TPC Power Transalations

[nshoe18]

With the newest version of code on the controller, I have seem to lost the power translation levels for the Transmit Power. We typically try to set the APs on controllers we deal to go no lower than 50%, Power Level 4. On the old 6.x version of code this was typically 11 for Minimum Power Level Assignment. Now it has to be between -126 and 126. Does anyone know which power level would equate to 50%?

I guess I could just figure out what 50% is of the -126 and 126, correct?

[Stephen Rodriguez]

IIRC, this is for setting the maximum and minimum power for RRM.  What you would want to do is convert the dBm 20,17,14 etc to the actual mW value.

20dBm = 100mW

17dBm = 50mW

14dBm = 25mW

11dBm = 12.5mW

8dBm =  6mW

5dBm =  3mW

2dBm = 1.5mW

-1dBm =  0.8mW

So, what you would want to set in those fields is the appropriate dBm/mW values.

HTH,

Steve

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[nshoe18]

ok so I will be setting the controller to be 12mW since it will not accept 12.5, correct? That looks like the number I want.

[Stephen Rodriguez · Accepted solution]

Correct.  Sorry, I should have mentioned it wants a whole interger value.

[George Stefanick · Accepted solution]

Keep in mind on UNII2, UNII2E and UNII3 the out put is different depending on the channel..

UNII 1                                                 UNII 2 / 3

1 = 11 dBm / 12.5 mW                          1 = 17 dBm / 50mW
2 = 8 dBm / 6.25 mW                            2 = 14 dBm / 25 mW
3 = 5 dBm / 3 mW                                3 = 11 dBm / 12.5 mW
4 = 2 dBm / 1.5 mW                              4 = 8 dBm / 6.25 dBm

[ctcahoe]

That's a very good point George. I overlooked that in our network and I'm phasing out the UNII 1 band on our APs. We can live without those four channels to increase our 5GHz range.

[George Stefanick]

Yea, its those fine detals you know ...

I blogged about it here

http://www.my80211.com/cisco-wlc-labs/2009/10/30/what-you-need-to-know-about-tx-power-and-80211a-5ghz-on-a-ci.html