L-CAAF-n ICCF Address Acquisition for IMS Service Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In IMS networks, the Local-CS Access Adaptation Function Network (L-CAAF-n) lacks the ICCF address information for ICS users, preventing it from transforming SIP signaling and establishing association-control relations.
Innovation Solution
The L-CAAF-n acquires subscription information through MAP, SH, or Cx interface messages to determine if a user is an ICS user, and then obtains ICCF address information to establish association-control relations by notifying CS information to the ICCF, which provides its own address information in return.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If the L-CAAF-n independently deploys between UE and MSC, then the service control is centralized in IMS network, but the L-CAAF-n lacks ICCF address information to establish association-control relations
Solution Approach 1:
The patent introduces the S-CSCF as an intermediary entity that bridges the L-CAAF-n and ICCF. The S-CSCF receives the INVITE message from the L-CAAF-n, retrieves the ICCF address information from the HSS, and forwards the modified INVITE message to the ICCF. This intermediary mechanism enables the L-CAAF-n to establish association-control relations without directly storing ICCF address information, thus resolving the information loss problem while maintaining centralized service control.
2Adaptability or versatility
If the L-CAAF-n transforms CS signaling to SIP signaling, then the service control is unified in IMS domain, but the L-CAAF-n cannot send transformed SIP signaling without ICCF address information
Solution Approach 1:
The patent applies preliminary action by having the L-CAAF-n perform the signaling transformation from CS to SIP domain before reaching the ICCF. The L-CAAF-n transforms the CS signaling into SIP signaling and includes the user's current location information in the INVITE message. This preliminary transformation enables unified service control in the IMS domain while the subsequent retrieval of ICCF address information from HSS ensures the signal flow can be properly established.
3Adaptability or versatility
If different ICS users are routed to different ICCFs, then the service control is flexible, but the L-CAAF-n fails to acquire ICCF address information for new users
Solution Approach 1:
The patent makes the HSS a universal information source that serves multiple functions: it stores subscriber profile information, provides ICCF address information, and enables the L-CAAF-n to acquire necessary information for both existing and new ICS users. This universal approach ensures that the L-CAAF-n can reliably acquire ICCF address information for any user, maintaining routing flexibility while improving reliability of address information acquisition.
Data Source
AI summary
A method for establishing association-control relations includes these steps: An access adapting unit acquires subscription information of the user through a mobile application part (MAP) message, an SH interface message, or a Cx interface message; and acquires information indicating that the user is an ICS user from the subscription information of the user. A system, an access adapting unit, and an IMS CS control function (ICCF) for establishing association-control relations are also provided. In embodiments of the present invention, an access adapting unit such as a local-CS access adaptation function-network (L-CAAF-n) may know whether a user is an IMS centralized service (ICS) user and acquire the ICCF address information so that association-control relations may be established between the L-CAAF-n and the ICCF.