WSNs (Wireless Sensor Networks in English) are spontaneous networks consist of nodes deployed in large numbers to collect and transmit data to one or more collection points, and this independently.
The sensor nodes usually have the network components of low computing power, memory and energy, access to the radio medium is the most expensive. And reduce this consumption (by reducing the number of packets flowing through the network) and prolong the lifetime of the network is an ongoing challenge for this type of network.

The main task of a sensor node in a network of wireless sensors is the detection process and transmit data. It can participate in a WSN as Sensing node or as a sink node like it is presented below.