IMS Contact Address Restoration via HSS Backup Check

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current procedures for restoring IMS services after an S-CSCF failure result in loss of restoration information, particularly when multiple contact addresses are registered, leading to inconsistencies and incorrect handling of re-registration and de-registration requests.

Innovation Solution

Modifying the handling of requests for re-registration and de-registration by the HSS and S-CSCF to check for existing registration data, preventing overwrite of backed-up information and ensuring accurate restoration and maintenance of contact address registrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the HSS overwrites restoration information during re-registration to update contact addresses, then the registration data is kept current, but previously backed-up contact information is lost

Engineering Contradiction:
Improveregistration data accuracyVSAvoidrestoration information
Core Design Contradiction:
Manufacturing precisionVSLoss of information

Solution Approach 1:

The HSS performs a preliminary check before overwriting restoration information to determine whether the contact address is new or already registered. This preliminary identification prevents loss of restoration information by only overwriting when appropriate, while preserving backed-up information for already-registered contacts.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the S-CSCF processes de-registration requests without checking for existing registration data, then the process is simple and fast, but restoration information is lost and services are incorrectly interrupted

Engineering Contradiction:
Improvede-registration processing speedVSAvoidservice restoration accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The S-CSCF implements a feedback mechanism by checking whether contact address registration data exists before processing de-registration requests. This feedback loop ensures that de-registration only proceeds when appropriate, preventing incorrect service interruption while maintaining efficient processing for valid de-registration cases.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If multiple contact addresses are registered for a single IMPI/IMPU combination, then the system supports multiple access networks and IP addresses, but restoration after S-CSCF failure becomes complex and error-prone

Engineering Contradiction:
Improvemulti-contact registration capabilityVSAvoidrestoration procedure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system segments contact address management by maintaining separate registration records for each contact address while linking them to the parent IMPI/IMPU combination. This segmentation allows multiple contacts to be managed independently, simplifying restoration procedures after failure by enabling selective re-registration of individual contacts rather than managing all contacts as a single complex unit.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2351335B1IMS restoration procedures for multiple contacts
Publication Date: 2016.06.08 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2351335B1 patent drawingFigure 1
  • EP2351335B1 patent drawingFigure 2
  • EP2351335B1 patent drawingFigure 3

AI summary

In one aspect, the invention provides a method, and associated apparatus for re-registering a contact address of a user of an IP Multimedia Subsystem, IMS, network. A request for re-registration of the contact address is recevied at a Serving-Call Session Control Function, S-CSCF, node serving the user. After a determination that the S-CSCF has no stored information relating to the contact address, a request is sent to a Home Subscriber Server, HSS, of the user to register the contact address information. The HSS detects if the contact address information relating to the user has already been backed-up by the HSS, and notifies the node serving the user of registered contact address information backed-up by the HSS. Another aspect provides a method and associated apparatus for de-registering a registered contact address of a user of an IP Multimedia Subsystem, IMS, network.