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 anetwork. Consult the application’s user guide to determine if it supports operationover 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 allowswireless networking hardware from different manufacturers to communicate, pro-vided that the hardware complies with the 802.11b standard. The 802.11b standardstates a maximum data transfer rate of 11Mbps and an operating frequency of2.4GHz.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 computersare 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 isconfigured 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 continuouslywhile moving freely throughout an area greater than that covered by a singleaccess point. Before using the roaming function, the workstation must make surethat it is the same channel number with the access point of dedicated coveragearea. 27Appendix A: TroubleshootingThis 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 theLinksys 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 USBport.• Also, make sure that the USB Controller is enabled in the BIOS. Check withyour 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. Youwill find the USB Network Adapter if it is installed successfully. If you seea yellow exclamation mark, the resources may be conflicting and you mustfollow the steps below:• Uninstall the driver software from your PC.• Restart your PC and repeat the hardware and software installation asspecified in this User Guide.3. I cannot communicate with the other computers linked via Ethernet in theInfrastructure 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.26Frequently Asked QuestionsCommon Problems and Solutions
2928Direct-Sequence Spread-Spectrum (DSSS) generates a redundant bit patternfor each bit to be transmitted. This bit pattern is called a chip (or chippingcode). The longer the chip, the greater the probability that the original data canbe recovered. Even if one or more bits in the chip are damaged during trans-mission, statistical techniques embedded in the radio can recover the originaldata without the need for retransmission. To an unintended receiver, DSSSappears 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 withDirect 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-bitor 128-bit shared key algorithm, as described in the IEEE 802.11 standard.To achieve true seamless connectivity, the wireless LAN must incorporate anumber of different functions. Each node and access point, for example, mustalways acknowledge receipt of each message. Each node must maintain contactwith the wireless network even when not actually transmitting data. Achievingthese functions simultaneously requires a dynamic RF networking technologythat 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 suchfactors as signal strength and quality, as well as the message load currentlybeing carried by each access point and the distance of each access point to thewired backbone. Based on that information, the node next selects the rightaccess point and registers its address. Communications between end node andhost 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 whetherit should seek a new one. When a node no longer receives acknowledgmentfrom its original access point, it undertakes a new search. Upon finding a newaccess 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 bandwidthfor unlicensed use in the ISM (Industrial, Scientific and Medical) band.Spectrum in the vicinity of 2.4 GHz, in particular, is being made availableworldwide. This presents a truly revolutionary opportunity to place convenienthigh-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 thecase of narrowband transmission, but the trade-off produces a signal that is, ineffect, louder and thus easier to detect, provided that the receiver knows theparameters of the spread-spectrum signal being broadcast. If a receiver is nottuned to the right frequency, a spread-spectrum signal looks like backgroundnoise. 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 thatchanges frequency in a pattern that is known to both transmitter and receiver.Properly synchronized, the net effect is to maintain a single logical channel. Toan unintended receiver, FHSS appears to be short-duration impulse noise.
3130Bit - 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 localarea 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 ifthe 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 LANaccess 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, itwaits a random amount of time before retrying. If the network is quiet and twodevices access the line at exactly the same time, their signals collide. When thecollision is detected, they both back off and each wait a random amount of timebefore retrying.CTS (Clear To Send) - An RS-232 signal sent from the receiving station to thetransmitting station that indicates it is ready to accept data.Default Gateway - The routing device used to forward all traffic that is notaddressed to a station within the local subnet.DHCP (Dynamic Host Configuration Protocol) - A protocol that lets networkadministrators manage centrally and automate the assignment of InternetProtocol (IP) addresses in an organization's network. Using the Internet's set ofprotocol (TCP/IP), each machine that can connect to the Internet needs aunique 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 IPaddress must be entered. DHCP lets a network administrator supervise and dis-tribute IP addresses from a central point and automatically sends a new IPaddress 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 addresswill be valid for a computer. The lease time can vary depending on how long auser 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 networksin which there are more computers than there are available IP addresses. Appendix B: Glossary802.11b - 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 standardspecifies a maximum data transfer rate of 11Mbps, an operating frequency of2.4GHz, and WEP encryption for security. 802.11b networks are also referredto 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 usedby Linksys specify a maximum data transfer rate of 54Mbps using OFDMmodulation, an operating frequency of 2.4GHz, backward compatibility withIEEE 802.11b devices, and WEP encryption for security.Adapter - Printed circuit board that plugs into a PC to add to capabilities orconnectivity to a PC. In a networked environment, a network interface card isthe typical adapter that allows the PC or server to connect to the intranet and/orInternet.Ad-hoc Network - An ad-hoc network is a group of computers, each with awireless adapter, connected as an independent 802.11 wireless LAN. Ad-hocwireless computers operate on a peer-to-peer basis, communicating directlywith each other without the use of an access point. Ad-hoc mode is alsoreferred to as an Independent Basic Service Set or as peer-to-peer mode.Automatic Fall-back - A feature provided by some wireless products toincrease connection reliability. Automatic fall-back enables a device to dynam-ically shift between various data transfer rates. It works by decreasing the datatransfer rate when interference increases, distance increases, and other factorsundermine 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 howmuch data the facility can transmit in a fixed amount of time; expressed in bitsper second (bps).
3332Fragmentation - Breaking a packet into smaller units when transmitting overa network medium that cannot support the original size of the packet. Gateway - A device that interconnects networks with different, incompatiblecommunications 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 computerfrom the program you put in it to make it do things. The program came to beknown as the software.Hop - The link between two network nodes.IEEE (The Institute of Electrical and Electronics Engineers) - The IEEEdescribes itself as "the world's largest technical professional society, promotingthe development and application of electrotechnology and allied sciences forthe benefit of humanity, the advancement of the profession, and the well-beingof our members." The IEEE fosters the development of standards that often become national andinternational standards. The organization publishes a number of journals, hasmany local chapters, and several large societies in special areas, such as theIEEE Computer Society.Infrastructure Network - An infrastructure network is a group of computersor other devices, each with a wireless adapter, connected as an 802.11 wirelessLAN. In infrastructure mode, the wireless devices communicate with eachother 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 aBasic Service Set. A set of two or more BSS in a single network is referred toas an Extended Service Set. Infrastructure mode is useful at a corporationscale, 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 onecomputer to another on the Internet. It is a standard set of rules, procedures, orconventions relating to the format and timing of data transmission between twocomputers 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 orreceiver of information that is sent in packet across the Internet. When youDHCP supports static addresses for computers containing Web servers thatneed a permanent IP address. DNS - The domain name system (DNS) is the way that Internet domain nameare located and translated into Internet Protocol (IP) addresses. A domain nameis a meaningful and easy-to-remember "handle" for an Internet address. Domain - A subnetwork comprised of a group of clients and servers under thecontrol of one security database. Dividing LANs into domains improves per-formance and security.Driver - A workstation or server software module that provides an interfacebetween a network interface card and the upper-layer protocol software runningin the computer; it is designed for a specific device, and is installed during theinitial installation of a network-compatible client or server operating system.DSSS (Direct-Sequence Spread Spectrum) - DSSS generates a redundant bitpattern for all data transmitted. This bit pattern is called a chip (or chippingcode). Even if one or more bits in the chip are damaged during transmission,statistical techniques embedded in the receiver can recover the original datawithout the need for retransmission. To an unintended receiver, DSSS appearsas low power wideband noise and is rejected (ignored) by most narrowbandreceivers. However, to an intended receiver (i.e. another wireless LAN end-point), the DSSS signal is recognized as the only valid signal, and interferenceis inherently rejected (ignored).Encryption - A security method that applies a specific algorithm to data inorder to alter the data's appearance and prevent other devices from reading theinformation. Ethernet - IEEE standard network protocol that specifies how data is placedon and retrieved from a common transmission medium. Has a transfer rate of10 Mbps. Forms the underlying transport vehicle used by several upper-levelprotocols, including TCP/IP and XNS.FHSS (Frequency Hopping Spread Spectrum) - FHSS continuously changes(hops) the carrier frequency of a conventional carrier several times per secondaccording to a pseudo-random set of channels. Because a fixed frequency is notused, and only the transmitter and receiver know the hop patterns, interceptionof FHSS is extremely difficult.
OFDM - Developed for wireless applications, Orthogonal Frequency DivisionMultiplexing (OFDM) technology offers superior performance--increased datarates and more reliable transmissions--than previous technologies, such asDSSS. OFDM is a scheme in which numerous signals of different frequenciesare 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 speedstream is used to modulate a subcarrier. Essentially, this creates a multi-carriertransmission by dividing a wide frequency band or channel into a number ofnarrower 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 originatingaddress or range of addresses or its type (e-mail, file transfer, etc.). Passphrase - Used much like a password, a passphrase simplifies the WEPencryption process by automatically generating the WEP encryption keys forLinksys products.Plug-and-Play - The ability of a computer system to configure expansionboards and other devices automatically without requiring the user to turn offthe 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 forplugging 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 transparentlyreassociate and reauthenticate to the new access point. This reassociation andreauthentication should occur without user intervention and ideally withoutinterruption to network connectivity. A typical scenario would be a locationwith multiple access points, where users can physically relocate from one areato another and easily maintain connectivity.RTS (Request To Send) - An RS-232 signal sent from the transmitting stationto the receiving station requesting permission to transmit. 3534request an HTML page or send e-mail, the Internet Protocol part of TCP/IPincludes your IP address in the message (actually, in each of the packets if morethan one is required) and sends it to the IP address that is obtained by lookingup the domain name in the Uniform Resource Locator you requested or in thee-mail address you're sending a note to. At the other end, the recipient can seethe IP address of the Web page requestor or the e-mail sender and can respondby sending another message using the IP address it received. ISM band - The FCC and their counterparts outside of the U.S. have set asidebandwidth 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 thatshare a common communications line and typically share the resources of asingle processor or server within a small geographic area (for example, withinan office building). MAC (Media Access Control) Address - A unique number assigned by themanufacturer 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 thatcontains the computer's basic circuitry and components. Network - A system that transmits any combination of voice, video and/or databetween users. Node - A network junction or connection point, typically a computer or workstation.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, temporaryoffices, 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 ofdata (called packets) that a message is divided into for efficient delivery overthe 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 thesender 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 ofprotocols and not only TCP and IP.Topology - A network's topology is a logical characterization of how thedevices on the network are connected and the distances between them. Themost 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-areaconnections.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 newperipheral to your computer without having to add an adapter card or poweringdown the computer. USB also supports hot-swapping, the addition or removalof devices while the computer is running.USB 1.1-compliant devices support data rates of 1.5Mbps (low-speed) and upto 12Mbps (full-speed). USB 2.0-compliant devices are backward compatiblewith 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.37Server - Any computer whose function in a network is to provide user accessto files, printing, communications, and other services. Software - Instructions for the computer. A series of instructions that performsa particular task is called a "program." The two major categories of software are"system software" and "application software." System software is made up ofcontrol programs such as the operating system and database management sys-tem (DBMS). Application software is any program that processes data for theuser.A common misconception is that software is data. It is not. Software tells thehardware 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 efficiencyfor reliability, integrity, and security. In other words, more bandwidth is con-sumed than in the case of narrowband transmission, but the trade off producesa signal that is, in effect, louder and thus easier to detect, provided that thereceiver knows the parameters of the spread-spectrum signal being broadcast.If a receiver is not tuned to the right frequency, a spread-spectrum signal lookslike background noise. There are two main alternatives, Direct SequenceSpread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).SSID (Service Set IDentifier) - A unique name shared among all points in awireless 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 IPaddress 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. Adevice for making, breaking, or changing the connections in an electrical cir-cuit.TCP (Transmission Control Protocol) - A method (protocol) used along withthe IP (Internet Protocol) to send data in the form of message units (datagram)between network devices. While IP takes care of handling the actual delivery36
Dimensions 3.58" x 2.8" x 0.91" (91 mm x 71 mm x 23 mm)Unit Weight .18 lbs. (.08 kg)Certifications FCCOperating Temp. 32ºF to 104ºF (0ºC to 40ºC) Storage Temp. 0ºF to 70ºF (-40ºC to 185ºC) Operating Humidity 10% to 85%, Non-CondensingStorage Humidity 5% to 90%, Non-Condensing 3938EnvironmentalAppendix C: SpecificationsStandards IEEE 802.11b, IEEE 802.11g, USB 1.1, USB 2.0Ports USB PortChannels 802.11b/ 802.11g11 Channels (US, Canada)13 Channels (Europe)14 Channels (Japan)LEDs Power, LinkTransmitted Power 16dBm (Typical)@11M CCK,14dBm (Typical)@54M OFDMReceive Sensitivity -65dBm@54MbpsAntenna 2dBiSecurity Features WEP EncryptionWEP key bits 64, 128-bitWarranty 3 YearCisco-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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