Random access method, user terminal and base station

Abstract

The embodiment of the invention provides a random access method, a user terminal and a base station, and the method comprises the steps: receiving system information, and obtaining a UL / SUL selection threshold and a random access selection parameter carried in the system information; determining a link for executing random access based on the UL / SUL selection threshold; determining a competitive random access mode based on the random access selection parameter; executing a related random access process on the link according to the competitive random access mode, wherein the competitive random access mode is specifically a two-step competitive random access mode or a four-step competitive random access mode. According to the embodiment of the invention, under each 5G cell, for the UE supporting two-step and four-step random access at the same time, the UE can select a proper random access carrier and mode under the condition of network side control, so that the success rate of random access is increased, and the network access delay is reduced.

Description

technical field [0001] The present invention relates to the technical field of communication, and more specifically, to a random access method, a user terminal and a base station. Background technique [0002] In the 5G system, in addition to the traditional four-step random access process, a two-step random process is introduced in order to shorten the network access delay of the terminal. [0003] The four-step contention random access process is as follows: figure 1 As shown, it includes: Step 100, UE initiates a random access process, selects a contention preamble and PRACH resource position, and sends the preamble preamble on the selected PRACH resource position, and this message is called msg1; Step 101, The network receives and successfully decodes the preamble code sent by the UE, and returns a random access response message (called msg2) to the UE. The msg2 contains the preamble ID in step 100, as well as the timing advance command, uplink transmission authorizatio...

AI Technical Summary

Problems solved by technology

[0005] Some terminals in the 5G system are required to support two contention random access methods (two-step contention random access and four-step contention random access) at the same time. Research on selecting an appropriate random access method. Therefore, it is urgent to provide a mechanism to enable the UE to select an appropriate carrier and random access method when initiating random access, so as to improve the success rate of random access and reduce random access. access delay

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