LoRa Range Testing in San Francisco
blog.beepnetworks.com
blog.beepnetworks.com
If the transmitter could be inductively charged in a dog crate or where I park my bike -- it would be very convenient too. Ping time could be much slower, even once a minute would be plenty fast. Appears you could get 24 hours transmit and gps without too much trouble in a pretty small package.
I love the idea of inductively charging the dog tracker when the dog is in bed (though we're unlikely to pull that off anytime soon given the state of wireless charging).
You can do a lot with battery life if you only turn the GPS radio on when the user wants to locate the item. This type of product requires really good network coverage. We could make one last for 4-5 months on a single AAA battery.
If you want it to check in every 10 minutes with GPS data it would only last for 3.5 days. If you get smart with an accelerometer you can push that out to 1-4 weeks or more depending on how much the thing you're tracking moves around.
It's a fun product area with lots of parameters to tweak!
Here is a summary of my black box/blind signal analysis that informed its design. https://github.com/matt-knight/research/tree/master/2016_08_...
If, on the other hand, this hardware mounted on one of my buildings can cover my 70 acre farm and a bit of the valley around it, I could find a use for it.
Maintaining one radio is one thing, maintaining ten of them is another. Each one has a battery to worry about as well, can go bad, can be misconfigured, etc. Whereas if I have one radio on the roof my house or barn there is less to go wrong.
There is also no promise adding more nodes to a mesh network will improve performance since the nodes can interfere with each other. There is a huge literature on mesh networks because the area gets huge amount of military funding, and maybe the military really can use them, but I think they are a solution looking for a problem in an environment where people act as if wires were ritually unclean.
@PaulHoule those are some good points. I would've agreed up until recently, but the newer IoT mesh radios have gotten surprisingly robust. The frequency modulators and collision detection baked into the last few iterations of lower cost IoT chips (like DigiMesh/Nordic chips) really have improved. We've been using DigiMesh 900 MHz units in a greenhouse setting with great success (especially compared to 2.4GHz which drops packets with abandon), with no measured packet loss to date. Pretty sweet!
To wrap that up, low-throughput but hi-scalability mesh networks combined with better firmware, network configuration, tuned mesh protocols, and proper software support to make the "throw a few of these down and forget them" scenario a real possibility. Check out the Beep networks blog for a longer explanation: http://blog.beepnetworks.com/2016/09/messy-networks-for-the-...
Big on words, but not speaking about others ;)
I'd suggest anyone interested in LPWAN (be it Sigfox, LoraWAN or else) to get its own idea by field testing. Talk is cheap. Sigfox coverage is available in 25 countries, including some large US cities (SF, NYC, Chicago, Atlanta, ..) http://www.sigfox.com/coverage
Get in touch if interested by more info about Sigfox, solutions for developers, etc.. http://makers.sigfox.com
The most interesting place to see is in the Netherlands, followed by the Zürich area in Switzerland.
In my experience it's easy to get miles of range when you have line of sight. Just look at the measurement from nearby Lucerne to Zürich (Switzerland). That's around 50-60km. If you have buildings in the way, things get tougher. Putting up gateways high on the roof helps.
The Things Network Forum (https://www.thethingsnetwork.org/forum/) is always a good place to talk about these things.
I imagine the low throughput of LoRa would make encryption a greater challenge than with other modules, but maybe there are other reasons for that.
The radio chip itself doesn't perform the encryption though, it's done on the host microcontroller.
What kind of things are you monitoring?
Sporadic long range channels could be a bug and not a feature for this kind of system because if you are not a ham who thinks it is a blast to talk to someone 500 miles away on a a handheld, you want a radio system to work predictably and not be interfered with by distant stations.
I am working as consultant for a startup building a backend for LoRa devices. If you have any question from the backend software point of view feel free to write me :)
email in the profile.
The gateway is extremely simple it receive messages and send them to a bigger server (usually via Ethernet).
Of course the scale of your problem is dependent of the legislation... In Europe (where I work) there is a duty cycle of 1% (if you talk for 1 second you need to don't talk for the next 100 seconds).
Also keep in mind that device usually trasmit at 14 dBm WAY lower than the 27 dBm in the article. Every 3 dBm half the actual power...
So the distribution is not uniform... On the other way, once an area is covered, more and more nodes are added.
900mhz, miles of range, dial-up modem speeds.
Unfortunately the spectrum that's available for this type of thing varies significantly country-by-country, so it's unlikely to be added to a major phone maker.
Go beep!
BTW, so, uh...hey beep, wanna sponsor a hackathon for this stuff this spring?
You mean in 9 months? We're hoping to do one earlier than that :). Hit me up: shawn at beepnetworks dot com
The FCC limits time spent transmitting in a single channel ("time on air"), but there's no duty cycle limit if you follow the channel hopping rules.
We go beyond LoRaWAN with our own protocol for some use cases.
For those following along: LoRa is a wireless encoding technique (PHY layer), LoRaWAN is a protocol for how a large group of devices should structure their packets (MAC layer).
EDIT: Actually I suppose since it isn't LoRaWAN, it could be 433 MHz.
In the blog post we were using 27dBm transmissions. At that level the radio and power amplifier draw about 1.5W. If a transmission takes .3seconds that's .5Watt-seconds. So with a single AA battery (about 5Wh) you can do 40000 transmissions.
Transmissions can be much shorter in time depending on radio parameters, by a factor of 32 at most, but range can be affected.