Communication method and related device

Abstract

The present application provides a communication method and a related apparatus, in which a first access network device receives a first message sent by a second access network device, determines first configuration information based on a first candidate information list and / or a second candidate information list included in the first message, and sends the first configuration information to the second access network device, where the first configuration information is for a terminal device to communicate with the first access network device through a first target relay terminal, or the first configuration information is for a terminal device to communicate with the first access network device in a first target cell. In this way, a better switching link can be selected for the terminal device, thereby improving the success rate of link switching of the terminal device across different access network devices.

Description

[Technical Field]

[0001] TECHNICAL FIELD This application relates to the field of communications technology, and more particularly to communications methods and related devices. [Background technology]

[0002] Currently, a terminal device can be handed over from an indirect link to a direct link. For example, the terminal device is handed over from communicating with an access network device through a relay terminal to communicating directly with the access network device. Of course, the terminal device can alternatively be handed over from a direct link to an indirect link. For example, the terminal device is handed over from communicating directly with the access network device to communicating with the access network device through a relay terminal. However, regardless of whether the terminal device is handed over from an indirect link to a direct link or from a direct link to an indirect link, it can be understood that the terminal device is handed over in the same access network device. In other words, the problem of how to hand over a terminal device in a different access network device still needs to be solved. Summary of the Invention

[0003] The present application provides a communication method and related apparatus for improving the success rate of link switching for end devices in different access network devices.

[0004] According to a first aspect, a method includes: a step of a first access network device receiving a first message transmitted by a second access network device, wherein the first message includes a first candidate information list and / or a second candidate information list, the first candidate information list including information about one or more candidate relay terminals, the one or more candidate relay terminals being located in one or more cells served by the first access network device, and the second candidate information list including information about one or more candidate cells served by the first access network device; the first access network device receiving the first candidate information list and / or a second candidate information list, or a step of determining first configuration information based on the second candidate information list, where the first configuration information is used by the terminal device to communicate with the first access network device through a first target relay terminal, the first target relay terminal being one of one or more candidate relay terminals; or the first configuration information is used by the terminal device to communicate with the first access network device in a first target cell, the first target cell being a cell in one or more candidate cells; and a step of the first access network device transmitting the first configuration information to the second access network device. It may be understood that the first access network device may receive the first message transmitted by the second access network device to determine the first configuration information based on the first candidate information list and / or the second candidate information list included in the first message. The first configuration information is used by the terminal device to communicate with the first access network device through the first target relay terminal. In this way, the first access network device can be involved in selecting a target relay terminal in the target cell by using the first candidate information list, in other words, the first access network device can determine that the link to which the terminal device needs to be handed over is an indirect link.Alternatively, the first configuration information is used by the terminal device to communicate with the first access network device in the first target cell, and the first access network device can participate in selecting the target cell by using the second candidate information list; in other words, the first access network device can determine that the link to which the terminal device needs to be handed over is a direct link. In this way, a better switching link can be selected for the terminal device, thereby improving the success rate of link switching of the terminal device in a different access network device. In addition, the first configuration information is sent to the second access network device, so that the terminal device can obtain the first configuration information from the second access network device and further communicate with the second access network device.

[0005] In this application, the information about the candidate relay terminal may include at least one of: an identifier of the candidate relay terminal, a signal quality on the link between the terminal device and the candidate relay terminal, or an identifier of the serving cell of the candidate relay terminal.

[0006] Optionally, the identifier of the candidate relay terminal may include, for example, one or more of: a system architecture evolution (SAE, temporary mobile station identifier, S-TMSI), a globally unique temporary identity (GUTI), a subscription permanent identifier (SUPI), an access network temporary identifier (radio network temporary identifier, RNTI), a layer-2 identifier (layer-2 ID), and a local identifier assigned to the candidate relay terminal by a network device.

[0007] The signal quality on the link between the terminal device and the candidate relay terminal may include at least one of: reference signal received power (RSRP), reference signal received quality (RSRQ), or signal to interference plus noise ratio (SINR). In a possible implementation, the link between the terminal device and the candidate relay terminal is a sidelink (SL). The signal quality on the sidelink between the terminal device and the candidate relay terminal may also be referred to as the signal quality on the PC5 interface between the terminal device and the candidate relay terminal.

[0008] It should be noted that SL is defined for direct communication between terminal devices, in other words, the link that terminal devices use to communicate directly with each other without forwarding by a base station. The interface between terminal devices can be referred to as a PC5 interface.

[0009] Optionally, the identifier of the serving cell of the candidate relay terminal may include, for example, at least one of: a new radio cell identity (NR cell identity, NCI) or an NR cell global identifier (NR cell global identifier, NCGI).

[0010] Optionally, the information about the candidate relay terminals in the first candidate information list may be, for example, information about all candidate relay terminals reported by the terminal device, or the information about the candidate relay terminals in the first candidate information list may be, for example, information about some candidate relay terminals among the candidate relay terminals reported by the terminal device.

[0011] It should be noted that in this application, the information about the candidate relay terminal in the first candidate information list may be identical or partially identical to the information about the corresponding candidate relay terminal reported by the terminal device.

[0012] The plurality of candidate relay terminals located in one or more cells served by the first access network device may be understood as one of: the plurality of candidate relay terminals located in one cell served by the first access network device, different candidate relay terminals among the plurality of candidate relay terminals located in different cells served by the first access network device, and some of the plurality of candidate relay terminals located in one cell served by the first access network device and some others of the plurality of candidate relay terminals located in another cell served by the first access network device. It should be understood that the protocol may restrict that the candidate relay terminals in the first candidate information list must be located in one cell, or may not restrict that the candidate relay terminals in the first candidate information list must be located in one cell. In this case, different candidate relay terminals among the plurality of candidate relay terminals are located in different cells served by the first access network device, or some of the plurality of candidate relay terminals are located in one cell served by the first access network device and some others of the plurality of candidate relay terminals are located in another cell served by the first access network device.

[0013] In the present application, the information about the candidate cell may include at least one of: an identifier of the candidate cell, or a signal quality between the terminal device and the first access network device in the candidate cell. The signal quality between the terminal device and the first access network device in the candidate cell may include at least one of: a reference signal received power, a reference signal received quality, or a signal-to-interference-plus-noise ratio. It should be understood that the signal quality between the terminal device and the first access network device in the candidate cell may also be referred to as a signal quality between the terminal device and the first access network device on the Uu interface in the candidate cell. The identifier of the candidate cell may include, for example, at least one of: an NCI or an NCGI.

[0014] Optionally, the information about the candidate cells in the second candidate information list may be, for example, information about all candidate cells reported by the terminal device, or the information about the candidate cells in the second candidate information list may be, for example, information about some candidate cells among the candidate cells reported by the terminal device.

[0015] It should be noted that in this application, the information about the candidate cells in the second candidate information list may be identical or partially identical to the information about the corresponding candidate cells reported by the terminal device.

[0016] Optionally, referring to the first aspect, before the first access network device determines the first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: the first access network device determines a first target relay terminal based on the first candidate information list, where the first target relay terminal is one of a plurality of candidate relay terminals. This means that the first access network device can participate in selecting a target relay terminal in the target cell by using the first candidate information list; in other words, the first access network device can determine that the link to which the terminal device needs to be handed over is an indirect link. In this way, a better switching link can be selected for the terminal device, and as a result, the success rate of link switching of the terminal device in different access network devices can be improved.

[0017] Optionally, when the first configuration information is used by the terminal device to communicate with the first access network device through the first target relay terminal, the first configuration information may include, for example, an end-to-end bearer configuration between the terminal device and the first access network device, a radio link control (RLC) bearer configuration between the terminal device and the first target relay terminal, and a mapping relationship between the end-to-end bearer and the RLC bearer.

[0018] In this application, an RLC bearer is a protocol entity and structure under the RLC layer, a lower layer part of a radio bearer (RB), and includes RLC layer entities and a set of resources such as logical channels. RLC bearers can be classified as RLC bearers between terminal devices and access network devices, and RLC bearers between terminal devices.

[0019] In this application, an end-to-end bearer is a protocol entity and structure above the RLC layer, which is the upper layer of the RB and includes a set of resources such as packet data convergence protocol (PDCP) layer entities.

[0020] Optionally, when the first configuration information is used by the terminal device to communicate with the first access network device in the first target cell, the first configuration information may include, for example, at least one of: a radio bearer configuration between the terminal device and the first access network device, an RLC bearer configuration between the terminal device and the first access network device, or a configuration required by the terminal device to access the target access network device through random access.

[0021] Optionally, referring to the first aspect, before the first access network device determines the first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: the first access network device determining a first target cell based on the second candidate information list. This means that the first access network device can further participate in selecting a target cell by using the second candidate information list; in other words, the first access network device can determine that the link to which the terminal device needs to be handed over is a direct link. In this way, a better switching link can be selected for the terminal device, and as a result, the success rate of link switching of the terminal device in different access network devices can be increased.

[0022] Optionally, referring to the first aspect, the first message further includes a first identifier. The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device. The first message may, for example, be a handover request message. The first identifier may, for example, be a target cell global ID in the handover request message. This is equivalent to reusing the handover request message. This is compatible with existing protocols, may reduce impact on existing protocols, and may improve backward compatibility of the protocol.

[0023] Optionally, the identifiers of the cells recommended by the second access network device to the first access network device may include at least one of: identifiers of cells in which one or more of the candidate relay terminals reported by the terminal device are located, or identifiers of candidate cells reported by the terminal device.

[0024] For example, when the first message includes a first candidate information list, the first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device. Optionally, the identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located may be included in the first candidate information list. The identifier of the cell recommended by the second access network device to the first access network device may be the identifier of a cell in which one or more of the candidate relay terminals reported by the terminal device are located. In this case, in a possible implementation, the identifier of a cell in which one or more of the candidate relay terminals reported by the terminal device are located may be included in the first candidate information list.

[0025] In another example, when the first message includes the second candidate information list, the first identifier includes at least one of: an identifier predefined in the protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device. Optionally, the identifier of any candidate cell reported by the terminal device may be included in the second candidate information list. The identifier of the cell recommended by the second access network device to the first access network device may be the identifier of the candidate cell reported by the terminal device. In this case, in a possible implementation, information about the candidate cell reported by the terminal device may be included in the second candidate information list.

[0026] In another example, when the first message includes a first candidate information list and a second candidate information list, the first identifier includes at least one of: an identifier predefined in a protocol, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device. Optionally, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located may be included in the first candidate information list, and an identifier of any candidate cell reported by the terminal device may be included in the second candidate information list. An identifier of a cell recommended by the second access network device to the first access network device may include an identifier of a cell in which one or more of the candidate relay terminals reported by the terminal device are located and an identifier of the candidate cell reported by the terminal device. In this case, in a possible implementation, information about cells in which one or more of the candidate relay terminals reported by the terminal device are located may include the first candidate information list, and information about the candidate cell reported by the terminal device may be included in the second candidate information list.

[0027] Optionally, with reference to the first aspect, the first access network device ignores the cell indicated by the first identifier when the first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, or a random value determined by the second access network device. When the first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, or an identifier of any candidate cell reported by the terminal device, the first access network device may ignore the cell indicated by the first identifier, such that it may be known that the first access network device does not refer to the cell indicated by the first identifier when involved in selecting a target relay terminal in the target cell or when involved in selecting a target cell.

[0028] Optionally, referring to the first aspect, when the first access network device acquires the first candidate information list and / or the second candidate information list, the first access network device ignores the cell indicated by the first identifier. It may be seen that when the first access network device acquires the first candidate information list and / or the second candidate information list, regardless of what the first identifier indicates, the first access network device directly ignores the cell indicated by the first identifier, so that the first access network device does not refer to the cell indicated by the first identifier when participating in the selection of a target relay terminal in the target cell or when participating in the selection of the target cell.

[0029] Optionally, referring to the first aspect, when the first identifier is an identifier of a cell recommended to the first access network device by the second access network device, determining the first target relay terminal based on the first candidate information list by the first access network device includes: the first access network device determining the first target relay terminal based on the first candidate information list and the cell indicated by the first identifier. It may be seen that when the first identifier is an identifier of a cell recommended to the first access network device by the second access network device, the first access network device may determine the first target relay terminal based on the first candidate information list and the cell indicated by the first identifier. This indicates that the first access network device may further refer to the cell indicated by the first identifier when participating in selection of a target relay terminal in the target cell.

[0030] Optionally, with reference to the first aspect, when the first identifier is an identifier of a cell recommended to the first access network device by the second access network device, determining the first target cell based on the second candidate information list by the first access network device includes: the first access network device determining the first target cell based on the second candidate information list and the cell indicated by the first identifier. It may be seen that when the first identifier is an identifier of a cell recommended to the first access network device by the second access network device, the first access network device may determine the first target cell based on the second candidate information list and the cell indicated by the first identifier. This indicates that the first access network device may further refer to the cell indicated by the first identifier when involved in cell selection.

[0031] Optionally, referring to the first aspect, the first message further includes first indication information, where the first indication information indicates that the first identifier is an identifier predefined in a protocol; or the first indication information indicates that the first identifier is an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is an identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is an identifier of a cell recommended by the second access network device to the first access network device; or the first indication information indicates that the first identifier is a random value determined by the second access network device. It may be seen that when the first identifier includes at least one of: an identifier predefined in the protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device, the first access network device can recognize the particular type of the first identifier by using the first indication information.

[0032] According to a second aspect, a method includes: a step of receiving, by a second access network device, information about one or more candidate relay terminals reported by a terminal device and / or information about one or more candidate cells reported by the terminal device; a step of determining, by the second access network device, a first candidate information list and / or a second candidate information list based on the information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device, wherein the first candidate information list includes information about one or more candidate relay terminals, the one or more candidate relay terminals being located in one or more cells served by the first access network device, and the second candidate information list includes information about one or more candidate cells served by the first access network device. A communication method is provided, comprising: a step of the second access network device sending a first message to the first access network device, wherein the first message includes a first candidate information list and / or a second candidate information list; a step of the second access network device receiving first configuration information sent by the first access network device, wherein the first configuration information is used by the terminal device to communicate with the first access network device through a first target relay terminal, wherein the first target relay terminal is one of a plurality of candidate relay terminals; or a step of the first configuration information is used by the terminal device to communicate with the first access network device in a first target cell, wherein the first target cell is a cell in one or more candidate cells; and a step of the second access network device sending the first configuration information to the terminal device.

[0033] The second access network device determining the first candidate information list based on information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device may be understood as the second access network device determining the first candidate information list based on information about one or more candidate relay terminals reported by the terminal device, or as the second access network device determining the first candidate information list based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device. Similarly, the second access network device determining the second candidate information list based on information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device may be understood as the second access network device determining the second candidate information list based on information about one or more candidate cells reported by the terminal device, or the second access network device determining the second candidate information list based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device.

[0034] Optionally, referring to the second aspect, the first message further includes a first identifier, which includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device.

[0035] Optionally, referring to the second aspect, the first message further includes first indication information, wherein the first indication information indicates that the first identifier is an identifier predefined in a protocol; or the first indication information indicates that the first identifier is an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is an identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is an identifier of a cell recommended by the second access network device to the first access network device; or the first indication information indicates that the first identifier is a random value determined by the second access network device.

[0036] According to a third aspect, a method includes the steps of: a terminal device reporting information about one or more candidate relay terminals and information about one or more candidate cells to a second access network device; a terminal device receiving first configuration information transmitted by the second access network device; and a terminal device communicating with the first access network device through a first target relay terminal based on the first configuration information, or a terminal device communicating with the first access network device in a first target cell based on the first configuration information, wherein the first configuration information is determined by the first access network device based on a first message transmitted by the second access network device, the first message including a first candidate information list and / or a second candidate information list, the first candidate information list being transmitted to the terminal device. a first candidate information list is determined by a second access network device based on information about one or more candidate relay terminals reported by the terminal device, the second candidate information list being determined by the second access network device based on information about one or more candidate cells reported by the terminal device; the first candidate information list includes information about one or more candidate relay terminals, the one or more candidate relay terminals being located in one or more cells served by the first access network device, and the first target relay terminal being one of the one or more candidate relay terminals; and the second candidate information list includes information about one or more candidate cells served by the first access network device, and the first target cell is a cell in the one or more candidate cells.

[0037] Optionally, referring to the third aspect, the first message further includes a first identifier, which includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device.

[0038] Optionally, referring to the third aspect, the first message further includes first indication information, wherein the first indication information indicates that the first identifier is an identifier predefined in a protocol; or the first indication information indicates that the first identifier is an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is an identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is an identifier of a cell recommended by the second access network device to the first access network device; or the first indication information indicates that the first identifier is a random value determined by the second access network device.

[0039] According to a fourth aspect, the method includes: a step of a second access network device receiving information about one or more candidate relay terminals reported by a terminal device and / or information about one or more candidate cells reported by the terminal device; a step of the second access network device determining a first candidate information list and / or a second candidate information list based on the information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device, wherein the first candidate information list includes information about one or more candidate relay terminals, the one or more candidate relay terminals being located in one or more cells served by the first access network device, and the second candidate information list includes information about one or more candidate cells served by the first access network device; a step of the second access network device sending the first message to a second access network device; A communication method is provided, comprising: a step of transmitting a first message to a first access network device, wherein the first message includes a first candidate information list and / or a second candidate information list; a step of the first access network device determining first configuration information based on the first candidate information list and / or the second candidate information list, wherein the first configuration information is used by the terminal device to communicate with the first access network device through a first target relay terminal, the first target relay terminal being one of one or more candidate relay terminals; or a step of the first configuration information is used by the terminal device to communicate with the first access network device in a first target cell, the first target cell being a cell in one or more candidate cells; a step of the first access network device transmitting the first configuration information to a second access network device; and a step of the second access network device transmitting the first configuration information to the terminal device.

[0040] Optionally, referring to a fourth aspect, before the first access network device determines the first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: the first access network device determining a first target relay terminal based on the first candidate information list, wherein a serving cell of the first target relay terminal is one of the one or more cells.

[0041] Optionally, referring to the fourth aspect, before the first access network device determines the first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: the first access network device determining a first target cell based on the second candidate information list.

[0042] Optionally, referring to the fourth aspect, the first message further includes a first identifier, which includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device.

[0043] Optionally, referring to a fourth aspect, when the first identifier is an identifier of a cell recommended to the first access network device by the second access network device, determining by the first access network device the first target relay terminal based on the first candidate information list includes: the first access network device determining the first target relay terminal based on the first candidate information list and the cell indicated by the first identifier.

[0044] Optionally, referring to a fourth aspect, if the first identifier is an identifier of a cell recommended to the first access network device by the second access network device, determining the first target cell based on the second candidate information list by the first access network device includes: the first access network device determining the first target cell based on the second candidate information list and a cell indicated by the first identifier.

[0045] According to a fifth aspect, there is provided a communications device, the communications device comprising a module configured to perform a method according to any one of the first, second, third or fourth aspects.

[0046] According to a sixth aspect, there is provided a communications device comprising a processor, the processor coupled to a memory, the memory storing a computer program, the processor configured to invoke the computer program in the memory, such that the communications device performs a method according to any one of the first, second, third or fourth aspects.

[0047] In a possible design, the communications apparatus may be a chip or a device including a chip implementing a method according to the first, second, third or fourth aspect.

[0048] According to a seventh aspect, there is provided a communication device comprising a processor and an interface circuit, the interface circuit being configured to: receive signals from another communication device other than the communication device, transmit signals to the processor, or transmit signals from the processor to another communication device other than the communication device, and the processor being configured to implement a method according to the first, second, third or fourth aspect by using logic circuits or by executing code instructions.

[0049] According to an eighth aspect, there is provided a computer-readable storage medium, the storage medium storing a computer program or instructions which, when executed by a computer, implements a method according to any one of the first, second, third or fourth aspects.

[0050] According to a ninth aspect, there is provided a computer program product which, when read and executed by a computer, enables the computer to carry out a method according to any one of the first, second, third or fourth aspects.

[0051] According to a tenth aspect, there is provided a communication system, the communication system including one or more of: a first access network device performing a method according to any possible implementation of the first aspect; and a second access network device performing a method according to any possible implementation of the second aspect. Optionally, the communication system may further include a terminal device performing a method according to any possible implementation of the third aspect. [Brief explanation of the drawings]

[0052] The accompanying drawings used to explain the embodiments are briefly described below.

[0053] [Figure 1] 1 illustrates a basic architecture of a communication system according to an embodiment of the present application. [Figure 2] 1 is a diagram of a hardware structure of a communication device applicable to an embodiment of the present application; [Figure 3A] 1 is a schematic flowchart of a communication method according to an embodiment of the present application; [Figure 3B] 4 is a schematic flowchart of another communication method according to an embodiment of the present application; [Figure 3C] 4 is a schematic flowchart of another communication method according to an embodiment of the present application; [Figure 3D] 4 is a schematic flowchart of another communication method according to an embodiment of the present application; [Figure 3E] 4 is a schematic flowchart of another communication method according to an embodiment of the present application; [Figure 4] 1 is a diagram of the structure of a communication device according to an embodiment of the present application; [Figure 5] 1 is a simplified diagram of the structure of a terminal device according to an embodiment of the present application; [Figure 6] 1 is a simplified diagram of the structure of an access network device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0054] The following describes the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. In the embodiments of the present application, the terms "system" and "network" can be used interchangeably. Unless otherwise specified, " / " represents an "or" relationship between associated objects. For example, A / B can represent A or B. The term "and / or" in this application is merely a relational relationship for describing associated objects and represents that three relationships may exist. For example, A and / or B can represent three cases: only A exists, both A and B exist, and only B exists, and A and B can each be singular or plural. In addition, in the description of this application, "plurality" means two or more than two unless otherwise specified. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of a single item or multiple items. For example, at least one of a, b, or c may represent a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c may be singular or plural. In addition, in order to clearly describe the technical solutions in the embodiments of the present application, terms such as "first" and "second" are used in the embodiments of the present application to distinguish between identical or similar items that basically have the same network elements or effects. Those skilled in the art will understand that terms such as "first" and "second" do not limit the quantity or execution order, and terms such as "first" and "second" do not indicate clear distinctions.

[0055] References to "an embodiment," "some embodiments," or the like, described in the context of embodiments herein indicate that one or more embodiments herein include the particular feature, structure, or characteristic described with reference to the embodiment. Thus, the appearance of phrases such as "in an embodiment," "in some embodiments," "in some other embodiments," and "in other embodiments" in various places throughout this specification are not necessarily referring to the same embodiment. Instead, such phrases mean "one or more, but not all, of the embodiments," unless specifically emphasized otherwise. The terms "comprising," "including," "having," and their derivatives all mean "including but not limited to," unless specifically emphasized otherwise.

[0056] The objectives, technical solutions and beneficial effects of the present application are further described in detail in the following specific implementations. It should be understood that the following description is only a specific implementation of the present application and is not intended to limit the protection scope of the present application. Any modifications, equivalent replacements or improvements made based on the technical solutions of the present application shall fall within the protection scope of the present application.

[0057] In the embodiments of the present application, unless otherwise specified or there is a logical contradiction, the descriptions of the terms and / or in different embodiments are consistent and can be cross-referenced, and the technical features in different embodiments can be combined into a new embodiment based on their internal logical relationships.

[0058] The technical solutions in the embodiments of the present application are based on the Long Term Evolution (LTE) architecture, the fifth generation mobile communication technology (5G). thIt should be understood that the technical solutions in the embodiments of the present application are applicable to future communication systems, such as 5G (Next Generation Mobile Networks), wireless local area networks (WLAN) systems, V2X communication systems, and the like. The technical solutions in the embodiments of the present application are also applicable to other future communication systems, such as 6G communication systems. In future communication systems, the same functions may be maintained, but the names may be changed.

[0059] The following describes the basic architecture of a communication system provided in an embodiment of the present application. Figure 1 shows the basic architecture of a communication system according to an embodiment of the present application. It should be noted that in this application, a direct link or path is a link or path through which a terminal device communicates with an access network device, and an indirect link is a link or path through which a terminal device communicates with an access network device via an intermediate terminal.

[0060] 1-1, it can be seen that this embodiment of the present application is applicable to switching from a direct link, in which a terminal device 30 communicates with a source access network device 10, to an indirect link, in which the terminal device 30 communicates with a target access network device 20 through a target relay terminal (relay user equipment, Relay UE) 40. In a cell A of the source access network device 10, the terminal device 30 may communicate with the source access network device 10 on the direct link. When the terminal device 30 performs communication through the relay terminal 40, the terminal device 30 may also be referred to as a remote terminal (remote UE) or a remote terminal device. When the link quality of the direct link between the terminal device 30 and the source access network device 10 is less than or equal to a first predetermined threshold, the terminal device 30 needs to be handed over from the direct link, in which the terminal device 30 communicates with the source access network device 10, to an indirect link, in which the terminal device 30 communicates with the target access network device 20 through the target relay terminal 40. The first predetermined threshold may be predefined in a protocol, configured for the terminal device by the source access network device, or may be a fixed value. The present invention is not limited thereto. For example, cells served by the target access network device 20 may include one or more candidate cells, such as candidate cell C and candidate cell D. In the present application, a candidate cell may be used as a candidate for the target cell, i.e., a target cell may be determined from one or more candidate cells. For example, in 1-1 of FIG. 1, target cell B is actually determined from one or more candidate cells. Furthermore, each candidate cell includes one or more candidate relay terminals. For example, candidate cell C or candidate cell D may include one or more candidate relay terminals (not shown in 1-1 of FIG. 1). In the present application, a candidate relay terminal may be used as a candidate for the target relay terminal, i.e., a target relay terminal may be determined from one or more candidate relay terminals.It should be noted that after the target cell B is determined, the target relay terminal 40 in the target cell B needs to be further determined.

[0061] 1-2, it can be seen that this embodiment of the present application is also applicable to a scenario in which an indirect link, in which a terminal device 30 communicates with a source access network device 10 through a relay terminal 50, is handed over to a direct link, in which the terminal device 30 communicates with a target access network device 20. Specifically, in a cell A of the source access network device 10, the terminal device 30 may communicate with the source access network device 10 on the indirect link through the relay terminal 50. When the link quality of the indirect link, in which the terminal device 30 communicates with the source access network device 10 through the relay terminal 50, is less than or equal to a second predetermined threshold, the terminal device 30 needs to be handed over from the indirect link, in which the terminal device 30 communicates with the source access network device 10 through the relay terminal 50, to a direct link, in which the terminal device 30 communicates with the target access network device 20 in a target cell B. The second predetermined threshold may be predefined in a protocol, or may be configured for the terminal device by the source access network device, or may be a fixed value. The present invention is not limited thereto. For example, the cells served by the target access network device 20 may include one or more candidate cells, such as, for example, candidate cell C and candidate cell D. The target cell B is actually determined from one or more candidate cells.

[0062] 1-3, it can be seen that this embodiment of the present application is further applicable to a scenario in which a direct link through which a terminal device 30 communicates with a source access network device 10 is switched to a direct link through which the terminal device 30 communicates with a target access network device 20. Specifically, in a cell A of the source access network device 10, the terminal device 30 may communicate with the source access network device 10 on the direct link. When the link quality of the direct link between the terminal device 30 and the source access network device 10 is less than or equal to a first predetermined threshold, the terminal device 30 needs to be handed over from the direct link through which the terminal device 30 communicates with the source access network device 10 to the direct link through which the terminal device 30 communicates with the target access network device 20 in a target cell B. For the manner of determining the target cell B, please refer to 1-2 of FIG. 1.

[0063] 1-4, it can be seen that the present embodiment of the present application is further applicable to a scenario in which an indirect link in which a terminal device 30 communicates with a source access network device 10 through a relay terminal 60 is switched to an indirect link in which the terminal device 30 communicates with a target access network device 20 through a target relay terminal 70. Specifically, in a cell A of the source access network device 10, the terminal device 30 may communicate with the source access network device 10 on the indirect link through the relay terminal 60. When the link quality of the indirect link in which the terminal device 30 communicates with the source access network device 10 through the relay terminal 60 is less than or equal to a second predetermined threshold, the terminal device 30 needs to be handed over from the indirect link in which the terminal device 30 communicates with the source access network device 10 through the relay terminal 60 to the indirect link in which the terminal device 30 communicates with the target access network device 20 through the target relay terminal 70.

[0064] It should be noted that in the present application, a relay terminal (e.g., target relay terminal 40, target relay terminal 50, candidate relay terminal, relay terminal 50, or relay terminal 60) may perform sidelink communication with the terminal device 30. SL is defined for direct communication between terminal devices, in other words, it is a link used by terminal devices to communicate directly with each other without forwarding by a base station. An interface between terminal devices is used for direct communication between terminal devices, and the interface between terminal devices may be referred to as a PC5 interface. It may be understood that FIG. 1 is merely a diagram and does not constitute a limitation on the application scenario of the technical solution provided in the present application. The source access network device 10 or the target access network device 20 in FIG. 1 is a network-side entity configured to transmit signals, receive signals, or transmit and receive signals. The source access network device 10 or the target access network device 20 may be a device deployed in a radio access network (RAN) and providing wireless communication capabilities to terminal devices, such as a transmission reception point (TRP), a base station, or a control node in various forms, such as a network controller, a radio controller, or a radio controller in a cloud radio access network (CRAN) scenario.Specifically, the source access network device 10 or the target access network device 20 may be various forms of macro base stations, micro base stations (also referred to as small stations), relay stations, access points (APs), radio network controllers (RNCs), Node Bs (NBs), base station controllers (BSCs), base transceiver stations (BTSs), home base stations (e.g., home evolved Node Bs or home Node Bs (HNBs)), base band units (BBUs), transmitting and receiving points (TRPs), transmitting points (TPs), mobile switching centers, satellites, unmanned aerial vehicles, or the like, or may be antenna panels of base stations. A control node may be connected to multiple base stations and configure resources for multiple terminals covered by the multiple base stations. In systems using different radio access technologies, the names of devices with base station functionality may differ. For example, the access network device may be a gNB in ​​5G, a network side device in a post-5G network, an access network device in a future evolved public land mobile network (PLMN), or a device having base station functionality in device-to-device (D2D) communication, machine-to-machine (M2M) communication, or Internet of Vehicles communication. The specific name of the access network device is not limited in this application. In addition, the source access network device 10 or the target access network device 20 may further include a distributed unit (DU) and a central unit (CU).

[0065] 1 , a target relay terminal (e.g., target relay terminal 40 or target relay terminal 50), a candidate relay terminal, a relay terminal (e.g., relay terminal 50 or relay terminal 60), or a terminal device 30 is a user-side entity configured to receive a signal, transmit a signal, or receive and transmit a signal. The target relay terminal, candidate relay terminal, relay terminal, or terminal device 30 is configured to provide one or more of a voice service and a data connectivity service to a user. The target relay terminal, candidate relay terminal, relay terminal, or terminal device 30 may be a device including a radio transceiver function capable of providing a communication service to a user in cooperation with an access network device. Specifically, the target relay terminal, candidate relay terminal, relay terminal, or terminal device 30 may be a user equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote station, a remote terminal, a mobile device, a terminal, a wireless communication device, a user agent, or a user device.The relay terminal or terminal device may alternatively be an unmanned aerial vehicle, an internet of things (IoT) device, a station (ST) in a WLAN, a cellular phone, a smartphone, a cordless phone, a wireless data card, a tablet computer, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA) device, a laptop computer, a machine type communication (MTC) terminal, a handheld device with wireless communication capabilities, a computing device or another processing device connected to a wireless modem, an in-vehicle device, a wearable device (also called a wearable intelligent device), a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, or the like. The target relay terminal, the candidate relay terminal, the relay terminal, or the terminal device 30 may alternatively be a device-to-device (D2D) device, for example, an electricity meter or a water meter. Alternatively, the target relay terminal, the candidate relay terminal, the relay terminal, or the terminal device 30 may be a terminal in a 5G system, or a terminal in a next-generation communication system. This is not limited to this embodiment of the present application.

[0066] Optionally, the devices in FIG. 1 (e.g., the source access network device 10, the target access network device 20, the terminal device 30, the target relay terminal (e.g., the target relay terminal 40 or the target relay terminal 50), the candidate relay terminal, and the relay terminal (e.g., the relay terminal 50 or the relay terminal 60)) may be implemented by one device, or may be implemented together by multiple devices, or may be function modules in one device. This is not specifically limited in this embodiment of the present application. It may be understood that the above functions may be network elements in a hardware device, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform).

[0067] For example, each device in Fig. 1 may be implemented by a communication device 200 in Fig. 2. Fig. 2 is a diagram of a hardware structure of a communication device applicable to an embodiment of the present application. The communication device 200 includes at least one processor 201, a communication line 202, a memory 203, and at least one communication interface 204.

[0068] The processor 201 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to control program execution in the solutions herein.

[0069] The communication lines 202 may include paths that are used to transmit information between the above components.

[0070] The communication interface 204 may be any device, such as a transceiver (e.g., an antenna), configured to communicate with another device or a communication network, which may be an Ethernet, RAN, wireless local area network (WLAN), or the like.

[0071] The memory 203 may be, but is not limited to, read-only memory (ROM) or another type of static storage device capable of storing static information and instructions, random access memory (RAM) or another type of dynamic storage device capable of storing information and instructions, electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact optical disks, laser disks, optical disks, digital versatile optical disks, Blu-ray disks, and the like), magnetic disk storage media or other magnetic storage devices, or any other medium capable of holding or storing desired program code in the form of instructions or data structures and accessible by a computer. The memory may be independent and connected to the processor through communication line 202. Alternatively, the memory may be integrated with the processor. The memory provided in the embodiments of the present application may typically be non-volatile.

[0072] The memory 203 is configured to store computer-executable instructions for executing the solutions in the present application, and the processor 201 controls the execution. The processor 201 is configured to execute the computer-executable instructions stored in the memory 203 to implement the methods provided in the following embodiments of the present application.

[0073] Optionally, the computer-executable instructions in this embodiment of the present application may also be referred to as application program code, which is not specifically limited in this embodiment of the present application.

[0074] In a possible implementation, processor 201 may include one or more CPUs, for example, CPU0 and CPU1 of FIG.

[0075] In a possible implementation, communications device 200 may include multiple processors, such as processor 201 and processor 207 of FIG. 2. Each of the processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor, where a processor may be one or more device circuits and / or processing cores configured to process data (e.g., computer program instructions).

[0076] In a possible implementation, the communication apparatus 200 may further include an output device 205 and an input device 206. The output device 205 communicates with the processor 201 and may display information in a variety of ways. For example, the output device 205 may be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device 206 communicates with the processor 201 and may receive input from a user in a variety of ways. For example, the input device 206 may be a mouse, a keyboard, a touch screen device, or a sensor device.

[0077] The communication device 200 may be a general-purpose device or a dedicated device. In a specific implementation, the communication device 200 may be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device, or a device having a structure similar to that of FIG. 2. The type of the communication device 200 is not limited to this embodiment of the present application.

[0078] It should be noted that in this application, the first access network device may be referred to as a target access network device, and the second access network device may be referred to as a source access network device, or other names may be used. This is not intended to be limiting. It should be understood that the source access network device in Figures 3A to 3E may be, for example, the source access network device 10 in Figure 1; the target access network device in Figures 3A to 3E may be, for example, the target access network device 20 in Figure 1; the terminal device in Figures 3A to 3E may be, for example, the terminal device 30 in Figure 1; the candidate relay terminal in Figures 3A to 3E may be, for example, the candidate relay terminal in Figure 1; the target relay terminal in Figures 3A to 3E may be, for example, the target relay terminal in Figure 1; and the relay terminal in Figures 3A to 3E may be, for example, the relay terminal in Figure 1.

[0079] 3A is a schematic flowchart of a communication method according to an embodiment of the present application. As shown in FIG. 3A, the method includes, but is not limited to, the following steps:

[0080] 301: A terminal device reports information about one or more candidate relay terminals and / or information about one or more candidate cells to a source access network device.

[0081] Correspondingly, the source access network device receives information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device.

[0082] Optionally, step 301 may include: when the link quality of a direct link through which the terminal device communicates with the source access network device is less than or equal to a first predetermined threshold, or the link quality of an indirect link through which the terminal device communicates with the source access network device through a relay terminal is less than or equal to a second predetermined threshold, the terminal device reports information about one or more candidate relay terminals and / or information about one or more candidate cells to the source access network device.

[0083] It should be understood that the number of candidate relay terminals reported by the terminal device to the source access network device may be one or more, and the one or more candidate relay terminals are located in one or more cells served by the target access network device.

[0084] In this application, the location of multiple candidate relay terminals in one or more cells served by the target access network device may be understood as, for example, one of the following: the multiple candidate relay terminals are located in the same cell served by the target access network device, different candidate relay terminals among the multiple candidate relay terminals are located in different cells served by the target access network device, and some of the multiple candidate relay terminals are located in one cell served by the target access network device and some others of the multiple candidate relay terminals are located in another cell served by the target access network device. For example, information about three candidate relay terminals is information about candidate relay terminal 1, information about candidate relay terminal 2, and information about candidate relay terminal 3. In a possible implementation, the three candidate relay terminals are located in one cell served by the target access network device. In another possible implementation, candidate relay terminal 1 is located in cell 1 served by the target access network device, candidate relay terminal 2 is located in cell 2 served by the target access network device, and candidate relay terminal 3 is located in cell 3 served by the target access network device. In yet another possible implementation, candidate relay terminal 1 and candidate relay terminal 2 are located in cell 1 served by the target access network device, and candidate relay terminal 3 is located in cell 2 served by the target access network device.

[0085] In this application, the information about the candidate relay terminal may include at least one of: an identifier of the candidate relay terminal, a signal quality on the link between the terminal device and the candidate relay terminal, or an identifier of the serving cell of the candidate relay terminal.

[0086] Optionally, the identifier of the candidate relay terminal may include, for example, one or more of: S-TMSI, GUTI, SUPI, RNTI, a Layer 2 identifier, a local identifier assigned to the candidate relay terminal by a network device, and the like.

[0087] The signal quality on the link between the terminal device and the candidate relay terminal may include at least one of: reference signal received power, reference signal received quality, or signal-to-interference-plus-noise ratio. In a possible implementation, the link between the terminal device and the candidate relay terminal is an SL. The signal quality on the SL between the terminal device and the candidate relay terminal may also be referred to as signal quality on the PC5 interface between the terminal device and the candidate relay terminal.

[0088] Optionally, the identifier of the serving cell of the candidate relay terminal may include, for example, at least one of: NCI or NCGI.

[0089] The number of candidate cells reported by the terminal device to the source access network device may be one or more.

[0090] In the present application, the information about the candidate cell may include at least one of: an identifier of the candidate cell, or a signal quality between the terminal device and the target access network device in the candidate cell. The signal quality between the terminal device and the target access network device in the candidate cell may include at least one of: a reference signal received power, a reference signal received quality, or a signal-to-interference-plus-noise ratio. It should be understood that the signal quality between the terminal device and the target access network device in the candidate cell may also be referred to as a signal quality between the terminal device and the target access network device on the Uu interface in the candidate cell.

[0091] The candidate cell identifier may include, for example, at least one of: NCI or NCGI.

[0092] Optionally, before step 301, the method may further include: a step in which the terminal device receives measurement configuration information sent by the source access network device; and a step in which the terminal device measures signal quality on links between the terminal device and one or more candidate relay terminals based on the measurement configuration information, and measures signal quality between the terminal device and a target access network device in one or more candidate cells. It should be understood that before the terminal device measures signal quality on links between the terminal device and one or more candidate relay terminals based on the measurement configuration information, the terminal device may first perform a relay discovery process. In other words, the terminal device needs to receive discovery messages sent by surrounding relay terminals, and then measure signal quality on links between the terminal device and one or more candidate relay terminals based on the discovery messages.

[0093] The measurement configuration information may include, for example, at least one of: the frequency of the cell to be measured by the terminal device, or the type of signal quality that needs to be measured by the terminal device.

[0094] Optionally, after step 301, if the source access network device determines the first candidate information list and / or the second candidate information list based on information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device, the first candidate information list and / or the second candidate information list is sent to the target access network device. The target access network device decides to hand over the terminal device to a direct link based on the first candidate information list and / or the second candidate information list, and the target access network device determines a target cell based on the second candidate information list; or the target access network device decides to hand over the terminal device to an indirect link based on the first candidate information list and / or the second candidate information list, and the target access network device determines a target relay terminal in the target cell based on the first candidate information list. Please refer to the solution shown in Figure 3A.

[0095] The first candidate information list includes information about one or more candidate relay terminals located in one or more cells served by the target access network device.

[0096] Optionally, the information about the candidate relay terminals in the first candidate information list may be, for example, information about all candidate relay terminals reported by the terminal device, or the information about the candidate relay terminals in the first candidate information list may be, for example, information about some candidate relay terminals among the candidate relay terminals reported by the terminal device. For example, the terminal device reports information about 10 candidate relay terminals to the source access network device, and the first candidate information list may include information about the 10 candidate relay terminals, or the first candidate information list may include information about 5 of the 10 candidate relay terminals.

[0097] It should be noted that in this application, the information about the candidate relay terminal in the first candidate information list may be identical or partially identical to the information about the corresponding candidate relay terminal reported by the terminal device. For example, the information about the candidate relay terminal A in the first candidate information list includes an identifier of the candidate relay terminal A, a signal quality on the link between the terminal device and the candidate relay terminal A, and an identifier of the serving cell of the candidate relay terminal A; the information about the candidate relay terminal A reported by the terminal device includes an identifier of the candidate relay terminal A, a signal quality on the link between the terminal device and the candidate relay terminal A, and an identifier of the serving cell of the candidate relay terminal A. Therefore, it can be seen that the information about the candidate relay terminal A in the first candidate information list is identical to the information about the candidate relay terminal A reported by the terminal device. For another example, the information about the candidate relay terminal A in the first candidate information list includes an identifier of the candidate relay terminal A and an identifier of a serving cell of the candidate relay terminal A; the information about the candidate relay terminal A reported by the terminal device includes an identifier of the candidate relay terminal A, a signal quality on a link between the terminal device and the candidate relay terminal A, and an identifier of a serving cell of the candidate relay terminal A. Therefore, it can be seen that the information about the candidate relay terminal A in the first candidate information list is partly identical to the information about the candidate relay terminal A reported by the terminal device.

[0098] Optionally, the arrangement order of the information about the candidate relay terminals in the first candidate information list may be determined by the source access network device based on the signal quality on the sidelink between the terminal device and the plurality of candidate relay terminals. For example, the arrangement order of the information about the candidate relay terminals in the first candidate information list may be determined by the source access network device by sorting the signal quality of the sidelink between the terminal device and the plurality of candidate relay terminals in descending order of signal quality. In another example, the arrangement order of the information about the candidate relay terminals in the first candidate information list may be determined by the source access network device by sorting the signal quality of the sidelink between the terminal device and the plurality of candidate relay terminals in ascending order of signal quality. It should be understood that the specific rule used by the source access network device to determine the arrangement order of the information about the candidate relay terminals in the first candidate information list may be predefined or fixed in a protocol, or may be negotiated by the target access network device and the source access network device. This is not intended to be limiting.

[0099] The second candidate information list includes information about one or more candidate cells served by the target access network device. Optionally, the information about candidate cells in the second candidate information list may be, for example, information about all candidate cells reported by the terminal device, or the information about candidate cells in the second candidate information list may be, for example, information about some candidate cells among the candidate cells reported by the terminal device. For example, the terminal device reports information about 10 candidate cells to the source access network device, and the second candidate information list may include information about the 10 candidate cells, or the second candidate information list may include information about 5 of the 10 candidate cells.

[0100] It should be noted that in the present application, the information about the candidate cell in the second candidate information list may be identical or partially identical to the information about the corresponding candidate cell reported by the terminal device. For example, the information about the candidate cell A in the second candidate information list includes the identifier of the candidate cell A, or the signal quality between the terminal device and the target access network device at the candidate cell A, and the identifier of the candidate cell A; the information about the candidate cell A reported by the terminal device includes the identifier of the candidate cell A, or the signal quality between the terminal device and the target access network device at the candidate cell A, and the identifier of the candidate cell A. Therefore, it can be seen that the information about the candidate cell A in the second candidate information list is identical to the information about the candidate cell A reported by the terminal device. In another example, the information about the candidate cell A in the second candidate information list includes the identifier of the candidate cell A and the identifier of the candidate cell A. Le B The information about the candidate cell A reported by the terminal device includes an identifier of the candidate cell A, or the signal quality between the terminal device and the target access network device at the candidate cell A and an identifier of the candidate cell A. Therefore, it can be seen that the information about the candidate cell A in the second candidate information list is partially identical to the information about the candidate cell A reported by the terminal device.

[0101] Optionally, the arrangement order of the information about the candidate cells in the second candidate information list may be determined by the source access network device based on the signal quality between the terminal device and the target access network device in one or more candidate cells. For example, the arrangement order of the information about the candidate cells in the second candidate information list may be determined by the source access network device by sorting the signal quality between the terminal device and the target access network device in one or more candidate cells in descending order of signal quality. In another example, the arrangement order of the information about the candidate cells in the second candidate information list may be determined by the source access network device by sorting the signal quality between the terminal device and the target access network device in one or more candidate cells in ascending order of signal quality. It should be understood that the specific rule used by the source access network device to determine the arrangement order of the information about the candidate cells in the second candidate information list may be predefined in a protocol, fixed, or negotiated by the target access network device and the source access network device. This is not intended to be limiting.

[0102] It should be noted that in this application, the first candidate information list may be referred to as a candidate relay UE info list, and the second candidate information list may be referred to as a candidate cell info list.

[0103] When the target access network device determines to hand over the terminal device to a direct link or an indirect link based on the first candidate information list and the second candidate information list, for example, when the signal quality on the SL between the terminal device and the candidate relay terminal in the first candidate information list is lower than the signal quality between the terminal device and the target access network device in the candidate cell in the second candidate information list, the target access network device determines to hand over the terminal device to the direct link. Alternatively, when the signal quality on the SL between the terminal device and the candidate relay terminal in the first candidate information list is lower than a predetermined value, the target access network device determines to hand over the terminal device to the direct link. Alternatively, when the signal quality on the SL between the terminal device and the candidate relay terminal in the first candidate information list is greater than or equal to a predetermined value, the target access network device determines to hand over the terminal device to the indirect link. The predetermined value may be predefined in a protocol, or may be a fixed value or the like. The present invention is not limited thereto.

[0104] Optionally, after step 301, the source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device, determines a first candidate information list, and sends the first candidate information list to the target access network device, where the target access network device determines a target relay terminal in the target cell. See the solution shown in Figure 3A. Alternatively, the source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, determines a first candidate information list, and sends the first candidate information list to the target access network device, where the target access network device determines a target relay terminal in the target cell. See the solution shown in Figure 3A.

[0105] When the source access network device decides to hand over the terminal device to a direct link based on the information about one or more candidate relay terminals reported by the terminal device and the information about one or more candidate cells reported by the terminal device, for example, the signal quality on the side link between the terminal device and the candidate relay terminal in the information about one or more candidate relay terminals reported by the terminal device is lower than the signal quality between the terminal device and the target access network device at the candidate cell in the information about one or more candidate cells reported by the terminal device, or alternatively, the source access network device decides to hand over the terminal device to an indirect link because the signal quality on the side link between the terminal device and the candidate relay terminal in the information about one or more candidate relay terminals reported by the terminal device is higher than or equal to the signal quality between the terminal device and the target access network device at the candidate cell in the information about one or more candidate cells reported by the terminal device.

[0106] Optionally, after step 301, if the source access network device decides to hand over the terminal device to a direct link and the source access network device determines the target cell, please refer to the solution shown in Figure 3B for details.

[0107] Optionally, after step 301, if the source access network device decides to hand over the terminal device to a direct link, but the target access network device decides the target cell, please refer to the solution shown in Figure 3C for details.

[0108] Optionally, after step 301, if the source access network device decides to hand over the terminal device to an indirect link, and the source access network device determines a target relay terminal in the target cell, please refer to the solution shown in Figure 3D for details.

[0109] Optionally, after step 301, if the source access network device decides to hand over the terminal device to an indirect link, and the source access network device determines the target cell, but the target access network device determines the target relay terminal in the target cell, please refer to the solution shown in Figure 3E for details.

[0110] Please refer to Fig. 3A. This embodiment of the present application further describes a solution in which a target access network device determines a target relay terminal in a target cell, and a solution in which a source access network device determines to hand over a terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, determines a first candidate information list, and sends the first candidate information list to the target access network device, and the target access network device determines a target relay terminal in the target cell.

[0111] 302A: The source access network device determines a first candidate information list and / or a second candidate information list based on information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device.

[0112] The source access network device determining a first candidate information list based on information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device may be understood as the source access network device determining the first candidate information list based on information about one or more candidate relay terminals reported by the terminal device, or the source access network device determining the first candidate information list based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device. The source access network device determining a second candidate information list based on information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device may be understood as the source access network device determining the second candidate information list based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, or the source access network device determining the second candidate information list based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device.

[0113] Optionally, step 302A may be replaced by the source access network device deciding to hand over the terminal device to an indirect link and determining the first candidate information list based on information about one or more candidate relay terminals reported by the terminal device; or the source access network device deciding to hand over the terminal device to an indirect link and determining the first candidate information list based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device.

[0114] 303A: A source access network device sends a first message to a target access network device, where the first message includes a first candidate information list and / or a second candidate information list.

[0115] In response, the target access network device receives a first message sent by the source access network device, where the first message may be, for example, a handover request message.

[0116] When the first message includes a first candidate information list, the first candidate information list includes information about multiple candidate relay terminals, which are located in one or more cells served by the target access network device. This means that the target access network device can recognize information necessary for handing over the terminal device to an indirect link, i.e., the first candidate information list. Therefore, the target access network device can decide to hand over the terminal device to an indirect link based on the first candidate information list. When the first message includes a second candidate information list, the second candidate information list includes information about one or more candidate cells served by the target access network device. This means that the target access network device can recognize information necessary for handing over the terminal device to a direct link, i.e., the second candidate information list. Therefore, the target access network device can decide to hand over the terminal device to a direct link. When the first message includes both the first candidate information list and the second candidate information list, the target access network device can recognize information necessary for handing over the terminal device to a direct link or an indirect link. Therefore, the target access network device can decide to hand over the terminal device to a direct link or an indirect link.

[0117] Optionally, the first message further includes a first identifier. The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device. The first identifier may be, for example, a target cell global identifier. It may be noted that the first message may be a handover request message, and the first identifier may be the target cell global identifier in the handover request message. This is equivalent to reusing the handover request message. This is compatible with existing protocols, may reduce impact on existing protocols, and may improve backward compatibility of the protocol.

[0118] In this application, the predefined identifier in the protocol may be, for example, a default identifier, which may be, for example, all 0 bits or all 1 bits.

[0119] Optionally, the identifiers of the cells recommended by the source access network device to the target access network device may include at least one of: identifiers of cells in which one or more of the candidate relay terminals reported by the terminal device are located, or identifiers of candidate cells reported by the terminal device.

[0120] For example, if the first message includes a first candidate information list, the first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device. Optionally, the identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located may be included in the first candidate information list. The identifier of the cell recommended by the source access network device to the target access network device may be the identifier of a cell in which one or more of the candidate relay terminals reported by the terminal device are located. In this case, in a possible implementation, the identifier of a cell in which one or more of the candidate relay terminals reported by the terminal device are located may be included in the first candidate information list.

[0121] In another example, when the first message includes the second candidate information list, the first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device. Optionally, the identifier of any candidate cell reported by the terminal device may be included in the second candidate information list. The identifier of the cell recommended by the source access network device to the target access network device may be the identifier of the candidate cell reported by the terminal device. In this case, in a possible implementation, information about the candidate cell reported by the terminal device may be included in the second candidate information list.

[0122] In another example, when the first message includes a first candidate information list and a second candidate information list, the first identifier includes at least one of: an identifier predefined in a protocol, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device. Optionally, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located may be included in the first candidate information list, and an identifier of any candidate cell reported by the terminal device may be included in the second candidate information list. An identifier of a cell recommended by the source access network device to the target access network device may include an identifier of a cell in which one or more of the candidate relay terminals reported by the terminal device are located and an identifier of the candidate cell reported by the terminal device. In this case, in a possible implementation, information about cells in which one or more of the candidate relay terminals reported by the terminal device are located may include the first candidate information list, and information about the candidate cell reported by the terminal device may be included in the second candidate information list.

[0123] In a possible implementation, the target access network device ignores the cell indicated by the first identifier if the first identifier includes at least one of: an identifier predefined in the protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, or a random value determined by the source access network device. Thus, the target access network device ignores the cell indicated by the first identifier when participating in the selection of the target relay terminal at the target cell or when participating in the selection of the target cell.

[0124] In another possible implementation, when the target access network device acquires the first candidate information list and / or the second candidate information list, the target access network device ignores the cell indicated by the first identifier. This means that regardless of what is indicated by the first identifier, the target access network device directly ignores the cell indicated by the first identifier, so that the target access network device does not refer to the cell indicated by the first identifier when participating in the selection of a target relay terminal in the target cell or when participating in the selection of a target cell. When the target access network device does not acquire the first candidate information list and does not acquire the second candidate information list, the first identifier is the identifier of the target cell to which the terminal device is handed over.

[0125] It should be noted that in this application, the target access network device ignoring the cell indicated by the first identifier may be understood as the target access network device ignoring or not referring to the cell indicated by the first identifier when the target access network device obtains the first message and the first message includes the first identifier. Furthermore, alternatively, it may be understood as the target access network device ignoring or not referring to the cell indicated by the first identifier when determining the target relay terminal or the target cell.

[0126] Optionally, the first message further includes first indication information, where the first indication information indicates that the first identifier is an identifier predefined in a protocol; or the first indication information indicates that the first identifier is an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is an identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is an identifier of a cell recommended by the source access network device to the target access network device; or the first indication information indicates that the first identifier is a random value determined by the source access network device. It may be seen that when the first identifier includes at least one of: an identifier predefined in the protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device, the target access network device can recognize the particular type of the first identifier by using the first indication information.

[0127] Optionally, when step 302A is replaced by the source access network device deciding to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and determining a first candidate information list, or when the source access network device deciding to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device and determining a first candidate information list, the first message in step 303A includes the first candidate information list.

[0128] Optionally, the solution may further include step 304A.

[0129] 304A: The target access network device determines first configuration information based on the first candidate information list and / or the second candidate information list, wherein the first configuration information is used by the terminal device to communicate with the target access network device through a first target relay terminal, and the first target relay terminal is one of a plurality of candidate relay terminals; or the first configuration information is used by the terminal device to communicate with the target access network device in a first target cell, and the first target cell is a cell in one or more candidate cells.

[0130] In the present application, use of first configuration information by a terminal device to communicate with a target access network device by using a first target relay terminal may be understood as use of the first configuration information by the terminal device to access a serving cell of the first target relay terminal and communicate with the target access network device through the first target relay terminal.

[0131] Optionally, when the first configuration information is used by the terminal device to communicate with the target access network device through the first target relay terminal, the first configuration information may include, for example, an end-to-end bearer configuration between the terminal device and the target access network device, an RLC bearer configuration between the terminal device and the first target relay terminal, and a mapping relationship between the end-to-end bearer and the RLC bearer.

[0132] In this application, an RLC bearer is a protocol entity and structure under the RLC layer, a lower layer part of the RB, and includes RLC layer entities and a set of resources such as logical channels. The RLC bearer can be classified as an RLC bearer between a terminal device and an access network device, and an RLC bearer between terminal devices.

[0133] In a possible implementation, before step 304A, the method may further include a step in which the target access network device determines a first target relay terminal based on the first candidate information list, where the first target relay terminal is one of a plurality of candidate relay terminals. This means that the target access network device can participate in selecting a target relay terminal in the target cell by using the first candidate information list. In other words, the target access network device can determine that the link to which the terminal device needs to be handed over is an indirect link. In this way, a better switching link can be selected for the terminal device, thereby increasing the success rate of link switching of the terminal device in a different access network device.

[0134] It should be understood that the first candidate information list includes information about multiple candidate relay terminals, where the multiple candidate relay terminals are located in one or more cells served by the target access network device, the serving cell of the first target relay terminal may be one of the one or more cells, and the first target relay terminal is one of the multiple candidate relay terminals. For example, the signal quality on the sidelink between the first target relay terminal and the terminal device may be the signal quality on the sidelink between the candidate relay terminal and the terminal device among the multiple candidate relay terminals, where the candidate relay terminal has the highest signal quality with the terminal device. For example, the first candidate information list includes information about three candidate relay terminals: information about candidate relay terminal 1, information about candidate relay terminal 2, and information about candidate relay terminal 3. The signal quality on the sidelink between candidate relay terminal 1 and the terminal device is higher than the signal quality on the sidelink between candidate relay terminal 2 and the terminal device. The signal quality on the sidelink between candidate relay terminal 1 and the terminal device is higher than the signal quality on the sidelink between candidate relay terminal 2 and the terminal device. end of 3rd year The signal quality on the sidelink between the candidate relay terminal 1 and the terminal device is higher than that on the sidelink between the candidate relay terminal 1 and the terminal device. Therefore, the candidate relay terminal 1 can be used as the first target relay terminal.

[0135] Optionally, if the first identifier is an identifier of a cell recommended by the source access network device to the target access network device, determining by the target access network device the first target relay terminal based on the first candidate information list includes: the target access network device determining the first target relay terminal based on the first candidate information list and a cell indicated by the first identifier. It should be understood that the identifier of the cell recommended by the source access network device to the target access network device is an identifier of a cell in which one or more of the candidate relay terminals reported by the terminal device are located.

[0136] In another possible implementation, before step 304A, the method may further include the step of the target access network device determining a first target cell based on the second candidate information list. This means that the target access network device may further participate in selecting a target cell by using the second candidate information list. In other words, the target access network device may determine that the link to which the terminal device needs to be handed over is a direct link. In this way, a better switching link can be selected for the terminal device, thereby increasing the success rate of link switching of the terminal device in different access network devices.

[0137] Optionally, if the first identifier is an identifier of a cell recommended by the source access network device to the target access network device, determining by the target access network device the first target cell based on the second candidate information list includes: the target access network device determining the first target cell based on the second candidate information list and a cell indicated by the first identifier. It should be understood that the identifier of the cell recommended by the source access network device to the target access network device is the identifier of the candidate cell reported by the terminal device.

[0138] It should be understood that the second candidate information list includes information about one or more candidate cells served by the target access network device, and the first target cell is a cell in one or more candidate cells. For example, the signal quality between the terminal device and the target access network device in the first target cell may be the highest signal quality between the terminal device and the target access network device in one or more candidate cells. For example, the second candidate information list includes information about three candidate cells: information about candidate cell 1, information about candidate cell 2, and information about candidate cell 3. The signal quality between the terminal device and the target access network device in candidate cell 1 is higher than the signal quality between the terminal device and the target access network device in candidate cell 2, and the signal quality between the terminal device and the target access network device in candidate cell 2 is higher than the signal quality between the terminal device and the target access network device in candidate cell 3. Therefore, candidate cell 1 can be used as the first target cell.

[0139] Optionally, the target access network device may further generate first configuration information by referring to first information from the source access network device. The first information may be used, for example, by a terminal device to communicate with the source access network device. Specifically, the first information may include, for example, an end-to-end bearer configuration between the terminal device and the source access network device, and a configuration required by the terminal device to access the source access network device through random access. Alternatively, the first information may be used, for example, by a terminal device to communicate with the source access network device through a relay terminal, and the first information may include, for example, an end-to-end bearer configuration between the terminal device and the source access network device, an RLC bearer configuration between the terminal device and the relay terminal, and a mapping relationship between the end-to-end bearer and the RLC bearer.

[0140] Optionally, when step 302A is replaced by the source access network device deciding to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and determining a first candidate information list, or when the source access network device deciding to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device and determining a first candidate information list, step 304A may be replaced by the target access network device determining first configuration information based on the first candidate information list, wherein the first configuration information is used by the terminal device to communicate with the target access network device through the first target relay terminal.

[0141] Optionally, the solution provided in this embodiment may further include step 305A.

[0142] 305A: The source access network device receives first configuration information sent by the target access network device.

[0143] In response, the target access network device sends first configuration information to the source access network device, where the first configuration information may be carried in a response message to the first message, and the response message to the first message may be a handover request acknowledge message, for example.

[0144] Optionally, when the target access network device decides to handover the terminal device to the indirect link, after the target access network device sends the first configuration information to the source access network device, the method may further comprise: the target access network device sending a radio resource control relaying reconfiguration message to the first target relay terminal. The radio resource control relaying reconfiguration message is used by the first target relay terminal to establish a bearer through which the terminal device communicates with the target access network device through the first target relay terminal. The radio resource control relaying reconfiguration message includes at least one of: an RLC bearer configuration between the terminal device and the first target relay terminal, an RLC bearer configuration between the first target relay terminal and the target access network device, or an end-to-end bearer configuration between the terminal device and the target access network device and a mapping relationship between the RLC bearers.

[0145] 306A: The terminal device receives first configuration information sent by the source access network device.

[0146] In response, the source access network device sends first configuration information to the terminal device, where the first configuration information may be carried in, for example, a radio resource control reconfiguration message (RRC reconfiguration message).

[0147] 307A: The terminal device communicates with the target access network device based on the first configuration information.

[0148] In a possible implementation, step 307A may include, for example, the terminal device communicating with the target access network device through the first target relay terminal based on the first configuration information. It should be understood that before the terminal device communicates with the target access network device through the first target relay terminal based on the first configuration information, the method may further include: if the terminal device does not establish a link with the first target relay terminal, the terminal device establishing a link with the first target relay terminal and transmitting a radio resource control reconfiguration complete message (RRC reconfiguration complete message) to the first target relay terminal over the link. When establishing an associated bearer based on the radio resource control relay reconfiguration message, the first target relay terminal forwards the radio resource control reconfiguration complete message to the target access network device. The radio resource control reconfiguration complete message indicates that the terminal device has successfully established a bearer for communicating with the target access network device through the first target relay terminal.

[0149] In another possible implementation, step 307A may include, for example: the terminal device communicating with the target access network device in the first target cell based on the first configuration information. It should be understood that before the terminal device communicates with the target access network device in the first target cell based on the first configuration information, the method may further include: the terminal device accessing the first target cell through random access and sending a radio resource control reconfiguration complete message to the target access network device, where the radio resource control reconfiguration complete message indicates successful establishment of a bearer between the terminal device and the target access network device in the first target cell.

[0150] It can be seen that in the solution provided in this embodiment, when the source access network device does not make a decision and the target access network device decides to hand over the terminal device to a direct link or an indirect link, the target access network device can participate in selecting a target relay terminal in the target cell by using the first candidate information list from the source access network device, or the target access network device can participate in selecting a target cell by using the second candidate information list from the source access network device. In this way, a better switching link can be selected for the terminal device, so as to increase the success rate of link switching of the terminal device in different access network devices.

[0151] See Figure 3B. The embodiment of the present application further describes a solution in which the source access network device decides to hand over the terminal device to a direct link, and the source access network device decides the target cell.

[0152] 302B: The source access network device decides to hand over the terminal device to a direct link and determines a second target cell based on information about one or more candidate cells reported by the terminal device; or the source access network device decides to hand over the terminal device to a direct link and determines a second target cell based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device.

[0153] Optionally, the signal quality between the terminal device and the target access network device in the second target cell may be, for example, the highest signal quality in the information about one or more candidate cells reported by the terminal device.

[0154] 303B: The source access network device sends a second message to the target access network device, where the second message includes an identifier of the second target cell, and the second message is used to request the target access network device to allow the terminal device to communicate with the target access network device in the second target cell. In response, the target access network device receives the second message sent by the source access network device. The second message may be, for example, a handover request message.

[0155] The identifier of the second target cell may be, for example, a target cell global identifier.

[0156] 304B: The target access network device sends a second message response message to the source access network device, where the second message response message includes second configuration information, the second configuration information is used by the terminal device to communicate with the target access network device in the second target cell, and the second message response message indicates that the terminal device is allowed to communicate with the target access network device in the second target cell.

[0157] In response, the source access network device receives a response message for the second message sent by the target access network device, where the response message for the second message may be, for example, a handover request acknowledgement message.

[0158] The second configuration information is similar to the first configuration information used by the terminal device to communicate with the target access network device in the first target cell in the solution in the embodiment described in Figure 3A, and the details will not be described again here.

[0159] 305B: The terminal device receives second configuration information sent by the source access network device.

[0160] In response, the source access network device transmits second configuration information to the terminal device, which may be carried in, for example, a radio resource control reconfiguration message.

[0161] 306B: The terminal device communicates with the target access network device in the second target cell based on the second configuration information.

[0162] Step 306B is similar to step 306A in which the terminal device communicates with the target access network device in the first target cell based on the first configuration information, and the details will not be described again here.

[0163] In this embodiment, when the source access network device determines to hand over the terminal device to a direct link based on information about one or more candidate cells reported by the terminal device, or when the source access network device determines to hand over the terminal device to a direct link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, it can be seen that the source access network device may be involved in selecting a target cell based on the information about one or more candidate cells reported by the terminal device. In addition, after determining the target cell, the source access network device may request the target access network device to allow the terminal device to communicate with the target access network device in a second target cell, so that the terminal device can communicate with the target access network device in the second target cell after being allowed, thereby increasing the success rate of link switching of the terminal device in a different access network device.

[0164] See Figure 3C. The embodiment further describes a solution in which the source access network device decides to hand over the terminal device to a direct link, but the target access network device decides the target cell.

[0165] 302C: The source access network device decides to hand over the terminal device to a direct link based on information about one or more candidate cells reported by the terminal device, and determines a third candidate information list; or the source access network device decides to hand over the terminal device to a direct link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, and determines a third candidate information list.

[0166] The third candidate information list is similar to the second candidate information list in the solution of the embodiment shown in Figure 3A, and the details will not be described again here.

[0167] 303C: The source access network device sends a third message to the target access network device, where the third message includes a third candidate information list.

[0168] In response, the target access network device receives a third message sent by the source access network device, where the third message may be, for example, a handover request message.

[0169] Optionally, the third message further includes a second identifier. The second identifier includes at least one of: an identifier predefined in a protocol, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device. The third message may, for example, be a handover request message. The second identifier may, for example, be a target cell global identifier in the handover request message. This is equivalent to reusing the handover request message. This is compatible with existing protocols, may reduce impact on existing protocols, and may improve backward compatibility of the protocol.

[0170] Optionally, the identifier of the cell recommended by the source access network device to the target access network device may be the identifier of the candidate cell reported by the terminal device. In a possible implementation, the information about the candidate cell reported by the terminal device may be included in the third candidate information list.

[0171] In a possible implementation, the target access network device ignores the cell indicated by the second identifier if the second identifier includes at least one of: an identifier predefined in the protocol, an identifier of any candidate cell reported by the terminal device, or a random value determined by the source access network device. Thus, when participating in the selection of the target cell, the target access network device ignores the cell indicated by the second identifier.

[0172] In another possible implementation, if the target access network device acquires the third candidate information list, the target access network device ignores the cell indicated by the second identifier. This means that regardless of what is indicated by the second identifier, the target access network device directly ignores the cell indicated by the second identifier, and as a result, the target access network device does not refer to the cell indicated by the second identifier when participating in target cell selection. If the target access network device does not acquire the third candidate information list, the second identifier is the identifier of the target cell to which the terminal device is handed over.

[0173] It should be noted that in this application, the target access network device ignoring the cell indicated by the second identifier may be understood as the target access network device ignoring or not referring to the cell indicated by the second identifier when the target access network device obtains the third message and the third message includes the second identifier. Furthermore, alternatively, it may be understood as the target access network device ignoring or not referring to the cell indicated by the second identifier when determining the target relay terminal or the target cell.

[0174] Optionally, the third message further includes second indication information. The second indication information indicates that the second identifier is an identifier predefined in a protocol, or the second indication information indicates that the second identifier is an identifier of any candidate cell reported by the terminal device, or the second indication information indicates that the second identifier is an identifier of a cell recommended by the source access network device to the target access network device, or the second indication information indicates that the second identifier is a random value determined by the source access network device. It may be found that when the second identifier includes at least one of: an identifier predefined in a protocol, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device, the target access network device can recognize a specific type of the second identifier by using the second indication information.

[0175] 304C: The target access network device determines third configuration information based on the third candidate information list, where the third configuration information is used by the terminal device to communicate with the target access network device in the third target cell.

[0176] Step 304C is similar to step 304A in which the target access network device determines the first target cell based on the second candidate information list, and the details will not be repeated here.

[0177] The third configuration information is similar to the first configuration information used by the terminal device to communicate with the target access network device in the first target cell in the solution shown in Figure 3A, and the details will not be described again here.

[0178] 305C: The source access network device receives third configuration information sent by the target access network device.

[0179] In response, the target access network device sends third configuration information to the source access network device, where the third configuration information may be, for example, carried in a third message response message, and the third message response message may be, for example, a handover request acknowledgement message.

[0180] 306C: The terminal device receives third configuration information sent by the source access network device.

[0181] In response, the source access network device sends third configuration information to the terminal device, where the third configuration information may be carried in a radio resource control reconfiguration message, for example.

[0182] 307C: The terminal device communicates with the target access network device in the third target cell based on the third configuration information.

[0183] For step 307C, please refer to step 306B, and the details will not be repeated here.

[0184] In the solution shown in this embodiment, when the source access network device decides to hand over the terminal device to a direct link based on information about one or more candidate cells reported by the terminal device, or when the source access network device decides to hand over the terminal device to a direct link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, it can be seen that the target access network device can participate in the selection of the target cell by using a third candidate information list from the source access network device, which can increase the success rate of link switching of the terminal device to a different access network device.

[0185] See Figure 3D. The embodiment of the present application further provides a solution in which the source access network device decides to hand over the terminal device to an indirect link, and the source access network device decides the target relay terminal in the target cell.

[0186] 302D: The source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device, and determines a target relay terminal in a fourth target cell; or the source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, and determines a target relay terminal in a fourth target cell.

[0187] Optionally, the signal quality on the sidelink between the target relay terminal in the fourth target cell and the terminal device may be the highest signal quality in the information about one or more candidate relay terminals reported by the terminal device.

[0188] 303D: The source access network device sends a fourth message to the target access network device, where the fourth message includes an identifier in the fourth target cell and an identifier of the target relay terminal in the fourth target cell, and the fourth message is used to request the target access network device to allow the terminal device to communicate with the target access network device through the target relay terminal in the fourth target cell.

[0189] In response, the target access network device receives a fourth message sent by the source access network device, which may be, for example, a handover request message.

[0190] In a possible implementation, the identifier of the fourth target cell may be, for example, a target cell global identifier, and the identifier of the target relay terminal in the fourth target cell may be, for example, a target relay terminal identifier (target relay UE ID). In this way, identifiers defined in existing protocols are used, thereby reducing the impact on existing protocols.

[0191] In another possible implementation, the identifier of the fourth target cell may be, for example, a predetermined target cell identifier; and the identifier of the target relay terminal in the fourth target cell may be, for example, a predetermined target relay terminal identifier. The predetermined target cell identifier and the predetermined target relay terminal identifier may be, for example, identifiers newly added to the fourth message. In this case, the fourth message may further include a third identifier. The third identifier may include at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, or a random value determined by the source access network device. It should be understood that if the target access network device acquires the predetermined target cell identifier and the third identifier, or if the target access network device acquires the third identifier, the target access network device ignores the cell indicated by the third identifier. The third identifier may be, for example, a target cell global identifier. It may be understood that the fourth message may be a handover request message, and the third identifier may be a target cell global identifier in the handover request message. This is equivalent to reusing the handover request message, which is compatible with existing protocols, reduces the impact on existing protocols, and may improve backward compatibility of protocols. In addition, when participating in the selection of a target relay terminal in the target cell or when participating in the selection of a target cell, the target access network device does not refer to the cell indicated by the third identifier.

[0192] It should be noted that in this application, the target access network device ignoring the cell indicated by the third identifier may be understood as the target access network device ignoring or not referring to the cell indicated by the third identifier when the target access network device obtains the fourth message and the fourth message includes the third identifier. Furthermore, alternatively, it may be understood as the target access network device ignoring or not referring to the cell indicated by the third identifier when determining the target relay terminal or the target cell.

[0193] 304D: The target access network device sends a fourth message response message to the source access network device, where the fourth message response message includes fourth configuration information, the fourth configuration information is used by the terminal device to communicate with the target access network device through the target relay terminal in the fourth target cell, and the fourth message response message indicates that the terminal device is allowed to communicate with the target access network device through the target relay terminal in the fourth target cell.

[0194] In response, the source access network device receives a response message of the fourth message sent by the target access network device, where the response message of the fourth message may be, for example, a handover request acknowledgement message.

[0195] The fourth configuration information is similar to the first configuration information used by the terminal device to communicate with the target access network device through the first target relay terminal in the solution shown in Figure 3A, and the details will not be described again here.

[0196] 305D: The terminal device receives the fourth configuration information sent by the source access network device.

[0197] In response, the source access network device sends fourth configuration information to the terminal device, which may be carried in, for example, a radio resource control reconfiguration message.

[0198] 306D: The terminal device communicates with the target access network device through the target relay terminal in the fourth target cell based on the fourth configuration information.

[0199] Step 306D is similar to step 306A in which the terminal device communicates with the target access network device through the first target relay terminal based on the first configuration information, and the details will not be described again here.

[0200] In the solution shown in this embodiment, when the source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device, or when the source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, it can be seen that the source access network device can be involved in selecting a target relay terminal in a target cell based on information about one or more candidate cells reported by the terminal device. In addition, after determining the target relay terminal in the target cell, the source access network device can request the target access network device to allow the terminal device to communicate with the target access network device through the target relay terminal in the fourth target cell, so that the terminal device can communicate with the target access network device through the target relay terminal in the fourth target cell after being allowed, thereby increasing the success rate of link switching of the terminal device in a different access network device.

[0201] See Figure 3E. The embodiments of the present application further describe a solution in which a source access network device determines to hand over a terminal device to an indirect link, the source access network device determines a target cell, and the target access network device determines a target relay terminal in the target cell.

[0202] 302E: The source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device, and determines information about one or more candidate relay terminals in a fifth target cell; or the source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, and determines information about one or more candidate relay terminals in the fifth target cell.

[0203] It should be understood that the one or more candidate relay terminals in the fifth target cell may be, for example, all candidate relay terminals in the fifth target cell among one or more candidate relay terminals reported by the terminal device, or may be some candidate relay terminals in the fifth target cell among one or more candidate relay terminals reported by the terminal device, without being limited thereto herein.

[0204] 303E: The source access network device sends a fifth message to the target access network device, where the fifth message includes information about one or more candidate relay terminals in the fifth target cell.

[0205] In response, the target access network device receives a fifth message sent by the source access network device, where the fifth message may be, for example, a handover request message.

[0206] It should be understood that the fifth message includes information about one or more candidate relay terminals in the fifth target cell, which indicates that the source access network device has selected the target cell, but the target relay terminal device needs to be determined by the target access network device.

[0207] The fifth message may further include a fourth identifier.

[0208] In a possible implementation, the fourth identifier is the identifier of the fifth target cell. In this way, an identifier defined in an existing protocol is used, thereby reducing the impact on the existing protocol.

[0209] In another possible implementation, information about one or more candidate relay terminals in the fifth target cell is included in a fourth candidate information list. The fourth identifier may include at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by a terminal device is located, an identifier of any candidate cell reported by a terminal device, or a random value determined by a source access network device. It should be understood that when a target access network device acquires the fourth candidate information list, or when a target access network device acquires the fourth candidate information list and the fourth identifier, the target access network device ignores the cell indicated by the fourth identifier. In addition, when the fourth identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by a terminal device is located, an identifier of any candidate cell reported by a terminal device, or a random value determined by a source access network device, the target access network device also ignores the cell indicated by the fourth identifier. The fourth identifier may be, for example, a target cell global identifier. It may be understood that when information about one or more candidate relay terminals in the fifth target cell is included in the fourth candidate information list, the fourth identifier may be a target cell global identifier in the handover request message. This is equivalent to reusing the handover request message. This may be compatible with existing protocols, reduce the impact on existing protocols, and improve backward compatibility of protocols. In addition, when participating in the selection of a target relay terminal of the target cell, the target access network device does not refer to the cell indicated by the fourth identifier.

[0210] It should be noted that in this application, the target access network device ignoring the cell indicated by the fourth identifier may be understood as the target access network device ignoring or not referring to the cell indicated by the fourth identifier when the target access network device obtains the fifth message and the fifth message includes the fourth identifier. Furthermore, alternatively, it may be understood as the target access network device ignoring or not referring to the cell indicated by the fourth identifier when determining the target relay terminal or the target cell.

[0211] 304E: The target access network device determines a target relay terminal in the fifth target cell based on information about one or more relay terminals in the fifth target cell, and sends fifth configuration information to the source access network device, where the fifth configuration information is used by the terminal device to communicate with the target access network device through the target relay terminal in the fifth target cell.

[0212] In response, the source access network device receives fifth configuration information sent by the target access network device.

[0213] The fifth configuration information may be carried in, for example, a response message of the fifth message, which may be, for example, a handover request acknowledgement message.

[0214] The fifth configuration information is similar to the first configuration information used by the terminal device to communicate with the target access network device through the first target relay terminal in the solution shown in Figure 3A, and the details will not be described again here.

[0215] 305E: The terminal device receives the fifth configuration information sent by the source access network device.

[0216] In response, the source access network device sends fifth configuration information to the terminal device, which may be carried in, for example, a radio resource control reconfiguration message.

[0217] 306E: The terminal device communicates with the target access network device through the target relay terminal in the fifth target cell based on the fifth configuration information.

[0218] Step 306E is similar to step 306A in which the terminal device communicates with the target access network device through the first target relay terminal based on the first configuration information, and the details will not be described again here.

[0219] In the solution shown in this embodiment, when the source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device, or when the source access network device decides to hand over the terminal device to an indirect link based on information about one or more candidate relay terminals reported by the terminal device and information about one or more candidate cells reported by the terminal device, it can be seen that the source access network device can determine information about one or more candidate relay terminals in a fifth target cell based on information about one or more candidate cells reported by the terminal device, and transmit the information about the one or more candidate relay terminals in the fifth target cell to the target access network device. This means that the source access network device can determine the target cell, and the target access network device can determine the target relay terminal in the target cell, so that the target access network device can participate in selecting the target relay terminal. In this way, a better target relay terminal can be selected for the terminal device.

[0220] The above description of the solutions provided in the present application has been mainly focused on interactions between devices. In the above implementations, it can be understood that, to implement the above functions, each device includes a corresponding hardware structure and / or software module for performing each function. Those skilled in the art will readily recognize that, in combination with the example units and algorithm steps described in the embodiments disclosed herein, the present application can be implemented by hardware or a combination of hardware and computer software. Whether a function is performed by hardware or hardware driven by computer software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use multiple different methods to implement the described functions for each specific application, but such implementations should not be considered to exceed the scope of the present application.

[0221] In the embodiments of the present application, the target access network device, the source access network device, or the terminal device may be divided into functional modules based on the above method examples. For example, each functional module may be obtained by division based on the corresponding function, or two or more functions may be integrated into one processing module. The integrated module may be implemented in the form of hardware or in the form of a software function module. It should be noted that the module division in the embodiments of the present application is an example and is merely a logical functional division. During actual implementation, other division methods may be used.

[0222] If an integrated module is used, please refer to FIG. 4. FIG. 4 is a structural diagram of a communication device according to an embodiment of the present application. The communication device 400 can be used in any one of the methods shown in FIGS. 3A to 3E. As shown in FIG. 4, the communication device 400 includes a processing module 401 and a transceiver module 402. The processing module 401 can be one or more processors, and the transceiver module 402 can be a transceiver or a communication interface. The communication device can be configured to implement a target access network device, a source access network device, or a terminal device in any one of the above method embodiments, or can be configured to implement the function of a network element in any one of the above method embodiments. The network element or network function can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualization function instantiated on a platform (e.g., a cloud platform). Optionally, the communication device 400 can further include a storage module 403 configured to store program codes and data of the communication device 400.

[0223] In a possible implementation, when the communication device is used as a target access network device or a chip used in a target access network device, the communication device performs the steps performed by the target access network device in the above-described method embodiments. The transceiver module 402 is configured to support communication with a source access network device, a terminal device, a relay terminal, or the like. The transceiver module specifically performs the transmitting and / or receiving operations performed by the target access network device in any one of the embodiments in FIGS. 3A-3E, and supports the target access network device in performing one or more steps, such as step 305A and step 304B, and / or another process of the technology described herein. The processing module 401 may be configured to support the communication device 400 in performing the processing operations in the above-described method embodiments, such as one or more steps, such as step 304A and step 304C, and / or support the target access network device in performing another process of the technology described herein.

[0224] Specifically, the transceiver module 402 is configured to receive a first message sent by a source access network device, where the first message includes a first candidate information list and / or a second candidate information list; the first candidate information list includes information about a plurality of candidate relay terminals, where the plurality of candidate relay terminals are located in one or more cells served by the target access network device; and the second candidate information list includes information about one or more candidate cells served by the target access network device. The processing module 401 is configured to determine first configuration information based on the first candidate information list and / or the second candidate information list, where the first configuration information is used by the terminal device to communicate with the target access network device through a first target relay terminal, where the first target relay terminal is one of the plurality of candidate relay terminals; or the first configuration information is used by the terminal device to communicate with the target access network device in a first target cell, where the first target cell is a cell in one or more candidate cells. The target access network device transmits the first configuration information to the source access network device.

[0225] Optionally, the processing module 401 is further configured to determine a first target relay terminal based on the first candidate information list, where a serving cell of the first target relay terminal is one of the one or more cells.

[0226] Optionally, the processing module 401 is further configured to determine the first target cell based on the second candidate information list.

[0227] Optionally, the first message further includes a first identifier, which includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device.

[0228] Optionally, the processing module 401 is further configured to ignore the cell indicated by the first identifier if the first identifier includes at least one of: an identifier predefined in the protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, or a random value determined by the source access network device.

[0229] Optionally, when the target access network device obtains the first candidate information list and / or the second candidate information list, the processing module 401 is further configured to ignore the cell indicated by the first identifier.

[0230] Optionally, when determining the first target relay terminal based on the first candidate information list, if the first identifier is an identifier of a cell recommended by the source access network device to the target access network device, the processing module 401 is configured to determine the first target relay terminal based on the first candidate information list and the cell indicated by the first identifier.

[0231] Optionally, when determining the first target cell based on the second candidate information list, if the first identifier is an identifier of a cell recommended by the source access network device to the target access network device, the processing module 401 is configured to determine the first target cell based on the second candidate information list and the cell indicated by the first identifier.

[0232] Optionally, the first message further includes first indication information, where the first indication information indicates that the first identifier is an identifier predefined in a protocol; or the first indication information indicates that the first identifier is an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is an identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is an identifier of a cell recommended by the source access network device to the target access network device; or the first indication information indicates that the first identifier is a random value determined by the source access network device.

[0233] In a possible implementation, when the communication device is used as a source access network device or a chip used in a source access network device, the communication device performs the steps performed by the source access network device in the above-described method embodiments. The transceiver module 402 is configured to support communication with a target access network device, a terminal device, a relay terminal, or the like. The transceiver module specifically performs the transmitting and / or receiving operations performed by the source access network device in any one of the embodiments in FIGS. 3A-3E, for example, to support the source access network device in performing one or more steps, such as step 303A and step 303B, and / or another process of the technology described herein. The processing module 401 may be configured to support the communication device 400 in performing the processing operations in the above-described method embodiments, for example, to support the source access network device in performing one or more steps, such as step 302A and step 302B, and / or another process of the technology described herein.

[0234] Specifically, the transceiver module 402 is configured to receive information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device. The processing module 401 is configured to determine a first candidate information list and / or a second candidate information list based on the information about one or more candidate relay terminals reported by the terminal device and / or information about one or more candidate cells reported by the terminal device. The first candidate information list includes information about multiple candidate relay terminals, which are located in one or more cells served by the target access network device. The second candidate information list includes information about one or more candidate cells served by the target access network device. The transceiver module 402 is further configured to send a first message to the target access network device. The first message includes the first candidate information list and / or the second candidate information list. The transceiver module 402 is further configured to receive first configuration information sent by the target access network device. The first configuration information is used by the terminal device to communicate with the target access network device through a first target relay terminal, where the first target relay terminal is one of a plurality of candidate relay terminals; or the first configuration information is used by the terminal device to communicate with the target access network device in a first target cell, where the first target cell is a cell in one or more candidate cells. The transceiver module 402 is further configured to transmit the first configuration information to the terminal device.

[0235] Optionally, the first message further includes a first identifier, which includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device.

[0236] Optionally, the first message further includes first indication information, where the first indication information indicates that the first identifier is an identifier predefined in a protocol; or the first indication information indicates that the first identifier is an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is an identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is an identifier of a cell recommended by the source access network device to the target access network device; or the first indication information indicates that the first identifier is a random value determined by the source access network device.

[0237] In a possible implementation, when the communication device is used as a terminal device or a chip used in a terminal device, the communication device performs the steps performed by the terminal device in the above-described method embodiments. The transceiver module 402 is configured to support communication with a target access network device, a source access network device, a relay terminal, or the like. The transceiver module specifically performs the transmitting and / or receiving operations performed by the terminal device in any one of the embodiments in FIGS. 3A-3E, for example, to support the terminal device in performing one or more steps, such as step 301 and step 306A, and / or another process of the technology described herein. The processing module 401 may be configured to support the communication device 400 in performing the processing operations in the above-described method embodiments, for example, to support the terminal device in performing one or more steps, such as step 307A and step 306B, and / or another process of the technology described herein.

[0238] Specifically, the transceiver module 402 is configured to report information about one or more candidate relay terminals and / or information about one or more candidate cells to the source access network device. The transceiver module 402 is further configured to receive first configuration information sent by the source access network device. The processing module 401 is configured to communicate with the target access network device through a first target relay terminal based on the first configuration information, or to communicate with the target access network device in the first target cell based on the first configuration information. The first configuration information is determined by the target access network device based on a first message sent by the source access network device. The first message includes a first candidate information list and / or a second candidate information list. The first candidate information list is determined by the source access network device based on information about one or more candidate relay terminals reported by the terminal device. The second candidate information list is determined by the source access network device based on information about one or more candidate cells reported by the terminal device. The first candidate information list includes information about multiple candidate relay terminals. The multiple candidate relay terminals are located in one or more cells served by the target access network device. The first target relay terminal is one of a plurality of candidate relay terminals. The second candidate information list includes information about one or more candidate cells served by the target access network device. The first target cell is a cell in the one or more candidate cells.

[0239] Optionally, the first message further includes a first identifier, which includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the source access network device to the target access network device, or a random value determined by the source access network device.

[0240] Optionally, the first message further includes first indication information, where the first indication information indicates that the first identifier is an identifier predefined in a protocol; or the first indication information indicates that the first identifier is an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is an identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is an identifier of a cell recommended by the source access network device to the target access network device; or the first indication information indicates that the first identifier is a random value determined by the source access network device.

[0241] In a possible implementation, when the target access network device, the source access network device, or the terminal device is a chip, the transceiver module 402 may be a communication interface, pin, circuit, or the like. The communication interface may be configured to input data to be processed into a processor and output the processing result of the processor to the outside. In a specific implementation, the communication interface may be a general-purpose input / output (GPIO) interface and may be connected to multiple peripheral devices (e.g., a display (LCD), a camera (camera), a radio frequency (RF) module, and an antenna). The communication interface is connected to the processor through a bus.

[0242] The processing module 401 may be a processor. The processor may execute computer-executable instructions stored in the storage module, so that the chip performs the method according to any one of the embodiments in Figures 3A to 3E.

[0243] Further, a processor may include a controller, an arithmetic unit, and a register. For example, the controller is mainly responsible for decoding instructions and transmitting control signals for operations corresponding to the instructions. The arithmetic unit is mainly responsible for performing fixed-point or floating-point arithmetic operations, shift operations, logical operations, and the like, and may also perform address manipulation and address translation. The register is mainly responsible for saving a number of register operations, intermediate operation results, and the like that are temporarily stored during instruction execution. In a specific implementation, the hardware architecture of the processor may be an application-specific integrated circuit (ASIC) architecture, a microprocessor without interlocked piped stages architecture (MIPS), an advanced reduced instruction set computing machine (ARM) architecture, a network processor (NP) architecture, or the like. The processor may be a single-core or multi-core processor.

[0244] The storage module may be a storage module within the chip, such as a register or cache, or alternatively, may be a storage module located outside the chip, such as a read-only memory (ROM), another type of static storage device capable of storing static information and instructions, or a random access memory (RAM).

[0245] It should be noted that the functions corresponding to each of the processor and the interface may be implemented using a hardware design, a software design, or a combination of software and hardware, but is not limited thereto.

[0246] FIG. 5 is a simplified diagram of the structure of a terminal device according to an embodiment of the present application. For ease of understanding and description, a mobile phone is used as an example of the terminal device in FIG. 5. As shown in FIG. 5, the terminal device includes at least one processor and may further include a radio frequency circuit, an antenna, and an input / output device. The processor may be configured to process communication protocols and communication data, and may further be configured to control the terminal device, execute software programs, process data of the software programs, etc. The terminal device may further include a memory. The memory is mainly configured to store software programs and data. These related programs may be loaded into the memory when the communication device is delivered from the factory, or may be loaded into the memory later when needed. The radio frequency circuit is mainly configured to perform conversion between baseband signals and radio frequency signals and process the radio frequency signals. The antenna is mainly configured to receive / transmit radio frequency signals in the form of electromagnetic waves, and the antenna is provided in the embodiment of the present application. The input / output device, such as a touch screen, a display, or a keyboard, is mainly configured to receive data input by a user and output data to the user. It should be noted that some types of terminal devices may not include input / output devices.

[0247] When data needs to be transmitted, after performing baseband processing on the data to be transmitted, the processor outputs the baseband signal to the radio frequency circuit; the radio frequency circuit performs radio frequency processing on the baseband signal, and then transmits the radio frequency signal to the outside in the form of electromagnetic waves through an antenna. When data is transmitted to the terminal device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data. For ease of explanation, FIG. 5 shows only one memory and one processor. In an actual terminal device product, there may be one or more processors and one or more memories. The memory may also be referred to as a storage medium, a storage device, or the like. The memory may be located independently of the processor or integrated with the processor. This is not a limitation of this embodiment of the present application.

[0248] In this embodiment of the present application, an antenna having transmitting and receiving functions and a radio frequency circuit may be regarded as a receiving unit and a transmitting unit (which may also be collectively referred to as a transceiver unit) of a terminal device, and a processor having a processing function may be regarded as a processing unit of the terminal device. As shown in FIG. 5, the terminal device includes a receiving module 31, a processing module 32, and a transmitting module 33. The receiving module 31 may also be referred to as a receiver, a receiver, a receiving circuit, or the like. The transmitting module 33 may also be referred to as a transmitter, a transmitter, a transmitting circuit, or the like. The processing module 32 may also be referred to as a processor, a processing board, a processing device, or the like.

[0249] For example, the processing module 32 is configured to perform the functions of the terminal device in any one of the embodiments in FIGS. 3A to 3E.

[0250] FIG. 6 is a simplified diagram of the structure of an access network device according to an embodiment of the present application. The access network device includes a baseband unit 42 and a unit for radio frequency signal transmission / reception and conversion. The unit for radio frequency signal transmission / reception and conversion further includes a receiving module 41 and a transmitting module 43 (which may be collectively referred to as a transceiver module). The radio frequency signal transmission / reception and conversion unit is mainly configured to transmit / receive radio frequency signals and perform conversion between radio frequency signals and baseband signals. The baseband unit 42 is mainly configured to perform baseband processing, control the access network device, etc. The receiving module 41 may also be referred to as a receiver, receiver circuit, or the like. The transmitting module 43 may also be referred to as a transmitter, transmitter, transmitter circuit, or the like. The baseband unit 42 is typically the control center of the access network device and may also be referred to as a processing module, and is configured to execute steps performed by the access network device (e.g., a target access network device or a source access network device) in any one of the embodiments in FIGS. 3A to 3E. For details, please refer to the relevant parts above.

[0251] The baseband unit 42 may include one or more boards. Each board may include one or more processors and one or more memories. The processors are configured to read and execute programs in the memories to implement baseband processing functions and control the access network devices. When there are multiple boards, the boards may be interconnected to improve processing capabilities. In optional implementations, multiple boards may share one or more processors, or multiple boards may share one or more memories, or multiple boards may share one or more processors simultaneously.

[0252] For example, the sending module 43 is configured to perform the functions of an access network device (eg, a target access network device or a source access network device) in any one of the embodiments in FIGS. 3A to 3E.

[0253] An embodiment of the present application further provides a communication device comprising a processor, the processor coupled to a memory, the memory storing a computer program, the processor configured to invoke the computer program in the memory, such that the communication device performs the method according to any one of the embodiments in Figures 3A to 3E.

[0254] An embodiment of the present application further provides a communication device including a processor and an interface circuit, the interface circuit configured to receive a signal from another communication device other than the communication device, transmit the signal to the processor, or transmit a signal from the processor to another communication device other than the communication device, the processor implementing the method according to any one of the embodiments in Figures 3A to 3E by using logic circuits or by executing code instructions.

[0255] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program or instructions, which, when executed by a computer, implements the method according to any one of the embodiments in Figures 3A to 3E.

[0256] An embodiment of the present application further provides a computer program product, which, when read and executed by a computer, enables the computer to perform the method according to any one of the embodiments of Figures 3A to 3E.

[0257] The above units described as separate parts may or may not be physically separate. Parts displayed as units may or may not be physical units, and may be located in one location or distributed over multiple network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions in the embodiments of the present application. In addition, the network element units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The integrated unit may be implemented in the form of hardware or in the form of a software network element unit.

[0258] When implemented in the form of a software network element unit and sold or used as an independent product, the integrated unit may be stored in a computer-readable storage medium. Based on this understanding, an essential contributing part of the technical solution of the present application, or all or part of the technical solution, may be incorporated in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for instructing a computer device (which may be a personal computer, a terminal device, a cloud server, a network device, or the like) to execute all or part of the steps of the method in the embodiments of the present application. The storage medium includes any medium capable of storing program code, such as a USB flash drive, a removable hard disk drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. The above description is merely a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications or replacements that a person skilled in the art can easily conceive within the technical scope disclosed in the present application shall fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims. 。 [Other possible items] [Item 1] 1. A communication method comprising: receiving, by a first access network device, a first message transmitted by a second access network device, wherein the first message includes a first candidate information list and / or a second candidate information list, the first candidate information list including information about one or more candidate relay terminals, the one or more candidate relay terminals being located in one or more cells served by the first access network device, and the second candidate information list including information about one or more candidate cells served by the first access network device; determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, wherein the first configuration information is for the terminal device to communicate with the first access network device through a first target relay terminal, the first target relay terminal being one of the one or more candidate relay terminals; or the first configuration information is for the terminal device to communicate with the first access network device in a first target cell, the first target cell being a cell in the one or more candidate cells; and transmitting, by the first access network device, the first configuration information to the second access network device; A method for providing the above. [Item 2] Before the step of determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: determining, by the first access network device, the first target relay terminal based on the first candidate information list, wherein a serving cell of the first target relay terminal is one of the one or more cells; The method of item 1, comprising: [Item 3] Before the step of determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: determining, by the first access network device, the first target cell based on the second candidate information list; The method of item 1, comprising: [Item 4] The first message further includes a first identifier; The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device. 4. The method according to any one of items 1 to 3. [Item 5] Item 5. The method of item 4, wherein the first access network device ignores the cell indicated by the first identifier if the first identifier includes at least one of: the identifier predefined in the protocol, the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the random value determined by the second access network device. [Item 6] 5. The method of claim 4, wherein when the first access network device obtains the first candidate information list and / or the second candidate information list, the first access network device ignores the cell indicated by the first identifier. [Item 7] When the first identifier is the identifier of the cell recommended by the second access network device to the first access network device, the step of determining, by the first access network device, the first target relay terminal based on the first candidate information list includes: determining, by the first access network device, the first target relay terminal based on the first candidate information list and a cell indicated by the first identifier; Item 5. The method according to item 4, comprising: [Item 8] If the first identifier is the identifier of the cell recommended by the second access network device to the first access network device, the step of determining, by the first access network device, the first target cell based on the second candidate information list includes: determining, by the first access network device, the first target cell based on the second candidate information list and a cell indicated by the first identifier; Item 5. The method according to item 4, comprising: [Item 9] the first message further includes first indication information; the first indication information indicates that the first identifier is the identifier predefined in the protocol; or the first indication information indicates that the first identifier is the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is the identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is the identifier of the cell recommended by the second access network device to the first access network device; or the first indication information indicates that the first identifier is the random value determined by the second access network device; The method according to item 4. [Item 10] 10. The method according to any one of items 4 to 9, wherein the first message is a handover request message, and the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the identifier of the cell recommended by the second access network device to the first access network device is a target cell global identifier. [Item 11] 1. A communication method comprising: receiving, by a second access network device, information about one or more candidate relay terminals reported by a terminal device and / or information about one or more candidate cells reported by said terminal device; determining, by the second access network device, a first candidate information list and / or a second candidate information list based on the information about the one or more candidate relay terminals reported by the terminal device and / or the information about the one or more candidate cells reported by the terminal device, wherein the first candidate information list includes information about one or more candidate relay terminals located in one or more cells served by the first access network device, and the second candidate information list includes information about one or more candidate cells served by the first access network device; sending, by the second access network device, a first message to the first access network device, wherein the first message includes the first candidate information list and / or the second candidate information list; receiving, by the second access network device, first configuration information sent by the first access network device, wherein the first configuration information is for the terminal device to communicate with the first access network device through a first target relay terminal, the first target relay terminal being one of the plurality of candidate relay terminals; or the first configuration information is for the terminal device to communicate with the first access network device in a first target cell, the first target cell being a cell in the one or more candidate cells; and transmitting, by the second access network device, the first configuration information to the terminal device; A method for providing the above. [Item 12] The first message further includes a first identifier; The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device. Item 12. The method according to item 11. [Item 13] the first message further includes first indication information; the first indication information indicates that the first identifier is the identifier predefined in the protocol; or the first indication information indicates that the first identifier is the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is the identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is the identifier of the cell recommended by the second access network device to the first access network device; or the first indication information indicates that the first identifier is the random value determined by the second access network device; Item 13. The method according to item 12. [Item 14] 14. The method according to any one of items 11 to 13, wherein the first message is a handover request message, and the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the identifier of the cell recommended by the second access network device to the first access network device is a target cell global identifier. [Item 15] 1. A communication method comprising: reporting, by the terminal device, information about the one or more candidate relay terminals and / or information about the one or more candidate cells to a second access network device; receiving, by the terminal device, first configuration information sent by the second access network device; and communicating, by the terminal device, with a first access network device through a first target relay terminal based on the first configuration information, or communicating, by the terminal device, with the first access network device in a first target cell based on the first configuration information, the first configuration information is determined by the first access network device based on a first message sent by the second access network device, the first message including a first candidate information list and / or a second candidate information list, the first candidate information list being determined by the second access network device based on the information about the one or more candidate relay terminals reported by the terminal device, and the second candidate information list being determined by the second access network device based on the information about the one or more candidate cells reported by the terminal device; the first candidate information list includes information about one or more candidate relay terminals, the one or more candidate relay terminals being located in one or more cells served by the first access network device, and the first target relay terminal being one of the plurality of candidate relay terminals; and the second candidate information list includes information about one or more candidate cells served by the first access network device, and the first target cell is a cell among the one or more candidate cells; A method for providing the above. [Item 16] The first message further includes a first identifier; The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device. Item 15. The method according to item 15. [Item 17] the first message further includes first indication information; the first indication information indicates that the first identifier is the identifier predefined in the protocol; or the first indication information indicates that the first identifier is the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is the identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is the identifier of the cell recommended by the second access network device to the first access network device; or the first indication information indicates that the first identifier is the random value determined by the second access network device; Item 17. The method according to item 16. [Item 18] 18. The method according to any one of items 15 to 17, wherein the first message is a handover request message, and the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the identifier of the cell recommended by the second access network device to the first access network device is a target cell global identifier. [Item 19] 1. A communication method comprising: receiving, by a second access network device, information about one or more candidate relay terminals reported by a terminal device and / or information about one or more candidate cells reported by said terminal device; determining, by the second access network device, a first candidate information list and / or a second candidate information list based on the information about the one or more candidate relay terminals reported by the terminal device and / or the information about the one or more candidate cells reported by the terminal device, wherein the first candidate information list includes information about one or more candidate relay terminals located in one or more cells served by the first access network device, and the second candidate information list includes information about one or more candidate cells served by the first access network device; sending, by the second access network device, a first message to the first access network device, wherein the first message includes the first candidate information list and / or the second candidate information list; determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, wherein the first configuration information is for the terminal device to communicate with the first access network device through a first target relay terminal, and the first target relay terminal is one of the plurality of candidate relay terminals; or the first configuration information is for the terminal device to communicate with the first access network device in a first target cell, and the first target cell is a cell in the one or more candidate cells; transmitting, by the first access network device, the first configuration information to the second access network device; and transmitting, by the second access network device, the first configuration information to the terminal device; A method for providing the above. [Item 20] Before the step of determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: determining, by the first access network device, the first target relay terminal based on the first candidate information list; 20. The method of claim 19, comprising: [Item 21] Before the step of determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: determining, by the first access network device, the first target cell based on the second candidate information list; 20. The method of claim 19, comprising: [Item 22] The first message further includes a first identifier; The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device. 22. The method according to any one of items 19 to 21. [Item 23] When the first identifier is the identifier of the cell recommended by the second access network device to the first access network device, the step of determining, by the first access network device, the first target relay terminal based on the first candidate information list includes: determining, by the first access network device, the first target relay terminal based on the first candidate information list and a cell indicated by the first identifier; Item 23. The method according to Item 22, comprising: [Item 24] If the first identifier is the identifier of the cell recommended by the second access network device to the first access network device, the step of determining, by the first access network device, the first target cell based on the second candidate information list includes: determining, by the first access network device, the first target cell based on the second candidate information list and a cell indicated by the first identifier; Item 23. The method according to Item 22, comprising: [Item 25] 25. The method of any one of items 22 to 24, wherein the first message is a handover request message, and the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the identifier of the cell recommended by the second access network device to the first access network device is a target cell global identifier. [Item 26] 26. A communication device comprising a module configured to perform the method according to any one of items 1 to 25. [Item 27] 26. A communication device comprising a processor, wherein the processor is coupled to a memory, the memory storing a computer program; and the processor is configured to invoke the computer program in the memory, such that the communication device performs the method of any one of items 1 to 25. [Item 28] 26. A communication device comprising a processor and an interface circuit, wherein the interface circuit is configured to: receive a signal from another communication device other than the communication device and transmit the signal to the processor, or to transmit a signal from the processor to another communication device other than the communication device; and wherein the processor is configured to implement the method of any one of items 1 to 25 by using logic circuits or by executing code instructions. [Item 29] 26. A computer-readable storage medium storing a computer program or instructions, which, when executed by a computer, implements the method of any one of items 1 to 25. [Item 30] 26. A computer program product, which when read and executed by a computer, enables the computer to carry out the method according to any one of items 1 to 25.

Claims

1. 1. A communication method comprising: receiving, by a first access network device, a first message transmitted by a second access network device, wherein the first message includes a first candidate information list and / or a second candidate information list, the first candidate information list including information about one or more candidate relay terminals, the one or more candidate relay terminals being located in one or more cells served by the first access network device, and the second candidate information list including information about one or more candidate cells served by the first access network device; determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, wherein the first configuration information is for the terminal device to communicate with the first access network device through a first target relay terminal, the first target relay terminal being one of the one or more candidate relay terminals; or the first configuration information is for the terminal device to communicate with the first access network device in a first target cell, the first target cell being a cell in the one or more candidate cells; and transmitting, by the first access network device, the first configuration information to the second access network device; A method for providing the above.

2. Before the step of determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: determining, by the first access network device, the first target relay terminal based on the first candidate information list, wherein a serving cell of the first target relay terminal is one of the one or more cells; The method of claim 1 , comprising:

3. Before the step of determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: determining, by the first access network device, the first target cell based on the second candidate information list; The method of claim 1 , comprising:

4. The first message further includes a first identifier; The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device.

4. The method according to any one of claims 1 to 3.

5. 5. The method of claim 4, wherein the first access network device ignores the cell indicated by the first identifier if the first identifier includes at least one of: the identifier predefined in the protocol, the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the random value determined by the second access network device.

6. 5. The method of claim 4, wherein when the first access network device obtains the first candidate information list and / or the second candidate information list, the first access network device ignores the cell indicated by the first identifier.

7. When the first identifier is the identifier of the cell recommended by the second access network device to the first access network device, the step of determining, by the first access network device, the first target relay terminal based on the first candidate information list: determining, by the first access network device, the first target relay terminal based on the first candidate information list and a cell indicated by the first identifier; The method of claim 4, comprising:

8. If the first identifier is the identifier of the cell recommended by the second access network device to the first access network device, the step of determining, by the first access network device, the first target cell based on the second candidate information list: determining, by the first access network device, the first target cell based on the second candidate information list and a cell indicated by the first identifier; The method of claim 4, comprising:

9. the first message further includes first indication information; the first indication information indicates that the first identifier is a predefined identifier in the protocol; or the first indication information indicates that the first identifier is the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is the identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is the identifier of the cell recommended by the second access network device to the first access network device; or the first indication information indicates that the first identifier is the random value determined by the second access network device. The method of claim 4.

10. 10. The method of claim 4, wherein the first message is a handover request message, and the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the identifier of the cell recommended by the second access network device to the first access network device is a target cell global identifier.

11. 1. A communication method comprising: receiving, by a second access network device, information about one or more candidate relay terminals reported by a terminal device and / or information about one or more candidate cells reported by said terminal device; determining, by the second access network device, a first candidate information list and / or a second candidate information list based on the information about the one or more candidate relay terminals reported by the terminal device and / or the information about the one or more candidate cells reported by the terminal device, wherein the first candidate information list includes information about one or more candidate relay terminals located in one or more cells served by the first access network device, and the second candidate information list includes information about one or more candidate cells served by the first access network device; sending, by the second access network device, a first message to the first access network device, wherein the first message includes the first candidate information list and / or the second candidate information list; receiving, by the second access network device, first configuration information sent by the first access network device, wherein the first configuration information is for the terminal device to communicate with the first access network device through a first target relay terminal, the first target relay terminal being one of the plurality of candidate relay terminals; or the first configuration information is for the terminal device to communicate with the first access network device in a first target cell, the first target cell being a cell in the one or more candidate cells; and transmitting, by the second access network device, the first configuration information to the terminal device. A method for providing the above.

12. The first message further includes a first identifier; The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device. The method of claim 11.

13. the first message further includes first indication information; the first indication information indicates that the first identifier is a predefined identifier in the protocol; or the first indication information indicates that the first identifier is the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is the identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is the identifier of the cell recommended by the second access network device to the first access network device; or the first indication information indicates that the first identifier is the random value determined by the second access network device. The method of claim 12.

14. 14. The method of claim 11, wherein the first message is a handover request message, and the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the identifier of the cell recommended by the second access network device to the first access network device is a target cell global identifier.

15. 1. A communication method comprising: reporting, by the terminal device, information about one or more candidate relay terminals and / or information about one or more candidate cells to a second access network device; receiving, by the terminal device, first configuration information sent by the second access network device; and communicating, by the terminal device, with a first access network device through a first target relay terminal based on the first configuration information, or communicating, by the terminal device, with the first access network device in a first target cell based on the first configuration information, the first configuration information is determined by the first access network device based on a first message sent by the second access network device, the first message including a first candidate information list and / or a second candidate information list, the first candidate information list being determined by the second access network device based on the information about the one or more candidate relay terminals reported by the terminal device, and the second candidate information list being determined by the second access network device based on the information about the one or more candidate cells reported by the terminal device; the first candidate information list includes information about one or more candidate relay terminals, the one or more candidate relay terminals being located in one or more cells served by the first access network device, and the first target relay terminal being one of the plurality of candidate relay terminals; and the second candidate information list includes information about one or more candidate cells served by the first access network device, and the first target cell is a cell among the one or more candidate cells; A method for providing the above.

16. The first message further includes a first identifier; The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device.

16. The method of claim 15.

17. the first message further includes first indication information; the first indication information indicates that the first identifier is a predefined identifier in the protocol; or the first indication information indicates that the first identifier is the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located; or the first indication information indicates that the first identifier is the identifier of any candidate cell reported by the terminal device; or the first indication information indicates that the first identifier is the identifier of the cell recommended by the second access network device to the first access network device; or the first indication information indicates that the first identifier is the random value determined by the second access network device.

17. The method of claim 16.

18. 18. The method of claim 15, wherein the first message is a handover request message, and the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the identifier of the cell recommended by the second access network device to the first access network device is a target cell global identifier.

19. 1. A communication method comprising: receiving, by a second access network device, information about one or more candidate relay terminals reported by a terminal device and / or information about one or more candidate cells reported by said terminal device; determining, by the second access network device, a first candidate information list and / or a second candidate information list based on the information about the one or more candidate relay terminals reported by the terminal device and / or the information about the one or more candidate cells reported by the terminal device, wherein the first candidate information list includes information about one or more candidate relay terminals located in one or more cells served by the first access network device, and the second candidate information list includes information about one or more candidate cells served by the first access network device; sending, by the second access network device, a first message to the first access network device, wherein the first message includes the first candidate information list and / or the second candidate information list; determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, wherein the first configuration information is for the terminal device to communicate with the first access network device through a first target relay terminal, and the first target relay terminal is one of the plurality of candidate relay terminals; or the first configuration information is for the terminal device to communicate with the first access network device in a first target cell, and the first target cell is a cell in the one or more candidate cells; transmitting, by the first access network device, the first configuration information to the second access network device; and transmitting, by the second access network device, the first configuration information to the terminal device. A method for providing the above.

20. Before the step of determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: determining, by the first access network device, the first target relay terminal based on the first candidate information list; 20. The method of claim 19, comprising:

21. Before the step of determining, by the first access network device, first configuration information based on the first candidate information list and / or the second candidate information list, the method further comprises: determining, by the first access network device, the first target cell based on the second candidate information list; 20. The method of claim 19, comprising:

22. The first message further includes a first identifier; The first identifier includes at least one of: an identifier predefined in a protocol, an identifier of a cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, an identifier of any candidate cell reported by the terminal device, an identifier of a cell recommended by the second access network device to the first access network device, or a random value determined by the second access network device.

22. The method of any one of claims 19 to 21.

23. When the first identifier is the identifier of the cell recommended by the second access network device to the first access network device, the step of determining, by the first access network device, the first target relay terminal based on the first candidate information list: determining, by the first access network device, the first target relay terminal based on the first candidate information list and a cell indicated by the first identifier; 23. The method of claim 22, comprising:

24. If the first identifier is the identifier of the cell recommended by the second access network device to the first access network device, the step of determining, by the first access network device, the first target cell based on the second candidate information list: determining, by the first access network device, the first target cell based on the second candidate information list and a cell indicated by the first identifier; 23. The method of claim 22, comprising:

25. 25. The method of claim 22, wherein the first message is a handover request message, and the identifier of the cell in which any one of the one or more candidate relay terminals reported by the terminal device is located, the identifier of any candidate cell reported by the terminal device, or the identifier of the cell recommended by the second access network device to the first access network device is a target cell global identifier.

26. A communication device comprising modules adapted to carry out the method of any one of claims 1 to 25.

27. 26. A communications device comprising a processor, wherein the processor is coupled to a memory, the memory storing a computer program; and the processor is configured to invoke the computer program in the memory, such that the communications device performs the method of any one of claims 1 to 25.

28. 26. A communication device comprising a processor and an interface circuit, wherein the interface circuit is configured to: receive signals from another communication device other than the communication device and transmit the signals to the processor, or to transmit signals from the processor to another communication device other than the communication device; and wherein the processor is configured to implement a method according to any one of claims 1 to 25 by using logic circuits or by executing code instructions.

29. 26. A computer readable storage medium storing a computer program or instructions which, when executed by a computer, implements the method of any one of claims 1 to 25.

30. A computer program product, which when read and executed by a computer enables the computer to carry out the method of any one of claims 1 to 25.

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