GSM Mobile Unit Disconnect Procedure for Channel Failure

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Solution Overview

Problem

In GSM voice calls, there is a significant delay in detecting and addressing downlink channel failures due to the combination of mobile unit and base station timeout procedures, which prolongs the time before users are notified of a dropped call and network resources are reallocated.

Innovation Solution

A method where a mobile unit detects downlink channel failures and sends disconnect messages to the base station, including prediction disconnect messages based on the likelihood of successful decoding of slow associated control channel blocks, to bypass the base station's timeout procedure, thereby reducing the time to tear down the communication and reallocate resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the mobile unit uses a timeout procedure to detect DL channel failure, then the mobile unit can determine when to stop transmitting, but the base station timeout procedure causes a significant delay in detecting and notifying call failure

Engineering Contradiction:
Improvechannel failure detectionVSAvoidcall failure notification time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The mobile unit performs preliminary action by proactively sending a disconnect message to the base station upon detecting DL channel failure, before the base station's timeout procedure completes. This preliminary notification eliminates the need for the base station to wait for its timeout timer to expire, significantly reducing the overall failure detection time.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the base station implements a timeout procedure to detect transmission cessation, then the base station can identify when the mobile unit stops transmitting, but the combined timeout procedures at both ends create unnecessary delay

Engineering Contradiction:
Improvetransmission status detectionVSAvoidnetwork resource reallocation speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The mobile unit provides feedback to the base station by sending a disconnect message that explicitly notifies the base station of the DL channel failure. This feedback mechanism allows the base station to immediately respond and reallocate resources without waiting for its timeout procedure to complete, thereby improving productivity while maintaining reliable detection.

Inventive Principle:
Principle #23Feedback

3Stability of the object's composition

If the mobile unit waits for the base station timeout procedure to complete before initiating disconnect, then the disconnect timing is coordinated, but the overall disconnect time is significantly prolonged

Engineering Contradiction:
Improvedisconnect procedure coordinationVSAvoiddisconnect duration
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The mobile unit takes preliminary action by sending the disconnect message as soon as it detects DL channel failure, before the base station's timeout procedure completes. This approach maintains coordination stability while significantly reducing the overall disconnect duration, as the base station can immediately process the disconnect request without waiting for its timeout timer.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2180752B1Method and system for disconnect procedure
Publication Date: 2012.08.08 MOTOROLA MOBILITY LLC
  • EP2180752B1 patent drawingFigure 1~2
  • EP2180752B1 patent drawingFigure 3
  • EP2180752B1 patent drawingFigure 4

AI summary

A method (300) and system (100) for a disconnect procedure. In one arrangement, the method (300) can include the step of - during a call at a mobile unit (120) operating in accordance with the GSM standard - detecting (302) a downlink channel failure between the mobile unit (120) and a base station (110). The method (300) can also include the step of - in response to the downlink channel failure detection - signaling (304) the base station (110) from the mobile unit (120) with a disconnect message. The disconnect message can be configured to prevent the base station (110) from unnecessarily undergoing a base station timeout procedure.