LIPA Handover Connectivity Checks to Prevent Resource Waste
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Solution Overview
Problem
Handover failures in mobile communication systems, particularly in Local Internet Protocol Access (LIPA) scenarios, result in wastage of signaling and wireless resources due to unsuccessful handovers between base stations connected to different Local Gateways (LGWs), leading to inefficient resource utilization.
Innovation Solution
A method and source base station implementation that determine whether a target base station connects with the user plane node serving the source base station before initiating handover, releasing resources if not connected, thereby preventing resource waste by deactivating LIPA bearers proactively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If handover is performed between base stations connected to different Local Gateways, then mobility service is provided, but handover failure occurs and signaling resources are wasted
Solution Approach 1:
The source base station determines whether the target base station connects with the same user plane node before initiating handover. This preliminary check prevents handover failures by identifying incompatible target base stations in advance, ensuring that handover is only attempted when the target connects to the same Local Gateway as the source, thus maintaining handover reliability while preserving mobility service
2Device complexity
If handover is attempted without checking user plane node connectivity, then handover procedure is simple, but signaling and wireless resources are wasted due to handover failure
Solution Approach 1:
The source base station performs a connectivity check between the target base station and the user plane node before initiating handover. This preliminary determination identifies whether the target base station connects to the same Local Gateway, preventing wasteful handover attempts and conserving signaling resources while adding minimal complexity to the handover procedure
3Ease of operation
If resources are released after handover failure, then handover procedure is standard, but resource utilization is inefficient
Solution Approach 1:
The source base station releases resources associated with the LIPA bearer before initiating handover when it determines that the target base station does not connect to the same user plane node. This proactive resource release prevents wasteful resource allocation during failed handover attempts, significantly improving resource utilization efficiency while maintaining standard handover procedures for successful cases
Data Source
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AI summary
Methods for avoiding handover failure are provided. The method includes transmitting first information indicating a local network identifier and second information indicating a local sub network; receiving third information indicating a local network identifier and fourth information indicating a local sub network; determining whether the first information and the third information are different, or whether the second information and the fourth information are different; determining to perform a handover of a user equipment, UE, from the source BS to the target BS; releasing resource for a local ip access, LIPA, connection of the UE, when the first information and the third information are different, or when the second information and the fourth information are different; and transmitting, to a source mobility management entity, MME, a handover request message including a closed subscriber group, CSG, ID of the target BS.