Automatic originator regulation of IMS multiple traffic by stateless signaling prioritization

In emergent situations such as an earthquake, huge traffic from multiple services pours into IP Multimedia Subsystem (IMS) network and leads to a severe congestion problem. To protect IMS network, telecom companies usually take a measure of originator regulation on voice calls. However existing solutions are unable to maximize the service throughput for handling multiple services. This paper proposes an automatic originator regulation of IMS multiple traffic by stateless signal prioritization based on the types, message order and retransmissions of SIP messages within each call session. The best prioritization is to give a higher priority to a message type appearing at a later stage in each session and a lower priority to a retransmitted message. We also show the optimum queue length. For the effective confirmation of the safety at a disaster, an ideal communication system should pass more light-weight messages like instant messaging (IM) than those generated by voice calls. The simulation result shows the maximum throughput for each multimedia service is kept as in this ideal model even in an extremely congested situation with the 60 times larger offered load than usual which was observed in the 2011 earthquake off the Pacific coast of Tohoku.