A Converged IMS Client for the IP Multimedia Subsystem

The IP Multimedia Subsystem (IMS) has been developed to provide a single platform that offers many different converged services, over multiple access technologies, with several different end user terminals. It aims to unify the current disjoint point solutions offered by network operators, with the goal of reducing CAP-EX (Capital Expenditure), OP-EX (Operating Expenditure) as well as reducing the time taken to develop a new service. These benefits are realised by the move to a single, IP-based packet switched network. However, the IMS framework has not been adopted as widely as first envisaged, due to a lack of a “killer” application i.e. a service that will see wide use and will drive IMS adoption. There is a need to improve the service creation environment and encourage more developers to begin looking at IMS services if the IMS is to reach its full potential. This paper will discusses the design and implementation of a new IMS client for converged services. It explains the motivation behind the work, the design decisions made, the client architecture as well as the surrounding framework necessary to implement the proposed functionality. More specifically, it describes an implementation of an IMS client that supports instant messaging, status mechanisms for handling presence and voice and video calling, with the aim of providing a fully featured example client that can be used as a starting point for further research and to develop new services.