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Maximum power level assignment Vs TX power levels

Hi,

I want to know if I change maximum power level assignment, how it's gonna affect the TX power levels?

For example if the maximum power level assignment set to 11 dbm, TX power level 1 is gonna be 11dbm. isn't it?

BR,

Majid

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Cisco Employee

TX power level 1 is always

TX power level 1 is always maximum power level of access point.

The transmit power level is assigned an integer value instead of a value in mW or dBm. The integer corresponds to a power level that varies depending on the regulatory domain in which the access points are deployed. The number of available power levels varies based on the access point model. However, power level 1 is always the maximum power level allowed per country code setting, with each successive power level representing 50% of the previous power level. For example, 1 = maximum power level in a particular regulatory domain, 2 = 50% power, 3 = 25% power, 4 = 12.5% power, and so on.

In certain cases, Cisco access points support only 7 power levels for certain channels, so that the Cisco Wireless Controller considers the 7th and 8th power levels as the same. If the 8th power level is configured on those channels, the configuration would fail since the controller considers the 7th power level as the lowest acceptable valid power level. These power values are derived based on the regulatory compliance limits and minimum hardware limitation which varies across different Cisco access points. For example, Cisco 3500, 1140, and 1250 series access points allow the configuration of last power levels because those access points report the "per path power" to the controller, whereas all next generation acess points such as Cisco 3700, 3600, 2600, and 1600 series access points report "total power value" to the controller, thereby decreasing the allowed power levels for newer generation products. For example, if the last power level in the 3600E access point has a power value of 4dbm (total power), then it actually means the power value is -2dbm (per path).

Note   

See the hardware installation guide for your access point for the maximum transmit power levels supported per regulatory domain. Also, see data sheet for your access point for the number of power levels supported.

10 REPLIES
Hall of Fame Guru

TX power level 1 is gonna be

TX power level 1 is gonna be 11dbm.

Depends on the AP (it's printed on the Data Sheet of the AP).  11 dBm is usually a "5" or mid-level.

Hi Leo,

Hi Leo,

I think I couldn't explain my question very well.

Suppose your AP is AIR-CAP2702-E and you change the maximum power level assignment in the WLC settings to 11 dbm, I want to know after that, TX power level 1 is gonna be 11dbm for the APs?

Thanks In advance.

BR,

Hall of Fame Guru

If you want 11 dBm then

If you want 11 dBm then manually put the power setting to "5".  If you want the AP to operate at power level "1" then the power will be 23 dBm.

I don't think it's possible to set the power level to "1" and expect the AP to operate at 11 dBm.

Leo,

Leo,

There is an option in TPC setting of WLC that you can set maximum power level assignment.

I think if you set this value to 11 dbm for example, then the maximum power that an AP can transmit to the AP " TX power level 1" is gonna be 11dbm.

If I didn't understand it very well, I would be very appreciate to explain it for me.

BR,

Majid.

Rising star

The value of the power levels

The value of the power levels depends on the access-point (type, regulatory domain, channel in case of 5Ghz and the configured gain on the individual radios in case of external antennas). Based on the configuration you are referring to RRM will assign certain power levels, not adjust the values.

Please rate useful posts... :-)

Just to add...

Just to add...

That TPC MIN-MAX is a way of tuning RRM. It allows you to say don't exceed X or go lower then Y. Its a great tool to use to tune RRM.

"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
___________________________________________________________
Cisco Employee

TX power level 1 is always

TX power level 1 is always maximum power level of access point.

The transmit power level is assigned an integer value instead of a value in mW or dBm. The integer corresponds to a power level that varies depending on the regulatory domain in which the access points are deployed. The number of available power levels varies based on the access point model. However, power level 1 is always the maximum power level allowed per country code setting, with each successive power level representing 50% of the previous power level. For example, 1 = maximum power level in a particular regulatory domain, 2 = 50% power, 3 = 25% power, 4 = 12.5% power, and so on.

In certain cases, Cisco access points support only 7 power levels for certain channels, so that the Cisco Wireless Controller considers the 7th and 8th power levels as the same. If the 8th power level is configured on those channels, the configuration would fail since the controller considers the 7th power level as the lowest acceptable valid power level. These power values are derived based on the regulatory compliance limits and minimum hardware limitation which varies across different Cisco access points. For example, Cisco 3500, 1140, and 1250 series access points allow the configuration of last power levels because those access points report the "per path power" to the controller, whereas all next generation acess points such as Cisco 3700, 3600, 2600, and 1600 series access points report "total power value" to the controller, thereby decreasing the allowed power levels for newer generation products. For example, if the last power level in the 3600E access point has a power value of 4dbm (total power), then it actually means the power value is -2dbm (per path).

Note   

See the hardware installation guide for your access point for the maximum transmit power levels supported per regulatory domain. Also, see data sheet for your access point for the number of power levels supported.

Beginner

It varies by AP model as well

It varies by AP model as well as by frequency (2.4 GHz vs 5 GHz). A 2702 has seven power levels in each frequency:

2.4 GHz

5 GHz

22 dBm (1)

23 dBm (1)

19 dBm (2)

20 dBm (2)

16 dBm (3)

17 dBm (3)

13 dBm (4)

14 dBm (4)

10 dBm (5)

11 dBm (5)

7 dBm (6)

8 dBm (6)

4 dBm (7)

5 dBm (7)

If you set the maximum power level to 11 dBm, the access point will only use power levels 5, 6, and 7. It does not set power level 1 to 11 dBm.
Beginner

Re: It varies by AP model as well

Sorry to reopen this old thread, but how does the antanna gain combines with it? Is the "Maximum Power Level Assignment"set in the WLC EIRP?

Max power set to 11dBm, antanna gain for 5GHz is 4dBi (rubber duck) -> power level will be set to 7 (5dBm+4dBi=9dBm)?

Enthusiast

Re: It varies by AP model as well

Hi just noted someone asked a question on this older post.

 

I actually wrote a blog entry on this stuff if it helps...

 

https://nc-expert.com/tips-tricks/wlc-ap-power-settings/

 

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