Congestion Control Performance Analysis of CoAP Multicast Group Communication in 6LoWPAN Network

CoAP is a lightweight and efficient application layer protocol designed for resource-constrained devices and networks. It is proposed by the IETF as a replacement for HTTP protocol in such environments commonly found in the Internet of Things (IoT) and Wireless Sensor Networks (WSN). CoAP can also be extended with optional functionality like group communication. Group communication allows communication with multiple resources at once, instead of dealing with resources one by one. CoAP uses IP multicast to send a single request to all members of a group at once. Congestion control plays an important role in managing group communication traffic, so CoAP specifies a CC mechanism when using multicast requests. This paper presents a FiT IoT Lab testbed for performance evaluation of existing CC mechanisms for CoAP group communication traffic in 6LoWPAN (a network protocol engineered to efficiently transmit IPv6 data across low-power, low-rate wireless networks). Metrics like packet delivery ratio and energy consumption are assessed under different test conditions.