Before Using The Wireless Lan - Fujitsu Lifebook C2230 User Manual

L i f e B o o k C S e r i e s N o t e b o o k - S e c t i o n F i v e

Before Using the Wireless LAN

The Integrated Wireless LAN is an optional device avail-
able for Fujitsu mobile computers. This manual
describes the basic operating procedures for the Wireless
LAN (referred to as the "device" in this manual) and
how to set up a wireless LAN network. Before using this
device, read this manual carefully to ensure correct oper-
ation of the device. Keep this manual in a safe place for
reference while using the device.
Wireless LANs Covered by this Document
This document is applicable to systems containing an
Atheros Wireless LAN.
Characteristics of the Device
This device consists of a wireless LAN card that is
attached inside the computer via a mini-PCI slot.
The main characteristics are as follows:
It operates in the 2.4 GHz Industrial, Scientific, and
■
Medical (ISM) RF band.
It does not require the procurement of an FCC license
■
to operate.
It uses Direct Sequence Spread Spectrum (DS-SS), an
■
RF modulation scheme that is resistant to noise.
This device complies with Wi-Fi, and is able to com-
■
municate at the maximum transfer rate of 11 Mbps.
The maximum communication range is approxi-
■
mately 80 feet (25 meters) inside a building. The
range may be shorter depending upon the installation
factors, such as walls and columns.
Unauthorized access can be prevented with the use of
■
an SSID and an encryption key (also known as a WEP
key).
Figure 5-1. Ad Hoc Mode Network
52
Wireless LAN Modes Using this Device
Ad Hoc Mode (See Figure 1)
"Ad Hoc Mode" refers to a type of wireless network that
involves connecting multiple computers without the use
of an Access Point. Network connectivity between
computers can be established using only wireless LAN
cards in a peer-to-peer fashion.
Ad Hoc networks are an easy and inexpensive method
for establishing network connectivity between multiple
computers.
In the Ad Hoc mode, you can use the function
supported by Microsoft Network, such as File and Print
Sharing to exchange files and share a printer or other
peripheral devices.
To use the Ad Hoc Mode, you must set the same SSID
and the same encryption key for all the computers that
are connected. All connected computers can communi-
cate with each other within the communication range.
Access Point (Infrastructure) Mode (See Figure 2)
If a number of computers are connected simultaneously
in the Ad Hoc mode, the transfer rate may be reduced,
communications may become unstable, or the network
connection could fail. This is because all wireless LAN
cards are using the same radio frequency in the network.
To improve this situation, you can use a wireless LAN
access point, which is sold separately. The wireless LAN
network is in the "Access Point mode" when it uses an
access point, and such a connection is called the "Access
Point Network" or "Infrastructure Network".
By using an access point, you can set and use a different
communication channel for each network group. Each
channel is given a different radio frequency, and it