
Building a global IoT data network in 6 months - htdvisser
https://medium.com/@wienke/the-things-network-building-a-global-iot-data-network-in-6-months-adc2c0b1ae9b#.r7m9n8458
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pedro_nf
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?

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htdvisser
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...](http://www.lora-
alliance.org/For-Developers/LoRaWANDevelopers)

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IshKebab
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.

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

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johanstokking
Good post, nice summary of a great venture so far

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

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

