Linksys WUSB200 manual What is ISM band?

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Wireless-G Business USB Network Adapter with RangeBooster

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.

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 undertakes 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 system 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 developed by the military for use in reliable, secure, mission-critical communications 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. 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

Appendix A: Troubleshooting

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Frequently Asked Questions

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Contents Wireless-G Business USB Network Adapter with RangeBooster Copyright and Trademarks How to Use this User GuideTable of Contents Windows XP Wireless Zero Configuration Appendix C Wireless SecurityLEDs List of FiguresCreating a Profile WEP Key Needed 43 Editing a Profile Congratulations Welcome IntroductionWhat’s in this User Guide? Wireless-G Business USB Network Adapter with RangeBooster Roaming Planning your Wireless NetworkNetwork Topology Network Layout LED Indicators Getting to Know the Wireless-G Business USB Network AdapterSetup Wizard’s Welcome Screen Starting the SetupSetup Wizard’s License Agreement Connecting the AdapterAvailable Wireless Network Setting up the AdapterWEP WPA2-Personal WPA-Personal10 Creating a Profile Manual Setup12 Ad-Hoc Mode Settings 14 Wireless Security WPA Personal TLS EAP-TLS WPA EnterpriseWPA2 Enterprise 20 Wireless Security Radius EAP-TLSRadius Link Information Using the Wireless Network MonitorAccessing the Wireless Network Monitor Using the Wireless Network MonitorsStatus Link Information Wireless Network StatusStatistics Link Information Wireless Network StatisticsProfile Information ProfilesCreate a New Profile Creating a Profile Available Wireless Network10 Creating a Profile WPA-Personal 12 Creating a Profile Manual Setup Network Settings 15 Creating a Profile Manual Setup Wireless Security WEP Using the Wireless Network Monitor Create a New Profile WPA Enterprise WPA2 Enterprise Radius 24 Creating a Profile Manual Setup Wireless Security Leap Editing a Profile 26 Creating a Profile Manual Setup Congratulations29 Editing a Profile Ad Hoc Mode WEP 32 Editing a Profile Wireless Security WPA Personal 35 Editing a Profile Wireless Security WPA Enterprise Peap 37 Editing a Profile Wireless Security WPA2 Enterprise Peap Radius EAP-TLS Leap 43 Editing a Profile Congratulations Site Information Site SurveyAdministration TroubleshootingLog in as the Access Points administrator Access Point Account49 Administration Security Monitor Account Classification Administrative Functions in the Wireless Network MonitorAP Classification ClassificationTrusted MAC Addresses Advanced SettingsAllowed Vendor List Configuration Channel Usage Allowed Channel ConfigurationSecurity Monitor Client Inventory AP InventoryAlerts Summary AlertAlert Details Alert List18 Security Monitor Alert Advice AdviceDisassociation attacking Alert Description Advice Legitimate AP Attacks or sniffing AP does not have any encryption Updated Client computers Ssid and MAC address 19 Security Monitor Windows Firewall Screen Windows FirewallCommon Problems and Solutions Appendix a TroubleshootingCan users turn off the pop-up alerts? Frequently Asked QuestionsWhat is the 802.11b standard? What is ISM band? What is WEP? Windows XP Wireless Zero Configuration Appendix B Windows XP Wireless Zero ConfigurationFigure B-4 Available Wireless Network Figure B-6 Network Connection Wireless Security Security Threats Facing Wireless Networks Appendix C Wireless SecuritySecurity Precautions Appendix C Wireless Security Wireless-G Business USB Network Adapter with RangeBooster Network Neighborhood/My Network Places Appendix D Windows HelpShared Resources Appendix E Glossary Wireless-G Business USB Network Adapter with RangeBooster Wireless-G Business USB Network Adapter with RangeBooster Wireless-G Business USB Network Adapter with RangeBooster Wireless-G Business USB Network Adapter with RangeBooster Appendix F Specifications Operating Humidity Unit Weight 15 oz 0.061 kg CertificationsOperating Temp Storage TempLimited Warranty Appendix G Warranty InformationFCC Statement Appendix H Regulatory InformationWireless-N Notebook Adapter Dual-Band Wireless-N Notebook Adapter Dual-Band Wireless-N Notebook Adapter Dual-Band Wireless-N Notebook Adapter Dual-Band Wireless-N Notebook Adapter Wireless-N Notebook Adapter Appendix I Contact Information
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