A second method of transfer involved special cables that interconnect ports on
two machines. Early PCs used a null modemcable that allowed swapping files
between serial ports; a more current method uses a cable between USB ports.Less common solutions — and those being rapidly supplanted by quick and
inexpensive wireless networks — include use of a home or office’s electrical
power lines or telephone cables. Both of these wired systems are relatively
slow, subject to interference, and may not work at all if your electrical wiring
or telephone system is not continuous from point to point; data may be lost if
there are electrical subpanels or telephone splitters or amplifiers.And in any case, for the purposes of this book I am looking for ways to easily
move your laptop and its data and applications from place to place. The best
solutions here are wireless communication or wired Ethernet.Harald Bluetooth is in the room .......................................................
There’s one more wireless technology that holds a lot of promise for certain
types of devices, although it has not yet grabbed hold of much of the laptop
market: It’s called Bluetooth.Bluetooth is a standard that allows for very quick and easy interconnection
between all sorts of equipment on an ad hoc basis. For example, you could
walk into a room with a Bluetooth-enabled cell phone or personal digital
accessory (PDA,like a Palm Pilot) and immediately be able to exchange data
with any like-minded device. Bluetooth can also be used to allow for cordless
mice, connections to printers and other equipment, and even wireless LANs.Bluetooth operates at a frequency of 2.45 GHz, which is right in the middle of
the WiFi 802.11b and 802.11g range. It does, though, include some sophisti-
cated facilities to avoid interference from other devices.Chapter 14: Feeling Up In the Air 221
Not down in the mouth
Why Bluetooth? I guess I can’t go any further in
this section without explaining how a modern
communications standard ended up with such
a colorful and odd name. The answer lies in the
fact that one center of high technology —
specifically the cell phone industry — is in
Scandinavia with companies including Nokia
(which sounds Japanese but is actually Finnish)
and Ericsson (which is a Swedish company
which also has a 50-50 joint venture with the
Japanese firm Sony).One of the heroes of Scandinavia was this guy
Harald Bluetooth, who was king of Denmark in
the 10th century; during his reign he united
Denmark and part of Norway. As a uniter, not a
divider, his name was deemed appropriate for a
communications standard.