Event Reporting with Fairness in Wireless Sensor Networks

Fairness in wireless sensor networks demands event nodes to have an equal share in the overall throughput of the system. Fairness is difficult to achieve in sensor networks due to multiple hop packet forwarding to a single destination that results in congestion. Moreover, greater the density of event region greater is the level of interference and greater is the number of packet drops. In this paper, we present a mechanism for fair event reporting that is implemented at the transport layer. The solution encompasses congestion control and fair rate adjustment schemes based on hop-by-hop packet delivery and buffer size. Moreover, a schedule based packet forwarding policy is used at the transport layer for ordered delivery of packets to the underlying layer; instead of commonly used jittered forwarding. The simulation results of our scheme shows high per node fair throughput from multiple event nodes to a single sink. Also, the use of our schedule-based packet forwarding policy helps to avoid packet collisions and increases the packet delivery ratio even from densely populated event regions.