Small data transmission method, device and system in direct link relay scene

Abstract

The invention provides a small data transmission method, device and system in a straight-through link relay scene, and relates to the field of wireless communication and terminals. The method comprises: a UE receiving small data transmission configuration information based on an SL relay sent by a network side, the small data transmission configuration information based on the SL relay being used for enabling the UE to execute small data transmission based on the SL relay in an inactive state when the UE is in the inactive state and a small data transmission condition is satisfied. As the terminal does not need to enter the connection state when executing the small data transmission based on the SL relay, the energy consumption and unnecessary signaling overhead of the terminal are saved.

Description

Technical Field

[0001] The present disclosure relates to the field of wireless communications and terminals, and in particular to a small data transmission method, device and system in a direct link relay scenario. Background Art

[0002] NR (New Radio) SL (Sidelink) technology mainly implements V2X (vehicle to everything) related road safety services. On this basis, in order to further expand the coverage of the network and the direct link and improve power efficiency, a relay technology based on the NR direct link (NR sidelink Relay) is proposed, and U2N Relay (UE-to-Network Relay) technology is introduced. The remote UE (User Equipment) can communicate with the base station through the relay UE.

[0003] U2N relay technology can help operators expand network coverage and fill coverage gaps, and has broad application prospects; however, from the perspective of terminals, SL relay technology will significantly increase the energy consumption of relay UEs, thereby reducing the enthusiasm of UEs to serve as relay nodes, which is one of the reasons for the slow commercialization of SL relay technology. In order to promote the implementation and commercialization of SL relay technology, it is necessary to solve the energy-saving problem in SL relay scenarios.

[0004] In order to save terminal energy consumption, the NR system introduces the RRC_INACTIVE (Radio Resource Control_INACTIVE) state. For scenarios where data is not frequently transmitted, such as periodic and / or non-periodic, the network side can keep the terminal in the RRC_INACTIVE state, thereby saving terminal energy consumption while shortening the original delay from the RRC idle state to the RRC connected state. Prior to Rel-16, the RRC_INACTIVE state did not support data transmission. Therefore, the UE must return to the RRC connected state before any uplink or downlink data transmission can be performed. Even if the data packet is small and the data transmission frequency is low, each data transmission will establish a connection and then release it to the INACTIVE state, which will result in unnecessary power consumption and signaling overhead.

[0005] In order to further reduce terminal energy consumption and save signaling overhead, 3GPP introduced small data transmission technology in R17, allowing UE in RRC inactive state to perform signaling or data transmission of small data volume without triggering the UE in RRC inactive state to enter RRC connected state. Small data transmission in RRC inactive state can be sent through random access process or through dedicated signaling, such as RRCRelease (radio resource control release) pre-configured configuration authorization resources.

[0006] In the relevant U2N relay technology, both the relay UE and the remote UE must be in the RRC connected state to perform unicast data transmission and reception. Remote UEs such as smart watches and industrial sensors access the network through the relay UE. When the remote UE has small data to send, for example, when the remote needs to send WeChat real-time information, health monitoring information, periodic positioning information, etc., the remote UE and relay UE in the RRC inactive state must enter the RRC connected state to send unicast data. In the U2N relay scenario, neither the remote UE nor the relay UE can use the RRC inactive state small data transmission mechanism introduced in R17 to transmit and receive unicast data, which will greatly increase the energy consumption of remote users and relay users. At the same time, frequent small data transmission will repeatedly trigger the RRC connection establishment process, which will also cause unnecessary signaling overhead. Summary of the invention

[0007] A technical problem to be solved by the present disclosure is to provide a small data transmission method, device and system in a direct link relay scenario, which can reduce the signaling overhead of the user equipment and reduce the energy consumption of the user equipment.

[0008] According to one aspect of the present disclosure, a small data transmission method in a direct link relay scenario is proposed, including: a user equipment UE receives small data transmission configuration information based on a direct link SL relay sent by a network side, wherein the small data transmission configuration information based on the SL relay is used to enable the UE to perform inactive state small data transmission based on the SL relay when it is in an inactive state and meets a small data transmission condition.

[0009] In some embodiments, the UE receives the SL relay-based small data transmission configuration information sent by the network side, including: the UE receives the first message and the second message including the SL relay-based small data transmission configuration information sent by the network side, wherein the first message includes an indication of whether the current cell supports the SL relay-based small data transmission function and at least one of the SL relay-based small data transmission public configuration information; and the second message includes indication information that the UE enters an inactive state, and the UE's SL relay-based small data transmission dedicated configuration information.

[0010] In some embodiments, the public configuration information of small data transmission based on SL relay includes at least one of the following: a data volume threshold value, used to instruct the UE to judge whether the amount of data to be transmitted meets the data volume condition for executing the inactive state based on SL relay small data transmission; a signal quality threshold value, used to instruct the UE to judge whether the signal quality of the direct communication PC5 interface meets the signal quality condition for executing the inactive state based on SL relay small data transmission; and a small data transmission failure timer duration, used to instruct the UE to judge the timer duration value of the inactive state based on SL relay small data transmission.

[0011] In some embodiments, the small data transmission dedicated configuration information includes an indication of turning on or releasing the small data transmission function based on SL relay, wherein, in the case of indicating turning on the small data transmission function based on SL relay, the small data transmission dedicated configuration information also includes at least one of the following: for a UE acting as a relay node, including a list of small data transmission configuration information based on SL relay of one or more remote nodes associated with the relay node, to indicate that the relay node is allowed to perform inactive small data transmission for the associated one or more remote nodes through the user equipment to the network U2N relay; for a UE acting as a remote node, including at least one configuration information for small data transmission in an SL relay scenario; for a UE with relay capability, indicating whether it is possible to perform SL relay-based small data transmission for other remote nodes that are not in one or more remote nodes associated with the UE with relay capability; information related to the special configuration authorization of small data transmission based on SL relay, used to indicate specific configuration authorization information used by the relay node when forwarding small data of a remote node in an inactive state; for a remote node that has access to the network through a relay node, indicating whether it is possible to select or reselect a new relay node in an inactive state for small data transmission based on SL relay.

[0012] In some embodiments, the small data transmission configuration information list based on SL relay includes: identification information of the remote node, a list of data radio bearers of the remote node configured with small data transmission function, indication information of whether the signaling radio bearer SRB2 of the remote node is allowed to perform small data transmission, and at least one item in the direct link relay adaptation protocol SRAP layer configuration information list.

[0013] In some embodiments, at least one configuration information for small data transmission in an SL relay scenario includes: a list of data radio bearers configured with a small data transmission function at the remote node, indication information on whether the signaling radio bearer SRB2 of the remote node is allowed to perform small data transmission based on SL relay, and at least one item in the list of configuration information of the direct link relay adaptation protocol SRAP layer.

[0014] In some embodiments, the second message also includes whether the remote node and the relay node support small data transmission based on SL relay for each radio bearer in the direct link relay adaptation protocol SRAP configuration.

[0015] In some embodiments, the small data transmission configuration information list based on SL relay includes: identification information of the remote node, a list of data radio bearers of the remote node configured with small data transmission function, and at least one item of indication information of whether the signaling radio bearer SRB2 of the remote node is allowed to perform small data transmission.

[0016] In some embodiments, at least one configuration information for small data transmission in the SL relay scenario includes: a list of data radio bearers configured with small data transmission function at the remote node, and at least one item of indication information of whether the signaling radio bearer SRB2 of the remote node is allowed to perform small data transmission based on SL relay.

[0017] In some embodiments, for a remote node that has access to a network through a relay node, the small data transmission dedicated configuration information also includes a candidate relay node list for assisting the remote node in selecting or reselecting a relay node in an inactive state.

[0018] In some embodiments, the indication of whether the current cell supports the small data transmission function based on SL relay includes at least one of the following: indicating that the current cell supports at least one of the remote node and the relay node to perform inactive small data transmission in the user equipment to network U2N relay scenario; by configuring public configuration information for small data transmission in the SL relay scenario, to indicate that the current cell supports the small data transmission function based on SL relay.

[0019] In some embodiments, the first message is a system message; and the second message is an RRC signaling message.

[0020] In some embodiments, the UE reports the UE's small data transmission capability based on SL relay to the network side; and the UE exchanges the UE's small data transmission capability based on SL relay with the opposite UE.

[0021] In some embodiments, the UE's small data transmission capability based on SL relay includes at least one of the following: when the UE acts as a remote node, whether it supports the small data transmission function in an inactive state when accessing the network through the user equipment to the network U2N relay; when the UE acts as a relay node, whether it supports the small data transmission function of forwarding remote nodes in an inactive state in the U2N relay scenario; whether the UE supports the use of a configuration authorization method to perform small data transmission in an inactive state based on the U2N relay scenario; whether the UE supports the use of a random access method to perform small data transmission in an inactive state based on the U2N relay scenario; whether the UE supports the use of a configuration authorization method or a random access method to perform small data transmission in an inactive state on the signaling radio bearer SRB2 in the U2N relay scenario.

[0022] In some embodiments, when the UE acts as a remote node, the capability parameters of whether it supports the small data transmission function in an inactive state when accessing the network through the U2N relay include: only supporting small data transmission triggered by the terminal, only supporting small data transmission terminated by the terminal, and one of the small data transmission triggered by the terminal and the small data transmission terminated by the terminal at the same time; and when the UE acts as a relay node, the capability parameters of whether it supports the small data transmission function of forwarding the remote node in an inactive state in the U2N relay scenario include: only supporting small data transmission triggered by the terminal, only supporting small data transmission terminated by the terminal, and one of the small data transmission triggered by the terminal and the small data transmission terminated by the terminal at the same time.

[0023] In some embodiments, when the UE has not established a direct communication PC5 interface connection with the opposite UE, after the PC5 connection is established, the UE's SL relay-based small data transmission capability is interacted with the opposite UE.

[0024] According to another aspect of the present disclosure, a small data transmission method in a direct link relay scenario is also proposed, including: sending small data transmission configuration information based on a direct link SL relay to a user equipment UE, wherein the small data transmission configuration information based on the SL relay is used to enable the UE to perform inactive SL relay-based small data transmission when it is in an inactive state and meets small data transmission conditions.

[0025] In some embodiments, sending SL relay-based small data transmission configuration information to the UE includes: sending a first message and a second message including the SL relay-based small data transmission configuration information to the UE, wherein the first message includes an indication of whether the current cell supports the SL relay-based small data transmission function and at least one of the SL relay-based small data transmission public configuration information; and the second message includes indication information that the UE enters an inactive state, and the UE's SL relay-based small data transmission dedicated configuration information.

[0026] In some embodiments, the public configuration information of small data transmission based on SL relay includes at least one of the following: a data volume threshold value, used to instruct the UE to judge whether the amount of data to be transmitted meets the data volume condition for executing the inactive state based on SL relay; a signal quality threshold value, used to instruct the UE to judge whether the signal quality of the PC5 interface meets the signal quality condition for executing the inactive state based on SL relay; and a small data transmission failure timer length, used to instruct the UE to judge the timer length value of the inactive state based on SL relay small data transmission.

[0027] In some embodiments, the small data transmission dedicated configuration information includes an indication of turning on or releasing the small data transmission function based on SL relay, wherein, in the case of indicating turning on the small data transmission function based on SL relay, the small data transmission dedicated configuration information also includes at least one of the following: for a UE acting as a relay node, including a list of small data transmission configuration information based on SL relay of one or more remote nodes associated with the relay node, to indicate that the relay node is allowed to perform inactive small data transmission for the associated one or more remote nodes through the user equipment to the network U2N relay; for a UE acting as a remote node, including at least one configuration information for small data transmission in an SL relay scenario; for a UE with relay capability, indicating whether it is possible to perform SL relay-based small data transmission for other remote nodes that are not in one or more remote nodes associated with the UE with relay capability; information related to the authorization of the dedicated configuration of small data transmission based on SL relay; for a remote node capable of accessing the network through a relay node, indicating whether it is possible to select or reselect a new relay node in an inactive state for SL relay-based small data transmission.

[0028] In some embodiments, the small data transmission capability based on SL relay reported by the UE is received.

[0029] In some embodiments, according to the UE's SL relay-based small data transmission capability and service requirements, it is determined whether it is necessary to enable the SL relay-based small data transmission function for the UE.

[0030] In some embodiments, the UE's small data transmission capability based on SL relay includes at least one of the following: when the UE acts as a remote node, whether it supports the small data transmission function in an inactive state when accessing the network through the user equipment to the network U2N relay; when the UE acts as a relay node, whether it supports the small data transmission function of forwarding remote nodes in an inactive state in the U2N relay scenario; whether the UE supports the use of a configuration authorization method to perform small data transmission in an inactive state based on the U2N relay scenario; whether the UE supports the use of a random access method to perform small data transmission in an inactive state based on the U2N relay scenario; whether the UE supports the use of a configuration authorization method or a random access method to perform small data transmission in an inactive state on the signaling radio bearer SRB2 in the U2N relay scenario.

[0031] According to another aspect of the present disclosure, a user equipment is also proposed, including: a first transceiver module, configured to receive small data transmission configuration information based on a direct link SL relay sent by a network side, wherein the small data transmission configuration information based on the SL relay is used to enable the UE to perform small data transmission based on the SL relay in an inactive state when it is in an inactive state and meets the small data transmission conditions.

[0032] According to another aspect of the present disclosure, a user equipment is also proposed, including: a memory; and a processor coupled to the memory, wherein the processor is configured to execute the small data transmission method as described above based on instructions stored in the memory.

[0033] According to another aspect of the present disclosure, a base station is also proposed, including: a second transceiver module, configured to send small data transmission configuration information based on a direct link SL relay to a user equipment UE, wherein the small data transmission configuration information based on the SL relay is used to enable the UE to perform inactive SL relay-based small data transmission when it is in an inactive state and meets small data transmission conditions.

[0034] According to another aspect of the present disclosure, a base station is further proposed, including: a memory; and a processor coupled to the memory, wherein the processor is configured to execute the above-mentioned small data transmission method based on instructions stored in the memory.

[0035] According to another aspect of the present disclosure, a small data transmission system in a direct link relay scenario is also proposed, including: the above-mentioned user equipment, wherein the user equipment includes a remote user equipment and at least one relay user equipment; and at least one of the above-mentioned base stations.

[0036] According to another aspect of the present disclosure, a non-transitory computer-readable storage medium is also provided, on which computer program instructions are stored, and when the instructions are executed by a processor, the small data transmission method as described above is implemented.

[0037] In the disclosed embodiment, the network side sends SL relay-based small data transmission configuration information to the UE, so that the UE can perform inactive SL relay-based small data transmission when it is in an inactive state and meets the small data transmission conditions. Since the UE does not need to enter the connected state to perform unicast data transmission and reception, terminal energy consumption and unnecessary signaling overhead are saved.

[0038] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0040] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0041] Figure 1 It is a flowchart of some embodiments of the small data transmission method in the direct link relay scenario disclosed in the present invention;

[0042] Figure 2 It is a flowchart diagram of other embodiments of the small data transmission method in the direct link relay scenario disclosed in the present invention;

[0043] Figure 3 It is a flowchart diagram of other embodiments of the small data transmission method in the direct link relay scenario disclosed in the present invention;

[0044] Figure 4 It is a flowchart diagram of other embodiments of the small data transmission method in the direct link relay scenario disclosed in the present invention;

[0045] Figure 5 It is a flowchart diagram of other embodiments of the small data transmission method in the direct link relay scenario disclosed in the present invention;

[0046] Figure 6 It is a flowchart diagram of other embodiments of the small data transmission method in the direct link relay scenario disclosed in the present invention;

[0047] Figure 7 It is a flowchart diagram of other embodiments of the small data transmission method in the direct link relay scenario disclosed in the present invention;

[0048] Figure 8 It is a schematic diagram of the structure of some embodiments of the user equipment disclosed in the present invention;

[0049] Fig. 9 It is a schematic diagram of the structure of some other embodiments of the user equipment disclosed in the present invention;

[0050] Fig.10 It is a schematic diagram of the structure of some other embodiments of the user equipment disclosed in the present invention;

[0051] Fig.11 It is a schematic diagram of the structure of some embodiments of the base station disclosed in the present invention;

[0052] Fig.12 are structural schematic diagrams of other embodiments of the base station disclosed in the present invention; and

[0053] Fig.13 It is a schematic diagram of the structure of other embodiments of the base station disclosed in the present invention. DETAILED DESCRIPTION

[0054] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure unless otherwise specifically stated.

[0055] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0056] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0057] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0058] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0059] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0060] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0061] The UE disclosed in the present invention, also known as a terminal or terminal device, is a device with wireless transceiver function, which can communicate with one or more CNs (core networks) via access network devices in (R)AN ((radio)access network). It can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; it can also be deployed on the water surface, such as on a ship; it can also be deployed in the air, for example, on an airplane, a balloon or a satellite. UE can be a smart watch, an industrial sensor, a mobile phone, a tablet computer, a computer with wireless transceiver function, a VR (virtual reality) terminal device, an AR (Augmented Reality) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The embodiments of the present disclosure do not limit the UE.

[0062] In this document, the term base station has the full breadth of its usual meaning and includes at least a wireless communication station that is part of a wireless communication system or radio system to facilitate communication. A base station is, for example, a macro base station, a micro base station (also called a small station), a home base station (e.g., home evolved NodeB, or home Node B, HNB), etc.

[0063] The small data transmission disclosed in the present invention includes user plane small data transmission or control plane signaling transmission.

[0064] Figure 1 The present invention is a flowchart of some embodiments of the small data transmission method in the direct link relay scenario of the present invention.

[0065] In step 110, the UE receives SL relay-based small data transmission configuration information sent by the network side. The SL relay-based small data transmission configuration information is used to enable the UE to perform inactive SL relay-based small data transmission when it is in an inactive state and meets the small data transmission condition.

[0066] The small data transmission configuration information based on SL relay includes a first message and a second message.

[0067] In some embodiments, the first message includes: an indication of whether the current cell supports a small data transmission function based on SL relay and at least one of public configuration information of small data transmission based on SL relay. The first message is, for example, a system message.

[0068] When the SL relay-based small data transmission configuration information only includes an indication of whether the current cell supports the SL relay-based small data transmission function, that is, when the network side only indicates support for the SL relay-based small data transmission function but does not configure the small data transmission-related public configuration parameters for the SL relay scenario, the UE uses the existing small data transmission public configuration parameters, for example, the small data transmission common configuration system information block (SDT-ConfigCommonSIB-r17), to perform SL relay-based small data transmission.

[0069] In some embodiments, the current cell is a wireless area controlled by a base station that sends the SL relay-based small data transmission configuration information.

[0070] In some other embodiments, the second message includes: indication information that the UE enters an inactive state, and dedicated configuration information for small data transmission based on SL relay of the UE. The second message is an RRC signaling message.

[0071] In step 120, according to the SL relay-based small data transmission configuration information, the UE performs inactive SL relay-based small data transmission when it is in an inactive state and meets the small data transmission condition.

[0072] In the above embodiment, the network side sends the SL relay-based small data transmission configuration information to the UE, so that the UE can perform the SL relay-based small data transmission in the inactive state when it is in the inactive state and meets the small data transmission conditions, thereby improving the reliability of small data transmission in the inactive state in the SL relay scenario. Since the UE does not need to enter the connected state to perform unicast data transmission and reception, it saves terminal energy consumption and unnecessary signaling overhead.

[0073] Figure 2 The present invention is a flowchart diagram of other embodiments of the small data transmission method in the direct link relay scenario of the present invention.

[0074] In step 210, the UE receives at least one of an indication of whether the current cell supports a small data transmission function based on SL relay and public configuration information of small data transmission based on SL relay, which is sent by the base station.

[0075] The UE can act as both a remote node and a relay node. In some embodiments, an explicit indication is added to the system message on the network side to indicate support for remote UE and / or relay UE to perform inactive small data transmission in the U2N relay scenario. Alternatively, by configuring relevant public configuration parameters for small data transmission in the SL relay scenario, an implicit indication is given that the network side supports this function.

[0076] In some embodiments, the small data transmission public configuration information based on SL relay includes: at least one of a data volume threshold value, a signal quality threshold value, and a small data transmission failure timer duration.

[0077] The data volume threshold is used to instruct the UE to determine whether the amount of data to be transmitted meets the data volume condition for performing inactive SL relay-based small data transmission. For example, when the amount of data to be transmitted by the UE is greater than the data volume threshold, inactive small data transmission in the U2N scenario cannot be performed.

[0078] The signal quality threshold is used to instruct the UE to determine whether the signal quality of the PC5 (direct communication) interface meets the signal quality conditions for performing small data transmission based on SL relay in an inactive state. For example, when the link quality between the remote UE and the relay UE is lower than the signal quality threshold, small data transmission in an inactive state cannot be performed in the U2N scenario. The signal quality is, for example, RSRP (Reference Signal Received Power).

[0079] The duration of the small data transmission failure timer is used to instruct the UE to determine the timer value for small data transmission based on the SL relay in the inactive state.

[0080] In step 220, the UE sends the SL relay-based small data transmission capability of the UE to the base station.

[0081] The SL relay-based small data transmission capability indication is used to indicate whether the UE supports the small data transmission function in the inactive state in the SL relay scenario.

[0082] In some embodiments, the SL relay-based small data transmission capability of the UE includes at least one of the following parameters 1-5.

[0083] Parameter 1 indicates whether the UE supports the inactive small data transmission function when accessing the network through the U2N relay when the UE acts as a remote UE. Parameter 1 includes supporting only MO-SDT (Mobile Originated Small Data Transmission), supporting only MT-SDT (Mobile Termination Small Data Transmission), or both MO-SDT and MT-SDT. When the UE acts as a remote UE, it supports MO-SDT, that is, when the UE acts as a remote UE, it supports uplink small data sending based on the SL relay. When the UE acts as a remote UE, it supports MT-SDT, that is, when the UE acts as a remote UE, it supports downlink small data reception based on the SL relay.

[0084] Parameter 2 indicates whether the UE supports the small data transmission function of forwarding remote UEs in an inactive state in the U2N relay scenario when the UE acts as a relay UE. Parameter 2 includes supporting only MO-SDT, only MT-SDT, or supporting both MO-SDT and MT-SDT. When the UE acts as a relay UE, it supports MO-SDT, that is, when the UE acts as a relay UE, it supports uplink small data transmission based on SL relay. When the UE acts as a relay UE, it supports MT-SDT, that is, when the UE acts as a relay UE, it supports downlink small data reception based on SL relay.

[0085] Parameter 3 indicates whether the UE supports the use of the configuration authorization method to perform small data transmission in an inactive state based on the U2N relay scenario.

[0086] Parameter 4 indicates whether the UE supports the use of random access to perform small data transmission in an inactive state in a U2N relay scenario.

[0087] Parameter 5 indicates whether the UE supports small data transmission of SRB (Signalling Radio Bearer) 2 in an inactive state using a configuration authorization method or a random access method based on a U2N relay scenario.

[0088] In step 230, the UE exchanges the SL relay-based small data transmission capability of the UE with the opposite UE.

[0089] In some embodiments, when the UE has not established a PC5 interface connection with the opposite UE, after the PC5 connection is established, the UE's SL relay-based small data transmission capability is exchanged with the opposite UE.

[0090] If the UE has established a PC5 interface connection with the opposite UE, the UE's small data transmission capability based on SL relay is directly interacted with the opposite UE.

[0091] In step 240, the UE receives the indication information that the UE enters the inactive state and the dedicated configuration information of the UE for small data transmission based on the SL relay, which are sent by the base station.

[0092] In some embodiments, the base station determines whether it is necessary to enable the SL relay-based small data transmission function for the UE based on the SL relay-based small data transmission capability and specific services reported by the UE, and indicates the SL relay-based small data transmission dedicated configuration information to the UE through RRC dedicated signaling.

[0093] For example, when the UE acts as a remote UE and supports the inactive small data transmission function when accessing the network through the U2N relay, when the UE acts as a remote UE, the base station indicates the dedicated configuration information of small data transmission based on the SL relay to the UE through RRC dedicated signaling.

[0094] For another example, when the UE acts as a relay UE, it supports the small data transmission function of forwarding remote UE in an inactive state in the U2N relay scenario. When the UE acts as a relay UE, the base station indicates the dedicated configuration information of small data transmission based on SL relay to the UE through RRC dedicated signaling.

[0095] In some embodiments, the small data transmission dedicated configuration information includes an indication of turning on or releasing the small data transmission function based on SL relay, wherein, when indicating turning on the small data transmission function based on SL relay, the small data transmission dedicated configuration information also includes at least one item of the following dedicated configuration information 1-5.

[0096] Dedicated configuration information 1 is for a UE acting as a relay node, and includes a list of SL relay-based small data transmission configuration information of one or more remote nodes associated with the relay node, to indicate that the relay node is allowed to perform inactive small data transmission for the associated one or more remote nodes through the user equipment to the network U2N relay. The one or more remote nodes associated with the relay node are remote nodes that have already entered the network through the relay node.

[0097] The SL relay-based small data transmission configuration information list includes: identification information of the remote node, a DRB (Data Radio Bearer) list of the remote node configured with a small data transmission function, indication information of whether the remote node's SRB2 is allowed to perform small data transmission, and at least one item in the SRAP (Sidelink Relay Adaptation Protocol) layer configuration information list.

[0098] The identification information of the remote node is ID (Identifier) ​​information, that is, the L2 local UEID (Layer 2local) ID of the remote node. The DRB list of the remote node configured with the small data transmission function contains one or more DRB IDs, which are used to indicate that the DRBs in the allowed list are allowed to perform non-activated small data transmission based on SL relay. The SRAP layer configuration information list is used to indicate the mapping relationship between one or more bearers and Uu RLC (Radio Link Control) channels and PC5 RLC channels. Each SRAP layer configuration information includes a bearer ID (DRB ID or SRB ID), the corresponding export Uu RLC channel ID, and the corresponding export PC5 RLC channel ID.

[0099] The dedicated configuration information 2 is for the UE as a remote node, and includes at least one configuration information for small data transmission in the SL relay scenario.

[0100] The at least one configuration information for small data transmission in the SL relay scenario includes: a DRB list of remote nodes configured with small data transmission function, indication information of whether SRB2 of the remote node is allowed to perform small data transmission based on SL relay, and at least one item in the SRAP layer configuration information list.

[0101] The DRB list for which the remote node is configured with the small data transmission function includes one or more DRB IDs, indicating that the remote node is allowed to perform inactive small data transmission based on SL relay for the DRBs in the list. The SRAP layer configuration information list is used to indicate the mapping relationship between one or more bearers and Uu RLC channels and PC5 RLC channels. Each SRAP layer configuration information includes a bearer ID (DRB ID or SRB ID), the corresponding egress Uu RLC channel ID, and the corresponding egress PC5 RLC channel ID.

[0102] The dedicated configuration information 3 indicates, for the UE with relay capability, whether it is possible to perform small data transmission based on SL relay for other remote nodes that are not in one or more remote nodes associated with the UE with relay capability.

[0103] For example, for a UE with U2N relay capability, it indicates whether it can perform small data transmission based on SL relay for a new remote node that has not yet accessed the network through the relay node.

[0104] The dedicated configuration information 4 is related information about the dedicated configuration authorization for small data transmission based on SL relay, and is used to indicate specific configuration authorization information used by the relay node when forwarding small data of a remote node in an inactive state.

[0105] If the network side does not indicate this information, the relay node uses the configuration authorization information for the relay node's own small data transmission configured by the network side to forward the small data of the remote UE, that is, uses the existing configuration authorization information for small data transmission (IE SDT-CG-Config-r17) to forward small data.

[0106] The dedicated configuration information 5 indicates, for a remote node that has access to the network through a relay node, whether it can select or reselect a new relay node in an inactive state to perform small data transmission based on SL relay.

[0107] In some embodiments, for a remote node that has access to a network through a relay node, the small data transmission dedicated configuration information also includes a candidate relay node list, which is used to assist the remote node in selecting or reselecting a relay node in an inactive state. The candidate relay node list contains at least candidate relay node ID information. When the remote UE receives an indication of permission, the remote UE can select or reselect a new relay node in an inactive state to perform small data transmission based on SL relay based on business needs. The selected or reselected relay node can be a relay node in the candidate relay list or a relay node outside the list.

[0108] In other embodiments, when the network side configures SRAP-related configurations for the remote UE and the relay UE through an RRC reconfiguration message, it also indicates whether to allow small data transmission based on SL relay for the corresponding bearer.

[0109] For example, when at least one of the remote nodes or relay nodes needs to enter an inactive state, the network side sends an RRCRelease message to the remote node and / or relay node respectively, instructing the corresponding UE to enter an inactive state, and indicating the dedicated configuration information for small data transmission based on SL relay. At this time, the dedicated configuration information for small data transmission based on SL relay does not include SRAP-related configuration information for the remote node and relay node, and other configuration information is the same as the previous configuration information.

[0110] That is, the SL relay-based small data transmission configuration information list includes: identification information of the remote node, a DRB list of the remote node configured with a small data transmission function, and at least one of indication information of whether the remote node's SRB2 is allowed to perform small data transmission.

[0111] The at least one configuration information for small data transmission in the SL relay scenario includes: a DRB list of the remote node configured with the small data transmission function, and at least one item of indication information of whether the SRB2 of the remote node is allowed to perform small data transmission based on SL relay.

[0112] In step 250, the UE enters an inactive state according to the indication information, and performs inactive SL relay-based small data transmission based on the small data transmission public configuration information and small data transmission dedicated configuration information of the SL relay if the small data transmission conditions are met.

[0113] In the above embodiment, for cells that support the small data transmission function based on SL relay, the network side broadcasts an indication of supporting this function and related public configuration information, and the UE interacts with the base station and the opposite UE to perform small data transmission capabilities based on SL relay. The auxiliary network side configures a dedicated configuration for small data transmission based on SL relay according to specific UE capabilities and service characteristics. The terminal can perform non-activated small data transmission based on SL relay according to the public configuration information and dedicated configuration information for small data transmission based on SL relay indicated by the network side, thereby reducing the UE's energy consumption and unnecessary signaling overhead.

[0114] Figure 3 The present invention is a flowchart diagram of other embodiments of the small data transmission method in the direct link relay scenario of the present invention.

[0115] In step 310, the base station sends small data transmission configuration information based on SL relay to the UE.

[0116] In some embodiments, the SL relay-based small data transmission configuration information includes a first message and a second message.

[0117] The first message includes at least one of an indication of whether the current cell supports a small data transmission function based on SL relay and public configuration information of small data transmission based on SL relay. The first message is, for example, a system message.

[0118] When the SL relay-based small data transmission configuration information only includes an indication of whether the current cell supports the SL relay-based small data transmission function, that is, when the network side only indicates support for the SL relay-based small data transmission function but does not configure the small data transmission-related public configuration parameters for the SL relay scenario, the UE uses the existing small data transmission public configuration parameters for SL relay-based small data transmission.

[0119] In some other embodiments, the second message includes: indication information that the UE enters an inactive state, and dedicated configuration information for small data transmission based on SL relay of the UE. The second message is an RRC signaling message.

[0120] In step 320, the UE performs inactive SL relay-based small data transmission according to the SL relay-based small data transmission configuration information when the UE is in an inactive state and meets the small data transmission condition.

[0121] In the above embodiment, the base station sends SL relay-based small data transmission configuration information to the UE, so that the UE can perform inactive SL relay-based small data transmission when it is in an inactive state and meets the small data transmission conditions. Since the UE does not need to enter the connected state to perform small data transmission, it can save terminal energy consumption and unnecessary signaling overhead.

[0122] Figure 4 The present invention is a flowchart diagram of other embodiments of the small data transmission method in the direct link relay scenario of the present invention.

[0123] In step 410, the base station sends to the UE at least one of an indication of whether the current cell supports a small data transmission function based on SL relay and public configuration information of small data transmission based on SL relay.

[0124] In some embodiments, an explicit indication is added to the system message on the network side to indicate support for remote UE and / or relay UE to perform inactive small data transmission in the U2N relay scenario. Alternatively, by configuring relevant public configuration parameters for small data transmission in the SL relay scenario, an implicit indication is given that the network side supports this function.

[0125] In some embodiments, the small data transmission public configuration information based on SL relay includes: at least one of a data volume threshold value, a signal quality threshold value, and a small data transmission failure timer duration.

[0126] The data volume threshold is used to instruct the UE to determine whether the amount of data to be transmitted meets the data volume condition for performing inactive SL relay-based small data transmission. For example, when the amount of data to be transmitted by the UE is greater than the data volume threshold, inactive small data transmission in the U2N scenario cannot be performed.

[0127] The signal quality threshold is used to instruct the UE to determine whether the signal quality of the PC5 interface meets the signal quality conditions for performing inactive SL relay-based small data transmission. For example, when the link quality between the remote UE and the relay UE is lower than the signal quality threshold, inactive small data transmission in the U2N scenario cannot be performed.

[0128] The duration of the small data transmission failure timer is used to instruct the UE to determine the timer value for small data transmission based on the SL relay in the inactive state.

[0129] In step 420, the base station receives the SL relay-based small data transmission capability sent by the UE.

[0130] In some embodiments, the SL relay-based small data transmission capability indication is used to indicate whether the UE supports the small data transmission function in an inactive state in a SL relay scenario.

[0131] In some embodiments, the SL relay-based small data transmission capability of the UE includes at least one of the following parameters 1-5.

[0132] Parameter 1 indicates whether the UE supports the inactive small data transmission function when accessing the network through the U2N relay when the UE is a remote UE. Parameter 1 includes supporting only MO-SDT, only MT-SDT, or both MO-SDT and MT-SDT. When the UE is a remote UE, it supports MO-SDT, that is, when the UE is a remote UE, it supports uplink small data transmission based on the SL relay. When the UE is a remote UE, it supports MT-SDT, that is, when the UE is a remote UE, it supports downlink small data reception based on the SL relay.

[0133] Parameter 2 indicates whether the UE supports the small data transmission function of forwarding remote UEs in an inactive state in the U2N relay scenario when the UE acts as a relay UE. Parameter 2 includes supporting only MO-SDT, only MT-SDT, or supporting both MO-SDT and MT-SDT. When the UE acts as a relay UE, it supports MO-SDT, that is, when the UE acts as a relay UE, it supports uplink small data transmission based on SL relay. When the UE acts as a relay UE, it supports MT-SDT, that is, when the UE acts as a relay UE, it supports downlink small data reception based on SL relay.

[0134] Parameter 3 indicates whether the UE supports the use of the configuration authorization method to perform small data transmission in an inactive state based on the U2N relay scenario.

[0135] Parameter 4 indicates whether the UE supports the use of random access to perform small data transmission in an inactive state in a U2N relay scenario.

[0136] Parameter 5 indicates whether the UE supports small data transmission of SRB2 in an inactive state using a configuration authorization method or a random access method in a U2N relay scenario.

[0137] In step 430, the base station generates indication information for the UE to enter an inactive state and dedicated configuration information for the UE's small data transmission based on the SL relay according to the UE's small data transmission capability based on the SL relay and service requirements.

[0138] In some embodiments, the base station determines whether it is necessary to enable the SL relay-based small data transmission function for the UE based on the SL relay-based small data transmission capability and specific services reported by the UE, and indicates the SL relay-based small data transmission dedicated configuration information to the UE through RRC dedicated signaling.

[0139] For example, the UE has a small data transmission capability based on SL relay, and the base station determines that the terminal has service requirements, and then sends an indication message of entering an inactive state to the terminal, and transmits related small data transmission dedicated configuration information to the UE.

[0140] In some embodiments, the small data transmission dedicated configuration information includes an indication of turning on or releasing the small data transmission function based on SL relay, wherein, when indicating turning on the small data transmission function based on SL relay, the small data transmission dedicated configuration information also includes at least one item of the following dedicated configuration information 1-5.

[0141] Dedicated configuration information 1 is for a UE acting as a relay node, and includes a list of SL relay-based small data transmission configuration information of one or more remote nodes associated with the relay node, to indicate that the relay node is allowed to perform inactive small data transmission for one or more associated remote nodes through the user equipment to the network U2N relay. The one or more remote nodes associated with the relay node are remote nodes that have accessed the network through the relay node.

[0142] The SL relay-based small data transmission configuration information list includes: identification information of the remote node, a DRB list of the remote node configured with a small data transmission function, indication information of whether the remote node's SRB2 is allowed to perform small data transmission, and at least one item in the SRAP layer configuration information list.

[0143] The identification information of the remote node is ID information, that is, the L2 ID of the remote node. The DRB list of the remote node configured with the small data transmission function contains one or more DRB IDs, which are used to indicate that the DRBs in the allowed list are allowed to perform non-activated small data transmission based on SL relay. The SRAP layer configuration information list is used to indicate the mapping relationship between one or more bearers and Uu RLC channels and PC5RLC channels. Each SRAP layer configuration information includes a bearer ID, a corresponding egress Uu RLC channel ID, and a corresponding egress PC5 RLC channel ID.

[0144] Dedicated configuration information 2 is for UE as a remote node, and includes at least one configuration information for small data transmission in the SL relay scenario. The at least one configuration information for small data transmission in the SL relay scenario includes: a DRB list of remote nodes configured with small data transmission function, indication information of whether SRB2 of the remote node is allowed to perform small data transmission based on SL relay, and at least one item in the SRAP layer configuration information list.

[0145] The DRB list for which the remote node is configured with the small data transmission function includes one or more DRB IDs, indicating that the remote node is allowed to perform inactive small data transmission based on SL relay for the DRBs in the list. The SRAP layer configuration information list is used to indicate the mapping relationship between one or more bearers and Uu RLC channels and PC5 RLC channels. Each SRAP layer configuration information includes a bearer ID (DRB ID or SRB ID), the corresponding egress Uu RLC channel ID, and the corresponding egress PC5 RLC channel ID.

[0146] The dedicated configuration information 3 indicates, for the UE with relay capability, whether it is possible to perform small data transmission based on SL relay for other remote nodes that are not in one or more remote nodes associated with the UE with relay capability.

[0147] For example, for a UE with U2N relay capability, it indicates whether it can perform small data transmission based on SL relay for a new remote node that has not yet accessed the network through the relay node.

[0148] The dedicated configuration information 4 is related information about the dedicated configuration authorization for small data transmission based on SL relay, and is used to indicate specific configuration authorization information used by the relay node when forwarding small data of a remote node in an inactive state.

[0149] If the network side does not indicate this information, the relay node uses the configuration authorization information for the relay node's own small data transmission configured by the network side to forward the small data of the remote UE, that is, uses the existing configuration authorization information for small data transmission (IE SDT-CG-Config-r17) to forward small data.

[0150] The dedicated configuration information 5 indicates, for a remote node that has access to the network through a relay node, whether it can select or reselect a new relay node in an inactive state to perform small data transmission based on SL relay.

[0151] In some embodiments, for a remote node that has access to a network through a relay node, the small data transmission dedicated configuration information also includes a candidate relay node list, which is used to assist the remote node in selecting or reselecting a relay node in an inactive state. The candidate relay node list contains at least candidate relay node ID information. When the remote UE receives an indication of permission, the remote UE can select or reselect a new relay node in an inactive state to perform small data transmission based on SL relay based on business needs. The selected or reselected relay node can be a relay node in the candidate relay list or a relay node outside the list.

[0152] In other embodiments, when the network side configures SRAP-related configurations for the remote UE and the relay UE through an RRC reconfiguration message, it also indicates whether to allow small data transmission based on SL relay for the corresponding bearer.

[0153] For example, when at least one of the remote nodes or relay nodes needs to enter an inactive state, the network side sends an RRCRelease message to the remote node and / or relay node respectively, instructing the corresponding UE to enter an inactive state, and indicating the dedicated configuration information for small data transmission based on SL relay. At this time, the dedicated configuration information for small data transmission based on SL relay does not include SRAP-related configuration information for the remote node and relay node, and other configuration information is the same as the previous configuration information.

[0154] That is, the SL relay-based small data transmission configuration information list includes: identification information of the remote node, a DRB list of the remote node configured with a small data transmission function, and at least one of indication information of whether the remote node's SRB2 is allowed to perform small data transmission.

[0155] The at least one configuration information for small data transmission in the SL relay scenario includes: a DRB list of the remote node configured with the small data transmission function, and at least one item of indication information of whether the SRB2 of the remote node is allowed to perform small data transmission based on SL relay.

[0156] In step 440, the base station sends indication information indicating that the UE has entered an inactive state and dedicated configuration information for small data transmission based on SL relay of the UE to the UE.

[0157] The UE enters the inactive state according to the instruction of the base station. When there is small data transmission, it performs the inactive small data transmission in the SL relay scenario according to the small data transmission related configuration information based on the SL relay indicated by the network side.

[0158] In the above embodiment, for cells that support the small data transmission function based on SL relay, the base station broadcasts an indication of supporting the function and related public configuration information. The base station receives the small data transmission capability indication based on SL relay reported by the UE, and configures the small data transmission dedicated configuration based on SL relay according to the UE capability and service characteristics, so that the terminal can perform non-activated small data transmission based on SL relay according to the small data transmission public configuration information based on SL relay and the small data transmission dedicated configuration information, thereby reducing the UE's energy consumption and unnecessary signaling overhead.

[0159] Figure 5The flowchart of some other embodiments of the small data transmission method in the direct link relay scenario of the present disclosure is shown. In this embodiment, for the scenario where the remote UE is in weak coverage or out of coverage, the remote UE has established a PC5 connection with the relay UE, and has accessed the network through the U2N relay before entering the RRC inactive state. UE1 is the remote UE, and UE2 is the relay UE.

[0160] In step 510, the base station broadcasts a message through the system to indicate that the current cell supports at least one of the small data transmission function based on SL relay and the small data transmission public configuration information based on SL relay.

[0161] In some embodiments, the base station sends the indication message and the configuration information via a SIB1 message.

[0162] In some embodiments, the SL relay-based small data transmission public configuration information includes: a data volume threshold value for executing SL relay-based small data transmission, a signal quality threshold value, and a small data transmission failure timer duration.

[0163] In step 520, UE2 sends RRC signaling to the base station to report the small data transmission capability of UE2 based on SL relay.

[0164] In step 530, UE1 sends RRC signaling to the base station through UE2 to report the small data transmission capability of UE1 based on SL relay.

[0165] In step 540, UE1 and UE2 send PC5-RRC signaling respectively to exchange small data transmission capabilities based on SL relay.

[0166] Those skilled in the art should understand that step 520 , step 550 , and step 540 may be executed in any order or may be executed simultaneously.

[0167] In step 550, the base station triggers UE1 and UE2 to enter an inactive state according to UE capabilities and service requirements, and enables a small data transmission function based on SL relay.

[0168] In step 560, the base station sends a RRCRelease message to UE2, instructing UE2 to enter an inactive state, enable a small data transmission function based on SL relay, and indicate related dedicated configuration information.

[0169] In some embodiments, the dedicated configuration information includes: a list of UE1s that are allowed to perform small data transmission based on SL relay through non-activated UE2. The configuration for each UE1 in the list includes at least one kind of information: UE1 layer 2 local ID, a list of DRBs for which the UE1 is configured with a small data transmission function, whether the SRB2 of the UE1 is allowed to perform small data transmission, and a list of SRAP configuration information. The dedicated configuration information also includes an indication of whether UE2 is allowed to perform small data transmission based on SL relay for UE1 outside the list; and information related to the dedicated configuration authorization for small data transmission based on SL relay.

[0170] In step 570, the base station sends a RRCRelease message to UE1, instructing UE1 to enter an inactive state, enable a small data transmission function based on SL relay, and indicate related dedicated configuration information.

[0171] In some embodiments, the base station may send the RRCRelease message directly to UE1, or may send the RRCRelease message to UE1 through UE2.

[0172] In some embodiments, the dedicated configuration information includes: a DRB list of UE1 configured with small data transmission function, whether the SRB2 of UE1 is allowed to perform small data transmission, an SRAP configuration information list, and whether the UE1 is allowed to select or reselect a new UE2 in an inactive state for small data transmission based on SL relay.

[0173] In step 580, UE1 triggers the small data transmission based on SL relay in the inactive state based on the service demand, and UE1 and UE2 perform the small data transmission process based on SL relay in the inactive state according to the network side configuration.

[0174] In the above embodiment, for cells that support the small data transmission function based on SL relay, the network side broadcasts an indication of supporting the function and related public configuration information, and the UE interacts with the network side and between the UEs to perform small data transmission capabilities based on SL relay. The auxiliary network side configures special configuration information for small data transmission based on SL relay according to specific UE capabilities and service characteristics, and sends the special configuration information for small data transmission to the UE through the RRCRelease message, so that the UE can perform non-activated SL relay-based small data transmission according to the small data transmission public configuration information and the small data transmission special configuration information, thereby improving the reliability of small data transmission in the non-activated state in the SL relay scenario, and saving terminal energy consumption and unnecessary signaling overhead.

[0175] Figure 6The flowchart of some other embodiments of the small data transmission method in the direct link relay scenario of the present disclosure is shown. In this embodiment, for the scenario where the remote UE is in weak coverage or out of coverage, the remote UE has established a PC5 connection with the relay UE and has accessed the network through the U2N relay before entering the RRC inactive state. UE1 is the remote UE and UE2 is the relay UE.

[0176] In step 610, the base station broadcasts a message through the system to indicate that the current cell supports at least one of the following information: a small data transmission function based on SL relay and public configuration information of small data transmission based on SL relay.

[0177] In some embodiments, the base station sends the indication message and the configuration information via a SIB1 message.

[0178] In some embodiments, the SL relay-based small data transmission public configuration information includes: a data volume threshold value, a signal quality threshold value, and a small data transmission failure timer length for executing the SL relay-based small data transmission.

[0179] In step 620, UE2 sends RRC signaling to the base station to report the small data transmission capability of UE2 based on SL relay.

[0180] In step 630, UE1 sends RRC signaling to the base station through UE2 to report the small data transmission capability of UE1 based on SL relay.

[0181] In step 640, UE1 and UE2 send PC5-RRC signaling respectively to exchange small data transmission capabilities based on SL relay.

[0182] Those skilled in the art should understand that step 420 , step 430 , and step 440 may be executed in any order or may be executed simultaneously.

[0183] In step 650, the base station sends an RRCReconfiguration message to UE2, which includes, in the existing SRAP configuration, whether small data transmission based on SL relay is supported for each RB of UE1.

[0184] In some embodiments, the existing SRAP configuration is the SL-MappingToAddMod information element in the R17 version.

[0185] In step 660, the base station sends an RRCReconfiguration message to UE1, which includes, in the existing SRAP configuration, whether each RB of UE1 supports small data transmission based on SL relay.

[0186] In step 670, the base station triggers UE1 and UE2 to enter an inactive state according to UE capabilities and service requirements, and enables a small data transmission function based on SL relay.

[0187] In step 680, the base station sends a RRCRelease message to UE2, instructing UE2 to enter an inactive state, enable a small data transmission function based on SL relay, and indicate related dedicated configuration information.

[0188] In some embodiments, the dedicated configuration information includes a list of remote UEs that are allowed to perform small data transmission based on SL relay through an inactive relay UE. The configuration for each remote UE in the list includes at least one kind of information: remote UE layer 2 local ID, DRB list of the remote UE configured with small data transmission function, and whether SRB2 of the remote UE is allowed to perform small data transmission. The dedicated configuration information also includes an indication of whether the relay UE is allowed to perform small data transmission based on SL relay for remote UEs outside the list; and information related to the dedicated configuration authorization of small data transmission based on SL relay.

[0189] In step 690, the base station sends a RRCRelease message to UE1, instructing UE1 to enter an inactive state, enable a small data transmission function based on SL relay, and indicate related dedicated configuration information.

[0190] In some embodiments, the dedicated configuration information includes: a DRB list of the remote UE configured with the small data transmission function, whether the SRB2 of the remote UE is allowed to perform small data transmission, and whether the remote UE is allowed to select or reselect a new relay UE in an inactive state to perform small data transmission based on SL relay.

[0191] In step 6100, UE1 triggers the small data transmission based on SL relay in the inactive state based on business needs, and UE1 and UE2 perform the small data transmission process based on SL relay in the inactive state according to the network side configuration.

[0192] In the above embodiment, for cells that support the small data transmission function based on SL relay, the network side broadcasts an indication of supporting the function and related public configuration information, and the UE interacts with the network side and between the UEs to perform small data transmission capabilities based on SL relay. The base station sends information on whether each RB of the remote UE supports small data transmission based on SL relay to the UE through an RRC reconfiguration message, and sends small data transmission-specific configuration information to the UE through an RRC reconfiguration message, so that the UE can perform non-activated SL relay-based small data transmission according to the small data transmission public configuration information and the small data transmission-specific configuration information, thereby improving the reliability of small data transmission in the non-activated state in the SL relay scenario, and saving terminal energy consumption and unnecessary signaling overhead.

[0193] Figure 7 The flowchart is a schematic diagram of other embodiments of the small data transmission method in the direct link relay scenario of the present disclosure. In this embodiment, UE1 and UE2 are both in the RRC connection state, and no PC5 connection is established. UE1 accesses the network through the U2N relay in the inactive state. The UE1 supports the U2N relay function and has the ability to be a remote UE. The UE2 supports the U2N relay function and has the ability to be a relay UE. After UE1 enters the inactive state, the signal quality deteriorates and it is impossible to directly transmit small data. UE2 is selected as the relay UE to perform small data transmission based on the SL relay.

[0194] In step 710, the base station broadcasts a message through the system to indicate that the current cell supports at least one of a small data transmission function based on SL relay and public configuration information of small data transmission based on SL relay.

[0195] In some embodiments, the small data transmission public configuration information includes a data volume threshold for performing SL relay-based small data transmission, a PC5 interface signal quality threshold, a small data transmission failure timer duration, and the like.

[0196] In step 720, UE2 sends RRC signaling to the base station to report the small data transmission capability based on SL relay.

[0197] In step 730, UE1 sends RRC signaling to the base station to report the small data transmission capability based on SL relay.

[0198] Those skilled in the art should understand that step 720 and step 730 may be executed in any order or simultaneously.

[0199] In step 740, the base station triggers UE1 and UE2 to enter an inactive state according to UE capabilities and service requirements, and enables a small data transmission function based on SL relay.

[0200] In step 750, the base station sends a RRCRelease message to UE2, instructing UE2 to enter an inactive state, enable a small data transmission function based on SL relay, and indicate related dedicated configuration information.

[0201] The dedicated configuration information includes whether a UE with U2N relay capability is allowed to perform SL relay-based small data transmission for other UEs, and information related to the dedicated configuration authorization of small data transmission based on SL relay.

[0202] In step 760, the base station sends a RRCRelease message to UE1, instructing UE1 to enter an inactive state, enable a small data transmission function based on SL relay, and indicate related dedicated configuration information.

[0203] The dedicated configuration information includes whether the remote UE is allowed to select or reselect a new relay UE in an inactive state to perform small data transmission based on the SL relay, and a list of candidate relay UEs, which at least includes candidate relay ID information.

[0204] In step 770, UE1 triggers small data transmission based on SL relay according to service requirements and network configuration.

[0205] In step 780, UE1 selects UE2 as a relay UE and establishes a PC5-RRC connection with UE2.

[0206] In step 790, UE1 and UE2 send PC5-RRC signaling respectively to exchange small data transmission capabilities based on SL relay.

[0207] In step 7100, UE1 and UE2 perform a small data transmission process based on SL relay in an inactive state according to the network side configuration.

[0208] In the above embodiment, the function of RRC non-activated small data transmission based on U2N relay is added. When the UE is in the non-activated state, the UE selects or reselects the relay UE to perform small data transmission based on SL relay, thereby improving the reliability of small data transmission in the non-activated state in the SL relay scenario, thereby saving terminal energy consumption and unnecessary signaling overhead, and improving user experience.

[0209] Figure 8 This is a structural diagram of some embodiments of a user device disclosed in the present invention, wherein the user device includes a first transceiver module 810, which is configured to receive SL relay-based small data transmission configuration information sent by a network side, wherein the SL relay-based small data transmission configuration information is used to enable the UE to perform inactive SL relay-based small data transmission when it is in an inactive state and meets small data transmission conditions.

[0210] In some embodiments, the SL relay-based small data transmission configuration information includes a first message and a second message.

[0211] In some embodiments, the first message includes at least one of an indication of whether the current cell supports a small data transmission function based on SL relay and public configuration information of small data transmission based on SL relay. The first message is, for example, a system message.

[0212] When the SL relay-based small data transmission configuration information only includes an indication of whether the current cell supports the SL relay-based small data transmission function, that is, when the network side only indicates support for the SL relay-based small data transmission function but does not configure the small data transmission-related public configuration parameters for the SL relay scenario, the UE uses the existing small data transmission public configuration parameters for SL relay-based small data transmission.

[0213] In some embodiments, the current cell is a wireless area controlled by a base station that sends the SL relay-based small data transmission configuration information.

[0214] In some other embodiments, the second message includes: indication information that the UE enters an inactive state, and dedicated configuration information for small data transmission based on SL relay of the UE. The second message is an RRC signaling message.

[0215] In the above embodiment, the user equipment can implement small data transmission based on SL relay in an inactive state. Since the user equipment can implement small data transmission based on SL relay without being in a connected state, the energy consumption of the user equipment is reduced.

[0216] In some other embodiments of the present disclosure, the first transceiver module 810 is further configured to report the SL relay-based small data transmission capability of the UE to the network side.

[0217] The first transceiver module 810 is also configured to interact with the opposite end UE about the SL relay-based small data transmission capability of the UE.

[0218] In other embodiments, Fig. 9 The user equipment further includes a first execution module 910, which is configured to execute inactive state SL relay-based small data transmission when inactive state and meeting small data transmission conditions.

[0219] Fig.10 The schematic diagram of the structure of some other embodiments of the user equipment of the present disclosure is shown in FIG. 1 , wherein the user equipment 1000 includes a memory 1010 and a processor 1020. The memory 1010 may be a disk, a flash memory, or any other non-volatile storage medium. The memory is used to store the instructions in the above embodiments. The processor 1020 is coupled to the memory 1010 and may be implemented as one or more integrated circuits, such as a microprocessor or a microcontroller. The processor 1020 is used to execute the instructions stored in the memory.

[0220] In some embodiments, the processor 1020 is coupled to the memory 1010 via a BUS 1030. The user device 1000 may also be connected to an external storage system 1050 via a storage interface 1040 to call external data, and may also be connected to a network or another computer system (not shown) via a network interface 1060. This will not be described in detail here.

[0221] In this embodiment, the memory stores data instructions, and the processor processes the instructions, thereby reducing the energy consumption of the user equipment and reducing the signaling overhead.

[0222] Fig.11 This is a structural diagram of some embodiments of the base station disclosed in the present invention, wherein the base station includes a second transceiver module 1110, which is configured to send small data transmission configuration information based on SL relay to UE, wherein the small data transmission configuration information based on SL relay is used to enable the UE to perform small data transmission based on SL relay in an inactive state when it is in an inactive state and meets small data transmission conditions.

[0223] In some embodiments, the SL relay-based small data transmission configuration information includes a first message and a second message.

[0224] In some embodiments, the first message includes: an indication of whether the current cell supports a small data transmission function based on SL relay and at least one of public configuration information of small data transmission based on SL relay. The first message is, for example, a system message.

[0225] When the SL relay-based small data transmission configuration information only includes an indication of whether the current cell supports the SL relay-based small data transmission function, that is, when the network side only indicates support for the SL relay-based small data transmission function but does not configure the small data transmission-related public configuration parameters for the SL relay scenario, the UE uses the existing small data transmission public configuration parameters for SL relay-based small data transmission.

[0226] In some embodiments, the current cell is a wireless area controlled by a base station that sends the SL relay-based small data transmission configuration information.

[0227] In some other embodiments, the second message includes: indication information that the UE enters an inactive state, and dedicated configuration information for small data transmission based on SL relay of the UE. The second message is an RRC signaling message.

[0228] In other embodiments, Fig.12 As shown, the base station also includes a second execution module 1210, and the second transceiver module 1110 is also configured to receive the small data transmission capability based on SL relay reported by the user equipment. The second execution module 1210 determines whether it is necessary to enable the small data transmission function based on SL relay for the UE according to the small data transmission capability based on SL relay and service requirements of the UE.

[0229] Fig.131 is a schematic diagram of the structure of other embodiments of the base station of the present disclosure, wherein the base station 1300 includes a memory 1310 and a processor 1320. The memory 1310 may be a disk, a flash memory, or any other non-volatile storage medium. The memory is used to store the instructions in the above embodiments. The processor 1320 is coupled to the memory 1310 and may be implemented as one or more integrated circuits, such as a microprocessor or a microcontroller. The processor 1320 is used to execute the instructions stored in the memory.

[0230] In some embodiments, the processor 1320 is coupled to the memory 1310 via a BUS 1330. The base station 1300 can also be connected to an external storage system 1350 via a storage interface 1340 to call external data, and can also be connected to a network or another computer system (not shown) via a network interface 1360. No further detailed description will be given here.

[0231] In this embodiment, the memory stores data instructions, and the processor processes the instructions, so that the terminal can perform small data transmission based on SL relay in an inactive state.

[0232] In some other embodiments of the present disclosure, a user equipment and a base station are also protected, wherein the user equipment includes a remote user equipment and at least one relay user equipment, and the base station may be one or more base stations.

[0233] In other embodiments, a computer-readable storage medium stores computer program instructions, which implement the steps of the methods in the above-mentioned embodiments when executed by a processor. It should be understood by those skilled in the art that the embodiments of the present disclosure may be provided as methods, devices, or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present disclosure may take the form of a computer program product implemented on one or more computer-usable non-transient storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0234] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0235] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0236] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0237] So far, the present disclosure has been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0238] Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A small data transmission method in a direct link relay scenario, comprising: The user equipment UE receives small data transmission configuration information based on the direct link SL relay sent by the network side, wherein the small data transmission configuration information based on the SL relay is used to enable the UE to perform inactive SL relay-based small data transmission when it is in an inactive state and meets the small data transmission conditions.

2. The small data transmission method according to claim 1, wherein: The UE receives the SL relay-based small data transmission configuration information sent by the network side, including: The UE receives a first message and a second message including the SL relay-based small data transmission configuration information sent by the network side, wherein: The first message includes at least one of an indication of whether the current cell supports a small data transmission function based on an SL relay and public configuration information of small data transmission based on an SL relay; and The second message includes indication information that the UE enters an inactive state and dedicated configuration information for small data transmission based on SL relay of the UE.

3. The small data transmission method according to claim 2, wherein: The SL relay-based small data transmission public configuration information includes at least one of the following: A data volume threshold value, used to instruct the UE to determine whether the amount of data to be transmitted meets the data volume condition for executing the small data transmission based on the SL relay in the inactive state; A signal quality threshold value, used to instruct the UE to determine whether the signal quality of the direct communication PC5 interface meets the signal quality condition for executing the inactive SL relay-based small data transmission; The duration of the small data transmission failure timer is used to instruct the UE to determine the timer value for the small data transmission based on the SL relay in the inactive state.

4. The small data transmission method according to claim 2, wherein: The small data transmission dedicated configuration information includes an instruction to enable or release a small data transmission function based on an SL relay, wherein, in the case of an instruction to enable a small data transmission function based on an SL relay, the small data transmission dedicated configuration information further includes at least one of the following: For a UE acting as a relay node, a list of SL-relay-based small data transmission configuration information of one or more remote nodes associated with the relay node is included to indicate that the relay node is allowed to perform inactive small data transmission for the one or more associated remote nodes through the user equipment to network U2N relay; For a UE as a remote node, at least one configuration information for small data transmission in a SL relay scenario is included; For a UE with relay capability, indicating whether SL-relay-based small data transmission can be performed for other remote nodes that are not in one or more remote nodes associated with the UE with relay capability; SL relay-based small data transmission dedicated configuration authorization related information, used to indicate the specific configuration authorization information used by the relay node when forwarding small data of the remote node in the inactive state; For remote nodes that have access to the network through relay nodes, it indicates whether it is possible to select or reselect a new relay node in an inactive state for small data transmission based on SL relay.

5. The small data transmission method according to claim 4, wherein: The SL relay-based small data transmission configuration information list includes: At least one of the identification information of the remote node, the list of data radio bearers configured with small data transmission function of the remote node, the indication information of whether the signaling radio bearer SRB2 of the remote node is allowed to perform small data transmission, and the list of configuration information of the direct link relay adaptation protocol SRAP layer.

6. The small data transmission method according to claim 4, wherein: The at least one configuration information for small data transmission in the SL relay scenario includes: The remote node is configured with at least one of a list of data radio bearers with small data transmission function, indication information of whether the remote node's signaling radio bearer SRB2 is allowed to perform small data transmission based on SL relay, and a list of direct link relay adaptation protocol SRAP layer configuration information.

7. The small data transmission method according to claim 4, wherein: The second message also includes whether the remote node and the relay node support small data transmission based on SL relay for each radio bearer in the direct link relay adaptation protocol SRAP configuration.

8. The small data transmission method according to claim 7, wherein: The SL relay-based small data transmission configuration information list includes: At least one of the identification information of the remote node, a list of data radio bearers of the remote node configured with a small data transmission function, and indication information of whether to allow the signaling radio bearer SRB2 of the remote node to perform small data transmission.

9. The small data transmission method according to claim 7, wherein: The at least one configuration information for small data transmission in the SL relay scenario includes: The remote node is configured with at least one of a list of data radio bearers with a small data transmission function and indication information of whether the signaling radio bearer SRB2 of the remote node is allowed to perform small data transmission based on SL relay.

10. The small data transmission method according to claim 4, wherein: For a remote node that has access to a network through a relay node, the small data transmission dedicated configuration information also includes a candidate relay node list, which is used to assist the remote node in selecting or reselecting a relay node in an inactive state.

11. The small data transmission method according to claim 2, wherein: The indication of whether the current cell supports the small data transmission function based on SL relay includes at least one of the following: Indicating that the current cell supports at least one of a remote node and a relay node to perform inactive small data transmission in a user equipment to network U2N relay scenario; By configuring the common configuration information for small data transmission in the SL relay scenario, it is indicated that the current cell supports the small data transmission function based on the SL relay.

12. The small data transmission method according to claim 2, wherein: The first message is a system message; and The second message is an RRC signaling message.

13. The small data transmission method according to any one of claims 1 to 12, further comprising: The UE reports the SL relay-based small data transmission capability of the UE to the network side; as well as The UE exchanges the SL relay-based small data transmission capability of the UE with the opposite UE.

14. The small data transmission method according to claim 13, wherein: The SL relay-based small data transmission capability of the UE includes at least one of the following: When the UE acts as a remote node, whether it supports the inactive small data transmission function when accessing the network through the user equipment to network U2N relay; When the UE acts as a relay node, whether it supports a small data transmission function of forwarding a remote node in an inactive state in a U2N relay scenario; Whether the UE supports the use of a configuration authorization method to perform small data transmission in an inactive state based on a U2N relay scenario; Whether the UE supports the use of random access in a U2N relay scenario to perform small data transmission in an inactive state; Whether the UE supports small data transmission of signaling radio bearer SRB2 in an inactive state using a configuration authorization method or a random access method in a U2N relay scenario.

15. The small data transmission method according to claim 14, wherein: When the UE acts as a remote node, the capability parameter of whether to support the inactive small data transmission function when accessing the network through the U2N relay includes: supporting only small data transmission triggered by the terminal, supporting only small data transmission terminated by the terminal, and supporting both small data transmission triggered by the terminal and small data transmission terminated by the terminal; and When the UE acts as a relay node, the capability parameters of whether it supports the small data transmission function of forwarding the remote node in an inactive state in the U2N relay scenario include: only supporting small data transmission triggered by the terminal, only supporting small data transmission terminated by the terminal, and one of small data transmission triggered by the terminal and small data transmission terminated by the terminal at the same time.

16. The small data transmission method according to claim 13, wherein: In the case that the UE and the opposite UE do not establish a direct communication PC5 interface connection, after the PC5 connection is established, the UE's small data transmission capability based on SL relay is exchanged with the opposite UE.

17. A small data transmission method in a direct link relay scenario, comprising: Small data transmission configuration information based on a direct link SL relay is sent to a user equipment UE, wherein the small data transmission configuration information based on the SL relay is used to enable the UE to perform small data transmission based on the SL relay in an inactive state when it is in an inactive state and meets a small data transmission condition.

18. The small data transmission method according to claim 17, wherein: The sending of the SL relay-based small data transmission configuration information to the UE includes: Sending a first message and a second message including the SL relay-based small data transmission configuration information to the UE, wherein: The first message includes at least one of an indication of whether the current cell supports a small data transmission function based on an SL relay and public configuration information of small data transmission based on an SL relay; and The second message includes indication information that the UE enters an inactive state and dedicated configuration information for small data transmission based on SL relay of the UE.

19. The small data transmission method according to claim 18, wherein: The SL relay-based small data transmission public configuration information includes at least one of the following: A data volume threshold value, used to instruct the UE to determine whether the amount of data to be transmitted meets the data volume condition for executing the small data transmission based on the SL relay in the inactive state; A signal quality threshold value, used to instruct the UE to determine whether the signal quality of the PC5 interface meets the signal quality condition for executing the inactive SL relay-based small data transmission; as well as The duration of the small data transmission failure timer is used to instruct the UE to determine the timer value for the small data transmission based on the SL relay in the inactive state.

20. The small data transmission method according to claim 18, wherein: The small data transmission dedicated configuration information includes an instruction to enable or release a small data transmission function based on an SL relay, wherein, in the case of an instruction to enable a small data transmission function based on an SL relay, the small data transmission dedicated configuration information further includes at least one of the following: For a UE acting as a relay node, a list of SL-relay-based small data transmission configuration information of one or more remote nodes associated with the relay node is included to indicate that the relay node is allowed to perform inactive small data transmission for the one or more associated remote nodes through the user equipment to network U2N relay; For a UE as a remote node, at least one configuration information for small data transmission in a SL relay scenario is included; For a UE with relay capability, indicating whether SL-relay-based small data transmission can be performed for other remote nodes that are not in one or more remote nodes associated with the UE with relay capability; Related information about the authorization of small data transmission based on SL relay; For remote nodes that have access to the network through relay nodes, it indicates whether it is possible to select or reselect a new relay node in an inactive state for small data transmission based on SL relay.

21. The small data transmission method according to any one of claims 18 to 20, further comprising: Receive the small data transmission capability based on SL relay reported by the UE.

22. The small data transmission method according to claim 21, further comprising: According to the SL relay-based small data transmission capability and service requirements of the UE, it is determined whether it is necessary to enable the SL relay-based small data transmission function for the UE.

23. The small data transmission method according to claim 21, wherein: The SL relay-based small data transmission capability of the UE includes at least one of the following: When the UE acts as a remote node, whether it supports the inactive small data transmission function when accessing the network through the user equipment to network U2N relay; When the UE acts as a relay node, whether it supports a small data transmission function of forwarding a remote node in an inactive state in a U2N relay scenario; Whether the UE supports the use of a configuration authorization method to perform small data transmission in an inactive state based on a U2N relay scenario; Whether the UE supports the use of random access in a U2N relay scenario to perform small data transmission in an inactive state; Whether the UE supports small data transmission of signaling radio bearer SRB2 in an inactive state using a configuration authorization method or a random access method in a U2N relay scenario.

24. A user equipment, comprising: The first transceiver module is configured to receive small data transmission configuration information based on the direct link SL relay sent by the network side, wherein the small data transmission configuration information based on the SL relay is used to enable the UE to perform inactive SL relay-based small data transmission when it is in an inactive state and meets the small data transmission conditions.

25. A user equipment, comprising: Memory; as well as A processor coupled to the memory, wherein the processor is configured to execute the small data transmission method according to any one of claims 1 to 16 based on instructions stored in the memory.

26. A base station, comprising: The second transceiver module is configured to send small data transmission configuration information based on the direct link SL relay to the user equipment UE, wherein the small data transmission configuration information based on the SL relay is used to enable the UE to perform small data transmission based on the SL relay in an inactive state when it is in an inactive state and meets the small data transmission conditions.

27. A base station, comprising: Memory; as well as A processor coupled to the memory, wherein the processor is configured to execute the small data transmission method according to any one of claims 17 to 23 based on instructions stored in the memory.

28. A small data transmission system in a direct link relay scenario, comprising: The user equipment of claim 24 or 25, wherein the user equipment comprises a remote user equipment and at least one relay user equipment; and At least one base station as claimed in claim 26 or 27.

29. A non-transitory computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, implement the small data transmission method according to any one of claims 1 to 23.

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