Congestion Control Protocols in Wireless Sensor Networks: a comprehensive Survey

In wireless sensor networks (WSNs), when the traffic load on the node exceeds compromised capacity of network channel, congestion occurs. Congestion control is considered a noteworthy challenge in wireless sensor networks, thus it is extremely important to detect, avoid and tackle the congestion while considering the constrained resources of the network. If congestion is not properly handled, it can lead to severe loss of QOS parameters like it may reduce network's throughput, can increase energy consumption as well as end to end delay and can reduce packet delivery ratio at the destination node. In this paper, a detailed analysis of various congestion control protocols are conducted and protocols are divided into four categories i.e. Fairness-Aware congestion control protocol, Power-Aware congestion control protocol and Nature-Inspired congestion control protocol. The congestion control protocols are analyzed in terms of throughput, energy consumption, packet delivery ratio, end to end delay, network lifetime, fairness, weighted average queue length, buffer occupancy etc. Various techniques of congestion detection, congestion notification along with disadvantages of congestion control protocols are discussed in the paper.