Wireless Sensor Network (WSN)
Wireless sensor network :a network consists of a large number of sensor nodes where that nodes
spread extensively within the area . This sensor nodes are linked to computers and spread in large numbers up to hundreds or thousands of these nodes at a lower cost , small size and need less energy.
According to Moore’s Law number of transistors that each slice of silicon doubles every two years
this development has led to the manufacture of small integrated devices which have the ability to connect wirelessly . these sensors can deal Directly with the surrounding environment that can sense the physical events such as temperature and humidity, lighting, pressure.
these sensors can cooperate with each other to send the sensor data wirelessly to the monitoring station, which can collect data physical analysis and take the necessary measures.
Wireless sensor networks are one of the most modern technologies in the field of computing that
opened the door to a new generation of applications in diverse areas such as environment monitoring ,
Weather monitoring and checking the integrity of buildings, facilities and security such as the incursions into restricted areas a, traffic and fire detection.
Applications of sensor networks :
1 – Military applications
- Nuclear, biological and chemical attack detection
- Monitoring friendly forces, equipment and ammunition
2 – Environmental applications
- Flood detection
- Precision agriculture
- Forest fire detection
3 – Health applications
- Tele-monitoring of human physiological data
- Tracking and monitoring patients and doctors inside a hospital
- Drug administration in hospitals
4 – Home and other commercial applications
- Home automation and Smart environment
- Managing inventory control
- Vehicle tracking and detection
- Detecting and monitoring car thefts
Hardware constraints for sensor nodes :
- Power : Require high lifespan .
- Processor : Collecting data , analysis and processing of observed data then send this secret Data to other nodes .
- Storage : SDRAM +SRAM to save data before analysis and before sending .
- Radio : Send and receive data from or to other nodes .