3G Inter-Domain Handover via SIM Toolkit SMS
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Solution Overview
Problem
Current 3G network architectures, such as the 3GPP Release 99 architecture, fail to enable seamless inter-domain handovers during active call sessions, resulting in disrupted connectivity when mobile terminals roam between different domains.
Innovation Solution
The method involves a mobile terminal registered in a Home domain transitioning to a Visited domain and potentially a New-Visited domain, using UMTS SIM Application Toolkit control messages sent via SMS to authenticate and negotiate resource allocation, ensuring continuous voice traffic routing through the Home domain GMSC, even as the Visited domain radio signal weakens, employing protocols like MAP, NAS-Sig, and ISUP for signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mobile terminal uses current 3GPP Release 99 architecture for domain registration, then the terminal can be registered in Visited domain through roaming agreements, but seamless inter-domain handover during active call sessions cannot be achieved
Solution Approach 1:
The mobile terminal performs preliminary authentication with the New-Visited domain before the actual handover occurs. The terminal initiates authentication procedures in advance when detecting a new domain, ensuring credentials are validated and resources are prepared before the handover is triggered, thus maintaining connectivity during the transition.
Solution Approach 2:
The Home domain GMSC acts as an intermediary to coordinate the handover process. It receives authentication requests from the New-Visited domain, validates them against the HLR, and manages the resource allocation between domains. This intermediary facilitates seamless handover by mediating the complex interactions between multiple domain entities.
2Adaptability or versatility
If the mobile terminal roams from Visited domain to another domain during active call, then the terminal can access new domain coverage, but connectivity to Home domain is lost and sessions are disrupted
Solution Approach 1:
The authentication and resource allocation procedures are designed to continue seamlessly during the handover process. The mobile terminal maintains its registration status across domains through continuous authentication validation, and voice traffic is re-routed without interruption by keeping the GMSC involvement active throughout the transition.
Solution Approach 2:
Resource allocation negotiation between Home domain and New-Visited domain operators is performed in advance before the handover is executed. This preliminary resource preparation ensures that when the handover occurs, the necessary resources are already allocated and ready, preventing session disruption.
3Ease of operation
If the mobile terminal triggers handover when Visited domain radio signal becomes low, then the terminal can maintain communication quality, but resource allocation coordination complexity increases
Solution Approach 1:
The mobile terminal autonomously monitors its own radio signal quality and independently triggers the handover procedure when thresholds are breached. The terminal initiates authentication with the New-Visited domain without requiring external prompting, simplifying the overall control architecture while maintaining communication quality.
Solution Approach 2:
The Home domain GMSC serves as an intermediary that automates the resource allocation negotiation process. It handles the complex coordination with New-Visited domain operators, managing service level agreement validations and resource reservations, thereby reducing the perceived complexity for the mobile terminal.
Data Source
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AI summary
The present invention provides a method for seamless mobility across 3G networks on different domains. 3G to 3G seamless inter-domain handovers invention extents the implementation currently running in standardized 3G network nodes.