what should I provide for DTM tests

Question

Im trying to provide DTM functionality for certifications tests. I can't setup an UART interface, I found the below code which tries to use DTM without UART. it uses channel variable to change the frequency.

 static uint8_t packet[256];

generate_modulated_rf_packet()
.....
NRF_RADIO->PACKETPTR = (uint32_t)packet;
...

main :

.......
advertising_start();

radio_disable();
    generate_modulated_rf_packet(); // fill the packet array declared above with random
    NRF_RADIO->SHORTS     = RADIO_SHORTS_END_DISABLE_Msk | RADIO_SHORTS_READY_START_Msk | \
                            RADIO_SHORTS_DISABLED_TXEN_Msk;;
    NRF_RADIO->TXPOWER    = (RADIO_TXPOWER_TXPOWER_Pos4dBm << RADIO_TXPOWER_TXPOWER_Pos);
    NRF_RADIO->MODE       = (RADIO_MODE_MODE_Ble_1Mbit << RADIO_MODE_MODE_Pos);
    NRF_RADIO->FREQUENCY  = channel;
    NRF_RADIO->TASKS_TXEN = 1;
......
main_loop();  // here timers and BLE communications (services and characteristics R/W/N/I)

my question is:

1 woul all my communications use the frequende channel

2 would this program send the packet packet and if so, how many times

3 and the most important : whould this be useful for DTM tests (I don't really get the purpose (I was asked by certifications tests !!))

the idea is to provide many hex files each with difference frequence