LINKSYS WUSB54GV2 Wireless-G USB Network Adapter User Manual Wusb54G ug Rev A

LINKSYS LLC Wireless-G USB Network Adapter Wusb54G ug Rev A

Contents

Users Manual Part 3

Can I run an application from a remote computer over the wireless network?
This will depend on whether or not the application is designed to be used over a
network. Consult the application’s user guide to determine if it supports operation
over a network.
Can I play computer games with other members of the wireless network?
Yes, as long as the game supports multiple players over a LAN (local area net-
work). Refer to the game’s user guide for more information.
What is the IEEE 802.11b standard?
It is one of the IEEE standards for wireless networks. The 802.11b standard allows
wireless networking hardware from different manufacturers to communicate, pro-
vided that the hardware complies with the 802.11b standard. The 802.11b standard
states a maximum data transfer rate of 11Mbps and an operating frequency of
2.4GHz.
What IEEE 802.11b features are supported?
The product supports the following IEEE 802.11b functions:
• CSMA/CA plus Acknowledge protocol
• Multi-Channel Roaming
• Automatic Rate Selection
• RTS/CTS feature
• Fragmentation
• Power Management
What is ad-hoc mode?
When a wireless network is set to ad-hoc mode, the wireless-equipped computers
are configured to communicate directly with each other. The ad-hoc wireless net-
work will not communicate with any wired network.
What is infrastructure mode?
When a wireless network is set to infrastructure mode, the wireless network is
configured to communicate with a wired network through a wireless access point.
What is roaming?
Roaming is the ability of a portable computer user to communicate continuously
while moving freely throughout an area greater than that covered by a single
access point. Before using the roaming function, the workstation must make sure
that it is the same channel number with the access point of dedicated coverage
area.
27
Appendix A: Troubleshooting
This chapter provides solutions to problems that may occur during the installa-
tion and operation of the Wireless-G USB Network Adapter. Read the descrip-
tions below to solve your problems. If you can’t find an answer here, check the
Linksys website at www.linksys.com.
1. My computer does not recognize the USB Network Adapter.
• Make sure that the USB Network Adapter is properly inserted into the USB
port.
• Also, make sure that the USB Controller is enabled in the BIOS. Check with
your motherboard User Guide for more information.
2. The USB Network Adapter does not work properly.
• Reinsert the USB Network Adapter into the notebook or desktop’s USB port.
• Right-click on My Computer, and select Properties. Select the Adapter,
then chose the Device Manager tab, and click on the Network Adapter. You
will find the USB Network Adapter if it is installed successfully. If you see
a yellow exclamation mark, the resources may be conflicting and you must
follow the steps below:
• Uninstall the driver software from your PC.
• Restart your PC and repeat the hardware and software installation as
specified in this User Guide.
3. I cannot communicate with the other computers linked via Ethernet in the
Infrastructure configuration.
• Make sure that the notebook or desktop is powered on.
• Make sure that your USB Network Adapter is configured on the same chan-
nel, SSID, and WEP as the other computers in the Infrastructure configura-
tion.
26
Frequently Asked Questions
Common Problems and Solutions
2928
Direct-Sequence Spread-Spectrum (DSSS) generates a redundant bit pattern
for each bit to be transmitted. This bit pattern is called a chip (or chipping
code). The longer the chip, the greater the probability that the original data can
be recovered. Even if one or more bits in the chip are damaged during trans-
mission, statistical techniques embedded in the radio can recover the original
data without the need for retransmission. To an unintended receiver, DSSS
appears as low power wideband noise and is rejected (ignored) by most nar-
rowband receivers.
Would the information be intercepted while transmitting on air?
WLAN features two-fold protection in security. On the hardware side, as with
Direct Sequence Spread Spectrum technology, it has the inherent security fea-
ture of scrambling. On the software side, WLAN offers the encryption function
(WEP) to enhance security and access control.
What is WEP?
WEP is Wired Equivalent Privacy, a data privacy mechanism based on a 64-bit
or 128-bit shared key algorithm, as described in the IEEE 802.11 standard.
To achieve true seamless connectivity, the wireless LAN must incorporate a
number of different functions. Each node and access point, for example, must
always acknowledge receipt of each message. Each node must maintain contact
with the wireless network even when not actually transmitting data. Achieving
these functions simultaneously requires a dynamic RF networking technology
that links access points and nodes. In such a system, the user’s end node under-
takes a search for the best possible access to the system. First, it evaluates such
factors as signal strength and quality, as well as the message load currently
being carried by each access point and the distance of each access point to the
wired backbone. Based on that information, the node next selects the right
access point and registers its address. Communications between end node and
host computer can then be transmitted up and down the backbone.
As the user moves on, the end node’s RF transmitter regularly checks the sys-
tem to determine whether it is in touch with the original access point or whether
it should seek a new one. When a node no longer receives acknowledgment
from its original access point, it undertakes a new search. Upon finding a new
access point, it then re-registers, and the communication process continues.
What is ISM band?
The FCC and their counterparts outside of the U.S. have set aside bandwidth
for unlicensed use in the ISM (Industrial, Scientific and Medical) band.
Spectrum in the vicinity of 2.4 GHz, in particular, is being made available
worldwide. This presents a truly revolutionary opportunity to place convenient
high-speed wireless capabilities in the hands of users around the globe.
What is Spread Spectrum?
Spread Spectrum technology is a wideband radio frequency technique devel-
oped by the military for use in reliable, secure, mission-critical communica-
tions systems. It is designed to trade off bandwidth efficiency for reliability,
integrity, and security. In other words, more bandwidth is consumed than in the
case of narrowband transmission, but the trade-off produces a signal that is, in
effect, louder and thus easier to detect, provided that the receiver knows the
parameters of the spread-spectrum signal being broadcast. If a receiver is not
tuned to the right frequency, a spread-spectrum signal looks like background
noise. There are two main alternatives, Direct Sequence Spread Spectrum
(DSSS) and Frequency Hopping Spread Spectrum (FHSS).
What is DSSS? What is FHSS? And what are their differences?
Frequency-Hopping Spread-Spectrum (FHSS) uses a narrowband carrier that
changes frequency in a pattern that is known to both transmitter and receiver.
Properly synchronized, the net effect is to maintain a single logical channel. To
an unintended receiver, FHSS appears to be short-duration impulse noise.
3130
Bit - A binary digit. The value - 0 or 1-used in the binary numbering system.
Also, the smallest form of data.
CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) - In local
area networking, this is the CSMA technique that combines slotted time-divi-
sion multiplexing with carrier sense multiple access/collision detection
(CSMA/CD) to avoid having collisions occur a second time. This works best if
the time allocated is short compared to packet length and if the number of sit-
uations is small.
CSMA/CD (Carrier Sense Multiple Access/Collision Detection) - The LAN
access method used in Ethernet. When a device wants to gain access to the net-
work, it checks to see if the network is quiet (senses the carrier). If it is not, it
waits a random amount of time before retrying. If the network is quiet and two
devices access the line at exactly the same time, their signals collide. When the
collision is detected, they both back off and each wait a random amount of time
before retrying.
CTS (Clear To Send) - An RS-232 signal sent from the receiving station to the
transmitting station that indicates it is ready to accept data.
Default Gateway - The routing device used to forward all traffic that is not
addressed to a station within the local subnet.
DHCP (Dynamic Host Configuration Protocol) - A protocol that lets network
administrators manage centrally and automate the assignment of Internet
Protocol (IP) addresses in an organization's network. Using the Internet's set of
protocol (TCP/IP), each machine that can connect to the Internet needs a
unique IP address. When an organization sets up its computer users with a con-
nection to the Internet, an IP address must be assigned to each machine.
Without DHCP, the IP address must be entered manually at each computer and,
if computers move to another location in another part of the network, a new IP
address must be entered. DHCP lets a network administrator supervise and dis-
tribute IP addresses from a central point and automatically sends a new IP
address when a computer is plugged into a different place in the network.
DHCP uses the concept of a "lease" or amount of time that a given IP address
will be valid for a computer. The lease time can vary depending on how long a
user is likely to require the Internet connection at a particular location. It's espe-
cially useful in education and other environments where users change fre-
quently. Using very short leases, DHCP can dynamically reconfigure networks
in which there are more computers than there are available IP addresses.
Appendix B: Glossary
802.11b - One of the IEEE standards for wireless networking hardware.
Products that adhere to a specific IEEE standard will work with each other,
even if they are manufactured by different companies. The 802.11b standard
specifies a maximum data transfer rate of 11Mbps, an operating frequency of
2.4GHz, and WEP encryption for security. 802.11b networks are also referred
to as Wi-Fi networks.
802.11g - A proposed, but as yet unratified extension of the IEEE 802.11 stan-
dard for wireless networking hardware. The draft 802.11g specifications used
by Linksys specify a maximum data transfer rate of 54Mbps using OFDM
modulation, an operating frequency of 2.4GHz, backward compatibility with
IEEE 802.11b devices, and WEP encryption for security.
Adapter - Printed circuit board that plugs into a PC to add to capabilities or
connectivity to a PC. In a networked environment, a network interface card is
the typical adapter that allows the PC or server to connect to the intranet and/or
Internet.
Ad-hoc Network - An ad-hoc network is a group of computers, each with a
wireless adapter, connected as an independent 802.11 wireless LAN. Ad-hoc
wireless computers operate on a peer-to-peer basis, communicating directly
with each other without the use of an access point. Ad-hoc mode is also
referred to as an Independent Basic Service Set or as peer-to-peer mode.
Automatic Fall-back - A feature provided by some wireless products to
increase connection reliability. Automatic fall-back enables a device to dynam-
ically shift between various data transfer rates. It works by decreasing the data
transfer rate when interference increases, distance increases, and other factors
undermine signal strength and quality.
Backbone - The part of a network that connects most of the systems and net-
works together and handles the most data.
Bandwidth - The transmission capacity of a given facility, in terms of how
much data the facility can transmit in a fixed amount of time; expressed in bits
per second (bps).
3332
Fragmentation - Breaking a packet into smaller units when transmitting over
a network medium that cannot support the original size of the packet.
Gateway - A device that interconnects networks with different, incompatible
communications protocols.
Hardware - Hardware is the physical aspect of computers, telecommunica-
tions, and other information technology devices. The term arose as a way to dis-
tinguish the "box" and the electronic circuitry and components of a computer
from the program you put in it to make it do things. The program came to be
known as the software.
Hop - The link between two network nodes.
IEEE (The Institute of Electrical and Electronics Engineers) - The IEEE
describes itself as "the world's largest technical professional society, promoting
the development and application of electrotechnology and allied sciences for
the benefit of humanity, the advancement of the profession, and the well-being
of our members."
The IEEE fosters the development of standards that often become national and
international standards. The organization publishes a number of journals, has
many local chapters, and several large societies in special areas, such as the
IEEE Computer Society.
Infrastructure Network - An infrastructure network is a group of computers
or other devices, each with a wireless adapter, connected as an 802.11 wireless
LAN. In infrastructure mode, the wireless devices communicate with each
other and to a wired network by first going through an access point. An infra-
structure wireless network connected to a wired network is referred to as a
Basic Service Set. A set of two or more BSS in a single network is referred to
as an Extended Service Set. Infrastructure mode is useful at a corporation
scale, or when it is necessary to connect the wired and wireless networks.
IP (Internet Protocol) - The method or protocol by which data is sent from one
computer to another on the Internet. It is a standard set of rules, procedures, or
conventions relating to the format and timing of data transmission between two
computers that they must accept and use to be able to understand each other.
IP Address - In the most widely installed level of the Internet Protocol (IP)
today, an IP address is a 32-binary digit number that identifies each sender or
receiver of information that is sent in packet across the Internet. When you
DHCP supports static addresses for computers containing Web servers that
need a permanent IP address.
DNS - The domain name system (DNS) is the way that Internet domain name
are located and translated into Internet Protocol (IP) addresses. A domain name
is a meaningful and easy-to-remember "handle" for an Internet address.
Domain - A subnetwork comprised of a group of clients and servers under the
control of one security database. Dividing LANs into domains improves per-
formance and security.
Driver - A workstation or server software module that provides an interface
between a network interface card and the upper-layer protocol software running
in the computer; it is designed for a specific device, and is installed during the
initial installation of a network-compatible client or server operating system.
DSSS (Direct-Sequence Spread Spectrum) - DSSS generates a redundant bit
pattern for all data transmitted. This bit pattern is called a chip (or chipping
code). Even if one or more bits in the chip are damaged during transmission,
statistical techniques embedded in the receiver can recover the original data
without the need for retransmission. To an unintended receiver, DSSS appears
as low power wideband noise and is rejected (ignored) by most narrowband
receivers. However, to an intended receiver (i.e. another wireless LAN end-
point), the DSSS signal is recognized as the only valid signal, and interference
is inherently rejected (ignored).
Encryption - A security method that applies a specific algorithm to data in
order to alter the data's appearance and prevent other devices from reading the
information.
Ethernet - IEEE standard network protocol that specifies how data is placed
on and retrieved from a common transmission medium. Has a transfer rate of
10 Mbps. Forms the underlying transport vehicle used by several upper-level
protocols, including TCP/IP and XNS.
FHSS (Frequency Hopping Spread Spectrum) - FHSS continuously changes
(hops) the carrier frequency of a conventional carrier several times per second
according to a pseudo-random set of channels. Because a fixed frequency is not
used, and only the transmitter and receiver know the hop patterns, interception
of FHSS is extremely difficult.
OFDM - Developed for wireless applications, Orthogonal Frequency Division
Multiplexing (OFDM) technology offers superior performance--increased data
rates and more reliable transmissions--than previous technologies, such as
DSSS. OFDM is a scheme in which numerous signals of different frequencies
are combined to form a single signal for transmission on the medium.
OFDM works by breaking one high-speed data stream into a number of lower-
speed data streams, which are then transmitted in parallel. Each lower speed
stream is used to modulate a subcarrier. Essentially, this creates a multi-carrier
transmission by dividing a wide frequency band or channel into a number of
narrower frequency bands or sub-channels. OFDM is also used for other appli-
cations, including powerline networking.
Packet - A unit of data routed between an origin and a destination in a network.
Packet Filtering - Discarding unwanted network traffic based on its originating
address or range of addresses or its type (e-mail, file transfer, etc.).
Passphrase - Used much like a password, a passphrase simplifies the WEP
encryption process by automatically generating the WEP encryption keys for
Linksys products.
Plug-and-Play - The ability of a computer system to configure expansion
boards and other devices automatically without requiring the user to turn off
the system during installation.
Port - A pathway into and out of the computer or a network device. For exam-
ple, the serial and parallel ports on a personal computer are external sockets for
plugging in communications lines, modems and printers.
Roaming - In an infrastructure mode wireless network, this refers to the abili-
ty to move out of one access point's range and into another and transparently
reassociate and reauthenticate to the new access point. This reassociation and
reauthentication should occur without user intervention and ideally without
interruption to network connectivity. A typical scenario would be a location
with multiple access points, where users can physically relocate from one area
to another and easily maintain connectivity.
RTS (Request To Send) - An RS-232 signal sent from the transmitting station
to the receiving station requesting permission to transmit.
3534
request an HTML page or send e-mail, the Internet Protocol part of TCP/IP
includes your IP address in the message (actually, in each of the packets if more
than one is required) and sends it to the IP address that is obtained by looking
up the domain name in the Uniform Resource Locator you requested or in the
e-mail address you're sending a note to. At the other end, the recipient can see
the IP address of the Web page requestor or the e-mail sender and can respond
by sending another message using the IP address it received.
ISM band - The FCC and their counterparts outside of the U.S. have set aside
bandwidth for unlicensed use in the ISM (Industrial, Scientific and Medical)
band. Spectrum in the vicinity of 2.4 GHz, in particular, is being made avail-
able worldwide. This presents a truly revolutionary opportunity to place con-
venient high-speed wireless capabilities in the hands of users around the globe.
LAN (Local Area Network) - A group of computers and associated devices that
share a common communications line and typically share the resources of a
single processor or server within a small geographic area (for example, within
an office building).
MAC (Media Access Control) Address - A unique number assigned by the
manufacturer to any Ethernet networking device, such as a network adapter,
that allows the network to identify it at the hardware level.
Mbps (Megabits per second) - One million bits per second; unit of measure-
ment for data transmission.
Motherboard - A motherboard is the physical arrangement in a computer that
contains the computer's basic circuitry and components.
Network - A system that transmits any combination of voice, video and/or data
between users.
Node - A network junction or connection point, typically a computer or work
station.
Notebook (PC) - A notebook computer is a battery-powered personal comput-
er generally smaller than a briefcase that can easily be transported and conve-
niently used in temporary spaces such as on airplanes, in libraries, temporary
offices, and at meetings. A notebook computer, sometimes called a laptop com-
puter, typically weighs less than five pounds and is three inches or less in thick-
ness.
of the data (routing), TCP takes care of keeping track of the individual units of
data (called packets) that a message is divided into for efficient delivery over
the network. TCP is known as a "connection oriented" protocol due to requir-
ing the receiver of a packet to return an acknowledgment of receipt to the
sender of the packet resulting in transmission control.
TCP/IP (Transmission Control Protocol/Internet Protocol) - The basic com-
munication language or set of protocols for communications over a network
(developed specifically for the Internet). TCP/IP defines a suite or group of
protocols and not only TCP and IP.
Topology - A network's topology is a logical characterization of how the
devices on the network are connected and the distances between them. The
most common network devices include hubs, switches, routers, and gateways.
Most large networks contain several levels of interconnection, the most impor-
tant of which include edge connections, backbone connections, and wide-area
connections.
USB (Universal Serial Bus) - A "plug-and-play" interface between a comput-
er and peripherals, such as digital cameras, scanners, game controllers, speak-
ers, keyboards, portable data storage, or printers. With USB, you can add a new
peripheral to your computer without having to add an adapter card or powering
down the computer. USB also supports hot-swapping, the addition or removal
of devices while the computer is running.
USB 1.1-compliant devices support data rates of 1.5Mbps (low-speed) and up
to 12Mbps (full-speed). USB 2.0-compliant devices are backward compatible
with earlier USB devices, and they support data rates of 1.5Mbps (low-speed),
12Mbps (full-speed), and up to 480Mbps (high-speed).
WEP (Wired Equivalent Privacy) - A data privacy mechanism based on a 64-
bit or 128-bit shared key algorithm, as described in the IEEE 802.11 standard.
WLAN (Wireless Local Area Network) - A group of computers and associat-
ed devices that communicate with each other wirelessly.
37
Server - Any computer whose function in a network is to provide user access
to files, printing, communications, and other services.
Software - Instructions for the computer. A series of instructions that performs
a particular task is called a "program." The two major categories of software are
"system software" and "application software." System software is made up of
control programs such as the operating system and database management sys-
tem (DBMS). Application software is any program that processes data for the
user.
A common misconception is that software is data. It is not. Software tells the
hardware how to process the data.
Spread Spectrum - Spread Spectrum technology is a wideband radio frequen-
cy technique developed by the military for use in reliable, secure, mission-crit-
ical communications systems. It is designed to trade off bandwidth efficiency
for reliability, integrity, and security. In other words, more bandwidth is con-
sumed than in the case of narrowband transmission, but the trade off produces
a signal that is, in effect, louder and thus easier to detect, provided that the
receiver knows the parameters of the spread-spectrum signal being broadcast.
If a receiver is not tuned to the right frequency, a spread-spectrum signal looks
like background noise. There are two main alternatives, Direct Sequence
Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).
SSID (Service Set IDentifier) - A unique name shared among all points in a
wireless network. The SSID must be identical for each point in the wireless net-
work and is case-sensitive.
Storage - The semi-permanent or permanent holding place for digital data.
Subnet Mask - The method used for splitting IP networks into a series of sub-
groups, or subnets. The mask is a binary pattern that is matched up with the IP
address to turn part of the host ID address field into a field for subnets.
Switch - 1. A data switch connects computing devices to host computers,
allowing a large number of devices to share a limited number of ports. 2. A
device for making, breaking, or changing the connections in an electrical cir-
cuit.
TCP (Transmission Control Protocol) - A method (protocol) used along with
the IP (Internet Protocol) to send data in the form of message units (datagram)
between network devices. While IP takes care of handling the actual delivery
36
Dimensions 3.58" x 2.8" x 0.91"
(91 mm x 71 mm x 23 mm)
Unit Weight .18 lbs. (.08 kg)
Certifications FCC
Operating Temp. 32ºF to 104ºF (0ºC to 40ºC)
Storage Temp. 0ºF to 70ºF (-40ºC to 185ºC)
Operating Humidity 10% to 85%, Non-Condensing
Storage Humidity 5% to 90%, Non-Condensing
3938
Environmental
Appendix C: Specifications
Standards IEEE 802.11b, IEEE 802.11g, USB 1.1, USB 2.0
Ports USB Port
Channels 802.11b/ 802.11g
11 Channels (US, Canada)
13 Channels (Europe)
14 Channels (Japan)
LEDs Power, Link
Transmitted Power 16dBm (Typical)@11M CCK,
14dBm (Typical)@54M OFDM
Receive Sensitivity -65dBm@54Mbps
Antenna 2dBi
Security Features WEP Encryption
WEP key bits 64, 128-bit
Warranty 3 Year
Cisco-Linksys, LLC declares that WUSB54Gv2 ( FCC ID: Q87-WUSB54GV2 ) is limited in CH1~CH11 by specified 
firmware controlled in U.S.A.

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