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Appendix E Wireless LANs
ZyXEL NWA-1100 User’s Guide
171
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 NWA-1100
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Страница 8: ...Safety Warnings ZyXEL NWA 1100 User s Guide 8 ...
Страница 10: ...Contents Overview ZyXEL NWA 1100 User s Guide 10 ...
Страница 16: ...Table of Contents ZyXEL NWA 1100 User s Guide 16 ...
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Страница 32: ...Chapter 2 Introducing the Web Configurator ZyXEL NWA 1100 User s Guide 32 ...
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Страница 54: ...Chapter 5 System Screens ZyXEL NWA 1100 User s Guide 54 ...
Страница 72: ...Chapter 6 Wireless Settings Screen ZyXEL NWA 1100 User s Guide 72 ...
Страница 92: ...Chapter 8 RADIUS Screen ZyXEL NWA 1100 User s Guide 92 ...
Страница 96: ...Chapter 9 MAC Filter Screen ZyXEL NWA 1100 User s Guide 96 ...
Страница 100: ...Chapter 10 IP Screen ZyXEL NWA 1100 User s Guide 100 ...
Страница 136: ...Chapter 15 Troubleshooting ZyXEL NWA 1100 User s Guide 136 ...
Страница 138: ...138 ...
Страница 142: ...Appendix B Power over Ethernet PoE Specifications ZyXEL NWA 1100 User s Guide 142 ...
Страница 144: ...Appendix C Power Adaptor Specifications ZyXEL NWA 1100 User s Guide 144 ...
Страница 198: ...Appendix H Text File Based Auto Configuration ZyXEL NWA 1100 User s Guide 198 ...
Страница 214: ...Appendix J Open Software Announcements ZyWALL USG 300 User s Guide 214 ...
Страница 225: ...Index ZyXEL NWA 1100 User s Guide 225 ...