Building multicluster 802.15.4 networks: issues and open problems

The 802.15.4 communication standard is being increasingly used in wireless sensor networks, thanks to industry-wide support it has enjoyed in recent years. However, its support for bridging and building multicluster networks is still minimal, and a number of open issues preclude its even wider usage in practice. In this article we highlight the most important aspects of building multicluster 802.15.4 networks, review some of the design alternatives for implementing the bridging function, and discuss their pertinent properties in terms of ease of scheduling, performance, scalability, and security.