US-12621895-B2 - Communications method and apparatus

US12621895B2US 12621895 B2US12621895 B2US 12621895B2US-12621895-B2

Abstract

The disclosure provides communication methods and apparatuses. One example method includes that after receiving a cell handover command, a terminal device determines discontinuous reception (DRX) configuration information of a target cell. The DRX configuration information of the target cell is consistent with DRX configuration information of a source cell. The terminal device exchanges data at least with the source cell based on the DRX configuration information of the source cell, or with the target cell based on the DRX configuration information of the target cell.

Inventors

Yan Chen
Le Jin
Bingguang Peng
Xi Zhang

Assignees

HUAWEI TECHNOLOGIES CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20220329

Claims (12)

1 . A communications method, wherein the method comprises: prior to initiating handover, determining that a short discontinuous reception (DRX) cycle parameter is absent from DRX configuration information of a source cell or receiving, from the source cell, a reconfiguration message indicating to delete the short DRX cycle parameter in the DRX configuration information of the source cell, wherein the determining or receiving is performed to adapt DRX configuration for dual active protocol stack (DAPS)-based handover; determining DRX configuration information of a target cell in response to receiving a cell handover command, wherein the DRX configuration information of the target cell is consistent with DRX configuration information of a source cell to enable synchronized sleep intervals between the source cell and the target cell during dual connectivity; exchanging data with at least one of the source cell based on the DRX configuration information of the source cell or the target cell based on the DRX configuration information of the target cell while maintaining connections to both the source cell and the target cell; determining that the DRX configuration information of the target cell is invalid when a radio link failure occurs in the target cell; and deleting the DRX configuration information of the target cell.
2 . The method according to claim 1 , wherein the method further comprises: determining that the DRX configuration information of the source cell is invalid when a radio link failure occurs in the source cell; and in response to determining that the DRX configuration information of the source cell is invalid: initiating access to the target cell; or maintaining a connection to the target cell.
3 . The method according to claim 1 , wherein the reconfiguration message further indicates to modify a long DRX cycle parameter in the DRX configuration information of the source cell.
4 . The method according to claim 1 , wherein the DRX configuration information of the target cell is consistent with the DRX configuration information of the source cell under at least one of the following conditions: when the DRX configuration information of the source cell comprises a long cycle parameter and a short cycle parameter, a long cycle parameter of the target cell is the same as a long cycle parameter of the source cell, and a short cycle parameter of the target cell is the same as a short cycle parameter of the source cell; when the DRX configuration information of the source cell comprises the short cycle parameter and the DRX configuration information of the target cell does not comprise the short cycle parameter, the long cycle parameter of the target cell is the same as the short cycle parameter of the source cell, or the long cycle parameter of the target cell is an integer multiple of the short cycle parameter of the source cell, or the short cycle parameter of the source cell is an integer multiple of the long cycle parameter of the target cell; when the DRX configuration information of the source cell comprises the short cycle parameter and the DRX configuration information of the target cell comprises the short cycle parameter, the short cycle parameter of the target cell is the same as the short cycle parameter of the source cell, or the short cycle parameter of the target cell is an integer multiple of the short cycle parameter of the source cell, or the short cycle parameter of the source cell is an integer multiple of the short cycle parameter of the target cell; when the DRX configuration information of the source cell comprises the long cycle parameter and the DRX configuration information of the target cell does not comprise the short cycle parameter, the long cycle parameter of the target cell is the same as the long cycle parameter of the source cell, or the long cycle parameter of the target cell is an integer multiple of the long cycle parameter of the source cell, or the long cycle parameter of the source cell is an integer multiple of the long cycle parameter of the target cell; or when the DRX configuration information of the source cell comprises the long cycle parameter and the DRX configuration information of the target cell comprises the short cycle parameter, the short cycle parameter of the target cell is the same as the long cycle parameter of the source cell, or the short cycle parameter of the target cell is an integer multiple of the long cycle parameter of the source cell, or the long cycle parameter of the source cell is an integer multiple of the short cycle parameter of the target cell.
5 . A communications apparatus, wherein the apparatus comprises: at least one processor; a memory storing programming instructions for execution by the at least one processor and cause the at least one processor to: prior to initiating handover, determine that a short discontinuous reception (DRX) cycle parameter is absent from DRX configuration information of a source cell or receiving, from the source cell, a reconfiguration message indicating to delete the short DRX cycle parameter in the DRX configuration information of the source cell, wherein the determining or receiving is performed to adapt DRX configuration for dual active protocol stack (DAPS)-based handover; determine DRX configuration information of a target cell in response to receiving a cell handover command, wherein the DRX configuration information of the target cell is consistent with DRX configuration information of a source cell to enable synchronized sleep intervals between the source cell and the target cell during dual connectivity; exchange data with at least one of the source cell based on the DRX configuration information of the source cell or the target cell based on the DRX configuration information of the target cell while maintaining connections to both the source cell and the target cell; determine that the DRX configuration information of the target cell is invalid when a radio link failure occurs in the target cell; and delete the DRX configuration information of the target cell.
6 . The apparatus according to claim 5 , wherein the programming instructions further causes the at least one processor to determine that the DRX configuration information of the source cell is invalid when a radio link failure occurs in the source cell; and in response to determining that the DRX configuration information of the source is invalid, the programming instructions cause the at least on processor to: initiate access to the target cell; or maintain a connection to the target cell.
7 . The apparatus according to claim 5 , wherein the programming instructions further cause the at least one processor to: wherein the reconfiguration message further indicates to modify a long DRX cycle parameter in the DRX configuration information of the source cell.
8 . The apparatus according to claim 5 , wherein the DRX configuration information of the target cell is consistent with the DRX configuration information of the source cell under at least one of the following conditions: when the DRX configuration information of the source cell comprises a long cycle parameter and a short cycle parameter, a long cycle parameter of the target cell is the same as a long cycle parameter of the source cell, and a short cycle parameter of the target cell is the same as a short cycle parameter of the source cell; when the DRX configuration information of the source cell comprises the short cycle parameter and the DRX configuration information of the target cell does not comprise the short cycle parameter, the long cycle parameter of the target cell is the same as the short cycle parameter of the source cell, or the long cycle parameter of the target cell is an integer multiple of the short cycle parameter of the source cell, or the short cycle parameter of the source cell is an integer multiple of the long cycle parameter of the target cell; when the DRX configuration information of the source cell comprises the short cycle parameter and the DRX configuration information of the target cell comprises the short cycle parameter, the short cycle parameter of the target cell is the same as the short cycle parameter of the source cell, or the short cycle parameter of the target cell is an integer multiple of the short cycle parameter of the source cell, or the short cycle parameter of the source cell is an integer multiple of the short cycle parameter of the target cell; when the DRX configuration information of the source cell comprises the long cycle parameter and the DRX configuration information of the target cell does not comprise the short cycle parameter, the long cycle parameter of the target cell is the same as the long cycle parameter of the source cell, or the long cycle parameter of the target cell is an integer multiple of the long cycle parameter of the source cell, or the long cycle parameter of the source cell is an integer multiple of the long cycle parameter of the target cell; or when the DRX configuration information of the source cell comprises the short cycle parameter and the DRX configuration information of the target cell comprises the short cycle parameter, the short cycle parameter of the target cell is the same as the long cycle parameter of the source cell, or the short cycle parameter of the target cell is an integer multiple of the long cycle parameter of the source cell, or the long cycle parameter of the source cell is an integer multiple of the short cycle parameter of the target cell.
9 . A non-transitory computer readable medium storing one or more programming instructions executable by at least one processor to cause to cause the at least one processor to: prior to initiating handover, determine that a short discontinuous reception (DRX) cycle parameter is absent from DRX configuration information of a source cell or receive, from the source cell, a reconfiguration message indicating to delete the short DRX cycle parameter in the DRX configuration information of the source cell, wherein the determining or receiving is performed to adapt DRX configuration for dual active protocol stack (DAPS)-based handover; determine DRX configuration information of a target cell in response to receiving a cell handover command, wherein the DRX configuration information of the target cell is consistent with DRX configuration information of a source cell to enable synchronized sleep intervals between the source cell and the target cell during dual connectivity; exchange data with at least one of the source cell based on the DRX configuration information of the source cell or the target cell based on the DRX configuration information of the target cell while maintaining connections to both the source cell and the target cell; determine that the DRX configuration information of the target cell is invalid when a radio link failure occurs in the target cell; and delete the DRX configuration information of the target cell.
10 . The non-transitory computer readable medium according to claim 9 , wherein the programming instructions further causes the at least one processor to determine that the DRX configuration information of the source cell is invalid when a radio link failure occurs in the source cell; and in response to determining that the DRX configuration information of the source is invalid, the programming instructions cause the at least on processor to: initiate access to the target cell; or maintain a connection to the target cell.
11 . The non-transitory computer readable medium according to claim 9 , wherein the programming instructions further cause the at least one processor to: wherein the reconfiguration message further indicates to modify a long DRX cycle parameter in the DRX configuration information of the source cell.
12 . The non-transitory computer readable medium according to claim 9 , wherein the DRX configuration information of the target cell is consistent with the DRX configuration information of the source cell under at least one of the following conditions: when the DRX configuration information of the source cell comprises a long cycle parameter and a short cycle parameter, a long cycle parameter of the target cell is the same as a long cycle parameter of the source cell, and a short cycle parameter of the target cell is the same as a short cycle parameter of the source cell; when the DRX configuration information of the source cell comprises the short cycle parameter and the DRX configuration information of the target cell does not comprise the short cycle parameter, the long cycle parameter of the target cell is the same as the short cycle parameter of the source cell, or the long cycle parameter of the target cell is an integer multiple of the short cycle parameter of the source cell, or the short cycle parameter of the source cell is an integer multiple of the long cycle parameter of the target cell; when the DRX configuration information of the source cell comprises the short cycle parameter and the DRX configuration information of the target cell comprises the short cycle parameter, the short cycle parameter of the target cell is the same as the short cycle parameter of the source cell, or the short cycle parameter of the target cell is an integer multiple of the short cycle parameter of the source cell, or the short cycle parameter of the source cell is an integer multiple of the short cycle parameter of the target cell; when the DRX configuration information of the source cell comprises the long cycle parameter and the DRX configuration information of the target cell does not comprise the short cycle parameter, the long cycle parameter of the target cell is the same as the long cycle parameter of the source cell, or the long cycle parameter of the target cell is an integer multiple of the long cycle parameter of the source cell, or the long cycle parameter of the source cell is an integer multiple of the long cycle parameter of the target cell; or when the DRX configuration information of the source cell comprises the short cycle parameter and the DRX configuration information of the target cell comprises the short cycle parameter, the short cycle parameter of the target cell is the same as the long cycle parameter of the source cell, or the short cycle parameter of the target cell is an integer multiple of the long cycle parameter of the source cell, or the long cycle parameter of the source cell is an integer multiple of the short cycle parameter of the target cell.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/CN2019/109734, filed on Sep. 30, 2019, the disclosure of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD This application relates to the field of communications technologies, and in particular, to a communications method and apparatus. BACKGROUND Because a concept of a beam is introduced into new radio (NR), a beam scanning delay introduced by a high frequency beamforming technology increases a handover interruption time. In addition, a beamforming feature causes relatively small coverage. Consequently, handover reliability is reduced. When a terminal device moves or rotates, the terminal device may experience extremely fast signal degradation. In addition, a channel condition difference between a line of sight (LoS) and a non-line of sight (NLoS) in the NR is relatively large, and a signal strength difference between the LOS and the NLOS reaches tens of dB. Consequently, more handover failures and a higher ping-pong handover probability may be caused. Therefore, handover in the NR is more challenging than that in a long term evolution (LTE) communications system. In addition, ultra-reliable low-latency communication (URLLC) services of the NR require an end-to-end latency of 1 ms in some cases. A handover interruption of 0 ms is very important to provide seamless service experience. A dual-access protocol stack (DAPS) handover solution may implement the handover interruption of 0 ms. FIG. 1 is a schematic diagram of a DAPS handover procedure. A source cell sends a handover command (HO cmd) to a terminal device, the terminal device initiates access to a target cell, and then the terminal device completes the access to the target cell. In this solution, after the terminal device initiates access, the terminal device continues to communicate with the source cell; and after the terminal device completes the access, the terminal device establishes a connection to the target cell. A scenario in which a terminal device simultaneously communicates with two cells is a dual-cell connection (“dual connection” for short) interval shown in FIG. 1. Finally, after the target cell initiates signaling for deleting the source cell, the terminal device communicates with only the target cell to complete handover. In the handover process, the terminal device simultaneously communicates with the source cell and the target cell, to implement a handover interruption of 0 ms. In an intra-frequency (intra-freq) synchronous/asynchronous scenario and an intra-band continuous synchronous/asynchronous scenario, FIG. 2 shows a structure of radio frequency transceiving and processing of a terminal device. A baseband processing (BBP) module of a source cell and a BBP module of a target cell of the terminal device are connected to a same radio frequency (RF) module, in other words, a BBP channel of the source cell and a BBP channel of the target cell are connected to a same RF channel. This can reduce power consumption of the terminal device. To further reduce the power consumption of the terminal device, a discontinuous reception (DRX) technology is introduced. In a web browsing scenario, a voice over long term evolution (VOLTE) call scenario, or the like, a modem of the terminal device is in a burst working state, and a proportion of a working time to a total time is relatively small, so that working and power saving can be implemented by using a burst transceiving mechanism. To reduce the power consumption of the terminal device, a network device sends a DRX configuration parameter to the terminal device. In the DAPS handover solution, especially in the foregoing intra-freq and intra-band continuous scenarios, how the source cell and the target cell configure DRX for the terminal device to reduce the power consumption of the terminal device is a problem that needs to be resolved in this application. SUMMARY Embodiments of this application provide a communications method and apparatus, to reduce power consumption of a terminal device. According to a first aspect, a communications method is provided. The method includes: After a terminal device receives a cell handover command, when the terminal device is connected to both a source cell and a target cell, the terminal device determines a discontinuous reception DRX configuration information for the source cell and the target cell. The DRX configuration solution includes any one of the following: DRX configuration information of the source cell and DRX configuration information of the target cell are independently configured; the DRX configuration information of the source cell is consistent with the DRX configuration information of the target cell; neither the DRX configuration information of the source cell nor the DRX configuration information of the target cell is configured or is valid; or the DRX configuration information of the source cell remain