IP Multimedia Subsystem was introduced by the Third Generation Partnership Project (3GPP) to enable 3G mobile systems to provide ubiquitous cellular access to all the services that the Internet provides, with improved Quality of Service, appropriate charging and integration of services. For users to access the IMS services, IMS capable User Equipments are required. In this paper we present an IMS Client compliant to 3GPP, European Telecommunications Standards Institute and Internet Engineering Task Force (IETF) specifications. Though some work has been done in the development of the IMS Client, such clients cannot be deployed in the mobile devices. Our IMS Client is developed under Java 2 Micro-Edition (J2ME) platform so it can be deployed in the mobile devices. The implementation and demonstration of the IMS Client on the IMS Testbed are presented. Our proposed IMS Client could perform the user registration and Instant Messaging communication.
