Research And Implementation Of Instant Messaging Control Subsystem Based On Softswitch

Along with increase of requirements of various and integrated communication services and development of communication technologies, NGN, short for Next Generation Networks, is proposed. NGN is an integrated, open and new network in the telecommunication industry. Its key features are convergence, open and service driven. And it could provide many kinds of services, such as voice, data, multimedia services and so on. Softswitch is one of key entities in NGN, providing functions of switch control and supporting for services.Instant messaging (IM), short message in mobile system (SMS) and message part in Open Services API are all services related to message, and have many aspects in common. With low cost and nearly real time communications, these services become more and more important in NGN. So it is necessary for Softswitch to provide basic ability of instant messaging, which is a typical message service.However, many instant messaging systems are designed for Internet. So it becomes an important problem that how to design an instant messaging system for Softswitch, which fits for NGN and supports ability of short message as well as ability of message part in Parlay API. And this is the key issue discussed and solved in this paper.There are three innovations in this paper:First of all, different kinds of protocols used to implement instant messaging (IM) system are compared with each other, and this paper chooses SIMPLE protocol as a suitable protocol to implement IM system based on Softswitch system.Second, it is proposed that how to design instant messaging system supported by reusing abilities in Softswitch system. In this paper, instant messaging system is implemented based on SIMPLE protocol and there are two main models in SIMPLE which can be used to design IM system, so how to design IM system in session model and in pager model out of session are both discussed here.Third, a control subsystem in instant messaging system is designed. And this subsystem can be used to support basic abilities of instant messaging, short message in mobile network and message part of in Parlay interface.In the end of this paper, it is also described that how to implement the control subsystem in instant messaging system, as well as how to test it.