AN14114: RF Test Mode on Linux OS

[sert1m]

We are using IW610G with single antenna for our device and preparing commands for FCC test. We have several questions about RF test mode.  
 
FW versions: 
Kernel: lf-6.12.3-1.0.0 
mwifiex: lf-6.12.20_2.0.0 
imx-firmware: lf-6.12.20_2.0.0 

1. Can we start TX on one device and receive packets on another device with same settings (band, channel etc)? As described at step 8 of this manual: 
https://docs.nxp.com/bundle/AN14114/page/topics/5ghz_rx_command_sequence.html 

2. When we are trying to change bandwidth from 40 MHz or 80MHz we receive error in dmesg. It also seems like 80MHz can only be applied to 5GHz band but it is not mention in the manual: 
https://docs.nxp.com/bundle/AN14114/page/topics/set_the_channel_bandwidth.html 

 
Here is when we are trying to change bandwidth to 80MHz on 2.4GHz. 

echo 'rf_test_mode=1' >> '/proc/mwlan/adapter0/config' 
echo 'tx_continuous=0' >> '/proc/mwlan/adapter0/config' 
echo 'tx_frame=0' >> '/proc/mwlan/adapter0/config' 
echo 'radio_mode=11 0' >> '/proc/mwlan/adapter0/config' 
echo 'band=0' >> '/proc/mwlan/adapter0/config' 
echo 'bw=4' >> '/proc/mwlan/adapter0/config' 
echo 'channel=1' >> '/proc/mwlan/adapter0/config' 
kernel: RF test mode cmd error 
echo 'tx_antenna=1' >> '/proc/mwlan/adapter0/config' 
echo 'rx_antenna=1' >> '/proc/mwlan/adapter0/config' 
echo 'tx_power=0 0 0' >> '/proc/mwlan/adapter0/config' 
echo 'tx_continuous=1 0 0x00000AAA 0 3 1' >> '/proc/mwlan/adapter0/config' 

Here is when we are trying to change bandwidth to 40MHz on 2.4GHz. 

echo 'rf_test_mode=1' >> '/proc/mwlan/adapter0/config' 
echo 'tx_continuous=0' >> '/proc/mwlan/adapter0/config' 
echo 'tx_frame=0' >> '/proc/mwlan/adapter0/config' 
echo 'radio_mode=11 0' >> '/proc/mwlan/adapter0/config' 
echo 'band=0' >> '/proc/mwlan/adapter0/config' 
echo 'bw=1' >> '/proc/mwlan/adapter0/config' 
kernel: 5:185m5:185mRFTM_COMMAND ERROR: 0xffffffff 
echo 'channel=1' >> '/proc/mwlan/adapter0/config' 
echo 'tx_antenna=1' >> '/proc/mwlan/adapter0/config' 
echo 'rx_antenna=1' >> '/proc/mwlan/adapter0/config' 
echo 'tx_power=0 0 0' >> '/proc/mwlan/adapter0/config' 
echo 'tx_continuous=1 0 0x00000AAA 0 3 1' >> '/proc/mwlan/adapter0/config' 

We still can see that bandwidth parameter was applied in the config. Is this error code critical? 

hardware_status=0 
netlink_num=31 
drv_mode=7 
hssetpara=7,0xff,200,400 
sdcmd52rw=0 0x0 0x00 
rf_test_mode=1 
tx_antenna=1 
rx_antenna=1 
band=0 
bw=1 
channel=1 
radio_mode[0]=11 
radio_mode[1]= 
total rx pkt count=0 
rx multicast/broadcast pkt count=0 
rx fcs error pkt count=0 
tx_power= 
tx_continuous=1 0 0xaaa 0 3 1 
tx_frame=0 
he_tb_tx=0 
trigger_frame=0 
otp_mac_add_rd_wr= 00:00:00:00:00:00  
antcfg=0x1 

3. IW610G supports 802.11n/a/g/b and 802.11ax. For TX  Frame and TX Continuous there is possibility to set data rate. It depends on the standard.  

https://docs.nxp.com/bundle/AN14114/page/topics/data_rates.html 

But some data rates do not apply and generate error. For example: 

echo 'rf_test_mode=1' >> '/proc/mwlan/adapter0/config' 
echo 'tx_continuous=0' >> '/proc/mwlan/adapter0/config' 
echo 'tx_frame=0' >> '/proc/mwlan/adapter0/config' 
echo 'radio_mode=11 0' >> '/proc/mwlan/adapter0/config' 
echo 'band=0' >> '/proc/mwlan/adapter0/config' 
echo 'bw=0' >> '/proc/mwlan/adapter0/config' 
echo 'channel=1' >> '/proc/mwlan/adapter0/config' 
echo 'tx_antenna=1' >> '/proc/mwlan/adapter0/config' 
echo 'rx_antenna=1' >> '/proc/mwlan/adapter0/config' 
echo 'tx_power=0 0 0' >> '/proc/mwlan/adapter0/config' 
echo 'tx_continuous=1 0 0x00000AAA 0 3 47' >> '/proc/mwlan/adapter0/config' 
kernel: 5:185m5:185mRFTM_COMMAND ERROR: 0x0000001b 

Config still looks like settings were applied. Is this error code critical? Is there any description for such error codes? 

hardware_status=0 
netlink_num=31 
drv_mode=7 
hssetpara=7,0xff,200,400 
sdcmd52rw=0 0x0 0x00 
rf_test_mode=1 
tx_antenna=1 
rx_antenna=1 
band=0 
bw=0 
channel=1 
radio_mode[0]=11 
radio_mode[1]= 
total rx pkt count=0 
rx multicast/broadcast pkt count=0 
rx fcs error pkt count=0 
tx_power= 
tx_continuous=1 0 0xaaa 0 3 47 
tx_frame=0 
he_tb_tx=0 
trigger_frame=0 
otp_mac_add_rd_wr= 00:00:00:00:00:00  
antcfg=0x1 

[shaun_wu]

Hello @sert1m 

Can we start TX on one device and receive packets on another device with same settings (band, channel etc)? As described at step 8 of this manual: 

--> It is ok, but why you do so? If you are trying to use antenna to test rf signal, please make sure radio environment is good.

When we are trying to change bandwidth from 40 MHz or 80MHz we receive error in dmesg. It also seems like 80MHz can only be applied to 5GHz band but it is not mention in the manual: 

--> 2.4GHz not support 80MHz bandwidth.

But some data rates do not apply and generate error.

--> The datarate should match modulation method, you could search internal for the corresponds relationship.

Best Regards

Shaun

[sert1m]

Hello @shaun_wu !

Thank you for our response! 

It is ok, but why you do so? If you are trying to use antenna to test rf signal, please make sure radio environment is good.

--> We are trying to test anthena. Unfortynatly, when we start RX on one device and TX on another with the same band, modulation, chanel etc, we cannot see "rx pkt count" etc to be changed. 

2.4GHz not support 80MHz bandwidth.

--> Got it. But what about error "kernel: 5:185m5:185mRFTM_COMMAND ERROR: 0xffffffff " what we set 40 MHz bandwidth? Should it be ignored?

The datarate should match modulation method, you could search internal for the corresponds relationship.
--> Got it, thank you! We will search for it. 

[shaun_wu]

Hello @sert1m 

Your test case is like a signalling test, it is different from non-signalling test. For signalling test, you should make DUT work as STA or AP. So that DUT could receive or transmit to destination correctly. wi-fi communication needs pairing, connection ect..

Got it. But what about error "kernel: 5:185m5:185mRFTM_COMMAND ERROR: 0xffffffff " what we set 40 MHz bandwidth? Should it be ignored?

--> I observe your input already vailed in configure file, so, no problem.