Max no. of repeaters per access point

Just wanted to know if there is any max limit of repeaters per access
point. My client was asking if he could escape using more access points
by installing wireless repeaters.

Moreover, is there any price difference between access points and
wireless repeaters, or they are more or less the same?

Thanks a lot
Gautam

On 8 Dec 2005 18:59:01 -0800, (E-Mail Removed) wrote:

>Just wanted to know if there is any max limit of repeaters per access
>point. My client was asking if he could escape using more access points
>by installing wireless repeaters.

There's no theoretical limit, but there are some problems with too
many repeaters.

1. The maximum thruput gets cut in half for every repeater hop. If
you can move perhaps 20Mbits/sec through an access point, then the
first repeater will limit the thruput to 10Mbits/sec. The 2nd will
yield 5Mbits/sec. The 3rd will yield 2.5Mbits/sec, etc. This is not
a problem with back to back radios acting as a repeater as they can
run full duplex using two different RF channels. However, these cost
twice as much.

2. Adding store and forward repeaters and "range extenders" requires
that everything run on the same RF channel with the same SSID. That
means you'll get quite a bit of interference from your own repeaters.
On a given channel, only one radio in a given airspace can transmit at
a time. If you have a "hidden transmitter" problem, then you will
have interference from your own radios.

3. In a repeater system, a lost packet along the path has to be
resent from scratch. You'll find that repeaters generate considerable
duplicated traffic.

4. Repeater protocols (including WDS) are not very well defined. They
will not work with every access point and client radio available. Most
manufacturers have a limited list of compatible hardware.

In case it's not obvious, I don't like repeaters (and mesh networks)
and think of them as little better than unintentional jammers.

Incidentally, I'm scheduled to partially rip out a system consisting
of one access point and 5 repeaters real soon and replace it with
wired access points. I was also instrumental in convincing the county
to remove their "range extender" that was repeating literally
everything it heard and creating more interference than connectivity.

>Moreover, is there any price difference between access points and
>wireless repeaters, or they are more or less the same?

I have no idea. Obviously, your client has an existing wireless
system. If you would kindly disclose the make and model of the
existing hardware, it might be possible to find a compatible repeater
or access point and attach a price tag.


--
Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
831.336.2558 voice
http://www.LearnByDestroying.com AE6KS
http://802.11junk.com Skype: JeffLiebermann
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