What You Need To Know; Wireless Basics; Wireless Security - ZyXEL Communications P870HNU-51B User Manual

Chapter 7 Wireless LAN

7.2 What You Need to Know

Wireless Basics

"Wireless" is essentially radio communication. In the same way that walkie-talkie radios send and
receive information over the airwaves, wireless networking 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.

Wireless Security

By their nature, radio communications are simple to intercept. For wireless data networks, this
means that anyone within range of a wireless network without security can not only read the data
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P-870HNU-51b User's Guide