Wireless sensor networks growing very popular technology; however it is very important to understand the architecture for this kind of network before deploying it in any application. A wireless sensor network consists of automatic sensors which will monitor either physical or environmental conditions. These include temperature, sound, vibration, pressure, humidity, motion or pollutants. They then send data through the network back to main location. It is made of nodes and these people could range in number from hundreds to thousands within the network. These nodes contain several parts including a radio transceiver with an internal antenna or link to an external antenna, a microcontroller, be sure you circuit for interfacing with the sensors and an power source which may be a battery or an embedded form of one's harvesting. The most common structure of WSN's follows the OSI model. There are 5 layers required in the network including an application layer, transport layer, network layer, data link layer and an actual layer. It is also made up of cross planes/layers like power management plane, mobility management plane and task management plane. These tend to be to manage the network and develop the sensors work together in the correct order to increase efficiency. Applications include: Area Monitoring The WSN is installed over a part where some phenomenon is to be monitored. An example is the associated with sensors to detect enemy intrusion; a civilian example is the geo-fencing of gas or oil pipelines. When the sensors detect the event being monitored (heat, pressure), the event is reported to at least of the base stations. Environmental Sensing Environmental Sensor Networks has evolved to coat many applications of WSNs to earth science research. Consists of sensing volcanoes, oceans, glaciers, forests several. Air pollution monitoring WSN's been recently deployed a number of cities including Stockholm, London and Brisbane, to monitor the power dangerous smells. These can take regarding the ad-hoc wireless links rather than wired installations, which also make them more mobile for testing in different areas. Greenhouse monitoring They is utilized to control the temperature and humidity levels inside commercial garden greenhouses. When the temperature and humidity drops below certain levels, the greenhouse manager must be notified via e-mail or cell phone text message, or host systems can trigger misting systems, open vents, turn on fans, or control all sorts of system responses. Machine health monitoring Wireless sensor networks already been developed for machinery condition-based maintenance (CBM) as they significant enhanced and enable new features. In wired systems, installing the device of enough sensors is usually limited coming from the cost of wiring. Previously inaccessible locations, rotating machinery, hazardous or restricted areas, and mobile assets are now able to be reached with wireless sensors. Data logging WSN's can be employed for the gathering of data for monitoring environmental information, this can be as simple as the monitoring of your temperature in a fridge towards the level of water in overflow tanks in nuclear power plants. The information can then be acquainted with show how systems have been working. Water/Waste monitoring There a lot of opportunities for making use of wireless sensor networks on the inside water/wastewater groups. Facilities not wired for power or data transmission can be monitored using industrial wireless I/O devices and sensors powered using solar panels or battery packs can even be used in pollution limit. These are exactly a few of the uses for WSN's, the list goes on. Wireless communicationscompared with wired solutions means you you're able to reduce implementation costs, become more energy efficient and reach sensors in remote points.