Context information processing for system-unaware communications

This paper describes the design and implementation of a ubiquitous networking server that enables cross-device as well as cross-network mobility by using an out-of-band signaling method with a location sensing system for context-aware seamless network services. The context includes the user's presence, position of the user and neighboring devices, network interfaces attached to the mobile terminal, availability and available bandwidth of each network, priority in selecting networks, capabilities of the mobile terminal and devices, and installed applications. The server is designed to be placed not in operators' networks but in users' local networks such as home and enterprise networks to provide users with mobile IP-based handover capability between radio networks in a distributed manner. This would accelerate the introduction of Mobile IP to network services, offering flexibility in creating human-centric network services. The out-of-band signaling method we propose exchanges information between mobile terminals and the network about user and device authentication, session initiation protocol (SIP) signaling, mobile IP signaling, the position of users and devices, and signaling for cross-device mobility. These features provide us unprecedented flexibility in communication