Sustainable Smart World

The smart world is an era in which things (e.g., cars, buses, computers, and mobile phones) can serve people in an effective and collaborative manner. Internet of Things (IoT) connects many devices with each other. IoT devises sense, gather, process, and transmit information from their surroundings. This transmission and exchange of a large amount of data between billions of devices cause massive consumption of energy. The central aim of Green IoT is reducing power consumption of IoT devices to create a safe and sustainable environment for IoT. In this paper, we presented an overview about IoT and the Green IoT, then classified the techniques of the Green IoT into three taxonomies that are Software Based Green IoT techniques, Hardware-Based Green IoT techniques and Policy Based Green IoT techniques. Finally, we compared many Green models, systems, and algorithms to improve and reduce the energy consumption of IoT devices.