Applying SIP VoIP to Context-Aware Telephony

The simple, efficient Session Initial Protocol (SIP) is widely used to integrate context-awareness computing techniques. We propose a SIP-based research framework that integrates automatic speech generation to make communication between users more convenient. Based on the proposed approach, we built and tested a SIP context server and several SIP agents hosted on PCs. If the called party is absent or busy, a contextaware message is automatically replied to the caller via synthesized natural speech. Experiments conducted by 50 college students using ADSL connected to the SIP server showed encouraging results, especially in user satisfaction in message transfer rates and service waits.