The power has been set to comply with regulatory agencies. We discourage people from altering the power and the antenna in order to comply with various regulatory agencies.

-adam

Hello,

In previous BSP2.3-2, WiFi txpower could be set with iwconfig command, and for example we set (decrease) it to 19mW.
iwconfig wlan0 txpower 19mW

And iwconfig wlan0 command return current txpower settings.

In the new BSP iwconfig doesn't support changing txpower
Error for wireless request "Set Tx Power" (8B26) :
SET failed on device wlan0 ; Invalid argument.

I tried with iw command
iw dev wlan0 set txpower fixed 13mBm

Although it doesn't return any error, it seems to me that, by checking RSSI level on PC, txpower is not reduced.
Also I don't know how to check current Txpower settings, there is no some iw get txpower command.

How we can reduce WiFi txpower and check current txpower settings on the new BSP2.4-4?

Regards,
Dragan

I am not sure it's possible any more with some of the driver changes, but I will ask the developer who backported the TI drivers to our BSP and get back to you.

adam

I did some reading into this and the power levels are set by a combination of the regulatory database and the NVS file which have been tuned for FCC and IC (US and Canada).

Are you looking to lower the transmit power in the 2.4 or 5 GHZ range?

Looking at the output power, it appears as if the 5170-5250 band is limited to 17. Would that be a possible option?

DM-37x# iw reg get
country US: DFS-FCC
(2402 - 2472 @ 40), (N/A, 30)
(5170 - 5250 @ 80), (N/A, 17)
(5735 - 5835 @ 80), (N/A, 30)
DM-37x#

This would include Wifi channels 36 - 48


adam

Hello,

We are working in 2.4 GHz range.
Is it possible to limit it in that range?

How we can create NVS file?

Regards,
Dragan

There is an INI file that is used to generate the NVS file and that would limit power. Unfortunately we don't publish that file. I am going to talk to my supervisor and some others to see what kind of options we have to help you get what you need.

adam

Hello,

Thank you. Maybe you can generate and provide us NVS file (which is bin)?

Regards,
Dragan

I just e-mailed you a regulatory database file. If you have any questions, please send any subsequent e-mail requests here as they are monitored by a others as well.

adam

Hello Adam,

We have requirements for this level of WiFi TX Power control also. Do we need to generate an issue on platform support channels to receive updated firmware, databases and instructions?

Derald

Derald,

I e-mailed you an updated regulatory database file. If that doesn't work, let me know on the forum. Other people monitor it too.

adam

Hi Adam,

Thank you. We will try this.

Regards,
Dragan

Adam,

Do you know what the default transmit power in the 2.4GHz band is supposed to be for BSP2.4-4? When we measure get roughly 5-10dBm which seems a little low based on the regulatory requirements. The first question we had is what should we expect as we haven't been able to find an exact value on the forums or in the documentation? The second question is what does it take to get the ability to modify it so we can reduce power or increase it if desired?

Thank you.

Josh,

I am not sure which version of the Torpedo + Wireless you are using, but the power levels vary between the -30, -31 and -32.

The -32 has the highest output power in the 5GHz bands, but we had to lower it a bit in the 2.4 GHz bands when compared to the -31. The -30 hasn't been sold for years, and I doubt you have one of those, but it has the lowest output power which was fixed in the -31 version.

I will dig through our documentation and send you the FCC reports that coincide with the version you're using. Which version of the T+W are you using?

As far as changing the power levels, we can help you lower the power levels, but the power levels cannot be increased and still pass FCC regulations. There are multiple tests when performing the regulatory testing beyond max output power. While increasing the power may get you closer to the maximum permitted power, it will fail other tests like band-edge, band width, etc. so we had to adjust the settings to pass all testing while getting the output to be as much power as we can.

If you want to lower the power levels, let me know and I can have one of the account managers contact you and we can setup a meeting. Generally, we'll go to a test lab, and lower the power levels to what you need and take whatever measurements are necessary, but there is a cost. We have had some customers do this to allow for body-worn applications, etc.

adam

Hi Joshua,

As I know default maximum WiFi Tx power at 2.4GHz should be 20dBm for BSP 2.4-4. You can see it in boot up logs.

Also this maximum power and transmitter usually doesn't operate on it. If there is good link between Tx and Rx side, transmitter will reduce power and increase data rate. Try to place devices in test on bigger distance and see if output power increase.
Also I think Logic PD can support (send) you with image where maximum output power is limited (lower) as per your requirements (I suppose 13dBm) and you can measure it at your own lab. If you want bigger output power than you will need to obtain FCC again.

Regards