Wireless
Networking Repeater Technology for WiFi Hotspot
One of the
limiting factors in wireless computer communications has to do
with the limited signal strength allowed in the 802.11a/b/g
wireless networking devices.
The total effective radiated
power allowed for one-to-many wireless networks in the United
States is 4-Watts maximum. In other countries throughout
the world the maximum radiated power is less - sometimes much
less.
The limitation of the maximum
radiated power limits the usefull range of a wireless access
point to something on the order of about 300-ft (100
meters).
A second limitation has to do
with the relative sensitivity to the signal by the
different devices being used in wireless networking.
A wireless access point may have a medium gain antenna
connected that effectively "boosts" the received signal by
3 to 4 times due to the antenna's gain but a wireless PDA
may only have a 1.5X gain due to it's relatively small
built-in antenna. This difference in antenna gain
means the wireless access point' signal will "reach" about
twice as far as the PDA signal. What this means in
terms of the network is the PDA will "hear" the wireless
access point's signal much further than the wireless access
point will "hear" the PDA - if you can not hear it, you can
not talk to it (tm)!
In a relatively small area,
such as a Caf'e or meeting room this is not a problem but
if you are wanting to provide a signal in a larger area
such as a resort pool area the useful signal may not be
enough to cover the area.
One method of overcoming the
distance limitation is to install a second wireless access
point configured to operate as a wireless "repeater".
The advantage of installing a wireless repeater over a
second wireless access point is the fact you do not have to
run an ethernet cable to the second wireless access point -
only power for the device is required as the "link" is
provided wirelessly from the first wireless access point to
the repeater.
Installing a wireless
repeater effectively increases the total coverage area of
the wireless network. The wireless clients can
connect to the original wireless access point or to the
wireless repeater. When the client connects to the
wireless repeater the signal from the client is "repeated"
to the wireless access point.

Advantages to using a
wireless repeater:
- Effectively increases the
coverage area
- Does not require an
ethernet connection to extend the wired network
signal
- Only requires power at
the repeater location
- Allows the client to roam
within the coverage area
There are some disadvantages
to the use of a wireless repeater as well.
Since the wireless access
point and the wireless repeater operate on the same channel
and since only one radio transmitter can send at a time the
effective data bandwidth (throughput) is cut in half for
each repeater added to the chain.
I hope you found this
information useful!
Author: Gary N.
McKinney
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