ECODA: enhanced congestion detection and avoidance for multiple class of traffic in sensor networks

Congestion in a Wireless Sensor Network (WSN) can cause missing packets, low energy efficiency, and long delay. Moreover, some applications, e.g. multimedia and image, need to transmit large volumes of data concurrently from several sensors. These applications have different delay and QoS requirements. Congestion problem is more urgent in such applications. To address this challenge, we propose a novel energy efficient congestion control scheme for sensor networks, called ECODA (Enhanced congestion detection and avoidance) which comprises three mechanisms: (1) Use dual buffer thresholds and weighted buffer difference for congestion detection; (2) Flexible Queue Scheduler for packets scheduling; (3) A bottleneck-node-based source sending rate control scheme. Simulations show that ECODA achieves efficient congestion control and flexible weighted fairness for different class of traffic. Therefore it leads to higher energy efficiency and better QoS in terms of throughput, fairness, and delay.