Mobile Station EPC-MO-LR Support Detection CS Fallback

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Solution Overview

Problem

In mobile communication systems, the lack of clear conditions for performing CS Fallback when a mobile station in the E-UTRAN scheme uses MO-LR results in increased positioning delays, even when EPC-MO-LR is supported, and network operators cannot effectively instruct the positioning service implementation.

Innovation Solution

The mobile communication method determines EPC-MO-LR support through specific network capability indicators in Attach or TAU Accept messages, allowing the mobile station to decide on CS Fallback and switch between E-UTRAN and UTRAN schemes based on support availability, thereby optimizing positioning service usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the mobile station performs CS Fallback process to use MO-LR in UTRAN scheme, then positioning service can be provided, but positioning delay is increased

Engineering Contradiction:
Improvepositioning service availabilityVSAvoidpositioning delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The network performs preliminary action by including positioning support indication in NAS messages (ATTACH/TAU ACCEPT) before the mobile station initiates positioning requests. This allows the mobile station to know in advance whether EPC-MO-LR is supported, preventing unnecessary CS Fallback and reducing positioning delay.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network provides feedback to the mobile station about positioning support capability through positioning support indication in NAS messages. This feedback mechanism enables the mobile station to make informed decisions about which positioning method to use, avoiding unnecessary system switching and reducing delay.

Inventive Principle:
Principle #23Feedback

2Loss of time

If the mobile station uses EPC-MO-LR in E-UTRAN scheme without CS Fallback, then positioning delay is reduced, but the condition for selecting positioning method is not clearly defined

Engineering Contradiction:
Improvepositioning delayVSAvoidpositioning method selection clarity
Core Design Contradiction:
Loss of timeVSEase of operation

Solution Approach 1:

The network performs preliminary action by including positioning support indication in NAS messages (ATTACH/TAU ACCEPT) before the mobile station initiates positioning requests. This allows the mobile station to know in advance whether EPC-MO-LR is supported, preventing unnecessary CS Fallback and reducing positioning delay.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network provides feedback to the mobile station about positioning support capability through positioning support indication in NAS messages. This feedback mechanism enables the mobile station to make informed decisions about which positioning method to use, avoiding unnecessary system switching and reducing delay.

Inventive Principle:
Principle #23Feedback

3Device complexity

If the network does not provide positioning support indication, then the system is simpler, but the mobile station cannot make informed decisions about positioning service usage

Engineering Contradiction:
Improvesystem complexityVSAvoidpositioning service decision-making
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The network performs preliminary action by including positioning support indication in NAS messages (ATTACH/TAU ACCEPT) before the mobile station initiates positioning requests. This allows the mobile station to know in advance whether EPC-MO-LR is supported, preventing unnecessary CS Fallback and reducing positioning delay.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network provides feedback to the mobile station about positioning support capability through positioning support indication in NAS messages. This feedback mechanism enables the mobile station to make informed decisions about which positioning method to use, avoiding unnecessary system switching and reducing delay.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2498559B1Mobile communication method and mobile station
Publication Date: 2018.05.16 NTT DOCOMO INC
  • EP2498559B1 patent drawingFigure 1
  • EP2498559B1 patent drawingFigure 2
  • EP2498559B1 patent drawingFigure 3

AI summary

A mobile station UE according to the present invention includes a control unit 12 configured, upon determination based on "EPC-MO-LR support" included in "Attach Accept" or "TAU Accept" received from a mobility management node MME that "EPC-MO-LR" is not supported in a mobile communication system of an E-UTRAN scheme, to switch the E-UTRAN scheme to a UTRAN scheme after establishing a connection in the mobile communication system of the E-UTRAN scheme, and then transmit "NAS MO-LR Request" to a mobile switching center SGSN/MSC.