Wireless Access

Hi,

What effect does "regulatory domain " has on the total transmission power or EIRP value?

If EIRP is calculated accordingly to the selected regulatory domain, then why it isn't automatically selected and why there is a manual entry for that where we can actually change it? If we can manually change it then how it is caculated auto based on the country code?

Whether i select say, UK or any other country code, "Transmit EIRP" (Configuration > AP Group >RF Management > 802.11g radio) remains same. Can't understand why :(

Please response.

EIRP stands for Effective Isotropic Radiated Power

This is a commonly used term in RF engineering circles to describe the amount of RF Power that is emitted to the air.

In general, it is a combination of a Device's Transmit Power (Tx) + Antenna Gain (Gx).

'

The monitoring page will show the MaxEIRP possible for that specific access point in your regulatory domain, as well as what is being output at the time. The 127 setting represents the literal maximum for whatever access point is connected and it will be different depending on the capability of that access point and what we are allowed output those channels in your regulatory domain. In that access point you are looking at, it is 23.5. The ARM settings do represent a range of what can be output, but the monitoring page shows what is ACTUALLY output...

BTW, 20dBm is 100mW, which is usually the indoor regulatory limit for the United States in the 2.4GHz band. The 22.5 you see there is a representation of the total EIRP, which would be 20dBm radio power plus the antenna gain.

Keep in mind that especially in the 5GHz band, some channels can operate at higher powers than other channels, so you may see differences in total EIRP depending on ARM channel selection.

On later versions of code (I am not sure from which version) you can run the following command from the CLI to show maximum allowed EIRP values for each channel:

show ap allowed-max-EIRP ap-name <AP> country-code <country>

e.g.

#show ap allowed-max-EIRP ap-name <NAME_OMITTED> country-code GB

Max EIRP setting for Country Code GB Country United Kingdom and AP type AP-105
------------------------------------------------------------------------------
Channel 1 2 3 4 5 6 7 8 9 10 11 12 13 14 36 40 44 48 52 56 60 64 100 104 108 112 116 120 124 128 132 136 140 149 153 157 161 165
------- - - - - - - - - - -- -- -- -- -- -- -- -- -- -- -- -- -- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
b              19 19 19 19 19 19 19 19 19 19 19 19 19 * * * * * * * * * * * * * * * * * * * * * * * * *
g/a          19 19 19 19 19 19 19 19 19 19 19 19 19 * 22 22 22 22 22 22 22 22 22 22 22 23 23 23 23 23 23 23 23 * * * * *
HT 20     19 19 19 19 19 19 19 19 19 19 19 19 19 * 22 22 22 21 21 21 21 21 23 23 23 23 24 24 24 24 24 24 24 * * * * *
HT 40     19 19 19 19 19 19 19 19 19 19 19 19 19 * 21 21 21 21 21 21 21 20 24 24 24 24 24 24 24 24 24 24 24 * * * * *