DECT-NR+ modem state Questions

[schnitzlein]

Hello,

I am using the modem firmware 1.0.1 for DECT-NR+.

nrf_modem_dect_phy_modem_cfg in the latency field contains fixed delays in modem time units.
Are those automatically used respectivly if the Tranceiver turns on when I call the

nrf_modem_dect_phy_tx(...) for the next transmission.

Is the IDLE_TO_TX delay already included in the sendtime I insert or is it just a value I should take care of and use it if

I want to know exactly how long takes the Tranceiver until it is really sending out data?

Same for the IDLE-TO-RX is the question?

Is there a way I could "see" it with modem states ?


I can observe it with SDR ofcourse, but there is already a serializing/processing and ToF also included in this observing.


Do you maybe have a answer to this?


kind regards
Christoph

[Øyvind]

Hello Christoph, 

I have forwarded your questions internally to get a proper answer. I will provide your with answers by end of tomorrow or Monday. 

Kind regards,
Øyvind

[Øyvind]

nrf_modem_dect_phy_modem_cfg in the latency field contains fixed delays in modem time units. Are those automatically used respectivly if the Tranceiver turns on when I call the nrf_modem_dect_phy_tx for the next transmission.

These latencies represent the minimum guaranteed time the MAC/L1 modem user must account for when initiating an operation, starting from the operation call to its actual execution. For example, when using 0 ("immediately", meaning as soon as possible) in the start_time field for the nrf_modem_dect_phy_tx() function, the RF sample transfer begins at the antenna. However, this timing is not exact but rather a best-effort estimate.

Is the IDLE_TO_TX delay already included in the sendtime I insert or is it just a value I should take care of and use it if

I want to know exactly how long takes the Tranceiver until it is really sending out data?

The explanation above addresses this: latency includes the time it takes for the operation request to propagate until the RF begins the transfer, representing the minimum delay. If start_time is not set to 0, longer delays can be applied from the current time (which can be obtained using the nrf_modem_dect_phy_time_get() function, with processing margins added, or based on DECT received packets and frame timing known by the MAC).

Same for the IDLE-TO-RX is the question?

Yes, the same principle applies: the given latency includes the time from the operation request call to the point where the RF begins reception.

Is there a way I could "see" it with modem states ?

Basically, yes. You can monitor the COEX pin behavior, which can be configured in the modem using the COEXCONFIG AT command.(see Combined configuration of COEX pins %COEXCONFIG in the nRF91x1 DECT NR+ AT Commands)

Kind regards,
Øyvind