Extend your battery life with nRF Cloud's CoAP interface

RE: Extend your battery life with nRF Cloud's CoAP interface

TilakLakshmana — Mon, 28 Apr 2025 13:01:20 GMT

Hello Tuomas, Regarding "Using TCP-based protocols with NB-IoT can be problematic since NB-IoT is not required to support TCP, according to its 3GPP specification. Therefore, introducing the CoAP interface, which is a UDP-based protocol, enables the utilization of NB-IoT features and a reliable connection to nRF Cloud, regardless of which cellular technology you are using."

How is DFU achieved when CoAP uses UDP? Can you share some pointers on how reliability is achieved with DFU?

Thanks,
Tilak

RE: Extend your battery life with nRF Cloud's CoAP interface

Harald — Fri, 29 Sep 2023 15:43:18 GMT

I like the idea of comparing MQTT with CoAP. However, I missed several details. In 2018, we have already measured the energy consumption with NB-IoT (UDP) without a layer to secure it with LoRaWAN and Sigfox. We compared 12, 24, 64 and 512 bytes at 134, 144 and 154 dB link budget. See https://www.akoriot.com/white-papers/
In the long test series, you can see +/-4dB in the RSRP.
If you transmit every 60 minutes for 3 hours, that's only 3 transmissions. If I take the jumps from our test series as a basis, then there is a very high probability of very random results.
I also miss the RSRP specification. At high field strengths, MQTT and TCP cause many repetitions due to packet loss. At low field strength, MQTT will consume more power than CoAP.
If you are using a stack for CoAP, as Achim mentioned, then you should mention which one you are using. The same goes for TCP / MQTT. Within TCP/MQTT you should mention how many retransmissions have been set.

Figure: Measurement series from the study

RE: Extend your battery life with nRF Cloud's CoAP interface

Achim Kraus — Fri, 29 Sep 2023 07:57:46 GMT

Does it support a "graceful restart" for the DTLS context?

And to be frank:

I would have expected at least a small note about the initiating work in the open source project Eclipse/Californium , which started the DTLS 1.2 CID development already end of 2019. I don't know, which implementation your service is using, but I guess, if it's not Californium itself, it's at least based on the experience with that implementation.