IMRN Allocation for CS-to-IMS SIP Call Routing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In communication networks, when a UE device in the circuit-switched domain attempts to make a SIP call to an IP-only subscriber, it may fail if the packet-switched network is unavailable or does not support VoIP, as the device can only handle E.164 number-based calls in this domain.
Innovation Solution
The system dynamically allocates an IP multimedia routing number (IMRN) from a pool maintained by an application server in the IMS network, maps it to the called party's SIP URI, and uses this IMRN for routing the SIP call, ensuring the IMRN remains valid through timer mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a UE device in the circuit-switched domain attempts to make a SIP call to an IP-only subscriber, then the device can only handle E.164 number-based calls, but the call fails when the packet-switched network is unavailable or does not support VoIP
Solution Approach 1:
The patent introduces an IP multimedia routing number (IMRN) as an intermediary that bridges the circuit-switched domain and IP-only subscribers. The IMRN acts as a temporary routing address that allows CS-domain devices to reach SIP-based IP subscribers without requiring direct SIP protocol support or packet-switched network availability. The application server maintains a mapping between IMRNs and SIP URIs, enabling indirect routing through the circuit-switched network.
Solution Approach 2:
The system dynamically changes the routing parameter from a static E.164 number-only approach to a dynamic IMRN-based approach. The IMRN is temporarily assigned from a pool of available numbers, mapped to the target SIP URI, and used only for the duration of the call setup. This parameter transformation enables the CS device to communicate with IP subscribers by converting the SIP URI destination into a CS-compatible routing number.
2Adaptability or versatility
If the system maintains a pool of IMRNs for dynamic allocation, then call routing flexibility improves, but system complexity increases
Solution Approach 1:
The application server automatically manages the IMRN pool without requiring manual configuration or intervention. The system self-services by dynamically allocating IMRNs from the pool when needed, mapping them to SIP URIs, and releasing them back to the pool after use. Timer mechanisms automatically validate and expire IMRN assignments, and the system self-regulates the pool composition based on usage patterns, reducing the need for external management complexity.
Data Source
AI summary
In one embodiment, a scheme is disclosed for effectuating a call in a network environment including a circuit-switched (CS) network and an IP multimedia subsystem (IMS) network. Call information associated with a call is sent from a user equipment (UE) device to an application server (AS) node disposed in the IMS network. The call information includes at least one of a call reference number and a called party's URI. When a message is received at the UE device from the AS node, which message includes the call reference number and an IP multimedia routing number (IMRN), the returned call reference number is verified that it remains valid based on a local timer mechanism associated with the UE device. The IMRN is then sent to the application server in order to facilitate a session with respect to the called party.