UbiGate: a gateway to transform discovery information into presence information

Pervasive computing involves various entities which need to coordinate tasks and share resources through different service discovery protocols. However, the multiplicity and the incompatibility of those protocols have made interconnectivity problematic. Moreover, most service discovery protocols require a strong participation of users to genuinely play their part. Consequently, service discovery in a pervasive environment has become a challenge that researchers as well as practitioners have tried to overcome through various approaches. Nevertheless, existing solutions mostly consist of designing new protocols which usually address specific application needs while participating in the increase of heterogeneity. To address these problems, we present a new paradigm for service discovery involving the use of a gateway, called UbiGate, and relying on SIP, a widespread signaling protocol. Centered around the notion of presence, UbiGate enables real time availability of service information while hiding the heterogeneity of underlying protocols. We have developed a prototype of UbiGate supporting service discovery protocols such as the protocol used in Bluetooth service discovery mechanism and a protocol enabling the detection mechanism of RFID. Preliminary results show that UbiGate enables new service discovery protocols, either IP or non-IP based, to be seamlessly supported with no significant overhead in discovery latency.