A communication method and apparatus

Abstract

The application provides a communication method and device. The method comprises the following steps: a first terminal device and / or a second terminal device sends first information to a first network device, and receives second information from the first network device, wherein the first information is used for the first network device to determine that the first terminal device and the second terminal device are switched from the first network device to a second network device in the form of a cooperative group, and the second information indicates that the first terminal device and the second terminal device are switched from the first network device to the second network device in the form of the cooperative group. The first network device can effectively determine that the first terminal device and the second terminal device are switched from the first network device to the second network device in the form of the cooperative group according to the first information, the whole switching from the first network device to the second network device can be realized, the cooperative relationship between the first terminal device and the second terminal device can be maintained, and the cooperative relationship does not need to be released and re-established before and after the switching, which helps to effectively reduce the signaling overhead.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0002] Satellite communication, as a typical scenario of non-terrestrial networks (NTNs), features long communication distances, large coverage areas, and flexible networking. It can provide services to both fixed and various mobile terminal devices. When satellite communication is introduced into traditional communication systems (such as 5G systems), with base stations or parts of their functions deployed on satellites, it not only provides seamless coverage for terminal devices but also avoids the impact of natural disasters and ensures the reliability of the communication system.

[0003] In satellite communication scenarios, considering the long distance between the satellite and the ground, to ensure service continuity, when the communication quality of the remote terminal is poor, a suitable relay terminal can be selected to assist the remote terminal in communicating with the satellite. Furthermore, due to the mobile nature of satellites, the service time provided by a satellite to terminal equipment in a certain ground area is limited and cannot be extended. In such cases, the terminal equipment in that ground area needs to perform frequent satellite handovers, and since the relay terminal is closer to the remote terminal, they usually need to handover together.

[0004] However, existing protocols do not support cross-satellite (or cross-site) handovers between the same relay terminal and remote terminal while maintaining their cooperative relationship. If it is desired that the remote terminal continues to communicate with the target satellite through the same relay terminal after the handover, a cross-satellite handover is required first, from a non-direct path (i.e., the path through which the remote terminal communicates with the source satellite via the relay terminal) to a direct path (i.e., the path through which the remote terminal directly communicates with the target satellite), while the relay terminal also performs a cross-satellite handover. Then, a same-satellite (or same-site) handover is performed, from the direct path to a non-direct path (i.e., the path through which the remote terminal communicates with the target satellite via the relay terminal). Alternatively, the sidelink connection between the relay terminal and the remote terminal can be released first, and both the relay terminal and the remote terminal can perform cross-satellite handovers separately. After each cross-satellite handover is completed, the sidelink connection between the relay terminal and the remote terminal can be re-established. However, these handover methods incur significant signaling overhead. Further research is needed to effectively reduce this signaling overhead. Summary of the Invention

[0005] This application provides a communication method and apparatus for effectively reducing signaling overhead.

[0006] Firstly, this application provides a communication method that can be executed by a first terminal device and / or a second terminal device. For example, the terminal device can be a terminal equipment, or a component within the terminal equipment, such as a communication module, circuits or chips responsible for communication functions (e.g., modem chips, also known as baseband chips, or system-on-chip (SoC) chips containing modem cores or system-in-package (SIP) chips), chip systems, or processors, etc. It can also be a logic module or software capable of implementing all or part of the terminal equipment's functions. The method may include the following steps: a first terminal device and / or a second terminal device send first information to a first network device, and then the first terminal device and / or the second terminal device receive second information from the first network device, wherein the first information is used by the first network device to determine that the first terminal device and the second terminal device switch from the first network device to the second network device in the form of a cooperative group, the switch from the first network device to the second network device in the form of a cooperative group indicates that before the switch, the first terminal device communicated with the first network device through the second terminal device, and after the switch, the first terminal device communicates with the second network device through the second terminal device, and the second information is used to instruct the first terminal device and the second terminal device to switch from the first network device to the second network device in the form of a cooperative group.

[0007] In this method, by sending first information to the first network device, the first network device can determine in a timely and effective manner whether the first terminal device and the second terminal device are switching from the first network device to the second network device in the form of a cooperative group. This helps the first terminal device and the second terminal device to switch from the first network device to the second network device together as a whole. This allows the cooperative relationship between the first terminal device and the second terminal device to be maintained while switching from the first network device to the second network device as a whole, without having to release and re-establish the cooperative relationship between the first terminal device and the second terminal device before and after the switch. This helps to effectively reduce (or save) signaling overhead and reduce handover latency.

[0008] In one possible implementation, before the first terminal device and / or the second terminal device send the first information to the first network device, the method further includes:

[0009] The first terminal device and / or the second terminal device determine that the switching mode of the first terminal device and the second terminal device is a cooperative group switching mode, wherein the cooperative group switching mode means that the first terminal device and the second terminal device switch from the first network device to the target network device in the form of a cooperative group, and the target network device may include the second network device.

[0010] In the above implementation, by pre-determining the switching mode of the first terminal device and / or the second terminal device as the cooperative group switching mode, the first terminal device and / or the second terminal device can report only part of the measurement results to the first network device. This also enables the first network device to accurately determine whether to switch the first terminal device and the second terminal device to the second network device in the form of a cooperative group. This helps to reduce the number of measurement results reported, thereby saving measurement reporting costs.

[0011] In one possible implementation, the first terminal device and / or the second terminal device determine that the handover mode of the first terminal device and the second terminal device is a cooperative group handover mode, including:

[0012] The first terminal device and / or the second terminal device receive third information from the first network device, wherein the third information is used to indicate that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode. Then, the first terminal device and / or the second terminal device determine that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode according to the third information.

[0013] In the above implementation, the first network device can determine in advance that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, and can send the cooperative group switching mode to the first terminal device and / or the second terminal device in advance, without the first terminal device and / or the second terminal device needing to determine that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode. This helps to reduce the computational consumption (such as resource consumption, power consumption, etc.) of the first terminal device and / or the second terminal device, and makes it easier for the first terminal device and / or the second terminal device to determine in a timely manner that only part of the measurement results need to be reported to the first network device. This allows the first network device to accurately determine whether to switch the first terminal device and the second terminal device from the first network device to the second network device in the form of a cooperative group, which helps to reduce the number of measurement results reported, thereby saving measurement reporting overhead.

[0014] In one possible implementation, the first terminal device and / or the second terminal device determine that the handover mode of the first terminal device and the second terminal device is a cooperative group handover mode, provided that at least one of the following conditions is met:

[0015] The side link signal quality between the first terminal device and the second terminal device is greater than or equal to the first threshold.

[0016] The distance between the first terminal device and the second terminal device is less than or equal to a distance threshold, wherein the distance is determined based on the first location information of the first terminal device and the second location information of the second terminal device.

[0017] The path loss between the first terminal device and the second terminal device is less than or equal to the loss threshold.

[0018] The identifier of the first serving cell of the first terminal device is the same as the identifier of the second serving cell of the second terminal device;

[0019] The identifier of the first service beam of the first terminal device is the same as the identifier of the second service beam of the second terminal device.

[0020] The matching degree between the first visible information of the first terminal device to the first network device and the second visible information of the second terminal device to the first network device is greater than or equal to the second threshold.

[0021] The matching degree between the third visible information of the first terminal device to the second network device and the fourth visible information of the second terminal device to the second network device is greater than or equal to the third threshold.

[0022] The distance between the movement trajectory of the first terminal device and the movement trajectory of the second terminal device is less than or equal to a fourth threshold, wherein the movement trajectory of the first terminal device is determined based on the first movement trajectory information of the first terminal device, and the movement trajectory of the second terminal device is determined based on the second movement trajectory information of the second terminal device; or,

[0023] The difference between the attitude angle of the first terminal device and the attitude angle of the second terminal device is less than or equal to a fifth threshold, wherein the attitude angle of the first terminal device is determined based on the first attitude information of the first terminal device, and the attitude angle of the second terminal device is determined based on the second attitude information of the second terminal device.

[0024] In the above implementation, the first terminal device and / or the second terminal device can determine (or self-determine) the switching mode of the first terminal device and the second terminal device as the cooperative group switching mode, without the first network device instructing the first terminal device and the second terminal device to switch to the cooperative group switching mode. Therefore, signaling overhead can be saved, and the first terminal device and / or the second terminal device can actively determine the switching mode of the first terminal device and the second terminal device.

[0025] In one possible implementation, the method further includes:

[0026] The first terminal device and / or the second terminal device send fourth information to the first network device, wherein the fourth information is used by the first network device to determine that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode.

[0027] The above implementation method enables the first network device to determine in a timely and accurate manner whether the switching mode of the first terminal device and the second terminal device is a cooperative group switching mode based on the fourth information from the first terminal device and / or the second terminal device.

[0028] In one possible implementation, the fourth information may include at least one of the following:

[0029] The switching mode between the first terminal device and the second terminal device is the cooperative group switching mode.

[0030] The side link signal quality between the first terminal device and the second terminal device;

[0031] First location information of the first terminal device;

[0032] Second location information of the second terminal location;

[0033] Path loss between the first terminal device and the second terminal device;

[0034] The identifier of the first serving cell of the first terminal device;

[0035] The identifier of the first serving beam of the first terminal device;

[0036] The identifier of the second serving cell of the second terminal device;

[0037] The identifier of the second service beam of the second terminal device;

[0038] First visible information of the first terminal device to the first network device;

[0039] The second visible information of the second terminal device to the first network device;

[0040] The third visible information of the first terminal device to the second network device;

[0041] The fourth visible information of the second terminal device to the second network device;

[0042] First movement trajectory information of the first terminal device;

[0043] The second movement trajectory information of the second terminal device;

[0044] The first posture information of the first terminal device; or...

[0045] The second attitude information of the second terminal device.

[0046] In the above implementation, at least one piece of information included in the fourth information can be used by the first network device to determine in a timely and accurate manner whether the switching mode of the first terminal device and the second terminal device is a cooperative group switching mode, thereby making the judgment of the cooperative group switching mode more accurate.

[0047] In one possible implementation, the first information may include at least one of the following: first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality, or sixth signal quality;

[0048] The first signal quality is obtained by the first terminal device measuring the signal of the first network device; the second signal quality is obtained by the first terminal device measuring the signal of the second network device; the third signal quality is obtained by the second terminal device measuring the signal of the first network device; the fourth signal quality is obtained by the second terminal device measuring the signal of the second network device; the fifth signal quality represents the sidelink signal quality between the first terminal device and the second terminal device; and the sixth signal quality represents the sidelink signal quality between the first terminal device and the third terminal device. The second terminal device and the third terminal device are included in a plurality of candidate terminal devices for providing relay services.

[0049] In the above implementation, the first information includes at least one signal quality, which can help the first network device to determine in a timely and accurate manner whether the first terminal device and the second terminal device are switching from the first network device to the second network device in the form of a cooperative group. This makes the overall switching judgment of the first terminal device and the second terminal device more accurate and more in line with the actual situation.

[0050] In one possible implementation, the first terminal device and / or the second terminal device send the first information to the first network device if at least one of the following conditions is met:

[0051] The difference between the fourth signal quality and the third signal quality is greater than or equal to the sixth threshold;

[0052] The difference between the fourth signal quality and the maximum signal quality among the first and second signal qualities is greater than or equal to the seventh threshold.

[0053] The quality of the fifth signal is greater than or equal to the eighth threshold;

[0054] The difference between the quality of the fifth signal and the quality of the sixth signal is greater than or equal to the ninth threshold;

[0055] The difference between the fourth signal quality and the first signal quality is greater than or equal to the tenth threshold.

[0056] The difference between the quality of the fourth signal and the quality of the second signal is greater than or equal to the eleventh threshold; or,

[0057] The difference between the second signal quality and the first signal quality is greater than or equal to the twelfth threshold.

[0058] The above implementation method allows the first terminal device and / or the second terminal device to report the measurement results to the first network device only when at least one of the above conditions is met, without having to periodically report the measurement results to the first network device. Therefore, it can effectively reduce the number of times the measurement results are reported and help save signaling overhead.

[0059] In one possible implementation, when the first terminal device receives the second information, the second information may include at least one of the following: relay configuration information, end-to-end radio bearer information, or access configuration information;

[0060] The relay configuration information may include at least one of the following: the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, or PC5 relay radio link control (RLC) channel configuration information.

[0061] The access configuration information may include at least one of the following: the cell identifier of the second network device, or access information used by the first terminal device to access the second network device.

[0062] In the above implementation, the second information for the first terminal device can be used by the first terminal device to effectively perform cross-network device switching.

[0063] In one possible implementation, when the second terminal device receives the second information, the second information may include at least one of the following: relay configuration information, bearer mapping configuration information, or access configuration information;

[0064] The relay configuration information may include at least one of the following: the local identifier of the second terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, PC5 relay RLC channel configuration information, or air interface relay RLC channel configuration information.

[0065] The access configuration information may include at least one of the following: the cell identifier of the second network device, or access information for the second terminal device to access the second network device.

[0066] In the above implementation, the second information for the second terminal device can be used to effectively switch between network devices.

[0067] Secondly, this application provides a communication method that can be executed by a first network device. The first network device can be a network device, or a component within a network device, such as a communication module, processor, chip, chip system, or circuit that can be applied in a first access network device. It can also be a logic module or software that can implement all or part of the functions of the first access network device. The method may include the following steps: a first network device receives first information from a first terminal device and / or a second terminal device, wherein the first information is used to determine that the first terminal device and the second terminal device are switching from the first network device to the second network device in the form of a cooperative group. Switching from the first network device to the second network device in the form of a cooperative group indicates that before the switch, the first terminal device communicated with the first network device through the second terminal device, and after the switch, the first terminal device communicates with the second network device through the second terminal device. Next, the first network device may send fifth information to the second network device, wherein the fifth information is used to request that the first terminal device and the second terminal device be switched from the first network device to the second network device in the form of a cooperative group. After that, the first network device may receive sixth information from the second network device, wherein the sixth information includes configuration information required for the first terminal device to communicate under the second network device and configuration information required for the second terminal device to communicate under the second network device. Then, the first network device may send second information to the first terminal device and / or the second terminal device, wherein the second information is used to instruct the first terminal device and the second terminal device to switch from the first network device to the second network device in the form of a cooperative group.

[0068] The technical effects achievable in the second aspect are similar to those achievable in the first aspect, and will not be elaborated upon here.

[0069] In one possible implementation, the method further includes:

[0070] The first network device receives fourth information from the first terminal device and / or the second terminal device, wherein the fourth information is used to determine that the switching mode of the first terminal device and the second terminal device is a cooperative group switching mode. The cooperative group switching mode indicates that the first terminal device and the second terminal device switch from the first network device to the target network device in the form of a cooperative group. The target network device may include the second network device.

[0071] For the technical effects that can be achieved by the above implementation method, please refer to the technical effects that can be achieved by the corresponding implementation method provided in the first aspect above, which will not be repeated here.

[0072] In one possible implementation, the fourth information may include at least one of the following:

[0073] The switching mode between the first terminal device and the second terminal device is the cooperative group switching mode.

[0074] The side link signal quality between the first terminal device and the second terminal device;

[0075] First location information of the first terminal device;

[0076] Second location information of the second terminal location;

[0077] Path loss between the first terminal device and the second terminal device;

[0078] The identifier of the first serving cell of the first terminal device;

[0079] The identifier of the first serving beam of the first terminal device;

[0080] The identifier of the second serving cell of the second terminal device;

[0081] The identifier of the second service beam of the second terminal device;

[0082] First visible information of the first terminal device to the first network device;

[0083] The second visible information of the second terminal device to the first network device;

[0084] The third visible information of the first terminal device to the second network device;

[0085] The fourth visible information of the second terminal device to the second network device;

[0086] First movement trajectory information of the first terminal device;

[0087] The second movement trajectory information of the second terminal device;

[0088] The first posture information of the first terminal device; or...

[0089] The second attitude information of the second terminal device.

[0090] For the technical effects that can be achieved by the above implementation method, please refer to the technical effects that can be achieved by the corresponding implementation method provided in the first aspect above, which will not be repeated here.

[0091] In one possible implementation, the method further includes:

[0092] If the fourth information includes that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, then the first network device can determine that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode based on the fourth information.

[0093] The above implementation method enables the first network device to directly determine the switching mode of the first terminal device and the second terminal device as the cooperative group switching mode based on the cooperative group switching mode included in the fourth information, without the first network device needing to recalculate and determine it. Therefore, it can save the computational consumption (such as resource consumption, power consumption, etc.) of the first network device.

[0094] In one possible implementation, the method further includes:

[0095] The first network device determines that the handover mode of the first terminal device and the second terminal device is the cooperative group handover mode if at least one of the following conditions is met:

[0096] The side link signal quality between the first terminal device and the second terminal device is greater than or equal to the first threshold.

[0097] The distance between the first terminal device and the second terminal device is less than or equal to a distance threshold, wherein the distance is determined based on the first location information of the first terminal device and the second location information of the second terminal device.

[0098] The path loss between the first terminal device and the second terminal device is less than or equal to the loss threshold.

[0099] The identifier of the first serving cell of the first terminal device is the same as the identifier of the second serving cell of the second terminal device;

[0100] The identifier of the first service beam of the first terminal device is the same as the identifier of the second service beam of the second terminal device.

[0101] The matching degree between the first visible information of the first terminal device to the first network device and the second visible information of the second terminal device to the first network device is greater than or equal to the second threshold.

[0102] The matching degree between the third visible information of the first terminal device to the second network device and the fourth visible information of the second terminal device to the second network device is greater than or equal to the third threshold.

[0103] The distance between the movement trajectory of the first terminal device and the movement trajectory of the second terminal device is less than or equal to a fourth threshold, wherein the movement trajectory of the first terminal device is determined based on the first movement trajectory information of the first terminal device, and the movement trajectory of the second terminal device is determined based on the second movement trajectory information of the second terminal device; or,

[0104] The difference between the attitude angle of the first terminal device and the attitude angle of the second terminal device is less than or equal to a fifth threshold, wherein the attitude angle of the first terminal device is determined based on the first attitude information of the first terminal device, and the attitude angle of the second terminal device is determined based on the second attitude information of the second terminal device.

[0105] In the above implementation, the first network device can determine (or automatically determine) the switching mode of the first terminal device and the second terminal device as the cooperative group switching mode, which helps the first network device to actively determine the switching mode of the first terminal device and the second terminal device. Furthermore, this implementation eliminates the need for the first terminal device or the second terminal device to indicate the cooperative group switching mode in the fourth information, thus saving bit overhead.

[0106] In one possible implementation, the method further includes:

[0107] The first network device sends third information to the first terminal device and / or the second terminal device, wherein the third information is used to indicate that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode.

[0108] For the technical effects that can be achieved by the above implementation method, please refer to the technical effects that can be achieved by the corresponding implementation method provided in the first aspect above, which will not be repeated here.

[0109] In one possible implementation, the method further includes:

[0110] The first network device sends a seventh message to the second network device, wherein the seventh message is used to indicate that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode.

[0111] In the above implementation, by sending the seventh information to the second network device, the second network device can promptly learn that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, and record (or store) this switching mode for subsequent use, without needing to subsequently redetermine the switching mode of the first terminal device and the second terminal device. This helps to save costs (such as computing costs, resource costs, or power costs). Alternatively, this method also eliminates the need for the first terminal device or the second terminal device to subsequently report the switching mode of the first terminal device and the second terminal device to the second network device, which helps to save communication costs.

[0112] In one possible implementation, the first information may include at least one of the following: first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality, or sixth signal quality;

[0113] The first signal quality is obtained by the first terminal device measuring the signal of the first network device; the second signal quality is obtained by the first terminal device measuring the signal of the second network device; the third signal quality is obtained by the second terminal device measuring the signal of the first network device; the fourth signal quality is obtained by the second terminal device measuring the signal of the second network device; the fifth signal quality represents the sidelink signal quality between the first terminal device and the second terminal device; and the sixth signal quality represents the sidelink signal quality between the first terminal device and the third terminal device. The second terminal device and the third terminal device are included in a plurality of candidate terminal devices for providing relay services.

[0114] For the technical effects that can be achieved by the above implementation method, please refer to the technical effects that can be achieved by the corresponding implementation method provided in the first aspect above, which will not be repeated here.

[0115] In one possible implementation, the method further includes:

[0116] The first network device determines that the first terminal device and the second terminal device are switching from the first network device to the second network device in the form of a cooperative group if at least one of the following conditions is met:

[0117] The difference between the fourth signal quality and the third signal quality is greater than or equal to the sixth threshold;

[0118] The difference between the fourth signal quality and the maximum signal quality among the first and second signal qualities is greater than or equal to the seventh threshold.

[0119] The quality of the fifth signal is greater than or equal to the eighth threshold;

[0120] The difference between the quality of the fifth signal and the quality of the sixth signal is greater than or equal to the ninth threshold;

[0121] The difference between the fourth signal quality and the first signal quality is greater than or equal to the tenth threshold.

[0122] The difference between the quality of the fourth signal and the quality of the second signal is greater than or equal to the eleventh threshold; or,

[0123] The difference between the second signal quality and the first signal quality is greater than or equal to the twelfth threshold.

[0124] The above implementation method enables the first network device to determine, based on at least one of the above conditions, that the first terminal device and the second terminal device switch from the first network device to the second network device in the form of a cooperative group, so that the first network device can send the fifth information to the second network device in a timely and effective manner, thereby making the sending of the fifth information more accurate and more reasonable.

[0125] In one possible implementation, when the first network device sends second information to the first terminal device, the second information may include at least one of the following: relay configuration information, end-to-end radio bearer information, or access configuration information;

[0126] The relay configuration information may include at least one of the following: the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, or PC5 relay RLC channel configuration information;

[0127] The access configuration information may include at least one of the following: the cell identifier of the second network device, or access information used by the first terminal device to access the second network device.

[0128] For the technical effects that can be achieved by the above implementation method, please refer to the technical effects that can be achieved by the corresponding implementation method provided in the first aspect above, which will not be repeated here.

[0129] In one possible implementation, when the first network device sends second information to the second terminal device, the second information may include at least one of the following: relay configuration information, bearer mapping configuration information, or access configuration information;

[0130] The relay configuration information may include at least one of the following: the local identifier of the second terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, PC5 relay RLC channel configuration information, or air interface relay RLC channel configuration information.

[0131] The access configuration information may include at least one of the following: the cell identifier of the second network device, or access information for the second terminal device to access the second network device.

[0132] For the technical effects that can be achieved by the above implementation method, please refer to the technical effects that can be achieved by the corresponding implementation method provided in the first aspect above, which will not be repeated here.

[0133] Thirdly, this application provides a communication method that can be executed by a second network device. The second network device can be a network device or a component within a network device, such as a communication module, processor, chip, chip system, or circuit applicable to a second access network device. It can also be a logic module or software capable of implementing all or part of the functions of the second access network device. The method may include the following steps: the second network device receives fifth information from a first network device; subsequently, the second network device may send sixth information to the first network device. The fifth information requests a switch between the first and second terminal devices in a cooperative group from the first network device to the second network device. Switching from the first network device to the second network device in a cooperative group indicates that before the switch, the first terminal device communicated with the first network device through the second terminal device, and after the switch, the first terminal device communicates with the second network device through the second terminal device. The sixth information includes configuration information required for the first terminal device to communicate under the second network device and configuration information required for the second terminal device to communicate under the second network device.

[0134] The technical effects achievable in the third aspect are similar to those achievable in the second aspect above, and will not be elaborated upon here.

[0135] In one possible implementation, the method further includes:

[0136] The second network device receives a seventh message from the first network device, wherein the seventh message is used to indicate that the switching mode of the first terminal device and the second terminal device is a cooperative group switching mode.

[0137] For the technical effects that can be achieved by the above implementation method, please refer to the technical effects that can be achieved by the corresponding implementation method provided in the second aspect above, which will not be repeated here.

[0138] In one possible implementation, the configuration information required for the first terminal device to communicate with the second network device may include at least one of the following: relay configuration information, end-to-end radio bearer information, or access configuration information;

[0139] The relay configuration information may include at least one of the following: the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, or PC5 relay RLC channel configuration information;

[0140] The access configuration information may include at least one of the following: the cell identifier of the second network device, or access information used by the first terminal device to access the second network device.

[0141] For the technical effects that can be achieved by the above implementation method, please refer to the technical effects that can be achieved by the corresponding implementation method provided in the first aspect above, which will not be repeated here.

[0142] In one possible implementation, the configuration information required for the second terminal device to communicate under the second network device may include at least one of the following: relay configuration information, bearer mapping configuration information, or access configuration information;

[0143] The relay configuration information may include at least one of the following: the local identifier of the second terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, PC5 relay RLC channel configuration information, or air interface relay RLC channel configuration information.

[0144] The access configuration information may include at least one of the following: the cell identifier of the second network device, or access information for the second terminal device to access the second network device.

[0145] For the technical effects that can be achieved by the above implementation method, please refer to the technical effects that can be achieved by the corresponding implementation method provided in the first aspect above, which will not be repeated here.

[0146] In one possible implementation provided in the first, second, or third aspect, the first network device or the second network device may be a non-terrestrial network (NTN) device.

[0147] For example, an NTN device can be an NTN equipment or a chip (or chip system, circuit, or unit) within an NTN equipment. For instance, an NTN equipment can be a satellite, drone, or high-altitude platform, or it can be a base station device deployed within a satellite, drone, or high-altitude platform.

[0148] In satellite communication scenarios, NTN devices (such as satellites) may be frequently mobile. This movement necessitates frequent NTN device handovers by ground terminals, resulting in significant signaling overhead. In the aforementioned implementation, the first terminal device and / or the second terminal device send first information to the first NTN device. This facilitates the first NTN device's timely and effective determination of the handover process between the first and second terminal devices as a cooperative group. This allows the first and second terminal devices to handover together as a whole, maintaining their cooperative relationship without needing to release and re-establish this relationship before or after the handover. This effectively reduces the signaling overhead and handover latency in satellite communication scenarios.

[0149] Fourthly, this application provides a communication apparatus, including units or means for performing the various steps of any of the implementation methods in the first aspect described above.

[0150] For example, the communication device can be a first terminal device or a second terminal device. The terminal device can be, for example, a terminal equipment or a module within a terminal equipment (such as a processor, processing unit, chip system, circuit, or chip). The communication device has the function of implementing the method in any of the possible implementations of the first aspect described above. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described function.

[0151] Fifthly, this application provides a communication apparatus, including units or means for performing various steps of any of the implementation methods in the second or third aspects described above.

[0152] For example, the communication device can be a first network device or a second network device. A network device can be, for example, a network equipment or a module within a network equipment (such as a processor, processing unit, chip system, circuit, or chip). The communication device has the functionality to implement the methods in any of the possible implementations of the second or third aspect described above. This functionality can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the aforementioned functionality.

[0153] Sixthly, this application provides a communication device that has the functions involved in the first to third aspects described above. For example, the communication device includes modules, units, or means that perform the operations involved in the first to third aspects described above. The functions, units, or means can be implemented by software, or by hardware, or by hardware executing corresponding software.

[0154] In one possible implementation, the communication device includes a transceiver unit (or communication module, used for sending and receiving data). Optionally, the communication device may further include a processing unit (or processing module), wherein the transceiver unit can be used to send and receive signals to enable communication between the communication device and other devices, for example, the transceiver unit can be used to send data to other communication devices; the processing unit can be used to perform some internal operations of the communication device. The functions performed by the transceiver unit and the processing unit may correspond to the operations involved in the first to third aspects described above.

[0155] In one possible implementation, the communication device includes at least one processor, which can be coupled to a memory. The memory can store necessary computer programs or instructions for implementing the functions described in the first to third aspects above. The processor can execute the computer programs or instructions stored in the memory, causing the communication device to implement the methods in any possible implementation of any of the first to third aspects above when the computer programs or instructions are executed.

[0156] In one possible implementation, the communication device includes at least one processor and a memory, the memory of which can store necessary computer programs or instructions for implementing the functions involved in the first to third aspects described above. The at least one processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible implementation of any of the first to third aspects described above.

[0157] In one possible implementation, the communication device includes at least one processor and an interface circuit (or communication interface), wherein the at least one processor is configured to communicate with other devices via the interface circuit and execute the methods in any of the possible implementations of any of the first to third aspects described above. The interface circuit is used to enable communication between the communication device and other devices, for example, to receive signals from other communication devices and transmit them to the at least one processor, or to send signals from the at least one processor of the communication device to other communication devices, such as the transmission or reception of data and / or signals. Exemplarily, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

[0158] It is understood that, in the sixth aspect mentioned above, the processor can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc.; when implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. Furthermore, there can be one or more processors, and one or more memories. The memory can be integrated with the processor, or the memory and processor can be separately configured. In specific implementations, the memory can be integrated with the processor on the same chip, or it can be configured on different chips. This application does not limit the type of memory or the configuration of the memory and processor.

[0159] Seventhly, this application provides a possible communication system, which may include the first terminal device, second terminal device, first network device, or second network device mentioned in the first, second, or third aspects above. The functional implementation of the first terminal device, second terminal device, first network device, or second network device can be found in the relevant descriptions mentioned in the first, second, or third aspects above, and will not be repeated here.

[0160] For example, the number of the first terminal device, the second terminal device, the first network device, or the second network device can be one or more.

[0161] Eighthly, this application provides a computer program product comprising a computer program or instructions that, when executed on a communication device (or computer), cause the communication device (or computer) to perform the method in any possible implementation of any of the first to third aspects described above.

[0162] Ninthly, this application provides a computer-readable storage medium storing a computer program or instructions that, when executed by a communication device (or computer), cause the communication device (or computer) to perform the method in any possible implementation of any of the first to third aspects described above.

[0163] In a tenth aspect, this application provides a chip that may include at least one processor and may also include a memory (or the chip may be coupled to the memory), the chip executing program instructions in the memory to cause the chip to perform any possible implementation of any of the first to third aspects described above. Here, "coupling" refers to two components being directly or indirectly connected to each other, such as coupling referring to an electrical connection between two components.

[0164] Eleventhly, this application also provides a chip system including at least one processor for supporting a computer device in implementing any possible implementation of the methods in any of the first to third aspects described above. In one possible implementation, the chip system further includes a memory for storing programs and data necessary for the computer device. The chip system may be composed of chips or may include chips and other discrete devices.

[0165] Based on the implementation methods provided in the above aspects, this application can be further combined to provide more implementation methods. Attached Figure Description

[0166] Figure 1 An exemplary schematic diagram of the architecture of a possible communication system provided in an embodiment of this application is shown;

[0167] Figure 2 An exemplary schematic diagram of a possible O-RAN system architecture provided by an embodiment of this application is shown;

[0168] Figure 3a This illustration shows a schematic diagram of a communication architecture for SL U2N relay in an NTN communication scenario, provided by an embodiment of this application.

[0169] Figure 3b This illustration shows another communication architecture diagram for SL U2N relay in NTN communication scenarios provided by an embodiment of this application;

[0170] Figure 4 An exemplary flowchart of a communication method provided in an embodiment of this application is shown;

[0171] Figure 5 An exemplary flowchart of another communication method provided in an embodiment of this application is shown;

[0172] Figure 6 An exemplary schematic diagram of a communication device provided in an embodiment of this application is shown;

[0173] Figure 7 An exemplary schematic diagram of another communication device provided in an embodiment of this application is shown. Detailed Implementation

[0174] Before introducing the technical solutions provided in this application, some of the terms used in this application will be explained in order to facilitate understanding by those skilled in the art.

[0175] (1) Sidelink (SL): Also known as a side link, side-connected link, direct link, edge link, or auxiliary link, etc. In the embodiments of this application, the above terms all refer to links established between devices of the same type, and their meanings are the same. Devices of the same type can be links between terminal devices, etc. Specifically, links between terminal devices can be device-to-device (D2D) links defined in 3GPP versions (Rel)-12 / 13 / 14 / 15, vehicle-to-vehicle, vehicle-to-mobile phone, or vehicle-to-everything (V2X) links defined by 3GPP for vehicle-to-everything networks, or V2X links based on NR systems in other versions (such as Rel-16 or later versions), etc.

[0176] (2) Reference signal: including at least one of the following: positioning reference signal (PRS), sounding reference signal (SRS), channel state information reference signal (CSI-RS), demodulation reference signal (DMRS), phase-tracking reference signal (PTRS), or synchronization signal and physical broadcast channel block (SSB).

[0177] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0178] The following describes the communication system architecture to which the communication method provided in this application is applicable. It should be noted that this description is for the convenience of those skilled in the art and does not constitute a limitation on the scope of protection claimed in this application.

[0179] The communication scheme provided in this application can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, sidelink (SL) communication systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, 5th Generation (5G) mobile communication systems or new radio access technology (NR), satellite communication systems, etc. Among them, 5G mobile communication systems can include non-standalone (NSA) and / or standalone (SA) networking. The technical solution provided in this application can also be applied to future evolving communication systems. Satellite communication systems can be satellite communication systems integrated with the 4th Generation (4G) mobile communication system, 5G mobile communication system, or future communication systems, such as non-terrestrial networks (NTN), etc. NTN communication systems can be, for example, satellite communication systems, or include unmanned aerial vehicles, high altitude platform stations (HAPS), and other aerial access network equipment; this application does not limit the scope of such systems.

[0180] In a communication system, one network element can send signals to or receive signals from another network element. These signals can include information, signaling, or data. The term "network element" can also be replaced with entities, network entities, devices, communication equipment, communication modules, nodes, communication nodes, etc.

[0181] Figure 1 An exemplary schematic diagram of the architecture of a possible communication system to which embodiments of this application apply is illustrated. For example... Figure 1 As shown, the communication system architecture 10 includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the communication system architecture 10 may also include an Internet 300. RAN 100 includes at least one radio access network device (such as...) Figure 1110a and 110b (collectively referred to as 110) and at least one terminal device (such as Figure 1 RAN 100 includes 120a-120j, collectively referred to as 120. RAN 100 may also include other radio access network equipment, such as radio relay equipment and / or radio backhaul equipment. Figure 1 (Not shown in the image). Terminal device 120 is connected to wireless access network device 110 wirelessly. Wireless access network device 110 is connected to core network 200 wirelessly or via wired connection. The core network device in core network 200 and wireless access network device 110 in RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and wireless access network logical functions, or they can be a single physical device integrating some core network logical functions and some wireless access network logical functions. Terminal devices and wireless access network devices can be interconnected via wired or wireless connections.

[0182] RAN100 can be a 3GPP-related cellular system, such as a 4G, 5G mobile communication system, or a future-oriented evolution system. RAN100 can also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. RAN100 can also be a communication system that integrates two or more of the above systems.

[0183] The following explanations of the devices or network elements involved in the above-mentioned communication system 10 are provided to facilitate understanding by those skilled in the art.

[0184] (1) The wireless access network device 110, sometimes also referred to as access network equipment, RAN entity, network equipment, or access node, constitutes part of the communication system 10 and is used to assist terminal equipment in achieving wireless access. Multiple wireless access network devices 110 in the communication system 10 can be nodes of the same type or different types. In some scenarios, the roles of the wireless access network device 110 and the terminal device 120 are relative, for example, Figure 2 Network element 120i can be a helicopter or a drone, and it can be configured as a mobile base station. For terminal devices 120j that access RAN 100 through network element 120i, network element 120i is a base station; however, for base station 110a, network element 120i is a terminal device. RAN node 110 and terminal device 120 are sometimes referred to as communication devices, for example... Figure 1Network elements 110a and 110b can be understood as communication devices with base station functions, and network elements 120a-120j can be understood as communication devices with terminal equipment functions. Optionally, RAN node 110 can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; it can also be deployed on water; and it can also be deployed in the air on aircraft, drones, balloons, and satellites. This application embodiment does not limit the application scenario of the RAN node.

[0185] In one possible application scenario, the wireless access network device 110 can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a transmission point (TP), a future base station in a 5th generation (5G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc. The wireless access network device 110 can also be a macro base station (such as...) Figure 1 110a), micro base stations or indoor stations (such as Figure 1 The wireless access network device 110 can be a relay node or donor node, or a wireless controller in a CRAN scenario. Optionally, the wireless access network device 110 can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the wireless access network device in V2X technology can be a roadside unit (RSU). All or part of the functions of the wireless access network device 110 in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The wireless access network device 110 in this application can also be a logical node, logical module, or software capable of implementing all or part of the functions of a wireless access network device.

[0186] In another possible application scenario, the wireless access network device 110 can be a module or unit that performs some of the functions of a base station; or multiple wireless access network devices 110 can cooperate to assist the terminal 120 in achieving wireless access, with different wireless access network devices 110 respectively performing some of the functions of a base station. For example, the wireless access network device 110 can be a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a wireless unit (or radio unit, RU), etc. The CU and DU can be set up separately, or they can be included in the same network element, such as in a baseband unit (BBU). The RU can be included in a radio equipment or radio unit, such as in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radiohead (RRH).

[0187] In different systems, CU, DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an open radio access network (ORAN) system, CU can also be called open CU (open-CU, O-CU), DU can also be called open DU (open-DU, O-DU), and RU can also be called open RU (open-RU, O-RU). In this application, any of the following units—CU (or CU control plane (CU-CP), CU user plane (CU-UP), DU, and RU)—can be implemented through software modules, hardware modules, or a combination of software and hardware modules. CU-CP can also be called open CU-CP (open-CU-CP, O-CU-CP), and CU-UP can also be called open CU-UP (open-CU-UP, O-CU-UP).

[0188] The CU and DU can be configured according to the protocol layer functions of the wireless network they implement. For example, the CU can be configured to implement the functions of the Packet Data Convergence Protocol (PDCP) layer and above (e.g., the Radio Resource Control (RRC) layer and / or the Service Data Adaptation Protocol (SDAP) layer); the DU can be configured to implement the functions of the protocol layers below the PDCP layer (e.g., the Radio Link Control (RLC) layer, the Media Access Control (MAC) layer, and / or the Physical (PHY) layer). Alternatively, the CU can be configured to implement the functions of the protocol layers above the PDCP layer (e.g., the RRC and / or SDAP layers), and the DU can be configured to implement the functions of the protocol layers below the PDCP layer (e.g., the RLC, MAC, and / or PHY layers). For specific descriptions of the above protocol layers, please refer to the relevant 3GPP technical specifications or the technical specifications of other applicable communication protocols. The above division of the processing functions of CU and DU according to protocol layers is merely an example; other division methods are also possible, and this application does not limit this. For example, in one design, CU or DU can be further divided into processing functions with protocol layers. In one design, some functions of the RLC layer and the functions of the protocol layer above the RLC layer are located in the CU, while the remaining functions of the RLC layer and the functions of the protocol layer below the RLC layer are located in the DU.

[0189] Figure 2 A schematic diagram of a possible O-RAN system architecture is provided for embodiments of this application. The O-RAN system in the embodiments provided in this application may include... Figure 2 Other components besides those shown. For example... Figure 2 As shown, access network equipment (e.g., eNB, gNB, or future access network equipment) communicates with the core network (CN) via a backhaul link and with terminal equipment via an air interface. For example, the BBU in the access network equipment communicates with the core network via a backhaul link, and the Radio Unit (RU) in the access network equipment communicates with at least one terminal equipment via an air interface. The BBU communicates with at least one RU via a fronthaul link; the BBU and RU may or may not be co-located. The BBU includes at least one Control Unit (CU) and at least one DU, which can communicate via at least one midhaul link.

[0190] It is understood that, in the embodiments of this application, the apparatus for implementing the function of the wireless access network device 110 can be the wireless access network device 110 itself, or it can be an apparatus capable of supporting the wireless access network device 110 in implementing the function, such as a chip system or a combination device or component capable of implementing the function of the wireless access network device. This apparatus can be installed in the wireless access network device 110. The embodiments of this application do not limit the specific technology or specific device form adopted by the wireless access network device 110.

[0191] (2) A terminal device is a device that provides voice or data connectivity to a user. It can also be an Internet of Things (IoT) device, and may be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, etc. Terminal devices can be widely used in various scenarios, such as D2D communication, V2X communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart cities, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, airplanes, ships, robots, robotic arms, smart home devices, etc. The embodiments of this application do not limit the specific technologies and specific device forms used in the terminal devices.

[0192] In the embodiments of this application, the terminal device can be fixed in location or mobile, and this application does not limit this. For example, the terminal device can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted, or it can also be deployed on water (such as ships), or it can also be deployed in the air (such as airplanes, balloons, drones or satellites).

[0193] It is understood that communication between radio access network (RAN) devices, between RAN devices and terminal devices, or between terminal devices can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication between RAN devices and terminal devices can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. This application does not limit the spectrum resources used between RAN nodes and terminal devices.

[0194] In this embodiment, the functions of a wireless access network device (such as a base station) can be executed by a module (such as a chip) within the wireless access network device, or by a control subsystem that includes the functions of the wireless access network device. This control subsystem can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of a terminal device can be executed by a module (such as a chip or modem) within the terminal device, or by a device that includes terminal functions.

[0195] In this embodiment, communication between the terminal device and the radio access network (RAN) device refers to the terminal device sending uplink signals or uplink information to the RAN device, with the uplink information carried on the uplink channel, and / or the RAN device sending downlink signals or downlink information to the terminal device, with the downlink information carried on the downlink channel. For the terminal device to communicate with the RAN device, it needs to establish a radio connection with a cell controlled by the RAN device (i.e., the terminal device resides in a cell controlled by the RAN device). The cell with which the terminal device establishes a radio connection is called the serving cell of the terminal device (i.e., the cell that provides service to the terminal device).

[0196] Optionally, the embodiments of this application can be applied to NTN communication scenarios or terrestrial network communication scenarios. For example, taking the NTN communication scenario as an example, the network device is deployed on a satellite, and the network device can communicate with the terminal device (such as a remote UE) through a relay terminal device (such as a relay UE), or the network device can also communicate directly with the terminal device.

[0197] It is understood that the communication system and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0198] UE-to-network relay (U2N Relay) technology is a technique where one UE assists another UE in communicating with a radio access network device; it is also called relay technology. For example, consider an NTN communication scenario. Please refer to [link to NTN communication scenario]. Figure 3a This is a schematic diagram of a communication architecture for SL U2N relays in NTN communication scenarios. Figure 3aAs shown, when the communication quality between the remote UE and the satellite deteriorates, the remote UE can communicate with radio access network equipment (such as a satellite or a base station deployed on a satellite) through a relay UE. Specifically, in... Figure 3a In this system, the relay UE and the radio access network device can communicate via the Uu interface, while the remote UE and the relay UE can communicate via a side link. For example, the connection between the remote UE and the relay UE can be a PC5 (direct communication interface) connection, or the connection between the remote UE and the relay UE can be a non-3GPP connectivity (N3C) connection, such as a Bluetooth connection or a WiFi connection.

[0199] Please see Figure 3b This is a schematic diagram of another communication architecture for SL U2N relay in NTN communication scenarios. Figure 3b As shown, a remote UE can communicate directly with radio access network (RAN) devices (such as satellites or base stations deployed on satellites). This communication path between the remote UE and RAN devices is called a direct path. A remote UE can also communicate with RAN devices (such as satellites or base stations deployed on satellites) through a relay UE. This allows the remote UE to utilize the relay capability of the relay UE to improve uplink speed, reliability, service stability, and reduce latency. This communication path between the remote UE and RAN devices through a relay UE is called an indirect path. It is understandable that in... Figure 3b In this system, relay UEs and radio access network devices can communicate via the Uu port, remote UEs and radio access network devices can communicate via the Uu port, and remote UEs and relay UEs can communicate via a side link. For example, the connection between a remote UE and a relay UE can be a PC5 connection, or the connection between a remote UE and a relay UE can be a non-3GPP connection, such as a Bluetooth connection or a WiFi connection.

[0200] Regarding the above Figure 3a or Figure 3bThe illustrated communication architecture, based on the mobile characteristics of satellites, provides service to terminal devices in a certain ground area for a limited time, and cannot provide service to terminal devices in that area for extended periods. In this situation, terminal devices in that ground area need to perform frequent satellite handovers. Since relay terminals and remote terminals are close to each other, they usually need to handover together. However, existing protocols (or standards) do not support cross-satellite handovers (e.g., from satellite 1 to satellite 2) between the same relay UE and remote UE while maintaining a cooperative relationship. If it is desired that the remote UE still communicates with satellite 2 through the same relay UE (e.g., relay UE1) after the handover, a cross-satellite handover is required first from a non-direct path (i.e., the path through which the remote UE communicates with satellite 1 via relay UE1) to a direct path (i.e., the path through which the remote UE directly communicates with satellite 2). Simultaneously, relay UE1 also performs a cross-satellite handover (i.e., from relay UE1 communicating with satellite 1 to relay UE1 communicating with satellite 2), and then a same-satellite handover is performed from a direct path to a non-direct path (i.e., the path through which the remote UE communicates with satellite 2 via relay UE1). Understandably, this method also requires relay UE1 and the remote UE to first release the sidelink connection and then re-establish the sidelink connection. Alternatively, the sidelink connection between relay UE1 and the remote UE can be released first, and relay UE1 and the remote UE can each perform cross-satellite handovers. After the cross-satellite handovers are completed, relay UE1 and the remote UE can then re-establish the sidelink connection. Alternatively, if there are other suboptimal relay UEs (such as relay UE2), then a cross-satellite handover is required first from the non-direct path (i.e., the path through which the remote UE communicates with satellite 1 via relay UE1) to the non-direct path (i.e., the path through which the remote UE communicates with satellite 2 via relay UE2), followed by a same-satellite handover from the non-direct path (i.e., the path through which the remote UE communicates with satellite 2 via relay UE2) to the non-direct path (i.e., the path through which the remote UE communicates with satellite 2 via relay UE1). However, the above-mentioned switching methods require a lot of signaling interaction during satellite handover, making the signaling complex and cumbersome, resulting in a large signaling overhead.

[0201] In view of this, this application provides a communication method to enable relay terminals and remote terminals to switch from the source satellite to the target satellite as a whole, thereby effectively reducing signaling overhead.

[0202] The specific implementation of the communication method in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0203] Figure 4 This illustration shows a flowchart of a communication method provided in an embodiment of this application. The method is applicable to... Figure 2 or Figure 3a or Figure 3b The diagram illustrates the communication system architecture. For ease of understanding, Figure 4 This application illustrates the interaction using multiple communication devices (such as a first terminal device, a second terminal device, a first network device, or multiple second network devices) as the execution entities, but it does not limit the execution entities of the interaction. For example, the first network device or the second network device can be a network device, or it can be a component within a network device, such as a communication module, processor, chip, chip system, or circuit that can be applied in an access network device, or it can be a logic module or software that can implement all or part of the functions of the access network device. The first terminal device or the second terminal device can be a terminal device, or it can be a component within a terminal device, such as a communication module, circuit or chip responsible for communication functions (such as a modem chip, also known as a baseband chip, or a system-on-a-chip (SoC) chip or system-in-package (SIP) chip containing a modem core), chip system, or processor that can be applied in a terminal device, or it can be a logic module or software that can implement all or part of the functions of the terminal device. For example, the first terminal device can be a remote UE, the second terminal device can be a relay UE, the first network device can be a source base station, and the second network device can be a target base station (e.g., base station 1). For instance, the first or second network device can be an NTN device. Specifically, an NTN device can be an NTN equipment or a chip (or chip system, circuit, unit, or module) within an NTN equipment. For example, an NTN equipment can be a satellite, a drone, or a high-altitude platform, or it can be a base station device deployed within a satellite, drone, or high-altitude platform.

[0204] like Figure 4 As shown, the communication method includes the following steps.

[0205] S401: The first terminal device and / or the second terminal device send first information to the first network device. Accordingly, the first network device receives the first information.

[0206] The first information can be used by the first network device to determine that the first terminal device and the second terminal device are switching from the first network device to the second network device in the form of a cooperative group. Switching from the first network device to the second network device in the form of a cooperative group can mean (or may refer to) that before the switch, the first terminal device communicated with the first network device through the second terminal device, and after the switch, the first terminal device still communicates with the second network device through the second terminal device.

[0207] Understandably, the form of a collaboration group can refer to the first terminal device and the second terminal device switching simultaneously as a group (or switching together, such as the first terminal device and the second terminal device switching from the first network device to the second network device together (or simultaneously)), or it can refer to the first terminal device and the second terminal device switching together as a whole (such as the first terminal device and the second terminal device switching from the first network device to the second network device as a whole), or it can refer to the second terminal device continuously providing relay services to the first terminal device before and after the switch.

[0208] The first piece of information will be introduced below.

[0209] For example, the first piece of information may refer to measurement results or measurement reports. For instance, measurement results or reports may include one or more of the following: air interface measurement results (such as Uu interface measurement results), side link measurement results, etc. It is understood that air interface measurement results or side link measurement results may include parameters used to reflect signal quality. In the embodiments of this application, the parameters used to reflect signal quality may include, but are not limited to, at least one of the following: reference signal receiving power (RSRP), reference signal receiving quality (RSRQ), or received signal strength indication (RSSI).

[0210] The air interface measurement may include at least one of the following: the measurement result of the first terminal device on the air interface (which can be understood as the measurement result obtained by the first terminal device from measuring the air interface signal) or the measurement result of the second terminal device on the air interface, etc. The side link measurement result may include at least one of the following: the measurement result obtained by the first terminal device from measuring the side link signal or the measurement result obtained by the second terminal device from measuring the side link signal.

[0211] For example, the measurement result of the first terminal device on the air interface may include at least one of the following: the measurement result obtained by the first terminal device measuring the air interface signal between the first terminal device and the first network device, or the measurement result obtained by the first terminal device measuring the air interface signal between the first terminal device and at least one candidate network device (or may be referred to as at least one candidate target network device). The measurement result of the second terminal device on the air interface may include at least one of the following: the measurement result obtained by the second terminal device measuring the air interface signal between the second terminal device and the first network device, or the measurement result obtained by the second terminal device measuring the air interface signal between the second terminal device and at least one candidate network device.

[0212] Optionally, after completing their respective measurements, the first terminal device and the second terminal device can exchange the measurement results obtained from their measurements.

[0213] Based on the above, the first information may include at least one of the following: first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality, or sixth signal quality. The first, second, third, fourth, fifth, and sixth signal qualities are described below.

[0214] (1) First signal quality and second signal quality: The first signal quality is obtained by the first terminal device measuring the signal of the first network device. The second signal quality is obtained by the first terminal device measuring the signal of the second network device.

[0215] For example, the first terminal device can measure a signal (such as a reference signal) from the first network device based on the measurement configuration information sent by the first network device to obtain a first signal quality. The first terminal device can also measure a signal (such as a reference signal) from a second network device based on the measurement configuration information sent by the first network device to obtain a second signal quality. The measurement configuration information can be used by the first terminal device to perform air interface measurements and side-link measurements. For example, the measurement configuration information may include measurement frequency points, measurement timing configurations, measurement reporting trigger conditions (such as periodicity, non-periodicity, event triggering), and measurement objects (such as location, signal quality), etc.

[0216] Understandably, if there is both a direct connection path and a non-direct connection path between the first terminal device and the first network device, the first network device can send the measurement configuration information to the first terminal device via the direct connection path, and / or, it can send the measurement configuration information to the first terminal device via the second terminal device (i.e., a non-direct connection path). For example, "and" here could mean that the first network device sends a portion of the data to the first terminal device via both the direct and non-direct connection paths. For instance, it could send a portion of the bit data corresponding to the measurement configuration information to the first terminal device via the direct connection path, and another portion via the non-direct connection path. If there is no direct connection path between the first terminal device and the first network device, and only a non-direct connection path exists, then the first network device sends the measurement configuration information to the first terminal device via the second terminal device (i.e., a non-direct connection path).

[0217] (2) Third signal quality and fourth signal quality: The third signal quality is obtained by the second terminal device measuring the signal of the first network device. The fourth signal quality is obtained by the second terminal device measuring the signal of the second network device.

[0218] For example, the second terminal device can measure the signal (e.g., a reference signal) from the first network device based on the measurement configuration information sent by the first network device, and obtain a third signal quality. The second terminal device can also measure the signal (e.g., a reference signal) from the second network device based on the measurement configuration information sent by the first network device, and obtain a fourth signal quality. The measurement configuration information can be used by the second terminal device to perform air interface measurements and side link measurements.

[0219] (5) Fifth signal quality: The fifth signal quality can represent the side link signal quality between the first terminal device and the second terminal device.

[0220] For example, the fifth signal quality can refer to the sidelink discovery RSRP (SL_RSRP), or the fifth signal quality can refer to the sidelink discovery RSRP (SD_RSRP).

[0221] The second terminal device and the third terminal device belong to (or are included in) a plurality of candidate terminal devices for providing relay services. That is to say, the second terminal device and the third terminal device are two different candidate terminal devices among a plurality of candidate terminal devices for providing relay services.

[0222] In one example, the fifth signal quality can be obtained by the first terminal device measuring the signal from the second terminal device according to the measurement configuration information issued by the first network device.

[0223] In another example, the fifth signal quality can be obtained by the second terminal device measuring the signal from the first terminal device based on the measurement configuration information issued by the first network device.

[0224] Understandably, whether it is the first terminal device or the second terminal device that measures the quality of the fifth signal, it can transmit the quality of the fifth signal to the other terminal device through the side link.

[0225] (6) Sixth signal quality: The sixth signal quality can refer to the side link signal quality between the first terminal device and the third terminal device. For example, the sixth signal quality can refer to SD_RSRP.

[0226] In one example, the sixth signal quality can be obtained by the first terminal device measuring the signal from the third terminal device based on the measurement configuration information sent by the first network device. Optionally, after obtaining the sixth signal quality, the first terminal device can send the sixth signal quality to the third terminal device via a side link.

[0227] In another example, the sixth signal quality can be obtained by the third terminal device measuring the signal from the first terminal device based on the measurement configuration information sent by the first network device. Optionally, after obtaining the sixth signal quality, the third terminal device can send the sixth signal quality to the first terminal device via a side link.

[0228] The following describes the process of a first terminal device and / or a second terminal device sending first information to a first network device through several possible implementation methods.

[0229] Method A1: After completing the measurement according to the measurement configuration information issued by the first network device, the first terminal device and / or the second terminal device send the first information to the first network device.

[0230] The above method A1 can realize the periodic reporting of measurement results, which makes it easier for the first network device to obtain the corresponding measurement results in a timely and effective manner, and to determine whether the first terminal device and the second terminal device should switch from the first network device to the second network device in the form of a cooperative group based on the measurement results.

[0231] The implementation process of method A1 above will be illustrated through the following possible examples.

[0232] Example a1: The first terminal device sends the first information to the first network device.

[0233] Optionally, in example a1, the first terminal device may carry some or all of the first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality and sixth signal quality in the first information and send them to the first network device.

[0234] For example, the first terminal device may carry one or more of the first, second, third, fourth, fifth, and sixth signal qualities in the first information (i.e., the first information generated by the first terminal device) and send it to the first network device. Optionally, the second terminal device may carry the remaining signal qualities in the first information (i.e., the first information generated by the second terminal device) and send it to the first network device, or the second terminal device may carry the first, second, third, fourth, fifth, and sixth signal qualities in the first information (i.e., the first information generated by the second terminal device) and send it to the first network device.

[0235] For example, the first terminal device may send the first signal quality and the second signal quality to the first network device in the first information. Optionally, the second terminal device may send the third signal quality, the fourth signal quality, the fifth signal quality and the sixth signal quality to the first network device in the first information (i.e., the first information generated by the second terminal device), or the second terminal device may send the third signal quality, the fourth signal quality, the fifth signal quality, the sixth signal quality and at least one of the first signal quality or the second signal quality to the first network device in the first information.

[0236] For example, the first terminal device may send the first signal quality, the second signal quality, and the fifth signal quality to the first network device in the first information (i.e., the first information generated by the first terminal device). Optionally, the second terminal device may send the third signal quality, the fourth signal quality, and the sixth signal quality to the first network device in the first information (i.e., the first information generated by the second terminal device), or the second terminal device may send the third signal quality, the fourth signal quality, the sixth signal quality, and at least one of the first signal quality, the second signal quality, or the fifth signal quality to the first network device in the first information.

[0237] For example, the first terminal device may carry the first signal quality, second signal quality, fifth signal quality, and sixth signal quality in the first information (i.e., the first information generated by the first terminal device) and send it to the first network device. Optionally, the second terminal device may carry the third signal quality and fourth signal quality in the first information (i.e., the first information generated by the second terminal device) and send it to the first network device, or the second terminal device may carry the third signal quality, fourth signal quality, and at least one of the first, second, fifth, or sixth signal quality in the first information and send it to the first network device.

[0238] For example, the first terminal device may carry the first signal quality, the second signal quality, the third signal quality, the fourth signal quality, the fifth signal quality, and the sixth signal quality in the first information and send them to the first network device.

[0239] It is understood that the above content is only an example of several situations in which the first information contains signal quality. There are other situations in which the first information contains signal quality. These other situations can be deduced by analogy in the way described in the above examples, and will not be listed one by one here.

[0240] Optionally, in example a1, if there is both a direct connection path and a non-direct connection path between the first terminal device and the first network device, the first terminal device can send the first information to the first network device through the direct connection path, and / or, it can send the first information to the first network device through a second terminal device (i.e., a non-direct connection path). For example, "and" here could mean that the first terminal device sends a portion of the data to the first network device through both the direct connection path and the non-direct connection path. For instance, it could send a portion of the bit data corresponding to the first information to the first network device through the direct connection path, and another portion of the bit data corresponding to the first information to the first network device through the non-direct connection path. If there is no direct connection path between the first terminal device and the first network device, and only a non-direct connection path exists, then the first terminal device sends the first information to the first network device through the second terminal device (i.e., a non-direct connection path).

[0241] Example a2: The second terminal device sends the first information to the first network device.

[0242] The description of the content of the first information in example a2 can be found in the description of example a1 above, and will not be repeated here.

[0243] Example a3: The first terminal device and the second terminal device respectively send the first information to the first network device.

[0244] It is understandable that when the first terminal device and the second terminal device send the first information to the first network device, the first information sent by the first terminal device to the first network device and the first information sent by the second terminal device to the first network device may be the same or different. It should be understood that "different" here can mean that the first information sent by the first terminal device is partially different from the first information sent by the second terminal device, partially the same, or completely different.

[0245] For example, the first terminal device can send the first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality, and sixth signal quality to the first network device in the first information (i.e., the first information generated by the first terminal device). The second terminal device can send the first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality, and sixth signal quality to the first network device in the first information (i.e., the first information generated by the second terminal device).

[0246] For example, the first terminal device can send the first signal quality along with the first information (i.e., the first information generated by the first terminal device) to the first network device. The second terminal device can send the second, third, fourth, fifth, and sixth signal qualities along with the first information (i.e., the first information generated by the second terminal device) to the first network device.

[0247] For example, the first terminal device may send the first signal quality and the second signal quality to the first network device in the first information (i.e., the first information generated by the first terminal device). Optionally, the second terminal device may send the third signal quality, the fourth signal quality, the fifth signal quality, and the sixth signal quality to the first network device in the first information (i.e., the first information generated by the second terminal device).

[0248] For example, the first terminal device may send the first signal quality, the second signal quality, and the fifth signal quality to the first network device in the first information. Optionally, the second terminal device may send the third signal quality, the fourth signal quality, and the sixth signal quality to the first network device in the first information (i.e., the first information generated by the second terminal device).

[0249] For example, the first terminal device may send the first signal quality, second signal quality, fifth signal quality, and sixth signal quality to the first network device in the first information (i.e., the first information generated by the first terminal device). Optionally, the second terminal device may send the third signal quality and fourth signal quality to the first network device in the first information (i.e., the first information generated by the second terminal device).

[0250] It is understood that the above content is only an example of several situations in which the first information sent by the first terminal device and the second terminal device contain signal quality. There are other situations in which the first information contains signal quality. These other situations can be deduced by analogy in the manner described in the above examples, and will not be listed one by one here.

[0251] Optionally, in example a3, if there is both a direct connection path and a non-direct connection path between the first terminal device and the first network device, the first terminal device can send the first information to the first network device through the direct connection path, and / or, it can send the first information to the first network device through the second terminal device (i.e., the non-direct connection path). It should be understood that the meaning of "and" here can be found in the relevant description above, and will not be repeated here. If there is no direct connection path between the first terminal device and the first network device, and only a non-direct connection path exists, the first terminal device sends the first information to the first network device through the second terminal device (i.e., the non-direct connection path).

[0252] Method A2: After completing the measurement according to the measurement configuration information issued by the first network device, the first terminal device and / or the second terminal device may send the first information to the first network device if at least one of the following conditions q1 to q7 is met.

[0253] Condition q1: The difference between the quality of the fourth signal and the quality of the third signal is greater than or equal to the sixth threshold.

[0254] Optionally, the difference between the fourth signal quality and the third signal quality being greater than or equal to a sixth threshold can include: the difference between the fourth signal quality and the third signal quality being greater than or equal to the sixth threshold, and the duration of this difference being greater than or equal to the sixth threshold being greater than or equal to a first time threshold. That is, condition q1 can be understood as either the difference between the fourth signal quality and the third signal quality being greater than or equal to the sixth threshold, or the difference between the fourth signal quality and the third signal quality being greater than or equal to the sixth threshold and the duration of this difference being greater than or equal to the sixth threshold being greater than or equal to a first time threshold.

[0255] Condition q2: The difference between the fourth signal quality and the maximum signal quality among the first and second signal qualities is greater than or equal to the seventh threshold.

[0256] Optionally, the condition that the difference between the fourth signal quality and the maximum signal quality among the first and second signal qualities is greater than or equal to the seventh threshold can include: the difference between the fourth signal quality and the maximum signal quality among the first and second signal qualities is greater than or equal to the seventh threshold, and the duration for which this difference is greater than or equal to the seventh threshold is greater than or equal to the second time threshold. That is, condition q2 can be understood as either the difference between the fourth signal quality and the maximum signal quality among the first and second signal qualities being greater than or equal to the seventh threshold, or the difference between the fourth signal quality and the maximum signal quality among the first and second signal qualities being greater than or equal to the seventh threshold, and the duration for which this difference is greater than or equal to the seventh threshold being greater than or equal to the second time threshold.

[0257] Condition q3: The quality of the fifth signal is greater than or equal to the eighth threshold.

[0258] Condition q4: The difference between the quality of the fifth signal and the quality of the sixth signal is greater than or equal to the ninth threshold.

[0259] Condition q5: The difference between the quality of the fourth signal and the quality of the first signal is greater than or equal to the tenth threshold.

[0260] Optionally, the condition that the difference between the fourth signal quality and the first signal quality is greater than or equal to the tenth threshold may include: the difference between the fourth signal quality and the first signal quality is greater than or equal to the tenth threshold, and the duration for which this difference is greater than or equal to the tenth threshold is greater than or equal to the third time threshold. That is, condition q5 can be understood as either the difference between the fourth signal quality and the first signal quality being greater than or equal to the tenth threshold, or the difference between the fourth signal quality and the first signal quality being greater than or equal to the tenth threshold, and the duration for which this difference is greater than or equal to the tenth threshold being greater than or equal to the third time threshold.

[0261] Condition q6: The difference between the quality of the fourth signal and the quality of the second signal is greater than or equal to the eleventh threshold.

[0262] Optionally, the condition that the difference between the fourth signal quality and the second signal quality is greater than or equal to the eleventh threshold can include: the difference between the fourth signal quality and the second signal quality is greater than or equal to the eleventh threshold, and the duration for which this difference is greater than or equal to the eleventh threshold is greater than or equal to the fourth time threshold. That is, condition q6 can be understood as either the difference between the fourth signal quality and the second signal quality being greater than or equal to the eleventh threshold, or the difference between the fourth signal quality and the second signal quality being greater than or equal to the eleventh threshold, and the duration for which this difference is greater than or equal to the eleventh threshold is greater than or equal to the fourth time threshold.

[0263] Condition q7: The difference between the quality of the second signal and the quality of the first signal is greater than or equal to the twelfth threshold.

[0264] Optionally, the difference between the second signal quality and the first signal quality being greater than or equal to the twelfth threshold can include: the difference between the second signal quality and the first signal quality being greater than or equal to the twelfth threshold, and the duration of this difference being greater than or equal to the fifth time threshold. That is, condition q7 can be understood as either the difference between the second signal quality and the first signal quality being greater than or equal to the twelfth threshold, or the difference between the second signal quality and the first signal quality being greater than or equal to the twelfth threshold, and the duration of this difference being greater than or equal to the fifth time threshold.

[0265] For example, taking the first terminal device as a remote UE and the second terminal device as a relay UE, the first signal quality is... The second signal quality is The quality of the third signal is The fourth signal quality is The fifth signal quality is SL_RSRP, the sixth signal quality is SD_RSRP, the sixth threshold is P1, the seventh threshold is P2, the eighth threshold is P3, the ninth threshold is P4, the tenth threshold is P5, the eleventh threshold is P6, and the twelfth threshold is P7, for example. Conditions q1 to q7 above can include:

[0266]

[0267] SL_RSRP≥P3(3)

[0268] SL_RSRP-SD_RSRP≥P4(4)

[0269]

[0270] Compared to method A1, method A2 only reports the measurement results to the first network device when at least one of the above conditions is met, without periodically reporting the measurement results to the first network device. Therefore, it can effectively reduce the number of times the measurement results are reported, which helps to save signaling overhead.

[0271] The implementation process of method A2 described above is illustrated below through several possible examples.

[0272] Example b1: The first terminal device sends first information to the first network device when at least one of the above conditions is met.

[0273] For example, if at least one of the above conditions is met, the first terminal device may send one or more of the first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality, and sixth signal quality to the first network device in the first information (i.e., the first information generated by the first terminal device). Optionally, if at least one of the above conditions is met, the second terminal device may also send the remaining signal quality in the first information (i.e., the first information generated by the second terminal device) to the first network device, or it may send the first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality, and sixth signal quality in the first information (i.e., the first information generated by the second terminal device) to the first network device.

[0274] For example, if at least one of the above conditions is met, the first terminal device may send the first signal quality and the second signal quality in the first information (i.e., the first information generated by the first terminal device) to the first network device. Optionally, if at least one of the above conditions is met, the second terminal device may also send the third signal quality, the fourth signal quality, the fifth signal quality, and the sixth signal quality in the first information (i.e., the first information generated by the second terminal device) to the first network device, or it may send the third signal quality, the fourth signal quality, the fifth signal quality, the sixth signal quality, and at least one of the first signal quality or the second signal quality in the first information (i.e., the first information generated by the second terminal device) to the first network device.

[0275] For example, if at least one of the above conditions is met, the first terminal device may send the first signal quality, the second signal quality, and the fifth signal quality in the first information (i.e., the first information generated by the first terminal device) to the first network device. Optionally, if at least one of the above conditions is met, the second terminal device may also send the third signal quality, the fourth signal quality, and the sixth signal quality in the first information (i.e., the first information generated by the second terminal device) to the first network device, or it may send the third signal quality, the fourth signal quality, the sixth signal quality, and at least one of the first signal quality, the second signal quality, or the fifth signal quality in the first information (i.e., the first information generated by the second terminal device) to the first network device.

[0276] For example, if at least one of the above conditions is met, the first terminal device may send the first signal quality, second signal quality, fifth signal quality, and sixth signal quality to the first network device in the first information (i.e., the first information generated by the first terminal device). Optionally, if at least one of the above conditions is met, the second terminal device may also send the third signal quality and fourth signal quality to the first network device in the first information (i.e., the first information generated by the second terminal device), or it may send the third signal quality, fourth signal quality, and at least one of the first, second, fifth, or sixth signal quality in the first information (i.e., the first information generated by the second terminal device) to the first network device.

[0277] For example, if at least one of the above conditions is met, the first terminal device may send the first signal quality, the second signal quality, the third signal quality, the fourth signal quality, the fifth signal quality, and the sixth signal quality to the first network device in the first information (i.e., the first information generated by the first terminal device).

[0278] It is understood that the above content is only an example of several situations in which the first information contains signal quality. There are other situations in which the first information contains signal quality. These other situations can be deduced by analogy in the way described in the above examples, and will not be listed one by one here.

[0279] Optionally, in example b1, if there is both a direct connection path and a non-direct connection path between the first terminal device and the first network device, the first terminal device can send the first information to the first network device through the direct connection path, or it can send the first information to the first network device through the second terminal device (i.e., the non-direct connection path). If there is no direct connection path between the first terminal device and the first network device, and only a non-direct connection path exists, the first terminal device sends the first information to the first network device through the second terminal device (i.e., the non-direct connection path).

[0280] Example b2: The second terminal device sends first information to the first network device when at least one of the above conditions is met.

[0281] For example, if at least one of the above conditions is met, the second terminal device may send one or more of the first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality and sixth signal quality to the first network device in the first information.

[0282] For example, if at least one of the above conditions is met, the second terminal device can send the third signal quality and the fourth signal quality to the first network device in the first information.

[0283] For example, if at least one of the above conditions is met, the second terminal device can send the first signal quality and the second signal quality to the first network device in the first information.

[0284] For example, if at least one of the above conditions is met, the second terminal device can send the first signal quality, the second signal quality, and the fifth signal quality to the first network device in the first information.

[0285] For example, if at least one of the above conditions is met, the second terminal device may send the third signal quality, the fourth signal quality, and the fifth signal quality to the first network device in the first information.

[0286] For example, if at least one of the above conditions is met, the second terminal device can send the first signal quality, the third signal quality, and the fifth signal quality to the first network device in the first information.

[0287] For example, if at least one of the above conditions is met, the second terminal device can send the first signal quality, the fourth signal quality, and the fifth signal quality to the first network device in the first information.

[0288] It is understood that the above content is only an example of several situations in which the first information contains signal quality. There are other situations in which the first information contains signal quality. These other situations can be deduced by analogy in the way described in the above examples, and will not be listed one by one here.

[0289] Example b3: The first terminal device and the second terminal device send the first information to the first network device when at least one of the above conditions is met.

[0290] For example, if at least one of the above conditions is met, the first terminal device may send the first signal quality along with the first information to the first network device. The second terminal device may also send the first signal quality along with the first information to the first network device, or send the second signal quality along with the first information to the first network device, or send the third signal quality along with the first information to the first network device, or send the first and third signal quality along with the first information to the first network device, or send the second and third signal quality along with the first information to the first network device, or send the first and second signal quality along with the first information to the first network device, etc., if at least one of the above conditions is met.

[0291] For example, if at least one of the above conditions is met, the first terminal device can send the second signal quality along with the first information to the first network device. The second terminal device can also, if at least one of the above conditions is met, send the second signal quality along with the first information to the first network device, or send the first signal quality along with the first information to the first network device, or send the third signal quality along with the first and third signal qualities along with the first information to the first network device, or send the second and third signal qualities along with the first and second signal qualities along with the first information to the first network device, or send the first, second, and third signal qualities along with the first, second, and fourth signal qualities along with the first and fourth signal qualities along with the first information to the first network device, etc.

[0292] For example, if at least one of the above conditions is met, the first terminal device can send the first signal quality and the second signal quality along with the first information to the first network device. Similarly, if at least one of the above conditions is met, the second terminal device can send the first signal quality and the second signal quality along with the first information to the first network device, or send the third signal quality and the fourth signal quality along with the first information to the first network device, or send the first signal quality, the second signal quality, and the third signal quality along with the first information to the first network device, or send the first signal quality, the second signal quality, the third signal quality, and the fourth signal quality along with the first information to the first network device, and so on.

[0293] For example, if at least one of the above conditions is met, the first terminal device can send the first signal quality, the second signal quality, and the fifth signal quality to the first network device in the first information. The second terminal device may also, under the condition of satisfying at least one of the above conditions, send the first signal quality, the second signal quality, and the fifth signal quality in the first information to the first network device, or send the third signal quality and the fourth signal quality in the first information to the first network device, or send the third signal quality, the fourth signal quality, and the fifth signal quality in the first information to the first network device, or send the third signal quality, the fourth signal quality, and the sixth signal quality in the first information to the first network device, or send the first signal quality, the second signal quality, and the third signal quality in the first information to the first network device, or send the first signal quality, the second signal quality, the third signal quality, the fourth signal quality, and the fifth signal quality in the first information to the first network device, or send the first signal quality, the second signal quality, the third signal quality, the fourth signal quality, and the fifth signal quality in the first information to the first network device, or send the first signal quality, the second signal quality, the third signal quality, the fourth signal quality, the fifth signal quality, and the sixth signal quality in the first information to the first network device, etc.

[0294] It is understood that the above content is only an example of several situations in which the first information sent by the first terminal device and the second terminal device contain signal quality. There are other situations in which the first information contains signal quality. These other situations can be deduced by analogy in the manner described in the above examples, and will not be listed one by one here.

[0295] In one possible implementation, the first terminal device and / or the second terminal device may send first information to the first network device after determining that the handover mode (also referred to as handover capability) of the first terminal device and the second terminal device is a cooperative group handover mode (also referred to as cooperative group handover capability). The cooperative group handover mode can indicate that the first terminal device and the second terminal device are switching from the first network device to the target network device in the form of a cooperative group. For example, the target network device may include the second network device. With this implementation, the first terminal device and / or the second terminal device can send only a portion of the measurement results to the first network device. This allows the first network device to accurately determine whether to switch the first terminal device and the second terminal device from the first network device to the second network device in the form of a cooperative group, helping to reduce the number of measurement results reported and thus saving measurement reporting overhead.

[0296] The following examples illustrate the process by which a first terminal device and / or a second terminal device send first information to a first network device after determining that the switching mode of the first terminal device and the second terminal device is a cooperative group switching mode.

[0297] Example c1: After determining that the switching mode between the first terminal device and the second terminal device is the cooperative group switching mode, the first terminal device sends the first information to the first network device.

[0298] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the first terminal device can send the second signal quality along with the first information to the first network device.

[0299] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the first terminal device can send the first signal quality and the second signal quality in the first information to the first network device.

[0300] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the first terminal device can send the second signal quality and the fourth signal quality to the first network device in the first information.

[0301] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the first terminal device can send the first signal quality and the fourth signal quality in the first information to the first network device.

[0302] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the first terminal device can send the first signal quality, the second signal quality and the third signal quality in the first information to the first network device.

[0303] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the first terminal device can send the first signal quality, the second signal quality and the fourth signal quality in the first information to the first network device.

[0304] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the first terminal device can send the first signal quality, the second signal quality, the third signal quality and the fourth signal quality in the first information to the first network device.

[0305] Understandably, in example c1, it is sufficient for the first terminal device to send the first information to the first network device, and it is not necessary for the second terminal device to send the first information to the first network device.

[0306] It is understood that the above content is only an example of several situations in which the signal quality of the first information sent by the first terminal device is contained. There are other situations in which the signal quality of the first information is contained. These other situations can be deduced by analogy in the manner described in the above examples, and will not be listed one by one here.

[0307] Example c2: After determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the second terminal device sends the first information to the first network device.

[0308] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the second terminal device can send the fourth signal quality along with the first information to the first network device.

[0309] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the second terminal device can send the third signal quality and the fourth signal quality to the first network device in the first information.

[0310] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the second terminal device can send the second signal quality and the fourth signal quality to the first network device in the first information.

[0311] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the second terminal device can send the first signal quality and the fourth signal quality in the first information to the first network device.

[0312] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the second terminal device can send the first signal quality, the third signal quality and the fourth signal quality in the first information to the first network device.

[0313] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the second terminal device can send the second signal quality, the third signal quality and the fourth signal quality in the first information to the first network device.

[0314] For example, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the second terminal device can send the first signal quality, the second signal quality, the third signal quality and the fourth signal quality in the first information to the first network device.

[0315] Understandably, in example c2, it is sufficient for the second terminal device to send the first information to the first network device; it is not necessary for the first terminal device to send the first information to the first network device.

[0316] It is understood that the above content is only an example of several situations in which the signal quality of the first information sent by the second terminal device is exemplified. There are other situations in which the signal quality of the first information is exemplified. These other situations can be deduced by analogy in the manner described in the above examples, and will not be listed one by one here.

[0317] Example c3: After determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the first terminal device and the second terminal device respectively send the first information to the first network device.

[0318] For example, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the first terminal device can send the second signal quality along with the first information to the first network device. Similarly, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the second terminal device can send the third, fourth, fifth, or sixth signal quality along with the first information to the first network device; or send the first and fourth signal quality along with the first information; or send the second and fourth signal quality along with the first information; or send the second, fourth, and fifth signal quality along with the first information; or send the third and fourth signal quality along with the first information; or send the first, third, and fourth signal quality along with the first information, and so on.

[0319] For example, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the first terminal device can send the first signal quality and the second signal quality along with the first information to the first network device. Similarly, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the second terminal device can send the third signal quality and the fourth signal quality along with the first information to the first network device, or send the second signal quality, the third signal quality, and the fourth signal quality along with the first information to the first network device, or send the first signal quality, the second signal quality, the third signal quality, and the fourth signal quality along with the first information to the first network device, or send the first signal quality, the second signal quality, the third signal quality, and the fourth signal quality along with the first information to the first network device, and so on.

[0320] For example, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the first terminal device can send the second signal quality and the fourth signal quality along with the first information to the first network device. Similarly, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the second terminal device can send the first signal quality, or the third signal quality, the fifth signal quality, or the sixth signal quality along with the first information to the first network device; or send the first signal quality, the second signal quality, and the fourth signal quality along with the first information to the first network device; or send the first signal quality, the third signal quality, and the fourth signal quality along with the first information to the first network device; or send the first signal quality, the second signal quality, the third signal quality, and the fourth signal quality along with the first information to the first network device; or send the first signal quality, the second signal quality, the third signal quality, and the fourth signal quality along with the first information to the first network device; or send the first signal quality, the second signal quality, the third signal quality, and the fourth signal quality along with the first information to the first network device; and so on.

[0321] For example, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the first terminal device can send the first signal quality, second signal quality, and third signal quality along with the first information to the first network device. Similarly, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the second terminal device can send the fourth, fifth, or sixth signal quality along with the first information to the first network device; or send the fourth and fifth signal quality along with the first information to the first network device; or send the first, second, third, and fourth signal quality along with the first information to the first network device; or send the first, second, third, and fifth signal quality along with the first information to the first network device; or send the first, second, third, fourth, and fifth signal quality along with the first information to the first network device; and so on.

[0322] Optionally, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the first terminal device may send the first signal quality, second signal quality, third signal quality, and fourth signal quality along with the first information to the first network device. Similarly, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the second terminal device may send the fifth signal quality and sixth signal quality along with the first information to the first network device, or send the third signal quality, fourth signal quality, and fifth signal quality along with the first information to the first network device, or send the third signal quality, fourth signal quality, fifth signal quality, and sixth signal quality along with the first information to the first network device, or send the second signal quality, third signal quality, fourth signal quality, and fifth signal quality along with the first information to the first network device, and so on.

[0323] It is understood that the above content is only an example of several situations in which the first information sent by the first terminal device and the second terminal device contain signal quality. There are other situations in which the first information contains signal quality. These other situations can be deduced by analogy in the manner described in the above examples, and will not be listed one by one here.

[0324] The following section uses a first terminal device as an example to illustrate the implementation process of the first terminal device determining that the switching mode between the first terminal device and the second terminal device is the cooperative group switching mode through several possible implementation methods. It is understood that the implementation process of the second terminal device determining that the switching mode between the first terminal device and the second terminal device is the cooperative group switching mode can refer to the implementation process of the first terminal device determining that the switching mode between the first terminal device and the second terminal device is the cooperative group switching mode, and will not be repeated here.

[0325] Method B1: The first network device sends third information to the first terminal device. This third information can be used to indicate that the handover mode between the first and second terminal devices is a cooperative group handover mode. After receiving the third information, the first terminal device can determine that the handover mode between itself and the second terminal device is the cooperative group handover mode based on the third information. It is understood that the first network device can also send the third information to the second terminal device.

[0326] It should be understood that the circumstances under which the first network device sends third information to the first terminal device are not limited in the embodiments of this application. For example, before the first network device sends third information to the first terminal device, the first network device may receive fourth information from the first terminal device. This fourth information can be used to determine that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode. Afterwards, the first network device can determine that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode based on the fourth information. Optionally, the first network device may also receive fourth information from the second terminal device. Thus, when the first network device receives fourth information from the second terminal device, it can determine that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode based on the fourth information from the second terminal device. When the first network device receives both fourth information from the first terminal device and fourth information from the second terminal device, it can determine that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode based on both fourth information from the first terminal device and fourth information from the second terminal device.

[0327] Optionally, if there is both a direct connection path and a non-direct connection path between the first terminal device and the first network device, the first terminal device can send the fourth information to the first network device through the direct connection path, and / or, it can send the fourth information to the first network device through the second terminal device (i.e., the non-direct connection path). For example, "and" here could mean that the first terminal device sends a portion of the data to the first network device through both the direct connection path and the non-direct connection path. For instance, it could send a portion of the bit data corresponding to the fourth information to the first network device through the direct connection path, and another portion of the bit data corresponding to the fourth information to the first network device through the non-direct connection path. If there is no direct connection path between the first terminal device and the first network device, and only a non-direct connection path exists, then the first terminal device sends the fourth information to the first network device through the second terminal device (i.e., the non-direct connection path).

[0328] For example, the fourth information may include at least one of the following: the handover mode of the first terminal device and the second terminal device is a cooperative group handover mode; the sidelink signal quality between the first terminal device and the second terminal device; the first location information of the first terminal device; the second location information of the second terminal device; the path loss between the first terminal device and the second terminal device; the identifier of the first serving cell of the first terminal device; the identifier of the first serving beam of the first terminal device; the identifier of the second serving cell of the second terminal device; the identifier of the second serving beam of the second terminal device; the first visibility information of the first terminal device to the first network device; the second visibility information of the second terminal device to the first network device; the third visibility information of the first terminal device to the second network device; the fourth visibility information of the second terminal device to the second network device; the first movement trajectory information of the first terminal device; the second movement trajectory information of the second terminal device; the first attitude information (or antenna panel orientation information) of the first terminal device; or the second attitude information (or antenna panel orientation information) of the second terminal device. Optionally, the fourth information may also include the signal quality obtained by the first terminal device measuring the signal from the first network device in multiple directions, the signal quality obtained by the second terminal device measuring the signal from the first network device in multiple directions, the signal quality obtained by the first terminal device measuring the signal from the second network device in multiple directions, or the signal quality obtained by the second terminal device measuring the signal from the second network device in multiple directions, etc.

[0329] The path loss can be determined by the first terminal device based on the transmission quality (e.g., transmission power) and reception quality (e.g., reception power) of the signal from the second terminal device, or it can be determined by the second terminal device based on the transmission quality and reception quality of the signal from the first terminal device.

[0330] For example, the first or second visibility information may include the angular range at which the first or second terminal device can see the first network device, the time period during which the first network device can be seen, and the duration of time during which the first network device can be seen. The third or fourth visibility information may include the angular range at which the first or second terminal device can see the second network device, the time period during which the second network device can be seen, and the duration of time during which the second network device can be seen.

[0331] In one possible implementation, if the fourth information includes a cooperative group handover mode, the first network device can determine that the handover mode of the first terminal device and the second terminal device is a cooperative group handover mode based on the cooperative group handover mode included in the fourth information.

[0332] In another possible implementation, if the fourth information includes a cooperative group handover mode, or if the fourth information does not include a cooperative group handover mode, the first network device may determine that the handover mode of the first terminal device and the second terminal device is a cooperative group handover mode if at least one of the following conditions j1 to j11 is met.

[0333] Condition j1: The quality of the side link signal between the first terminal device and the second terminal device is greater than or equal to the first threshold.

[0334] Condition j2: The distance between the first terminal device and the second terminal device is less than or equal to a distance threshold. The distance between the first terminal device and the second terminal device is determined by the first network device based on the first location information of the first terminal device and the second location information of the second terminal device.

[0335] Condition j3: The path loss between the first terminal device and the second terminal device is less than or equal to the loss threshold.

[0336] Condition j4: The identifier of the first serving cell of the first terminal device is the same as the identifier of the second serving cell of the second terminal device.

[0337] Condition j5: The identifier of the first service beam of the first terminal device is the same as the identifier of the second service beam of the second terminal device.

[0338] Condition j6: The matching degree between the first visible information of the first terminal device to the first network device and the second visible information of the second terminal device to the first network device is greater than or equal to the second threshold.

[0339] Condition j7: The matching degree between the third visible information of the first terminal device to the second network device and the fourth visible information of the second terminal device to the second network device is greater than or equal to the third threshold.

[0340] Condition j8: The distance between the movement trajectory of the first terminal device and the movement trajectory of the second terminal device is less than or equal to the fourth threshold. Here, the movement trajectory of the first terminal device is determined by the first network device based on the first movement trajectory information of the first terminal device, and the movement trajectory of the second terminal device is determined by the first network device based on the second movement trajectory information of the second terminal device.

[0341] Condition j9: The difference between the attitude angles of the first terminal device and the second terminal device is less than or equal to the fifth threshold. Here, the attitude angle of the first terminal device is determined by the first network device based on the first attitude information of the first terminal device, and the attitude angle of the second terminal device is determined by the first network device based on the second attitude information of the second terminal device.

[0342] Condition j10: The difference between the signal quality obtained by the first terminal device from the signal from the first network device in multiple directions and the signal quality obtained by the second terminal device from the signal from the first network device in multiple directions is less than or equal to the thirteenth threshold.

[0343] Condition j11: The difference between the signal quality obtained by the first terminal device from the signal from the second network device in multiple directions and the signal quality obtained by the second terminal device from the signal from the second network device in multiple directions is less than or equal to the fourteenth threshold.

[0344] It is understood that the “first threshold to fourteenth threshold, distance threshold, and loss threshold” mentioned in the embodiments of this application can be configured (or indicated) by the first network device, or can be predefined by the protocol, without any specific restrictions.

[0345] Optionally, after determining that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode, the first network device may send third information to the first terminal device and / or the second terminal device.

[0346] Optionally, after determining that the handover mode of the first terminal device and the second terminal device is a cooperative group handover mode, the first network device may also send a seventh message to the second network device. The second network device can then receive the seventh message from the first network device. The seventh message can be used to indicate that the handover mode of the first terminal device and the second terminal device is a cooperative group handover mode. By sending the seventh message to the second network device, the second network device can promptly learn that the handover mode of the first terminal device and the second terminal device is a cooperative group handover mode and record (or store) this handover mode for later use, without needing to subsequently re-determine the handover mode of the first terminal device and the second terminal device. This helps save costs (such as computational costs, resource costs, or power costs). Alternatively, this method also eliminates the need for the first terminal device or the second terminal device to subsequently report the handover mode of the first terminal device and the second terminal device to the second network device, thus helping to save communication costs.

[0347] Method B2: The first terminal device may determine the switching mode of the first terminal device and the second terminal device as the cooperative group switching mode if at least one of the above conditions j1 to j11 is met.

[0348] In this embodiment, after determining that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode, the first terminal device may send an eighth message to the first network device. Subsequently, the first network device may receive the eighth message from the first terminal device. The eighth message can be used to indicate that the switching mode between the first terminal device and the second terminal device is a cooperative group switching mode.

[0349] Optionally, after receiving the eighth information, the first network device may also send the seventh information to the second network device. The second network device can then receive the seventh information from the first network device. The seventh information can be used to indicate that the switching mode between the first and second terminal devices is a cooperative group switching mode.

[0350] S402: The first network device sends the fifth information to the second network device. Accordingly, the second network device receives the fifth information.

[0351] The fifth piece of information can be used to request the first terminal device and the second terminal device to be switched from the first network device to the second network device in the form of a cooperative group.

[0352] For example, the fifth piece of information could be a handover request.

[0353] For example, the fifth piece of information may include the local identifier of the first terminal device under the first network device, the layer 2 (L2) identifier of the first terminal device under the first network device, the local identifier of the second terminal device under the first network device, or the layer 2 identifier of the second terminal device under the first network device, etc. Optionally, the fifth piece of information may also include the time information of the first terminal device and the second terminal device switching to the second network device in the form of a cooperative group, the location information of the first terminal device, the location information of the second terminal device, or other information related to the cooperative group switching. For example, the time information may be the time point or time range at which the first terminal device and the second terminal device disconnect from the first network device, or the time information may be the time point or time range at which the first terminal device and the second terminal device access the first network device.

[0354] In this embodiment of the application, after receiving the first information, the first network device can determine that the first terminal device and the second terminal device have switched from the first network device to the second network device in the form of a cooperative group, provided that at least one of the conditions q1 to q7 is met. Afterwards, the first network device can send the fifth information to the second network device. It is understood that the description of the first information received by the first network device can be found in the descriptions of Examples b1 to b3 and Examples c1 to c3 above, and will not be repeated here.

[0355] In one possible implementation, the first network device may also send the fifth information to the second network device under other circumstances. For example, other circumstances may include at least one of the following: the remaining service time of the first network device is less than a certain threshold, or the distance between the reference location of the source cell and the terminal location is greater than a certain threshold, or the angle between the line connecting the source cell and the reference location or the terminal location and the horizontal plane exceeds a certain range.

[0356] S403: The second network device sends the sixth information to the first network device. Accordingly, the first network device receives the sixth information.

[0357] In this embodiment of the application, after receiving the fifth information from the first network device, the second network device can perform admission control. For example, the second network device can configure resources required for handover for the first terminal device and the second terminal device, such as at least one of the following: cell radio network temporary identifier (C-RNTI), preamble, random access channel occasion (RO), and time-frequency resources required for handover.

[0358] If the second network device grants access (which can be understood as deciding to accept the handover request), the second network device can send a sixth message to the first network device. For example, the sixth message could be a handover request acknowledgement message.

[0359] For example, the sixth information may include configuration information required for the first terminal device to communicate under the second network device and configuration information required for the second terminal device to communicate under the second network device.

[0360] The configuration information required for the first terminal device to communicate with the second network device may include at least one of the following: relay configuration information, end-to-end wireless bearer information, or access configuration information, etc.

[0361] For example, relay configuration information may include at least one of the following: the local identifier of the first terminal device under the second network device, the Layer 2 identifier of the first terminal device under the second network device, the Layer 2 identifier of the second terminal device under the second network device, or PC5 relay RLC channel configuration information, etc. End-to-end radio bearer information can be found in the relevant description in 3GPP TS38.331. Access configuration information may include at least one of the following: the cell identifier of the second network device, or access information (such as access resources) used for the first terminal device to access the second network device.

[0362] The configuration information required for the second terminal device to communicate with the second network device includes at least one of the following: relay configuration information, bearer mapping configuration information, or access configuration information, etc.

[0363] For example, relay configuration information may include at least one of the following: the local identifier of the second terminal device under the second network device, the Layer 2 identifier of the second terminal device under the second network device, the local identifier of the first terminal device under the second network device, the Layer 2 identifier of the first terminal device under the second network device, PC5 relay RLC channel configuration information, or air interface relay RLC channel configuration information. Bearer mapping configuration information can be found in the relevant description in 3GPP TS38.331. Access configuration information may include at least one of the following: the cell identifier of the second network device, or access information used for the second terminal device to access the second network device.

[0364] S404: The first network device sends second information to the first terminal device and / or the second terminal device. Accordingly, the first terminal device and / or the second terminal device receives the second information.

[0365] In this embodiment of the application, after receiving the sixth information from the second network device, the first network device may send the second information to the first terminal device and / or the second terminal device.

[0366] The second information can be used to instruct the first terminal device and the second terminal device to switch from the first network device to the second network device in a cooperative group. In other words, the second information can trigger the first and second terminal devices to switch network devices in a cooperative group. Upon receiving the second information, the first terminal device can immediately stop transmitting user plane and control plane data with the first network device. Similarly, upon receiving the second information, the second terminal device can also immediately stop transmitting user plane and control plane data with the first network device.

[0367] For example, the second information could be RRC reconfiguration information.

[0368] In one example, when the second information is sent to the first terminal device, the second information may include at least one of the following: relay configuration information, end-to-end radio bearer information, or access configuration information. The relevant descriptions of relay configuration information, end-to-end radio bearer information, and access configuration information can be found in the introduction to the configuration information required for the first terminal device to communicate with the second network device in step 403 above, and will not be repeated here.

[0369] In another example, when the second information is sent to the second terminal device, the second information may include at least one of the following: relay configuration information, bearer mapping configuration information, or access configuration information. The relevant descriptions of relay configuration information, end-to-end radio bearer information, and access configuration information can be found in the introduction to the configuration information required for the second terminal device to communicate under the second network device in step 403 above, and will not be repeated here.

[0370] Optionally, the second information may also include configuration parameters of the cell of the second network device, such as the cell identifier of the second network device, the frequency point of the cell of the second network device, C-RNTI, preamble, RO or time-frequency resources, at least one of them.

[0371] Optionally, the first network device may also send sequence number (SN) status transfer information to the second network device. The second network device can then receive the SN status transfer information. The SN status transfer information can be used to convey the uplink and downlink PDCP sequence number status of the data radio bearer (DRB) of the first terminal device. For example, the SN status transfer information may include the sequence number of a data packet that the first network device has transmitted to the terminal device.

[0372] In one possible implementation, if the first terminal device is in a non-direct connection path scenario (meaning the first terminal device needs to transmit data with the second network device through a second terminal device), the second terminal device can initiate random access to the second network device based on the received second information. This means sending random access information (or random access request information) to the second network device to request access to the cell of the second network device. After receiving the random access information, the second network device can send a random access response (RAR) to the second terminal device. For example, the random access response information may include a random access preamble identifier (RA), timing alignment information, initial uplink grant, or temporary cell radio network temporary identity (TC-RNTI). Understandably, the specific implementation of random access between the second terminal device and the second network device can refer to existing random access implementation processes, which will not be elaborated here.

[0373] For example, after switching to the second network device, the second terminal device can send random access information to the second network device using a random access channel (RACH) procedure or a random access channelless (RACH-less) procedure. The random access information may include a random access preamble. Optionally, the period for sending the random access resource can be at least one of the following: 10ms, 20ms, 40ms, 80ms, or 160ms.

[0374] After the second terminal device successfully connects to the second network device, it can establish a communication connection with the second network device. Then, the first terminal device can send a ninth message to the second network device through the second terminal device. The second network device can then receive the ninth message. This ninth message can be used to indicate that the first terminal device has received the second message. For example, the ninth message could be an RRC reconfiguration complete message. In this case, the RRC reconfiguration complete message can be used to indicate that the first terminal device has received the RRC reconfiguration information.

[0375] After receiving the ninth information, the second network device can send a UE context release message to the first network device. This context release message can instruct the release of the original context information of the first terminal device. Then, after receiving the context release message, the first network device can release the original context information of the first terminal device according to the context release message, such as releasing the connection or session maintained between the first network device and the first terminal device. Optionally, the context release message can be used to notify the first network device that the handover is complete. In this way, after receiving the context release message, the first network device can release the original context information of the first terminal device according to the context release message. Then, the first terminal device can transmit data with the second network device through the second terminal device.

[0376] In another possible implementation, if the first terminal device is in a scenario where non-directly connected paths and directly connected paths converge (which can be understood as the first terminal device transmitting data with the second network device via the second terminal device, or directly with the second network device), then the first terminal device can initiate random access to the second network device based on the received second information, that is, send random access information to the second network device to request access to the cell of the second network device. After receiving the random access information, the second network device can then send random access response information to the first terminal device. It is understood that the specific implementation of random access between the first terminal device and the second network device can refer to the existing random access implementation process, which will not be elaborated here. Furthermore, the second terminal device can also initiate random access to the second network device based on the received second information, that is, send random access information to the second network device to request access to the cell of the second network device. After receiving the random access information, the second network device can then send random access response information to the second terminal device.

[0377] In this embodiment, after the first terminal device and the second terminal device successfully access the second network device, the first terminal device can directly send the ninth information to the second network device, and / or can send the ninth information to the second network device through the second terminal device. The ninth information can be used to indicate that the first terminal device has received the second information. For example, the ninth information can be RRC reconfiguration completion information. Thus, the RRC reconfiguration completion information can be used to indicate that the first terminal device has received the RRC reconfiguration information. For instance, the meaning of "and" here can be that the first terminal device sends a portion of data to the second network device through a direct connection path and a non-direct connection path, such as sending a portion of the bit data corresponding to the ninth information to the second network device through a direct connection path and another portion of the bit data corresponding to the ninth information to the second network device through a non-direct connection path.

[0378] Optionally, after receiving the ninth information, the second network device may send context release information to the first network device. The context release information may instruct the release of the original context information of the first terminal device. Then, after receiving the context release information, the first network device may release the original context information of the first terminal device according to the context release information, such as releasing the connection or session maintained between the first network device and the first terminal device. Optionally, the context release information may be used to notify the first network device that the handover is complete, so that after receiving the context release information, the first network device may release the original context information of the first terminal device according to the context release information. Then, the first terminal device may directly transmit data with the second network device, and / or may transmit data with the second network device through the second terminal device. For example, the meaning of "and" here may refer to the first terminal device transmitting a portion of data with the second network device through a direct path and a non-direct path. For example, taking the transmission of first data between the first terminal device and the second network device as an example, the first terminal device transmits a portion of the first data with the second network device through a direct path, and the first terminal device transmits another portion of the first data with the second network device through a non-direct path.

[0379] As can be seen from S401 to S404 above, by sending the first information to the first network device, the first network device can determine in a timely and effective manner, based on the first information, whether the first terminal device and the second terminal device are switching from the first network device to the second network device in the form of a cooperative group. This helps to enable the first terminal device and the second terminal device to switch from the first network device to the second network device as a whole, thereby achieving the switch from the first network device to the second network device as a whole while maintaining the cooperative relationship between the first terminal device and the second terminal device, without having to release and re-establish the cooperative relationship between the first terminal device and the second terminal device before and after the switch. This helps to effectively reduce (or save) signaling overhead and can reduce the handover latency.

[0380] Based on the above Figure 4 The implementation scheme of the communication method shown is as follows: Figure 5 The specific example shown above is related to the above. Figure 4 The communication method shown is described in detail. Figure 5 In the specific example shown, the first terminal device is a remote UE, the second terminal device is a relay UE, the first network device is the source base station, the second network device is base station 1, the second information is RRC reconfiguration information, the fifth information is handover request information, the sixth information is handover request response information, the ninth information is RRC reconfiguration completion information, and the tenth information is RRC reconfiguration completion information. This is understandable. Figure 5The circles shown in the diagram can indicate that communication between the remote UE and the source base station needs to go through the relay UE, or they can indicate that communication between the remote UE and base station 1 needs to go through the relay UE.

[0381] Figure 5 This is a flowchart illustrating another communication method provided in an embodiment of this application. Figure 5 As shown, the specific process of this method may include:

[0382] S501: The remote UE sends the first information to the source base station. Correspondingly, the source base station receives the first information.

[0383] If there is a direct path and a non-direct path between the remote UE and the source base station, the remote UE can directly send the first information to the source base station, and / or can send the first information to the source base station through a relay UE. For example, "and" here could mean that the remote UE sends a portion of the data to the source base station through both the direct path and the non-direct path. For instance, it could send a portion of the bit data corresponding to the first information to the source base station through the direct path, and another portion of the bit data corresponding to the first information to the source base station through the non-direct path.

[0384] If there is no direct path between the remote UE and the source base station, but only a non-direct path, the remote UE will send the first information to the source base station through the relay UE.

[0385] Understandable. Figure 5 In S501, the solid black arrow indicates a non-directly connected path, and the dashed arrow indicates a directly connected path.

[0386] S502: The relay UE sends the first information to the source base station. Correspondingly, the source base station receives the first information.

[0387] For details regarding the first information mentioned in S501 and S502, please refer to the description of the first information in S401 above, which will not be repeated here.

[0388] Understandably, at least one of S501 and S502 can be executed, for example, S501 can be executed, or S502 can be executed, or both S501 and S502 can be executed. When both S501 and S502 are executed, the first information sent by the relay UE to the source base station can be the same as or different from the first information sent by the remote UE to the source base station. It should be understood that "different" here can mean that the first information sent by the relay UE is partially different from the first information sent by the remote UE, partially the same, or completely different from the first information sent by the remote UE.

[0389] S503: Based on the received first information, the source base station determines that the remote UE and relay UE will switch from the source base station to base station 1 in the form of a cooperative group.

[0390] The implementation process of S503 can refer to the relevant implementation of S402 above regarding determining that the first terminal device and the second terminal device switch from the first network device to the second network device in the form of a cooperative group, which will not be repeated here.

[0391] S504: The source base station sends a handover request to base station 1. Accordingly, base station 1 receives the handover request.

[0392] The implementation process of S504 can refer to the relevant implementation of S402 above regarding the first network device sending the fifth information to the second network device, and will not be repeated here.

[0393] S505: Base station 1 performs access control.

[0394] The implementation process of S505 can be referred to the relevant introduction on access control in S403 above, and will not be repeated here.

[0395] S506: Base station 1 sends a handover request response to the source base station. Correspondingly, the source base station receives the handover request response.

[0396] The implementation process of S506 can be referred to the relevant introduction of the second network device sending the sixth information to the first network device in S403 above, and will not be repeated here.

[0397] S507: The source base station sends RRC reconfiguration information to the relay UE. Correspondingly, the relay UE receives the RRC reconfiguration information.

[0398] For details regarding the RRC reconfiguration information mentioned in S507, please refer to the description of the second information sent by the first network device to the second terminal device in S404 above, which will not be repeated here.

[0399] S508: The source base station sends RRC reconfiguration information to the remote UE. Correspondingly, the remote UE receives the RRC reconfiguration information.

[0400] For details regarding the RRC reconfiguration information mentioned in S508, please refer to the description of the second information sent by the first network device to the first terminal device in S404 above, which will not be repeated here.

[0401] If there is both a direct path and a non-direct path between the remote UE and the source base station, the source base station can directly send the RRC reconfiguration information to the remote UE, and / or can send the RRC reconfiguration information to the remote UE through a relay UE. For example, "and" here could mean that the source base station sends a portion of the data to the remote UE through both the direct and non-direct paths. For instance, it could send a portion of the bit data corresponding to the RRC reconfiguration information to the remote UE through the direct path, and another portion through the non-direct path.

[0402] If there is no direct path between the remote UE and the source base station, but only a non-direct path, the source base station will send the RRC reconfiguration information to the remote UE through the relay UE.

[0403] Understandable. Figure 5 In S508, the solid black arrow indicates a non-direct connection path, and the dashed arrow indicates a direct connection path.

[0404] S509: The source base station sends SN state transition information to base station 1. Accordingly, base station 1 receives the SN state transition information.

[0405] For details regarding the SN state transition information mentioned in S509, please refer to the description of SN state transition information above, which will not be repeated here.

[0406] S510: The relay UE sends random access information to base station 1. Correspondingly, base station 1 receives the random access information.

[0407] The implementation process of S510 can be referred to in the above description of the implementation process of the second terminal device initiating random access to the second network device, and will not be repeated here.

[0408] In this embodiment of the application, after receiving random access information from relay UE, base station 1 can send random access response information to relay UE.

[0409] S511: The remote UE sends random access information to base station 1. Accordingly, base station 1 receives the random access information.

[0410] S511 above is an optional step.

[0411] If the remote UE is in a non-direct path scenario (meaning the remote UE needs to transmit data with base station 1 through a relay UE), then the relay UE sends random access information to base station 1. This means S511 is not executed, but S510 is executed instead. If the remote UE is in a scenario combining non-direct and direct paths (meaning the remote UE can transmit data with base station 1 through a relay UE or directly with base station 1), then both the remote UE and the relay UE can send random access information to base station 1. This means both S511 and S510 are executed.

[0412] The implementation process of S511 can be referred to in the above description of the implementation process of the first terminal device initiating random access to the second network device, and will not be repeated here.

[0413] In this embodiment of the application, after receiving random access information from the remote UE, the base station 1 can send random access response information to the remote UE.

[0414] S512: The remote UE sends an RRC reconfiguration completion message to base station 1. Correspondingly, base station 1 receives the RRC reconfiguration completion message.

[0415] For details regarding the RRC reconfiguration completion information mentioned in S512, please refer to the description of RRC reconfiguration completion information above, which will not be repeated here.

[0416] If the remote UE is in a non-direct path scenario (which can be understood as the remote UE needing to transmit data with base station 1 through relay UE), then the remote UE can send the RRC reconfiguration completion information to base station 1 through relay UE.

[0417] If the remote UE is in a scenario where both a non-directly connected path and a directly connected path are combined (meaning the remote UE can transmit data with base station 1 via a relay UE or directly with base station 1), then the remote UE can directly send the RRC reconfiguration completion information to base station 1, and / or can send the RRC reconfiguration completion information to base station 1 via a relay UE. For example, "and" here could mean that the remote UE sends a portion of the data to base station 1 via both the directly connected path and the non-directly connected path. For instance, it could send a portion of the bit data corresponding to the RRC reconfiguration completion information to base station 1 via the directly connected path, and another portion via the non-directly connected path.

[0418] Understandable. Figure 5 In S512, the solid black arrow indicates a non-directly connected path, and the dashed arrow indicates a directly connected path.

[0419] S513: Base station 1 sends context release information to the source base station. Correspondingly, the source base station receives the context release information.

[0420] For details regarding the context release information mentioned in S513, please refer to the description of context release information above, which will not be repeated here.

[0421] S514: The remote UE transmits data with base station 1 through the relay UE.

[0422] S514 above is an optional step.

[0423] S515: The remote UE transmits data with base station 1.

[0424] S515 above is an optional step.

[0425] If the remote UE is in a non-direct path scenario (meaning the remote UE needs to transmit data with base station 1 through a relay UE), then the remote UE transmits data with base station 1 through the relay UE, meaning S515 will not be executed. If the remote UE is in a scenario combining non-direct and direct paths (meaning the remote UE can transmit data with base station 1 through a relay UE or directly with base station 1), then the remote UE can transmit data directly with base station 1, and / or can transmit data with base station 1 through a relay UE. In other words, in a scenario combining non-direct and direct paths, S515, S514, or both can be executed. For example, the meaning of "and" here could be that the remote UE transmits a portion of data with base station 1 through both the direct and non-direct paths. For instance, consider the remote UE transmitting the first data to base station 1. The remote UE transmits a portion of the first data to base station 1 via a direct connection path, while the remote UE transmits another portion of the first data to base station 1 via a non-direct connection path.

[0426] It is understood that, in order to achieve the functions in the above embodiments, the first terminal device, the second terminal device, the first network device, and the second network device include hardware structures and / or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and method steps of the various examples described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0427] Figure 6 and Figure 7 The diagram illustrates the possible structures of communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of the first terminal device, the second terminal device, the first network device, or the second network device in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. For example, the communication device may be as follows: Figure 1 or Figure 2 or Figure 3a or Figure 3b The terminal device shown can also be as follows: Figure 1 or Figure 2 or Figure 3a or Figure 3b The network device shown can also be a module (such as a chip) applied to terminal devices or network devices.

[0428] Figure 6 The communication device 600 shown includes a transceiver unit 610 (or may be referred to as a communication module, transceiver module, or communication module for sending and receiving data). Optionally, Figure 6 The communication device 600 shown may further include a processing unit 620 (or a processing module). The communication device 900 can be used to implement the above. Figure 4 or Figure 5 The method embodiments shown illustrate the functions of the first terminal device, the second terminal device, the first network device, and the second network device. For example, the transceiver unit 610 can perform the receiving and sending actions performed by the first terminal device, the second terminal device, the first network device, or the second network device in the above method embodiments. The processing unit 620 can perform other actions besides the sending and receiving actions performed by the first terminal device, the second terminal device, the first network device, or the second network device in the above method embodiments.

[0429] When the communication device 600 is used to achieve the above Figure 4 or Figure 5 In the method embodiment shown, when the first terminal device or the second terminal device functions as follows: The transceiver unit 610 is used to send first information to the first network device. The first information is used by the first network device to determine that the first terminal device and the second terminal device are switching from the first network device to the second network device in a cooperative group. Switching from the first network device to the second network device in a cooperative group means that before the switch, the first terminal device communicated with the first network device through the second terminal device, and after the switch, the first terminal device communicates with the second network device through the second terminal device. The transceiver unit 610 is also used to receive second information from the first network device. The second information is used to instruct the first terminal device and the second terminal device to switch from the first network device to the second network device in a cooperative group. The processing unit 620 is used to perform corresponding processing operations, such as calling the transceiver unit 610 to execute the above-described... Figure 4 or Figure 5 The sending and receiving actions that the first terminal device or the second terminal device needs to perform in the method embodiment shown can be used to generate first information, etc.

[0430] Optionally, when the communication device 600 is used to implement the above... Figure 4 or Figure 5In the illustrated method embodiment, the functions of the first terminal device and the second terminal device are as follows: The transceiver unit 610 in the first terminal device can be used to send first information to the first network device, and the transceiver unit 610 in the second terminal device can also be used to send first information to the first network device. The first information is used by the first network device to determine that the first terminal device and the second terminal device are switching from the first network device to the second network device in a cooperative group. Switching from the first network device to the second network device in a cooperative group means that before the switch, the first terminal device communicated with the first network device through the second terminal device, and after the switch, the first terminal device communicates with the second network device through the second terminal device. The transceiver unit 610 in the first terminal device can also be used to receive second information from the first network device for the first terminal device, and the transceiver unit 610 in the second terminal device can also be used to receive second information from the first network device for the second terminal device. The second information is used to instruct the first terminal device and the second terminal device to switch from the first network device to the second network device in a cooperative group. The processing unit 620 in the first terminal device is used to perform corresponding processing operations, such as calling the transceiver unit 610 to execute the above-described... Figure 4 or Figure 5 The transmitting and receiving actions that the first terminal device needs to perform in the method embodiment shown can also be used to generate the first information that the first terminal device needs to send. The processing unit 620 in the second terminal device is used to perform corresponding processing operations, such as calling the transmitting and receiving unit 610 to perform the above-mentioned actions. Figure 4 or Figure 5 The sending and receiving actions that the second terminal device needs to perform in the method embodiment shown can be used to generate the first information that the second terminal device needs to send, etc.

[0431] When the communication device 600 is used to achieve the above Figure 4 or Figure 5In the illustrated method embodiment, the first network device functions as follows: A transceiver unit 610 is configured to receive first information from a first terminal device and / or a second terminal device. The first information determines that the first terminal device and the second terminal device are switching from the first network device to the second network device in a cooperative group. Switching from the first network device to the second network device in a cooperative group indicates that before the switch, the first terminal device communicated with the first network device through the second terminal device, and after the switch, the first terminal device communicates with the second network device through the second terminal device. The transceiver unit 610 is also configured to send fifth information to the second network device. The fifth information requests that the first terminal device and the second terminal device be switched from the first network device to the second network device in a cooperative group. The transceiver unit 610 is also configured to receive sixth information from the second network device. The sixth information includes configuration information required for the first terminal device to communicate under the second network device and configuration information required for the second terminal device to communicate under the second network device. The transceiver unit 610 is also configured to send second information to the first terminal device and / or the second terminal device. The second information is used to instruct the first terminal device and the second terminal device to switch from the first network device to the second network device in the form of a cooperative group. The processing unit 620 is used to perform corresponding processing operations, such as calling the transceiver unit 610 to execute the above-mentioned... Figure 4 or Figure 5 The sending and receiving actions that the first network device needs to perform in the method embodiment shown may also be used to determine whether the first terminal device and the second terminal device switch from the first network device to the second network device in the form of a cooperative group.

[0432] When the communication device 600 is used to achieve the above Figure 4 or Figure 5 In the illustrated method embodiment, the function of the second network device is as follows: A transceiver unit 610 is used to receive fifth information from the first network device. This fifth information requests a switch between the first and second terminal devices in a cooperative group from the first network device to the second network device. Switching from the first to the second network device in a cooperative group means that before the switch, the first terminal device communicated with the first network device through the second terminal device, and after the switch, the first terminal device communicates with the second network device through the second terminal device. The transceiver unit 610 is also used to send sixth information to the first network device. This sixth information includes configuration information required for the first terminal device to communicate under the second network device and configuration information required for the second terminal device to communicate under the second network device. A processing unit 620 is used to perform corresponding processing operations, such as calling the transceiver unit 610 to execute the above-described... Figure 4 or Figure 5The sending and receiving actions that the second network device needs to perform in the method embodiment shown may also be used to generate sixth information, etc.

[0433] For a more detailed description of the processing unit 620 and the transceiver unit 610, please refer to the above. Figure 4 or Figure 5 The relevant descriptions in the method embodiments shown will not be repeated here.

[0434] It should be understood that the transceiver unit 610 in the embodiments of this application can be implemented by an interface circuit or interface circuit-related circuit components, and the processing unit 620 can be implemented by a processor or processor-related circuit components.

[0435] It should be noted that the module division in the embodiments of this application is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods. Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, exist as separate physical entities, or have two or more units integrated into one unit. The integrated units described above can be implemented in hardware or as software functional units.

[0436] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, or a server, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0437] Figure 7 The communication device 700 shown includes at least one processor 720 and interface circuitry 710. The at least one processor 720 and interface circuitry 710 may be coupled to each other. It is understood that interface circuitry 710 may be a transceiver or an input / output interface. Optionally, the communication device 700 may also include a memory 730. Memory 730 is used to store instructions executed by at least one processor 720, or to store input data required for at least one processor 720 to execute instructions, or to store data generated after at least one processor 720 executes instructions.

[0438] When the communication device 700 is used to achieve the above Figure 4 or Figure 5 In the method embodiment shown, at least one processor 720 is used to implement the functions of the processing unit 620, and the interface circuit 710 is used to implement the functions of the transceiver unit 610.

[0439] For example, consider a terminal device (e.g., the first terminal device) as the UE and a network device (e.g., the first network device) as the base station. When the aforementioned communication device is a chip applied to the UE, the UE chip implements the functions corresponding to the UE in the above method embodiments. For example, when the UE chip receives information from the base station, it can be understood that the information is first received by other modules in the UE (such as a radio frequency module or antenna), and then sent to the UE chip by these modules. When the UE chip sends information to the base station, it can be understood that the information is first sent to other modules in the UE (such as a radio frequency module or antenna), and then sent to the base station by these modules.

[0440] When the aforementioned communication device is a chip applied to a base station, the base station chip implements the functions corresponding to the base station in the above method embodiments. For example, when the base station chip receives information from the UE, it can be understood that the information is first received by other modules in the base station (such as an RF module or antenna), and then sent to the base station chip by these modules. When the base station chip sends information to the UE, it can be understood that the information is sent down to other modules in the base station (such as an RF module or antenna), and then sent to the UE by these modules.

[0441] In this application, entity A sends information to entity B, either directly or indirectly through other entities. Similarly, entity B receives information from entity A, either directly or indirectly through other entities. Entities A and B can be terminal devices or network devices, or modules within those devices. For example, consider terminal devices and network devices. Information transmission and reception can be between a terminal device and a network device, such as between a UE and a base station. Information transmission and reception can also be between two base stations, such as between a CU and a DU. Furthermore, information transmission and reception can be between different modules within a single device, such as between a UE chip and other UE modules, or between a base station chip and other modules within that base station.

[0442] Based on the same concept, embodiments of this application also provide a possible communication system. This communication system may include one or more of a first terminal device, a second terminal device, a first network device, or a second network device. The first terminal device can be used to implement the technical solutions related to the first terminal device in the above embodiments, the second terminal device can be used to implement the technical solutions related to the second terminal device in the above embodiments, the first network device can be used to implement the technical solutions related to the first network device in the above embodiments, and the second network device can be used to implement the technical solutions related to the second network device in the above embodiments.

[0443] Based on the same concept, this application also provides a computer program product, which includes a computer program or instructions that, when run on a communication device (or computer), cause the communication device (or computer) to perform the methods provided in the above embodiments.

[0444] Based on the same concept, embodiments of this application also provide a computer-readable storage medium storing a computer program or instructions that, when executed by a communication device (or computer), cause the communication device (or computer) to perform the methods provided in the above embodiments.

[0445] The storage medium can be any available medium that a computer can access. For example, but not limited to, a computer-readable medium can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0446] Based on the same concept, embodiments of this application also provide a chip, which may include at least one processor and may also include a memory (or the chip may be coupled to the memory), wherein the at least one processor executes program instructions in the memory to cause the chip to perform the methods provided in the above embodiments. Here, "coupling" refers to two components being directly or indirectly connected to each other, such as coupling referring to an electrical connection between two components.

[0447] Based on the same concept, embodiments of this application also provide a chip system, which includes at least one processor for supporting a computer device in implementing the functions involved in the terminal device or network device in the above embodiments. In one possible implementation, the chip system further includes a memory for storing necessary programs and data of the computer device. This chip system may be composed of chips or may include chips and other discrete components.

[0448] It is understood that the processor in the embodiments of this application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor may be a microprocessor or any conventional processor.

[0449] The method steps in the embodiments of this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, compact disc read-only memory (CD-ROM), or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Furthermore, the ASIC can reside in a first terminal device, a second terminal device, a first network device, or a second network device. Alternatively, the processor and storage medium can exist as discrete components in the first terminal device, the second terminal device, the first network device, or the second network device.

[0450] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. A computer program is a set of instructions that directs each step of an action of an electronic computer or other device with message processing capabilities. It is typically written in a programming language and runs on a target architecture. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed, in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium can be volatile or non-volatile, or it can include both types of storage media.

[0451] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0452] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates an "or" relationship between the preceding and following related objects; in the formulas of this application, the character " / " indicates a "division" relationship between the preceding and following related objects.

[0453] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A communication method, characterized in that, The method, applied to a first terminal device and / or a second terminal device, or applied to a chip in the first terminal device and / or a chip in the second terminal device, comprises: Send first information to the first network device. The first information is used by the first network device to determine that the first terminal device and the second terminal device are switching from the first network device to the second network device in the form of a cooperative group. The switching from the first network device to the second network device in the form of a cooperative group means that before the switch, the first terminal device communicates with the first network device through the second terminal device, and after the switch, the first terminal device communicates with the second network device through the second terminal device. The system receives second information from the first network device, the second information being used to instruct the first terminal device and the second terminal device to switch from the first network device to the second network device in the form of a cooperative group.

2. The method as described in claim 1, characterized in that, Before sending the first information to the first network device, the method further includes: The switching mode of the first terminal device and the second terminal device is determined to be a cooperative group switching mode. The cooperative group switching mode means that the first terminal device and the second terminal device switch from the first network device to the target network device in the form of a cooperative group. The target network device includes the second network device.

3. The method as described in claim 2, characterized in that, Determining the handover mode of the first terminal device and the second terminal device as a cooperative group handover mode includes: Receive third information from the first network device, the third information being used to indicate that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode; Based on the third information, the switching mode of the first terminal device and the second terminal device is determined to be the cooperative group switching mode.

4. The method as described in claim 2, characterized in that, The switching mode of the first terminal device and the second terminal device is determined to be the cooperative group switching mode if at least one of the following conditions is met: The crosslink signal quality between the first terminal device and the second terminal device is greater than or equal to a first threshold. The distance between the first terminal device and the second terminal device is less than or equal to a distance threshold, and the distance is determined based on the first location information of the first terminal device and the second location information of the second terminal device. The path loss between the first terminal device and the second terminal device is less than or equal to the loss threshold. The identifier of the first serving cell of the first terminal device is the same as the identifier of the second serving cell of the second terminal device; The identifier of the first service beam of the first terminal device is the same as the identifier of the second service beam of the second terminal device; The matching degree between the first visible information of the first terminal device to the first network device and the second visible information of the second terminal device to the first network device is greater than or equal to the second threshold. The matching degree between the third visible information of the first terminal device to the second network device and the fourth visible information of the second terminal device to the second network device is greater than or equal to the third threshold. The distance between the movement trajectory of the first terminal device and the movement trajectory of the second terminal device is less than or equal to a fourth threshold; the movement trajectory of the first terminal device is determined based on the first movement trajectory information of the first terminal device; and the movement trajectory of the second terminal device is determined based on the second movement trajectory information of the second terminal device; or, The difference between the attitude angle of the first terminal device and the attitude angle of the second terminal device is less than or equal to a fifth threshold. The attitude angle of the first terminal device is determined based on the first attitude information of the first terminal device, and the attitude angle of the second terminal device is determined based on the second attitude information of the second terminal device.

5. The method according to any one of claims 2-4, characterized in that, The method further includes: Send a fourth message to the first network device, the fourth message being used by the first network device to determine that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode.

6. The method as described in claim 5, characterized in that, The fourth piece of information includes at least one of the following: The switching mode between the first terminal device and the second terminal device is the cooperative group switching mode; The crosslink signal quality between the first terminal device and the second terminal device; The first location information of the first terminal device; The second location information of the second terminal location; Path loss between the first terminal device and the second terminal device; The identifier of the first serving cell of the first terminal device; The identifier of the first service beam of the first terminal device; The identifier of the second serving cell of the second terminal device; The identifier of the second service beam of the second terminal device; The first visible information of the first terminal device to the first network device; The second terminal device has second visible information about the first network device; The third visible information of the first terminal device to the second network device; The second terminal device has fourth visible information about the second network device; The first movement trajectory information of the first terminal device; The second movement trajectory information of the second terminal device; The first posture information of the first terminal device; or, The second attitude information of the second terminal device.

7. The method according to any one of claims 1-6, characterized in that, The first information includes at least one of the following: first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality, or sixth signal quality; Wherein, the first signal quality is obtained by the first terminal device measuring the signal of the first network device, the second signal quality is obtained by the first terminal device measuring the signal of the second network device, the third signal quality is obtained by the second terminal device measuring the signal of the first network device, the fourth signal quality is obtained by the second terminal device measuring the signal of the second network device, the fifth signal quality represents the sidelink signal quality between the first terminal device and the second terminal device, and the sixth signal quality represents the sidelink signal quality between the first terminal device and the third terminal device. The second terminal device and the third terminal device are included in a plurality of candidate terminal devices for providing relay services.

8. The method as described in claim 7, characterized in that, The first information is sent to the first network device if at least one of the following conditions is met: The difference between the fourth signal quality and the third signal quality is greater than or equal to the sixth threshold. The difference between the fourth signal quality and the maximum signal quality among the first signal quality and the second signal quality is greater than or equal to the seventh threshold. The quality of the fifth signal is greater than or equal to the eighth threshold; The difference between the quality of the fifth signal and the quality of the sixth signal is greater than or equal to the ninth threshold. The difference between the fourth signal quality and the first signal quality is greater than or equal to the tenth threshold. The difference between the fourth signal quality and the second signal quality is greater than or equal to the eleventh threshold; or, The difference between the second signal quality and the first signal quality is greater than or equal to the twelfth threshold.

9. The method according to any one of claims 1-8, characterized in that, When the first terminal device receives the second information, the second information includes at least one of the following: relay configuration information, end-to-end radio bearer information, or access configuration information; The relay configuration information includes at least one of the following: the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, or PC5 relay radio link control (RLC) channel configuration information; The access configuration information includes at least one of the following: the cell identifier of the second network device, or access information used by the first terminal device to access the second network device.

10. The method according to any one of claims 1-8, characterized in that, When the second terminal device receives the second information, the second information includes at least one of the following: relay configuration information, bearer mapping configuration information, or access configuration information; The relay configuration information includes at least one of the following: the local identifier of the second terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, PC5 relay RLC channel configuration information, or air interface relay RLC channel configuration information. The access configuration information includes at least one of the following: the cell identifier of the second network device, or access information used by the second terminal device to access the second network device.

11. A communication method, characterized in that, The method, applied to a first network device or a chip in the first network device, includes: Receive first information from a first terminal device and / or a second terminal device, the first information being used to determine that the first terminal device and the second terminal device switch from the first network device to the second network device in the form of a cooperative group, wherein the switch from the first network device to the second network device in the form of a cooperative group indicates that before the switch, the first terminal device communicated with the first network device through the second terminal device, and after the switch, the first terminal device communicated with the second network device through the second terminal device. Send a fifth message to the second network device, the fifth message being used to request that the first terminal device and the second terminal device be switched from the first network device to the second network device in the form of a cooperative group; Receive sixth information from the second network device, the sixth information including configuration information required for the first terminal device to communicate under the second network device and configuration information required for the second terminal device to communicate under the second network device; Send a second message to the first terminal device and / or the second terminal device, the second message being used to instruct the first terminal device and the second terminal device to switch from the first network device to the second network device in the form of a cooperative group.

12. The method as described in claim 11, characterized in that, The method further includes: The system receives fourth information from the first terminal device and / or the second terminal device, the fourth information being used to determine that the switching mode of the first terminal device and the second terminal device is a cooperative group switching mode, the cooperative group switching mode indicating that the first terminal device and the second terminal device switch from the first network device to the target network device in the form of a cooperative group, the target network device including the second network device.

13. The method as described in claim 12, characterized in that, The fourth piece of information includes at least one of the following: The switching mode between the first terminal device and the second terminal device is the cooperative group switching mode; The crosslink signal quality between the first terminal device and the second terminal device; The first location information of the first terminal device; The second location information of the second terminal location; Path loss between the first terminal device and the second terminal device; The identifier of the first serving cell of the first terminal device; The identifier of the first service beam of the first terminal device; The identifier of the second serving cell of the second terminal device; The identifier of the second service beam of the second terminal device; The first visible information of the first terminal device to the first network device; The second terminal device has second visible information about the first network device; The third visible information of the first terminal device to the second network device; The second terminal device has fourth visible information about the second network device; The first movement trajectory information of the first terminal device; The second movement trajectory information of the second terminal device; The first posture information of the first terminal device; or, The second attitude information of the second terminal device.

14. The method as described in claim 13, characterized in that, The method further includes: If the fourth information includes the switching mode of the first terminal device and the second terminal device as the collaboration group switching mode, then based on the fourth information, the switching mode of the first terminal device and the second terminal device is determined to be the collaboration group switching mode.

15. The method as described in claim 13, characterized in that, The method further includes: The switching mode of the first terminal device and the second terminal device is determined to be the cooperative group switching mode if at least one of the following conditions is met: The quality of the side link signal is greater than or equal to the first threshold. The distance between the first terminal device and the second terminal device is less than or equal to a distance threshold, and the distance is determined based on the first location information and the second location information; The path loss is less than or equal to the loss threshold; The identifier of the first serving cell is the same as the identifier of the second serving cell; The identifier of the first service beam is the same as the identifier of the second service beam; The matching degree between the first visible information and the second visible information is greater than or equal to the second threshold; The matching degree between the third visible information and the fourth visible information of the second terminal device is greater than or equal to the third threshold. The distance between the movement trajectory of the first terminal device and the movement trajectory of the second terminal device is less than or equal to a fourth threshold, the movement trajectory of the first terminal device is determined based on the first movement trajectory information, and the movement trajectory of the second terminal device is determined based on the second movement trajectory information; or, The difference between the attitude angle of the first terminal device and the attitude angle of the second terminal device is less than or equal to a fifth threshold. The attitude angle of the first terminal device is determined based on the first attitude information, and the attitude angle of the second terminal device is determined based on the second attitude information.

16. The method according to any one of claims 12-15, characterized in that, The method further includes: Send a third message to the first terminal device and / or the second terminal device, the third message being used to indicate that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode.

17. The method according to any one of claims 12-16, characterized in that, The method further includes: A seventh message is sent to the second network device, the seventh message indicating that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode.

18. The method according to any one of claims 11-17, characterized in that, The first information includes at least one of the following: first signal quality, second signal quality, third signal quality, fourth signal quality, fifth signal quality, or sixth signal quality; Wherein, the first signal quality is obtained by the first terminal device measuring the signal of the first network device, the second signal quality is obtained by the first terminal device measuring the signal of the second network device, the third signal quality is obtained by the second terminal device measuring the signal of the first network device, the fourth signal quality is obtained by the second terminal device measuring the signal of the second network device, the fifth signal quality represents the sidelink signal quality between the first terminal device and the second terminal device, and the sixth signal quality represents the sidelink signal quality between the first terminal device and the third terminal device. The second terminal device and the third terminal device are included in a plurality of candidate terminal devices for providing relay services.

19. The method as described in claim 18, characterized in that, The method further includes: The first terminal device and the second terminal device are determined to be switching from the first network device to the second network device in the form of a cooperative group if at least one of the following conditions is met: The difference between the fourth signal quality and the third signal quality is greater than or equal to the sixth threshold. The difference between the fourth signal quality and the maximum signal quality among the first signal quality and the second signal quality is greater than or equal to the seventh threshold. The quality of the fifth signal is greater than or equal to the eighth threshold; The difference between the quality of the fifth signal and the quality of the sixth signal is greater than or equal to the ninth threshold. The difference between the fourth signal quality and the first signal quality is greater than or equal to the tenth threshold. The difference between the fourth signal quality and the second signal quality is greater than or equal to the eleventh threshold; or, The difference between the second signal quality and the first signal quality is greater than or equal to the twelfth threshold.

20. The method according to any one of claims 11-19, characterized in that, When the second information is sent to the first terminal device, the second information includes at least one of the following: relay configuration information, end-to-end radio bearer information, or access configuration information; The relay configuration information includes at least one of the following: the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, or PC5 relay RLC channel configuration information; The access configuration information includes at least one of the following: the cell identifier of the second network device, or access information used by the first terminal device to access the second network device.

21. The method according to any one of claims 11-19, characterized in that, When the second information is sent to the second terminal device, the second information includes at least one of the following: relay configuration information, bearer mapping configuration information, or access configuration information; The relay configuration information includes at least one of the following: the local identifier of the second terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, PC5 relay RLC channel configuration information, or air interface relay RLC channel configuration information. The access configuration information includes at least one of the following: the cell identifier of the second network device, or access information used by the second terminal device to access the second network device.

22. A communication method, characterized in that, The method, applied to a second network device or a chip in the second network device, includes: The system receives a fifth message from a first network device, which requests that a first terminal device and a second terminal device be switched from the first network device to the second network device in the form of a cooperative group. The switch from the first network device to the second network device in the form of a cooperative group indicates that before the switch, the first terminal device communicates with the first network device through the second terminal device, and after the switch, the first terminal device communicates with the second network device through the second terminal device. Send a sixth message to the first network device, the sixth message including configuration information required for the first terminal device to communicate under the second network device and configuration information required for the second terminal device to communicate under the second network device.

23. The method as described in claim 22, characterized in that, The method further includes: The system receives a seventh message from the first network device, the seventh message indicating that the switching mode of the first terminal device and the second terminal device is the cooperative group switching mode.

24. The method as described in claim 22 or 23, characterized in that, The configuration information required for the first terminal device to communicate under the second network device includes at least one of the following: relay configuration information, end-to-end wireless bearer information, or access configuration information; The relay configuration information includes at least one of the following: the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, or PC5 relay RLC channel configuration information; The access configuration information includes at least one of the following: the cell identifier of the second network device, or access information used by the first terminal device to access the second network device.

25. The method according to any one of claims 22-24, characterized in that, The configuration information required for the second terminal device to communicate under the second network device includes at least one of the following: relay configuration information, bearer mapping configuration information, or access configuration information; The relay configuration information includes at least one of the following: the local identifier of the second terminal device under the second network device, the layer 2 identifier of the second terminal device under the second network device, the local identifier of the first terminal device under the second network device, the layer 2 identifier of the first terminal device under the second network device, PC5 relay RLC channel configuration information, or air interface relay RLC channel configuration information. The access configuration information includes at least one of the following: the cell identifier of the second network device, or access information used by the second terminal device to access the second network device.

26. The method according to any one of claims 1-25, characterized in that, The first network device or the second network device is a non-terrestrial network (NTN) device.

27. A communication device, characterized in that, It includes modules or units for performing the method as described in any one of claims 1-10, or modules or units for performing the method as described in any one of claims 11-21, or modules or units for performing the method as described in any one of claims 22-25, or modules or units for performing the method as described in claim 26.

28. A communication device, characterized in that, Includes at least one processor and interface circuitry; The interface circuit is used to receive signals from other communication devices and transmit them to the at least one processor, or to send signals from the at least one processor to other communication devices. The at least one processor is configured to implement the method of any one of claims 1-10, or the method of any one of claims 11-21, or the method of any one of claims 22-25, or the method of claim 26, through logic circuits or executing code instructions.

29. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed by a communication device, cause the method as described in any one of claims 1-10, or the method as described in any one of claims 11-21, or the method as described in any one of claims 22-25, or the method as described in claim 26 to be implemented.

30. A computer program product, characterized in that, The computer program product includes a computer program or instructions that, when executed on a communication device, cause the method as described in any one of claims 1-10, or the method as described in any one of claims 11-21, or the method as described in any one of claims 22-25, or the method as described in claim 26 to be implemented.

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