A Comparative analysis of CoAP based Congestion Control in IoT

The lightweight Constrained Application Protocol (CoAP) has been standardized by IETF for the constrained IoT devices operating in lossy environments. It runs over unreliable UDP protocol for communication, reliability, and congestion management. Congestion in the network grows as the number of transmissions increases, making it more difficult to alleviate congestion with the conventional CoAP approach. CoAP is also not adaptive to various network conditions. To overcome such limitations of CoAP, some enhancements of the basic CC mechanism have been proposed recently. This paper presents a comparative analysis of several congestions control mechanisms and highlights some of their advantages and disadvantages.

I. Introduction

IoT is a vast and open network of smart devices that are able to communicate and share data without human interaction. A large number of devices in an IoT are constantly growing. It leads to network congestion due to the high volume of data exchanged among nodes. Additionally, IoT devices are bound by processing power and memory, which exacerbates network congestion. Congestion degrades QoS, a performance metric that includes delay, throughput, and PDR. Congestion also arises when a network's traffic load approaches its capacity. It is one of the primary impediments that still prevent the well-functioning of several protocols and thus has a direct effect on the efficiency of the communication.