Throughput Evaluation of a Novel Scheme to Mitigate the Congestion over WSNs

In recent years, due to fast development of wireless sensor networks (WSNs), the numbers of nodes are increasing, and their scope of applications is continuously expanding, including environmental monitoring, military and smart home applications. The power supply, memory and computing power of wireless sensor nodes are greatly hampered in WSNs so that the WSNs are classified as a task-oriented framework. This study focused on exploring problems caused by traffic congestion on the WSNs with a large amount of flow, such as packet loss, bandwidth reduction, and waste of energy on the sensor nodes. On the other hand, a cooperative strong node mechanism is presented and named as Cooperative Strong Node Mechanism, in which a threshold is set to determine whether the node traffic is over or not. When the load exceeds, the privilege of corresponding sensor nodes is upgraded so that it can command its child nodes to change the transmission path to distribute the traffic effectively. Furthermore, when the traffic exceeds preset overall network flow, new sensor nodes are added in the network to relieve the traffic. This novel proposed mechanism can not only increase network throughput and effectively prevent the occurrence from congestion problems, but is suitable for a variety of routing protocols.