An Organized Study of Congestion Control Approaches in Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are a setup of diminutive, low-cost, self-organizing sensor nodes that can directly sense, process, and forward information from the surroundings to the central location wirelessly. Various challenges in the use of WSNs are energy-aware clustering, node deployment, localization, dynamic topology, congestion control, power management, and data aggregation. Congestion takes place when the packet load arriving at the receiving nodes surpasses the existing sensor network capability. The major aspects that lead to congestion are excess node queue, simultaneous data transmission from multiple source nodes to sink, channel interference, packet clash, and variable data transfer rates. Since the packet distribution rate, transmission delay, throughput, and energy consumption are momentously affected by congestion, it is required to be controlled. This chapter exemplifies a broad assessment of the foremost congestion control techniques applied in WSNs. Further, it classifies the existing approaches into four kinds, specifically, traffic rate regulation protocols, resource allocation based protocols, queue management-based protocols, and priority-aware protocols. The important techniques are compared in terms of congestion detection, notification, and alleviation. This chapter focuses on recent works and presents a discussion on their advantages as well as drawbacks.