Random access method and apparatus, and electronic device

Patent metadata

Field	Value
Publication number	US-12593359-B2
Application number	US-202118260551-A
Country	US
Kind code	B2
Filing date	Jan 6, 2021
Priority date	Jan 6, 2021
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

A random access method includes: determining a trigger source for 2-STEP random access; and according to the trigger source for the 2-STEP random access, triggering 2-STEP random access correspondingly; where triggering 2-STEP random access includes: determining that the trigger source is beam failure recovery (BFR) for secondary cell and there are no available uplink resources, and triggering the 2-STEP random access to request the available uplink resources.

First claim

What is claimed is:

1 . A random access method, comprising:
determining a trigger source for 2-STEP random access; and according to the trigger source for the 2-STEP random access, triggering 2-STEP random access correspondingly; wherein triggering 2-STEP random access comprises: determining that the trigger source is beam failure recovery (BFR) for a secondary cell and there are no available uplink resources; and triggering the 2-STEP random access to request available uplink resources; wherein triggering 2-STEP random access comprises one of the following: determining that the trigger source is BFR for a primary cell and/or BFR for a primary secondary cell, and obtaining a network configuration of user equipment; and determining that the network configuration includes allowance of triggering 2-STEP random access when BFR for the primary cell is triggered and/or BFR for the primary secondary cell is triggered, and triggering 2-STEP random access for beam recovery; or determining that the trigger source is a regular buffer status report (BSR) and determining that there are no available uplink resources or failure of present available uplink resources to meet logical channel prioritization (LCP) mapping restriction of a logical channel, and triggering 2-STEP random access to request available uplink resources; or determining that the trigger source is a scheduling request (SR) and there are no available uplink resources, and triggering 2-STEP random access to obtain available uplink resources; or determining that the trigger source is small data transmission (SDT), and obtaining data radio bearer (DRB) that triggers the SDT; and determining that a network configuration of user equipment includes the DRB or a logical channel corresponding to the DRB being configured with 2-STEP random access or hybrid automatic repeat request (HARQ) with uplink (UL) retransmission disabled, and triggering 2-STEP random access for SDT; or determining that the trigger source is SDT, and obtaining a network configuration of user equipment; and determining that the network configuration includes allowance of the user equipment to trigger 2-STEP random access in inactive state, and triggering 2-STEP random access for SDT; wherein the random access method further comprises: obtaining a bandwidth part (BWP) selected by user equipment to initiate random access; determining that the BWP is configured with 2-STEP random access resources, obtaining reference signal received power (RSRP) for downlink path loss reference of the BWP, obtaining RSRP threshold corresponding to the trigger source which triggers 2-STEP random access, determining that the RSRP is greater than or equal to the RSRP threshold and initiating 2-STEP random access; or determining that the BWP is not configured with the 2-STEP random access resources, and initiating 4-STEP random access.

2 . The random access method according to claim 1 , wherein the available uplink resources comprise at least one of the following:
available uplink resources for sending BFR media access control layer control element (MAC CE); available uplink resources for sending truncated BFR MAC CE; or available uplink resources with UL retransmission of corresponding HARQ not disabled.

3 . The random access method according to claim 1 , wherein the random access method further comprises:
determining that the network configuration indicates contention free random access (CFRA) resources for BFR; obtaining a type of the CFRA resources for BFR; and triggering 2-STEP random access based on the type of the CFRA resources for beam recovery.

4 . The random access method according to claim 1 , wherein the random access method further comprises:
determining that the network configuration includes allowance of triggering 2-STEP random access when BFR for the primary cell is triggered and/or BFR for the primary secondary cell is triggered, and the network configuration indicates contention free random access (CFRA) resources for BFR; obtaining a type of the CFRA resources for BFR; and triggering 2-STEP random access based on the type of the CFRA resources for beam recovery.

5 . The random access method according to claim 1 , wherein triggering the regular BSR comprises at least one of the following:
the network side being configured with a logical channel for 2-STEP random access; the network side being configured with a logical channel of HARQ with UL retransmission disabled; the network side being configured with a low-latency logical channel, wherein the logical channel is a traffic channel and/or a control channel; and the network side being configured to allow user equipment to use 2-STEP random access; wherein the network configuration of user equipment is activated or deactivated through MAC CE or physical downlink control channel (PDCCH); wherein the random access method further comprises: determining that there are a plurality of regular BSRs and types of random access triggered by the plurality of regular BSRs are different, and selecting one type from a plurality of types to initiate random access; or determining that there are a plurality of regular BSRs and types of random access triggered by the plurality of regular BSRs are different, selecting the regular BSR triggered by the logical channel with a highest priority from the plurality of regular BSRs, and initiating random access based on a random access type triggered by the selected regular BSR.

6 . The random access method according to claim 1 , wherein determining that there are no available uplink resources and triggering 2-STEP random access to obtain available uplink resources comprises:
determining that there are no the scheduling request resources, and obtaining the trigger source for the SR; determining that the trigger source for the SR is the regular BSR triggered by a logical channel for 2-STEP random access configured on the network side, or the regular BSR triggered by a logical channel which uses HARQ with UL retransmission disabled and is configured on the network side, or the BFR for the secondary cell, and triggering 2-STEP random access to request the available uplink resources; wherein the network configuration of user equipment is activated or deactivated through MAC CE or PDCCH.

7 . The random access method according to claim 1 , wherein determining that there are no available uplink resources and triggering 2-STEP random access to obtain available uplink resources comprises:
determining that there are no the scheduling request resources, and obtaining the network configuration of user equipment; and determining that the network configuration includes allowance of the SR to trigger 2-STEP random access, and triggering 2-STEP random access to obtain the available uplink resources; wherein the network configuration of user equipment is activated or deactivated through MAC CE or PDCCH.

8 . The random access method according to claim 1 , wherein determining that the network configuration of user equipment includes the DRB or a logical channel corresponding to the DRB being configured with 2-STEP random access or HARQ with UL retransmission disabled, and triggering 2-STEP random access for SDT comprises:
determining that there are a plurality of DRBs triggering the SDT; obtaining the DRB with a highest priority; determining that the network configuration of the user equipment includes the DRB with the highest priority or a logical channel corresponding to the DRB with the highest priority being configured with 2-STEP random access or HARQ with UL retransmission disabled; and triggering 2-STEP random access for SDT.

9 . A random access method, comprising:
receiving a 2-STEP rand

Assignees

• Beijing Xiaomi Mobile Software Co Ltd

Inventors

• Jiang Xiaowei

Classifications

• H04W74/04

  Scheduled access (hybrid access H04W74/02) · CPC title

• H04W76/19 Primary

  Connection re-establishment · CPC title

• H04W74/0836

  with 2-step access · CPC title

• H04W74/006

  in the downlink, i.e. towards the terminal · CPC title

• H04W74/004

  in the uplink, i.e. towards network · CPC title