CN-114599121-B - Method executed by user equipment and user equipment

Abstract

The invention provides a method executed by user equipment and the user equipment. The method executed by the user equipment is a method of RRC connection reestablishment procedure executed by the user equipment UE, and comprises the steps that the UE triggers or starts the RRC connection reestablishment procedure, in the process of starting the RRC connection reestablishment, the UE starts a timer T311 and executes cell selection or relay selection, and in the condition that the UE selects a proper cell or the UE selects a proper relay, the UE stops T311, wherein the proper cell is the cell with the measured value or the level value meeting the rule of the cell selection, and the proper relay is the relay with the measured value or the level value meeting the rule of the relay selection.

Inventors

• ZHANG CHONGMING
• LIU RENMAO

Assignees

• 夏普株式会社

Dates

Publication Date

20260512

Application Date

20201203

Claims (2)

1. 1. A method performed by a user device, the method comprising: starting a first timer and performing selection when starting a Radio Resource Control (RRC) connection reestablishment procedure; When the selection is performed, the first timer is stopped and a second timer is started, irrespective of whether the selection is a suitable cell selection or a suitable relay selection, wherein, Using a first value to start the second timer, if the appropriate cell selection is performed, and Using a second value to start the second timer if the appropriate relay selection is performed, and And stopping the second timer when the RRC reestablishment message is received.
2. 2. A user equipment, comprising: Processor, and A memory storing instructions that, Wherein the instructions, when executed by the processor, cause the user equipment to: starting a first timer and performing selection when starting a Radio Resource Control (RRC) connection reestablishment procedure; When the selection is performed, the first timer is stopped and a second timer is started, irrespective of whether the selection is a suitable cell selection or a suitable relay selection, wherein, Using a first value to start the second timer, if the appropriate cell selection is performed, and Using a second value to start the second timer if the appropriate relay selection is performed, and And stopping the second timer when the RRC reestablishment message is received.

Description

Method executed by user equipment and user equipment Technical Field The present invention relates to the field of wireless communication technology, and more specifically, to a method performed by a user equipment and a corresponding user equipment. Background In order to provide services, in one scenario, a remote UE (remote UE) may be communicatively connected to a base station via a relay UE (relay UE). After the remote UE establishes an RRC connection with the base station through the relay UE, the remote UE is in an RRC connected state. In the following case, the remote UE may trigger the RRC connection reestablishment procedure. In case 1, the connection between the remote UE and the relay UE fails, for example, the remote UE detects that the HARQ retransmission number exceeds a preset threshold value; Case 2, the remote UE receives a handover command sent by the base station to the remote UE, which may be to handover remot UE from the currently connected relay UE to another relay UE (target relay UE) or to handover to a cell (target cell). The remote UE fails in establishing a connection with the target relay UE or the target cell, resulting in handover failure. In the prior art, the UE performs only cell selection in performing RRC connection re-establishment, and when selecting a suitable cell, initiates access in the cell. But for remote UEs the procedure of re-establishment should take into account the situation of surrounding existing candidate relay UEs. How a remote UE performs the RRC connection re-establishment procedure is a problem to be solved. Disclosure of Invention The present invention proposes a solution to the problem that how one remote UE performs the RRC connection re-establishment procedure is to be solved. According to an aspect of the present invention, there is provided a method performed by a user equipment, UE, which is a method of an RRC connection re-establishment procedure performed by the user equipment, UE, comprising the steps of: The UE triggers or starts an RRC connection reestablishment process; In the process of starting RRC connection reestablishment, the UE starts a timer T311 and performs cell selection or relay selection; In the case that the UE selects a suitable cell or the UE selects a suitable relay, the UE stops T311, where the suitable cell is a cell whose measurement value or level value satisfies the rule of cell selection, and the suitable relay is a relay whose measurement value or level value satisfies the rule of relay selection. In the above-described method performed by the user equipment, it is preferable that, The non-remote UE performs only cell selection; the far-end UE outside the coverage only performs relay selection; the remote UEs within coverage are able to perform cell selection and relay selection. In the above-described method performed by the user equipment, it is preferable that, The above UE capable of performing cell selection and relay selection is performed in the following order: Firstly, executing cell selection, and when the result of cell selection is that no suitable cell exists, executing relay selection; Performing relay selection first, and performing cell selection when the relay selection result is that there is no suitable relay, or The UE performs cell selection and relay selection according to the indication of the network side. In the above-described method performed by the user equipment, it is preferable that, The indication of the network side received by the UE is carried in a reconfiguration message, which also carries information for handover or synchronization to the target relay or target cell. In the above-described method performed by the user equipment, it is preferable that, The indication information directly indicates the UE to only perform cell selection, or only perform relay selection, or perform cell selection first and then relay selection, or perform relay selection first and then cell selection, or perform relay selection first and then relay selection second The indication information is information for assisting the UE in determining the order or sequence in which to perform cell selection and relay selection. In the above-described method performed by the user equipment, it is preferable that, The UE determines the priority of performing relay selection and cell selection according to the received reconfiguration message carrying the information of handover or synchronization to the target relay or target cell. In the above-described method performed by the user equipment, it is preferable that, The UE stops T311 if a suitable relay is selected and a PC5 connection is established with it, which includes the following two cases: The UE selects a suitable relay first, but no PC5 connection has been established between the UE and the selected suitable relay, then the UE stops T311 after establishing a PC5 connection with the relay; the UE determines one of the relays with which a PC5 connecti