Posted: Mon Jul 10, 2006 20:23 Post subject: Re: 2mw xmit power better than 33mw - weird results
The very weird thing,is that I get a better signal to noise ratio at 2 mw than at 33mw.
Distance from 54GS to AP is about 12 meters, and there is a couple of walls between.
I bet the walls either have steel reinforcements (most likely) or some major electricity/gas or heating mains run right through the max. E-field of your antennas. We had a similar situation when installing data transmission in the container terminal of Hamburg Harbour: The link quality was so appaling that we increased the power to get an even worse S/N-ratio. Extrapolating our data lead us to reduce the transmission power in order to get a higher S/N-ratio.
The trick is to use line of sight communications. If you have got multiple reflections reduce you output power as much as possible.
In my testing, with one sheetrock wall between the AP and my laptop, raising power over 100mw actually lowers connection speed.
At 28mw, I get 54-48mb, at 50mw its steady 54mb. At 251mw, its 24-36mb, without moving the laptop.
Outdoors, raising the transmit power doesn't cause the same problems, and 50mw vs 200mw doesn't hurt the connection at all once you hit about 18mb, about -85dB, it improves it.
Use as low a power setting as gives you stable signal, it has been proven numerous times that raising the transmit power also raises the noise level. These are not super quality transmitters, they're not designed for this, and we're running them out of spec.
Same thing as overrevving a car or overclocking a CPU. Some handle it quite well, others don't, and there are tradeoffs with everything. _________________ mmm... forbidden donut....
Joined: 06 Jun 2006 Posts: 6978 Location: Dresden, Germany
Posted: Tue Jul 11, 2006 4:34 Post subject:
yes and no. a higher power level can increase the stability. but not at too close distances since you have effects like reflections and distortions. my comparisation to this behaviour is always screaming in the ear of someone other. sure the signal is powerfull, but you could not really listen. additionally both sides must hear each other in a good quality or better the same. not just one. if you have a long distance connection, you can test power level adjustments much better _________________ "So you tried to use the computer and it started smoking? Sounds like a Mac to me.." - Louis Rossmann https://www.youtube.com/watch?v=eL_5YDRWqGE&t=60s