Stunned with HP2

[davekall]

I am having some issues with some HP2's. Basically I have two of them configured in ap-wds bridging mode. Not running any security. Both of the APs link up fine and have strong signal lights. Currently they are about 50 feet apart. If I get on through wireless on local AP I can ping fine to the local AP but when I ping the further AP I keep getting dropped packets and I can't even access the GUI at times. I tired doing an install at a client yesterday and had terrible results when I tried to access the internet through the remote AP. Infact most of the time I would lose internet all together even though I could get an IP from the router on the local side. This can't be how these APs function?? :? I have seen a few other posting on these forums with the same issues and no answers? Any help would be VERY appreciated! We are really hoping to be able to use ubiquity products in future installs but not if we can go to best buy and get a linksys and have much better performance.

Thanks! :)
Dave

[WHT]

Try turning down the power on both radios to about 10 dBm and try again.

[davekall]

Ok, I turned the power down on the radios. One radio was ok, but the other lost almost all its power and I could not even see it from the other room?
What am I missing here? Why would you want to turn the power down on the radios? I thought that was the whole point to having 1000mW?

[WHT]

The goal is to provide sufficient power to the for whatever data speed you are using, but delivering more than -30 dB will overload the receiver front end at a short distance. As I once posted:

http://ubnt.com/forum/viewtopic.php?p=25938

If you have identical gain antennas, then you would want the same power settings at both end.

[davekall]

Thanks for the information. That does make sense. So with HP2s say at 200ft apart what dbm setting would you want? What if you have 3 HP2s at different differences apart what would you do then? I am starting to get the idea that HP2s are overpowered for a large home install and they are over powering each other?

[WHT]

Bullet 2 HP radios are not the best product for you application, the Picostation HP 2 radios would have been better.

But since you already have the Bullet HP radios (what antennas are you using? what is the antenna gain?), I'd put them in place and adjust your power accordingly such that no radio gets more than a -30 dBm signal.

As high as -40 and down to as little as -60 would be optimum.

[davekall]

Actually the Pico HP2's are what I am using. If I look at the output power it only goes to -30dbm to -10dbm. I had them set at -30dbm before when I was having the issues. I will have to look but they may have not been set at the exact same dbm though. One might have been at -27 and the other at -30. I can see I have a lot to learn about wireless. :roll:

[davekall]

I got it now. Its the -dbm signal that is displayed in netstumbler that we are talking about. Basically I just need to adjust the power in the HP2's so that it is within the range of -40dbm to -60dbm at the remote AP and preferably at -30dbm. The output dbm has to be identical in all of them though, right?

[davekall]

Ok, I have now tried with two Pico HP2s to put them both at 10 and 20 dbm. I am still getting signal loss on the remote AP when I connected to the local AP. It does not seem to change no matter what I set the output power at. Is there something else I should look at?

Thanks! :)
Dave

[WHT]

Netstumbler doesn't really show you true signal level, rather an aggregate of noise and signal.

Go here:
http://www.ubnt.com/support/freespace.php

Use .1 (one tenth of a mile of 528 ft) a starting point for you transmitter output power (TPO) level. That would be an 84 dB loss. Now halve the distance and you reduce your loss by 6 dB, so the effective loss for 264 feet is 78 dB.

If the Pico is set for 30 dBm TPO, at 264 the signal would be -48 dBm. Now add 6 dB at both ends for your antenna gains and you get -36 dBm and that would be close to overloading the receiver front end. Halve the distance again for 132 feet and you be at -30 dBm and that is likely going to overload the front end. Halve it yet again for 66 feet and you get -24
dBm and that will be overlapping the front end.

This is assuming a best case signal path with no intervening walls.

[davekall]

Ok, that makes sense if it is set at 30 TPO. I did take it down to 10 dbm TPO with still the same problem at about 50 feet. The calculator that you put a link to doesn't go below .1 mile. The problem I am seeing is that when I take it down to 10 the signal all but disappears even if I am right next to it. 10 dbm is 10mW correct? If I were to put the APs at that TPO they would not be very effective as an AP if I am not mistaken? Most retail APs are are around 60mW or so and have a radius of around 200ft or so.
Is there another program you recommend other than netstumbler?

[WHT]

The calculator that you put a link to doesn't go below .1 mile.You have to calculate it yourself. Every time you double or halve your distance, you subtract or add 6 dB.
Is there another program you recommend other than netstumbler?NS is mainly a "Search & Find" tool, for actual signal levels I'd use the radio's built in signal level meter function.
Most retail APs are are around 60mW or so and have a radius of around 200ft or so.Under optimum conditions. Wireless newsgroups are flooded with people that can't get their consumer grade products (50 to 100 mW) to cover a 2,400 square foot house.

[davekall]

Don't get me wrong, consumer grade wireless isn't good at all. But I am not sure how a 10mW AP is going to do me any good. We started buying the HP2s because of how much scalability there is in bandwidth. I find it hard to believe that if I were running an AP at 100 or even 200 mW that I would be overpowering the other AP. I can't see the benefit to that. There must be something else going on with my APs.

[WHT]

I find it hard to believe that if I were running an AP at 100 or even 200 mW that I would be overpowering the other AP. It doesn't matter how much power and antenna gain you have, if you're putting more than -30 into the receiver's front end, you will start to see degradation.

I can't see the benefit to that. When was the last time you saw a consumer device for home use with a 12 dBi antenna? they have low gain antennas that work better for short range.

There must be something else going on with my APs.I would do some simple testing. One radio in AP mode to another radio in Station mode. Place both radios in the locations you will be using them.