Access Session Controller for IMS Signaling Simplification
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Solution Overview
Problem
The existing IMS network has a complex structure that results in prolonged and inefficient call signaling processing flows, especially during session establishment, due to excessive operations and increased delays when users are roaming.
Innovation Solution
An access session controller is introduced to simplify the signaling processing flow by directly routing call request messages between users within the same access session controller, reducing the need for multiple forwarding through P-CSCF and I-CSCF, and utilizing a network-wide home subscriber server system to manage user registration and authentication efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the existing IMS network structure is used for session establishment, then service functionality is provided, but the signaling processing flow becomes prolonged and complex
Solution Approach 1:
The patent extracts the session control function from the traditional P-CSCF/S-CSCF architecture and consolidates it into an Access Session Controller (A-SCCF) located at the access layer. This extraction simplifies the signaling flow by eliminating unnecessary intermediate nodes (P-CSCF, I-CSCF, S-CSCF) while maintaining service functionality, directly addressing the contradiction between providing comprehensive services and reducing session establishment time.
Solution Approach 2:
The patent merges multiple session control functions (P-CSCF, S-CSCF, I-CSCF) into a single Access Session Controller (A-SCCF) at the access layer. This consolidation combines the functions of call routing, service triggering, and session management into one unified controller, significantly reducing the number of signaling interactions and accelerating session establishment while maintaining full service capability.
2Ease of operation
If multiple forwarding through P-CSCF and I-CSCF is used, then call routing is achieved, but excessive operations increase processing complexity
Solution Approach 1:
The patent extracts the essential call routing function from the complex P-CSCF/S-CSCF/I-CSCF chain and implements it directly in the Access Session Controller (A-SCCF) at the access layer. This extraction maintains the core routing capability while eliminating the complexity of multiple forwarding operations, achieving simple signaling processing without sacrificing routing functionality.
Solution Approach 2:
The Access Session Controller (A-SCCF) is designed as a universal controller that performs multiple functions including call routing, service triggering, session management, and authentication. By making the A-SCCF multi-functional, the patent eliminates the need for separate specialized nodes (P-CSCF, S-CSCF, I-CSCF), thereby reducing network structure complexity while maintaining operational simplicity.
3Adaptability or versatility
If users are roaming in the network, then service accessibility is maintained, but signaling interactions increase and delay increases
Solution Approach 1:
The patent implements local quality by placing the Access Session Controller (A-SCCF) directly at the access layer where users connect, regardless of their location (home network or roaming network). This local deployment enables the A-SCCF to handle signaling locally without requiring complex interactions with home network S-CSCFs, thereby maintaining service accessibility for roaming users while significantly reducing signaling processing delay.
Solution Approach 2:
The Access Session Controller (A-SCCF) acts as an intermediary between the user equipment and the core network services. For roaming users, the A-SCCF mediates the signaling by locally handling authentication, service triggering, and session management, thereby reducing the need for direct interactions with the home network and minimizing signaling delay while maintaining full service accessibility.
Data Source
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AI summary
A local session controller, an IP multimedia subsystem, and a session registration method are presented. The local session controller comprises: an information receiving module, a service initiating and configuring module, a session control module, and an information transmitting module. The IP multimedia subsystem mainly comprises the local session controller and a home subscriber server of the whole network. The local session controller initiates an authentication request during the session registration period, processes the request from the subscribers directly, and then establishes the session. The above scheme can make the signaling processing simply and reduce the complexity of the network.