Enhancing DCCP-TCP-like mechanism for Wireless Sensor Networks

Congestion is a significant problem that faces streaming media applications in Wireless Sensor Networks (WSN). This problem occurs when the sensor receives traffic that exceeds its maximum forwarding rate causing more packet loss, more delay and overall quality degradation. The Datagram Congestion Control Protocol (DCCP) is a congestion control protocol that works on the transport layer and is suitable for use by multimedia applications. DCCP supports many congestion control mechanisms that the application can choose among them according to the type of data being transmitted. In this paper, we propose an algorithm to enhance the performance of DCCP-TCP-like mechanism by adapting slow start threshold (ssthresh) and congestion window (cwnd) with respect to the reset function. The proposed algorithm is analyzed with respect to some important metrics like: packet loss, time delay and consumed energy using the NS-2 simulator. The simulation results indicate that the proposed algorithm can achieve better results than the native mechanisms. We found, during our experiments, that the initial values of ssthresh, cwnd and Retransmission Time Out (RTO) during the reset function have significant effect on the packet delivery ratio (or packet loss). So, determining these values is vital for the stability of the network.