Abstract
Internet of Things (IoT) is described as a set of inter-connected objects that communicate through a network connection. IoT has been used in a variety of applications such as smart cities, education, and healthcare etc. Due to their implicit nature and usage, IoT devices have limited resources such as memory size, battery power, and processing capabilities. Hence, it is vital to consider IoT Operating Systems (IoT-OS) that are responsible for managing and controlling the IoT device's limited resources in a timely and efficient manner. This paper provides a detailed comparison of several existing IoT-OSs in terms of architecture, memory management, power management, scheduling algorithms, programming languages, file system management, and security features. In addition, it investigates various popular IoT-OSs including Contiki, TinyOS, RIOT, Lite OS, FreeRTOS, and Mbed. IoT-OS security model has been proposed to be used by many IoT application areas.