Abstract

Services are the main driving forces of the Telecommunication industry. In old days the traditional networks e.g. PSTN and mobile cellular networks provide basic services to customers such as voice call, SMS. Unlike mobile cellular networks, Internet provides wide variety of services that allow users to communicate in different ways for example E-mail, WWW, VoIP, and Instant Messaging. To benefit from these Internet (IP) based services and to support new value-added services in mobile cellular networks, the IP Multimedia Subsystem (IMS) is defined. It aims at convergence of Internet and the cellular world. IMS introduced an architectural framework envisioned by telecom experts for providing wide variety of multimedia services for example Presence, Context-based applications, Conferencing, Video-on-Demand, Instant Messaging to name just a few. The main ingredients of these services are data which can be either provided by users or derived from external sources (other networks). In recent years, Wireless Sensor Networks have emerged as networks of tiny devices, sensor nodes. WSNs are characteristically different from existing networks. In general, a WSN is a data oriented network in which sensors sense physical environment and produce data to deliver it to interested applications. These applications are usually external to WSN and reside in an external network (e.g. IMS). The applications or services use this physical data to deliver enhanced services such as context-based services to mobile users. The challenge is to integrate WSN with IMS so that the WSN data can be accessible to IMS services or applications. This thesis exploits a presence-based approach for the integration of WSN and IMS network. A standard interface for data exchange between WSN and IMS has been devised in the Telecommunication Service Engineering group. The data exchange between WSN and IMS services/applications is realized as a publish-subscribe mechanism. In publish-subscribe mechanism the applications subscribe to WSN services (data) and get notified when sensors report any data while the WSN is acting as publisher to publish sensor data to IMS. The presence-based WSN -- IMS architecture provides an abstraction to services and applications for accessing variety of sensed data from different WSNs. The presence based WSN-IMS architecture realizes two main architectural entities, the integrated WSN-IMS gateway and an IMS extended presence server. These two architectural entities play a key role in interworking of WSN and IMS network. The overall architecture has been implemented and tested with prototype applications as well as a performance evaluation has been done to see the efficiency and applicability of the integrated architecture