Page 17 - DCAP311_DCAP607_WIRELESS_NETWORKS

Unit 1: Introduction to Wireless Networks

These are networks that provide wireless connectivity over distances of up to 10m or so. At first Notes
this seems ridiculously small, but this range allows a computer to be connected wirelessly to a
nearby printer, or a cell phone’s hands-free headset to be connected wirelessly to the cell phone.
The most talked about (and most hyped) technology is called Bluetooth.
Personal Area Networks are a bit different than WANs and WLANs in one important respect.
In the WAN and WLAN cases, networks are set up first, which devices then use. In the Personal
Area Network case, there is no independent pre-existing network. The participating devices
establish an ad-hoc network when they are within range, and the network is dissolved when the
devices pass out of range. If you ever use Infrared (IR) to exchange data between laptops, you
will be doing something similar. This idea of wireless devices discovering each other is a very
important one, and appears in many guises in the evolving wireless world.

PAN technologies add value to other wireless technologies, although they wouldn’t be the
primary driver for a wireless business solution. For example, a wireless LAN in a hospital may
allow a doctor to see a patient’s chart on a handheld device. If the doctor’s handheld was also
Bluetooth enabled, he could walk to within range of the nearest Bluetooth enabled printer and
print the chart.

WPANs are short-range networks that use Bluetooth technology. They are commonly used to
interconnect compatible devices near a central location, such as a desk. A WPAN has a typical
range of about 30 feet.
Wireless PANs make use of both radio and infrared light technologies, which manufacturers
embed in many different types of devices.

User Devices

Wireless PANs don’t require much battery power to operate, making them ideal for small user
devices, such as audio headsets, cell phones, PDAs, game controls, GPS units, digital cameras,
and laptops. Figure 1.1 illustrates several of these types of devices. For example, a wireless
PAN enables someone to listen to music on headsets wirelessly from their PDA. Or a person
can transfer his phone book from his laptop to a cell phone. As with these cases, wireless PANs
eliminate wires that often frustrate users.
Figure 1.1: Many Different Types of User Devices Operate on Wireless PANs

Source: http://etutorials.org/Networking/wn/Chapter+4.+Wireless+PANs+Networks+for+Small+Places/Wireless+PAN
+Components/
Radio NICs

Radio NICs are available for wireless PANs in PC Card and Compact Flash (CF) form factors.
If you have a laptop, for example, it’s easy to add wireless PAN connectivity by installing a

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