Geographical cluster based routing in sensing-covered networks

The relationship between coverage and connectivity in sensor networks has been investigated in recent research treating both network parameters in a unified framework. It is known that networks covering a convex area are connected if the communication range of each node is at least twice a unique sensing range used by each node. Furthermore, geographic greedy routing is a viable and effective approach providing guaranteed delivery for this special network class. In this work we show that the result about network connectivity does not suffer from generalizing the concept of sensing coverage to arbitrary network deployment regions. However, dropping the assumption that the monitored area is convex requires the application of greedy recovery strategies like traversing a locally extracted planar subgraph. A recently proposed variant performs message forwarding along edges of a virtual overlay graph instead of using wireless links for planar graph construction directly. However, there exist connected network configurations where this routing variant may fail. In this work we proof a theoretical bound which is a sufficient condition for guaranteed delivery of this routing strategy applied in sensing covered networks. By simulation results we show that this bound may also be relaxed from a practical point of view and that geographical cluster based routing achieves a comparable performance compared to other planar graph routing variants based on two-hop neighbor information.