Packet error rate after connection

[Karthik p]

documentation talks about packet error rate but it's not working with Bluetooth stack its running on it's own. what's my problem is data link layer retransmit the malform packet so i need to count the retransmitted packet while running the Bluetooth stack operations is it possible?

Another question I have is, can I use two PCA100565 development kits to check the packet error rate?

regards

Karthik

[Kenneth]

Hello,

I am linking to the v2.5.0 documentation here, though I allways recommend to use the latest available, which at this time of writing is v2.6.0.

You may check out the proprietary feature support for the softdevice controller:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.5.0/nrfxlib/softdevice_controller/README.html 

For the first feature (QoS Conn Event Reports) I can find example of usage in both:
C:\ncs\v2.5.0\nrf\samples\bluetooth\llpm\src\main.c
C:\ncs\v2.5.0\nrf\applications\nrf_desktop\src\modules\ble_qos.c

For the second feature (QoS Channel Survey) I can find it's enabled by following kconfig option:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/kconfig/index.html#!CONFIG_BT_CTLR_SDC_QOS_CHANNEL_SURVEY 

However, I can't find any example of the second feature, but looking at the documentation it looks the above kconfig option will be calling sdc_support_qos_channel_survey(), which then will make it possible to call sdc_hci_cmd_vs_qos_channel_survey_enable() from the application:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.5.0/nrfxlib/softdevice_controller/doc/api.html#c.sdc_hci_cmd_vs_qos_channel_survey_enable 

Which will generate the following event:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.5.0/nrfxlib/softdevice_controller/doc/api.html#structsdc__hci__subevent__vs__qos__channel__survey__report__t 

Surprisingly I can't find any example of handling of the SDC_HCI_SUBEVENT_VS_QOS_CHANNEL_SURVEY_REPORT event, however the handling should be the same as you can find for SDC_HCI_SUBEVENT_VS_QOS_CONN_EVENT_REPORT in the two above mentioned files for the first feature.

Edit also check out the following for reference:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.5.0/nrf/applications/nrf_desktop/doc/ble_qos.html 
https://github.com/nrfconnect/sdk-nrf/blob/main/applications/nrf_desktop/src/modules/Kconfig.ble_qos 

Kenneth

[Karthik p]

Hi Kenneth 

This is the link for blog that talks about DTM in this they just test PHY radio but not packet error rate  Using nRF Connect SDK and west to compile and program the DTM example into the nRF52840 DK I can get the packet error rate at the time of advertising using sniffer.

Check out this question https://devzone.nordicsemi.com/f/nordic-q-a/25541/nrf52-bit-error-rate-measurment read the answer for this question he is telling that there is no example to find the bit error rate! 

And one more thing is wearing about bit error rate is important?

Karthik 

[Kenneth]

Hello,

Your original post asked about having a way to monitor packet error rate when a link is established. So I tried to answer what we can provide in that regard.

The DTM you are asking about now is not used for any functional link. The DTM is used during prototype verification to verify that your designs performs as intended. So it provides a way to for instance measure a lot of electrical parameters (e.g. carrier accuracy, drift, packet errate rate etc). 

How to use DTM is explained in the documentation:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/bluetooth/direct_test_mode/README.html 

You can also find this useful:
https://infocenter.nordicsemi.com/topic/struct_appnotes/struct/appnotes_nan34.html 

Kenneth