Routing protocol of low-power and lossy network: Survey and open issues

The physical and logical representation of constrained embedded devices such as sensors and actuators plays a significant role in the Internet revolution to next era which is the Internet of Things (IoT). A Wireless Sensor Network (WSN) comprises of several tiny devices (called nodes) with restricted resources and has a capability of sensing and monitoring a certain environment to collect data and sending it to hop by hop to the root node (Sink) via a routing protocol. The routing strategy in WSNs that is called Low power and Lossy Networks (LLNs) determines the lifetime and quality of the network. The nodes in LLNs characteristics (such as low cost, limited storage, computation, and power) could bring an open challenge that is to find out an optimal routing protocol in wireless sensor networks. The IPv6 based RPL routing protocol for LLNs networks are developed based on a selected Objective Functions (OFs) and then different objective functions are used to evaluate the RPL performance to meet various predefined requirements of home-building automation, industrial control, and urban environment. Based on this, the authors attempt to introduce systematic perspectives in terms of RPL and the main metrics that are used in the LLNs. As a result, it is expected to illustrate the conceptual comparison among the metrics in OF's implementation in RPL.