Wireless sensor networks
This article does not contain any cited references
This article provides an introduction of wireless sensor networks. It pays attentions to the application and main characteristics of wireless sensor systems.
A wireless sensor network is a collection of sensor nodes, linked together via some form of wireless communication network. These sensor nodes are autonomous devices using a variety of sensors (e.g., temperature, sound, vibration, pressure, motion, or pollutant) to monitor the environment in which they are deployed. A number of different node manufacturers exist (e.g., MoteIV and Xbow), which build nodes suitable for deployment in outdoor areas, in buildings, as well as underwater.
In addition to a wide array of sensor nodes and sensing technologies, there is also a wide array of wireless technologies. For both in building and outdoor environments, Zigbee is among the more popular wireless technologies. Underwater deployments use acoustic modems for their communication (see e.g. underwater video systems).
The applications for wireless sensor networks are broad. Commercial and industrial applications include monitoring equipment to which it is difficult to attach wired sensors, or in older buildings where it is difficult to retrofit a wired network. Environmental monitoring (e.g., coastal monitoring) applications abound due to the ease of deployment, and the minimal impact on the environment. Sensor networks not only eliminate the need for wires, but also do not typically require large power supplies. Common applications for sensor networks include: environmental monitoring, habitat monitoring, acoustic detection, seismic detection, military surveillance, inventory tracking, medical monitoring, smart space, etc. See e.g. Monitoring biodiversity in dunes, beaches and salt marshes, Instruments and sensors to measure environmental parameters.
Wireless Sensor Networks have a number of unique characteristics: small-scale sensor nodes, limited power supply, energy harvesting, harsh environmental conditions, node failures, mobility of nodes, mobility of detected events, dynamic network topology, heterogeneity of nodes, large scale deployments, and unattended operation.
Operating systems for wireless sensor networks are less complex than general-purpose operating systems because of special requirements for sensor networks and because of their embedded nature. For example, sensor network applications usually do not require user interaction; therefore, support of terminals, GUIs, and standard input devices are not built in. TinyOS is the most well known operating system for sensor networks, though there are others. TinyOS is an event-driven operating system and applications are written as groups of event handlers. When an event occurs, such as a sensor reading or a timer expiring, TinyOS calls the appropriate event handler for execution.
For further information, there are a number of good technical conferences:
Please note that others may also have edited the contents of this article.