Page 1 of 1

Eratic Behaviour of wireless

Posted: Tue Jan 31, 2006 1:04 pm
by nowoxi
hello i dont know if i should call myself a newbie with wireless but i have being at it for a couple of months, but i have had 1 major problem i use a 1w amp and it seems to stop working every 3 weeks for no good reason it just doesnt power up again, and i have all sorts of surge protectors.

Anyway i replaced it for a third time still trying to figure out why. i guesed it that was heat that stops it becasue its quite hot around here so i installed a coolant system. the amp is on my mast. but the last time i replaced it i notice something. the wireless raNGE SEEMED to have just cut back it doesnt seem to get to where it used to get anymore. and the weird thing is that the signal strength in the MikroTik is alot better than it used to be, i used to work with about -88db before but its risen to about -71.but at the client points the signal says low at the points it used to be excellent. so its like the signal has gotten better at the base station worse at the client points. please can anyone help me with that.what coul dbe happening, what do i have to check or do

Posted: Tue Jan 31, 2006 1:39 pm
by djape
Unless you bought some high quality booster my advice is to get rid off it!
Try it and you'll be surprised that quality of you Internet is going to improve.
So many times I was writing about boosters. They'll give power but also a lot of noise and sensitivity of the card will become very bad.
So, with 1w booster you'll have -70 and bad performance and without you'll have -80 but performance will be great.
Boosters can't give you a coverage, they'll just boost signals that you would also have without them.
Furthermore, user that connects from long distance will have better performance without booster.

Take a deep breath and try this ;)


Posted: Tue Jan 31, 2006 8:42 pm
by nowoxi
thanks alot for your reply

so like now if i remove my amp i will have a borad 500 series, an athreos 200mw and a 15db omni antenna. how far do you think that can go at your place?

Now in my place before the AMPS STARTED GOING BAD i could go 1km away with a centrino laptop and it will still connect fine. now at the present state which is pretty bad i can go 500m and no problem and 1km in some particular directions and the weirdest of them all at some particular time of the day. Do you think i can still make any of this performance that i have at the moment? will it be more or less?
because i wouldnot mind removing it if its a solution and it will stil cover the range. and removing the amp does it not mean my network will be suseptible to more interfernce?

Posted: Tue Jan 31, 2006 11:29 pm
by ucheonyeaka

Please try as much as possible never to use Amps. Disconnect the Amp and you will be suprised at the result you will get.

If you still want to increase your area of coverage try the SR2 cards instead of using Amp.

Good Luck!


Posted: Wed Feb 01, 2006 6:42 pm
by nowoxi
I would like to chat with you and if possible meet since we are both from Nigeria. I woul dlove it if we could arrange soemthign my email is nowoxi at and my num is 7000 775 on mtn network. what do u say?

Posted: Wed Feb 01, 2006 8:25 pm
by nickb
so like now if i remove my amp i will have a borad 500 series, an athreos 200mw and a 15db omni antenna. how far do you think that can go at your place?
That could be your problem right there! Most amplifiers have a maximum input power of 100mW -- you could have been burning them out.

I would suggest reducing your output power to something on the order of 60-80mW if you're going to continue using the amplifier. We have used 1W amplifiers extensively in the past with Orinoco AP1000 equipment because of it's low native power. We get great coverage and usability with them.

But! We are also pretty happy so far with the coverage and usability of the SR2 400mW card from Ubiquity - aside from the power issues.

So, I have no hard evidence either way, but I can say that I have had good experiance on a system without an amplifier at 400mW.

Posted: Wed Feb 01, 2006 9:24 pm
by djape
@nowoxi and ucheonyeaka

I was two years in Nigeria, Abuja, now WAO :D

Listen, if you placed amps for connecting with laptop from 1km distance then I don't know what to say except that 802.11b is just not technology that's gonna do work for you.


Posted: Thu Feb 02, 2006 12:56 am
by sten
so like now if i remove my amp i will have a borad 500 series, an athreos 200mw and a 15db omni antenna. how far do you think that can go at your place?
Try shortening your cables to within 30 cm's. Less is more.
If it's 802.11g then don't try to get 54/48mbit everywhere. 54mbit and 48mbit are too sensitive to noise, set an upper limit like 24mbit and your error rate will be much lower and your retransmissions fewer.
Set the ack-timeout to a fixed value. Use either long or short preamble, not both. Increase failure retry time to say 200ms. See if enabling periodic calibration helps (it can sometimes take some time).

An amplifier boosts the signal, but it also boosts any interferrence. An amplifier will in virtually all cases add interference or in other ways increase error rate. When error rate or retransmissions go up you dramatically reduce performance. Sometimes an amplifier will boost the signal too much and damage the radio.

If you instead tune the many parameters you might find that you can go pretty far without amplifier. What you previously thought was a bad signal will no longer give you bad performance.

Posted: Fri Feb 03, 2006 2:19 pm
by nowoxi
it was the amplifier itself that always got damaged so if the amp is over powering something i believe it shouldnt be the 1 dieing out. what do u think