A brief history. http://inventors.about.com/od/wstartinventions/a/WiFi.htm
The standards continue to evolve to improve reliability and
throughput. Keep in mind it’s not just
the speed at the router, but also what your device can handle that determines
your net speed. Here is a chart that
shows how WiFi has evolved.
|
Standard
|
Year
|
Speed (Mbit/s)
|
|
802.11
|
1997
|
2
|
|
802.11a
|
1999
|
11
|
|
802.11b
|
1999
|
54
|
|
802.11n
|
2002
|
54
|
|
802.11g
|
2009
|
100
|
|
802.11ac
|
2012
|
500
|
The speeds vary with some standards, but these are a good
rule of thumb. For example 802.11ac is
marketed as 1Gbit/s, but you don’t always see that.
Speed is not the only consideration. There is also range, wall penetration, and
susceptibility to interference. Indoor
and outdoor range can vary by an order of magnitude. Walls can contain metal or other materials
that attenuate the signal. The airways
around us continue to be full of other RFI. Some standards allow for reduced
throughput to compensate for loss of signal strength.
At home we typically have a router with a WiFi
antenna. In an office or campus environment
WiFi is deployed with WiFi access points (AP) and controllers. The controller
is a device on the LAN that manages multiple WiFi access points in a hub and
spoke configuration. The controller
balances the traffic among the access points.
Since speed decreases if your device is further from the antenna, access
points are placed in a grid for better coverage and throughput (think cell
phone towers). When deploying
organization wide WiFi an assessment can be done to help determine the number
and location of access points to meet your objectives.
The demand for wireless (WLAN) bandwidth will
continue to grow as PCs, phones, tablets, WiFi devices of all sorts, and high
bandwidth applications want more and faster data. Perhaps a wireless plan is needed to keep up.