Call Loop Avoidance in Wireless Network Location Updates
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Solution Overview
Problem
Current wireless communication networks face issues with call loops forming during mobile terminated calls when a mobile device is in the process of location updating, leading to incomplete call delivery and network resource inefficiencies.
Innovation Solution
Implementing a method and apparatus that prevent call loops by determining, based on gateway MCME indications, whether a call loop is expected during a location update procedure, and using enhanced call routing procedures to route calls directly from the new MCME to the mobile device, thereby avoiding the old MCME.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the network routes the MT call to the old MCME during location update, then the call can be delivered using existing routing procedures, but a call loop forms causing network resource waste and call delivery failure
Solution Approach 1:
The patent applies preliminary action by checking whether a location update is in progress before routing the MT call. The GMSC queries the HLR to determine if the mobile device is undergoing location update, and based on this advance knowledge, decides not to route the call through the old MCME, thereby preventing the call loop from forming in the first place
Solution Approach 2:
The HLR serves as an intermediary that provides routing information and location update status to the GMSC. The HLR enables the GMSC to make informed routing decisions by indicating whether the mobile device is currently updating its location, thus preventing the GMSC from routing calls that would create call loops
2Device complexity
If the network performs standard routing through old MCME during location update, then routing procedures remain simple, but network resources are wasted due to call loop signaling
Solution Approach 1:
The system performs a preliminary check at the HLR to determine if a location update is in progress before the call routing decision is made. This advance information allows the GMSC to bypass the old MCME and route the call directly to the new MCME, avoiding unnecessary signaling and reducing network resource consumption without significantly increasing routing complexity
3Productivity
If the call is routed through the old MCME during location update, then the existing call routing mechanism works, but call setup time increases due to call loop delays
Solution Approach 1:
The HLR performs a preliminary query to determine the mobile device's location update status before the GMSC attempts to route the call. This preliminary action provides the GMSC with accurate routing information in advance, enabling direct routing to the new MCME and eliminating the time-consuming call loop that would otherwise occur
Data Source
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AI summary
A call loop avoidance capability is provided for preventing formation of a call loop resulting from handling of a mobile terminated (MT) call in parallel with a location update for a mobile device (MD) in a wireless communication network. The call loop avoidance capability prevents formation of a call loop between an old mobility and call management entity (MCME) and a new MCME when delivery of an MT call to an MD is performed while the MD is in the process of moving from the old MCME to the new MCME using a location update procedure. An enhanced call routing procedure supports direct delivery of the MT call from the new MCME to the MD (rather than delivery of the MT call by the new MCME to the MD via the old MCME) in order to prevent formation of a call loop between the old MCME and the new MCME.