Network Handover IP Address Retention Mechanism
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Solution Overview
Problem
In network handover scenarios, ensuring service continuity is challenging due to the uncertainty of maintaining the same Packet Data Network (PDN) gateway and IP addresses between different networks, such as 3GPP and non-3GPP networks.
Innovation Solution
A method and apparatus for network handover that involves sending a message with distinct identifiers to determine and allocate the same IP address for a user equipment across different networks, ensuring continuity by identifying and replicating the first IP address used in the initial network during the handover process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the TWAN uses the default APN to establish the PDN connection, then the PDN connection can be established in the non-3GPP network, but it cannot be ensured that the same PDN gateway and IP address are used as in the 3GPP network, resulting in service discontinuity
Solution Approach 1:
The UE includes the first IP address and first distinct identifier in the handover message before actually handing over to the non-3GPP network. This preliminary inclusion of IP address information allows the target gateway to pre-configure the same IP address for the second PDN connection, ensuring service continuity without requiring additional acquisition procedures after handover.
Solution Approach 2:
The patent implements a feedback mechanism where the UE provides information about the first IP address and first distinct identifier from the 3GPP network to the non-3GPP network during handover. The target gateway device uses this feedback information to allocate the same IP address for the second PDN connection, creating a closed-loop system that ensures IP address consistency across network boundaries.
2Adaptability or versatility
If multiple PDN connections are established with different gateway devices, then network connectivity is improved, but it becomes difficult to maintain the same IP address across different networks, increasing device and network burden
Solution Approach 1:
The patent uses the concept of copying by including the first IP address information in the handover message and having the target gateway device copy or replicate this IP address for the second PDN connection. This copying approach allows the UE to maintain the same IP address across different networks and gateway devices, significantly reducing IP address management complexity while preserving multi-network connectivity.
3Reliability
If the network allocates a new IP address during handover, then IP address uniqueness is maintained, but additional IP address acquisition procedures are required, degrading user experience
Solution Approach 1:
The UE performs the preliminary action of including the first IP address and first distinct identifier in the handover message before the handover completes. This allows the target gateway to pre-allocate or pre-configure the same IP address for the second PDN connection, eliminating the need for additional IP address acquisition procedures after handover and significantly reducing the time loss that would otherwise occur.
Data Source
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AI summary
A method and an apparatus for network handover are provided, which are capable of ensuring service continuity after a network handover. This method includes: sending a first message that includes first information to a second network, where the first information is used to indicate that a user equipment needs to be handed over from a first network to the second network, so that a target gateway device allocates, to the user equipment according to at least the first information sent by the second network, a second IP address that is the same as a first IP address and used when a second packet data network PDN connection is established by using the second network and the target gateway device, where the first IP address is an IP address used when the user equipment establishes a first PDN connection by using the first network and the target gateway device. The gateway device obtains the first IP address used when the user equipment establishes a PDN connection by using the first network, and allocates, to the user equipment, the second IP address that is the same as the first IP address and used when a PDN connection is established by using the second network. Therefore, service continuity is ensured after a network handover.