Low overhead loop-free routing in wireless sensor networks

We consider the crucial problem of routing in wireless sensor networks. Routing protocols need to deal with topology changes while keeping the routing overhead low, especially the number of broadcasts, to save energy. In this paper, we consider the problem of building and adapting default routes for convergecast and host routes for downward traffic. We first propose a local repair scheme that allows arbitrarily long periods for rebuilding the tree/DODAG of default routes. Second, we design a scheme for preventing packet forwarding along routing loops, which may occur in the combination of broken host routes and default routes. We achieve this goal without adding an additional header to packets. The two schemes along with on-demand host route construction provides a complete routing solution that addresses many of the shortcomings of RPL. We validate the proposed schemes with Cooja emulations and an experimental evaluation on a real-world sensor network testbed.