Random Access Across Multiple Uplink BWPs to Reduce Contention

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Solution Overview

Problem

In the 5G mobile communications system, there is a high probability of random access failures due to contention conflicts among terminal devices accessing a cell, as they receive the same random access configuration information and compete for uplink bandwidth parts (BWP), leading to increased access delays.

Innovation Solution

The terminal device sends random access preambles on multiple uplink BWPs within a single random access process, allowing it to perform random access on multiple BWPs, reducing contention conflicts by increasing access opportunities and selecting appropriate BWPs based on signal quality or load balancing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If terminal devices use the same random access configuration information to access the cell, then the network side device can broadcast system messages efficiently, but contention conflicts occur between terminal devices leading to random access failures

Engineering Contradiction:
Improverandom access success rateVSAvoidcontention conflict probability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent divides the uplink bandwidth into multiple bandwidth parts (BWPs), each with its own random access configuration information. This segmentation allows terminal devices to be distributed across different BWPs, reducing the probability that multiple devices select the same BWP for random access, thereby reducing contention conflicts and improving random access success rate.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each bandwidth part is configured with specific random access parameters including preamble resources and time-frequency locations that are unique to that BWP. This local quality differentiation ensures that terminal devices accessing different BWPs experience different random access conditions, reducing the likelihood of simultaneous access conflicts.

Inventive Principle:
Principle #3Local quality

2Productivity

If terminal devices perform random access on multiple uplink BWPs, then random access opportunities increase and contention conflicts decrease, but the complexity of the random access process increases

Engineering Contradiction:
Improverandom access opportunityVSAvoidrandom access process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The network side device pre-configures multiple bandwidth parts with their respective random access configuration information in system messages before terminal devices need to access the network. This preliminary configuration allows terminal devices to select appropriate BWPs for random access without requiring complex real-time negotiation or configuration, thereby reducing the complexity burden on terminal devices while still providing multiple access opportunities.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3829257B1Communication method and device
Publication Date: 2025.07.23 HUAWEI TECH CO LTD
  • EP3829257B1 patent drawingFigure 1~2
  • EP3829257B1 patent drawingFigure 3
  • EP3829257B1 patent drawingFigure 4

AI summary

This application provides a communication method and a device, to reduce a probability of a random access failure caused when a contention conflict occurs in a random access process of a terminal side device in a mobile communications system. In this solution, any terminal side device in the mobile communications system can send random access preambles on N uplink BWPs to a network side device in one random access process, so that the terminal side device can perform random access on a plurality of uplink BWPs, thereby increasing a random access opportunity of the terminal side device. In this method, because the network side device or each terminal side device may subsequently perform random access on any one of the N uplink BWPs, this method can reduce a phenomenon that a contention conflict occurs between each terminal side device and another terminal side device in a random access process, thereby improving a success probability of random access of each terminal side device.