Session Transfer Identification in IMS Using Device Identifiers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the IMS domain of communications networks, there is a lack of clear methods for the SCC AS control node to identify the session to be transferred when a user has multiple sessions sharing the same public user identity across different devices, leading to ambiguity in session control and continuity.
Innovation Solution
The method involves storing session information with unique identifiers such as MSISDN, IMSI, and GRUU for each user device in the CS domain, comparing these identifiers in session transfer requests to determine the specific session to be transferred, and using these identifiers to facilitate session control and continuity, particularly through the SCC AS, MSC server, and MME nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a user shares a public user identity among multiple devices, then service versatility and user convenience are improved, but session identification accuracy deteriorates
Solution Approach 1:
The patent segments the identification process by introducing device-specific identifiers (MSISDN, IMSI, GRUU) that distinguish individual devices within the same user identity group. Each device is assigned a unique identifier that can be used to correlate session transfer requests with the correct ongoing session, thereby maintaining identification accuracy while allowing multiple devices to share a user identity.
Solution Approach 2:
The patent introduces an intermediary correlation mechanism in the SCC AS that matches device-specific identifiers from session transfer requests with stored session information. This intermediary process enables accurate session identification by bridging the gap between shared user identities and unique device identifiers, allowing the system to resolve which specific session should be transferred.
2Measurement precision
If device-specific identifiers are stored and compared for session transfer, then session identification accuracy is improved, but control node complexity increases
Solution Approach 1:
The patent applies preliminary action by storing device-specific identifiers (MSISDN, IMSI, GRUU) in advance during session establishment. This pre-stored information is readily available when a session transfer request occurs, eliminating the need for complex real-time identification processes and reducing the complexity of the session transfer procedure itself.
Solution Approach 2:
The patent changes the identification parameter from shared user identity to device-specific identifiers during session transfer. By switching to these unique parameters, the system achieves accurate session identification without requiring complex algorithms, as the matching process becomes a straightforward parameter comparison between stored identifiers and request identifiers.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to session control in an IMS domain of a communications network and more particularly to techniques for performing session transfer in an IMS control node (SCC AS) for controlling centralized services in an IMS domain. One embodiment of an SCC AS (200) may be adapted to store, for each of a plurality of ongoing communication sessions, a session information item (218) comprising a user identity (222) identifying a user device involved in the session and a first identifier (216) of the user device in a CS domain of the communications network, wherein the user identity is associated with multiple user devices and the first identifier comprises at least one of an MSISDN (216), an IMSI, and a GRUU.