay by a MAC CE in accordance with novel aspects. In step 1001, the relay UE may receive a recommended bit rate query message from the remote UE. This message may be carried by control signaling or by a SL MAC CE dedicated to the remote UE. In step 1002, when the control signaling carries the recommended bit rate query message, the relay UE may forward the message to the base station through layer 2 sidelink relay. In step 1003, when the recommended bit rate query message is carried by the SL MAC CE, the relay UE may forward the message to the base station. The SL MAC CE can have a unique SL LCID value that indicates the recommended bit rate query message.

Figure 11 is a flowchart of a method for forwarding recommended bit rate messages through sidelink relays by a MAC CE in accordance with novel aspects. In step 1101, the relay UE may receive the recommended bit rate message from the base station. This message may be carried by control signaling or by a DL MAC CE dedicated to the remote UE. In step 1102, when the recommended bit rate information is carried by the control signaling, the relay UE may forward the information to the remote UE through the layer 2 sidelink relay. In step 1103, when the recommended bit rate message is carried by the DL MAC CE, the relay UE may forward the message to the remote UE. The DL MAC CE may have a DL LCID value, which may indicate the recommended bit rate message.

Although the present invention is disclosed above in conjunction with specific embodiments for guidance purposes, the present invention is not limited thereto. Accordingly, various modifications, adjustments and combinations can be made to the various features of the above embodiments without departing from the scope of the claims of the present invention.

100:Mobile communication system 101:5GC 102, 301, 401, 501, 801, 901:gNB 103, 104, 105, 302, 303, 402~404, 502~504, 601~604, 802~804, 902~904:UE 121, 122, 131, 132, 311, 312, 321, 322, 411~413, 511~513, 611~613, 811~813, 911~913, 1001~1003, 1101~1103: Steps 200:Block diagram 201, 211: Wireless equipment 202, 212:Storage media 203, 213: Processor 207, 208, 217, 218: Antenna 204, 219: Connection processing circuit 205: Resource management circuit 206, 216:Transceiver 209:Relay processing controller 210, 220: Program instructions 214:Relay discovery circuit 221, 231: Control and configuration circuits 222, 232: Protocol stacking

Figure 1 may illustrate a wireless mobile communications system supporting uplink and downlink MAC CE forwarding through SL relays in accordance with novel aspects. Figure 2 is a simplified block diagram of a wireless transmitting device and a receiving device according to an embodiment of the present invention. Figure 3 illustrates an embodiment of forwarding a recommended bit rate query and a recommended bit rate message via an RLC Service Data Unit (SDU) according to novel aspects. Figure 4 may illustrate an embodiment of forwarding a recommended bit rate query message via a UL MAC CE in accordance with novel aspects. Figure 5 may illustrate an embodiment of forwarding recommended bit rate messages via DL MAC CE in accordance with novel aspects. Figure 6 may illustrate an embodiment of SL MAC CE forwarding in UE-to-UE relaying in accordance with novel aspects. Figure 7 illustrates an exemplary SL MAC Protocol Data Unit (PDU) format with a Sidelink Shared Channel (SL-SCH) MAC sub-header for MAC CE forwarding in accordance with novel aspects. . Figure 8 may illustrate an embodiment of UL MAC CE forwarding through UE to network SL relay in accordance with novel aspects. Figure 9 may illustrate an embodiment of DL MAC CE forwarding through UE to network SL relay in accordance with novel aspects. Figure 10 is a flowchart of a method for forwarding a recommended bit rate query message through a sidelink relay by a MAC CE in accordance with novel aspects. Figure 11 is a flowchart of a method for forwarding recommended bit rate messages through sidelink relays by a MAC CE in accordance with novel aspects.

1001~1003: steps

Claims (18)

A method for wireless communication, executed by a relay user equipment, the method includes: receiving a recommended bit rate query message from a remote user equipment, wherein the recommended bit rate query message is controlled by a control The signaling may be carried by the control unit of the side link media access control dedicated to the remote user equipment, and the control signaling is a radio resource control signaling; when it is carried by the control signaling When the recommended bit rate query message is sent, the recommended bit rate query message is forwarded to a base station through the layer 2 sidelink relay; and when the control unit of the sidelink media access control When carrying the recommended bit rate query message, the recommended bit rate query message is forwarded to the base station, wherein the control unit of the sidelink media access control has a unique sidelink Logical channel identification value, the sidelink logical channel identification value indicates the recommended bit rate query message. The method for wireless communication as claimed in claim 1, wherein the recommended bit rate query message is carried by the radio resource control signaling included in a radio link control service information unit. The method for wireless communication according to claim 1, wherein the control unit of the sidelink media access control forms a sidelink media storage having a sidelink media access control subheader. A control sub-protocol data unit is obtained, wherein the side-link medium access control sub-header includes the unique side-link logical channel identifier that is different from an existing logical channel identifier value. The method for wireless communication according to claim 3, wherein the control unit of the sidelink media access control does not have an associated radio link control header or an associated adaptation layer header. The method for wireless communication as described in claim 4, wherein the relay user equipment adds an adaptation layer header and an adaptation layer header before the control unit of the sidelink media access control. The radio link control layer header is used to form a radio link control service information unit for forwarding to the base station. The method for wireless communication according to claim 3, wherein the control unit of sidelink media access control has an associated adaptation layer header. The method for wireless communication according to claim 6, wherein the control unit of sidelink media access control also has an associated radio link control header. The method for wireless communication as described in claim 6 or 7, wherein the relay user equipment updates the associated adaptation layer header or updates the associated adaptation layer header and the radio Both the link control header and the sidelink media access control control unit are forwarded as a radio link control protocol data unit. The method for wireless communication as claimed in claim 3, wherein the relay user equipment converts the sidelink logical channel identifier into the corresponding uplink for the recommended bit rate query message. A logical channel identifier is used to forward the side link media access control sub-protocol data unit to the base station as an uplink media access control sub-protocol data unit. A method for wireless communication, performed by a relay user equipment, the method includes: receiving a recommended bit rate message from a base station, wherein the recommended bit rate message is carried by a control signaling or by A remote user equipment-specific downlink media access control control unit is carried, and the control signaling is a radio resource control signaling; when the recommended bit rate information is carried by the control signaling , forwarding the recommended bit rate message to the remote user equipment through the layer 2 sidelink relay; and when the recommended bit rate message is controlled by the control unit of the downlink media access control When carrying, the recommended bit rate message is forwarded to the remote user equipment, wherein the control unit of the downlink media access control has a downlink logical channel identification value, and the downlink logical The channel identification value indicates the recommended bit rate message. The method for wireless communication as claimed in claim 10, wherein the recommended bit rate information is carried by the radio resource control signaling included in a radio link control service information unit. The method for wireless communication according to claim 10, wherein the recommended bit rate information is included in a payload of the control unit of the downlink media access control, wherein the downlink The control element of media access control has a new control element type of media access control and a downlink logical channel identification in the downlink media access control sub-header. The method for wireless communication as claimed in claim 10, wherein the recommended bit rate message is included in the payload of the control element of the downlink media access control, wherein an adaptation layer header is added and a media access control sub-header to form a downlink media access control sub-protocol data unit. The method for wireless communication according to claim 13, wherein the control element payload of the downlink media access control, the adaptation layer header and the media access control sub-header form a side row The link media access control sub-protocol data unit is forwarded by the relay user equipment to the remote user equipment. The method for wireless communication as described in claim 13, wherein the control element payload of the downlink media access control and the media access control sub-header form a side downlink media access control The sub-protocol data unit is forwarded by the relay user equipment to the remote user equipment. The method for wireless communication as claimed in claim 13, wherein the relay user equipment converts the downlink logical channel identifier into a corresponding sidelink for the recommended bit rate message. The logical channel identifier forwards the downlink MAC sub-protocol data unit as a side downlink MAC sub-protocol data unit to the remote user equipment. The method for wireless communication as claimed in claim 16, wherein the sidelink logical channel is indicated in a MAC sub-header of the sidelink MAC sub-protocol data unit The identification value is specific to the recommended bit rate of the remote UE and is different from the existing sidelink logical channel identification value. A relay user equipment for wireless communication includes: a receiver that receives a recommended bit rate query message from a remote user equipment, wherein the recommended bit rate query message is sent by the remote user equipment carried by a device-specific sidelink media access control control unit, wherein the receiver receives a recommended bit rate message from a base station, wherein the recommended bit rate message is provided by the remote user A device-specific downlink media access control control unit is carried; and a relay processing circuit forwards the recommended bit rate query message to the base station, wherein the sidelink media access control The control unit has a unique sidelink logical channel identification value, the sidelink logical channel identification value indicates the recommended bit rate query message, wherein the relay processing circuit converts the recommended bit rate The rate message is forwarded to the remote user equipment, wherein the control unit of the downlink media access control has a downlink logical channel identification value, and the downlink logical channel identification value indicates the recommended bit rate message.

Images