tx power levels

Unanswered Question
Nov 27th, 2007
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it was kinda surprising to learn that WLC expresses tx power as 1,2,3,4,5,6.


anyone knows what is the equivalent of these levels in dBm?


the autonomous 1230 has the tx power levels as max, 100, 50, 30, 20, 10, 5


is the comparison below correct?


wlc <--> 1200

1 <--> max

2 <--> 100

3 <--> 50

4 <--> 30

5 <--> 20

6 <--> 10

7 <--> 5


what is the exact value of the 'max' level?


thanks!



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Richard Atkin Tue, 11/27/2007 - 16:10
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You've got the right idea with 1 being highest, and power decresing along the way. There's about 3dB difference between each integer, however the actual dB value varies for each setup.


The reason they're not fixed is because the WLC considers the region the network is in (EIRP laws) and antenna gain.


So,

Power Setting 1 = max power (Considering local laws and antenna gain)

Power Setting 2 = Power Setting 1 minus 3dB

Power Setting 3 = Power Setting 1 minus 6dB

Power Setting 4 = Power Setting 1 minus 9dB

and so on...

kfarrington Tue, 06/24/2008 - 07:20
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Good Question. I have fallen foul of this.


So with the following


Controller Radio Output Power

Tx Power Settings 802.11b/g (dBm) 802.11a (dBm)

1 (maximum) 17 17

2 14 14

3 11 11

4 8 8

5 5 5

6 2 2

7 -1 -1

8 - -


I have a couple of question:

How many milliwats is this does this equate to?


Is it 50, 25, 12, 6, 3, 1.5, 0.75 ?

Just used this tool but want to make sure this is correct?



http://www.aubraux.com/design/dbm-to-milli-watts-calculator.php



Also, what is power level 8? I dont have this on my controller?


Many thx,


Ken


Scott Fella Tue, 06/24/2008 - 10:04
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You can use the tool, just make sure what the db is first. 2.4GHz is 20dbi which is 100mW, 5GHz UNI-II and UNI-III is 17dbi which is around 25mw. UNI-I is 11dbi max which is 12.5mW.


So when youare at the max dbi and mw, every drop is half like mentioned above.

Scott Fella Tue, 06/24/2008 - 17:19
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That is for US (-A). You see under B, the table shows 20dbi. Under G the table shows 17dbi. Figure 5-2 & 5-3 under -A you should be looking at if you are in the US.

kfarrington Tue, 06/24/2008 - 23:27
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Thx for the clarificaion mate.


We are in E band (us limey's) cheers :)


Thx

Ken

kfarrington Tue, 06/24/2008 - 23:27
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Thx for the clarificaion mate.


We are in E band (us limey's) cheers :)


Thx

Ken

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