WTRU DRX Cell Reselection Triggering

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Solution Overview

Problem

Current wireless communication systems lack defined DRX behavior for WTRUs during cell reselection, radio link failures, and transitions between DRX and CRX modes, leading to potential message loss and inefficient resource management.

Innovation Solution

A method and apparatus enabling cell reselection for WTRUs in DRX mode by configuring triggers to disable or enable DRX operation based on specific events, such as RNTI availability, cell reselection, and radio link failures, ensuring continuous reception during critical events and efficient resource management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If DRX operation is used to reduce interference and battery consumption, then energy efficiency improves, but the WTRU may miss critical signaling messages during cell reselection and radio link failure recovery

Engineering Contradiction:

Improvebattery consumptionVSAvoidmessage receipt reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements dynamic switching between DRX and continuous reception modes based on the WTRU's operational state. The WTRU transitions from DRX mode to continuous reception mode when initiating cell reselection or recovering from radio link failure, ensuring critical messages are received while maintaining energy efficiency during normal operation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the reception parameter from discontinuous to continuous based on specific triggers. When the WTRU detects cell reselection needs or radio link failure, it modifies its reception behavior parameter to ensure continuous monitoring of downlink channels, thereby receiving critical signaling without losing energy efficiency during stable operation

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the WTRU switches to continuous reception during cell reselection, then message receipt reliability improves, but energy consumption increases

Engineering Contradiction:

Improvemessage receipt reliabilityVSAvoidbattery consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent segments the reception operation into distinct phases: DRX mode during normal operation and continuous reception mode during critical events (cell reselection, radio link failure recovery). This segmentation allows the WTRU to maintain energy efficiency while ensuring reliable message receipt during essential procedures

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent prepares for critical events by having the WTRU switch to continuous reception mode before attempting to receive critical messages. By proactively changing the reception state upon detecting cell reselection needs or radio link failure, the WTRU ensures it is ready to receive signaling without missing important messages

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP2654352B1Method and apparatus for enabling cell reselection for WTRU operating in discontinous reception

Publication Date: 2017.11.22 INTERDIGITAL PATENT HOLDINGS INC

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AI summary

A method for discontinuous reception (DRX) implemented in a wireless transmit/receive unit (WTRU) during cell reselection including initiating cell reselection; disabling DRX operation, wherein disabling DRX operation enables continuous reception; transmitting a CELL UPDATE message; receiving a CELL UPDATE CONFIRM message; and enabling DRX operation based on the received CELL UPDATE CONFIRM message.