Chapter 7 Wireless
•If two wireless networks overlap, they should use a different channel.
Like radio stations or television channels, each wireless network uses a specific channel, or frequency, to send and receive information.
•Every device in the same wireless network must use security compatible with the AP.
Security stops unauthorized devices from using the wireless network. It can also protect the information that is sent in the wireless network.
Radio Channels
In the radio spectrum, there are certain frequency bands allocated for unlicensed, civilian use. For the purposes of wireless networking, these bands are divided into numerous channels. This allows a variety of networks to exist in the same place without interfering with one another. When you create a network, you must select a channel to use.
Since the available unlicensed spectrum varies from one country to another, the number of available channels also varies.
7.9.2 Additional Wireless Terms
The following table describes some wireless network terms and acronyms used in the ZyXEL Device’s Web Configurator.
Table 22 Additional Wireless Terms
TERM | DESCRIPTION |
RTS/CTS Threshold | In a wireless network which covers a large area, wireless devices |
| are sometimes not aware of each other’s presence. This may cause |
| them to send information to the AP at the same time and result in |
| information colliding and not getting through. |
| By setting this value lower than the default value, the wireless |
| devices must sometimes get permission to send information to the |
| ZyXEL Device. The lower the value, the more often the devices must |
| get permission. |
| If this value is greater than the fragmentation threshold value (see |
| below), then wireless devices never have to get permission to send |
| information to the ZyXEL Device. |
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Preamble | A preamble affects the timing in your wireless network. There are |
| two preamble modes: long and short. If a device uses a different |
| preamble mode than the ZyXEL Device does, it cannot communicate |
| with the ZyXEL Device. |
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|
Authentication | The process of verifying whether a wireless device is allowed to use |
| the wireless network. |
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|
Fragmentation | A small fragmentation threshold is recommended for busy networks, |
Threshold | while a larger threshold provides faster performance if the network |
| is not very busy. |
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