So is it good to AMP and if so why not?

We currently have a 532 board on a tower that has a CM9 with a 1 watt amp on it. I think this is a bad configuration. What are your feelings and experince with using AMPs. We also have a cavity filter and we are thinking of deploying it but have uncertainty associated with this. If any one else have any comments or suggestions please post them back to us. Thanks.

-Sincerely,
DesertAdmin

I inherited 5 access points with 1 watt amps. None of them stayed up more than a year. They caused all sorts of interference for me. Get a little moisture and corrsion inside and all sorts of weird S*!$ happens
I remember one problem that was driving me crazy for days. Two of my access points were acting up and customers were connecting/disconnecting. The access points were 6 miles apart from each other and both locations were sectorized V-pol. I was sure one was interfering with the other but couldn't nail down the problem.
Long story made short, the problem ended up being the amp on an access point 8 miles away from one location and 14 miles from the other.

Aug is right!

Don’t use amps!!!

If you do you WILL regret it!

Howdy,

Is there any other reasons why? I do not understand why they would make amps perhaps they are not meant for 2.4ghz wireless? Why would a company make AMPS are they only for back hauls for great distances or are they for CPE side and not APs? I want to remove the amps from our network but I want more of a leg to stand on bringing this up to the rest of the company. I do not like the AMP and I a do regret them being in place but what is one to use instead of an AMP? You can only have up to 1WATT here in the US and our cards for 2.4 that we have currently are only up to 400mW. So with our limited resources, and limited budgets and a non-affluent community we are working with what we have. Is a 400mW card sufficient enough for removing a 1WATT AMP?

Also any one use any cavity filters? These are those crazy devices that look like an AMP but have a ton of screws across it and it only listens on a given channel. Everything else on the cavity filter is filtered out. I have a feeling that a cavity filter because it kills off all other channels it does not allow the extra few channels around your channel number to work. For instance channel one aka 2412 also uses up to 2422 (or so) which is channel three bleeding over. So i think in theory a cavity filter may kill off that bleed over which may impair or congest how the channel oeprates on say channel one.

Any thoughts on this? I just am curious and want to better understand before we deploy. Thanks for everyone's response in advance.

-Sincerely,
DesertAdmin

#1 - They amplify noise almost as well as they amplify signal. Check the specs on the amp. are they designed for specific channels.

#2 - Where is the amp located? At the top with the antenna?
1 watt amp = 30dbm and 6dbi antenna = 36dbm - line loss, connectors, etc...might put you at 34dbm or allow for 8dbi antenna.
I want at least 12dbi antenna and preferably 16dbi.
What are you using for antennas?
How far is the amp from the antenna?
In other words are you exceeding max eirp?
The ones I inherited were able to be set at 100mw, 250mw, 500mw and 1 watt.
All were set to 1 watt with 12dbi omnis and 6 feet of lmr-400 btwn the amp and the antenna.
I'm thinking that was a little over 36dbm eirp for ptmp.
First thing I had to do was turn them down to 250. Still caused problems.

#3 - It's just something else to go wrong. And as in my previous post, you might play hell finding the problem.

I do not know the exact dbi of the sector we have up there my biz partner would know that better. I will definitely find out more on that. The distance is pretty small it is in a galvanized enclosure that is about 1-2 ft away from the antenna. I am sorry do you have a URL to the EIRP PTMP that you are referring to that is something I do not understand and I would like a good document to read up on this. Thanks.

-Sincerely,
DesertAdmin

eirp in U.S. is governed by FCC. Part15 mumbo jumbo equates to 36dbm for point to multi point - ptmp
google is your friend
search 2.4 ghz eirp and you'll find loads of info
here's a quick and dirty link
http://www.michwave.com/bbnetwork/faq/fcc.htm

I made a US link power / budget / EIRP calculator based off a European one to the best of my understanding of the FCC regs, keep in mind this may be wrong!

http://r-1.ch/wlan/

WOW! Thank you very much I will try to figure all of this out and we ar eplanning to remove the AMPs off of our networks. I think we currently only have like 3. Nonetheless I appreciate your posts very much. Thanks!

-Sincerely,
DesertAdmin