Wireless Home Networking - Index of
Wireless Home Networking - Index of
Wireless Home Networking - Index of
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Chapter 3: Bluetooth and Other <strong>Wireless</strong> Networks<br />
Ultracool ultra wideband (UWB) is coming<br />
With all the innovation happening in the Wi-Fi<br />
and Bluetooth areas, more neat stuff is on its<br />
way. Ultra wideband (UWB) is a revolutionary<br />
wireless technology for transmitting digital data<br />
over a wide spectrum <strong>of</strong> frequency bands with<br />
very low power. It can transmit data at very high<br />
rates (for wireless LAN applications in the<br />
home). Within the power limit allowed under<br />
current FCC regulations, ultra wideband also<br />
has the ability to carry signals through doors<br />
and other obstacles that tend to reflect signals<br />
at more limited bandwidths and higher power.<br />
At higher power levels, UWB signals can travel<br />
to significantly greater ranges.<br />
Ultra wideband radio broadcasts digital pulses<br />
(rather than traditional sine waves) that simultaneously<br />
transmit a signal across a very wide<br />
spectrum. The transmitter and receiver are<br />
coordinated to send and receive pulses with an<br />
accuracy <strong>of</strong> trillionths <strong>of</strong> a second! Not only<br />
does UWB enable high data rates, but it also<br />
does so without suffering the effects <strong>of</strong> multipath<br />
interference. (Multipath is the propagation<br />
phenomenon that results in signals reaching the<br />
receiving antenna by two or more paths, usually<br />
because <strong>of</strong> reflections <strong>of</strong> the transmitted signal<br />
<strong>of</strong>f walls or mirrors or the like.) Because UWB<br />
has the ability to time-gate (that is, prescribe the<br />
precise time when it’s supposed to receive the<br />
data), the receiver allows it to ignore signals<br />
arriving outside a prescribed time interval, such<br />
as signals caused by multipath reflections.<br />
UWB is still in the early stages, but it’s coming<br />
on strong. UWB is simpler, cheaper, less powerhungry,<br />
and 100 times faster than Bluetooth.<br />
What more could you want? UWB communication<br />
devices could be used to wirelessly distribute<br />
services such as phone, cable, and<br />
computer networking throughout a building or<br />
home.<br />
Many companies and groups <strong>of</strong> companies<br />
have been promoting UWB for a variety <strong>of</strong> uses.<br />
One <strong>of</strong> them, the WiMedia Alliance, made<br />
(another!) alliance with the Bluetooth SIG to<br />
develop a new 3.0 version <strong>of</strong> Bluetooth that will<br />
eventually allow speeds <strong>of</strong> up to 480 Mbps for<br />
Bluetooth devices.<br />
You may be thinking, well won’t that make Wi-Fi<br />
obsolete? Well it will be as fast as or faster than<br />
Wi-Fi, but it will still be a relatively short-range<br />
technology — this high-speed version <strong>of</strong> Bluetooth<br />
won’t cover your entire home like Wi-Fi will,<br />
so it will still be best suited for cable replacement<br />
rather than whole-home networking.<br />
wireless solutions need a hand from wireline (that is, wired) solutions to give<br />
you a solid, reliable connection into your home network.<br />
A common application <strong>of</strong> wireline and wireless networking is a remote access<br />
point that you want to link back into your home network. Suppose that your<br />
cable modem is in your <strong>of</strong>fice in the basement, and that’s where you have<br />
your main wireless router or access point. Now suppose that you want wireless<br />
access to your PC for your TV, stereo, and laptop surfing in the master<br />
bedroom on the third floor. Chances are that your AP’s signal isn’t strong<br />
enough for that application up there. How do you link one AP to the other?<br />
You could install a wired Ethernet solution, which would entail running new<br />
CAT-5e/6 cables through your walls up to your bedroom. It’s pretty messy<br />
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