ZyAIR G-3000 User’s Guide
Appendix M Antenna Selection and Positioning Recommendation
216
Appendix M
Antenna Selection and Positioning
Recommendation
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.
Choosing the right antennas and positioning them 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.
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Страница 1: ...ZyAIR G 3000 802 11g Business Access Point Bridge Repeater User s Guide Version 3 50 September 2004...
Страница 14: ...ZyAIR G 3000 User s Guide 15 Table of Contents...
Страница 22: ...ZyAIR G 3000 User s Guide 23 List of Tables...
Страница 26: ...ZyAIR G 3000 User s Guide 27 Preface...
Страница 40: ...ZyAIR G 3000 User s Guide 41 Chapter 2 Introducing the Web Configurator...
Страница 48: ...ZyAIR G 3000 User s Guide 49 Chapter 3 Wizard Setup...
Страница 54: ...ZyAIR G 3000 User s Guide 55 Chapter 4 System Screens...
Страница 100: ...ZyAIR G 3000 User s Guide 101 Chapter 8 IP Screen...
Страница 116: ...ZyAIR G 3000 User s Guide 117 Chapter 10 Maintenance Figure 59 Restart Screen...
Страница 122: ...ZyAIR G 3000 User s Guide 123 Chapter 11 Introducing the SMT...
Страница 132: ...ZyAIR G 3000 User s Guide 133 Chapter 13 LAN Setup...
Страница 174: ...ZyAIR G 3000 User s Guide 175 Appendix C Power over Ethernet Specifications...
Страница 176: ...ZyAIR G 3000 User s Guide 177 Appendix D Brute Force Password Guessing Protection...
Страница 188: ...ZyAIR G 3000 User s Guide 189 Appendix E Setting up Your Computer s IP Address...
Страница 192: ...ZyAIR G 3000 User s Guide 193 Appendix F IP Address Assignment Conflicts...
Страница 200: ...ZyAIR G 3000 User s Guide 201 Appendix G IP Subnetting...
Страница 202: ...ZyAIR G 3000 User s Guide 203 Appendix H Command Interpreter...
Страница 206: ...ZyAIR G 3000 User s Guide 207 Appendix I Log Descriptions...
Страница 209: ...ZyAIR G 3000 User s Guide Appendix J Wireless LAN and IEEE 802 11 210 Figure 127 ESS Provides Campus Wide Coverage...
Страница 210: ...ZyAIR G 3000 User s Guide 211 Appendix J Wireless LAN and IEEE 802 11...