SRVCC Handover Signaling Optimization via Capability Forwarding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the context of SRVCC handovers, the target radio access network element fails to correctly learn whether the user is allowed to use SRVCC, leading to incorrect triggering of handovers, resulting in failures and interruptions of voice services due to excessive signaling waste.
Innovation Solution
A method where the source mobility management network element sends a forward relocation request message with SRVCC capability information to the target mobility management network element, enabling it to notify the target radio access network element about the user's SRVCC capability and support, ensuring correct SRVCC handover operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the target mobility management network element does not receive SRVCC capability information from the source, then the signaling exchange is simplified, but the SRVCC handover fails because the target radio access network element cannot correctly learn whether SRVCC operation may be performed
Solution Approach 1:
The source mobility management network element performs preliminary action by including SRVCC capability information in the forward relocation request message before the handover execution. This ensures that the target mobility management network element and subsequently the target radio access network element have the necessary information to correctly perform SRVCC operations, preventing handover failures.
Solution Approach 2:
The forward relocation request message serves as an intermediary carrier that transfers SRVCC capability information from the source mobility management network element to the target mobility management network element. This intermediary mechanism ensures accurate information transmission without requiring direct communication between all network elements.
2Productivity
If the target radio access network element incorrectly triggers SRVCC handover without proper capability information, then the handover can be initiated, but this results in SRVCC handover failure and interruption of voice service
Solution Approach 1:
The target mobility management network element uses the received SRVCC capability information as feedback to determine whether to allow SRVCC operations. This feedback mechanism prevents incorrect triggering of SRVCC handover by ensuring that the target radio access network element only performs SRVCC operations when the user is confirmed to be allowed to use SRVCC, thereby maintaining voice service continuity.
Solution Approach 2:
The SRVCC capability information is provided in advance through the forward relocation request message, enabling the target radio access network element to make informed decisions about handover initiation. This preliminary information prevents incorrect triggering while maintaining efficient handover execution.
3Reliability
If SRVCC capability information is transmitted through the forward relocation request message, then correct SRVCC handover execution is ensured, but the signaling overhead increases
Solution Approach 1:
The SRVCC capability information is merged into the existing forward relocation request message rather than being transmitted as a separate message. This combining approach ensures that the necessary information is included for accurate SRVCC operation while minimizing additional signaling overhead by utilizing an already-required message structure.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The embodiments of the present invention disclose a handover method and a mobility management network element. The method includes: a target mobility management network element receives a forward relocation request message sent by a source mobility management network element, where the forward relocation request message includes single radio voice call continuity SRVCC capability information; and the target mobility management network element sends, to an target access network element, a first request message that carries information of SRVCC operation possible. The present invention also provides a corresponding mobility management network element. The embodiments of the present invention provide a handover method and a mobility management network element. The source mobility management network element indicates whether the target mobility management network element is SRVCC capable through the forward relocation request, which enables the target mobility management network element to correctly indicate that the target radio access network network element is SRVCC capable, and enables the target radio access network network element to correctly trigger an SRVCC handover, and saves network's signaling exchanges, and ensures correct usage of a user's voice service.