I. Introduction
Internet of things is the advent of exciting and most dynamic developments in the field of information and communication technology. Over the past two decades we have seen that network topologies are restricted in connecting the end-user devices such as laptops, desktops, smartphones and tablets which are available recently [1], [2]. Now in today’s scenario devices are now connected to networks which include electric meters, medical devices, street lights, smart TVs, traffic controls and Alexa and Google home as digital assistants. Hence by 2020, the number of devices connected to internet has expanded approximately by 25 billion and it may generate US$13 trillion revenue by 2025 [3], [4].