PAN for Device Coordination
The PAN, or Personal Area Network, is a low-power, short-range network. Examples of PAN are infrared, Bluetooth, and security networks. The low-power transmitter or Access Point (AP) is wired back to the Internet. However, a PAN can omit an AP and connect devices directly to one another, sending voice and data. It might seem absurd to design a network with a short range. But consider this as the ultimate microcellular division of space, whose room-sized range keeps it from having "conversations" with devices in the next room. The simplest PAN replaces computer, printer, and keyboard cables. It allows nearby machines to communicate data and coordinate services over their wireless network and synchronize data. A PAN web phone works as an antenna to a nearby laptop, transparently passing on email. A set of complying machines go through a discovery protocol, define their own applications, and are often called a federation of devices. Discovery involves exchanging device identities and service capabilities between devices. It also means waking up any relevant information that may be available. A simple example of a device federation is a handheld with a wireless scanner and wireless printer to administer inventory. PAN devices include sensors, scanners, monitors, magnetic card readers, wireless cameras, radio pens, and wireless GPS antennas, which all conspire to increase the operating purposes of wireless devices.
Infrared data (IrDA) is a popular way for handhelds to exchange data or to wirelessly print using strictly a point-to-point, 4-meter line-of-sight connection. Bluetooth is a low-power personal wireless voice and data network that has a range of 10 meters. A Bluetooth PAN, called a piconet, can connect eight devices. It features automatic synchronization and can pass data or voice stream. Any Bluetooth connection can support both data (asynchronous) and voice (synchronous) communications with a total bandwidth of 723 Kbps, including a 57.6 Kbps back channel. Bluetooth devices fit within profiles established by the Bluetooth SIG. Bluetooth profiles provide general characteristics for families of Bluetooth devices.
Future directions for PAN include the creation of "body antennas," work being done between IBM and MIT. On a more serious level, IEEE 802.15 is a new version of the Bluetooth specification. It specifies a version of Bluetooth that will allow 802.11 and 802.15 networks to work together. It also runs at 20 Mbps, exceeding Bluetooth. 802.15 was driven in part by Eastman Kodak Co., which required a wireless format to support downloading photos from a digital camera.