Appendix B Wireless LANs
NWA-3500/NWA-3550 User’s Guide
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Antenna Overview
An antenna couples RF signals onto air. A transmitter within a wireless device
sends an RF signal to the antenna, which propagates the signal through the air.
The antenna also operates in reverse by capturing RF signals from the air.
Positioning the antennas properly increases the range and coverage area of a
wireless LAN.
Antenna Characteristics
Frequency
An antenna in the frequency of 2.4GHz (IEEE 802.11b) or 5GHz(IEEE 802.11a) is
needed to communicate efficiently in a wireless LAN.
Radiation Pattern
A radiation pattern is a diagram that allows you to visualize the shape of the
antenna’s coverage area.
Antenna Gain
Antenna gain, measured in dB (decibel), is the increase in coverage within the RF
beam width. Higher antenna gain improves the range of the signal for better
communications.
For an indoor site, each 1 dB increase in antenna gain results in a range increase
of approximately 2.5%. For an unobstructed outdoor site, each 1dB increase in
gain results in a range increase of approximately 5%. Actual results may vary
depending on the network environment.
Antenna gain is sometimes specified in dBi, which is how much the antenna
increases the signal power compared to using an isotropic antenna. An isotropic
antenna is a theoretical perfect antenna that sends out radio signals equally well
in all directions. dBi represents the true gain that the antenna provides.
Types of Antennas for WLAN
There are two types of antennas used for wireless LAN applications.
Содержание 802.11a/g Wireless CardBus Card ZyXEL AG-120
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Страница 8: ...Safety Warnings NWA 3500 NWA 3550 User s Guide 8...
Страница 10: ...Contents Overview NWA 3500 NWA 3550 User s Guide 10...
Страница 20: ...Table of Contents NWA 3500 NWA 3550 User s Guide 20...
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Страница 34: ...Chapter 1 Introducing the NWA NWA 3500 NWA 3550 User s Guide 34...
Страница 52: ...Chapter 4 Management Mode NWA 3500 NWA 3550 User s Guide 52...
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Страница 146: ...Chapter 9 SSID Screen NWA 3500 NWA 3550 User s Guide 146...
Страница 160: ...Chapter 10 Wireless Security Screen NWA 3500 NWA 3550 User s Guide 160...
Страница 178: ...Chapter 14 IP Screen NWA 3500 NWA 3550 User s Guide 178...
Страница 186: ...Chapter 15 Rogue AP Detection NWA 3500 NWA 3550 User s Guide 186...
Страница 198: ...Chapter 16 Remote Management Screens NWA 3500 NWA 3550 User s Guide 198...
Страница 260: ...Chapter 21 Load Balancing NWA 3160 Series User s Guide 260...
Страница 264: ...Chapter 22 Dynamic Channel Selection NWA 3160 Series User s Guide 264...
Страница 276: ...Chapter 23 Maintenance NWA 3500 NWA 3550 User s Guide 276...
Страница 277: ...277 PART III Troubleshooting and Specifications Troubleshooting 279 Product Specifications 285...
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Страница 284: ...Chapter 24 Troubleshooting NWA 3500 NWA 3550 User s Guide 284...
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Страница 368: ...Appendix D Importing Certificates NWA 3500 NWA 3550 User s Guide 368...
Страница 386: ...Appendix F Text File Based Auto Configuration NWA 3500 NWA 3550 User s Guide 386...
Страница 396: ...Index NWA 3500 NWA 3550 User s Guide 396...