Handover RCH Index Synchronization via Broadcast MAP

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Solution Overview

Problem

In wireless communication systems, handover processes often result in RCH identification mismatches between Base Stations (BS) and Mobile Stations (MS) due to unicast allocation of RCHs, leading to potential malfunctions as other MSs within the same BS index RCHs sequentially without knowing the allocation information of the unicast RCH.

Innovation Solution

The method involves transmitting a HandOver CoMmanD (HO-CMD) message that includes the RCH index and subframe index of the allocated RCH, ensuring the index does not overlap with existing RCHs, allowing both BS and MS to identify the RCH using the same index, thereby preventing index collisions and ensuring correct RCH usage during handover.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If unicast allocation is used to assign RCH to handover MS, then the handover MS can receive dedicated RCH allocation information, but other MSs within the same BS cannot receive information about the allocated RCH, leading to index mismatch

Engineering Contradiction:

Improvehandover reliabilityVSAvoidRCH allocation information visibility

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The RCH allocation information is segmented into two parts: dedicated unicast information for the handover MS and broadcast information for other MSs. The BS transmits the RCH index to the handover MS via unicast HO-CMD message, while simultaneously including the same RCH index in broadcast MAP messages so that all other MSs can also receive and synchronize to the same RCH allocation information.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The broadcast MAP message acts as an intermediary that carries the RCH index information to all MSs within the BS. This intermediary mechanism ensures that while the handover MS receives dedicated unicast notification, all other MSs also receive the same RCH allocation information through the broadcast channel, preventing index mismatch.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If RCHs are indexed sequentially by BS and MS independently, then each can manage its own RCH resources, but index mismatch occurs between BS and MS due to lack of shared allocation information

Engineering Contradiction:

Improveindependent RCH managementVSAvoidRCH index synchronization

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system implements feedback by having the BS broadcast the RCH index allocation information to all MSs through MAP messages. This feedback mechanism ensures that all MSs, including the handover MS and other MSs, receive the same RCH index information, enabling synchronized indexing and preventing mismatch between BS and MS.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The broadcast MAP message serves multiple functions: it provides resource allocation information for general uplink access and simultaneously conveys the specific RCH index allocated to the handover MS. This universal broadcast mechanism ensures all MSs have access to the same RCH indexing information, enabling consistent identification across the system.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9565607B2Method and apparatus for performing handover in a wireless communication system

Publication Date: 2017.02.07 SAMSUNG ELECTRONICS CO LTD

AI summary

An operating method of a serving Base Station (BS) in a communication system is provided). The method comprises transmitting a first message to a Mobile Station (MS), wherein the first message includes information related to a random access resource that is allocated to the MS by a target BS, and wherein the random access resource is distinguishable from other random access resources of the target BS.