Chapter 2: Planning Your Wireless
Network
A wireless local area network (WLAN) is exactly like a regular local area network
(LAN), except that each computer in the WLAN uses a wireless device to
connect to the network. Computers in a WLAN share the same frequency
channel and SSID, which is an identification name for wireless devices.
Unlike wired networks, wireless networks have two different modes in which
they may be set up:
infrastructure
and
ad-hoc
. An infrastructure configuration
is a WLAN and wired LAN communicating to each other through an
access point. An ad-hoc configuration is wireless-equipped computers
communicating
directly with each other. Choosing between these two modes
depends on whether or not the wireless network needs to share data or peripherals
with a wired network or not.
If the computers on the
wireless network need to
be accessed by a wired
network or need to share a
peripheral, such as a
printer,
with the wired network
computers, the wireless
network should be set up
in
infrastructure
mode.
(See Figure 2-1.) The
basis of infrastructure
mode centers around an
access point
, which serves
as the main point of communications in a wireless network. Access points
transmit data to PCs equipped with wireless network cards, which can
roam
within a certain radial range of the access point. Multiple access points can be
arranged to work in succession to extend the roaming range, and can be set up
to communicate with your Ethernet (wired) hardware as well.
Network Topology
Ad-Hoc versus Infrastructure Mode
If the wireless network is relatively small and needs to share resources only
with the other computers on the wireless network, then the
ad-hoc
mode can
be used. (See Figure 2-2.) Ad-hoc mode allows computers equipped with wireless
transmitters and receivers to communicate directly with each other, eliminating
the need for an access point. The drawback of this mode is that, in Ad-
Hoc mode, wireless-equipped computers are not able to communicate with
computers on a wired network. And, of course, communication between the
wireless-equipped computers is limited by the distance and interference directly
between them.
