Does the mac book pro tell a WAP to power back?

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Hi All,

I have a customer with a Mac Book Pro.  On two separate Netgear
"router/hub/Wireless Access Points", after changing the wireless
channel, about five minutes later the (radio strength) power
levels drops from the max of five bars to two.  Is the Mac Book
Pro telling the router to do this?  Is there some feedback
mechanize in play to keep your signal from going down the street?

-T

The customer also has an iPad and an Android phone on the network.

Re: Does the mac book pro tell a WAP to power back?
On Friday, June 26, 2015 at 5:15:20 PM UTC-7, T wrote:
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I don't know about Netgear, but there is no mechanism with which *our* APs
will reduce our transmit power based upon what the client tells us (per se.)
So I really can't guess what's going on.  (The converse is not true, btw -
there *are* protocols by which our APs may tell clients to change their transmit
power.)

Let's say that you were to install WiFi Analyzer or similar on your Android
phone, and put the Android phone next to your Mac, and lock the Android onto
the AP of interest ("Signal Meter").  Then do your thing with the Mac.  Do
find that, at the time when the Mac reports a drop from five bars to two, the
Signal Meter RSSI also drops?

Aaron

Re: Does the mac book pro tell a WAP to power back?
On 06/29/2015 01:41 PM, aaron@cisco.com wrote:
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Hi Aaron,

The bars drop on all three devices (Mac Book Pro, Android,
iPad).  The customer has a fancy app on the android that
shows strength of everyone around you.

My first thought was a feedback mechanism like that used
on cell phones.

In the mean time I have found this in Netgear's manual:

        3. (Optional) Clear the Enable 20/40 MHz Coexistence check
           box to increase the wireless speed to the maximum supported
           speed.  By default, 20/40 MHz coexistence is enabled to
           prevent interference between wireless network in your
           environment at the expense of the wireless speed. If there
           are no other wireless networks in your environments, you
           can clear the Enable 20/40 MHz Coexistence check box.

Hmmmm.   I am thinking that reading between the lines, if the router
see a lot of other APs nearby, that it reduces its power to assist
with congestion.  And this customer has about 11 AP's showing up
from his neighbors as he lives in a crowded community.

And, both routers were Netgear.  And this is the most congestion
I have seen with a Netgear router.  (I have seen worse at an apartment
complex with another router.)

What do you think?

Thank you for helping me with this.

-T


Re: Does the mac book pro tell a WAP to power back?
On Monday, June 29, 2015 at 3:21:56 PM UTC-7, T wrote:

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I wouldn't expect this to have an effect on transmit power.

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That's conceivable.  I've not ever known any APs (unless under direction
from some central controller) to voluntarily step down their power ... but
it would be nice if they did.

Again, I'm afraid that I have no recent experience with Netgear.

Good luck,

Aaron

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