Multi-mode UE Accessibility via Combined Location Area Update
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Solution Overview
Problem
In the prior art, user accessibility is compromised due to the implicit detach timer expiring in the MSC/VLR, leading to incorrect identification of the user as inaccessible, even when they are within the network coverage, resulting in failed call or SMS services.
Innovation Solution
A method and multi-mode terminal solution where the UE initiates an update process to the MSC/VLR upon expiration of the TAU periodic timer, specifically by initiating a combined routing area/location area update in network mode I and a LAU in network mode II/III, to reactivate the Gs interface and restart periodic timers, ensuring user accessibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the implicit detach timer in MME expires while no update message is received from the terminal, then the network element sets the user in implicit detach state to save resources, but this causes the user to be incorrectly identified as inaccessible even when within network coverage
Solution Approach 1:
The terminal proactively initiates a periodic location area update before the network's implicit detach timer expires, ensuring the network element resets its timer and maintains the user in an accessible state. This preliminary action prevents the harmful outcome of incorrect accessibility identification while allowing the network to save resources by avoiding unnecessary paging.
2Use of energy by moving object
If the terminal does not initiate periodic update when residing in GSM/UMTS network with activated ISR, then the terminal saves power and reduces signaling, but the periodic TAU timer in LTE module expires without triggering update
Solution Approach 1:
The initiating module acts as an intermediary that monitors the periodic TAU timer from the LTE module and triggers a location area update in the GSM/UMTS network when the timer expires. This intermediary function ensures that power is not wasted on continuous updates while maintaining reliable network accessibility by triggering updates only when necessary.
3Reliability
If the UE initiates combined routing area/location area update to reactivate Gs interface, then user accessibility is ensured, but the device complexity and signaling overhead increase
Solution Approach 1:
The solution merges the routing area update and location area update into a single combined update process. This allows the terminal to reactivate the Gs interface and ensure user accessibility in the circuit switched network while reducing the number of separate signaling transactions required, thereby lowering overall signaling overhead and processing complexity.
Data Source
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AI summary
The disclosure discloses a method for realizing user accessibility and a multi-mode terminal. A UE initiates, after a tracking area update (TAU) periodic timer of the UE expires, an update process to a mobile switching center/visitor location register (MSC/VLR) in the case that an idle mode signaling reduction (ISR) is activated and the UE resides in a global system for mobile communications/universal mobile telecommunication system (GSM/UMTS). The disclosure improves user experience.