A Power Aware and Real Time Routing Protocol for Wireless Sensor and Actor Networks

Wireless Sensor and Actor Networks (WSANs) comprises of a group of distributed sensors and actors that communicate through wireless links. Sensors are small and static devices with limited power, computation, and communication capabilities responsible for observing the physical world. Actors are equipped with richer resources, able to move and perform appropriate actions. There are three specific challenges in WSAN: delivery of the event detection report to the actor within the specified delay, energy constrains of the sensor nodes and the reliable delivery of the sensed report. In this paper we propose a real-time, energy aware, routing protocol. Our protocol works in three phases, first phase is route creation. In RREQ control packet the information such as route, remaining power, average traffic and current time are embedded. At the destination, the route with the maximum remaining power is chosen for transmission. In the maintenance phase, if any intermediate link fails, then RREQ process takes place. The third and final phase is route deletion phase. In this phase, if the remaining power of a route is below a threshold, then the route is removed from the routing table. While sending a packet, the node calculates the current remaining power of the route using the previously received packets from that route. If the current remaining power is below a threshold, then the route is not chosen for transmission, the node tries with other route or starts new route establishment process. In our protocol, the intermediate nodes forward the packet based on the deadline associated with them, this makes it suitable for real time nature of WSAN. We evaluate performance of our protocol through extensive simulations and have been found to outperform Ad hoc On Demand Distance Vector (AODV) and Greedy Rumor Forwarding Routing (GRFR) protocols in terms of packet delivery ratio, deadline miss ratio, and lifetime of the network without much of overhead.