The Love-Hate Relationship between IEEE 802.15.4 and RPL

Low-power and lossy networks (LLNs) are at the core of many Internet of Things solutions. Significant standardization effort has been put in creating a protocol stack suited for LLNs. Among these standards, IEEE 802.15.4-2011 and RPL allow LLN devices to form a multi-hop mesh network. Today, RPL creates a routing topology without a priori knowledge about the topology created at the MAC layer. This negatively impacts the number of redundant paths, their quality, and the overall performance of the routing protocol. In this article, we highlight the need for an intermediate layer between the MAC and network layers to solve these problems. We describe the protocols to be used in future Internet of Things, emphasize their weaknesses when deployed together, and propose areas of improvement.