PRACH Resource Segmentation for Beam Failure Recovery

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Solution Overview

Problem

In 5G New Radio systems, fast beam failure recovery is hindered because network nodes cannot determine when a channel or signal for transmitting a beam failure recovery request is configured for terminals, leading to inefficient link recovery mechanisms.

Innovation Solution

Configuring a Physical Random Access Channel (PRACH) resource for terminals to reserve specific resources for beam failure recovery requests, which are orthogonal to those used for normal random access procedures, ensuring persistent availability and reducing signaling overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If beam failure recovery request is transmitted through multiple channels or signals, then recovery capability is improved, but network complexity and signaling overhead increase

Engineering Contradiction:
Improvebeam failure recovery capabilityVSAvoidnetwork signaling complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the random access resources into dedicated PRACH resources for beam failure recovery requests and normal random access resources. This segmentation allows the network to handle beam failure recovery separately from normal access procedures, improving recovery reliability without significantly increasing overall network complexity since the resources are already allocated and organized in distinct categories.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary action by pre-configuring dedicated PRACH resources for beam failure recovery requests before beam failure occurs. The network node allocates and configures these resources in advance through RRC signaling, so that when beam failure happens, the terminal can immediately use the pre-prepared resources without needing to request or negotiate resources during the critical recovery moment, thus improving recovery speed and reliability while avoiding additional signaling during failure events.

Inventive Principle:
Principle #10Preliminary action

2Speed

If dedicated PRACH resources are pre-configured for beam failure recovery, then recovery speed is improved, but resource allocation complexity increases

Engineering Contradiction:
Improvebeam failure recovery speedVSAvoidresource configuration complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent applies universality by designing the dedicated PRACH resource configuration to serve multiple purposes: it functions as both normal random access resources and beam failure recovery resources. The same configured PRACH resources can be used by terminals for both regular access procedures and for transmitting beam failure recovery requests, eliminating the need for completely separate resource sets and reducing overall configuration complexity while maintaining fast recovery capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses parameter changes by modifying the configuration parameters of existing PRACH resources to indicate their dual functionality. Through RRC signaling, the network configures PRACH resources with specific parameters that identify them as suitable for beam failure recovery, allowing the same physical resources to be dynamically allocated for different purposes based on configuration parameters rather than requiring physically separate resource pools.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If beam failure recovery uses shared resources with normal random access, then resource utilization is improved, but recovery reliability decreases

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidbeam failure recovery reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent segments the usage rights of PRACH resources through configuration signaling. While the physical PRACH resources remain shared, the network configures specific resources as dedicated for beam failure recovery through RRC signaling, creating logical separation. This segmentation ensures that when a terminal needs to transmit a beam failure recovery request, it uses the configured dedicated resources, guaranteeing that these resources are available and not contested by normal random access procedures, thus maintaining high reliability while preserving resource sharing efficiency.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3644640B1Methods for a terminal and for the peer network device for the configuration and for the release of random access resource, the related terminal, and the related network device
Publication Date: 2023.05.17 VIVO MOBILE COMM CO LTD
  • EP3644640B1 patent drawingFigure 1~4
  • EP3644640B1 patent drawingFigure 5~6

AI summary

A method of configuring a random access resource, a terminal, and a network node are provided. The method includes: receiving configuration information of a physical random access channel PRACH resource transmitted by a network node; wherein the configuration information is configured to indicate a PRACH transmission resource reserved by the network node for the terminal and used to transmit a beam failure recovery request.