Method and apparatuses for making use of virtual ims subscriptions coupled with the identity of a non sip compliant terminal for non-registered subscribers

A Service Interaction Manager in a packet based multimedia system, the Service Interaction Manager being connected to a Network Access Gateway of a network in communication with the packet based multimedia system, wherein a terminal connected in the network requests a service in the packet based multimedia system, but the terminal does not have a subscription in the packet based multimedia system, the Service Interaction Manager comprising:

• a Table of Virtual Subscriptions for storing temporary virtual subscriptions;
• a Coupling Function connected with the Network Access Gateway and the Table of Virtual Subscriptions, wherein the Coupling Function is configured to utilize the Table of Virtual Subscriptions to couple an available virtual subscription to a terminal identifier of the terminal and store in the Table of Virtual Subscriptions, a temporary association between the terminal identifier and the available virtual subscription;
• and
• a Correlation Function connected with the requested service, the Table of Virtual Subscriptions, and a packet based multimedia system access gateway, wherein the Correlation Function is configured to:
• receive a session start request message from the packet based multimedia system access gateway, the session start request message including the terminal identifier;
• and
• utilize the Table of Virtual Subscriptions to correlate the session start request message with the available virtual subscription based on the terminal identifier received in the session start request message.