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Appendix D Wireless LANs
AMG1202-T10A User’s Guide
277
Antenna Characteristics
Frequency
An antenna in the frequency of 2.4GHz (IEEE 802.11b and IEEE 802.11g) 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.
• Omni-directional antennas send the RF signal out in all directions on a horizontal plane. The
coverage area is torus-shaped (like a donut) which makes these antennas ideal for a room
environment. With a wide coverage area, it is possible to make circular overlapping coverage
areas with multiple access points.
• Directional antennas concentrate the RF signal in a beam, like a flashlight does with the light
from its bulb. The angle of the beam determines the width of the coverage pattern. Angles
typically range from 20 degrees (very directional) to 120 degrees (less directional). Directional
antennas are ideal for hallways and outdoor point-to-point applications.
Positioning Antennas
In general, antennas should be mounted as high as practically possible and free of obstructions. In
point-to–point application, position both antennas at the same height and in a direct line of sight to
each other to attain the best performance.
For omni-directional antennas mounted on a table, desk, and so on, point the antenna up. For
omni-directional antennas mounted on a wall or ceiling, point the antenna down. For a single AP
application, place omni-directional antennas as close to the center of the coverage area as possible.
For directional antennas, point the antenna in the direction of the desired coverage area.
Содержание AMG1202-T10A
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Страница 6: ...Document Conventions AMG1202 T10A User s Guide 6 Server Firewall Telephone Router Switch ...
Страница 8: ...Safety Warnings AMG1202 T10A User s Guide 8 ...
Страница 10: ...Contents Overview AMG1202 T10A User s Guide 10 ...
Страница 18: ...Table of Contents AMG1202 T10A User s Guide 18 ...
Страница 19: ...19 PART I User s Guide ...
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Страница 26: ...Chapter 1 Introduction AMG1202 T10A User s Guide 26 ...
Страница 32: ...Chapter 2 The Web Configurator AMG1202 T10A User s Guide 32 ...
Страница 36: ...Chapter 3 Status Screens AMG1202 T10A User s Guide 36 ...
Страница 53: ...53 PART II Technical Reference ...
Страница 54: ...54 ...
Страница 84: ...Chapter 6 WAN Setup AMG1202 T10A User s Guide 84 ...
Страница 96: ...Chapter 7 LAN Setup AMG1202 T10A User s Guide 96 ...
Страница 126: ...Chapter 8 Wireless LAN AMG1202 T10A User s Guide 126 ...
Страница 142: ...Chapter 10 Firewall AMG1202 T10A User s Guide 142 ...
Страница 148: ...Chapter 11 Filters AMG1202 T10A User s Guide 148 ...
Страница 152: ...Chapter 12 Static Route AMG1202 T10A User s Guide 152 ...
Страница 158: ...Chapter 13 802 1Q 1P AMG1202 T10A User s Guide 158 ...
Страница 166: ...Chapter 14 Quality of Service QoS AMG1202 T10A User s Guide 166 ...
Страница 202: ...Chapter 19 Logs AMG1202 T10A User s Guide 202 ...
Страница 223: ...Chapter 23 Product Specifications AMG1202 T10A User s Guide 223 ...
Страница 224: ...Chapter 23 Product Specifications AMG1202 T10A User s Guide 224 ...
Страница 264: ...Appendix C Pop up Windows JavaScripts and Java Permissions AMG1202 T10A User s Guide 264 ...
Страница 278: ...Appendix D Wireless LANs AMG1202 T10A User s Guide 278 ...
Страница 286: ...Appendix F Legal Information AMG1202 T10A User s Guide 286 ...
Страница 294: ...Index AMG1202 T10A User s Guide 294 ...
Страница 295: ...Index AMG1202 T10A User s Guide 295 ...
Страница 296: ...Index AMG1202 T10A User s Guide 296 ...