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northbanker
Posts: 142
Registered: ‎03-05-2012

Does Transmission Power do anything? (on EA4500 or E4200v2?)

I just did a test of an EA4500 by going into the hidden Wireless_Advanced settings page, and lowering the Transmission Power from High to Medium then Low.

 

I rebooted after each change and I tracked the signal strength with InSSIDer on my laptop.

 

You know what I never saw any difference!   The signal was really strong, e.g. -45dB in the room below my WAP, regardless of what power setting I chose.

 

This is REALLY disappointing results for my test.  I was really banking on lowering the power on one WAP at a customer site where they have several WAP's on different networks but in pretty close proximity.

 

Has anyone else ever done any testing of the power settings on either EA4500 or E4200v2 and had similar or different results than mine?

hillary681
Posts: 800
Registered: ‎04-22-2012

Re: Does Transmission Power do anything? (on EA4500 or E4200v2?)

no tests done on my end.

hope they can look into this feature as it will really help with resolving wireless dropout issues.

northbanker
Posts: 142
Registered: ‎03-05-2012

Re: Does Transmission Power do anything? (on EA4500 or E4200v2?)

Anyone else?  Ever tested if lowering power level in adv.settings actually does anything??

Expert
zee29
Posts: 1,329
Registered: ‎04-22-2012

Re: Does Transmission Power do anything? (on EA4500 or E4200v2?)

So no increase in the speed whatsoever? Wow. Didn't even know about the hidden link in the router page. :smileyindifferent:

northbanker
Posts: 142
Registered: ‎03-05-2012

Re: Does Transmission Power do anything? (on EA4500 or E4200v2?)

I wasn't looking for more speed. I'm looking for less transmit power, thus less interference with other neaby wireless access points.

 

I'd really LOVE to know if anyone else has or could do a transmit power test and if they have similar (shocking?) results.



Expert
Expert
Posts: 12,649
Registered: ‎07-16-2006

Re: Does Transmission Power do anything? (on EA4500 or E4200v2?)

All new 802.11n routers do power management and adjust transmit power automatically. If the setting does anything then adjust the maximum allowed transmit power. But you will see that change only if it has to go to the maximum transmit power, i.e. at the edge of the covered area. Or in other words, less maximum transmit power should reduce range. You would see a difference only in some distance. Close by the router will remain below the maximum anyway and thus you won't see a difference.
frboyer
Posts: 11
Registered: ‎06-01-2012

Re: Does Transmission Power do anything? (on EA4500 or E4200v2?)

I also have these results with the EA4500; changing the "Transmission Power" does not change the power reading on my laptop.  Even at "low", the power is much higher (around 20dBm higher according to inSSIDer reading) for "outdoor" channels, than at "high" for "indoor only" channels (channels 36 to 48); that is for the Americas (see maximum power levels).  That reading is weird, as the difference between 160mW and 800mW should be 7dBm, not 20, but it seems to show that you cannot reduce the power of other channels to the "indoor" levels using the "low" setting.  So I do not understand what the "transmission power" setting does, if it works.

 

Note that if you are in America, you can reduce power if all your devices can use the 5GHz band, by configuring them to use a channel in the 36 to 48 range.

northbanker
Posts: 142
Registered: ‎03-05-2012

Re: Does Transmission Power do anything? (on EA4500 or E4200v2?)


frboyer wrote:

I also have these results with the EA4500; changing the "Transmission Power" does not change the power reading on my laptop.  Even at "low", the power is much higher (around 20dBm higher according to inSSIDer reading) for "outdoor" channels, than at "high" for "indoor only" channels (channels 36 to 48); that is for the Americas (see maximum power levels).  That reading is weird, as the difference between 160mW and 800mW should be 7dBm, not 20, but it seems to show that you cannot reduce the power of other channels to the "indoor" levels using the "low" setting.  So I do not understand what the "transmission power" setting does, if it works.

 

Note that if you are in America, you can reduce power if all your devices can use the 5GHz band, by configuring them to use a channel in the 36 to 48 range.



Thanks for testing and corroborating my results.  I'm REALLY disappointed if there is no way to lower the power output from the router.  Hmm.

Jake_2.0
Posts: 2,157
Registered: ‎05-29-2012

Re: Does Transmission Power do anything? (on EA4500 or E4200v2?)

This is interesting! Would it be ok that you will show me the link for transmission power so that I may replicate this using my friends router. Thanks!

hiptechboy
Posts: 1,557
Registered: ‎01-03-2011

Re: Does Transmission Power do anything? (on EA4500 or E4200v2?)

[ Edited ]

Jake_2.0 wrote:

This is interesting! Would it be ok that you will show me the link for transmission power so that I may replicate this using my friends router. Thanks!


Change the IP adress if it isn't 192.168.1.1 : http://192.168.1.1/Wireless_Advanced.asp

I don't work for Cisco. I'm just here to help.