A comprehensive study of RPL and P2P-RPL routing protocols: Implementation, challenges and opportunities

In recent years, Internet of Things (IoT), which aims to achieve ubiquitous communication among a large number of resource constraint embedded devices, has emerged as a new paradigm in the field of wireless communications. Enabling the IoT essentially requires thousands of low-power and low cost embedded devices to be efficiently and seamlessly interconnected. Consequently, routing protocols play a crucial role in providing the interoperability for IoT components. In order to turn IoT into reality, IETF has standardized the IPv6 Routing Protocols for Low-power and Lossy Networks (RPL). As the pervasiveness of RPL increases, a comprehensive survey of RPL is crucial to pave the way for researchers to understand and contribute in the relevant research area of RPL. Therefore, in this paper, we present a comprehensive study of RPL protocol as well as its latest and standardized addition, i.e., point-to-point RPL (P2P-RPL). Specifically, this paper focuses on performance evaluations, research challenges and envisioned opportunities of RPL. In addition, we also introduce a NS-3 framework design of RPL and P2P-RPL protocols. Furthermore, extensive simulation studies are conducted across various scenarios to demonstrate the flexibility and effectiveness of RPL and P2P-RPL protocols. Moreover, research gaps and challenges facing in RPL and P2P-RPL protocols are also addressed. Finally, we summarize the paper by providing valuable insights of enabling technologies and suggestions for future research.