Shabnam Jalili Marandi - Department of Computer Engineering, Faculty of Computer and Electronic Engineering, Science and Research Branch Islamic Azad University, Tehran, Iran
Somaye Jafarali Jassbi - Department of Computer Engineering, Faculty of Computer and Electronic Engineering, Science and Research Branch Islamic Azad University, Tehran, Iran

In recent years, technological advances have caused thousands of devices communicate with each other through the Internet which is called the Internet of Things (IoT). These devices have limited energy, their communications are unstable and dynamic, and the networks formed by these devices are known as LLNs (Low-Power and Lossy Networks). Routing has a very important role in these networks and due to the problems of the limited energy and dynamism in these networks, there are some problems in relation to energy consumption, packet transmission rate, congestion control, estimation of the accurate function of the link, etc. One of the best routing protocols provided for these networks is the RPL routing protocol which is a standard routing protocol based on IPv6 and a lot of research has been done to improve the above-mentioned problems. The present paper aims to collect the methods proposed for improving the RPL protocol in LLNs.

LLN, IPv6, RPL, IoT, link quality, energy consumption, congestion control.