Wireless Home Networking - Index of

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