D-Link Air DWL-120 User manual

DWL-120
Wireless USB Adapter
User's Manual

Table of Contents for the DWL-120
Wireless USB Adapter
Introduction i
Contents of Package ii
Wireless Basics 1
Getting Started 3
Configuration Utility 10
Troubleshooting 20
Networking Basics 38
Technical Support 65
Specifications 66
Warranty 70
Registration 75

INTRODUCTION
The D-Link DWL-120 802.11b Wireless USB Adapter is an
ideal way to connect your laptop computer to a wireless network
or as part of a wired LAN (Local Area Network) with a wireless
network segment. After completing the steps outlined in this
manual, you will have the ability to share information and
resources - such as files and printers- and take full advantage of
a “connected” environment for work and play!
This DWL-120 comes with drivers for the most popular operating
systems and can be integrated into a large network. The
User’s Manual is designed to help you connect your
computer to a network when running Windows 98, Windows
ME, or Windows 2000 in either Ad Hoc mode (without an
Access Point) or Infrastructure mode (with an Access Point).
Yet the IEEE802.11b standards compliance means this adapter
gives you the flexibility to connect it to any 802.11b networks.
The IEEE 802.11bEthernet standard allows you to connect
computers and devices at speeds up to 11Mbps, depending on
the distance between wireless adapters.
This manual provides a quick introduction to wireless
technology and its application as it relates to networking.
Take a moment to readthrough this manual and familiarize
yourself with wireless technology. But you should also give
yourself some time to play with your new wireless network.
i

CONTENTS OF PACKAGE
CD
B
ii
A
DWL-120 Wireless USB Adapter Package Contents
ADWL-120 Wireless USB Adapter with cable
BDriver CD
CUser’s Manual
DQuick Install Guide

WIRELESS BASICS
Your new D-Link Air product is based on industry standards to pro-
vide easy to use and compatible high speed wireless connectivity
within your home or business. Strictly adhering to IEEE 802.11b,
the D-Link Air family of products will allow you to access the data
you want, when and where you want it. No longer will you be teth-
ered to a workstation or forced to run new wiring. You will be able
to enjoy the freedom that wireless networking delivers.
Standards Based Technology
Based on IEEE 802.11b, D-Link Air products can perform up to 11
Megabits per second. This means you will be able to transfer
large files quickly or even watch a Movie in MPEG format over
your network without noticeable delays. This technology works by
using multiple frequencies in the 2.4GHz range utilizing Direct
Sequence Spread Spectrum (DSSS) technology. D-Link Air prod-
ucts will automatically sense the best possible connection speed to
ensure the greatest speed and range possible with the technology.
Installation Considerations
Designed to go up to 100 meters indoors and up to 300 meters
outdoors, D-Link Air lets you access your network from anywhere
you want. However, keep in mind, that range is limited by the
number of walls, ceilings, or other objects that the wireless signals
must pass through. Typical ranges vary depending on the types of
materials and background RF noise in your home or business.
The key to maximizing range is to follow these basic principles:
1

WIRELESS BASICS
1. Keep the number of walls and ceilings to a minimum -
Each wall or ceiling can rob your D-Link Air Wireless
product from 1-30M of range. Position your Access
Points, Residential Gateways, and computers so that
the number of walls or ceilings is minimized.
2. Be aware of the direct line between Access Points,
Residential Gateways, and Computers -
A wall that is .5 meters thick, at a 45 degree angle
appears to be almost 1 meter thick. At a 2 degree
angle it looks over 14 meters thick! Try to make sure
that the AP and Adapters are positioned so that the
signal will travel straight through a wall or ceiling for
better reception.
3. Building Materials make a difference -
A solid metal door or aluminum studs may have a neg-
ative effect on range. Again, try to position Access
Points, Residential Gateways, and Computers so that
the signal passes through drywall or open doorways
and not other materials.
4. Make sure that the antenna is positioned for best reception
by using the software signal strength tools
included with your product.
5. Keep your product away (at least 1-2 meters) from electrical devices
that generate RF noise, like microwaves, Monitors,
electric motors, etc.
For the average American 4-bedroom home, range should not be a
problem. If you experience low or no signal strength in areas of
your home that you wish to access, consider positioning the
Access Point in a location directly between the Residential
Gateways and/or Computers that will be connected. Additional
Access Points can be connected to provide better coverage in
rooms where the signal does not appear as strong as desired.
2

GETTING STARTED
To begin, you must select the type of wireless network you will
be building and follow the relevant instructions.
Which statementbelow best describes the type of network you
want to build?
The Home Internet Network with A Residential
Gateway, Firewall, or Router(LAN administrators
with Dynamic IPs should follow these instructions)
"I have 2 or more computers and/or laptops and want to share
files, printers, and Internet access using a Residential
Gateway, Router, or Firewall or I want to connect to an
Ethernet network that uses Dynamic (DHCP) IP addresses"
(requires a Wireless Router or Access Point and Ethernet capable
Gateway, Router, or Firewall or an existing Ethernet network).
When you have installed your wireless network it will look
like this:
3

GETTING STARTED
Please note that this type of installation requires that your
Residential Gateway, Router, Firewall or Network Administrator
can give you a dynamic IP address for each computer. Please
consult the documentation that comes with your Access Point to
determine its necessary configuration.
To complete this installation, please follow these steps:
1.Using the provided Ethernet cable, connect the router to the
Cable/DSLmodem. Also connect the Access Point to the Router.
2. Install the Wireless Adapter - see the Quick Install Guides.
3. Check the wireless connection- see Configuration Utility and
Networking Basics section.
4. Check IP Address for the wireless adapter - see Networking Basics
section.
NOTE: The default settings for the wireless adapter is set to obtain a
Dynamic IP Address.
5. Learn to share printers and files - see Networking Basics section.
4

GETTING STARTED
The Home Internet Network with Multiple IPs (LAN
administrators with Static IPs should follow
these instructions).
"I have 2 or more computers and/or laptops and want to share
files, printers, and Internet access using multiple IP addresses
thatI have purchased from my Internet Service Provider or I
want to connect to an Ethernet network that uses Static IP
addresses" (requires Access Point, Ethernet capable
Broadband modem, and multiple IP address Internet Account
or an existing Ethernet network).
When you have installed your wireless network it will look
like this:
5

GETTING STARTED
Please note that this type of installation requires that your ISP
or Network Administrator can give you a static IP address for
each computer. Please consult the documentation that comes
with your Access Point to determine its necessary configuration.
To complete this installation, please follow these steps:
1.Using the provided Ethernet cable, connect the router to the
Cable/DSLmodem. Also connect the Access Point to the Router.
2. Install the wireless Adapter - see the Quick Install Guides.
3. Check the wireless connection- see Configuration Utility and
Networking Basics section.
4. Set Static IP Address for the wireless Adapter - see Networking
Basics section.
NOTE: If you are using a PPPoE client, go to “Networking Basics
section” instead. Verify the settings with your ISP or Network
Administrator if necessary.
5. Learn to share printers and files - see Networking Basics.
6

GETTING STARTED
The Ad Hoc Network
"I have 2 or more computers and/or laptops and just want to
share files and printers."
When you have installed your wireless network it will look
like this:
To complete this installation, please follow these steps:
1. Install the wireless adapter - see the Quick Install Guides.
2. Set Static IP Address for the wireless adapter - see Networking
Basics section.
3. Check the wireless connection- see Configuration Utility and
Networking Basics section.
4. Learn to share printers and file - See Networking Basics.
7

GETTING STARTED
The Ad Hoc Network with Internet Sharing
"I have 2 or more computers and/or laptops and want to share
files, printers, and Internet access using one computer or laptop
as an Internet Server" (requires Internet sharing software).
When you have installed your wireless network it will look
like this:
To share an Internet connection with Internet Sharing software
you will need to purchase Internet Sharing software or use
Windows 98SE's or ME's Internet Connection Sharing (ICS)
utility. Please follow your software documentation to properly
configure the Internet sharing software after you install your
wireless networking adapters. To install your wireless network
adapter follow these steps:
8

GETTING STARTED
If the Internet Sharing Software will be installed on the same computer
into which you are installing this wireless network adapter follow
these steps:
1. Install the wireless adapter - see the Quick Install Guides.
2. Set Static IP Address for the wireless adapter - see Networking
Basics section.
3. Check the wireless connection- see Configuration Utility and
Networking Basics section.
4. Learn to share printers and file - See Networking Basics.
5. Install your Internet Sharing Software.
If the Internet Sharing Software is installed on a
different computer follow these steps:
1. Install the wireless adapter - see the Quick Install Guides.
2. Check IP Address for the wireless adapter - see Networking Basics
section.
NOTE: The default settings for the wireless adapter is set to obtain a
Dynamic IP Address.
3. Check the Wireless connection- see Configuration Utility and
Networking Basics section.
4. Learn to share printers and file - See Networking Basics.
9

CONFIGURATION UTILITY
D-Link Air adapter products use the "Configuration Utility" as the
management software. The utility provides the user an easy inter-
face to change any settings related to the wireless adapter. When
the computer is started, the "Configuration Utility" starts automati-
cally and the system tray icon is loaded in the toolbar. Clicking on
the utility icon will start the Configuration Utility. Another way to
start the Configuration Utility is to click on Start > Programs >
D-Link DWL-120 11Mbps WLAN > DWL-120 wireless
Configuration.
If the utility icon appears with a red "X" in the toolbar, then the utili-
ty did not install properly and will need to be reinstalled.
Sometimes the icon will be red which happens when the wireless
adapter is set to a different channel or the communication mode is
set incorrectly. Verify the settings for the D-Link Air product and
check that computer is within wireless range.
When the utility is started, the following screen will be displayed.
Figure 1 - Configuration Utility with opened "Status" tab
10

CONFIGURATION UTILITY
STATUS TAB
Link Status
The field will display the current state of the wireless adapter.
1. Associated - means that the wireless adapter is connected to
another wireless adapter or Access Point / Wireless Gateway
Router. The MAC address of the wireless adapter or Access Point
will be displayed in hex format i.e. BSS ID (Basic Service Set ID) =
00:40:05:AC:11:32. Networking is available when the wireless
adapter is associated to an Access point or another wireless
adapter.
2. Scanning - means that the node is searching for available
Access Point and trying to detect the SSID (Service Set ID) of an
Access Point within range.
NOTE: When the wireless is set to “Ad Hoc” mode, the wireless
adapter will scan for 5 seconds looking for an existing Ad Hoc net-
work using the same SSID. If one is not found the driver will
“Start” its own Ad Hoc network.
MAC
Displays the MAC address of the D-Link adapter product.
SSID (Service Set Identification)
Displays the current SSID setting of the D-Link Air adapter product.
Channel and Tx Rate
Shows the selected channel and transmit rate that are currently
used by the D-Link Air adapter for an active connection.
Tx/Rx Information
These two fields display the instantaneous wireless receive and
transmit throughput displayed in bytes per second. These values
are updated every two seconds.11

CONFIGURATION UTILITY
Signal Strength
The Signal Strength bar graph is only active when the node is in
Infrastructure Mode. The bar graph displays normalized signal
strength as reported by the radio, averaged over all frames over
100 bytes long that are received from the Access Point. A label
summarizes the quality of the link over the bar graph, which can
take on one of the following values:
"Not Applicable"
"Poor"
"Fair"
"Good"
"Excellent"
The D-Link Air adapter will start looking for a better Access Point if
the Link Quality becomes "Poor." Link Quality is a measure of
receive and transmit errors over the radio channel.
CONFIGURATION TAB
The Configuration Tab contains several fields where the operating
parameters of the D-Link Air product can be viewed and changed.
Changes to any of the parameters in the panel can be applied to
the wireless adapter without the need to reboot the PC.
12
Figure 2 - Configuration Utility with opened "Configuration" tab.

CONFIGURATION UTILITY
Change Configuration
Check the box to make changes to the default settings of the D-
Link Air product.
Update
Pressing the button applies and saves any settings that have been
changed for the D-Link Air product.
Station ESS ID (Extended Service Set Identifier)
The field allows the user to set the identification by typing the name
for a particular group of connected wireless adapters and Access
Point. The SSID has the name “default” as the initial settings after
the drivers are loaded. The D-Link Air product will be able to con-
nect to an Access Point with the same ESS ID.
13

CONFIGURATION UTILITY
Network Mode
The field allows selection from a list of supported Network
"Modes." The supported modes displayed are the following:
"Ad Hoc," and "Infrastructure." The default setting for the "Network
Mode" is "Infrastructure."
1. Ad Hoc - This is the 802.11b peer-to-peer mode of operation.
In "Ad Hoc" mode, only one wireless "cell" is supported for each
different SSID. All communication is done from client to client with-
out the use of an Access Point. "802.11b Ad Hoc" networking uses
the same SSID for the wireless adapters for establishing the net-
work connection. When “Ad Hoc” mode is selected the utility will
provide a selection for setting the channel.
14
Figure 3: “Configuration” tab with Network mode set to Ad Hoc.

CONFIGURATION UTILITY
2. Infrastructure - This mode of operation requires the presence
of an 802.11b Access Point. All communication is done through
the Access Point which relays packets to other wireless clients as
well as to nodes on a wired Ethernet network.
Preamble
The field allows two different selections: Long and Short. The
default setting for the “Preamble” field is set to “Long.”
1. Long - The mandatory supported “Long preamble as well as
header” as specified in IEEE 802.11b that allows interoperation
with the current 1Mbit/sec and 2Mbit/sec DSS (Direct Sequence
Spread Spectrum) specification.
2. Short - The optional “Short preamble and header” is intended
for applications where maximum throughput is desired and interop-
erability with legacy and non-short preamble capable equipment is
not a consideration.
Tx Rate
The transmission rate is set “1Mbit, 2Mbits, 5.5Mbits, as well as
11Mbits.”
15

CONFIGURATION UTILITY
ENCRYPTION TAB
16
Figure 3 - Configuration Utility with opened "Encryption" tab
If an additional measure of security is desired on the wireless net-
work, WEP (Wired Equivalent Privacy) encryption can be enabled.
WEP encrypts each frame transmitted from the wireless adapter
using one of the keys entered in the “WEP Key Entry” field.