EP-4738972-A1 - COMMUNICATION METHOD AND APPARATUS

Abstract

Embodiments of this application provide a communication method and apparatus, to implement compatibility between a function of cell switching triggered by lower layer signaling and a function of inter-cell multi-station transmission. The method includes: A terminal device receives indication information from a network device, where the indication information is for triggering a random access procedure; and if the network device configures first configuration information and second configuration information for the terminal device, the downlink control information includes a first field and a second field. The terminal device determines, based on a combination of the first field and the second field, information corresponding to the random access procedure.

Inventors

• FAN, BO

Assignees

• Huawei Technologies Co., Ltd.

Dates

Publication Date

20260506

Application Date

20240801

Claims (20)

1. A communication method, wherein the method comprises: receiving downlink control information, wherein the downlink control information is for triggering a random access procedure; and if a network device configures first configuration information and second configuration information for a terminal device, the downlink control information comprises a first field and a second field; and determining, based on a combination of the first field and the second field, information corresponding to the random access procedure.
2. A communication method, wherein the method comprises: sending downlink control information, wherein the downlink control is for triggering a random access procedure; and if a network device configures first configuration information and second configuration information for a terminal device, the downlink control information comprises a first field and a second field; and receiving a random access request message that is in the random access procedure and that is sent by the terminal device.
3. The method according to claim 1 or 2, wherein the first configuration information is for configuring a related parameter of cell switching triggered by lower layer signaling, and the related parameter of cell switching triggered by lower layer signaling comprises a related parameter for random access to at least one candidate cell.
4. The method according to any one of claims 1 to 3, wherein the second configuration information is for configuring a related parameter of multi-station transmission, and the related parameter of the multi-station transmission comprises two timing advance groups and two control channel groups.
5. The method according to any one of claims 1 to 4, wherein the first field indicates, in a first cell set, a cell corresponding to the random access procedure, wherein the first cell set comprises a serving cell and at least one candidate cell.
6. The method according to claim 5, wherein if a value of the first field is 0, the first field indicates the serving cell; and/or if a value of the first field is not 0, the first field indicates one of the at least one candidate cell.
7. The method according to any one of claims 1 to 6, wherein if a first condition is satisfied, the second field indicates, in a second cell set, a cell corresponding to the random access procedure, wherein the second cell set comprises a serving cell and at least one additional cell corresponding to the serving cell, and the first condition is that the network device configures at least one additional cell for the terminal device.
8. The method according to claim 7, wherein that the second cell set comprises a serving cell and at least one additional cell corresponding to the serving cell comprises that the second cell set comprises the serving cell and an additional cell that is in an active state and that corresponds to the serving cell.
9. The method according to any one of claims 1 to 6, wherein if a second condition is satisfied, the second field indicates a path loss measurement resource for the random access request message in the random access procedure, wherein the second condition is that the network device configures no additional cell for the terminal device.
10. The method according to claim 9, wherein if a value of the second field is 0, the second field indicates a first path loss measurement resource, wherein the first path loss measurement resource is a quasi-colocation QCL resource corresponding to the downlink control information; and/or if a value of the second field is 1, the second field indicates a second path loss measurement resource, wherein the second path loss measurement resource is a synchronization signal/physical broadcast channel block SSB resource indicated by the downlink control information.
11. The method according to any one of claims 1 and 3 to 10, wherein the determining, based on the combination of the first field and the second field, the information corresponding to the random access procedure comprises: if the value of the first field is not 0, determining, based on the cell indicated by the first field, the cell corresponding to the random access procedure, and ignoring the second field; or if the value of the first field is 0, determining, based on the value of the second field, the cell corresponding to the random access procedure, or determining, based on the value of the second field, the path loss measurement resource corresponding to the random access procedure.
12. A communication apparatus, wherein the communication apparatus comprises a transceiver module and a processing module, wherein the transceiver module is configured to receive downlink control information, wherein the downlink control information is for triggering a random access procedure; and if a network device configures first configuration information and second configuration information for a terminal device, the downlink control information comprises a first field and a second field; and the processing module is configured to determine, based on a combination of the first field and the second field, information corresponding to the random access procedure.
13. A communication apparatus, wherein the communication apparatus comprises a transceiver module, wherein the transceiver module is configured to send downlink control information, wherein the downlink control information is for triggering a random access procedure; and if a network device configures first configuration information and second configuration information for a terminal device, the downlink control information comprises a first field and a second field; and the transceiver module is further configured to receive a random access request message that is in the random access procedure and that is sent by the terminal device.
14. The apparatus according to claim 12 or 13, wherein the first configuration information is for configuring a related parameter of cell switching triggered by lower layer signaling, and the related parameter of cell switching triggered by lower layer signaling comprises a related parameter for random access to at least one candidate cell.
15. The apparatus according to any one of claims 12 to 14, wherein the second configuration information is for configuring a related parameter of multi-station transmission, and the related parameter of the multi-station transmission comprises two timing advance groups and two control channel groups.
16. The apparatus according to any one of claims 12 to 15, wherein the first field indicates, in a first cell set, a cell corresponding to the random access procedure, wherein the first cell set comprises a serving cell and at least one candidate cell.
17. The apparatus according to claim 16, wherein if a value of the first field is 0, the first field indicates the serving cell; and/or if a value of the first field is not 0, the first field indicates one of the at least one candidate cell.
18. The apparatus according to any one of claims 12 to 17, wherein if a first condition is satisfied, the second field indicates, in a second cell set, a cell corresponding to the random access procedure, wherein the second cell set comprises a serving cell and at least one additional cell corresponding to the serving cell, and the first condition is that the network device configures at least one additional cell for the terminal device.
19. The apparatus according to claim 18, wherein that the second cell set comprises a serving cell and at least one additional cell corresponding to the serving cell comprises that the second cell set comprises the serving cell and an additional cell that is in an active state and that corresponds to the serving cell.
20. The apparatus according to any one of claims 12 to 17, wherein if a second condition is satisfied, the second field indicates a path loss measurement resource for the random access request message in the random access procedure, wherein the second condition is that the network device configures no additional cell for the terminal device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priorities to Chinese Patent Application No. 202311019103.8, filed with the China National Intellectual Property Administration on August 11, 2023 and entitled "COMMUNICATION METHOD AND APPARATUS", and to Chinese Patent Application No. 202311442764.1, filed with the China National Intellectual Property Administration on October 31, 2023 and entitled "COMMUNICATION METHOD AND APPARATUS", both of which are incorporated by reference in their entireties. TECHNICAL FIELD This application relates to the field of communication technologies, and in particular, to a communication method and apparatus. BACKGROUND In a communication system, there are a plurality of network devices (for example, base stations) on a network side, each network device may cover an area, and the area may be referred to as a cell. A terminal device may move from one cell to another cell, that is, move from coverage of one network device to coverage of another network device. This process is referred to as cell switching, as shown in FIG. 1. After the terminal device switches to the another cell, the network device needs to indicate the terminal device to initiate a random access procedure to the cell, so that the terminal device obtains uplink timing information, for example, a timing advance (timing advance, TA), of the cell. In this way, terminal device is able to perform uplink transmission in the cell. Currently, a communication protocol proposes a function of cell switching triggered by lower layer signaling, to implement fast cell switching. In the function of cell switching triggered by lower layer signaling, the network device may configure at least one candidate cell for the terminal device. When the terminal device moves to an edge of a current serving cell, and approaches a candidate cell, the network device may send downlink control information (downlink control information, DCI) to the terminal device in advance, where a field in the DCI indicates the candidate cell, to indicate, in advance, the terminal device to initiate a random access procedure to the candidate cell, so that the terminal device obtains a timing advance of the candidate cell in advance, as shown in (1) in FIG. 2. In addition, the communication protocol further proposes a function of inter-cell multi-station transmission, so that the terminal device performs multi-station transmission by using a serving cell and at least one additional cell corresponding to the serving cell. In the function of inter-cell multi-station transmission, the network device may configure at least one additional cell for the terminal device, and send DCI to the terminal device, where a field in the DCI indicates an additional cell, to indicate the terminal device to initiate a random access procedure to the additional cell, as shown in (2) in FIG. 2. In each of the foregoing two functions, the network device indicates, by using the DCI, the cell to which the terminal device is to initiate the random access procedure. Consequently, after receiving a piece of DCI, the terminal device is unaware of whether a cell indicated by the DCI is a cell for cell switching triggered by lower layer signaling or a cell for inter-cell multi-station transmission. That is, the foregoing two functions cannot be compatible. SUMMARY Embodiments of this application provide a communication method and apparatus, to implement compatibility between a function of cell switching triggered by lower layer signaling and a function of inter-cell multi-station transmission. According to a first aspect, this application provides a communication method. The method may be performed by a terminal device, or may be performed by a component (for example, a chip) in the terminal device. This is not limited. For example, the method is performed by the terminal device. The method includes: The terminal device receives indication information from a network device, where the indication information includes a first field, and the first field indicates a cell in a first cell set, or indicates a cell in a second cell set; and sends a random access request message to the network device by using the cell indicated by the indication information. The first cell set is a cell set for cell switching triggered by lower layer signaling. In other words, an element in the first cell set is a cell for cell switching triggered by lower layer signaling. In other words, the first cell set consists of the cell for cell switching triggered by lower layer signaling. In other words, the first cell set is a cell set corresponding to a function of cell switching triggered by lower layer signaling. In other words, a cell included in the first cell set is a cell related to (or associated with) the function of cell switching triggered by lower layer signaling. In other words, the first cell set is for the function of cell switching triggered by lower layer signaling. Optionally, the cell se