Radio Settings - Transmit Power

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Hello,

I need change the Transmit Power configuration in the 2,4 ghz radio only in 1 AP of all wireless domain
Actuality the transmit power profile configured is in SMART (0 to -20 dbm)... i want change static mode in one only ap maybe in -25 dbm... my questions is: if i change it don ́t affect the signal of others AP?
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Daniel Valera

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Posted 2 years ago

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Don

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You can change the power level by selecting the AP from the parent controller and configuring the power per radio. As far as signal goes; depending on the power setting, you could get channel overlap or the power of that particular AP may interfere with connecting to any existing APs in the same area as the result of being overly powered. I never recommend -25dBm due to the strain it puts on the broadcast module and that it will definitely shorten the life span of the AP.
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Daniel Valera

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Thanks.... clarify my question

Regards
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Colin Steadman

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I'm interested in your comment about putting stain on the broadcast module if its set to -25dbm. What causes the shorter life? Could you elaborate? Thanks.
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Ronald Dvorak, Embassador

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Not a problem in ROW region as we could never go that high :-(
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Don

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The transmitter has an optimal setting and I have had to use the -24dBm in an environment before. Think of it as if the transmitter is like a CPU. The more power (overclocking) you force the CPU to perform under, the shorter the lifespan. Transmitters are much the same way. They have an optimal minimum/maximum recommendation. This is for optimal ranges and longevity. So the more power you push to the transmitter, the shorter its lifespan.

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Colin Steadman

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Thanks for the insight Don, very useful. Just one last thing for clarity, I noticed both yourself and Daniel have a negative symbol in front of the values dBm values. When I look at the basic radio settings on an AP that symbol is missing - is -24dBm and 24 dBm equivalent in this case?
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Don

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Yes. We sometimes express signal with the "-" sign, but they are both the same.
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Doug Hyde, Technical Support Manager

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Typically the general rule of thumb is to not set your AP tx power greater than what the tx power is of your clients.  
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Colin Steadman

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Hi Doug, how do you generally go about determining what that value is? Is there a report showing what client Tx power is? And would I select the client with the highest value and use that?
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Doug Hyde, Technical Support Manager

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Usually, the manufacturer will supply that in tech specs of the devices you are using, some you may have to hunt around for on the internet.  
32 mW or 15dBm is what most laptops are doing, 13dBm is common for tablets, and around 11dBm for Smartphones. Our Balanced power setting on the ap's (found in AP properties) will deploy 13dBm on the radios for you by default.
(Edited)
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Sai Prasad Rao Rapolu

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Good Explanation

So when you say 15dbm for laptops , what if 8dbm is the max ?

What kind of issues we might observe !
(Edited)
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Gareth Mitchell, Extreme Escalation Support Engineer

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Mismatched power settings, where the client can hear the AP well but the AP doesn't hear the client as well, typically modern AP's have such good receive sensitivity it's less likely to be an issue.  Most likely result is a high rate of re-transmissions which if at a sufficiently high rate, would cause a loss of performance.