Enhanced Multicast Protocol for Low-Power and Lossy IoT Networks

Communication protocols in the Internet of Things (IoT) should take into account the resource-constrained nature of low-power and lossy networks (LLNs). IP multicast protocols allow a packet to be routed from one source to multiple destinations in a single transmission. Hence, resources such as bandwidth, energy, and time are saved for a multitude of LLN applications, ranging from over-the-air programming and information sharing to device configuration and resource discovery. In this context, several multicast routing protocols have recently been proposed for LLNs, including the multicast protocol for LLNs (MPL). MPL has proven to be very reliable in many scenarios. However, the great resource consumption, especially in terms of energy and bandwidth, remains the main drawback of this protocol. In this article, after a detailed overview, we provide an in-depth analysis of the MPL protocol to highlight its functional weaknesses. Then, we propose several improvements that touch on different areas to address such limitations. Extensive realistic simulations and experiments were performed to study the performance of the proposed improvements to MPL. The results obtained show that our proposals outperform the MPL protocol in terms of resource consumption (memory, bandwidth, and energy) while improving its performance in terms of end-to-end delay and maintaining the same reliability of data packet delivery.