Energy-Aware Real-Time Opportunistic Routing for Wireless Ad Hoc Networks

Existing studies on the design of routing protocols for wireless ad hoc networks mainly focused on energy efficiency. However, in many real-time applications such as target tracking and bush fire surveillance, latency is an important concern, and little attention has been paid to it in the design of routing protocols for such applications to meet the specified Quality of Service (QoS) requirements like the end-to-end latency constraint. In this paper we propose an energy-aware, opportunistic routing protocol EARTOR for requests with QoS constraints, through striking the elegant balance between the energy consumption and the end-to-end latency. Our objective is to maximize the number of requests realized when dealing with a sequence of requests arrived one by one. The core techniques adopted include the cross-layer design that incorporates the duty cycle, a bidding mechanism for each relay candidate that takes its residual energy, location information, and relay priority into consideration. We finally conduct experiments by simulations to evaluate the performance of the proposed protocol against existing ones, in terms of the dynamic delivery ratio and the network capacity. The experimental results demonstrated that the proposed protocol outperforms the state-of-the-art protocols significantly.