Design of a Hybrid Router for Bridging Heterogeneous Embedded IP Networks in Ambient Intelligence Applications

Connection of wireless sensor and actuator networks (WSANs) to the Internet will enable information flow to these once isolated networks. Distributed Ambient Intelligence (AmI) applications, such as remote monitoring and control services, would become possible if Internet connectivity of WSANs is achieved. However, realization of such applications remains challenging with three major obstacles. First, the homogeneity of embedded sensor and actuator nodes and hence homogeneous networks prevents seamless information flow and service provision. Second, current WSAN technology has limited support for Internet connectivity. Protocol conversion with heavy overhead is required on a more powerful gateway device. Third, there are no common interoperable interfaces between different WSAN standards which has become a barrier to heterogeneous WSAN applications. This paper introduces a design for an integrated IP compatible, heterogeneous WSAN composed of the University of Auckland's AWSAM and Oracle's Sun SPOT nodes. This was achieved through the creation of a Hybrid Router, which physically bridges AWSAM and Sun SPOT communication with customized network abstraction, and an Edge Router, which provides Internet connectivity.