Design of a SIP-based real-time visitor conversation and door control architecture using a home gateway

Though typical video door phone systems can be used to talk to the visitors at the door, they have some shortcomings: the resident should stay in house and he/she is not informed of any visitor information on his/her return to home. To overcome these limitations, we propose an architecture supporting user mobility, with which the resident at anywhere can view and converse with a visitor at the front door using PCs, PDA´s and home servers with Internet connections. We implemented the proposed architecture using SIP (session initiation protocol) and a home gateway system connected to a conventional intercom or a video door phone system.