4. Communication protocols

Sensors in a network communicate with each other via radio links. These links are shared by neighboring nodes. To avoid interference, each communication must take place on its own. Access to the medium is then divided into chunks to enable all sensors to communicate. There are a number of standards that provide a communication protocol for the sensor network. Here we distinguish three different ones: Bluetooth, ZigBee and Wi-Fi. The first two belong to the family of personal networks, and have been designed to take into account the environment of small devices with low autonomy. Wi-Fi, on the other hand, is not well suited to sensors, but we have chosen to mention it because a number of experiments have been carried out in sensor networks using Wi-Fi as the communication protocol.