ZyXEL Communications NVG2053, Руководство пользователя

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Chapter 8 Wireless LAN
NVG2053 User’s Guide
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devices exchange information with one another. A wireless networking device is
just like a radio that lets your computer exchange information with radios
attached to other computers. Like walkie-talkies, most wireless networking
devices operate at radio frequency bands that are open to the public and do not
require a license to use. However, wireless networking is different from that of
most traditional radio communications in that there a number of wireless
networking standards available with different methods of data encryption.
Wireless Network Construction
Wireless networks consist of wireless clients, access points and bridges.
• A wireless client is a radio connected to a user’s computer.
• An access point is a radio with a wired connection to a network, which can
connect with numerous wireless clients and let them access the network.
• A bridge is a radio that relays communications between access points and
wireless clients, extending a network’s range.
Traditionally, a wireless network operates in one of two ways.
• An “infrastructure” type of network has one or more access points and one or
more wireless clients. The wireless clients connect to the access points.
• An “ad-hoc” type of network is one in which there is no access point. Wireless
clients connect to one another in order to exchange information.
Network Names
Each network must have a name, referred to as the SSID - “Service Set
IDentifier”. The “service set” is the network, so the “service set identifier” is the
network’s name. This helps you identify your wireless network when wireless
networks’ coverage areas overlap and you have a variety of networks to choose
from.
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.