Where can I find the presentation for the "Best Practices for Cellular IoT Development" webinar?

[Bjørn Kvaale]

Where can I find the presentation for the "Best Practices for Cellular IoT Development" webinar?

[Achim Kraus]

All Theory is gray

Just as an idea:

Last weekend I started a small "battery runtime" experiment with a Thingy:91 using NB-IoT and CoAP/DTLS CID, see Zephyr CoAPs Client.

Let's see, how long and stable that runs from battery. You may watch the progress by yourself using libcoap:

coap-client coap://californium.eclipseprojects.io/echo/cali.352656100985434

219831 s, Thingy:91 v0.3, 0*60, 1*1, 2*0, 3*0, failures 0
4114 mV 89% battery
RSSI q,p: 255,255
Network: NB-IoT
Released: 53 ms

"219831" (uptime), "0*60" 60 exchanges without retransmission. "1*1" 1 exchange with 1 retransmission.
"4114 mV 89% battery" explains itself.

That test uses PSM and wakes up every hour exchanging that simple message.

So setup a similar demonstration of a battery powered Thingy:91 with LTE-M or NB-IoT and the protocol of your choice. Please use encryption, as my CoAP/DTLS CID demo does as well. Choose a communication configuration, which fits best to the approach you want to show.  

I'm looking forward to your results.

[Achim Kraus]

Just if someone is interested in the outcome:

I used two devices for the test.

One stopped after 4 weeks at 50% battery (nRF9160 - sent UDP message do not longer reach destination after 4 weeks .

A second one reach almost 7 weeks with 5% battery left.

4095883 s, Thingy:91 v0.4, 0*1086, 1*49, 2*1, 3*0, failures 1
3663 mV 5% battery
RSSI q,p: 255,255
Network: CAT-M1 5,26201(*)
PSM: TAU 3600 [s], Act 8 [s], Delays 0, Released: 12402 ms
Stat: 323,302,291,279

The test was done with the UART and 3.3V enabled. That causes a quiescent current of about 0.8mA. Disabling UART and 3.3V results in only 0.04mA, which will make the device run much longer.