Wireless Lan Basics - D-Link DSL-G604T User Manual

DSL-G604T Wireless ADSL Router User's Guide

Wireless LAN Basics

Some basic understanding of 802.11b/g wireless technology and terminology is useful when you are setting up
the Router or any wireless access point. If you are not familiar with wireless networks please take a few minutes
to learn the basics.
Radio Transmission
Wireless LAN or WLAN devices use electromagnetic waves within a broad, unlicensed range of the radio
spectrum to transmit and receive radio signals. When a wireless access point is present, it becomes a base station
for the WLAN nodes in its broadcast range. WLAN nodes transmit digital data using FM (frequency
modulation) radio signals. WLAN devices generate a carrier wave and modulate this signal using various
techniques. Digital data is superimposed onto the carrier signal. This radio signal carries data to WLAN devices
within range of the transmitting device. The antennae of WLAN devices listen for and receive the signal. The
signal is demodulated and the transmitted data extracted. The transmission method used by the access point is
called Direct Sequence Spread Spectrum (DSSS) and operates in a range of the radio spectrum between 2.4GHz
and 2.5GHz for transmission. See the technical specifications for more details on wireless operation.
Range
Range should not be a problem in most homes or small offices. If you experience low or no signal strength in
some areas, consider positioning the Router in a location between the WLAN devices that maintains a roughly
equal straight-line distance to all devices that need to access the Router through the wireless interface. Adding
more 802.11g access points to rooms where the signal is weak can improve signal strength. Read the section
about placement of the Router titled Location in the next chapter, Hardware Installation, for more information.
SSID
Wireless networks use an SSID (Service Set Identifier) to allow wireless devices to roam within the range of the
network. Wireless devices that wish to communicate with each other must use the same SSID. Several access
points can be set up using the same SSID so that wireless stations can move from one location to another without
losing connection to the wireless network.
The DSL-G604T operates in Infrastructure mode. It controls network access on the wireless interface in its
broadcast area. It will allow access to the wireless network to devices using the correct SSID after a negotiation
process takes place. By default he DSL-G604T broadcasts its SSID so that any wireless station in range can learn
the SSID and ask permission to associate with it. Many wireless adapters are able to survey or scan the wireless
environment for access points. An access point in Infrastructure mode allows wireless devices to survey that
network and select an access point with which to associate. You may disable SSID broadcasting in the web
manager's wireless menu.
Wireless Security
Various security options are available on the DSL-G604T including open or WEP, WPA, and WPA-PSK.
Authentication may use an open system or a shared key. For details on these methods and how to use them,
please read the wireless LAN configuration information in chapters 3 (Basic Router Configuration) and 4
(Advanced Router Configuration) below.
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