Communication method, communication device, and communication system

Abstract

The application discloses a communication method, a communication device and a communication system, which can avoid data interruption of a remote terminal. The method comprises the following steps: receiving radio resource control release information sent by a first network device, wherein the radio resource control release information is used for indicating that a first radio resource control connection between a first terminal and the first network device is released; and sending first indication information to a second terminal, wherein the first terminal is a relay device of the second terminal for accessing the first network device, and the first indication information is used for indicating that a sidelink between the first terminal and the second terminal is released, or used for indicating that the first radio resource control connection is released, or used for indicating that a state of the first radio resource control connection is a connection failure state.

Description

[0001] This application claims priority to Chinese patent application No. 202210023783.X, filed on January 10, 2022, entitled "Communication Method, Communication Apparatus and Communication System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and more specifically, to a communication method, communication device and communication system. Background Technology

[0003] A relay terminal can act as a relay device to relay data transmitted between a remote terminal and a network device. In some cases, the network device may release the radio resource control (RRC) connection between the relay terminal and the network device. This may result in data transmission interruption at the remote terminal. Summary of the Invention

[0004] This application provides a communication method, communication device, and communication system that can prevent data transmission interruption at remote terminals.

[0005] In a first aspect, a communication method is provided, comprising: receiving radio resource control release information sent by a first network device, the radio resource control release information being used to indicate the release of a first radio resource control connection between a first terminal and the first network device; sending first indication information to a second terminal, the first terminal being a relay device for the second terminal to access the first network device, the first indication information being used to indicate at least one of the following: releasing a sidelink between the first terminal and the second terminal, indicating that the first radio resource control connection has been released, and indicating that the state of the first radio resource control connection is a connection failure state.

[0006] When the first radio resource control connection between the first terminal (acting as a relay device) and the first network device is released, the first terminal sends a first instruction message to the second terminal (acting as a remote device). Thus, the remote terminal can perform subsequent processing based on the first instruction message, avoiding data interruption during remote terminal transmission.

[0007] In some possible implementations, the method further includes: establishing a second radio resource control connection with a second network device, the second radio resource control connection being used by the second terminal to access the second network device.

[0008] When the first radio resource control connection between the first terminal, which acts as a relay device, and the first network device is released, the first terminal establishes a second radio resource control connection with the second network device, thereby enabling the second terminal to access the second network device through the second radio resource control connection and avoiding interruption of data transmission by the second terminal.

[0009] In some possible implementations, the method further includes: receiving second indication information sent by the second terminal, the second indication information being used to indicate maintaining the side link.

[0010] Upon receiving a second instruction message from the second terminal instructing the maintenance of the sidelink, the first terminal establishes a second radio resource control (RRR) connection with the second network device. In other words, the establishment of the second RRR connection depends on the second terminal's response to the first instruction message instructing the maintenance of the sidelink, thus avoiding the establishment of an invalid RRR connection and reducing resource consumption.

[0011] In some possible implementations, establishing a second radio resource control (RRC) connection with the second network device includes: establishing an RRC connection with the second network device if the sidelink is not disconnected at the detection time point, wherein the detection time point includes a time point after the first indication information is sent for a first duration.

[0012] The fact that the sidelink was not disconnected at the detection time point can be understood as the second terminal's response to the first indication information to maintain the sidelink. In other words, the establishment of the second radio resource control connection depends on the second terminal's response to the first indication information to maintain the sidelink, thus avoiding the establishment of the second radio resource control connection in the event of invalidity and reducing resource consumption.

[0013] In some possible implementations, the method further includes: the radio resource control release information is received when the first terminal meets the handover conditions and there is no session belonging to the first terminal between the first terminal and the first network device.

[0014] The handover condition may be, for example, the fulfillment of at least one measurement event. After the first terminal establishes an RRC connection with the first network device, the first network device may send at least one measurement event to the first terminal. The first terminal device may perform measurements periodically or non-periodically. If any one or more of the at least one measurement event is met, the first terminal may send a measurement report to the first network device. Upon receiving the measurement report, the first network device can determine that the handover condition has been met.

[0015] The first network device may send at least one measurement event to the first terminal, which may include one or more of the following events: the serving cell signal quality becomes lower than a corresponding threshold; the neighboring cell signal quality begins to be higher than the serving cell signal quality by a certain offset; the neighboring cell signal quality becomes higher than a corresponding threshold; the serving cell signal quality becomes lower than threshold 1 and the neighboring cell signal quality becomes higher than threshold 2; the neighboring cell signal quality begins to be higher than the secondary cell (Scell) signal quality by a certain offset; the inter-system (inter-radio access technology, Inter-RAT) neighboring cell signal quality becomes higher than a corresponding threshold; the primary cell (Pcell) signal quality becomes lower than threshold 1 and the inter-system neighboring cell signal quality becomes higher than threshold 2.

[0016] If the first terminal meets the handover conditions and there is no session belonging to the first terminal between the first terminal and the first network device, the first network device may send a radio resource control release message to the first terminal and release the first radio resource control connection with the first terminal.

[0017] In some possible implementations, the method further includes: determining the connection status of the first radio resource control connection; sending status indication information to the second terminal, the status indication information including first status information, second status information or third status information, wherein the first status information is used to indicate that the connection status is in the process of being established, the second status information is used to indicate that the connection status is in the process of being established, the third status information is used to indicate that the connection status is in the process of being established, and the third status information is used to indicate that the connection status is in the process of being established.

[0018] The first terminal sends status indication information to the second terminal to indicate the connection status of the first radio resource control connection, thereby eliminating the need to indicate events related to the first radio resource control connection and reducing information redundancy.

[0019] It should be understood that after the first terminal establishes a second radio resource control (RRC) connection with the second network device, the first terminal can send status indication information to the second terminal to indicate the connection status of the second RRC connection. In other words, the status indication information is used to indicate the RRC connection between the first terminal and the network device serving the first terminal.

[0020] In some possible implementations, determining the connection state of the first radio resource control (RRR) connection includes: determining the connection state as the "establishing" state when the first terminal is switching, the first RRR connection is being established, or the first RRR connection that has experienced a radio link failure is being restored; determining the connection state as the "established" state when the first terminal completes the switch, the first RRR connection is established, or the recovery from the radio link failure of the first RRR connection is completed; and determining the connection state as the "established" state when the first terminal device fails to switch, the first RRR connection fails to establish, the first RRR connection experiences a radio link failure, the recovery from the radio link failure of the first RRR connection fails, or the first RRR connection is released.

[0021] For multiple events related to the first radio resource control connection, if the state of the radio resource control connection between the first terminal and the network device is the same, the same information can be used for indication, thereby reducing the number of bits required for the information and reducing the redundancy of the information.

[0022] In a second aspect, a communication method is provided, the method comprising: determining the connection status of a first radio resource control connection between a first terminal and a first network device; sending status indication information to a second terminal, the status indication information including first status information, second status information or third status information, wherein the first status information is used to indicate that the connection status is in the process of being established, the second status information is used to indicate that the connection status is in the process of being established, the third status information is used to indicate that the connection status is in the process of being established, and the first terminal is a relay device for the second terminal to access the first network device.

[0023] The first terminal sends status indication information to the second terminal to indicate the connection status of the first radio resource control connection, thereby eliminating the need to indicate events related to the first radio resource control connection and reducing information redundancy.

[0024] In some possible implementations, determining the connection status of the first radio resource control (RRC) connection between the first terminal and the first network device includes: determining the connection status as the "establishing" state when the first terminal is switching over, the first RRC connection is being established, or the first RRC connection that has experienced a radio link failure is being restored; determining the connection status as the "established" state when the first terminal completes the switchover, the first RRC connection is established, or the recovery from the radio link failure of the first RRC connection is completed; and determining the connection status as the "established" state when the first terminal device fails to switch over, the first RRC connection fails to establish, the first RRC connection experiences a radio link failure, the recovery from the radio link failure of the first RRC connection fails, or the first RRC connection is released.

[0025] In some possible implementations, determining the connection status of the first radio resource control connection between the first terminal and the first network device includes: upon receiving radio resource control release information sent by the first network device, determining the connection status as the establishment failure status, wherein the radio resource control release information is used to indicate the release of the first radio resource control connection.

[0026] In some possible implementations, the method further includes: establishing a second radio resource control connection with a second network device, the second radio resource control connection being used by the second terminal to access the second network device.

[0027] In some possible implementations, the method further includes: receiving second indication information sent by the second terminal, the second indication information being used to indicate maintaining the side link.

[0028] In some possible implementations, establishing a second radio resource control (RRC) connection with the second network device includes: establishing an RRC connection with the second network device if the sidelink is not disconnected at the detection time point, wherein the detection time point includes a time point after the first indication information is sent for a first duration.

[0029] In some possible implementations, the radio resource control release information is received when the first terminal meets the handover conditions and there is no session belonging to the first terminal between the first terminal and the first network device.

[0030] Thirdly, a communication method is provided. The method includes: determining that a first terminal meets handover conditions, and that there is no session belonging to the first terminal between the first terminal and a first network device, the first terminal is a relay device for a second terminal to access the first network device, and a first radio resource control (RFC) connection exists between the first terminal and the first network device; and sending RRC release information to the first terminal, the RRC release information being used to instruct the release of the first RRC connection between the first terminal and the first network device.

[0031] When the first network device determines that the first terminal meets the handover conditions and there is no session belonging to the first terminal, it instructs the first terminal to release the radio resource control connection, thereby enabling the first terminal to send a first instruction message to the second terminal, and the second terminal to perform subsequent processing according to the first instruction message, thus avoiding interruption of data transmission by the second terminal.

[0032] In some possible implementations, the method further includes: receiving a measurement report from a first terminal, the measurement report including information indicating the signal quality measured by the first terminal; and determining, based on the measurement report, that the first terminal meets the handover conditions.

[0033] The first network device can determine whether the first terminal meets the handover conditions based on the measurement report from the first terminal, and thus determine whether it is necessary to send handover instruction information to the first terminal.

[0034] In some possible implementations, the method further includes: releasing the first radio resource control connection between the first terminal and the first network device.

[0035] The first network device can release the first radio resource control connection with the first terminal after sending radio resource control release information to the first terminal.

[0036] Fourthly, a communication method is provided. The method includes: determining whether a session belonging to the first terminal exists between a first terminal and a first network device, the first terminal being a relay device for a second terminal to access the first network device; when no session belonging to the first terminal exists, sending a first radio resource control reconfiguration message to the first terminal, the first radio resource control reconfiguration message including information indicating at least one unmeasurable cell and / or at least one measurable cell covered by the first network device.

[0037] When there is no session belonging to the first terminal, the first network device can instruct the first terminal to only measure the cells covered by the first network device, thereby enabling the first terminal to switch from the current serving cell to a cell with better signal quality covered by the first network device, thus avoiding data interruption for the second terminal through the first terminal.

[0038] In some possible implementations, the method further includes: when a session belonging to the first terminal exists, sending a second radio resource control reconfiguration message to the first terminal, the second radio resource control reconfiguration message including information for indicating cells and / or other cells covered by the first network device, wherein the other cells are cells outside the cells covered by the first network device.

[0039] When a session belonging to the first terminal exists, the first network device can send a second radio resource control reconfiguration message to the first terminal, so that the first terminal can perform signal measurement based on the second radio resource control reconfiguration message to determine whether there is a cell with better signal quality.

[0040] In some possible implementations, the second radio resource control reconfiguration message includes any one or more of the following: at least one measurement event, a whitelist of measurable cells or a blacklist of unmeasurable cells, wherein the whitelist of measurable cells includes at least one measurable cell within or outside the coverage area of ​​the first network device, and the blacklist of unmeasurable cells includes at least one unmeasurable cell.

[0041] The first network device can send a second radio resource control reconfiguration message to the first terminal, thereby enabling the first terminal to switch to a network with better signal quality when a session belonging to the first terminal exists.

[0042] In some possible implementations, the method further includes: receiving a first measurement report from a first terminal, the first measurement report being determined based on a first radio resource control reconfiguration message or a second radio resource control reconfiguration message.

[0043] The first network device can send different radio resource control reconfiguration messages to the first terminal, and can also receive the first measurement report from the first terminal, thereby determining whether it is necessary to send handover instruction information to the first terminal.

[0044] In some possible implementations, the method further includes: receiving a second measurement report from a first terminal, the second measurement report including information indicating the signal quality measured by the first terminal; and determining, based on the second measurement report, that the first terminal meets the handover conditions.

[0045] The first network device can determine whether the first terminal meets the handover conditions based on the second measurement report from the first terminal, and thus determine whether it needs to send handover instruction information to the first terminal. The first network device can also determine whether a session belonging to the first terminal exists after receiving the second measurement report, and thus send a first radio resource control reconfiguration message or a second radio resource control reconfiguration message to the first terminal.

[0046] Fifthly, a communication method is provided. The method includes: when there is no session belonging to the first terminal between a first terminal and a first network device, receiving a first radio resource control reconfiguration message from the first network device, the first radio resource control reconfiguration message including information indicating at least one unmeasurable cell and / or at least one measurable cell covered by the first network device, the first terminal being a relay device for a second terminal to access the first network device; and performing signal measurement based on the first radio resource control reconfiguration message.

[0047] When there is no session belonging to the first terminal, the first terminal can perform signal measurement according to the first radio resource control reconfiguration message, thereby avoiding the interruption of the connection with the first network device, which would prevent the second terminal from transmitting data to the first network device through the first terminal.

[0048] In some possible implementations, when a session belonging to the first terminal exists, a second radio resource control reconfiguration message is received from the first network device. The second radio resource control reconfiguration message includes information indicating cells covered by the first network device and / or other cells, where other cells are cells outside the cells covered by the first network device. Signal measurement is performed based on the second radio resource control reconfiguration message.

[0049] When a session belonging to the first terminal exists, the first terminal can perform signal measurement based on the first radio resource control reconfiguration message, thereby determining whether there is a cell with better signal quality.

[0050] In some possible implementations, the second radio resource control reconfiguration message includes any one or more of the following: at least one measurement event, a whitelist of measurable cells or a blacklist of unmeasurable cells, wherein the whitelist of measurable cells includes at least one measurable cell within or outside the coverage area of ​​the first network device, and the blacklist of unmeasurable cells includes at least one unmeasurable cell.

[0051] The first terminal can perform signal measurement based on the first radio resource control reconfiguration message, and then switch to a network with better signal quality when a session belonging to the first terminal exists.

[0052] In some possible implementations, the method further includes: sending a first measurement report to a first network device, the first measurement report being determined based on a first radio resource control reconfiguration message or a second radio resource control reconfiguration message.

[0053] The first terminal can perform signal measurements based on different radio resource control reconfiguration messages and send different measurement reports to the first network device, thereby enabling the first network device to obtain information on the signal quality of each cell.

[0054] In some possible implementations, the method further includes: sending a second measurement report to the first network device before receiving a first radio resource control reconfiguration message or a second radio resource control reconfiguration message from the first network device, the second measurement report including information for indicating the signal quality measured by the first terminal.

[0055] The first terminal can send a second measurement report to the first network device, thereby reporting the measured signal quality to the first network device and enabling the first network device to determine whether to send a first radio resource control reconfiguration message or a second radio resource control reconfiguration message. Alternatively, the first terminal can send the second measurement report to the first network device, thereby enabling the first network device to determine not to send a radio resource control reconfiguration message and not to perform a handover to the first terminal.

[0056] A sixth aspect provides a communication apparatus comprising modules for performing methods in any implementation of the first, second, or fifth aspect.

[0057] A seventh aspect provides a communication apparatus comprising modules for performing the methods in any of the third or fourth aspects.

[0058] Eighthly, a communication device is provided, comprising at least one processor and a communication interface, the communication interface being used for the communication device to interact with other communication devices, wherein when program instructions are executed in the at least one processor, the communication device causes the communication device to perform a method in any implementation of any one of the first, second, or fifth aspects.

[0059] A ninth aspect provides a communication device, including at least one processor and a communication interface, the communication interface being used for the communication device to interact with other communication devices, wherein when program instructions are executed in the at least one processor, the communication device causes the communication device to perform the method in any one of the implementations of the third or fourth aspect.

[0060] In a tenth aspect, a communication system is provided, comprising a second terminal, a communication device as described in the sixth or eighth aspect, and a communication device as described in the seventh or ninth aspect.

[0061] Eleventhly, a computer-readable medium is provided that stores program code for execution by a device, the program code including methods for performing any implementation of any one of the first, second, third, fourth, or fifth aspects.

[0062] In a twelfth aspect, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the method in any one of the implementations of the first, second, third, fourth, or fifth aspects described above.

[0063] In a thirteenth aspect, a chip is provided, the chip including a processor and a data interface, wherein the processor reads instructions stored in a memory through the data interface and executes the method in any one of the implementations of the first, second, third, fourth, or fifth aspects described above.

[0064] Optionally, as one implementation, the chip may further include a memory storing instructions, and the processor is used to execute the instructions stored in the memory. When the instructions are executed, the processor is used to execute the method in any one of the first, second, third, fourth, or fifth aspects.

[0065] The aforementioned chip can be a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). Attached Figure Description

[0066] Figure 1 This is a schematic diagram of a scenario for communication between devices.

[0067] Figure 2 This is a schematic flowchart of a communication method.

[0068] Figure 3 This is a schematic flowchart of a communication method provided in an embodiment of this application.

[0069] Figure 4 This is a schematic flowchart illustrating another communication method provided in an embodiment of this application.

[0070] Figure 5 This is a schematic flowchart illustrating another communication method provided in the embodiments of this application.

[0071] Figure 6 This is a schematic flowchart of a communication method provided in an embodiment of this application.

[0072] Figure 7 This is a schematic flowchart illustrating another communication method provided in an embodiment of this application.

[0073] Figure 8This is a schematic structural diagram of a communication device provided in an embodiment of this application.

[0074] Figure 9 This is a schematic structural diagram of another communication device provided in the embodiments of this application.

[0075] Figure 10 This is a schematic structural diagram of a communication device provided in an embodiment of this application.

[0076] Figure 11 This is a schematic structural diagram of another communication device provided in the embodiments of this application.

[0077] Figure 12 This is a schematic structural diagram of another communication device provided in the embodiments of this application. Detailed Implementation

[0078] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0079] The technical solutions of this application embodiment can be applied to various communication systems, such as: Global System for Mobile Communications (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, 5th Generation (5G) system, or New Radio (NR), etc.

[0080] Figure 1 This is a schematic diagram illustrating a scenario of inter-device communication. Figure 1In scenario 100 shown, there are two main communication interfaces: the communication interface between terminal 121 and network device 110 (Uu port) and the communication interface between terminal 121 and terminal 122 (PC5 port). The Uu port is used for communication between user equipment and base stations or roadside units, while the PC5 port is used for sidelink communication between terminals. The link on the Uu port where a terminal sends data to the base station is called the uplink, and the link where a terminal receives data from the base station is called the downlink. The communication interface between terminals is called the PC5 port. The link on the PC5 port where terminals transmit data is called a sidelink or direct link. Sidelinks are generally used in device-to-device (D2D) scenarios where direct communication between devices is possible, and in these scenarios, data transmission between devices does not need to pass through a base station. Vehicle-to-everything (V2X) communication can be considered a special case of D2D communication.

[0081] On the Uu interface, data and radio resource control (RRC) signaling are transmitted between the terminal and the base station via radio bearers. The radio bearer used for data transmission is called the data radio bearer (DRB), and the bearer used for RRC signaling is called the signaling radio bearer (SRB). A radio bearer includes a packet data convergence protocol (PDCP) entity and a radio link control (RLC) bearer. An RLC bearer includes an RLC entity and a corresponding logical channel (LCH). The configuration of a radio bearer is the configuration of its PDCP entity, RLC entity, and logical channel. The configuration of a radio bearer must guarantee the quality of service (QoS) requirements of the services transmitted through it. On the Uu interface, the configuration of the radio bearer is configured by the network equipment for the terminal.

[0082] On the PC5 port, terminals also need to transmit data and RRC signaling via radio bearers. The radio bearer on the PC5 port can be called a sidelink radio bearer (SLRB). In a Long Term Evolution (LTE) V2X system, the radio bearer on the PC5 port is established by both the transmitting and receiving terminals themselves. The configuration of the radio bearer is either predefined by the standard or determined by the transmitting and receiving terminals themselves.

[0083] The terminal can communicate with network devices. The terminal can refer to an access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, user equipment (UE), wireless communication device, user agent, or user device. User equipment can also be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, vehicle-mounted device, wearable device, terminal in a 5G network, or any form of user equipment in a future network, etc. This application embodiment does not limit this.

[0084] The network device in this application embodiment can be a device for communicating with a terminal, used to connect the terminal to a radio access network (RAN). A network device may also be referred to as an access network device, access network node, or base station. It is understood that the name of a device with base station functionality may differ in systems employing different wireless access technologies. For ease of description, this application embodiment refers to any device providing wireless communication access functionality to a terminal as a network device. The network device can be a base station (BTS) in a Global System for Mobile Communications (GSM) system or Code Division Multiple Access (CDMA) system, a base station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA) system, an evolved NodeB (eNB or eNodeB) in an LTE system, a radio controller in a cloud radio access network (CRAN) scenario, or a relay station, access point, vehicle-mounted equipment, wearable device, or network equipment in a 5G network or a future evolved PLMN network. It can also be one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a next-generation Node Base station (gNB) or transmission point, such as a baseband unit (BBU) or a distributed unit (DU), etc. The embodiments of this application are not limited.

[0085] In this embodiment, the terminal or network device includes a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system can be any one or more computer operating systems that implement business processing through processes, such as Linux, Unix, Android, iOS, or Windows. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. Furthermore, this embodiment does not specifically limit the specific structure of the execution entity of the method provided in this embodiment, as long as it can communicate according to the method provided in this embodiment by running a program that records the code of the method provided in this embodiment. For example, the execution entity of the method provided in this embodiment can be a terminal or network device, or a functional module in the terminal or network device that can call and execute a program, such as a chip or processor.

[0086] Furthermore, various aspects or features of this application can be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROMs), cards, sticks, or key drives, etc.). Additionally, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0087] To improve network performance, D2D communication supports User Equipment to Network Relay (UE-to-network relay, U2N Relay). A relay terminal can act as a relay device to relay data transmitted between remote terminals and network devices. In scenario 100, terminal 121 can act as a relay terminal, and terminal 121 can also act as a remote terminal.

[0088] Figure 2This is a schematic flowchart of a communication method. Method 200 includes steps S201 to S208.

[0089] In S201, the source base station sends a first RRC reconfiguration message to the terminal. The first RRC reconfiguration message configures at least one measurement event for the terminal to measure the signals of each base station.

[0090] The first RRC reconfiguration message can be used to configure at least one measurement event. For example, one of the at least one measurement event could be that the signal strength of the serving cell is below a threshold and the signal strength of the target cell is above a threshold.

[0091] An RRC connection is established between the terminal and the source base station. The serving cell is one of at least one cell covered by the source base station. The target cell can be one of at least one cell covered by the target base station.

[0092] The terminal can perform measurements based on the at least one measurement event. For example, one of the at least one measurement events could be that the signal strength of the source base station is less than a threshold and the signal strength of the target base station is greater than or equal to the threshold, in which case the terminal can measure the signal strength of each base station.

[0093] For example, after establishing an RRC connection with the terminal, the source base station may send a first RRC reconfiguration message to the terminal. The terminal may periodically perform measurements and determine whether the measurement results meet any of the at least one measurement event.

[0094] In S202, if the measurement result satisfies any one of the measurement events, the terminal sends a measurement report (MR) to the source base station.

[0095] The MR may include measurement events in which the measurement results match at least one measurement event. The MR may also include a target cell or target base station that causes the measurement results to match the measurement time. The target cell may be a cell covered by the target base station.

[0096] In S203, the source base station sends a handover request message to the target base station based on the MR sent by the terminal.

[0097] After receiving the MR sent by the terminal, the source base station can send a handover request message to the target base station if the terminal has services available.

[0098] In S204, the target base station can send a handover confirmation message to the source base station.

[0099] The target base station decides whether to allow the terminal to access the network based on factors such as the number of other terminals connected to it. If the target base station decides to allow the terminal to access the network, it can send a handover confirmation message to the source base station.

[0100] The handover confirmation message may include information about the target cell and the configuration parameters required for the terminal to access the target cell. The target cell information may include one or more of the following: the target cell's physical cell identifier (PCI), the frequency information corresponding to the target cell, and the cell radio network temporary identifier (C-RNTI) assigned to the terminal by the target base station. The configuration parameters required for the terminal to access the target cell may include one or more of the following: random access channel (RACH) resource information (e.g., dedicated RACH resources and / or public RACH resources), and the target base station's security-related algorithms.

[0101] In S205, the source base station can send a handover command message to the terminal.

[0102] The handover command message (which can also be understood as the second RRC reconfiguration message) may include relevant information about the target cell and the relevant configuration parameters required for the terminal to access the target cell.

[0103] In S206, the terminal initiates random access to the target base station according to the handover command and establishes an RRC connection with the target base station.

[0104] After disconnecting the RRC connection with the source base station, the terminal can initiate random access to the target base station and establish an RRC connection with the target base station after accessing it.

[0105] In S207, the terminal sends an RRC reconfiguration complete message to the target base station.

[0106] When the terminal successfully establishes an RRC connection with the target base station, it can send an RRC reconfiguration complete message to the target base station.

[0107] In S208, the target base station sends an RRC connection release message to the source base station.

[0108] After receiving the context release message, the source base station can release the context of the terminal.

[0109] Using method 200, the terminal can complete handover (HO) between cells.

[0110] If the base station releases the RRC connection with the relay terminal, it may cause data interruption for the remote terminal. For example, when Figure 2If the terminal in the signal is a relay terminal and there is no protocol data unit (PDU) session between the terminal and the source base station, the source base station will not perform S203 after receiving the MR, which may lead to data interruption of the remote terminal.

[0111] In order to solve Figure 2 To address the issue of remote terminal data interruption in certain scenarios or other situations, this application provides a communication method.

[0112] Figure 3 This is a schematic flowchart illustrating a communication method provided in an embodiment of this application. Method 300 includes steps S310 to S330. The device executing steps S320 and S330 can be a first terminal or a component in the first terminal, such as a chip.

[0113] In S310, the first network device determines that the first terminal meets the handover conditions and that there is no session belonging to the first terminal.

[0114] The first network device can determine whether the first terminal meets the handover conditions, and can also determine whether there is a session belonging to the first terminal between the first network device and the first terminal. The first terminal is a relay device for the second terminal to access the first network device, and there is a first radio resource control connection (i.e., a first RRC connection) between the first terminal and the first network device.

[0115] The handover condition may be, for example, the fulfillment of at least one measurement event. After the first terminal establishes an RRC connection with the first network device, the first network device may send at least one measurement event to the first terminal. The first terminal device may perform measurements periodically or non-periodically. If any one or more of the at least one measurement event is met, the first terminal may send a measurement report to the first network device. Upon receiving the measurement report, the first network device can determine that the handover condition has been met.

[0116] For example, a measurement report can be used to indicate at least one measurement event that has been met.

[0117] The first network device may send at least one measurement event to the first terminal, which may include one or more of the following events: the serving cell signal quality becomes lower than a corresponding threshold; the neighboring cell signal quality begins to be higher than the serving cell signal quality by a certain offset; the neighboring cell signal quality becomes higher than a corresponding threshold; the serving cell signal quality becomes lower than threshold 1 and the neighboring cell signal quality becomes higher than threshold 2; the neighboring cell signal quality begins to be higher than the secondary cell (Scell) signal quality by a certain offset; the inter-system (inter-radio access technology, Inter-RAT) neighboring cell signal quality becomes higher than a corresponding threshold; the primary cell (Pcell) signal quality becomes lower than threshold 1 and the inter-system neighboring cell signal quality becomes higher than threshold 2.

[0118] When the first network device determines that the first terminal meets the handover conditions, the first network device may further determine whether there is a session belonging to the first terminal. If there is no session belonging to the first terminal, the first network device may send a connection release message to the first terminal, which is used to indicate the release of the first RRC connection between the first terminal and the first network device.

[0119] Before the first network device determines whether the first terminal meets the handover conditions, the first network device may receive a measurement report from the first terminal, which includes information indicating the signal quality measured by the first terminal. The first network device can determine whether the first terminal meets the handover conditions based on the measurement report.

[0120] After the first network device sends a radio resource control release message to the first terminal, the first network device can also release the first radio resource control connection with the first terminal.

[0121] In S320, a connection release indication message sent by the first network device is received.

[0122] The connection release instruction information is used to indicate the release of the connection between the first terminal and the first network device.

[0123] The connection release indication information may be, for example, a radio resource control release message, which is used to indicate the release of the first radio resource control connection between the first terminal and the first network device.

[0124] The connection release indication information can be carried in an RRC message sent by the first network device to the first terminal. That is, the first network device can send the connection release indication information to the first terminal through the first radio resource control connection before releasing the first radio resource control connection between the first terminal and the first network device.

[0125] The first network device may release the first radio resource control connection and send a radio resource control release message to the first terminal under at least one of the following conditions: receiving RRC connection release information from the network side, the load of the first network device exceeding a preset value, higher layer authentication failure, lower layer error (such as media access control (MAC) layer link failure, radio link control (RLC) layer link failure, etc.), radio link control recovery and there is no session belonging to the first terminal, the timer corresponding to the first radio resource control connection timeout, message interaction through the first radio resource control connection fails, and the handover conditions are met and there is no session belonging to the first terminal, etc.

[0126] In S330, a first indication message is sent to the second terminal, where the first terminal is a relay device for the second terminal to access the first network device. The first indication message is used to indicate at least one of the following: releasing the side link between the first terminal and the second terminal, indicating that the first radio resource control connection is released, and indicating that the state of the first radio resource control connection is a connection unacquittable state.

[0127] The first indication information can be carried in an RRC message sent from the first terminal to the second terminal via a side link. The side link between the first terminal and the second terminal can be an RRC connection established between the first terminal and the second terminal. The RRC message sent from the first terminal to the second terminal via the side link can also be called a PC5-RRC message.

[0128] The first indication information can be carried as a field in a PC5-RRC message. Alternatively, the first indication information can be a separate PC5-RRC message.

[0129] In method 300, when the wireless resource control connection between the first terminal, which acts as a relay device, and the network device is released, a first instruction message is sent to the second terminal, which acts as a remote terminal. As a result, the second terminal can perform subsequent operations according to the first instruction message, thereby avoiding data interruption.

[0130] The first indication information can be used to indicate the release of the side link between the first terminal and the second terminal. In this case, after receiving the first indication information, the second terminal can perform relay reselection, or it can initiate random access to the network device and establish an RRC connection with the network device.

[0131] The first indication information can also be used to indicate that the first radio resource control connection has been released, or to indicate that the status of the first radio resource control connection is that the connection cannot be acquired.

[0132] Compared to a specific event such as a first indication message indicating the release of a first radio resource control connection, a first indication message indicating the state of a radio resource control connection can reduce the redundancy of the first indication message.

[0133] Specifically, in cases where the radio resource control (RRC) connection between the first terminal and the network device experiences radio link failure (RLF), failure to receive RRF release information, failure to recover from RLF, failure to establish an RRC connection, or failure to handover, the second terminal, which provides relay services to the second terminal and the network device, can send third status information to the second terminal to indicate the status of the RRC connection between the first terminal and the network device. Thus, after receiving the third status information, the second terminal can perform relay reselection or initiate random access to the network device and establish an RRC connection with it. By sending the third status information from the first terminal to the second terminal, the same information can be used to indicate different specific events related to a certain connection status of the RRC connection between the first terminal and the network device, reducing the redundancy of the first indication information.

[0134] In some embodiments, the first terminal may release the side link between the first terminal and the second terminal after the first indication information is sent.

[0135] In other embodiments, the first terminal may perform subsequent operations based on the response of the second terminal to the first instruction information.

[0136] If the second terminal responds to indicate that the sidelink is maintained, the first terminal can establish a second radio resource control (RRC) connection with the second network device. This second RRC connection is used for the second terminal to access the second network device. In other words, the first terminal reselects a network device for the second terminal to provide services.

[0137] After receiving the first instruction information, the second terminal can send a second instruction information to the first terminal. The second instruction information is used to instruct the side link to be maintained. The second instruction information can be understood as the second terminal's response to the first instruction information. When the first terminal receives the second instruction information, it obtains the second terminal's response indicating that the side link should be maintained.

[0138] After receiving the first indication information, the second terminal can disconnect or maintain the side link with the first terminal. The first terminal can detect the side link after a first detection time point following the transmission of the first indication information. If the detection result at the detection time point indicates that the side link still exists, that is, the side link has not been released by the second terminal but is maintained by the second terminal, then the first terminal obtains the response from the second terminal indicating that the side link is maintained.

[0139] It should be understood that the first duration can be preset, determined by the protocol between the second terminal and the first terminal, or determined by the first terminal based on information such as the communication quality of the sidelink. This application does not limit this.

[0140] After the first terminal receives a response from the second terminal indicating that it will maintain the sidelink, the first terminal can establish a second radio resource control (RRC) connection with the second network device. Conversely, if the first terminal does not receive a second indication message from the second terminal, or if the sidelink has been released by the second terminal at the detection time, the first terminal may choose not to establish a second RRC connection with the second terminal.

[0141] The first terminal not receiving the second instruction information sent by the second terminal can mean that the first terminal did not receive the second instruction information sent by the second terminal after a second time period following the sending of the first instruction information. The second time period can be preset, determined by the protocol between the second terminal and the first terminal, or determined by the first terminal based on information such as the communication quality of the side link.

[0142] For example, after S320, the first terminal can establish a second radio resource control connection with the second network device. The establishment of the second radio resource control connection may be independent of the execution of S330.

[0143] By establishing a second radio resource control connection, data interruption of the second terminal can be avoided.

[0144] Additionally, the apparatus executing method 300 can determine the connection status of the radio resource control connection between the first terminal and the first network device, and send status indication information to the second terminal. The status indication information includes first status information, second status information, or third status information. The first status information is used to indicate that the connection status is in the process of being established, the second status information is used to indicate that the connection status is in the process of being established, the third status information is used to indicate that the connection status is in the process of being established, and the first terminal is a relay device for the second terminal to access the first network device.

[0145] Specifically, the "establishing" state indicates that a connection is being established or is in the process of being established. The connection state is determined to be in the "establishing" state when the first terminal is switching, the radio resource control connection is being established, or the radio resource control connection is being recovered from a radio link failure (Uu-RLF recovering).

[0146] The connection establishment completion status indicates that the connection has been successfully established or the connection has been established. The connection status is determined to be the connection establishment completion status when the first terminal completes a handover, the radio resource control connection is successfully established, or the radio resource control connection radio link failure recovery (Uu-RLF recovered) is completed.

[0147] The connection establishment failure state indicates that the connection establishment failed or the connection could not be obtained. The connection state is determined to be the connection establishment failure state in the following situations: first terminal device handover failure (HO failure), radio resource control connection establishment failure, radio link failure of the radio resource control connection, failure to recover the radio resource control connection with a radio link failure (Uu-RLF failure), or release of the radio resource control connection.

[0148] For example, when receiving radio resource control release information sent by the first network device, wherein the radio resource control release information is used to indicate the release of the radio resource control connection, the connection status is determined to be the establishment failure status.

[0149] Figure 4 This is a schematic flowchart of a communication method provided in an embodiment of this application. The communication method 400 includes steps S410 to S460.

[0150] An RRC connection is established between the first terminal and the first network device.

[0151] After the first terminal establishes an RRC connection with the first network device, the first network device can send at least one measurement event to the first terminal.

[0152] The first terminal detects the signal of each cell and determines whether the detection result matches at least one measurement event. If the detection result matches any measurement event, step S410 can be performed.

[0153] In S410, the first terminal sends a measurement report to the first network device.

[0154] For example, the measurement report may include measurement events satisfied by the first terminal.

[0155] In S420, the first network device determines that there is no session belonging to the first terminal.

[0156] The at least one measurement event may include at least one of measurement event A2, measurement event A3, measurement event A4, measurement event A5, measurement event A6, measurement event B1, and measurement event B2.

[0157] Measurement event A2 is when the signal quality of the serving cell falls below the corresponding threshold.

[0158] Measurement event A3 is when the signal quality of the neighboring cell begins to be higher than that of the serving cell by a certain offset.

[0159] Measurement event A4 is when the signal quality of the neighboring cell becomes higher than the corresponding threshold.

[0160] Measurement event A5 is when the signal quality of the serving cell becomes lower than threshold 1 and the signal quality of the neighboring cell becomes higher than threshold 2.

[0161] Measurement event A6 indicates that the signal quality of the neighboring cell is now slightly higher than that of the secondary cell (Scell) by a certain offset.

[0162] Measurement event B1 is that the signal quality of the inter-system (Inter-RAT) neighboring cell becomes higher than the corresponding threshold.

[0163] Measurement event B2 indicates that the primary cell (Pcell) signal quality has fallen below threshold 1 and the signal quality of a neighboring cell in another system has risen above threshold 2.

[0164] It should be understood that both the primary cell and the secondary cell are cells covered by the first network device and are used to provide services to the first terminal. The primary cell and the secondary cell correspond to different frequency bands. Neighboring cells are cells other than the serving cell, and the serving cell is the cell covered by the first network device. The serving cell provides services to the first terminal.

[0165] After receiving the measurement report, the first network device can determine whether a session of the first terminal exists. If the first network device determines that no session of the first terminal exists, the first network device can release the RRC context of the first terminal and perform S430. The first network device can release the RRC context of the first terminal, that is, the first access network device disconnects the RRC connection with the first terminal.

[0166] When the first network device determines that no session belongs to the first terminal, it can determine whether a protocol data unit (PDU) session belonging to the first terminal exists. If the first network device determines that no PDU session belongs to the first terminal, the first network device can perform S430 and disconnect the RRC connection with the first terminal.

[0167] In S430, the first network device sends an RRC release message to the first terminal. The RRC release message indicates that the first network device is releasing the RRC connection of the first terminal.

[0168] After the first terminal receives the RRC release information, it enters the RRC idle state (RRC_IDLE) and can perform any of the S440, S450, and S460 operations.

[0169] In S440, the first terminal sends a side link release instruction to the second terminal.

[0170] The sidelink release indication information is used to instruct the second terminal to disconnect the sidelink connection with the first terminal.

[0171] After receiving the sidelink release instruction, the second terminal can disconnect the sidelink connection with the first terminal. That is, the second terminal can release the sidelink context.

[0172] After disconnecting the sidelink connection with the first terminal, the second terminal can perform relay reselection or cell (re)selection. That is, the second terminal can re-determine the relay terminal, or the second terminal can initiate random access to the second network device and establish an RRC connection with the second network device.

[0173] S450 includes S451 to S453.

[0174] In S451, the first terminal can send Uu port RRC release information to the second terminal.

[0175] Uu-port RRC release information is used to indicate that the RRC connection between the first terminal and the first network device has been disconnected. For example, Uu-port RRC release information is used to indicate that the first network device releases the RRC context of the first terminal.

[0176] After receiving the Uu port RRC release information sent by the first terminal, the second terminal can release the side link with the first terminal.

[0177] Alternatively, the second terminal can maintain a side link with the first terminal, that is, maintain a connection with the first terminal.

[0178] In some embodiments, if the second terminal determines that the side link should be maintained, it may send side link maintenance information to the first terminal.

[0179] In S452, the first terminal obtains the response from the second terminal to maintain the side link.

[0180] For example, when the first terminal receives the side link hold information sent by the second terminal, it can be understood that the first terminal has obtained the response from the second terminal to hold the side link.

[0181] For example, a timer can be set in the first terminal. The first terminal can start the timer when sending the Uu port RRC release information. After the timer starts, the countdown ends after a first duration. The first duration can be preset, determined by the protocol between the second terminal and the first terminal, or determined by the first terminal based on information such as the communication quality of the sidelink. When the timer ends, the first terminal can determine whether the sidelink connection with the second terminal remains open. If it is determined that the sidelink connection remains open, the first terminal receives a response from the second terminal indicating that the sidelink connection has been maintained. That is, at the detection time point of the preset duration after the Uu port RRC release information is sent, if the first terminal determines that the sidelink connection with the second terminal has not been disconnected, the first terminal receives a response from the second terminal indicating that the sidelink connection has been maintained.

[0182] In S453, the first terminal establishes an RRC connection with the second network device.

[0183] After the first terminal connects to the second network device, it can stay in the cell covered by the second network device.

[0184] It should be understood that the second network device can be the first network device or other network devices besides the first network device.

[0185] When the second network device is the first network device, the cell where the first terminal camps after random access can be a different cell than the cell served by the first terminal before S410.

[0186] After the first terminal establishes an RRC connection with the second network device, the first terminal acts as a relay terminal for the second terminal, and can relay data between the second terminal and the second network device.

[0187] After S451, if the first terminal does not receive a response from the second terminal to maintain the side link, the first terminal can release the side link with the second terminal.

[0188] S460 includes S461 to S463.

[0189] In S461, the first terminal can send status indication information to the second terminal.

[0190] If the RRC connection status between the first terminal and the network device changes, the first terminal can send status indication information to the second terminal.

[0191] The RRC connection status between the first terminal and the network device can be any one of the following: connection established, connection completed, or connection unavailable.

[0192] Prior to S410, the RRC connection status between the first terminal and the first network device was "connection complete". The first network device could send an RRC release message to the first terminal and release the RRC connection with the first terminal. In S410, the first terminal receives the RRC release message sent by the first network device, determines that the RRC connection status between the first terminal and the first network device has changed to "connection cannot be obtained", and proceeds to S461.

[0193] Alternatively, upon receiving RRC release information from the first network device, the first terminal can detect the RRC connection status between the first terminal and the first network device. If the RRC connection status between the first terminal and the first network device is detected as "connection unavailable," the first terminal can proceed to step S461.

[0194] In S462, the first terminal obtains the response from the second terminal to maintain the side link.

[0195] Similar to S452, if the first terminal receives the sidelink hold information sent by the second terminal, or if the first terminal determines at a preset detection time point after sending the status indication information in S461 that the sidelink between it and the second terminal has not been disconnected, then the first terminal obtains the response from the second terminal to hold the sidelink. Afterwards, the first terminal can proceed to S463.

[0196] In S463, the first terminal establishes an RRC connection with the second network device.

[0197] After S461, if the first terminal does not receive a response from the second terminal to maintain the side link, the first terminal can release the side link with the second terminal.

[0198] Optionally, after S440, the first terminal may not release the side link and, after receiving the response from the second terminal to maintain the side link, establish an RRC connection with the second network device.

[0199] Figure 5 This is a schematic flowchart of a communication method provided in an embodiment of this application.

[0200] When the first terminal acts as a relay device for the second terminal to access the network equipment, the first terminal can send event information to the second terminal to indicate events related to the Radio Resource Control (RRC) connection between the first terminal and the network equipment. For example, after the first terminal confirms that an RLF has occurred in the RRF connection with the network equipment, it can send event information to the second terminal to indicate that the RRF has occurred. In other words, different times can correspond to different event information.

[0201] The second terminal may perform the same operation after receiving different event information. For example, event 1 is a handover failure of the first terminal, and event 2 is a Radio Resource Control (RLF) failure between the first terminal and the network device. The event information corresponding to events 1 and 2 is different. However, after receiving the event information corresponding to event 1 and the event information corresponding to event 2, the second terminal can both perform the operation of releasing the sidelink with the first terminal.

[0202] In other words, the first terminal sends event information to the second terminal to indicate events related to the radio resource control connection between the first terminal and the network device. Since there are many events related to the radio resource control connection between the first terminal and the network device, more bits are needed to distinguish different event information, leading to information redundancy. To solve this problem, this application provides a communication method 500. Method 500 includes steps S510 to S520.

[0203] In S510, the connection status of the radio resource control connection between the first terminal and the network device is determined.

[0204] Specifically, when the first terminal is switching, the radio resource control connection is being established, or the radio resource control connection that has experienced a radio link failure is being restored, the connection state can be determined to be the state of being established.

[0205] When the first terminal completes the handover, the radio resource control connection is established, or the radio link failure recovery of the radio resource control connection is completed, the connection status can be determined to be the established status.

[0206] If the first terminal device fails to switch over, the wireless resource control connection fails to establish, the wireless link of the wireless resource control connection fails, the recovery of the wireless resource control connection that has experienced a wireless link failure fails, or the wireless resource control connection is released, the connection status can be determined to be the establishment failure status.

[0207] In S520, status indication information is sent to the second terminal. The status indication information includes first status information, second status information, or third status information. The first status indication information is used to indicate that the connection status is in the process of being established, the second status information is used to indicate that the connection status is established successfully, and the third status information is used to indicate that the connection status is established unsuccessfully. The first terminal is a relay device for the second terminal to access the network device.

[0208] For events corresponding to the same connection status of the radio resource control (RFC) connection between the first terminal and the network device, the operation of the second terminal can be the same. Through method 500, the first terminal sends status indication information to the second terminal to indicate the connection status of the RRC connection between the first terminal and the network device. The number of RRC connection statuses is less than the number of events related to the RRC connection, thereby saving information bits, avoiding information redundancy, and simplifying the processing of both the first and second terminals.

[0209] It should be understood that the first terminal may periodically or non-periodically detect the status of the radio resource control connection between the first terminal and the network device, determine the connection status of the radio resource control connection between the first terminal and the network device, and send status indication information to the second terminal.

[0210] Alternatively, the first terminal may send status indication information to the second terminal if it determines that the connection status of the radio resource control connection between the first terminal and the network device has changed.

[0211] Specifically, when the first terminal receives the radio resource control release information sent by the first network device, the connection status can be determined to be the establishment failure status. The radio resource control release information is used to indicate the release of the radio resource control connection.

[0212] The Radio Resource Control (RRC) release message indicates a change in the connection status of the RRC connection.

[0213] After receiving the Radio Resource Control Release (RRC) signal sent by the first network device, the first terminal can establish a second RRC connection with the second network device. The second RRC connection is used for the second terminal to access the second network device.

[0214] For example, after receiving second indication information sent by the second terminal, the first terminal may establish a second radio resource control connection with the second network device. The second indication information is used to instruct the maintenance of the side link.

[0215] The second instruction information can be understood as a response to the first instruction information.

[0216] For example, the first terminal can establish an RRC connection with the second network device if the side link is not disconnected at the detection time point, and the detection time point includes a time point after the first indication information is sent.

[0217] Figure 6This is a schematic flowchart illustrating a communication method provided in an embodiment of this application. The communication method 600 includes steps S610 to S630.

[0218] In S610, it is determined that there is no session belonging to the first terminal.

[0219] The first network device can determine whether a session belonging to the first terminal exists between the first terminal and the first network device. It can also send the same or different Radio Resource Control (RRC) reconfiguration messages to the first terminal based on the existence of such a session. The first terminal acts as a relay device for the second terminal to access the first network device, and the first terminal and the second terminal communicate via a side link. A first RRC connection exists between the first terminal and the first network device.

[0220] For example, the first network device may periodically determine whether a session belonging to the first terminal exists. Alternatively, the first network device may determine whether a session belonging to the first terminal exists after receiving an indication message, which instructs the first network device to determine whether a session belonging to the first terminal exists. Alternatively, the first network device may determine whether a session belonging to the first terminal exists after determining that the first terminal meets the handover conditions; this embodiment of the application is not limited in this respect.

[0221] When the first network device determines whether a session belonging to the first terminal exists, it can determine whether a PDU session of the first terminal exists.

[0222] In some embodiments, after determining that there is no session belonging to the first terminal, the first network device may execute step S620.

[0223] In other embodiments, after determining that there is no session belonging to the first terminal, the first network device may not execute step S620 and may maintain the first RRC connection with the first terminal. That is, when there is no session belonging to the first terminal, the first network device may not send an RRC reconfiguration message or handover indication information to the first terminal if the handover conditions are met, thereby allowing the second terminal to continue to maintain a connection with the first network device through the first terminal and avoiding data transmission interruption.

[0224] In S620, the first RRC reconfiguration message is sent to the first terminal.

[0225] When the first network device determines that there is no session belonging to the first terminal between the first terminal and the first network device, the first network device may send a first RRC reconfiguration message (i.e., a first radio resource control reconfiguration message) to the first terminal. The first RRC reconfiguration message includes information indicating at least one unmeasurable cell and / or at least one measurable cell covered by the first network device.

[0226] For example, at least one unmeasurable cell can be an unmeasurable cell covered by the first network device, or it can be another unmeasurable cell. The other unmeasurable cells are unmeasurable cells covered by network devices other than the first network device.

[0227] For example, the information in the first RRC reconfiguration message indicating at least one unmeasurable cell can be represented as an unmeasurable cell blacklist, and the information in the first RRC reconfiguration message indicating at least one measurable cell covered by the first network device can be represented as a measurable cell whitelist. In other words, the first RRC reconfiguration message may include a measurable cell whitelist and / or an unmeasurable cell blacklist.

[0228] In some embodiments, when the first network device determines that a session belonging to the first terminal exists between the first terminal and the first network device, the first network device may send a second RRC reconfiguration message (i.e., a second radio resource control reconfiguration message) to the first terminal. The second RRC reconfiguration message includes information indicating the cells and / or other cells covered by the first network device.

[0229] For example, the second RRC reconfiguration message may include any one or more of the following: at least one measurement event, a whitelist of measurable cells, or a blacklist of unmeasurable cells. The whitelist of measurable cells in the second RRC reconfiguration message includes at least one measurable cell and / or other measurable cells covered by the first network device. Other measurable cells are measurable cells covered by network devices other than the first network device. The blacklist of unmeasurable cells in the second RRC reconfiguration message includes at least one unmeasurable cell, which may be an unmeasurable cell covered by the first network device or other unmeasurable cells. Other unmeasurable cells are unmeasurable cells covered by network devices other than the first network device.

[0230] For example, at least one measurement event in the second RRC reconfiguration message may include: the serving cell signal quality becomes higher than a corresponding threshold; the serving cell signal quality becomes lower than a corresponding threshold; the neighboring cell signal quality begins to be higher than the serving cell signal quality by a certain offset; the neighboring cell signal quality becomes higher than a corresponding threshold; the serving cell signal quality becomes lower than threshold 1 and the neighboring cell signal quality becomes higher than threshold 2; the neighboring cell signal quality begins to be higher than the secondary cell signal quality by a certain offset, etc., which are not limited in this application embodiment.

[0231] In some embodiments, if the first network device determines at a first moment that a session belonging to the first terminal exists, and the first network device determines at a second moment that a session belonging to the first terminal does not exist, then the first network device may send a first RRC reconfiguration message to the first terminal at the second moment. The first moment and the second moment are not the same, and the first moment is earlier than the second moment.

[0232] In other embodiments, if the first network device determines at a third time that no session belonging to the first terminal exists, and the first network device determines at a fourth time that a session belonging to the first terminal exists, then the first network device may send a second RRC reconfiguration message to the first terminal at the fourth time. The third time and the fourth time are different, and the third time is earlier than the fourth time.

[0233] In S630, signal measurements are performed based on the first RRC reconfiguration message.

[0234] After receiving the first RRC reconfiguration message from the first network device, the first terminal can perform signal measurement based on the first RRC reconfiguration message.

[0235] For example, if the first RRC reconfiguration message includes information indicating at least one measurable cell covered by the first network device, the first terminal can measure the signal strength of each of the at least one measurable cells.

[0236] For example, if the first RRC reconfiguration message includes information indicating at least one unmeasurable cell, the first terminal may not need to measure the signal strength of the cells included in the at least one unmeasurable cell. In this case, the first terminal may also measure the signal strength of cells other than the at least one unmeasurable cell.

[0237] In some embodiments, after receiving a second RRC reconfiguration message from a first network device, the first terminal can perform signal measurement based on the second RRC reconfiguration message.

[0238] For example, if the second RRC reconfiguration message includes at least one measurement event, the first terminal can perform measurements based on the at least one measurement event. For instance, if one of the at least one measurement events is measurement event A3, the first terminal can measure the signal strength of the serving cell and cells outside the serving cell.

[0239] For example, if the second RRC reconfiguration message includes a measurable cell whitelist, the first terminal can measure the signal strength of the cells included in the measurable cell whitelist.

[0240] For example, if the second RRC reconfiguration message includes a blacklist of unmeasurable cells, the first terminal may choose not to measure the signal strength of the cells included in the blacklist. In this case, the first terminal may also measure the signal strength of cells other than those included in the blacklist.

[0241] In some embodiments, the first terminal may send a first measurement report to the first network device based on the measured signal quality. This first measurement report is determined based on either a first RRC reconfiguration message or a second RRC reconfiguration message.

[0242] In other embodiments, the first network device may determine whether it needs to send a handover instruction to the first terminal based on a first measurement report received from the first terminal.

[0243] The first network device can send the same or different RRC reconfiguration messages to the first terminal depending on whether a session belonging to the first terminal exists. When no session belonging to the first terminal exists, the first RRC reconfiguration message sent by the first network device to the first terminal can maintain the connection between the first terminal and the first network device, thereby allowing the second terminal to transmit data to the first network device through the first terminal and avoiding data interruption for the second terminal.

[0244] Figure 7 This is a schematic flowchart of a communication method provided in an embodiment of this application. The communication method 700 includes steps S710 to S740.

[0245] In S710, it is determined whether a session belonging to the first terminal exists.

[0246] A first radio resource control (RRC) connection exists between the first network device and the first terminal. The first terminal serves as a relay device for the second terminal to access the first network device, and the first terminal and the second terminal communicate via a side link.

[0247] For example, the first network device may periodically determine whether a session belonging to the first terminal exists. Alternatively, the first network device may determine whether a session belonging to the first terminal exists after a preset condition is met. The preset condition may include: receiving indication information, which indicates whether a session belonging to the first terminal exists; or determining that the first terminal meets handover conditions, etc., which are not limited in this embodiment.

[0248] The specific implementation method of the first network device determining that there is no session belonging to the first terminal is similar to step S610, and will not be repeated here.

[0249] In S720, a first RRC reconfiguration message or a second RRC reconfiguration message is sent to the first terminal.

[0250] When it is determined that no session belongs to the first terminal, the first network device may send a first RRC reconfiguration message to the first terminal. This first RRC reconfiguration message includes information indicating at least one unmeasurable cell and / or at least one measurable cell covered by the first network device. The specific implementation of the first network device sending the first RRC reconfiguration message to the first terminal is similar to step S620 and will not be repeated here.

[0251] When it is determined that there is no session belonging to the first terminal, the first network device may send a second RRC reconfiguration message to the first terminal. The second RRC reconfiguration message includes information indicating the cells covered by the first network device and / or other cells, where other cells are cells outside the cells covered by the first network device.

[0252] For example, the second RRC reconfiguration message includes one or more of the following: at least one measurement event, a measurable cell whitelist, or a non-measurable cell blacklist. The measurable cell whitelist includes at least one measurable cell within or outside the coverage area of ​​the first network device, and the non-measurable cell blacklist includes at least one non-measurable cell.

[0253] In step S730, the first terminal performs signal measurement based on either the first RRC reconfiguration message or the second RRC reconfiguration message. Step S730 is similar to step S630 and will not be described again here.

[0254] In S740, a first measurement report is sent to the first network device.

[0255] The first terminal can perform signal measurements based on a first RRC reconfiguration message or a second RRC reconfiguration message, and send a first measurement report to the first network device. The first measurement report may include information indicating the signal quality measured by the first terminal.

[0256] For example, if the first RRC reconfiguration message includes at least one measurable cell covered by the first network device, then the first measurement report may include the signal quality of each of the at least one measurable cell covered by the first network device.

[0257] For example, if the first RRC reconfiguration message includes at least one unmeasurable cell, the first measurement report may include the signal quality of cells other than those included in the at least one unmeasurable cell.

[0258] For example, if the second RRC reconfiguration message includes at least one measurement event, the first measurement report may include the measurement event whose measurement result matches the measurement event among the at least one measurement event. Alternatively, the first measurement report may also include the target cell or target base station that makes the measurement result match the measurement event. The target cell is a cell covered by the target base station. Alternatively, the first measurement report may also include the signal quality of the cell involved in the at least one measurement event.

[0259] For example, if the second RRC reconfiguration message includes a measurable cell whitelist, the first measurement report may include the signal quality of the cells included in the measurable cell whitelist.

[0260] For example, if the second RRC reconfiguration message includes a blacklist of unmeasurable cells, the first measurement report may include the signal quality of cells other than those included in the unmeasurable cell blacklist.

[0261] In some embodiments, after receiving a first measurement report from a first terminal, the first network device may determine that the first terminal meets the handover conditions and send handover instruction information to the first terminal.

[0262] For example, if the first network device determines that there is no session belonging to the first terminal, the first network device can determine a list of target cells or a list of target frequencies that meet the handover conditions based on the received first measurement report, and determine a first cell or a first frequency from the list of target cells or target frequencies. The cells or frequencies included in the list of target cells or target frequencies are cells or frequencies covered by the first network device. The first network device can send handover instruction information to the first terminal. The handover instruction information is used to instruct the first terminal to hand over from the current serving cell to the first cell. The first cell is the cell with the best signal quality among the cells in the target cell list that can provide services to the first terminal. The first frequency is the frequency with the best signal quality among the frequency points in the target frequency list whose corresponding cells can provide services to the first terminal. The cell corresponding to the first frequency can be the first cell.

[0263] For example, when the first network device determines that a session belonging to the first terminal exists, the first network device can determine a target cell list or a target frequency list that meets the handover conditions based on the received first measurement report. The cells or frequencies included in the target cell list or target frequency list are cells or frequencies covered by the first network device, or cells or frequencies covered by network devices other than the first network device. The first network device can also determine a first cell or a first frequency from the target cell list or target frequency list. The first cell can be a cell covered by the first network device, or a cell covered by network devices other than the first network device. The first cell is the cell with the best signal quality among the cells in the target cell list that can provide services to the first terminal. The first frequency is the frequency with the best signal quality among the frequency points in the target frequency list whose corresponding cells can provide services to the first terminal. The cell corresponding to the first frequency can be the first cell.

[0264] If the first cell is a cell covered by the first network device, the first network device can send a handover instruction to the first terminal. The handover instruction is used to instruct the first terminal to hand over from the current serving cell to the first cell.

[0265] If the first cell is a cell covered by a network device other than the first network device, and the network device to which the first cell belongs is the second network device, then the first network device can send a handover request message to the second network device to assist the first terminal in switching from its current serving cell to the first cell covered by the second network device.

[0266] In some embodiments, after the first network device sends a handover indication to the first terminal, the first terminal can establish a second RRC connection with the second network device. The first terminal acts as a relay terminal for the second terminal, relaying data between the second terminal and the second network device. After accessing the second network device, the first terminal can camp on a cell covered by the second network device.

[0267] The process of a first terminal switching from its current serving cell to the first cell can be a coverage-based intra-frequency handover process or a coverage-based inter-frequency handover process.

[0268] When the signal ranges of the current serving cell and the first cell partially overlap, and the frequency points of the current serving cell and the first cell are the same, the process of the first terminal switching from the current serving cell to the first cell is a coverage-based same-frequency handover.

[0269] In some embodiments of coverage-based intra-frequency handover, the first network device may send a first RRC reconfiguration message to the first terminal when it determines that no session belongs to the first terminal. The first RRC reconfiguration message includes information indicating at least one unmeasurable cell and / or at least one measurable cell covered by the first network device.

[0270] Alternatively, the first network device may send a second RRC reconfiguration message to the first terminal upon determining that a session belonging to the first terminal exists. The second RRC reconfiguration message includes one or more of the following: at least one measurement event, a whitelist of measurable cells, or a blacklist of unmeasurable cells. For example, the second RRC reconfiguration message may include measurement event A3.

[0271] For example, after receiving the first RRC reconfiguration message or the second RRC reconfiguration message, the first terminal can perform signal measurements based on the first RRC reconfiguration message or the second RRC reconfiguration message. Furthermore, the first terminal can send a first measurement report to the first network device. This first measurement report is determined based on the first RRC reconfiguration message or the second RRC reconfiguration message. For instance, if the second RRC reconfiguration message includes measurement event A3, the first measurement report can include at least one target cell or target frequency point that satisfies measurement event A3.

[0272] For example, after receiving a first measurement report from a first terminal, the first network device can generate a target cell list or a target frequency list based on the first measurement report. The first network device can determine a first cell from the target cell list or the target frequency list. If there is no session belonging to the first terminal, the first cell is a cell covered by the first network device. If there is a session belonging to the first terminal, the first cell can be a cell covered by the first network device, or it can be a cell covered by a network device other than the first network device.

[0273] When there is partial overlap in the signal range between the current serving cell and the first cell, and the frequency points of the current serving cell and the first cell are different, the process of the first terminal switching from the current serving cell to the first cell is a coverage-based inter-frequency handover.

[0274] In some embodiments of coverage-based inter-frequency handover, the first network device may receive a second measurement report from the first terminal before executing S710. That is, method 700 may also include S701.

[0275] In S701, the first terminal sends a second measurement report to the first network device.

[0276] The second measurement report includes information indicating the quality of the signal obtained from the first terminal measurement.

[0277] For example, the second measurement report can be determined based on the RRC configuration information most recently received by the first terminal. The RRC configuration information most recently received by the first terminal includes any of the following: RRC configuration information received when the first terminal establishes a connection with the first network device, a first RRC reconfiguration message, or a second RRC reconfiguration message. The RRC configuration information received when the first terminal establishes a connection with the first network device may include at least one measurement event.

[0278] For example, if the most recently received RRC configuration information by the first terminal is the RRC configuration information received when the first terminal established a connection with the first network device, and the RRC configuration information received when the first terminal established a connection with the first network device includes measurement event A2, then the second measurement report may include information indicating that the reference signal receiving power (RSRP) or reference signal receiving quality (RSRQ) of the second cell or the second frequency point meets the measurement event A2. The second cell or the second frequency point may be a cell or frequency point covered by the first network device, or it may be a cell or frequency point covered by a network device other than the first network device.

[0279] For example, if the RRC configuration information recently received by the first terminal is a first RRC reconfiguration message or a second RRC reconfiguration message, the second measurement report can be similar to the first measurement report.

[0280] In some embodiments of inter-frequency handover based on coverage, the first network device can determine whether a session belonging to the first terminal exists after receiving a second measurement report from the first terminal. Alternatively, the first network device can periodically determine whether a session belonging to the first terminal exists, etc., and this application embodiment is not limited in this respect.

[0281] In some embodiments of coverage-based inter-frequency handover, the first network device may send a first RRC reconfiguration message to the first terminal when it determines that no session belongs to the first terminal. The first RRC reconfiguration message includes information indicating at least one unmeasurable cell and / or at least one measurable cell covered by the first network device.

[0282] Alternatively, the first network device may send a second RRC reconfiguration message to the first terminal upon determining that a session belonging to the first terminal exists. The second RRC reconfiguration message includes one or more of the following: at least one measurement event, a measurable cell whitelist, or an unmeasurable cell blacklist. For example, the second RRC reconfiguration message may include measurement event A5 and measurement event A1, or the second RRC reconfiguration message may include measurement event A3 and measurement event A1. Measurement event A1 is when the signal quality of the serving cell becomes higher than a corresponding threshold.

[0283] In some embodiments of coverage-based inter-frequency handover, when the first network device receives the second measurement report and determines that a session belonging to the first terminal exists, it can determine the specific content of the second RRC reconfiguration message based on the configuration information of the cell or frequency point involved in the second measurement report.

[0284] For example, when the second measurement report includes information indicating that the RSRP or RSRQ of the second cell or the second frequency point meets measurement event A2, and it is determined that a session belonging to the first terminal exists, the first network device can determine at least one measurement event included in the second RRC reconfiguration message based on the configuration information of the second cell or the second frequency point.

[0285] If the configuration information for the second cell or the second frequency point is event A5, then the second RRC reconfiguration message may include measurement event A5 and measurement event A1. If the configuration information for the second cell or the second frequency point is event A3, then the second RRC reconfiguration message may include measurement event A3 and measurement event A1.

[0286] Optionally, the configuration information of the second cell or the second frequency point can be information stored in the first network device. Alternatively, the configuration information of the second cell or the second frequency point can be information sent by the first terminal to the first network device; this embodiment of the application is not limited in this respect.

[0287] For example, after receiving the first RRC reconfiguration message or the second RRC reconfiguration message, the first terminal can perform signal measurements based on the first RRC reconfiguration message or the second RRC reconfiguration message. Furthermore, the first terminal can send a first measurement report to the first network device. This first measurement report is determined based on the first RRC reconfiguration message or the second RRC reconfiguration message. For instance, if the second RRC reconfiguration message includes measurement event A5 and measurement event A1, the first measurement report can include at least one target cell or target frequency point that satisfies measurement event A5 and measurement event A1.

[0288] For example, after receiving a first measurement report from a first terminal, the first network device can generate a target cell list or a target frequency list based on the first measurement report. The first network device can determine a first cell from the target cell list or the target frequency list. If there is no session belonging to the first terminal, the first cell is a cell covered by the first network device. If there is a session belonging to the first terminal, the first cell can be a cell covered by the first network device, or it can be a cell covered by a network device other than the first network device.

[0289] In other embodiments of coverage-based inter-frequency handover, the first network device may, upon receiving a second measurement report from the first terminal and determining that no session belongs to the first terminal, refrain from sending a first RRC reconfiguration message to the first terminal and maintain the first RRC connection with the first terminal. In this case, the second terminal can continue to maintain a connection with the first network device through the first terminal, thereby avoiding data transmission interruption.

[0290] When a session belonging to the first terminal exists, the first network device can send a second RRC reconfiguration message to the first terminal, enabling the first terminal to perform signal measurements based on the second RRC reconfiguration message and determine whether a cell with better signal quality exists. The first network device can also send a first RRC reconfiguration message to the first terminal when no session belonging to the first terminal exists, maintaining the connection between the first terminal and the first network device and thus preventing data transmission interruption from the second terminal.

[0291] Figure 8 This is a schematic structural diagram of a communication device provided in an embodiment of this application.

[0292] The communication device 800 includes a receiving module 810 and a transmitting module 820.

[0293] The receiving module 810 is configured to receive radio resource control release information sent by the first network device, the radio resource control release information being used to instruct the release of the first radio resource control connection between the first terminal and the first network device. The first terminal may include device 800.

[0294] The sending module 820 is used to send first indication information to the second terminal, the first terminal being a relay device for the second terminal to access the first network device, the first indication information being used to indicate the release of the side link between the first terminal and the second terminal, or to indicate that the first radio resource control connection is released, or to indicate that the state of the first radio resource control connection is a connection failure state.

[0295] Optionally, the communication device 800 further includes an establishment module for establishing a second radio resource control connection with the second network device, the second radio resource control connection being used by the second terminal to access the second network device.

[0296] Optionally, the receiving module 810 is further configured to receive second indication information sent by the second terminal, the second indication information being used to indicate maintaining the side link.

[0297] Optionally, the module is specifically used to establish an RRC connection with the second network device when the side link is not disconnected at the detection time point, wherein the detection time point includes a time point after the first indication information is sent for a first duration.

[0298] Optionally, the wireless resource control release information is received when the first terminal meets the handover conditions and there is no session belonging to the first terminal between the first terminal and the first network device.

[0299] Optionally, the communication device 800 further includes a processing module, which is used to determine the connection status of the first radio resource control connection.

[0300] The sending module 820 is further configured to send status indication information to the second terminal. The status indication information includes first status information, second status information, or third status information. The first status information is used to indicate that the connection status is in the process of being established, the second status information is used to indicate that the connection status is in the process of being established, and the third status information is used to indicate that the connection status is in the process of being established.

[0301] Optionally, the processing module is specifically configured to determine the connection state as the "establishing state" when the first terminal is switching, the first radio resource control connection is being established, or the first radio resource control connection that has experienced a radio link failure is being restored.

[0302] The processing module is specifically used to determine the connection status as the established status when the first terminal completes the handover, the first radio resource control connection is established, or the first radio resource control connection fails and is recovered.

[0303] The processing module is specifically used to determine the connection status as the establishment failure status when the first terminal device fails to switch, the first radio resource control connection fails to establish, the first radio resource control connection experiences a radio link failure, the recovery of the first radio resource control connection that has experienced a radio link failure fails, or the first radio resource control connection is released.

[0304] Figure 9 This is a schematic structural diagram of a communication device provided in an embodiment of this application.

[0305] The communication device 900 includes a processing module 910 and a transceiver module 920.

[0306] The processing module 910 is used to determine the connection status of the first radio resource control connection between the first terminal and the first network device. The communication device 900 may be located in the first terminal.

[0307] The transceiver module 920 is used to send status indication information to the second terminal. The status indication information includes first status information, second status information, or third status information. The first status information is used to indicate that the connection status is in the process of being established, the second status information is used to indicate that the connection status is established successfully, and the third status information is used to indicate that the connection status is established unsuccessfully. The first terminal is a relay device for the second terminal to access the first network device.

[0308] Optionally, the processing module 910 is specifically configured to determine the connection state as the "establishing state" when the first terminal is switching, the first radio resource control connection is being established, or the first radio resource control connection that has experienced a radio link failure is being restored.

[0309] The processing module 910 is specifically used to determine the connection status as the established status when the first terminal completes the handover, the first radio resource control connection is established, or the first radio resource control connection fails and recovers.

[0310] The processing module 910 is specifically used to determine the connection status as the establishment failure status when the first terminal device fails to switch, the first radio resource control connection fails to establish, the first radio resource control connection experiences a radio link failure, the recovery of the first radio resource control connection that has experienced a radio link failure fails, or the first radio resource control connection is released.

[0311] Optionally, the processing module 910 is specifically configured to, upon receiving the radio resource control release information sent by the first network device, determine that the connection status is the establishment failure status, wherein the radio resource control release information is used to indicate the release of the first radio resource control connection.

[0312] Optionally, the processing module 910 is further configured to establish a second radio resource control connection with the second network device, the second radio resource control connection being used by the second terminal to access the second network device.

[0313] Optionally, the transceiver module 920 is configured to further include: receiving second indication information sent by the second terminal, the second indication information being used to indicate maintaining the side link.

[0314] Optionally, the processing module 910 is specifically used to establish an RRC connection with the second network device when the side link is not disconnected at the detection time point, wherein the detection time point includes a time point after the first indication information is sent for a first duration.

[0315] Optionally, the processing module 910 is specifically configured to receive the wireless resource control release information when the first terminal meets the handover conditions and there is no session belonging to the first terminal between the first terminal and the first network device.

[0316] In some embodiments, the transceiver module 920 can receive a first radio resource control reconfiguration message from the first network device when there is no session belonging to the first terminal between the first terminal and the first network device, and can also receive a second radio resource control reconfiguration message from the first network device when a session belonging to the first terminal exists. The transceiver module 920 can also send a first measurement report or a second measurement report to the first network device. The transceiver module 920 can execute step S620 in the method of FIG6 or... Figure 7 Steps S701, S720, and S740 in the method.

[0317] In some embodiments, the processing module 910 may perform signal measurement based on a first Radio Resource Control (RRC) reconfiguration message or a second RRC reconfiguration message. The processing module 910 may execute... Figure 6 Step S630 in the method, or Figure 7 Step S730 in the method.

[0318] Figure 10 This is a schematic structural diagram of a communication device provided in an embodiment of this application.

[0319] The communication device 1000 includes a processing module 1010 and a transceiver module 1020.

[0320] The processing module 1010 is used to determine that the first terminal meets the handover conditions and that there is no session belonging to the first terminal between the first terminal and the first network device. The first terminal is a relay device for the second terminal to access the first network device, and a first radio resource control connection exists between the first terminal and the first network device.

[0321] The transceiver module 1020 is used to send radio resource control release information to the first terminal. The radio resource control release information is used to indicate the release of the first radio resource control connection between the first terminal and the first network device.

[0322] In some embodiments, the transceiver module 1020 is further configured to receive a measurement report from the first terminal. The measurement report includes information indicating the signal quality measured by the first terminal.

[0323] In some embodiments, the processing module 1010 is further configured to determine, based on a received measurement report from the first terminal, that the first terminal meets the handover conditions. The processing module 1010 can also be configured to release the first radio resource control connection between the first terminal and the first network device.

[0324] In some embodiments, the processing module 1010 can determine whether a session belonging to the first terminal exists between the first terminal and the first network device, wherein the first terminal is a relay device for the second terminal to access the first network device. The processing module 1010 can execute... Figure 6 Step S610 in the method or Figure 7 Step S710 in the method.

[0325] In some embodiments, the transceiver module 1020 can send a first radio resource control reconfiguration message to the first terminal when no session belonging to the first terminal exists, and can also send a second radio resource control reconfiguration message to the first terminal when a session belonging to the first terminal exists. The transceiver module 1020 can also receive a first measurement report or a second measurement report from the first terminal. The transceiver module 1020 can perform... Figure 6 Step S620 in the method, or Figure 7 Steps S701, S720, and S740 in the method.

[0326] Figure 11 This is a schematic structural diagram of a communication device provided in an embodiment of this application.

[0327] The communication device 2000 includes at least one processor 2010 and a communication interface 2020. The communication interface 2020 is used for the terminal to interact with other communication devices, and when program instructions are executed in the at least one processor, the terminal performs the communication method described above. A first terminal may include the communication device 2000.

[0328] Specifically, in some embodiments, at least one processor 2010 may be used to receive radio resource control release information sent by a first network device via a communication interface 2020, the radio resource control release information being used to indicate the release of a first radio resource control connection between a first terminal and the first network device.

[0329] At least one processor 2010 may also be used to send first indication information to the second terminal via communication interface 2020, wherein the first terminal is a relay device for the second terminal to access the first network device, and the first indication information is used to indicate the release of the side link between the first terminal and the second terminal, or to indicate that the first radio resource control connection is released, or to indicate that the state of the first radio resource control connection is a connection failure state.

[0330] Optionally, at least one processor 2010 is further configured to establish a second radio resource control connection with a second network device, the second radio resource control connection being used by the second terminal to access the second network device.

[0331] Optionally, at least one processor 2010 is further configured to receive second indication information sent by the second terminal via the communication interface 2020, the second indication information being used to indicate maintaining the side link.

[0332] Optionally, at least one processor 2010 is specifically configured to establish an RRC connection with the second network device if the side link is not disconnected at the detection time point, wherein the detection time point includes a time point after the first indication information is sent for a first duration.

[0333] Optionally, the wireless resource control release information is received when the first terminal meets the handover conditions and there is no session belonging to the first terminal between the first terminal and the first network device.

[0334] Optionally, at least one processor 2010 is specifically configured to determine the connection status of the first radio resource control connection.

[0335] At least one processor 2010 is further configured to send status indication information to a second terminal via a communication interface 2020, the status indication information including first status information, second status information or third status information, the first status information indicating that the connection status is in the process of being established, the second status information indicating that the connection status is in the process of being established, and the third status information indicating that the connection status is in the process of being established.

[0336] Optionally, at least one processor 2010 is specifically configured to determine the connection state as the establishing state when the first terminal is switching, the first radio resource control connection is being established, or the first radio resource control connection that has experienced a radio link failure is being restored.

[0337] At least one processor 2010 is specifically configured to determine the connection status as the established state when the first terminal completes the handover, the first radio resource control connection is established, or the first radio resource control connection radio link failure recovery is completed.

[0338] At least one processor 2010 is specifically configured to determine the connection state as the establishment failure state when the first terminal device fails to switch, the first radio resource control connection fails to establish, the first radio resource control connection experiences a radio link failure, the recovery of the first radio resource control connection that has experienced a radio link failure fails, or the first radio resource control connection is released.

[0339] In other embodiments, at least one processor 2010 is configured to determine the connection status of a first radio resource control connection between a first terminal and a first network device.

[0340] The communication interface 2020 is used to send status indication information to the second terminal. The status indication information includes first status information, second status information, or third status information. The first status information is used to indicate that the connection status is in the process of being established, the second status information is used to indicate that the connection status is in the process of being established, and the third status information is used to indicate that the connection status is in the process of being established. The first terminal is a relay device for the second terminal to access the first network device.

[0341] Optionally, at least one processor 2010 is configured to determine the connection state as the establishing state when the first terminal is switching, the first radio resource control connection is being established, or the first radio resource control connection is being restored after a radio link failure.

[0342] At least one processor 2010 is configured to determine the connection status as the established state when the first terminal completes the handover, the first radio resource control connection is established, or the first radio resource control connection radio link failure recovery is completed.

[0343] At least one processor 2010 is configured to determine the connection state as the establishment failure state when the first terminal device fails to switch, the first radio resource control connection fails to establish, the first radio resource control connection experiences a radio link failure, the recovery of the first radio resource control connection that has experienced a radio link failure fails, or the first radio resource control connection is released.

[0344] Optionally, at least one processor 2010 is configured to, upon receiving radio resource control release information sent by the first network device, determine that the connection state is the establishment failure state, wherein the radio resource control release information is used to indicate the release of the first radio resource control connection.

[0345] Optionally, at least one processor 2010 is configured to establish a second radio resource control connection with a second network device, the second radio resource control connection being used by the second terminal to access the second network device.

[0346] Optionally, the communication interface 2020 is further configured to include the method in the following ways: receiving second indication information sent by the second terminal, the second indication information being used to indicate maintaining the side link.

[0347] Optionally, at least one processor 2010 is configured to establish an RRC connection with the second network device if the side link is not disconnected at the detection time point, wherein the detection time point includes a time point after the first indication information is sent for a first duration.

[0348] Optionally, the wireless resource control release information is received when the first terminal meets the handover conditions and there is no session belonging to the first terminal between the first terminal and the first network device.

[0349] In some embodiments, at least one processor 2010 may be configured to receive a first radio resource control reconfiguration message from the first network device when there is no session belonging to the first terminal between the first terminal and the first network device via a communication interface 2020.

[0350] In some embodiments, at least one processor 2010 may also be configured to, using a communication interface 2020, receive a second radio resource control reconfiguration message from a first network device when a session belonging to the first terminal exists.

[0351] In some embodiments, at least one processor 2010 may also be used to perform signal measurement based on a first radio resource control reconfiguration message or a second radio resource control reconfiguration message.

[0352] In some embodiments, at least one processor 2010 may also be used to send a first measurement report or a second measurement report to a first network device via a communication interface 2020.

[0353] In some embodiments, at least one processor 2010 may also be used to establish a second RRC connection with the second network device. This second Radio Resource Control connection is used for the second terminal to access the second network device.

[0354] Figure 12 This is a schematic structural diagram of a communication device provided in an embodiment of this application.

[0355] The communication device 3000 includes at least one processor 3010 and a communication interface 3020. The communication interface 3020 is used for information exchange between the communication device and other communication devices. When program instructions are executed in the at least one processor, the communication device performs the communication method described above. A first network device may include the communication device 3000.

[0356] In some embodiments, at least one processor 3010 may be configured to determine that a first terminal meets the handover conditions and that there is no session belonging to the first terminal between the first terminal and the first network device. The first terminal is a relay device for the second terminal to access the first network device, and a first radio resource control connection exists between the first terminal and the first network device.

[0357] In some embodiments, at least one processor 3010 may also be used to send radio resource control release information to a first terminal via a communication interface 3020. The radio resource control release information is used to indicate the release of the first radio resource control connection between the first terminal and the first network device.

[0358] In some embodiments, at least one processor 3010 may also be configured to receive a measurement report from a first terminal via a communication interface 3020. The measurement report includes information indicating the signal quality measured by the first terminal.

[0359] In some embodiments, at least one processor 3010 may also be used to determine, based on a received measurement report from the first terminal, that the first terminal meets the switching conditions.

[0360] In some embodiments, at least one processor 3010 may also be used to release the first radio resource control connection between the first terminal and the first network device.

[0361] In some embodiments, at least one processor 3010 may be used to determine whether there is a session belonging to the first terminal between the first terminal and the first network device, wherein the first terminal is a relay device for the second terminal to access the first network device.

[0362] In some embodiments, at least one processor 3010 may also be used to send a first radio resource control reconfiguration message to the first terminal when there is no session belonging to the first terminal, using the communication interface 3020.

[0363] In some embodiments, at least one processor 3010 may also be used to send a second radio resource control reconfiguration message to the first terminal when a session belonging to the first terminal exists, using the communication interface 3020.

[0364] In some embodiments, at least one processor 3010 may also be used to receive a first measurement report or a second measurement report from a first terminal via a communication interface 3020.

[0365] This application also provides a communication system, including the first terminal, second terminal, and first network device described above. In some embodiments, the communication system may further include a second network device.

[0366] This application also provides a computer program storage medium, characterized in that the computer program storage medium has program instructions, which, when executed, cause the method described above to be executed.

[0367] This application also provides a chip system, characterized in that the chip system includes at least one processor, and when program instructions are executed in the at least one processor, the method described above is executed.

[0368] It should be understood that the processor in the embodiments of this application can be a central processing unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0369] It should also be understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDR SDRAM), enhanced synchronous DRAM (ESDRAM), synchronous linked DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0370] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0371] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0372] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0373] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0374] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented 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 this application.

[0375] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0376] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0377] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0378] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0379] 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.

[0380] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, The method includes: When data between the second terminal and the first network device is relayed through the first terminal, and when there is no session between the first terminal and the first network device belonging to the first terminal, a first radio resource control reconfiguration message is received from the first network device. The first radio resource control reconfiguration message includes information for indicating at least one unmeasurable cell and at least one measurable cell covered by the first network device. The first terminal is a relay device for the second terminal to access the first network device, and the at least one unmeasurable cell is a cell covered by a network device other than the first network device. Signal measurement is performed based on the first radio resource control reconfiguration message; Send a first measurement report to the first network device, the first measurement report being determined based on the first radio resource control reconfiguration message; The first terminal receives a handover instruction information from the first network device, the handover instruction information being used to instruct the first terminal to hand over from its current serving cell to a first cell covered by the first network device; Based on the first cell, data is relayed between the second terminal and the first network device.

2. The method according to claim 1, characterized in that, The method further includes: When a session belonging to the first terminal exists, a second radio resource control reconfiguration message is received from the first network device. The second radio resource control reconfiguration message includes information for indicating cells covered by the first network device and / or other cells, wherein the other cells are cells outside the cells covered by the first network device. Signal measurements are performed based on the second radio resource control reconfiguration message.

3. The method according to claim 2, characterized in that, The second radio resource control reconfiguration message includes any one or more of the following: at least one measurement event, a whitelist of measurable cells, or a blacklist of unmeasurable cells, wherein the whitelist of measurable cells includes at least one measurable cell within or outside the coverage area of ​​the first network device, and the blacklist of unmeasurable cells includes at least one unmeasurable cell.

4. The method according to any one of claims 1 to 3, characterized in that, The method further includes: Before receiving the second radio resource control reconfiguration message or the first radio resource control reconfiguration message from the first network device, a second measurement report is sent to the first network device. The second measurement report includes information for indicating the signal quality measured by the first terminal.

5. A communication method, characterized in that, The method includes: When data between the second terminal and the first network device is relayed through the first terminal, it is determined whether there is a session belonging to the first terminal between the first terminal and the first network device. The first terminal is a relay device for the second terminal to access the first network device. When there is no session belonging to the first terminal, a first radio resource control reconfiguration message is sent to the first terminal. The first radio resource control reconfiguration message includes information for indicating at least one unmeasurable cell and at least one measurable cell covered by the first network device. The at least one unmeasurable cell is a cell covered by a network device other than the first network device. Receive a first measurement report from the first terminal, the first measurement report being determined based on the first radio resource control reconfiguration message; Based on the first measurement report, a handover instruction information is sent to the first terminal, the handover instruction information being used to instruct the first terminal to hand over from the current serving cell to the first cell covered by the first network device; Based on the first cell, data is transmitted between the first terminal and the second terminal.

6. The method according to claim 5, characterized in that, The method further includes: When a session belonging to the first terminal exists, a second radio resource control reconfiguration message is sent to the first terminal. The second radio resource control reconfiguration message includes information indicating cells and / or other cells covered by the first network device, wherein the other cells are cells outside the cells covered by the first network device.

7. The method according to claim 6, characterized in that, The second radio resource control reconfiguration message includes any one or more of the following: at least one measurement event, a whitelist of measurable cells, or a blacklist of unmeasurable cells, wherein the whitelist of measurable cells includes at least one measurable cell within or outside the coverage area of ​​the first network device, and the blacklist of unmeasurable cells includes at least one unmeasurable cell.

8. The method according to any one of claims 5 to 7, characterized in that, Before determining that a session belonging to the first terminal exists between the first terminal and the first network device, the method further includes: Receive a second measurement report from the first terminal, the second measurement report including information for indicating the signal quality measured by the first terminal; According to the second measurement report, it is determined that the first terminal meets the handover conditions.

9. A communication device, characterized in that, Includes a module for performing the method as described in any one of claims 1 to 4.

10. A communication device, characterized in that, Includes a module for performing the method as described in any one of claims 5 to 8.

11. A communication device, characterized in that, The communication device includes: at least one processor and a communication interface, the communication interface being used for the terminal to interact with other communication devices, and when program instructions are executed in the at least one processor, causing the communication device to perform the method as described in any one of claims 1 to 4.

12. A communication device, characterized in that, The communication device includes: at least one processor and a communication interface, the communication interface being used for the terminal to interact with other communication devices, and when program instructions are executed in the at least one processor, causing the communication device to perform the method as described in any one of claims 5 to 8.

13. A computer program product, characterized in that, Includes program instructions, when which, when executed, the method as described in any one of claims 1 to 8, is performed.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program instructions for execution by the device, wherein when the program instructions are executed, the method as described in any one of claims 1 to 8 is performed.

15. A chip, characterized in that, The chip includes at least one processor, which, when program instructions are executed in the at least one processor, causes the method as described in any one of claims 1 to 8 to be performed.

16. A communication system comprising the communication device of claim 9 or 11, the communication device of claim 10 or 12, and the second terminal.

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