The Comprehensive Review of Congestion Control Techniques in Wireless Sensor Networks
Wireless Sensor Network (WSN) is the event-based system, which consists of independent sensor nodes connected over a distributed network to monitor environmental conditions and it is the immense area of research in the field of networking. The sensor nodes are activated when any event identified and transmit the information to other sensor nodes. In this scenario, when the load becomes heavy, traffic is increased and this may prompt the congestion, and thus few important packets may be dropped in the network, throughput may be reduced, and subsequently, the degraded channel quality reduces the performance of the network. Congestion may also occur by the collision of the packets, overflow of the node buffer, rate of transmission, the techniques such as many-to-one data transmission and dynamic time-variant data transmission, etc. Congestion control in WSNs is the high noteworthy and played a major role in accomplishing high QoS of the system. In addition to this, the packet delivery ratio, end-to-end delay and consumption of energy by the sensors are also affected. Hence, the congestion control mechanism is required to monitor and manage the levels of traffic at an adequate rate. In this paper, numerous congestion control mechanisms proposed by different authors in recent years have been analyzed. We also mentioned different performance metrics that are utilized for estimating the level of congestion.