Information transmission method and communication apparatus

Abstract

Provided in the embodiments of the present application are an information transmission method and a communication apparatus, which can be used for a terminal to determine in a multi-hop relay scenario the duration of a timer used for establishing, or re-establishing, or restoring a radio resource control (RRC) connection. For example, the communication method executed by a first terminal comprises: receiving first indication information from a second terminal, the first indication information being used for determining information about a first hop count of a first link, the first hop count being associated with the number of network devices and / or terminals on the first link, and the first link being a wireless link for the first terminal to connect to the network devices via the second terminal; and, on the basis of the information about the first hop count, determining the duration of a first timer, the duration of the first timer being the duration corresponding to the first link.

Description

Information transmission method and communication device

[0001] The present application claims priority to the Chinese patent application No. 202411104081.X, filed on August 9, 2024, and entitled "Information transmission method and communication device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication, in particular to an information transmission method and a communication device. BACKGROUND

[0003] Sidelink (SL) user equipment (UE) to network relay (UE-to-network relay) technology (or also called SL U2N relay technology) is a technology in which one UE helps another UE to communicate with a network device.

[0004] However, if the above-mentioned UE is connected to the network device through multiple UEs (i.e., multi-hop relay), how to determine the length of the timer for establishing, or re-establishing, or resuming a radio resource control (RRC) connection is a problem to be solved at present. SUMMARY

[0005] The information transmission method and the communication device provided by the embodiments of the present application can be used to determine the length of the timer for establishing, or re-establishing, or resuming a radio resource control (RRC) connection in a multi-hop relay scenario.

[0006] To achieve the above-mentioned purpose, the embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, a communication method is provided, which can be executed by a first terminal or a chip or processing module in the first terminal. Taking the first terminal as an example, the method comprises: receiving first indication information from a second terminal, the first indication information being information for determining a first hop number of a first link, the first hop number being associated with a number of network devices and / or terminals on the first link, the first link being a wireless link through which the first terminal connects to a network device via the second terminal; and determining a length of a first timer according to the information of the first hop number, the length of the first timer being a length corresponding to the first link.

[0008] Since in the embodiments of the present application, the first terminal can determine the information of the first hop number of the first link through which the first terminal connects the network device through the second terminal by the first indication information from the second terminal, and further determine the time length of the first timer suitable for establishing connection with the network device on the first link according to the information of the first hop number of the first link.

[0009] In a possible implementation, the first hop number is the number of terminals on the first link, or the first hop number is the sum of the number of links directly connecting the terminals on the first link and the number of links directly connecting the terminals on the first link to the network device. For example, the first hop number is the number of terminals on the first link, which can be understood as the number of links directly connecting the terminals on the first link. Assuming that the number of terminals on the first link (including the first terminal) is N, then the number of links directly connecting the terminals on the first link is N-1, that is, the first hop number is N-1, and N is an integer greater than or equal to 1. For another example, assuming that the number of terminals on the first link is N and the number of network devices is 1 (usually 1 network device), then the first hop number is N, the number of links directly connecting the terminals on the first link is N-1, and the number of links directly connecting the terminals on the first link to the network device is 1.

[0010] In a possible implementation, the time length of the first timer is determined according to the information of the first hop number, including: the time length of the first timer is determined according to the information of the first hop number and the first time length, and the first time length is the time length corresponding to the link directly connecting the terminals on the first link. That is, the first terminal can determine the time length of the first timer suitable for establishing connection with the network device on the first link according to the information of the first hop number and the first time length corresponding to the connection established on the link directly connecting the terminals on the first link, so that the first terminal can receive the message transmitted by the network device for establishing connection and avoid interrupting the connection incorrectly.

[0011] In a possible implementation, the first time length is indicated by the network device, or the first time length is determined according to a second time length and a third time length, the second time length being a time length corresponding to that the terminal directly connects the network device, and the third time length being a time length corresponding to that the terminal connects the network device through a relay. That is, when the first time length is indicated by the network device, the first terminal can determine the time length of the first timer based on the indicated first time length and the information of the first hop number, and thus the complexity of determining the time length of the first timer by the first terminal can be reduced. In addition, the first terminal can also determine the first time length according to the second time length and the third time length, which can provide flexibility in determining the first time length. It can be understood that, when the second time length is a time length of a timer configured by the network device through a system information block (SIB) 1, and the third time length is a time length of a timer configured through SIB 12, the first time length is determined according to the second time length and the third time length, which is less likely to change the network side and is easy to deploy.

[0012] It can also be understood that, when the first time length is indicated by the network device, the network device can configure the first time length through SIB, for example, indicating in SIB 12 or other SIBs, which is not limited in the embodiments of the present application.

[0013] In a possible implementation, the first time length is determined according to the second time length and the third time length, including that the first time length is a difference between the second time length and the third time length. That is, the first terminal can obtain the first time length by subtracting the second time length from the third time length, and the complexity of determining the first time length on the first terminal side can be reduced. It should be understood that the difference between the first time length, the second time length and the third time length is only an example, and the difference between the second time length and the third time length can also be offset.

[0014] In a possible implementation, the first time length is determined according to the second time length and the third time length, and the time length of the first timer is determined according to the information of the first hop number and the first time length, including that the time length of the first timer is determined according to the information of the first hop number, the second time length and the third time length. That is, the first terminal can directly determine the time length of the first timer suitable for establishing a connection with the network device on the first link according to the information of the first hop number, the second time length and the third time length, so that the first terminal can receive the message transmitted by the network device for establishing a connection and avoid interrupting the connection incorrectly.

[0015] In a possible implementation, the length of the first timer is determined according to the information of the first hop number, including: the length of the first timer is determined according to the second length and the third length, the second length is a length corresponding to that the terminal directly connects to the network device, and the third length is a length corresponding to that the terminal connects to the network device through the relay. That is, the first terminal can directly determine the length of the first timer suitable for establishing a connection with the network device on the first link according to the information of the first hop number, the second length, and the third length, so that the first terminal can receive the message transmitted by the network device for establishing a connection, and avoid mistakenly interrupting the connection.

[0016] In a possible implementation, the first indication information indicates information of a second hop number of the second terminal connecting to the network device, and the second hop number is associated with a number of terminals on a wireless link of the second terminal connecting to the network device; or the first indication information is an identifier used to indicate a relay service provided by the second terminal. It can be understood that the second hop number is similar to the definition of the first hop number, and the second hop number can be the number of terminals on a wireless link of the second terminal connecting to the network device, or the number of links directly connected between terminals. In addition, the information of the second hop number is used to determine the information of the first hop number. For example, if the first terminal is directly connected to the second terminal, the first hop number is actually the second hop number plus 1. It can also be understood that through the identifier used to indicate the relay service provided by the second terminal, the type of the relay service provided by the second terminal can be determined, and then whether the second terminal is directly connected to the network device can be determined, and then the information of the first hop number can be determined. For example, the identifier used to indicate the relay service provided by the second terminal can be a relay service code (RSC), or other identifiers used to indicate the relay service provided by the second terminal.

[0017] In a possible implementation, the condition for triggering the stopping of the first timer within the length of the first timer includes at least one of the following: determining that a radio link failure occurs, a link switching occurs, or a relay reselection occurs. That is, the first terminal stops the first timer when it is determined that the first terminal and / or the second terminal has a radio link failure, a link switching, or a relay reselection.

[0018] In a possible implementation, the method provided in the first aspect further includes: receiving second indication information from the second terminal, the second indication information being used to indicate at least one of the following: a radio link failure, a link switching, a relay reselection, or a cell switching of the second terminal. That is, the first terminal can determine the connection state of the second terminal providing the relay service for the first terminal through the second indication information, and then can stop the first timer in time based on the second indication information, so as to enter other connection procedures.

[0019] In a possible implementation, the method provided by the first aspect further includes: receiving third indication information from the second terminal, the third indication information indicating that a connection state of the second terminal changes, and / or information of a third hop number of the second terminal connecting the network device. That is, the first terminal receives the third indication information from the second terminal, can perceive whether the information of the first hop number changes, and further can determine whether to adjust the length of the first timer.

[0020] In a possible implementation, the third indication information indicates that the connection state of the second terminal changes, including: the connection state changes from a first state to a second state; and the connection state changes from the first state to the second state includes: the second terminal changes from directly connecting the network device to connecting the network device through a relay terminal; or the second terminal changes from connecting the network device through a relay to directly connecting the network device; or a relay terminal between the second terminal and the network device changes. That is, by indicating the connection states of the second terminal before and after the change through the third indication information, whether the first hop number changes can be determined.

[0021] In a possible implementation, the method provided by the first aspect further includes: determining information of an updated first hop number according to the third indication information; and determining the length of the first timer according to the information of the updated first hop number. That is, the first terminal can determine the first hop number after the change according to the third indication information, can determine the length of the first timer through the information of the updated first hop number, and adaptively adjusts the length of the first timer according to the information of the changed first hop number.

[0022] In a possible implementation, the first timer is used for a radio resource control (RRC) connection establishment process, or a re-establishment process, or a recovery process.

[0023] The second aspect provides a communication method, which can be executed by the second terminal or a chip or processing module in the second terminal, and is taken as an example of the second terminal. The method includes: determining first indication information, the first indication information indicating information of a second hop number of the second terminal connecting a network device, the second hop number being associated with a number of terminals on a wireless link of the second terminal connecting the network device; or the first indication information being an identifier of a relay service provided by the second terminal; and sending the first indication information to a first terminal.

[0024] In a possible implementation, the method provided by the second aspect further includes: sending second indication information to the first terminal, the second indication information being used to indicate at least one of the following: the second terminal has a radio link failure, a link switching, a relay reselection, or a cell switching.

[0025] In a possible implementation, the method provided by the second aspect further includes: sending, to the first terminal, third indication information, the third indication information indicating that the connection state of the second terminal changes, and / or information about a third hop number of the second terminal connecting the network device.

[0026] In a possible implementation, the third indication information indicates that the connection state of the second terminal changes, including: the connection state changes from a first state to a second state; and the connection state changes from the first state to the second state includes: the second terminal changes from being directly connected to the network device to being connected to the network device through the relay device, or the second terminal changes from being connected to the network device through the relay device to being directly connected to the network device.

[0027] It should be understood that the beneficial effects of the second aspect and any implementation thereof can be specifically referred to the beneficial effects of the first aspect and any implementation thereof, which will not be repeated here.

[0028] The third aspect provides a communication apparatus for implementing the above-mentioned various methods. The communication apparatus can be the first terminal or the second terminal in any of the above-mentioned aspects or any implementation thereof, or an apparatus including the first terminal or the second terminal, or an apparatus included in the first terminal or the second terminal, such as a chip. The communication apparatus includes modules, units, or means for implementing the above-mentioned methods, which can be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above-mentioned functions.

[0029] In some possible designs, the communication apparatus can include a processing module and a transceiver module. The transceiver module, which can also be referred to as a transceiver unit, is configured to implement the sending and / or receiving functions in any of the above-mentioned aspects and any possible implementation thereof. The transceiver module can be composed of a transceiver circuit, a transceiver, a transceiver, or a communication interface. The processing module can be configured to implement the processing functions in any of the above-mentioned aspects and any possible implementation thereof.

[0030] In some possible designs, the transceiver module includes a sending module and a receiving module, which are respectively configured to implement the sending and receiving functions in any of the above-mentioned aspects and any possible implementation thereof.

[0031] The fourth aspect provides a communication apparatus, including: at least one processor; the processor is configured to execute a computer program or instructions to enable the communication apparatus to perform the method in any of the above-mentioned aspects.

[0032] In a possible implementation, the communication apparatus further includes the memory. Optionally, the memory is coupled with the processor, the memory can be integrated with the processor, or the memory can be independent of the processor. Optionally, the processor is configured to execute the computer program or the instructions stored in the memory.

[0033] In a possible implementation, the memory is independent of the communication apparatus.

[0034] In a possible implementation, the communication apparatus further includes a communication interface configured to communicate with a module outside the communication apparatus.

[0035] The communication apparatus can be the first terminal or the second terminal in any of the aspects or implementations of the aspects described above, or an apparatus including the first terminal or the second terminal, or an apparatus included in the first terminal or the second terminal, such as a chip.

[0036] In a fifth aspect, a computer-readable storage medium is provided, which stores computer programs or instructions, and when the computer programs or instructions are executed on a communication apparatus, the communication apparatus is enabled to perform the method in any of the aspects or implementations of the aspects described above.

[0037] In a sixth aspect, a computer program product is provided, which includes instructions, and when the computer program product is executed on a communication apparatus, the communication apparatus is enabled to perform the method in any of the aspects or implementations of the aspects described above.

[0038] In a seventh aspect, a communication apparatus (for example, the communication apparatus can be a chip or a chip system) is provided, which includes a processor configured to implement the functions in any of the aspects or implementations of the aspects described above.

[0039] In some possible designs, the communication apparatus includes a memory configured to store necessary program instructions and data.

[0040] In some possible designs, when the apparatus is a chip system, the apparatus can be composed of a chip, or can include a chip and other discrete devices.

[0041] It can be understood that, when the communication apparatus in any of the third aspect to the seventh aspect is a chip, the sending action / function described above can be understood as output, and the receiving action / function described above can be understood as input.

[0042] The technical effects brought by the design in any of the third aspect to the seventh aspect can refer to the technical effects brought by the different design in the first aspect or the second aspect, which will not be repeated here.

[0043] Eighthly, a communication system is provided, comprising: a first terminal and a second terminal as described in any of the preceding aspects and any implementation thereof. Attached Figure Description

[0044] Figure 1 is a schematic diagram of a scenario in which UE#1 and UE#2 communicate directly via PC5 according to an embodiment of this application;

[0045] Figure 2 is a schematic diagram of a unicast connection establishment process provided in an embodiment of this application;

[0046] Figure 3 is a schematic diagram of a communication architecture for an SL U2N relay provided in an embodiment of this application;

[0047] Figure 4 is a schematic diagram of a protocol stack structure for an L2 U2N relay provided in an embodiment of this application;

[0048] Figure 5 is a schematic diagram of an RRC establishment process provided in an embodiment of this application;

[0049] Figure 6 is a flowchart of an RRC connection re-establishment process provided in an embodiment of this application;

[0050] Figure 7 is a flowchart of an RRC connection recovery process provided in an embodiment of this application;

[0051] Figure 8 is a schematic diagram of a communication architecture for SL multi-hop relay provided in an embodiment of this application;

[0052] Figure 9 is a schematic diagram of the architecture of a possible, non-limiting communication system provided in an embodiment of this application;

[0053] Figure 10 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0054] Figure 11 is a schematic diagram of a scenario in which the number of first hops changes, according to an embodiment of this application;

[0055] Figures 12 and 13 are schematic diagrams of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0056] To facilitate understanding of the technical solutions provided in the embodiments of this application, a brief introduction to the relevant technical terms is given first. The brief introduction is as follows:

[0057] First, the sidelink (SL):

[0058] In wireless communication, user equipment (UE) and UE can communicate with each other with or without network equipment. The interface (or air interface, or air interface) between UE and UE is called PC5, which is similar to the air interface Uu between UE and RAN equipment. In addition, the link between UE and UE is called SL, and UE and UE can directly transmit data through SL without going through the network, which can effectively reduce the communication delay.

[0059] For example, FIG. 1 is a schematic diagram of a scenario of direct communication between UE#1 and UE#2 through PC5 provided by an embodiment of the present application. As shown in FIG. 1, the wireless link between UE#1 and UE#2 is called SL, and the interface between them is PC5.

[0060] It can be understood that the air interface protocol stack structure followed by PC5 is similar to the air interface protocol stack structure followed by Uu, which can be divided into three layers and two faces. The three layers include physical (PHY) layer (or layer 1 (L1)), data link layer (or layer 2 (L2)), and network layer (or layer 3 (L3)), and the two faces include control plane for transmitting control signaling and user plane for transmitting service data. L2 is logically divided into service data adaptation protocol (SDAP) layer, packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, and media access control (MAC) layer from top to bottom.

[0061] SL supports broadcast, groupcast, and unicast communication modes. Among them, the broadcast in SL is similar to the broadcast of system information (SI) by the RAN equipment, and the UE can send broadcast service data without encryption, and other UEs within the wireless coverage of the UE can receive the broadcast service data.

[0062] Groupcast can mean that any UE in a group can transmit and receive groupcast service data.

[0063] Unicast is similar to data communication after a radio access control (RRC) connection is established between a UE and a network device, that is, a unicast connection is first established between two UEs, and then data communication can be performed based on negotiated identities. It can be understood that, compared with broadcast, in unicast, data communication can only be performed between the two UEs that have established a unicast connection.

[0064] For unicast communication, one unicast communication on the SL corresponds to a pair of identities, that is, a source L2 identifier (ID) and a destination L2 ID. The source L2 ID and the destination L2 ID are included in a subheader of each SL MAC layer protocol data unit (PDU), so that data can be transmitted from a sending end to a correct receiving end.

[0065] The following describes establishment of a unicast connection in a unicast communication process.

[0066] The unicast connection is established through a unicast connection establishment process between the two UEs. The UE that initiates the unicast connection establishment process is referred to as an initiating UE, and the UE opposite to the initiating UE is referred to as a target UE. The initiating UE and the target UE can establish a unicast connection through a request-response interaction mechanism.

[0067] FIG. 2 is a schematic diagram of a unicast connection establishment process according to an embodiment of the present application. As shown in FIG. 2, the process includes the following steps.

[0068] S201. The initiating UE sends a direct communication request (DCR) message to the target UE. Correspondingly, the target UE receives the DCR message from the initiating UE.

[0069] The DCR message includes an L2 ID of the initiating UE (that is, a source L2 ID), an L2 ID of the target UE (that is, a destination L2 ID), and user information. The user information includes related information of an upper application layer, which is not described herein.

[0070] S202. The target UE sends a direct communication accept (DCA) message to the initiating UE. Correspondingly, the initiating UE receives the DCA message from the target UE.

[0071] It can be understood that after receiving the DCR message, the target UE can determine whether to accept the direct communication request according to the user information included in the DCR message, and if so, the target UE sends a DCA message to the initiating UE, and then establishes a unicast connection.

[0072] In addition, if not accepted, the target UE performs step S203 to inform the initiating UE of the rejection of establishing a unicast connection.

[0073] S203, the target UE sends a direct communication rejection message to the initiating UE. Accordingly, the initiating UE receives the direct communication rejection message from the target UE.

[0074] The direct communication rejection message is used to indicate the rejection of the DCR.

[0075] It can be understood that after establishing a unicast connection, data transmission can be performed between the initiating UE and the target UE.

[0076] In addition, the initiating UE can achieve data transmission between the initiating UE and the network device through the target UE, which will be described in detail below.

[0077] Second, SL UE-to-network relay (UE-to-network relay, SL U2N relay) technology:

[0078] SL U2N relay technology is a technology in which one UE helps another UE to communicate with a network device. The UE that helps another UE to communicate with a network device can be a relay UE, and the other UE can be called a remote UE.

[0079] The following exemplary describes the communication architecture of SL U2N relay taking the network device as a next generation NodeB (gNB) in a 5th generation (5G) mobile communication system (such as a new radio (NR) system).

[0080] FIG. 3 is a schematic diagram of a communication architecture of SL U2N relay provided by an embodiment of the present application. As shown in FIG. 3, the remote UE can communicate with the gNB through the cooperation of the relay UE. The remote UE and the relay UE communicate through SL, and the corresponding interface is PC5. The SL can also be referred to as a PC5 link. The relay UE is directly connected to the gNB, and the relay UE can communicate with the gNB through Uu. The wireless link between the relay UE and the gNB can be referred to as a Uu link.

[0081] Currently, the SL U2N relay technology mainly includes L2 relay and L3 relay. Among them, the L2 relay can refer to: the data packet of the remote UE is relayed and forwarded below the PDCP layer of the relay UE, that is, the relay UE only maintains a relay RLC bearer including the RLC layer, the MAC layer, and the PHY layer. That is, for the user plane protocol stack, there are end-to-end PDCP layers and SDAP layers between the remote UE and the gNB; for the control plane protocol stack, there are end-to-end PDCP layers, SDAP layers, and RRC layers between the remote UE and the gNB.

[0082] In addition, in order to support different end-to-end wireless bearers that can be multiplexed on one RLC bearer, and corresponding demultiplexing, a sidelink relay adaptation protocol layer (SRAP) is added between the RLC layer and the PDCP layer to provide multiplexing and demultiplexing services for wireless bearers. It can be understood that the RLC bearer between the remote UE and the relay UE can be referred to as a PC5 relay RLC channel or bearer, and the RLC bearer between the relay UE and the gNB can be referred to as a Uu relay RLC channel or bearer. The above-mentioned multiplexing can refer to: different wireless bearers of one remote UE can be multiplexed on one PC5 relay RLC channel; or in the scenario where one relay UE connects multiple remote UEs (i.e., one relay UE provides relay services for multiple remote UEs), different wireless bearers of one or more remote UEs can be multiplexed on one Uu relay RLC channel.

[0083] Figure 4 is a schematic diagram of a protocol stack structure of an L2 U2N relay provided by an embodiment of the present application. As shown in (a) of Figure 4, for the user plane protocol stack structure of the L2 U2N relay, the protocol stack of the remote UE includes, from top to bottom: a Uu-SDAP layer, a Uu-PDCP layer, a PC5-SRAP layer, a PC5-RLC, a PC5-MAC, and a PC5-PHY. The protocol stack of the relay UE relative to the remote UE side includes, from top to bottom: a PC5-SRAP layer, a PC5-RLC, a PC5-MAC, and a PC5-PHY. The protocol stack of the relay UE relative to the gNB side includes, from top to bottom: a Uu-SRAP layer, a Uu-RLC, a Uu-MAC, and a Uu-PHY. The protocol stack of the gNB includes, from top to bottom: a Uu-SDAP layer, a Uu-PDCP layer, a Uu-SRAP layer, a Uu-RLC, a Uu-MAC, and a Uu-PHY.

[0084] As shown in (b) of FIG. 4, for the control plane protocol stack structure of the L2 U2N relay, the difference between the user plane protocol stack structure of (a) of FIG. 4 is that the Uu-SDAP layer between the Uu-PDCP layer between the remote UE and the gNB is replaced by the Uu-RRC layer.

[0085] It can be understood that data transmission can be performed only after the RRC connection is established between the UE and the gNB, and then the above-mentioned data transmission between the remote UE and the gNB is also applied after the RRC connection is established. The establishment (setup), reestablishment, and resume of the RRC connection are specifically introduced below.

[0086] Third: the RRC connection setup, reestablishment, or resume procedure:

[0087] It can be understood that in the NR system, there are three RRC states of the UE, which are as follows:

[0088] a, the RRC connected state, that is, the UE establishes the RRC connection with the network, and data transmission can be performed between the UE and the network;

[0089] b, the RRC idle state, that is, the UE does not establish the RRC connection with the network, and the gNB does not have the context of the UE. If the UE needs to enter the RRC connected state from the RRC idle state, the RRC connection setup (RRC setup) procedure needs to be initiated;

[0090] c, the inactive state, which can mean that after the UE enters the RRC connected state, the gNB releases the RRC connection of the UE, and the gNB saves the context of the UE. If the UE needs to enter the RRC connected state from the RRC inactive state, the RRC connection resume (RRC resume) procedure needs to be initiated.

[0091] It can be understood that the RRC connection resume procedure has shorter latency and smaller signaling overhead than the RRC setup procedure, but the gNB needs to retain the context of the UE.

[0092] In addition, the RRC reestablishment procedure is mainly used to handle the case that the RRC connection is interrupted due to mobility management or underlying link failure, etc., and aims to quickly recover the interrupted RRC connection to guarantee the communication experience of the user. It can be understood that the factors causing the interruption of the RRC connection may include, for example, radio link failure (RLF), handover failure, or the maximum number of RLC retransmissions.

[0093] The RRC connection establishment procedure, the RRC connection reestablishment procedure, and the RRC connection resume procedure are introduced below respectively.

[0094] 3.1. RRC connection establishment procedure

[0095] FIG. 5 is a schematic diagram of an RRC establishment procedure according to an embodiment of the present application. As shown in FIG. 5, the procedure includes the following steps.

[0096] S501. The UE sends an RRC setup request message to the network. Accordingly, the network receives the RRC setup request message from the UE.

[0097] The RRC setup request message is used to request establishment of an RRC connection.

[0098] S502. The network sends an RRC setup message to the UE. Accordingly, the UE receives the RRC setup message from the network.

[0099] The RRC setup message includes parameters for establishing radio bearers. It can be understood that the UE establishes radio bearers according to the RRC setup message, and after entering the RRC connected state, can send an RRC setup complete message to the network to indicate that the RRC connection establishment is complete.

[0100] S503. The UE sends an RRC setup complete message to the network. Accordingly, the network receives the RRC setup complete message from the UE.

[0101] 3.2. RRC connection reestablishment procedure

[0102] FIG. 6 is a schematic diagram of an RRC connection reestablishment procedure according to an embodiment of the present application. As shown in FIG. 6, the procedure includes the following steps.

[0103] S601. The UE sends an RRC reestablishment request message to the network. Accordingly, the network receives the RRC reestablishment request message from the UE.

[0104] The RRC reestablishment request message is used to request reestablishment of the RRC connection of the UE, and the RRC reestablishment request message can include a reestablishment cause and a context of the UE.

[0105] S602. The network sends an RRC reestablishment message to the UE. Accordingly, the UE receives the RRC reestablishment message from the network.

[0106] The RRC reestablishment message includes parameters for reestablishing a radio bearer. It can be understood that after receiving the RRC reestablishment request message, the network side can verify the security of the UE and authenticate whether the UE has the right to communicate. If the authentication is successful, the network side sends the RRC reestablishment message to the UE.

[0107] In addition, after receiving the RRC reestablishment message, the UE establishes a radio bearer according to the RRC reestablishment message, and after re-entering the RRC connected state, the UE can send an RRC reestablishment complete message to the network to indicate that the RRC connection reestablishment is complete.

[0108] S603, the UE sends an RRC reestablishment complete message to the network. Correspondingly, the network receives the RRC reestablishment complete message from the UE.

[0109] 3.3, RRC connection recovery process:

[0110] FIG. 7 is a flowchart of an RRC connection recovery process provided by an embodiment of the present application. As shown in FIG. 7, the process includes:

[0111] S701, the UE sends an RRC resume request message to the network. Correspondingly, the network receives the RRC resume request message from the UE.

[0112] The RRC resume request message is used to request to resume the RRC connection of the UE.

[0113] In addition, the RRC resume request message can also be replaced by an RRC resume request 1 message. The main difference between the two is that the two carry different resume IDs.

[0114] S702, the network sends an RRC resume message to the UE. Correspondingly, the UE receives the RRC resume message from the network.

[0115] It can be understood that the UE resumes a radio bearer according to the RRC resume message, and after entering the RRC connected state, the UE can send an RRC resume complete message to the network to indicate that the RRC resume is complete.

[0116] S703, the UE sends an RRC resume complete message to the network. Correspondingly, the network receives the RRC resume complete message from the UE.

[0117] It should be understood that in any of the above flowcharts of FIG. 5-7, when the UE triggers to send a first RRC message (e.g., RRC setup request, RRC reestablishment request, or RRC resume request), a timer corresponding to the RRC message will be triggered to start. The timer for RRC connection setup (T300), the timer for RRC connection reestablishment (T301), and the timer for RRC connection resume (T319) can be specifically referred to the description of Table 1.

[0118] Table 1

[0119] It can be understood that the UE can be directly connected with the network through a Uu link, or can be connected with the network through a relay UE. In these two cases, the duration of the above timer (T300 or T301 or T319) is different, which will be described below.

[0120] For the UE directly connected with the network through a Uu link, the UE can obtain the configuration of T300, the configuration of T301, and the configuration of T319 by receiving SIB1. For example, the duration t300 of T300 can be [100 milliseconds (ms), 200 ms, 300 ms, 400 ms, 600 ms, 1000 ms, 1500 ms, 2000 ms]. For another example, the duration t301 of T301 can be [100 ms, 200 ms, 300 ms, 400 ms, 600 ms, 1000 ms, 1500 ms, 2000 ms]. For another example, the duration t319 of T319 can be [100 ms, 200 ms, 300 ms, 400 ms, 600 ms, 1000 ms, 1500 ms, 2000 ms].

[0121] For the case that the remote UE connects to the network through the relay UE, the T300 in this case is referred to as T300-RemoteUE-r17, the T301 is referred to as T301-RemoteUE-r17, and the T319 is referred to as T319-RemoteUE-r17. Among them, the remote UE can obtain the configuration of T300-RemoteUE-r17, the configuration of T301-RemoteUE-r17, and the configuration of T319-RemoteUE-r17 through SIB12. For example, the time length t300-RemoteUE-r17 of T300-RemoteUE-r17 can be [100ms, 200ms, 300ms, 400ms, 600ms, 1000ms, 1500ms, 2000ms]. For another example, the time length t301-RemoteUE-r17 of T301 can be [100ms, 200ms, 300ms, 400ms, 600ms, 1000ms, 1500ms, 2000ms]. For another example, the time length t319-RemoteUE-r17 of T319 can be [100ms, 200ms, 300ms, 400ms, 600ms, 1000ms, 1500ms, 2000ms].

[0122] It should be understood that, as shown in FIG. 3, the link through which the remote UE connects to the gNB through the relay UE specifically includes two-hop links: the PC5 link between the remote UE and the relay UE, and the Uu link between the relay UE and the gNB, and thus the value of T300-RemoteUE-r17 in SIB12 is greater than the value of T300 in SIB1, and similarly, the value of T301-RemoteUE-r17 is greater than the value of T301, and the value of T319-RemoteUE-r17 is greater than the value of T319.

[0123] Fourth, SL multi-hop relay technology:

[0124] As an evolution of the SL U2N relay technology, the remote UE can connect to the network through multiple relay UEs, that is, the relay UE can connect to the network through other relay UEs.

[0125] FIG. 8 is a schematic diagram of a communication architecture of SL multi-hop relay provided by an embodiment of the present application. As shown in FIG. 8, the remote UE connects to the relay UE#2 through the relay UE#1, and the relay UE#2 directly connects to the gNB, that is, the remote UE connects to the gNB through the relay UE#1 and the relay UE#2.

[0126] It can be understood that in FIG. 8, the link through which the remote UE connects with the gNB by the relay UE specifically includes a three-hop link: a PC5 link between the remote UE and the relay UE #1, a PC5 link between the relay UE #1 and the relay UE #2, and a Uu link between the relay UE #2 and the gNB.

[0127] However, the above-mentioned related description about T300-RemoteUE-r17, T301-RemoteUE-r17, and T319-RemoteUE-r17 in SIB12 is applicable to the two-hop link scenario shown in FIG. 3, and if the timers in SIB12 are used in the three-hop link scenario shown in FIG. 8, it will cause the RRC connection to be incorrectly interrupted.

[0128] For example, in FIG. 8, since the link between the remote UE and the gNB is a three-hop link, which is longer than the two-hop link in FIG. 3, and then the duration of the timer in SIB12 is too small, the remote UE may not have received the RRC message, and the timer in SIB12 may have timed out, thereby causing the RRC connection to be incorrectly interrupted.

[0129] Based on the above description, how the remote UE determines the duration of the timer for RRC connection establishment or re-establishment or recovery in the SL multi-hop relay scenario is a problem that needs to be solved urgently at present.

[0130] In view of the above technical problems, the embodiments of the present application provide the following technical solutions. The technical solutions in the present application will be described below with reference to the drawings.

[0131] The present application will present various aspects, embodiments or features around a system that can include a plurality of devices, components, modules, etc. It should be understood and appreciated that each system can include additional devices, components, modules, etc., and / or can not include all of the devices, components, modules, etc. discussed in connection with the drawings. In addition, combinations of these solutions can also be used.

[0132] To facilitate understanding of the solutions provided by the embodiments of the present application, the following points are first explained.

[0133] 1. In the embodiments of the present application, the words such as "example", "for example", etc. are used to represent an example, illustration or description. Any embodiment or design scheme described as "example" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the word "example" is intended to present the concept in a specific way.

[0134] 2. In this application, “for indicating” can include for directly indicating and for indirectly indicating. When describing that a certain “information” is for indicating A, it can include that the information directly indicates A or indirectly indicates A, and does not mean that A must be carried in the information.

[0135] The information indicated by one information is referred to as to-be-indicated information. In the implementation process, there are many ways to indicate the to-be-indicated information, for example, but not limited to, the to-be-indicated information can be directly indicated, such as the to-be-indicated information itself or an index of the to-be-indicated information. The to-be-indicated information can also be indirectly indicated by indicating other information, where the other information and the to-be-indicated information have an association relationship. The to-be-indicated information can also be only indicated in part, and the other part of the to-be-indicated information is known or agreed in advance. For example, the indication of a specific information can also be achieved by means of the arrangement order of each information agreed in advance (for example, specified by a protocol), thereby reducing the indication overhead to a certain extent. At the same time, the common part of each information can be identified and uniformly indicated, so as to reduce the indication overhead caused by separately indicating the same information.

[0136] In addition, the specific indication manner can also be various existing indication manners, for example, but not limited to, the above-mentioned indication manners and various combinations thereof. The specific details of various indication manners can refer to the prior art, and will not be described herein. As can be seen from the above, for example, when multiple information of the same type needs to be indicated, the indication manners of different information can be different. In the implementation process, the required indication manner can be selected according to the specific needs, and the selected indication manner is not limited by the embodiments of the present application. In this way, the indication manner involved in the embodiments of the present application should be understood as covering various methods that can enable the to-be-indicated party to know the to-be-indicated information.

[0137] The to-be-indicated information can be sent as a whole, or can be divided into multiple sub-information and sent separately, and the sending period and / or sending occasion of the sub-information can be the same or different. The specific sending method is not limited by the present application. The sending period and / or sending occasion of the sub-information can be pre-defined, for example, pre-defined according to a protocol, or configured by the transmitting end device by sending configuration information to the receiving end device. The configuration information can include, for example, but not limited to, one of RRC signaling, MAC layer signaling and physical layer signaling, or a combination of at least two of them. The MAC layer signaling includes, for example, a MAC control element (CE), and the physical (PHY) layer signaling includes, for example, control information (CI).

[0138] 3、In the embodiments shown below, the first, second and various numbers are only for the convenience of differentiation, and do not limit the scope of the embodiments of the application. For example, different indication information is distinguished.

[0139] 4、"preset" or "predefined" or "preconfigured" can be realized by pre-saving corresponding codes, tables or other ways that can be used to indicate related information in devices (for example, including terminal devices and network devices), and can also be pre-provided in a protocol. The specific implementation manner is not limited in the application. Wherein, "saving" can mean saving in one or more memories. The one or more memories can be separately set, or can be integrated in the encoder or decoder, processor, or communication device. The one or more memories can also be part of separate setting, and part of integration in the decoder, processor, or communication device. The type of memory can be any form of storage medium, which is not limited in the application.

[0140] 5、The "protocol" involved in the embodiments of the application can refer to a protocol family in the communication field, a standard protocol similar to the protocol family frame structure, or a related protocol applied to a future communication system, which is not limited in the embodiments of the application.

[0141] 6、In the embodiments of the application, "when", "in the case of", "if" and other descriptions all refer to that the device will make corresponding processing under certain objective conditions, not limited to time, and also does not require the device to have a judgment action when implemented, nor means that there are other limitations.

[0142] 7、The technical solutions of the embodiments of the application can be applied to various communication systems, for example, a vehicle to everything (V2X) communication system, a device-to-device (D2D) communication system, a vehicle networking communication system, a 4th generation (4G) mobile communication system (such as a long term evolution (LTE) system), a worldwide interoperability for microwave access (WiMAX) communication system, a 5th generation (5G) mobile communication system (such as a new radio (NR) system), a future communication system, or a wireless fidelity (Wi-Fi) system.

[0143] 8、The network architecture and service scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of network architecture and the appearance of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0144] To facilitate understanding of the embodiments of the present application, first, a communication system shown in FIG. 9 is taken as an example to be described in detail, which is applicable to the embodiments of the present application.

[0145] FIG. 9 is a schematic diagram of the architecture of a possible, non-limiting communication system provided by the embodiments of the present application. As shown in FIG. 9, the communication system mainly includes a first terminal, a second terminal, and a network device.

[0146] Optionally, the second terminal can connect the network device through one or more terminals, for example, the second terminal can also connect the network device through a third terminal, a fourth terminal, or an Mth terminal, where M is an integer greater than 5.

[0147] It can be understood that the first terminal, the second terminal, and other terminals (for example, the third terminal, the fourth terminal, or the Mth terminal in FIG. 9) all belong to terminals, that is, devices or modules with corresponding communication functions that access the network device. The terminal can also be referred to as a terminal device, UE, mobile station, or mobile terminal, etc. The terminal can be widely applied to various scenarios, for example, device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), internet of things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, remote medical treatment, smart grid, smart furniture, smart office, smart wear, smart transportation, or smart city, etc. The terminal can specifically be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, a transport vehicle with wireless communication function, or a communication module, etc. The embodiments of the present application do not limit the device form of the terminal. The terminal is usually provided with a communication module, circuit or chip for executing corresponding communication functions. The terminal is also configured with program instructions for executing corresponding communication functions.

[0148] It can be understood that the first terminal can be a terminal supporting connecting a network device through a relay service. For example, the first terminal can be a remote UE in FIGS. 3-4, or a communication module in the remote UE, or a circuit or chip responsible for communication functions in the remote UE (such as a modem chip, also known as a baseband chip, or a system on chip (SoC) chip or system in package (SIP) chip containing a modem core).

[0149] It can also be understood that the second terminal can be a terminal supporting providing a relay service. For example, the second terminal can be a relay UE in FIGS. 3-4, or a communication module in the relay UE, or a circuit or chip responsible for communication functions in the relay UE (such as a modem chip, also known as a baseband chip, or a system on chip (SoC) chip or system in package (SIP) chip containing a modem core).

[0150] In addition, the second terminal can also support connecting a network device through a relay service, that is, the second terminal can connect a network device through other terminals (such as a third terminal, or a fourth terminal, etc.) in FIG. 9. For example, the second terminal can also be a relay UE#1 in FIG. 8.

[0151] It should be understood that the other terminal can be a terminal supporting providing a relay service, which can be a relay UE in FIGS. 3-4.

[0152] In addition, with the evolution of the network, the first terminal or the second terminal can also use other names, which are not limited in the embodiments of the present application.

[0153] The network device can be a device providing access service functions, such as a radio access network (RAN) node. The RAN node can be a 3GPP related cellular communication system, for example, a 4G, 5G mobile communication system, or a future-oriented evolution system. The RAN node can also be an open access network (open RAN, O-RAN or ORAN), a cloud radio access network (CRAN), or a Wi-Fi system. The RAN node can also be a communication system that combines two or more of the above systems. The RAN node can also be referred to as an access network device, a RAN entity, or an access node, etc., which constitutes part of a communication system to help terminals realize wireless access. Multiple RAN nodes in a communication system can be nodes of the same type or nodes of different types.

[0154] In a possible scenario, the RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next generation NodeB (gNB), a base station in a future mobile communication system, or an access node in a Wi-Fi system, etc. The RAN node can be a macro base station, a micro base station or an indoor station, a relay node or a donor node, or a wireless controller in a CRAN scenario. Optionally, the RAN node can also be a server, a wearable device, a vehicle or a vehicle-mounted device, etc. For example, the access network device in vehicle to everything (V2X) technology can be a road side unit (RSU). All or part of the functions of the RAN node in the present application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform such as a cloud platform. The RAN node can also be provided with a communication module, circuit or chip for performing corresponding communication functions, and program instructions for performing corresponding communication functions. The RAN node in the present application can also be a logical node, a logical module or software that can implement all or part of the functions of the RAN node.

[0155] In another possible scenario, multiple RAN nodes cooperate to assist a terminal to implement wireless access, and different RAN nodes respectively implement part of the functions of a base station. For example, the RAN node can be a central unit (CU), a distributed unit (DU) or a radio unit (RU), etc. In some examples, the CU is a logical node carrying the RRC layer, the SDAP layer, the PDCP layer, the SRAP layer and other control functions of the access network device. The CU is connected to network nodes such as core network through some interfaces, which can be E2 interface and the like. Optionally, the CU can have part of the functions of the core network. The CU (such as the PDCP layer and higher layers) is connected to the DU (such as the RLC layer and lower layers) through some interfaces, which can be F1 interface and the like.

[0156] In some examples, the CU can be split into a CU-CP (control unit-control plane) and a CU-UP (control unit-user plane), where the CU-CP is a logical node carrying the RRC layer and the PDCP-C (control plane part of PDCP) layer, and is used to implement the control plane function of the CU.

[0157] In different systems, the CU (or CU-CP and CU-UP), DU or RU can also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, the CU can also be referred to as O-CU (open CU), the DU can also be referred to as O-DU, the CU-CP can also be referred to as O-CU-CP, the CU-UP can also be referred to as O-CU-UP, and the RU can also be referred to as O-RU. For the convenience of description, the CU, CU-CP, CU-UP, DU and RU are taken as examples for description in this application. Any one of the CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0158] For the problem of how a remote UE determines the length of a timer for RRC connection establishment or re-establishment or recovery in a scenario where there is SL multi-hop relaying, the communication system shown in FIG. 9 provides the following solution.

[0159] In a possible implementation, the first terminal receives first indication information from the second terminal, the first indication information being information for determining a first hop number of the first link, the first hop number being associated with a number of network devices and / or terminals on the first link, the first link being a wireless link through which the first terminal connects to the network device via the second terminal; and the first terminal determines the length of the first timer according to the first hop number information, the length of the first timer being a length corresponding to the first link.

[0160] In the embodiments of the present application, the first terminal can determine the first hop number information of the first link through which the first terminal connects to the network device via the second terminal through the first indication information from the second terminal, and further determine the length of the first timer suitable for establishing a connection with the network device on the first link according to the first hop number information of the first link.

[0161] The above method provided by the embodiments of the present application will be described below in conjunction with FIG. 10.

[0162] It should be understood that the names of signals, parameters in signals, or information carried by signals between various devices or apparatuses in the following embodiments of the present application, or the like, are only examples, and other names can also be used in actual implementation, which is not limited by the embodiments of the present application.

[0163] It can be understood that the method provided by the embodiments of the present application can be applied to the first terminal and the second terminal, and also applied to the modules or units (for example, a chip, a chip system, a chip circuit, or a circuit, etc.) in the first terminal and the modules or units in the second terminal, which is not limited by the embodiments of the present application.

[0164] For the convenience of understanding, the following takes the interaction between the first terminal and the second terminal as an example to describe the scheme provided by the system shown in FIG. 9 in detail.

[0165] FIG. 10 is a flow diagram of a communication method provided by an embodiment of the present application. As shown in FIG. 10, the method comprises the following steps:

[0166] S1001, the second terminal sends first indication information to the first terminal. Correspondingly, the first terminal receives the first indication information from the second terminal. The first indication information is information for determining a first hop count of the first link. The first hop count is associated with the number of network devices and / or terminals on the first link. The first link is a wireless link through which the first terminal connects the network device via the second terminal.

[0167] S1002, the first terminal determines the duration of the first timer according to the information of the first hop count. The duration of the first timer is the duration corresponding to the first link.

[0168] The steps S1001 and S1002 are described below.

[0169] For step S1001:

[0170] It can be understood that the first hop count is associated with the number of terminals and / or network devices on the first link. The first link is introduced first, and then the first hop count is introduced, and finally the information of the first hop count is introduced.

[0171] A. The first link:

[0172] It can be understood that the first link is a wireless link through which the first terminal connects the network device via the second terminal, that is, the first link can be specifically divided into: a wireless link between the first terminal and the second terminal, and a wireless link between the second terminal and the network device.

[0173] For the wireless link between the first terminal and the second terminal, the first terminal can be a remote UE, and the second terminal can be a relay UE. The connection between the first terminal and the second terminal can be a direct connection. The direct connection can mean that the first terminal is connected to the second terminal through PC5, and the wireless link between the first terminal and the second terminal is a direct connection link (for example, a PC5 link) between terminals. For example, the PC5 link between the remote UE and the relay UE in FIG. 4. In addition, the direct connection can also mean that the first terminal can be connected to the second terminal through Bluetooth or Wi-Fi technology, and the embodiments of the present application do not make specific limitations.

[0174] It should be understood that, in the case where it is not explicitly indicated that the direct connection link between terminals is different from the PC5 link, the two can be expressed as each other, which is uniformly described here, and the following will not be repeated.

[0175] It can be understood that the first terminal and the second terminal can also be connected to other terminals, for example, the first terminal can be connected to the second terminal through other terminals, and the embodiments of the present application do not make specific limitations.

[0176] In addition, for the first terminal sending the first indication information to the second terminal, it can be understood that the destination of the first indication information is the first terminal, which can include the second terminal directly or indirectly sending the first indication information to the first terminal. The first terminal receives the indication information from the second terminal, which can be understood as the source of the first indication information is the second terminal, which can include the first terminal directly or indirectly receiving the first information from the second terminal. The first indication information can be processed between the source and the destination, for example, format change, etc., but the destination can understand the effective information from the source. Similar expressions in this application can be understood similarly, and will not be repeated here.

[0177] For the wireless link between the second terminal and the network device, the second terminal can be directly connected to the network device, and the second terminal and the network device can also be connected through one or more relays, that is, the number of nodes between the second terminal and the network device is greater than 2, and the second terminal and the network device can include at least one PC5 link and one Uu link.

[0178] Based on the above description of the first terminal connecting to the network device through the second terminal, the first link can include at least one PC5 link and one Uu link.

[0179] B, the first hop number:

[0180] In a possible implementation, the first hop number can refer to the number of terminals on the first link, or the number of links (i.e., PC5 links) directly connecting the terminals on the first link. For example, if the number of terminals (including the first terminal) on the first link is N, then the number of PC5 links on the first link is N-1, and the first hop number is N-1, where N is an integer greater than or equal to 1.

[0181] In another possible implementation, the first hop number can refer to the sum of the number of terminals on the first link and the number of network devices, or the sum of the number of links (i.e., PC5 links) directly connecting the terminals on the first link and the number of links (i.e., Uu links) directly connecting the terminals on the first link to the network devices.

[0182] For example, assuming that the number of terminals on the first link is N and the number of network devices is 1 (usually one network device), the first hop number is N, the number of PC5 links on the first link is N-1, and the number of Uu links on the first link is 1.

[0183] In addition, assuming that the number of network devices M on the first link is an integer greater than 1, the first hop number is N+M.

[0184] C. Information of the first hop number:

[0185] It can be understood that the information of the first hop number can include at least one of the following: the number of terminals on the first link, the number of network devices on the first link, the number of terminals other than the first terminal on the first link (i.e., the number of terminals providing relay services, or the number of relay terminals), the number of links directly connecting the terminals on the first link, the number of links directly connecting the terminals on the first link to the network devices, or information of the second hop number of the second terminal connecting to the network device.

[0186] Optionally, the information of the second hop number of the second terminal connecting to the network device can include at least one of the following: the number of terminals on the wireless link between the second terminal and the network device, the number of network devices, the number of terminals other than the second terminal, the number of links directly connecting the terminals, or the number of links directly connecting the terminals to the network devices.

[0187] In addition, the information of the first hop number can indicate a range (or called a gear) in which the first hop number is located. For example, according to whether the first terminal connects the network device through another terminal in addition to the second terminal, two gears can be divided: one gear indicates that the first terminal connects the network device through only the second terminal, and the other gear indicates that the first terminal connects the network device through another terminal in addition to the second terminal. It can be understood that if the first terminal connects the network device through only the second terminal, the first link includes 2 terminals, 1 PC5 link, 1 relay terminal, and 1 Uu link, and then the first hop number can be 1 (that is, 1 PC5 link and 1 relay terminal) or the first hop number can be 2 (that is, 2 terminals, 1 PC5 link, and 1 Uu link).

[0188] If the first terminal connects the network device through another terminal in addition to the second terminal, it can be determined that the first hop number is greater than 1 (the number of PC5 links on the first link is greater than 1, or the number of relay terminals is greater than 1, etc.), or the first hop number is greater than 2 (that is, the sum of the number of PC5 links and the number of Uu links on the first link is greater than 2).

[0189] Alternatively, the gears can be further subdivided, for example, for the first hop number being the number N of PC5 links on the first link being greater than 1, N being [2, 3] can be divided into a gear, and N being [4, 5, 6] can be divided into a gear, and the embodiments of the present application do not make specific limitations.

[0190] It can be understood that by dividing the gears, the first hop numbers belonging to the same gear can be executed by the same strategy in step S1002.

[0191] The first indication information will be introduced below.

[0192] In a possible implementation, the first indication information indicates information of a second hop number of the second terminal connecting the network device, and the second hop number is associated with the number of terminals on a wireless link of the second terminal connecting the network device; or the first indication information is an identifier of a relay service provided by the second terminal.

[0193] It can be understood that the second hop number is similar to the definition of the first hop number, and the second hop number can be the number of terminals on a wireless link of the second terminal connecting the network device, or the number of PC5 links, etc., and specific can be referred to the related description of the first hop number, which will not be repeated here.

[0194] In a possible implementation, the information of the second hop number is used to determine the information of the first hop number.

[0195] It can be understood that, since the first link comprises a wireless link of the second terminal connecting the network device, the first hop information can be determined by the second hop information. For example, the first hop information can be determined by the second hop information and the wireless link between the first terminal and the second terminal. For example, assuming that the first terminal and the second terminal are directly connected, the first hop is actually the second hop plus 1. For another example, assuming that the first terminal is connected with the second terminal through a third terminal, the wireless link between the first terminal and the second terminal can comprise two PC5 links, and the first hop is actually the second hop plus 2.

[0196] It can also be understood that, by the identifier used for indicating the relay service provided by the second terminal, the type of the relay service provided by the second terminal can be determined, and then it can be determined whether the second terminal is directly connected with the network device, and then the first hop information can be determined. For example, the identifier used for indicating the relay service provided by the second terminal can be a relay service code (RSC), or other identifier used for indicating the relay service provided by the second terminal, and the embodiments of the present application do not make specific limitation thereto.

[0197] It can be understood that the first indication information can be transmitted before the second terminal establishes a connection with the first terminal, or can be transmitted after the establishment.

[0198] For example, the first indication information can be transmitted by a discovery message broadcast by the second terminal before the second terminal establishes a connection with the first terminal. For another example, the second terminal can send the first indication information directly to the first terminal after the second terminal establishes a connection with the first terminal.

[0199] For step S1002:

[0200] In a possible implementation, the first timer is applied to a radio resource control (RRC) connection establishment procedure, or a re-establishment procedure, or a resume procedure.

[0201] It can be understood that the first timer is similar to the timers T300, T301 and T319 in the foregoing Table 1, and is specifically used for the RRC connection establishment procedure, or the re-establishment procedure, or the resume procedure of the first terminal. For details, refer to the “RRC connection establishment, re-establishment or resume procedure” in the preceding part of the specific embodiments, which will not be described here again.

[0202] In a possible implementation, the duration of the first timer is associated with at least one of the following durations:

[0203] a first duration, the first duration being a duration corresponding to a directly connected link pair between terminals on the first link;

[0204] a second time length, the second time length being a time length corresponding to the terminal directly connecting the network device;

[0205] or a third time length, the third time length being a time length corresponding to the terminal connecting the network device through a relay.

[0206] It can be understood that the time length of the first timer is in a proportional relationship with the first time length, that is, the longer the first time length, the longer the time length of the first timer. In addition, the time length of the first timer is also in a proportional relationship with the first hop number, that is, the greater the first hop number, the longer the time length of the first timer.

[0207] For example, assuming that the first hop number is the number of links directly connected between terminals on the first link (or the number of terminals providing relay services on the first link), the time length of the first timer is in a proportional relationship with the number.

[0208] In addition, the first time length can refer to the time length part corresponding to the link (i.e., the PC5 link) directly connected between terminals in the time length of the first timer when the first terminal performs the RRC connection establishment process, or the re-establishment process, or the recovery process.

[0209] It should be understood that for the second time length, the second time length can refer to the time length corresponding to the RRC connection establishment process, or the re-establishment process, or the recovery process when the terminal directly connects with the network device (i.e., the terminal accesses the network device through the Uu, or connects the network device through the Uu link) or the terminal establishes the RRC related connection on the Uu. Alternatively, the second time length can also be understood as the time length of the second timer, the second timer being a timer for the terminal to establish a connection with the network device through the Uu interface or link, for example, the second timer can be used for the RRC connection establishment process, or the re-establishment process, or the recovery process when the terminal accesses the network device through the Uu interface or link.

[0210] For example, the second timer can be the value of T300 configured by SIB1 in the aforementioned “RRC connection establishment, re-establishment, or recovery process”, or the value of T301, or the value of T319.

[0211] It can be understood that for the third time length, the third time length can refer to the time length corresponding to the terminal connecting the network device through a relay. Alternatively, the third time length can also be understood as the time length corresponding to the terminal connecting the network device through a relay service. Alternatively, the third time length can also be understood as the time length used by the terminal connecting the network device through a relay to perform the RRC connection establishment process, the re-establishment process, or the recovery process. Alternatively, the third time length can also be understood as the time length of the third timer, the third timer being a timer for the terminal to establish a connection with the network device through a relay, for example, the third timer can be used for the RRC connection establishment process, or the re-establishment process, or the recovery process when the terminal accesses the network device through a relay terminal.

[0212] For example, the third timer can be a value of T300-RemoteUE-r17 configured by SIB1 in the aforementioned "RRC connection establishment, re-establishment, or resume procedure", or a value of T301-RemoteUE-r17, or a value of T319-RemoteUE-r17.

[0213] It should be understood that the duration of the first timer can be determined according to at least one of the aforementioned first duration, second duration, or third duration, which will be specifically explained below.

[0214] In a possible implementation, the first terminal determines the duration of the first timer according to the information of the first hop number, including: the first terminal determines the duration of the first timer according to the information of the first hop number and the first duration, and the first duration is a duration corresponding to a link directly connecting terminals on the first link.

[0215] That is, the first terminal can determine the duration of the first timer suitable for establishing a connection with the network device on the first link according to the information of the first hop number and the first duration corresponding to establishing a connection on the link directly connecting the terminals on the first link, so that the first terminal can receive the message for establishing a connection transmitted by the network device, and avoid mistakenly interrupting the connection.

[0216] For example, considering that the first duration corresponding to the link directly connecting the terminals can be less than or equal to the second duration corresponding to the terminal directly connecting the network device, the second duration can be represented by T times the first duration, and T can be an integer greater than or equal to 1. Assuming that the first hop number is the number N of links directly connecting the terminals on the first link, the duration of the first timer can be N+1 times the first duration, or N+2 times the first duration, or N+3 times the first duration, which is not limited in the embodiments of the present application.

[0217] In a possible implementation, the first duration is indicated by the network device; or the first duration is determined according to the second duration and the third duration, the second duration being a duration corresponding to the terminal directly connecting the network device, and the third duration being a duration corresponding to the terminal connecting the network device through a relay.

[0218] That is, for the first duration indicated by the network device, the first terminal can determine the duration of the first timer based on the indicated first duration and the information of the first hop number, thereby reducing the complexity of the first terminal in determining the duration of the first timer. In addition, the first terminal can also determine the first duration according to the second duration and the third duration, which can participate in the flexibility of determining the first duration.

[0219] It can be understood that, in a case that the second time length is a time length of a timer configured by the network device through the SIB1, and the third time length is a time length of a timer configured through the SIB12, the first time length is determined through the second time length and the third time length, the change to the network side is small, and the deployment is easy.

[0220] It can also be understood that, for the first time length being indicated by the network device, the network device can configure the first time length through the SIB, for example, being indicated in the SIB12 or other SIBs, and the embodiments of the present application do not make a specific limitation in this regard.

[0221] In a possible implementation, the first time length is determined according to the second time length and the third time length, including that the first time length is a difference between the second time length and the third time length.

[0222] That is, the first terminal can obtain the first time length by subtracting the second time length from the third time length, and the complexity of determining the first time length on the first terminal side can be reduced.

[0223] It should be understood that the above-mentioned first time length being a difference between the second time length and the third time length is only an example, and can also be an offset of the difference between the second time length and the third time length, and the embodiments of the present application do not make a specific limitation in this regard.

[0224] In addition, the first time length can also be determined according to the third time length, for example, the first time length can be 1 / 2, 1 / 3, or 1 / 4 of the third time length, and the embodiments of the present application do not make a specific limitation in this regard.

[0225] In a possible implementation, the first time length is determined according to the second time length and the third time length; the first terminal determines the time length of the first timer according to the information of the first hop number and the first time length, including that the first terminal determines the time length of the first timer according to the information of the first hop number, the second time length, and the third time length.

[0226] That is, the first terminal can directly determine the time length of the first timer suitable for establishing a connection with the network device on the first link according to the information of the first hop number, the second time length, and the third time length, so that the first terminal can receive the message transmitted by the network device for establishing a connection, and avoid erroneously interrupting the connection.

[0227] For example, assuming that the information of the first hop number indicates that the number of links directly connecting the terminals on the first link is N, the time length of the first timer can be: the second time length + (the third time length-the second time length) x N; or, the time length of the first timer can be: the third time length + (the third time length-the second time length) x (N-1).

[0228] The above is only an example, and the duration of the first timer can also be: the second duration + (the third duration ÷ K) × N, K being a number greater than or equal to 2; or, the duration of the first timer can also be: the second duration + the third duration + (the third duration - the second duration) × (N - 1), which is not specifically limited in the embodiments of the present application.

[0229] For example, assuming that the second duration is the duration of the second timer and the third duration is the duration of the third timer, based on the above timer T300 value t300, T301 value t301, T319 value t319, T300-RemoteUE-r17 value t300-RemoteUE-r17, T301-RemoteUE-r17 value t301-RemoteUE-r17, and T319-RemoteUE-r17 value t319-RemoteUE-r17, the following can be obtained:

[0230] The t300 value of the first timer = t300 + (t300-RemoteUE-r17 - t300) × N;

[0231] The t301 value of the first timer = t301 + (t301-RemoteUE-r17 - t301) × N;

[0232] The t319 value of the first timer = t319 + (t319-RemoteUE-r17 - t319) × N.

[0233] In a possible implementation, the first duration is indicated by the network device, and the first terminal determines the duration of the first timer according to the information of the first hop number and the first duration, including: the first terminal determines the duration of the first timer according to the information of the first hop number, the first duration, and the second duration and / or the third duration.

[0234] For example, assuming that the information of the first hop number indicates that the number of links directly connected between terminals on the first link is N, the duration of the first timer can be: the second duration + (the first duration) × N; or, the duration of the first timer can be: the third duration + (the first duration) × (N - 1); or, the duration of the first timer can be: the third duration + the second duration + (the first duration) × (N - 2).

[0235] For example, assuming that the second time length is the time length of the second timer, the third time length is the time length of the third timer, and the first time length is the configured t300-PC5, t301-PC5, or t319-PC5, based on the timer T300 value t300, the timer T301 value t301, the timer T319 value t319, the timer T300-RemoteUE-r17 value t300-RemoteUE-r17, the timer T301-RemoteUE-r17 value t301-RemoteUE-r17, and the timer T319-RemoteUE-r17 value t319-RemoteUE-r17, the following can be obtained:

[0236] The first timer t300 value = t300 + t300-PC5 x N;

[0237] The first timer t301 value = t301 + t301-PC5 x N;

[0238] The first timer t319 value = t319 + t319-PC5 x N.

[0239] Alternatively, the above formula can also be replaced by:

[0240] The first timer t300 value = t300-RemoteUE-r17 + t300-PC5 x (N-1);

[0241] The first timer t301 value = t301-RemoteUE-r17 + t301-PC5 x (N-1);

[0242] The first timer t319 value = t319-RemoteUE-r17 + t319-PC5 x (N-1).

[0243] In a possible implementation, the first terminal determines the time length of the first timer according to the information of the first hop number, including: the first terminal determines the time length of the first timer according to the second time length and the third time length, the second time length is the time length corresponding to that the terminal directly connects the network device, and the third time length is the time length corresponding to that the terminal connects the network device through the relay.

[0244] That is, the first terminal can directly determine the time length of the first timer suitable for establishing a connection between the first link and the network device according to the information of the first hop number, the second time length, and the third time length, so that the first terminal can receive the message transmitted by the network device for establishing a connection, and avoid mistakenly interrupting the connection.

[0245] For example, for the first hop number being the number of links directly connected between terminals on the first link N = 2, the time length of the first timer can be: the second time length + the first time length.

[0246] For example, assuming that the second duration is the duration of the second timer, the third duration is the duration of the third timer, and the first duration is the configured t300-PC5, t301-PC5, or t319-PC5, based on the timer values T300=t300, T301=t301, T319=t319, T300-RemoteUE-r17=t300-RemoteUE-r17, T301-RemoteUE-r17=t301-RemoteUE-r17, and T319-RemoteUE-r17=t319-RemoteUE-r17, the following can be obtained:

[0247] The t300 value of the first timer=t300+t300-RemoteUE-r17;

[0248] The t301 value of the first timer=t301+t301-RemoteUE-r17;

[0249] The t319 value of the first timer=t319+t319-RemoteUE-r17.

[0250] It can be understood that the first timer is of the timer type in the aforementioned “Table 1”, but considering that the first terminal connects to the network device through a relay, when the relay connection between the first terminal and the network device changes, or the relay connection between the second terminal providing relay service for the first terminal and the network device also triggers the stop of the first timer, which will be described in detail below.

[0251] In a possible implementation, the condition for triggering the stop of the first timer within the duration of the first timer after the first timer is started includes at least one of the following: the first terminal determines that a radio link failure, a link switching, or a relay reselection occurs.

[0252] It can be understood that the first terminal determining that a radio link failure, a link switching, or a relay reselection occurs can include the first terminal itself experiencing a radio link failure, a link switching, or a relay reselection, and the second terminal sending a radio link failure, a link switching, or a relay reselection.

[0253] That is, the first terminal stops the first timer when it determines that the first terminal and / or the second terminal has experienced a radio link failure, a link switching, or a relay reselection.

[0254] It can be understood that, for link switching, specifically, the connection state between the first terminal and the network device changes, or the link type between the first terminal and the network device changes, for example: the first terminal changes from being directly connected to the network device to being connected to the network device through a relay terminal; or the first terminal changes from being connected to the network device through a relay terminal to being directly connected to the network device.

[0255] In addition, relay reselection can refer to the first terminal changing from being connected to the network device through relay terminal #1 to being connected to the network device through relay terminal #2.

[0256] It can be understood that, for how the first terminal determines that the second terminal has wireless link failure, link switching, or relay reselection, the first terminal can determine whether the second terminal has wireless link failure, link switching, or relay reselection, etc. through the second indication information sent by the second terminal, which will be described in detail below.

[0257] Optionally, the method shown in FIG. 10 further includes:

[0258] S1003, the second terminal sends second indication information to the first terminal. Correspondingly, the first terminal receives the second indication information from the second terminal. The second indication information is used to indicate at least one of the following: the second terminal has wireless link failure, link switching, relay reselection, or cell switching.

[0259] S1004, in the case that the first timer is started and the first timer has not timed out, the first terminal stops the first timer.

[0260] That is, the first terminal can determine the connection state of the second terminal providing relay service for the first terminal through the second indication information, and further can stop the first timer in time based on the second indication information, so as to enter other connection procedures.

[0261] The stopping condition of the first timer will be further described below taking the establishment procedure of the first timer for RRC connection as an example.

[0262] The first terminal triggers the first timer to start after sending the RRC establishment request message. The stopping condition of the first timer includes one or more of the following:

[0263] The first terminal receives the RRC establishment message or the RRC rejection message;

[0264] The first terminal receives the second indication information of the relay terminal (i.e. the second terminal) connected to the first terminal, indicating that the second terminal has PC5 wireless link failure, link switching, or relay reselection;

[0265] The first terminal determines that the second terminal is no longer available, for example, the first terminal detects a PC5 radio link failure, for example, the first terminal detects that the quality of the PC5 signal is less than a first threshold value;

[0266] Alternatively, the upper layer of the first terminal triggers the occurrence of RRC connection establishment abortion.

[0267] It can be understood that the first threshold value can be protocol predefined, or pre-negotiated between the first terminal and the second terminal, or indicated by the second terminal, and the embodiments of the present application do not make specific limitations.

[0268] In addition, the timer stop condition in the RRC re-establishment procedure and the RRC recovery procedure is similar to that in the RRC establishment procedure, which will not be described here.

[0269] It should be understood that before the first terminal and the network device complete the connection establishment, the link state between the first terminal and the network device can change, which in turn causes the first hop number of the first link to change, and the length of the first timer needs to be determined according to the information of the changed first hop number, which will be described in detail below in conjunction with FIG. 11.

[0270] FIG. 11 is a schematic diagram of a scenario in which the first hop number changes according to an embodiment of the present application. As shown in (a) of FIG. 11, the first terminal discovers the second terminal and establishes a PC5 connection with the second terminal, and the second terminal connects the network device through the third terminal, that is, the first terminal connects the network device through 3 links (2 PC5 links and 1 Uu link), that is, the first terminal connects the network device through multi-hop relay.

[0271] As shown in (a) of FIG. 11, in the process of triggering the establishment of the RRC connection by the first terminal, or the re-establishment, or the recovery, the connection state of the second terminal (or the connection mode between the second terminal and the network device) changes, and the changed connection state of the second terminal can be referred to (b) of FIG. 11, that is, the connection between the second terminal and the network device is that the second terminal directly connects the network device.

[0272] It can be understood that in the scenario shown in (a) of FIG. 11 changes to the scenario shown in (b) of FIG. 11, the connection state of the second terminal can change as follows:

[0273] a. The second terminal is in an RRC connected state, and the connection state of the second terminal changes from being connected to the network device through the third terminal relay to being directly connected to the network device;

[0274] b. The second terminal is in an RRC idle state or an RRC inactive state, and the second terminal selects a cell, that is, the second terminal changes from camping on a cell through the third terminal to camping on a cell through Uu.

[0275] It can be understood that in the case that the scenario shown in (a) of FIG. 11 changes to the scenario shown in (b) of FIG. 11, the second hop number between the second terminal and the network device decreases, which in turn causes the first hop number of the first link between the first terminal and the network device to decrease.

[0276] In addition, in the case that the scenario shown in (b) of FIG. 11 changes to the scenario shown in (a) of FIG. 11, the second hop number between the second terminal and the network device increases, which in turn causes the first hop number of the first link between the first terminal and the network device to increase. Specifically, the connection state of the second terminal can change as follows:

[0277] c. The second terminal is in an RRC connected state, and the connection state of the second terminal changes from being directly connected to the network device to being connected to the network device through the third terminal;

[0278] d. The second terminal is in an RRC idle state or an RRC inactive state, and the second terminal selects a relay, i.e., the second terminal changes from camping on a cell through Uu to camping on a cell through the third terminal.

[0279] In addition, it is also possible that the number of relays between the second terminal and the network device changes, which in turn causes the first hop number of the first link between the first terminal and the network device to increase or decrease, for example, including the following cases:

[0280] e. The second terminal is in an RRC connected state, and the connection state of the second terminal changes from being connected to the network device through X relays to being connected to the network device through Y relays, X can be greater than Y or less than Y, and X and Y are both integers greater than or equal to 1;

[0281] f. The second terminal is in an RRC idle state or an RRC inactive state, and the second terminal reselects a relay, i.e., the second terminal changes from camping on cell 1 through X relays to camping on cell 2 through X relays, where cell 1 and cell 2 can be the same cell or different cells.

[0282] When the above cases occur, the first terminal can still trigger the establishment procedure, or the reestablishment procedure, or the recovery procedure of the RRC connection through the second terminal, at this time, the first terminal needs to perceive the change of the first hop number, so as to determine the appropriate length of the first timer.

[0283] The following specifically introduces the perception of the first terminal to the change of the first hop number.

[0284] Optionally, the method shown in FIG. 10 further includes:

[0285] S1005, the second terminal sends third indication information to the first terminal. Correspondingly, the first terminal receives the third indication information from the second terminal, the third indication information indicates that the connection state of the second terminal changes, and / or the third indication information indicates the third hop number information of the second terminal connecting the network device.

[0286] That is, the first terminal receives the third indication information from the second terminal, can perceive whether the first hop number information changes, and further can determine whether to adjust the length of the first timer.

[0287] For example, the third indication information indicates that the connection state of the second terminal changes, and further can determine whether the first hop number changes according to the changed connection state of the second terminal.

[0288] For another example, for the third indication information indicating the third hop number information of the second terminal connecting the network device, the first terminal can determine whether the first hop number changes according to whether the second hop number information indicated by the first indication information is same as the third hop number information.

[0289] In a possible implementation, the third indication information indicates that the connection state of the second terminal changes, including: the connection state changes from a first state to a second state; wherein the connection state changes from the first state to the second state, including:

[0290] The second terminal changes from directly connecting with the network device to connecting with the network device through the relay device; or

[0291] The second terminal changes from connecting with the network device through the relay to directly connecting with the network device; or

[0292] The second terminal changes the relay between the second terminal and the network device.

[0293] That is, by indicating the connection state of the second terminal before and after the change through the third indication information, it can be determined whether the first hop number changes. Further optionally, the first hop number information after the change can also be known.

[0294] It can be understood that the above is only an example, and the third indication information indicating that the connection state of the second terminal changes can also include: indicating which specific actions occur to the second terminal, for example, the second terminal occurs cell selection, relay selection, cell reselection, or relay reselection, etc., and the embodiments of the present application do not make specific limitations.

[0295] It can also be understood that the cell selection and the relay selection can refer to the related description in FIG. 11, which will not be repeated here.

[0296] In addition, for cell reselection, it can refer to a scenario where the second terminal directly connects the network device, and the second terminal camps on other messages through Uu. For relay reselection, it can refer to a scenario where the second terminal changes from connecting the network device through the third terminal to connecting the network device through the fourth terminal.

[0297] It can be understood that for the above cell selection, relay selection, cell reselection, or relay reselection, the third indication information can also specifically indicate the device connected after the change or the cell camped, and the embodiments of the present application do not make specific limitations.

[0298] In a possible implementation, the method shown in FIG. 10 further includes:

[0299] S1006, the first terminal determines the updated first hop count information according to the third indication information.

[0300] S1007, the first terminal determines the duration of the first timer according to the updated first hop count information.

[0301] That is, the first terminal can determine the duration of the first timer through the updated first hop count information according to the third indication information, so as to adaptively adjust the duration of the first timer according to the changed first hop count information.

[0302] In the embodiments of the present application, the first terminal can determine the first hop count information of the first link through which the first terminal connects the network device through the second terminal through the first indication information from the second terminal, and further determine the duration of the first timer suitable for establishing a connection with the network device on the first link according to the first hop count information of the first link.

[0303] The embodiments of the present application also provide a communication device for implementing the above various methods. The communication device can be the first terminal or the second terminal in the above method embodiments, or a device containing the above first terminal or the second terminal, or a component that can be used for the first terminal or the second terminal. It can be understood that the communication device contains the corresponding hardware structure and / or software module for implementing each function. Those skilled in the art should easily realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed in the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is driven by hardware or computer software to drive hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0304] The embodiments of the present application can divide the functional modules of the communication device according to the method embodiments, for example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The integrated module can be realized in the form of hardware or in the form of a software functional module. It should be noted that the division of the modules in the embodiments of the present application is illustrative, and is only a logical functional division. In actual implementation, another division mode can be used.

[0305] Taking the communication device as the first terminal or the second terminal in the method embodiments, FIG. 12 is a structural schematic diagram of a communication device provided by an embodiment of the present application. As shown in FIG. 12, the communication device 1200 includes a processing module 1201 and a transceiver module 1202. The processing module 1201 is configured to perform the processing functions of the first terminal or the second terminal in the method embodiments. The transceiver module 1202 is configured to perform the transceiving functions of the first terminal or the second terminal in the method embodiments.

[0306] The above method embodiments involve all related contents of each step, which can be referred to the function description of the corresponding functional module, and will not be repeated here.

[0307] Since the communication device 1200 provided by the embodiment can perform the above communication method, the technical effects that can be obtained thereby can be referred to the method embodiments, and will not be repeated here.

[0308] In a possible design, the transceiver module 1202 can include a receiving module and a sending module (not shown in FIG. 12). The transceiver module is configured to implement the sending function and the receiving function of the communication device 1200.

[0309] In a possible design, the communication device 1200 can further include a storage module (not shown in FIG. 12), which stores programs or instructions. When the processing module 1201 executes the programs or instructions, the communication device 1200 can perform the functions of the first terminal or the second terminal in the method shown in FIG. 10.

[0310] It should be understood that the processing module 1201 involved in the communication device 1200 can be realized by a processor or a processor-related circuit component, and can be a processor or a processing unit. The transceiver module 1202 can be realized by a transceiver or a transceiver-related circuit component, and can be a transceiver or a transceiving unit.

[0311] Exemplarily, FIG. 13 is a structural schematic diagram of another communication apparatus provided by the embodiments of the present application. The communication apparatus can be a first terminal, or a second terminal, or a chip (system) or other components or assemblies that can be arranged in the first terminal or the second terminal. As shown in FIG. 13, the communication apparatus 1300 can include a processor 1301. In a possible design, the communication apparatus 1300 can further include a memory 1302 and / or a transceiver 1303. The processor 1301 is coupled with the memory 1302 and the transceiver 1303, for example, through a communication bus.

[0312] The components of the communication apparatus 1300 will be described in detail below in combination with FIG. 13.

[0313] The processor 1301 is the control center of the communication apparatus 1300, which can be one processor or collectively refer to multiple processing elements. For example, the processor 1301 can be one or more central processing units (CPUs), application specific integrated circuits (ASICs), or one or more integrated circuits configured to implement one or more of the embodiments of the present application, such as one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs).

[0314] In a possible design, the processor 1301 can perform various functions of the communication apparatus 1300 by running or executing software programs stored in the memory 1302, and calling data stored in the memory 1302.

[0315] In a specific implementation, as an example, the processor 1301 can include one or more CPUs, for example, CPU0 and CPU1 shown in FIG. 13.

[0316] In a specific implementation, as an example, the communication apparatus 1300 can also include multiple processors, for example, the processor 1301 and the processor 1304 shown in FIG. 13. Each of the processors can be a single-CPU or a multi-CPU. The processor herein can refer to one or more devices, circuits, and / or processing cores for processing data (for example, computer program instructions).

[0317] The memory 1302 is configured to store software programs for implementing the solutions of the present application, and the processor 1301 is configured to control the execution of the software programs. For details, refer to the methods described above, which will not be repeated here.

[0318] In a possible design, the memory 1302 can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, and can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, a magneto-optical disc storage (including a compact disc, a laser disc, an optical disc, a digital versatile disc, a Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but the present application is not limited thereto. The memory 1302 can be integrated with the processor 1301 or exist independently and be coupled to the processor 1301, and the embodiments of the present application do not make a specific limitation in this regard.

[0319] The transceiver 1303 is configured to communicate with other communication devices. For example, the communication device 1300 is a first terminal, and the transceiver 1303 can be configured to communicate with a second terminal. For another example, the communication device 1300 is a second terminal, and the transceiver 1303 can be configured to communicate with a first terminal.

[0320] In a possible design, the transceiver 1303 can include a receiver and a transmitter (not shown in FIG. 13). The receiver is configured to implement the receiving function, and the transmitter is configured to implement the transmitting function.

[0321] In a possible design, the transceiver 1303 can be an input / output interface or an interface circuit, configured to input and / or output signals.

[0322] In a possible design, the transceiver 1303 can be integrated with the processor 1301 or exist independently and be coupled to the processor 1301, and the embodiments of the present application do not make a specific limitation in this regard.

[0323] It should be noted that the structure of the communication device 1300 shown in FIG. 13 does not constitute a limitation on the communication device, and actually, the communication device can include more or fewer components than those shown, or combine certain components, or have different component arrangements.

[0324] In addition, the communication device 1300 can perform the above-mentioned communication method, and the technical effects that can be achieved thereby can refer to the above-mentioned method embodiments, which will not be described here again.

[0325] In a possible implementation, the embodiments of the present application further provide a computer readable storage medium, which stores a computer program or instructions, and the computer program or instructions, when executed by a computer, implement the functions of the above-mentioned method embodiments.

[0326] In a possible implementation, the embodiments of the present application further provide a computer program product, which, when executed by a computer, implements the functions of the above-mentioned method embodiments.

[0327] In a possible implementation, the embodiments of the present application further provide a communication system, which includes the first terminal and the second terminal of the above-mentioned method embodiments.

[0328] In a possible implementation, the embodiments of the present application further provide a communication method, which includes the method of any of the above-mentioned method embodiments or any implementation thereof.

[0329] In the above-mentioned embodiments, all or part of the embodiments can be realized by software, hardware, firmware, or any combination thereof. When realized by software, all or part of the embodiments can be realized in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed by a computer, the computer program instructions generate the processes or functions according to the embodiments of the present application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another, for example, the computer instructions can be transferred from one website, computer, server, or data center to another through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer readable storage medium can be any available medium that can be accessed by a computer or data storage device including one or more servers, data centers, etc. integrated with the medium. The available medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium, or a semiconductor medium (such as a solid state drive (SSD)), etc.

[0330] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0331] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0332] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0333] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0334] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit.

[0335] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0336] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, the disclosure, and the appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0337] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of the claims and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A method of information transmission, characterized in that, The method applied to a first terminal comprises: receiving first indication information from a second terminal, the first indication information being used to determine information of a first hop number of a first link, the first hop number being associated with a number of network devices and / or terminals on the first link, the first link being a wireless link through which the first terminal connects the network devices via the second terminal; determining a time length of a first timer according to the information of the first hop number, the time length of the first timer being a time length corresponding to the first link.

2. The method of claim 1, wherein, The first hop number is a number of terminals on the first link, or the first hop number is a sum of a number of links directly connecting the terminals on the first link and a number of links through which the terminals on the first link directly connect the network devices.

3. The method according to claim 1 or 2, characterized in that, The determining of the time length of the first timer according to the information of the first hop number comprises: determining the time length of the first timer according to the information of the first hop number and a first time length, the first time length being a time length corresponding to the links directly connecting the terminals on the first link.

4. The method of claim 3, wherein, The first time length is indicated by the network devices. Or, the first time length is determined according to a second time length and a third time length, the second time length being a time length corresponding to the terminals directly connecting the network devices, and the third time length being a time length corresponding to the terminals connecting the network devices via a relay.

5. The method of claim 4, wherein, The first time length being determined according to the second time length and the third time length comprises that the first time length is a difference between the second time length and the third time length.

6. The method according to claim 4 or 5, characterized in that, The first time length being determined according to the second time length and the third time length; the determining of the time length of the first timer according to the information of the first hop number and the first time length comprises: determining the time length of the first timer according to the information of the first hop number, the second time length, and the third time length.

7. The method according to claim 1 or 2, characterized in that, The determining of the time length of the first timer according to the information of the first hop number comprises: determining the time length of the first timer according to a second time length and a third time length, the second time length being a time length corresponding to the terminals directly connecting the network devices, and the third time length being a time length corresponding to the terminals connecting the network devices via a relay.

8. The method according to any one of claims 1-7, characterized in that, The first indication information indicates information of a second hop number of the second terminal connecting the network devices, the second hop number being associated with a number of terminals on a wireless link through which the second terminal connects the network devices. Or, the first indication information is an identifier used to indicate a relay service provided by the second terminal.

9. The method according to any one of claims 1-8, characterized in that, The condition for triggering the stopping of the first timer within the time length of the first timer when the first timer is started comprises at least one of the following: determining that a radio link failure, a link switching, or a relay reselection occurs.

10. The method according to any one of claims 1-9, characterized in that, The method further comprises: receiving second indication information from the second terminal, the second indication information being used to indicate at least one of the following: the second terminal occurs a radio link failure, a link switching, a relay reselection, or a cell switching.

11. The method according to any one of claims 1-10, characterized in that, The method further comprises: receive third indication information from the second terminal, the third indication information indicating that a connection state of the second terminal changes, and / or information of a third hop number of the second terminal connecting the network device.

12. The method of claim 11, wherein, The third indication information indicating that the connection state of the second terminal changes includes: the connection state changing from a first state to a second state; wherein the connection state changing from the first state to the second state includes: The second terminal changes from directly connecting the network device to connecting the network device through a relay terminal; or The second terminal changes from connecting the network device through a relay to directly connecting the network device.

13. The method according to claim 11 or 12, characterized in that, The method further includes: determining updated first hop number information according to the third indication information; determining a time length of a first timer according to the updated first hop number information.

14. The method of any one of claims 1-13, wherein, The first timer is used for a radio resource control (RRC) connection establishment procedure, or a re-establishment procedure, or a recovery procedure.

15. An information transmission method, characterized by, The method applied to a second terminal includes: determining first indication information, the first indication information indicating second hop number information of the second terminal connecting the network device, the second hop number being associated with a number of terminals on a wireless link of the second terminal connecting the network device; or the first indication information being an identifier of a relay service provided by the second terminal; sending the first indication information to the first terminal.

16. The method of claim 17, wherein, The method further includes: sending second indication information to the first terminal, the second indication information being used to indicate at least one of the following: the second terminal experiencing a radio link failure, a link switching, a relay reselection, or a cell switching.

17. The method according to claim 15 or 16, characterized in that, The method further includes: sending third indication information to the first terminal, the third indication information indicating that a connection state of the second terminal changes, and / or information of a third hop number of the second terminal connecting the network device.

18. The method of claim 17, wherein, The third indication information indicating that the connection state of the second terminal changes includes: the connection state changing from a first state to a second state; wherein the connection state changing from the first state to the second state includes: The second terminal changes from directly connecting the network device to connecting the network device through a relay device; or The second terminal changes from connecting the network device through a relay to directly connecting the network device.

19. A communications device, characterized by The communication apparatus includes a module or unit for performing the method of any of claims 1-18.

20. A communications device, characterized by The communication apparatus includes a processor configured to cause the communication apparatus to perform the method of any of claims 1-18 by means of a logic circuit and / or executing instructions.

21. The communication apparatus according to claim 20, wherein, The communication apparatus is a chip.

22. A computer-readable storage medium, characterized in that, The computer readable storage medium includes instructions that, when executed by a processor, cause the method of any of claims 1-18 to be implemented.

23. A computer program product, characterised in that, The computer program product includes instructions that, when executed on a computer, cause the computer to perform the method of any of claims 1-18.

24. A communication system, characterized by The communication system comprises a first terminal for performing the method according to any one of claims 1-14 and a second terminal for performing the method according to any one of claims 15-18.

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