A Guide to Sensor Network Terms

RFID tags and wireless sensors share several traits. Both communicate via radio waves, contain a serial number and require the same basic IT infrastructure to aggregate, analyze and distribute data to the people who can act on it. RFID is, in fact, the foundation on which sensor networks are built (once you identify an object, only then does it become possible to know its condition). Here are some common terms related to sensor technology
Published: October 1, 2004

Active RFID sensor: An active RFID tag integrated with a sensor that measures temperature, the presence of radiation or other environmental conditions. Active RFID sensors communicate only with a reader, not with one another.

Mesh network: Sometimes called an ad hoc network, a mesh network is a network of wireless microcomputers that communicate with other wireless devices in their vicinity, rather than communicating with a single node in a point-to-point network.

Mote: A small, self-powered device with a microprocessor and radio transceiver. Motes run their own operating system, such as TinyOS, which was developed at the University of California at Berkeley. They can be integrated with sensors to create smart dust (see below). Motes communicate with one another and pass information to a node near a reader that is connected to a wireless or wired corporate network, so data from the motes can be collected, analyzed and shared using enterprise IT systems.

Passive RFID sensor: A passive RFID tag integrated with a sensor. Passive RFID tags do not have a transmitter or their own power source. They simply reflect back radio waves from a reader. A passive sensor is less expensive than an active RFID sensor, and it has no battery to replace.

Smart dust: A generic term used to describe motes that are integrated with sensors that may track movement, temperature or other environmental conditions.

Telemetry: The science and technology of automatic measurement and transmission of data by wire, radio or other means from remote sources (such as spaceships or trucks on the road) to receiving stations for recording and analysis.