A Review on RPL Objective Function Improvements for IoT Applications

The standard routing technique that was developed for satisfying low power IoT application needs is RPL which is a protocol in compliance with 6LoWPAN specification. RPL was created for addressing the issues and challenges of constrained and lossy network routing. However, RPL does not accomplish efficiency with respect to power and reliability altogether which are definitely needed in IoT applications. RPL runs on routing metrics and objective function which determines the optimal path in routing. This paper focuses on contributing a comprehensive survey on the improved objective functions proposed by several researchers for RPL. In addition, the paper concentrates on highlighting the strengths and shortcomings of the different approaches in designing the objective function. The approaches built on Fuzzy logic are found to be more efficient and the relevant works related to these are compared. Furthermore, we present the insights drawn from the survey and summarize the challenges which can be effectively utilized for future works.