Customers and things are connected via the Internet of Things (IoT) at any time and place. IoT provides a significant contribution to modern communication. The IoT creates the modern world, where things represent smart devices, mobile phones, wireless nodes, and many other objects.

Contiki is an operating system focusing on implementing low-power IoT devices. Cooja is the Contiki network simulator, and it is the tool to simulate large and small networks of Contiki motes.

The software package in the Contiki-Cooja simulator contains a UNIX-style shell for OS interface and debugging. A network can be implemented with a package of different layers and corresponding protocols. Various OSI layers are given along with their protocols.