IMS Session Resurrection via Security Association Mapping
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Solution Overview
Problem
IMS sessions are frequently terminated due to connectivity interruptions, causing users to lose their active calls and requiring them to re-establish new sessions, which is inconvenient and inefficient in terms of network resources.
Innovation Solution
The technique involves mapping a new security association to an active IMS session using an updated IP address after a connectivity interruption, allowing the IMS session to remain active and be reconnected without requiring the user to re-establish a new session, by utilizing network components to maintain the IMS bearer and update the security association with the new IP address.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a mobile device switches access networks or experiences connectivity interruption, then the device can maintain mobility and access different networks, but the security association is lost and the IMS session is terminated
Solution Approach 1:
The network component stores the IMS session information and security association parameters in advance before connectivity interruption occurs. When the mobile device reconnects with a new IP address, the network component retrieves the stored session information and re-establishes the security association using the new IP address, avoiding complete session termination.
Solution Approach 2:
A network component acts as an intermediary between the mobile device and the IMS core network. This intermediary maintains the security association and session state, allowing it to translate between the old and new security contexts when the device changes IP addresses, thereby preserving session continuity across network switches.
2Reliability
If the IMS session is re-established after connectivity interruption, then the security association can be updated with new IP address, but the user experience is degraded due to call termination
Solution Approach 1:
The IMS session and security association are maintained continuously by the network component even during connectivity interruptions. When the mobile device reconnects, the session is resumed without termination, allowing the useful action of ongoing communication to continue seamlessly without requiring user intervention to re-initiate calls.
Solution Approach 2:
The security association parameters, specifically the IP address, are dynamically updated to reflect the device's new network location while maintaining the core session state. This parameter change allows the security association to remain valid across different network configurations without requiring complete re-establishment of the session.
3Reliability
If a new IMS session is initiated after connectivity interruption, then the security association can be re-established, but network resources are wasted due to session re-establishment
Solution Approach 1:
Instead of discarding the IMS session and security association when connectivity is interrupted, the network component preserves this information in storage. Upon device reconnection, the session is recovered and reactivated, avoiding the need to re-establish the entire session and associated security context, thereby conserving network resources.
Data Source
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AI summary
The techniques described herein are configured to map a new security association to an active Internet Protocol (IP) Multimedia Subsystem (IMS) session subsequent to the occurrence of a connectivity interruption. In various examples, the connectivity interruption occurs in an access network that supports an IMS network. The new security association is established using an updated IP address that is configured for (e.g., assigned to) a mobile device after the connectivity interruption to the IMS session occurs. The techniques described herein improve network performance because less resources are spent to establish new IMS session in response to the interruption. Rather, in accordance with the examples provided herein, network components can determine that a new security association is associated with an active IMS session, and the network components can map the new security association to the active IMS session (e.g., one for which the IMS has not released the IMS bearer).