In many settings, the users are mobile (e.g. away from their desks) while high quality multimedia telephony equipment has fixed locations. This may result in unsuccessful multimedia calls and motivates a context aware system which supports session mobility. This paper aims to address these issues.
The approach is to utilize state‐of‐the‐art in‐context awareness and integrate this into a real time telecom system based on SIP. System requirements are formulated and the system is designed, implemented and (technically) tested.
The paper contains a thorough analysis of why baseline SIP and SIP REFER alone cannot solve our case and why a new SIP extension is introduced. The solution is evaluated and compared to solutions such as “virtual terminals”.
It is pointed out that the context model does not directly support roaming between two different business domains. This issue is however of limited impact in an enterprise setting. The current prototype is thoroughly tested from a technical viewpoint, but user studies in real organizations are recommended as further work.
The paper shows that human issues and issues relating to computer mediated communication (CMC) are strongly linked to technical details in SIP. In practice this means that researchers in CMC and CSCW should look more into building prototypes where real time conversational features are supported together with dynamic change of media types.
The main value of the paper is a thorough described technical realization of the context aware multimedia application ENriched MEdia (ENME). The background material and the appendix should be of value to anyone interested in convergence between computing and communication.
