Personal Area Networks (PANs)

A personal area network (PAN) is a short-range wireless network that can span from a few feet to a few hundred feet. This covers many different short-range wireless standards.

As weird as it may sound, a recent PAN solution may enable you to exchange data (such as an electronic business card, or other similar information) by simply shaking hands with another person. How is this possible? IBM is currently developing a PAN solution that involves passing a very small amount of electrical current through the human body. The amount of current used is much smaller than that already passing naturally through your body. Using a PAN, it would also be possible to create devices that connect your Dick Tracy wristwatch to other larger computing devices simply by walking past them, transmitting a signal through your shoes. This may sound far- fetched , but development is underway at this time, and standards for PANs are still being developed. For more information about the ongoing development of PANs and the use to which they can be put, check out the Web site www.IEEE.org.

Another sort of PAN is the Bluetooth technology discussed in Chapter 23, "Bluetooth Wireless Technology." Although) not as succinct as the PAN previously described, Bluetooth provides communications between devices over a very short range. However, if Bluetooth continues down the development path that currently appears to be competitive with the IEEE 802.11 standards, then it may not be considered a PAN alternative in the future.

Bluetooth can be used to create a wireless environment for PCs so that you don't have to have all those cables connecting your keyboard, printer, mouse, and other peripheral devices. Bluetooth has undergone a long, rough ride to get to the consumer marketplace . When the third edition of this book was published, you would have been hard-pressed to find any Bluetooth device at a computer or consumer electronics store. Today, the technology is now widely available. Today Bluetooth devices are just as common in your consumer electronics store as Wi-Fi devices.

Yet, because most of this chapter is devoted to security issues, it is worth noting that you should probably limit the use of Bluetooth in large networks. Because so many consumer devices can be used to associate with a computer or another device, and because the security mechanisms used by Bluetooth at this time are not entirely secure, Bluetooth should be usually used only in a nonsecure network, such as a SOHO network where security is not a great issue.

The IEEE approved the 802.15.1 standard for personal area networks (PANs), adopting much of the technology from Bluetooth standards.

The basics of a PAN is a network limited to just 255 devices, and a connection to a wired network is not generally allowed. Only one device is enabled to control the PAN, and it is responsible for controlling traffic between other similar devices. The controlling device allocates time slots for each device that makes a request to transmit data.

The IEEE is also working on other versions of this standard, which involve higher data rates as well as reducing the power requirements for PANs.

In the future you might expect various consumer devices (as well as computers) to interact using PAN technology. For example, it might just be that in the future you can use your watch to instruct the thermostat in your house what temperature you want it to be set at. Or you might have a stove that incorporates both heating and refrigeration capabilities to )defrost and have dinner waiting for you at the time you request!