Reserved Code Handoff Access for Wireless Collision Reduction

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Solution Overview

Problem

In cellular wireless communication systems, handoff access procedures face challenges such as collisions during random access, leading to delayed or failed connections due to the inability to distinguish between terminals, especially in shared channel systems like LTE, where precise timing and resource reservation are complex and inefficient.

Innovation Solution

A method and device for handoff access using a reserved character code, where a source BS requests a target BS to allocate a reserved character code and random access sub-channel to a mobile terminal, preventing collisions by ensuring unique access and reducing delay through pre-allocated sequence numbers and sub-channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If terminals acquire wireless channel resources at the target BS in a competitive random access manner, then the system complexity is reduced, but handoff access delay increases and collision probability increases

Engineering Contradiction:
Improvesystem complexityVSAvoidhandoff access delay
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The target BS pre-allocates dedicated random access resources (character codes and time slots) to the mobile terminal during the handoff preparation stage. This preliminary assignment eliminates the need for competitive random access at the handoff moment, thereby reducing access delay and collision probability while maintaining reasonable system complexity.

Inventive Principle:
Principle #10Preliminary action

2Loss of time

If the target BS reserves shared wireless channel resources in advance, then handoff access delay is reduced, but wireless channel utilization efficiency decreases

Engineering Contradiction:
Improvehandoff access delayVSAvoidwireless channel utilization efficiency
Core Design Contradiction:
Loss of timeVSProductivity

Solution Approach 1:

Instead of reserving resources globally in advance, the system performs dedicated resource allocation locally and dynamically for each handoff event. The target BS allocates specific character codes and time slots to individual terminals based on real-time handoff requirements, ensuring resources are reserved only when needed and released afterward, thus maintaining high channel utilization efficiency while reducing handoff delay.

Inventive Principle:
Principle #3Local quality

3Reliability

If the target BS reserves shared wireless channel resources, then handoff access reliability is improved, but resource reservation complexity increases

Engineering Contradiction:
Improvehandoff access reliabilityVSAvoidresource reservation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The handoff resource allocation process is integrated into the existing handoff signaling procedure. The source BS initiates the handoff request, the target BS automatically allocates resources and returns the allocation information through standard handoff signaling, and the mobile terminal executes the handoff using the received resource information. This self-service mechanism ensures reliable handoff access without requiring complex external resource reservation management.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2068582B1A handoff access method and device based on random access channel
Publication Date: 2016.01.13 ZTE CORP
  • EP2068582B1 patent drawingFigure 1~2
  • EP2068582B1 patent drawingFigure 3
  • EP2068582B1 patent drawingFigure 4~5

AI summary

A handoff access method and device based on a random access channel is provided, the method comprising: a source BS sends a handoff request message to a target BS; the target BS sends a handoff response message to the source BS, and then the source BS forwards a handoff command with the content of the handoff response message to the mobile terminal, wherein a sequence number of a reserved character code allocated by the target BS to the mobile terminal and a random access sub-channel that the reserved character code is located in are contained in the handoff command message; after receiving the handoff command message, the mobile terminal selects the reserved character code and the random access sub-channel that the reserved character code is located in; and a handoff access procedure is initialized on the random access sub-channel by the target BS and the mobile terminal.