22.1.3.3 Wireless Communication
As well as connecting to a home or ofce network with a cable, a laptop can also use
wireless connection to access other computers, peripherals, cellular phones or PDAs.
Linux supports three types of wireless communication:
WLAN
With the largest range of these wireless technologies, WLAN is the only one suitable
for the operation of large and sometimes even spatially separate networks. Single
machines can connect with each other to form an independent wireless network or
access the Internet. Devices called access points act as base stations for WLAN-
enabled devices and act as intermediaries for access to the Internet. A mobile user
can switch among access points depending on location and which access point is
offering the best connection. Like in cellular telephony, a large network is available
to WLAN users without binding them to a specic location for accessing it. Find
details about WLAN in Chapter 24, Wireless LAN (page 431).
Bluetooth
Bluetooth has the broadest application spectrum of all wireless technologies. It can
be used for communication between computers (laptops) and PDAs or cellular
phones, as can IrDA. It can also be used to connect various computers within range.
Bluetooth is also used to connect wireless system components, like a keyboard or
a mouse. The range of this technology is, however, not sufcient to connect remote
systems to a network. WLAN is the technology of choice for communicating
through physical obstacles like walls.
IrDA
IrDA is the wireless technology with the shortest range. Both communication parties
must be within viewing distance of each other. Obstacles like walls cannot be
overcome. One possible application of IrDA is the transmission of a le from a
laptop to a cellular phone. The short path from the laptop to the cellular phone is
then covered using IrDA. The long range transport of the le to the recipient of
the le is handled by the mobile network. Another application of IrDA is the
wireless transmission of printing jobs in the ofce.
22.1.4 Data Security
Ideally, you protect data on your laptop against unauthorized access in multiple ways.
Possible security measures can be taken in the following areas:
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