Context-aware communication services a framework for building enhanced IP telephony services

Communication is an essential part of our daily life. A multitude of devices enable users to communicate everywhere and anytime. One drawback resulting from this ability is the expectation of a caller to always reach the callee. As a consequence the possibility to restrict "availability for communication" becomes a necessary feature too. Users demand efficient filtering mechanisms to control incoming calls according to their current context. Communication services should become more user centric and consider context information to adapt to the most suitable behavior. This paper investigates the use of context information to enhance existing SIP call control services and services created with the call processing language (CPL). These context-aware communication services are the proposed approach to cope with the demand for a user centric control of incoming calls. The proposed solutions have been implemented as an extended SIP call control service and an extension to the existing CPL syntax. Currently, location information forms the primary source of context information. Different indoor location sensing systems have been evaluated. Finally, two different kinds of service types have been chosen for evaluation as representatives for the variety of service creation approaches especially in a SIP environment