Infrared Data Association (Ir DA) and Bluetooth are the main WPAN wireless technologies; they exist in the physical layer (see Table 9-1).

The devices that take advantage of a WPAN include PDAs, printers, cameras, cell phones, and access points, to name a few.

These devices use wireless technologies to communicate with each other.

The physical layer contains different physical encoding mechanisms for wireless communications.

Windows XP supports the IEEE 802.11b standard natively; this standard uses Direct Sequence Spreading Spectrum (DSSS) to transmit the data in the bandwidth of 2.4 GHz—the Since this bandwidth is free for public use, other devices such as cordless phone can cause problems and interference.

Windows XP's native support for 802.11x simplifies the implementation process for hardware and software vendors.

The basic theory behind wireless technology is that signals can be carried by electromagnetic waves that are then transmitted to a signal receiver.

But to make two wireless devices understand each other, we need protocols for communication.

The other method uses a combination of 802.1x authentication with a back-end Internet Authentication Server and dynamic WEP keys for encryption.

Both methods use strong authentication, which can be based on client certificates. Note: Refer to the "Blueprints" section of this book for network maps of the two recommended wireless network architectures.

Bluetooth, 802.11x, CDMA, GSM, and 3G are different standards that define different methods to physically encode the data for transmission across the airwaves.

In this chapter, we will focus on networks built upon the 802.11x and Bluetooth standards.

Before your enterprise adopts the latest wireless network technologies, you will need to Wireless Infrared Data Association (Ir DA) devices have been supported across many Windows operating systems, including Windows 9x/NT/2000.