Hardware Reference
In-Depth Information
Most wireless networking devices you buy today are backward-compatible with the earlier
standards. For example, if you buy an 802.11n router, a computer that has an 802.11b
wireless adapter installed in it will be able to communicate with that router. However, the
speed of the connection will be limited to the fastest speed the two devices can negotiate in
common (11 Mbps, or possibly less, depending on environmental factors such as the distance
between the two devices and any interference like walls or competition for bandwidth from
cordless phones and other devices).
Although wireless is ideal for creating networks without the expense and complication
of cabling, not every environment is ideal for it. You may fi nd that wireless behaves poorly
in the following environments:
In metal-framed (and -covered) industrial units
Where concrete is used for walls and fl oors. This will absorb the wireless signal (as
well as other forms of radiation).
If there is a large, active power supply in close proximity to the wireless network, such
as a power generator or switch room.
If your home wireless system is close to a microwave oven when it's operating.
When electrical storms are in the area.
Wi-Fi Hardware
A wireless network uses hardware similar to that in a wired one. You must have a
wireless network adapter in each computer that will connect to the network, and you must
have a switch or router to join the computers into a cohesive network.
Wireless switches or routers look similar to wired ones, but they have antennas.
A wireless switch is called a
wireless access point (WAP).
Just like a wired switch, a WAP
provides a central switching station for data to be sent and received between the devices on
the network. Routers are still called routers and perform the same functions they do on a
wired network.
The acronym WAP also has another meaning:
Wireless Application
Protocol
. This is a standard for web applications, used mainly by small
mobile devices such as cell phones.
When you're setting up a wireless network, it's important to fi nd a good location for
the router or WAP. A central location is best to ensure that its signal can reach as much
of the home or offi ce as possible. For example, if there are three fl oors in the house, place
the router on the second fl oor. You may need to move it around if you fi nd that locations
where you want to use the Internet are inaccessible.
