A sensor node [source] is a set of four basic components which are:
- The capture unit: The sensor is generally composed of two subunits: the receptor and the transducer. The sensor is responsible for providing analog signals, based on the observed phenomenon, the A / D converter.
- The processing unit: it consists of a processor (microcontroller) and a storage unit of small size. This unit is responsible for implementing communications protocols that allow the node to collaborate with other network nodes.
- The transceiver unit: it connects the node to the entire network. With this unit, the node can send and receive messages from other nodes.
- The unit of energy: it is the energy source of the sensor node. It can be associated or powered by a power generation unit as solar cells.

One of the most operating systems [source] known in the field of wireless sensor networks is "TinyOS".
It is free and is used by a large community of scientists in simulations for the development and testing of algorithms and network protocols.

TinyOS [source] is an operating system designed to open-source networks of wireless sensors. He meets an architecture based on a combination of components, reducing the code size required for its implementation. This is part of the constraints of memory observed by sensor networks.
Based on an operating event, TinyOS offers the user an exact consumption of the sensor and can better adapt to the random nature of the wireless communication between physical interfaces.