Efficient multicast forwarding in low power and lossy networks under RPL non-storing mode

Abstract

The Internet of Things (IoT) continues to find novel applications across various domains. These applications require the support of efficient communication protocols in the Low Power and Lossy Networks (LLNs). The development of efficient multicast protocols is one such area that requires critical research attention. Efficient multicast protocols are especially important in the non-storing mode of IPv6 Routing Protocol for LLNs (RPL), considering its applicability in real-world IoT applications. However, the development of non-storing RPL multicast protocols needs to handle the intricacies associated with source routing. Addressing these issues, this paper presents a novel multicast protocol named Multicast Forwarding in LLNs under Non-storing mode (MFLN). MFLN uses Bloom Filters to minimize the overhead that comes with source routing. While retaining the best features of multicast protocols operating in the storing mode of RPL such as bidirectional traffic and cross-layer optimization with ContikiMAC, MFLN also includes a novel metric named Mode Selection Metric (MSM) to decide the suitable link-layer forwarding method. MSM makes this decision based on the ability of a node, in terms of its residual energy, to perform multiple link-layer unicasts. Thus, MFLN saves the node battery from running out and at the same time reduces the duplicate packets created due to link-layer broadcasts. The simulations conducted using Contiki-COOJA indicate considerable improvements in terms of packet delivery ratio, energy consumption per delivered packet, packet transmissions, end-to-end delay, and normalized routing overhead for the proposed protocol.