Building a global IoT data network in 6 months | Hacker News Reader

Building a global IoT data network in 6 months

medium.com

52 pointshtdvisser9 comments

This project looks great! I don't have much time now to read your specifications etc, sorry. But I have one question: I understand that the Things can send data using low power to the cloud, how did you designed your system for the opposite direction, send data to the Thing like commands, without spending too much energy with the RF receiver? Is the receiver always ON? Is it really low low power?

That's a question we hear quite often. The LoRaWAN specification [1] defines three classes of devices. Class C nodes are powered on all the time, which indeed has consequences for the energy consumption. For more energy constrained devices, Class B offers some kind of scheduled rendez-vous, and Class A devices only receive downlink messages after (in response to) sending an uplink message. This allows nodes to switch of their radio when they don't need it.

[1]: The LoRaWAN specification be downloaded here: http://www.lora-alliance.org/For-Developers/LoRaWANDeveloper...

Thank you for your reply! I'll read the specs this week end.

For comparison, BLE always uses scheduled rendezvous (B), and Thread supports always-on, and unscheduled wake-up type devices (C and A).

The downside of scheduled rendezvous is that both devices need accurate clocks, and they have to communicate regularly (once every few seconds) to maintain synchronisation.

Nice that LoRaWAN supports all three anyway.

Love what you guys are doing here! Very happy to help!

Good post, nice summary of a great venture so far

Do you guys know of any other projects of networks where the infrastructure is owned/crowdsorced by the public?

Not that I know of. I know some cities have made associations to create cable television in the past in The Netherlands. And there are internet exchanges like AMS-X that are owned by a group of companies, but not by the public.

The only low power wide network for IoT I know about is Sigfox (http://www.sigfox.com/en/) but it is not crowd owned...

Reply on news.ycombinator.com