CN-121986532-A - Terminal, wireless communication method and base station

CN121986532ACN 121986532 ACN121986532 ACN 121986532ACN-121986532-A

Abstract

The terminal according to one aspect of the present disclosure includes a receiving unit that receives setting information and a cell handover command related to at least one of a setting of a random access procedure for a candidate cell and a setting based on a timing advance measurement of the terminal, and a control unit that determines at least one of an application of the random access procedure after receiving the cell handover command and a type of the applied random access procedure based on at least one of the setting information related to the candidate cell indicated by the cell handover command, a timing advance field included in the cell handover command, and a specific field included in the cell handover command.

Inventors

OKUMURA MAMORU
MATSUMURA YUSUKE
HARADA HIROYASU
WANG JING

Assignees

株式会社NTT都科摩

Dates

Publication Date: 20260505
Application Date: 20241003
Priority Date: 20231010

Claims (6)

1. A terminal, comprising: a receiving unit for receiving setting information and a cell switching command related to at least one of a setting of a random access procedure for a candidate cell and a setting based on a timing advance measurement of a terminal, and And a control unit configured to determine at least one of the presence or absence of application of a random access procedure after receiving the cell handover command and the type of the applied random access procedure, based on at least one of the setting information on the candidate cell indicated by the cell handover command, a timing advance field included in the cell handover command, and a specific field included in the cell handover command.
2. The terminal of claim 1, wherein, In the case where the random access procedure is performed after the reception of the cell handover command, the control unit controls the random access procedure based on a downlink control channel transmitted in a candidate cell indicated by the cell handover command or the cell handover command.
3. The terminal of claim 1, wherein, And under the condition that the non-contention type random access process is carried out after the cell switching command is received, the control unit controls the sending of the non-contention type random access preamble based on the random access related information contained in the cell switching command.
4. The terminal of claim 1, wherein, When the non-contention random access procedure is performed after the cell handover command is received, the control unit controls transmission of the non-contention random access preamble based on the value of the timing advance field when a specific field of the cell handover command is a specific value.
5. A wireless communication method for a terminal includes: A step of receiving setting information and a cell switching command related to at least one of a setting of a random access procedure for a candidate cell and a setting based on a timing advance measurement of a terminal, and And determining whether or not to apply a random access procedure after receiving the cell handover command and at least one of a type of the applied random access procedure based on at least one of the setting information on the candidate cell indicated by the cell handover command, a timing advance field included in the cell handover command, and a specific field included in the cell handover command.
6. A base station, comprising: a transmitting unit for transmitting setting information and a cell switching command related to at least one of a setting of a random access procedure for a candidate cell and a setting based on a timing advance measurement of a terminal, and And a control unit configured to instruct at least one of the presence or absence of application of a random access procedure after receiving the cell handover command and the type of the applied random access procedure, based on at least one of the setting information on the candidate cell indicated by the cell handover command, a timing advance field included in the cell handover command, and a specific field included in the cell handover command.

Description

Terminal, wireless communication method and base station Technical Field The present disclosure relates to a terminal, a wireless communication method, and a base station in a next generation mobile communication system. Background In a universal mobile telecommunications system (Universal Mobile Telecommunication System (UMTS)) network, long term evolution (Long Term Evolution (LTE)) has been standardized for the purpose of further high-speed data rates, low latency, and the like (non-patent document 1). Further, for the purpose of further increasing capacity, height, and the like of LTE (third generation partnership project (3 rd Generation Partnership Project (3 GPP (registered trademark))) versions (Release (rel.)) 8 and 9), LTE-Advanced (3 GPP rel.10-14) has been standardized. Subsequent systems of LTE (e.g., also referred to as fifth generation mobile communication system (5 th generation mobile communication system (5G)), 5g+ (plus), sixth generation mobile communication system (6 th generation mobile communication system (6G)), new Radio (NR)), 3gpp rel.15 later, and the like are also being studied. Prior art literature Non-patent literature Non-patent document 1：3GPP TS 36.300 V8.12.0 "Evolved Universal Terrestrial Radio Access （E-UTRA） and Evolved Universal Terrestrial Radio Access Network （E-UTRAN）; Overall description; Stage 2 （Release 8）",2010, month 4 Disclosure of Invention Problems to be solved by the invention In future wireless communication systems (e.g., NR), it is being studied to use L1L2 trigger mobility (L1L 2-TRIGGERED MOBILITY (LTM)) specified in rel.18 when a terminal (User terminal), user Equipment (UE)) performs inter-cell movement. In the case of applying the LTM of rel.18, the interruption time of the cell handover can be shortened. In the LTM procedure of rel.18, it is assumed that after the UE receives control information indicating a cell handover, RACH-based LTM using a random access procedure and RACH-free LTM not using a random access procedure are supported for a candidate/target cell. In this case, no sufficient study has been made on how to control the LTM procedure (e.g., RACH-based LTM/RACH-free LTM). It is therefore an object of the present disclosure to provide a terminal, a wireless communication method, and a base station capable of appropriately performing cell handover while supporting L1L2 trigger mobility (L1L 2-TRIGGERED MOBILITY (LTM)). Means for solving the problems The terminal according to one aspect of the present disclosure includes a receiving unit that receives setting information and a cell handover command related to at least one of a setting of a random access procedure for a candidate cell and a setting based on a timing advance measurement of the terminal, and a control unit that determines at least one of an application of the random access procedure after receiving the cell handover command and a type of the applied random access procedure based on at least one of the setting information related to the candidate cell indicated by the cell handover command, a timing advance field included in the cell handover command, and a specific field included in the cell handover command. Effects of the invention According to an aspect of the present disclosure, cell handover can be appropriately performed with L1L2 trigger mobility (L1L 2-TRIGGERED MOBILITY (LTM)) supported. Drawings Fig. 1A is a diagram showing an example of mobility of a UE in rel.17. Fig. 1B is a diagram showing an example of mobility of a UE in rel.18. FIG. 2 is a diagram showing an example of LTM studied in Rel.18. Fig. 3 is a diagram showing a process between UE-base stations (gnbs) of the LTM in rel.18. Fig. 4 is a diagram showing a process of early DL synchronization between UE-base stations (gNB) of LTM in rel.18. Fig. 5 is a diagram showing a process of early UL synchronization between UE-base stations (gnbs) of LTM in rel.18. Fig. 6 is a diagram showing an example of a Timing Advance Group (TAG) to which a cell included in a cell group belongs. Fig. 7 is a diagram showing an example of a MAC CE for a timing advance command. Fig. 8 is a diagram showing another example of the MAC CE for the timing advance command. Fig. 9 is a diagram showing an example of TAG setting in the case where association of TAG IDs with candidate cells is supported. Fig. 10 is a diagram showing an example of an LTM procedure using UE-based TA measurement. Fig. 11 is a diagram showing an example of a cell handover command according to the first embodiment. Fig. 12 is a diagram showing an example of a cell handover command according to the second embodiment. Fig. 13 is a diagram showing an example of a schematic configuration of a radio communication system according to an embodiment. Fig. 14 is a diagram showing an example of a configuration of a base station according to an embodiment. Fig. 15 is a diagram showing an example of a configuration of a user terminal according to an embodiment. Fig. 16 is a