A fault-tolerant backbone for IEEE 802.15.4 based networks

IEEE 802.15.4 is a well-accepted standard for realizing wireless control networks. Besides the immediate use by an application, many industrial automation and building automation technologies are based on this standard. However, wireless networks have significant drawbacks. One major drawback is the range, since many automation systems are spread over a wide area or are even located in different facilities. In some cases, gateways are used to bridge the wireless clusters. However, a gateway strongly depends on the application. This paper introduces a transparent backbone for seamless communication in IEEE 802.15.4. The proposed solution is capable of connecting a large number of wireless clusters. The concept does not depend on a specific backbone medium. It only requires a pairwise connection among all backbone nodes. Thus, any fieldbus protocol or even Ethernet (IP) can be used. Since many applications are safety-critical, the backbone allows placing two or more wireless interfaces in one cluster and tolerates faults of backbone devices.