US-12621837-B2 - Method for releasing uplink resource, terminal device, and network device

US12621837B2US 12621837 B2US12621837 B2US 12621837B2US-12621837-B2

Abstract

A method for releasing an uplink resource, a terminal device and a network device are provided. The method includes that: a terminal device transmits a handover complete message through an uplink grant resource in a first type of handover; and the terminal device releases the uplink grant resource in case that a preset condition is met. The uplink grant resource is an uplink resource, configured in a handover command, for accessing a target network device. The preset condition includes at least one of: an uplink timer expires, a first downlink channel for scheduling an uplink transmission resource for new transmission is monitored, or indication information for instructing to release the uplink grant resource is received.

Inventors

Haitao Li

Assignees

GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD.

Dates

Publication Date: 20260505
Application Date: 20220909

Claims (15)

1 . A method for releasing an uplink resource, comprising: transmitting, by a terminal device, a handover complete message through an uplink grant resource in a first type of handover; and releasing, by the terminal device, the uplink grant resource in case that a preset condition is met, wherein the uplink grant resource is an uplink resource, configured in a handover command, for accessing a target network device, and wherein the preset condition comprises at least one of: an uplink timer expires, a first downlink channel for scheduling an uplink transmission resource for new transmission is monitored, or indication information for instructing to release the uplink grant resource is received, the method further comprising: starting, by the terminal device, when transmitting the handover complete message, the uplink timer, and performing monitoring of the first downlink channel and a second downlink channel for scheduling an uplink transmission resource for retransmission, wherein the first downlink channel is a Physical Downlink Control Channel (PDCCH) scrambled with a Cell-Radio Network Temporary Identifier (C-RNTI), and the second downlink channel is a PDCCH scrambled with a Configured Scheduling-Radio Network Temporary Identifier (CS-RNTI); in case that the second downlink channel for scheduling the uplink transmission resource for retransmission is monitored, performing, by the terminal device, retransmission based on the uplink transmission resource scheduled by the second downlink channel, and restarting the uplink timer; and in case that the uplink timer expires, determining, by the terminal device, that the handover complete message is correctly received by a network device, and releasing the uplink grant resource.
2 . The method of claim 1 , wherein the first type of handover is Random Access Channel-less (RACH-less) handover.
3 . The method of claim 1 , further comprising: in case that the first downlink channel for scheduling the uplink transmission resource for new transmission is monitored, determining, by the terminal device, that the handover complete message is correctly received by a network device, and releasing the uplink grant resource.
4 . The method of claim 1 , further comprising: in case that the first downlink channel for scheduling the uplink transmission resource for new transmission is monitored, transmitting, by the terminal device, new data based on the uplink transmission resource scheduled by the first downlink channel, and restarting the uplink timer; wherein releasing, by the terminal device, the uplink grant resource in case that the preset condition is met comprises: in case that the terminal device receives the indication information for instructing to release the uplink grant resource, releasing the uplink grant resource, wherein the indication information is carried in at least one of: a Media Access Control (MAC) Control Element (CE), Radio Resource Control (RRC) signaling, or a Physical Downlink Control Channel (PDCCH).
5 . The method of claim 4 , further comprising: in case that the uplink timer is running when the UL grant resource is released, stopping, by the terminal device, the uplink timer.
6 . The method of claim 1 , further comprising: receiving, by the terminal device, the handover command, wherein the handover command comprises Random Access Channel (RACH) skip information for indicating the uplink grant resource, wherein the RACH skip information comprises at least one of: a first parameter representing a start radio frame of the uplink grant resource; a second parameter representing a start sub-frame of the uplink grant resource; a duration parameter of the uplink timer; CS-RNTI information; a third parameter representing a number of Hybrid Automatic Repeat reQuest (HARQ) processes available for the uplink grant resource; a time interval between adjacent uplink grant resources; or a time-frequency resource position of the uplink grant resource, wherein the method further comprises: performing, by the terminal device, downlink synchronization with the target network device, and determining start time of the uplink grant resource based on the first parameter and the second parameter; in case that time of completion of the downlink synchronization is not later than the start time of the uplink grant resource, transmitting the handover complete message on a first available uplink grant resource; and in case that the time of completion of the downlink synchronization is later than the start time of the uplink grant resource, transmitting the handover complete message on a first available uplink grant resource after the time of completion of the downlink synchronization.
7 . A terminal device, comprising: a processor; a transceiver; and a memory is coupled with the transceiver and the processor, and is configured to store computer programs that, when executed by the processor, cause the processor to: control the transceiver to transmit a handover complete message through an uplink grant resource in a first type of handover; and release the uplink grant resource in case that a preset condition is met, wherein the uplink grant resource is an uplink resource, configured in a handover command, for accessing a target network device, and wherein the preset condition comprises at least one of: an uplink timer expires, a first downlink channel for scheduling an uplink transmission resource for new transmission is monitored, or indication information for instructing to release the uplink grant resource is received, wherein the processor is configured to, when transmitting the handover complete message via the transceiver, start the uplink timer, and perform monitoring of the first downlink channel and a second downlink channel for scheduling an uplink transmission resource for retransmission, wherein the first downlink channel is a Physical Downlink Control Channel (PDCCH) scrambled with a Cell-Radio Network Temporary Identifier (C-RNTI), and the second downlink channel is a PDCCH scrambled with a Configured Scheduling-Radio Network Temporary Identifier (CS-RNTI); in case that the second downlink channel for scheduling the uplink transmission resource for retransmission is monitored, control the transceiver to perform retransmission based on the uplink transmission resource scheduled by the second downlink channel, and restart the uplink timer; and in case that the uplink timer expires, determine that the handover complete message is correctly received by a network device and release the uplink grant resource.
8 . The terminal device of claim 7 , wherein the first type of handover is Random Access Channel-less (RACH-less) handover.
9 . The terminal device of claim 7 , wherein the processor is configured to, in case that the first downlink channel for scheduling the uplink transmission resource for new transmission is monitored, determine that the handover complete message is correctly received by a network device, and release the uplink grant resource.
10 . The terminal device of claim 7 , wherein the processor is configured to: in case that the first downlink channel for scheduling the uplink transmission resource for new transmission is monitored, control the transceiver to transmit new data based on the uplink transmission resource scheduled by the first downlink channel, and restart the uplink timer; and in case that the indication information for instructing to release the uplink grant resource is received, release the uplink grant resource, wherein the indication information is carried in at least one of: a Media Access Control (MAC) Control Element (CE), Radio Resource Control (RRC) signaling, or a Physical Downlink Control Channel (PDCCH).
11 . The terminal device of claim 10 , wherein the processor is configured to stop the uplink timer in case that the uplink timer is running when the uplink grant resource is released.
12 . The terminal device of claim 7 , wherein the processor is configured to control the transceiver to receive the handover command, wherein the handover command comprises Random Access Channel (RACH) skip information for indicating the uplink grant resource, wherein the RACH skip information comprises at least one of: a first parameter representing a start radio frame of the uplink grant resource; a second parameter representing a start sub-frame of the uplink grant resource; a duration parameter of the uplink timer; CS-RNTI information; a third parameter representing a number of Hybrid Automatic Repeat reQuest (HARQ) processes available for the uplink grant resource; a time interval between adjacent uplink grant resources; or a time-frequency resource position of the uplink grant resource, wherein the processor is configured to perform downlink synchronization with the target network device, and determine start time of the uplink grant resource based on the first parameter and the second parameter; control, in case that time of completion of the downlink synchronization is not later than the start time of the uplink grant resource, the transceiver to transmit the handover complete message on a first available uplink grant resource, and control, in case that the time of completion of the downlink synchronization is later than the start time of the uplink grant resource, the transceiver to transmit the handover complete message on a first available uplink grant resource after the time of completion of the downlink synchronization.
13 . A network device, comprising: a processor; a transceiver; and a memory is coupled with the transceiver and the processor, and is configured to store computer programs that, when executed by the processor, cause the processor to: control the transceiver to receive a handover complete message transmitted by a terminal device through an uplink grant resource in a first type of handover; and reclaim the uplink grant resource released by the terminal device, wherein the uplink grant resource is an uplink resource, configured for the terminal device in a handover command, for accessing a target network device, wherein the processor is configured to control the transceiver to transmit at least one of a first downlink channel for scheduling an uplink transmission resource for new transmission or a second downlink channel for scheduling an uplink transmission resource for retransmission to the terminal device for monitoring during an operation of an uplink timer, the uplink timer being started when the handover complete message is transmitted, wherein the first downlink channel is a Physical Downlink Control Channel (PDCCH) scrambled with a Cell-Radio Network Temporary Identifier (C-RNTI), and the second downlink channel is a PDCCH scrambled with a Configured Scheduling-Radio Network Temporary Identifier (CS-RNTI); wherein the monitoring of the second downlink channel for scheduling the uplink transmission resource for retransmission triggers retransmission of the terminal device based on the uplink transmission resource scheduled by the second downlink channel, and restarting of the uplink timer; and expiration of the restarted uplink timer is considered as an indication that the handover complete message is correctly received by the network device, and an indication that the uplink grant resource is released by the terminal device.
14 . The network device of claim 13 , wherein the first type of handover is Random Access Channel-less (RACH-less) handover.
15 . The network device of claim 13 , wherein the processor is configured to control the transceiver to transmit the handover command to the terminal device, wherein the handover command comprises Random Access Channel (RACH) skip information for indicating the uplink grant resource, wherein the RACH skip information comprises at least one of: a first parameter representing a start radio frame of the uplink grant resource; a second parameter representing a start sub-frame of the uplink grant resource; a duration parameter of the uplink timer; CS-RNTI information; a third parameter representing a number of Hybrid Automatic Repeat reQuest (HARQ) processes available for the uplink grant resource; a time interval between adjacent uplink grant resources; or a position of the uplink grant resource.

Description

This application is a continuation of PCT international Application No. PCT/CN2020/078472 filed on Mar. 9, 2020, the contents of which are incorporated herein by reference in its entirety. TECHNICAL FIELD Background At present, a target cell may reasonably configure a time-domain position of an uplink resource in a handover command during a handover process, such that a terminal device transmits a handover complete message when accessing the target cell. The uplink resource in the handover command is relatively small, and is mainly used for the terminal device to report the handover complete message but not suitable for uplink transmission of ordinary data. Therefore, how to avoid the waste of uplink transmission resources becomes a problem that needs to be solved. SUMMARY The disclosure relates to the field of communication technologies, and provides a method for releasing an uplink resource, a terminal device, and a network device. In a first aspect, there is provided a method for releasing an uplink resource, which includes the following operations. A terminal device transmits a handover complete message through an uplink grant resource in a first type of handover, and the terminal device releases the uplink grant resource in case that a preset condition is met. The UL grant resource is an uplink resource, configured in a handover command, for accessing a target network device. The preset condition includes at least one of: an uplink timer expires, a first downlink channel for scheduling an uplink transmission resource for new transmission is monitored, or indication information for instructing to release the uplink grant resource is received. In a second aspect, there is provided a method for releasing an uplink resource, which includes the following operations. A network device receives a handover complete message transmitted by a terminal device through an uplink grant resource in a first type of handover, and the network device reclaims the uplink grant resource released by the terminal device. The UL grant resource is an uplink resource, configured for the terminal device in a handover command, for accessing a target network device. In a third aspect, there is provided a terminal device, which includes a processor, a transceiver, and a memory coupled with the processor and the transceiver. The memory is configured to store computer programs that, when executed by the processor, cause the processor to: control the transceiver to transmit a handover complete message through an uplink grant resource in a first type of handover; and release the uplink grant resource in case that a preset condition is met. The UL grant resource is an uplink resource, configured in a handover command, for accessing a target network device. The preset condition includes at least one of: an uplink timer expires, a first downlink channel for scheduling an uplink transmission resource for new transmission is monitored, or indication information for instructing to release the uplink grant resource is received. In a fourth aspect, there is provided a network device, which includes a processor, a transceiver, and a memory coupled with the processor and the transceiver. The memory is configured to store computer programs that, when executed by the processor, cause the processor to: control the transceiver to receive a handover complete message transmitted by a terminal device through an uplink grant resource in a first type of handover; and reclaim the uplink grant resource released by the terminal device. The UL grant resource is an uplink resource, configured for the terminal device in a handover command, for accessing a target network device. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a first diagram of architecture of a communication system according to an embodiment of the disclosure. FIG. 2 is a first flowchart of a method for releasing an uplink resource according to an embodiment of the disclosure. FIG. 3 is a second flowchart of a method for releasing an uplink resource according to an embodiment of the disclosure. FIG. 4 is a diagram of a handover process. FIG. 5 is a third flowchart of a method for releasing an uplink resource according to an embodiment of the disclosure. FIG. 6 is a first diagram of a scenario in which an uplink resource is released according to an embodiment of the disclosure. FIG. 7 is a fourth flowchart of a method for releasing an uplink resource according to an embodiment of the disclosure. FIG. 8 is a second diagram of a scenario in which an uplink resource is released according to an embodiment of the disclosure. FIG. 9 is a flowchart of a process for determining start time of an uplink grant resource according to an embodiment of the disclosure. FIG. 10 is a diagram of a scenario involving a process for determining start time of an uplink grant resource according to an embodiment of the disclosure. FIG. 11 is a structure diagram of composition of a terminal device according to an embodiment o