LTE Access Gateway Handover IP Address Mapping
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Solution Overview
Problem
In LTE networks, AG handover leads to fragmentation of routing table information, increasing route search time and affecting forwarding efficiency due to the need to update IP address segments in routers.
Innovation Solution
A service path changing method and apparatus that involves a mobility management entity determining and instructing a user equipment (UE) to switch from one access gateway (AG) to another, notifying the service peer end of a new IP address assigned by the second AG, thereby avoiding the need to update routing information in the router.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a UE is handed over from an old AG to a new AG and routing information is updated in the router, then the UE can communicate through the new AG, but routing table information becomes fragmented and route search time increases
Solution Approach 1:
The patent introduces an IP address mapping mechanism where the old IP address (from old AG) and new IP address (from new AG) are mapped to each other through a mapping relationship stored in the router. This intermediary mapping allows the router to forward packets destined for the old IP address to the new AG without fragmenting routing tables, thus reducing route search time while maintaining UE mobility handover capability
Solution Approach 2:
The patent changes the IP address parameter assignment strategy by allowing the UE to retain its original IP address from the old AG even after handover to a new AG. The mapping relationship between the old IP address and the new AG's network layer address enables the router to redirect traffic without requiring routing table updates, thereby preventing fragmentation and reducing route search time
2Adaptability or versatility
If routing information is updated in the router during AG handover, then downlink data can be routed to the new AG, but forwarding efficiency decreases due to routing table fragmentation
Solution Approach 1:
The patent introduces an IP address mapping mechanism where the old IP address (from old AG) and new IP address (from new AG) are mapped to each other through a mapping relationship stored in the router. This intermediary mapping allows the router to forward packets destined for the old IP address to the new AG without fragmenting routing tables, thus reducing route search time while maintaining UE mobility handover capability
Solution Approach 2:
The patent establishes IP address mapping relationships in advance before handover occurs. The mapping relationship between the old IP address and the new AG's network layer address is pre-configured or dynamically created prior to actual data forwarding, enabling the router to efficiently redirect traffic without requiring real-time routing table updates, thereby maintaining high forwarding efficiency during AG handover
Data Source
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AI summary
The present invention relates to the field of communications technologies, and in particular, to a service path changing method and apparatus, to resolve a problem that fragmentation of routing table information in a router is caused when a UE performs AG handover. The service path changing method in the present invention includes: determining, by an MME, that a UE needs to be handed over from a first AG to a second AG; and instructing, by the MME, the UE to notify, according to bearer information used to perform service transmission between the second AG and the UE and assigned by the second AG, a service peer end that an IP address of the UE is changed from a first IP address assigned by the first AG to a second IP address assigned by the second AG Because the second IP address assigned by the second AG exists in an IP address segment maintained by the second AG, it is not required to add the first IP address assigned to the UE by the first AG into the IP address segment maintained by the second AG, and it is unnecessary to change routing information of a router in a PDN to route downlink data of the UE to the second AG