While most individual nodes in a WSAN are expected to have limited range ( Bluetooth, Zigbee, 6LoWPAN, etc.), particular nodes may be capable of more expansive communications ( Wi-Fi, Cellular networks, etc.) and any individual WSAN can span a wide geographical range. Nodes typically connect in a star or mesh topology. Wireless Sensor Networks (WSN / WSAN) are, generically, networks of low-power, low-cost devices that interconnect wirelessly to collect, exchange, and sometimes act-on data collected from their physical environments - "sensor networks".
Some of these technologies include standards such as ANT UWB, Bluetooth, Zigbee, and Wireless USB. Some examples include wireless headsets for mobile phones or wireless heart rate sensors communicating with a wrist watch. Personal area network (PAN) systems are intended for short range communication between devices typically controlled by a single person. Standards can be grouped as follows in increasing range order: Wireless technologies can be evaluated by a variety of different metrics of which some are described in this entry. A wide variety of different wireless data technologies exist, some in direct competition with one another, others designed for specific applications.