Dell Sonicwall Sonicpoint Ace, Руководство по началу работы

Страница: 10 / 53

8 |
Wireless RF
introduction
There are currently four widely adopted standards for 802.11
wireless network types: a, b, g, and n. Although 802.11n is the
newest and highest capacity standard, each of the four
standards has its own strengths and weaknesses. This section
provides overviews of these standards.
The following section provides a brief overview of RF
technologies:
•
"Frequency Bands and Channels"
on page 8
•
"802.11 comparison chart"
on page 9
•
"Radio frequency barriers"
on page 9
•
"RF interference"
on page 10
Frequency Bands and
Channels
To allow multiple separate wireless networks in a shared and
confined space, the RF medium is divided into channels. For
devices in the 5GHz range (802.11a), this means the possibility
of up to 23 discrete channels. For devices using the 2.4GHz
range (802.11b, 802.11g), the wireless space is limited to a
maximum of 14 overlapping channels. As a result of these
overlapping channels, 2.4GHz technology provides only a total
of three discrete channels.
The newer 802.11n technology does not fit into either of these
categories, as it is capable of using both 2.4GHz and 5GHz,
but is limited to 14 overlapping channels for backward
compatibility.
SonicPoint_ACe_GSG.book Page 8 Monday, September 29, 2014 5:23 PM
Draft
Document