Indoor seamless roaming for VoIP using IPv6 location assisted network
In this paper, we present an approach to estimate the location of mobile unit in an indoor WiFi network environment. The estimated location information is then used to perform seamless session mobility across devices (i .e. device switching) in an IPv6 network. Prototype implementation of such location-assisted device switching has been develop ed and experimented. The proposed location estimation approach is based on the received Signal Strength Indicator (RSSI), to calculate an accurate Path Loss Exponent for a triangulation- based location estimation function. Results showed that our approach achieved an average error of 1.07m in an area of 10x10m. We have also monitored the detailed SIP and RTP messages exchanges for the device switching process to verify our prototype execution.
Based on the study of SIP,the paper presents the overlay method to implement the mapping between SIP protocol state machine and IN call state model BCSM,and analyses the implementation concretely.The method has resolved the key technology in interworking of Internet and IN.