EP-4742748-A1 - RANDOM ACCESS METHOD AND APPARATUS, AND DEVICE AND STORAGE MEDIUM

Abstract

The present disclosure relates to a random access method and apparatus, and a device and a storage medium. The random access method comprises: sending first information to a first network device, wherein the first information is used for the first network device to measure a timing advance (TA), and the first network device is a network device of a candidate cell; and receiving second information sent by a second network device, wherein the second information comprises a TA corresponding to the first network device, and the second network device is a network device of a serving cell. In the present disclosure, a TA of a candidate cell is sent to a terminal by means of a serving cell, such that the terminal can receive, by means of the serving cell, the TA corresponding to the candidate cell, thereby reducing a delay of cell handover, and improving the efficiency of cell handover.

Inventors

• LUO, XINGYI

Assignees

• Beijing Xiaomi Mobile Software Co., Ltd.

Dates

Publication Date

20260513

Application Date

20230706

Claims (20)

1. A random access method, performed by a terminal, comprising: sending first information to a first network device, wherein the first information is configured to determine a Timing Advance (TA), the TA is a TA corresponding to the first network device, and the first network device is a network device of a candidate cell; and receiving second information sent by a second network device, wherein the second information is configured to indicate the TA, and the second network device is a network device of a serving cell.
2. The method according to claim 1, wherein receiving the second information sent by the second network device comprises: receiving, within a first time window, the second information sent by the second network device, wherein the first time window is determined based on a first time domain position and a first duration.
3. The method according to claim 2, wherein the first duration is determined by at least one of the following manners: the first duration is determined based on a first predefined rule, wherein the first duration is predefined by the first predefined rule; the first duration is determined based on a network device configuration; or the first duration is determined based on a second duration and a third duration, wherein the second duration is a duration configured by a network device, and the third duration is configured by the network device or determined based on the first predefined rule.
4. The method according to claim 3, wherein the first duration is determined based on the second duration and the third duration, and the second information comprises information for indicating a system frame number.
5. The method according to any one of claims 2-4, wherein the first time domain position is determined by at least one of the following manners: the first time domain position is determined based on a second predefined rule, wherein the first time domain position is predefined by the second predefined rule; the first time domain position is determined based on a network device configuration; or the first time domain position is determined based on a second time domain position and a fourth duration, wherein the second time domain position is an end position of a random access channel occasion (RO) for sending the first information, and the fourth duration is configured to indicate a time domain offset between the first time domain position and the second time domain position.
6. The method according to claim 5, wherein the first time domain position is determined based on the second time domain position and the fourth duration, and the first time domain position is a first Orthogonal Frequency Division Multiplexing (OFDM) symbol that is offset by the fourth duration from the second time domain position.
7. The method according to claim 5, wherein the first time domain position is determined based on the second time domain position and the fourth duration, and the first time domain position is a first OFDM symbol of a Control Resource Set (CORESET) corresponding to a type 1 common search space set for the terminal to receive a physical downlink control channel of the first network device or the second network device after a position that is offset by the fourth duration from the second time domain position.
8. The method according to any one of claims 1-7, wherein the method further comprises: receiving third information sent by the second network device, wherein the third information is configured to indicate to send the first information to the first network device.
9. The method according to claim 8, wherein sending the first information to the first network device comprises: sending the first information to the first network device based on a target RO; wherein the target RO is determined by at least one of the following manners: the target RO is determined based on fourth information, wherein the third information comprises the fourth information, and the fourth information is configured to indicate the target RO; the target RO is determined based on the fourth information and fifth information, wherein the third information comprises the fourth information and the fifth information, wherein the fourth information is configured to indicate a plurality of ROs, and the fifth information is configured to indicate one of the plurality of ROs as the target RO; or the target RO is determined based on the fourth information and a third predefined rule, wherein the third information comprises the fourth information, the fourth information is configured to indicate the plurality of ROs, and the third predefined rule predefines selection of one of the plurality of ROs as the target RO.
10. The method according to claim 9, wherein the target RO is determined based on fourth information and the third predefined rule, and the method further comprises: sending sixth information, wherein the sixth information is configured to indicate the selected RO to the second network device.
11. The method according to any one of claims 1-10, wherein the method further comprises: sending seventh information, wherein the seventh information is configured to indicate a downlink time difference between the first network device and the second network device.
12. The method according to any one of claims 1-11, wherein the second information is carried in at least one of the following manners: a defined Medium Access Control Protocol Data Unit (MAC PDU) command; or a newly added Medium Access Control Control Element (MAC CE) for carrying the second information.
13. The method according to any one of claims 1-12, wherein the second information comprises at least one of the following parameters: a TA of the candidate cell; a cell identity of the candidate cell; a logical identity of the candidate cell; or a Timing Advance Group (TAG) identity of the candidate cell.
14. The method according to claim 7, wherein the type 1 common search space set of the physical downlink control channel and its associated CORESET are resources of the first network device or the second network device.
15. The method according to claim 7 or 14, wherein receiving, within the first time window, the second information sent by the second network device comprises: receiving, within the first time window, a Physical Downlink Control Channel (PDCCH) for scheduling a Physical Downlink Shared Channel (PDSCH) resource, wherein the PDSCH resource is configured to send the second information.
16. A random access method, performed by a second network device, comprising: sending second information, wherein the second information is configured to indicate a Timing Advance (TA), the TA is determined by a first network device based on first information, the TA is a TA corresponding to the first network device, the second network device is a network device of a serving cell, and the first network device is a network device of a candidate cell.
17. The method according to claim 16, wherein sending the second information comprises: sending the second information within a first time window, wherein the first time window is determined based on a first time domain position and a first duration.
18. The method according to claim 17, wherein the first duration is determined by at least one of the following manners: the first duration is determined based on a first predefined rule, wherein the first duration is predefined by the first predefined rule; the first duration is determined based on a network device configuration; or the first duration is determined based on a second duration and a third duration, wherein the second duration is a duration configured by a network device, and the third duration is configured by the network device or determined based on the first predefined rule.
19. The method according to claim 18, wherein the second information comprises information for indicating a system frame number.
20. The method according to any one of claims 17-19, wherein the first time domain position is determined by at least one of the following manners: the first time domain position is determined based on a second predefined rule, wherein the first time domain position is predefined by the second predefined rule; the first time domain position is determined based on a network device configuration; or the first time domain position is determined based on a second time domain position and a fourth duration, wherein the second time domain position is an end position of a random access channel occasion (RO) for sending the first information, and the fourth duration is configured to indicate a time domain offset between the first time domain position and the second time domain position.

Description

TECHNICAL FIELD The present disclosure relates to the field of communication technologies, and in particular to a random access method and apparatus, a device and a storage medium. BACKGROUND In the related arts, in order to reduce the delay of traditional handover, multiple candidate cells are pre-configured for a terminal. As the terminal moves, a network device determines whether the handover is needed based on beam measurement results of a serving cell and the candidate cells reported by the terminal. When the cell handover is required, the serving cell triggers, through cell handover signaling, the terminal to hand over to a target cell. The target cell is selected from the multiple candidate cells. SUMMARY When a terminal performs the cell handover, it often needs to obtain the Timing Advances (TAs) corresponding to different cells in advance. However, if a cell for which the TA is measured is not a serving cell connected to the terminal, it is impossible for the terminal to receive the TA, resulting in problems such as excessive cell handover delay or interruption. Embodiments of the present disclosure provide a random access method and apparatus, a device and a storage medium. According to a first aspect of embodiments of the present disclosure, there is provided a random access method, which is performed by a terminal and includes: sending first information to a first network device, wherein the first information is configured to determine a Timing Advance (TA), the TA is a TA corresponding to the first network device, and the first network device is a network device of a candidate cell; and receiving second information sent by a second network device, wherein the second information is configured to indicate the TA, and the second network device is a network device of a serving cell. According to a second aspect of embodiments of the present disclosure, there is provided a random access method, which is performed by a second network device and includes: sending second information, wherein the second information is configured to indicate a Timing Advance (TA), the TA is determined by a first network device based on first information, the TA is a TA corresponding to the first network device, the second network device is a network device of a serving cell, and the first network device is a network device of a candidate cell. According to a third aspect of embodiments of the present disclosure, there is provided a random access method, which includes: sending, by a terminal, first information to a first network device, wherein the first information is configured to determine a Timing Advance (TA), the TA is a TA corresponding to the first network device, and the first network device is a network device of a candidate cell; sending, by a second network device, second information to the terminal, wherein the second information is configured to indicate the TA, and the second network device is a network device of a serving cell; and receiving, by the terminal, the second information sent by the second network device. According to a fourth aspect of embodiments of the present disclosure, there is provided a terminal, including: a transceiving module; the transceiving module is configured to send first information to a first network device, wherein the first information is configured to determine a Timing Advance (TA), the TA is a TA corresponding to the first network device, and the first network device is a network device of a candidate cell; and the transceiving module is further configured to receive second information sent by a second network device, wherein the second information is configured to indicate the TA, and the second network device is a network device of a serving cell. According to a fifth aspect of embodiments of the present disclosure, there is provided a network device, including: a transceiving module; the transceiving module is configured to send second information, wherein the second information is configured to indicate a Timing Advance (TA), the TA is determined by a first network device based on first information, the TA is a TA corresponding to the first network device, the second network device is a network device of a serving cell, and the first network device is a network device of a candidate cell. According to a sixth aspect of embodiments of the present disclosure, there is provided a terminal, including: one or more processors; wherein the terminal is configured to perform the first aspect and any one of the random access methods in the first aspect. According to a seventh aspect of embodiments of the present disclosure, there is provided a network device, including: one or more processors; wherein the network device is configured to perform the second aspect and any one of the random access methods in the second aspect. According to an eighth aspect of embodiments of the present disclosure, there is provided a communication system, including a terminal and a network devic