Live data from Hacker News

How New Long-Range Radios Will Change the Internet of Things

medium.com

71–80 of 109 posts

Re: How New Long-Range Radios Will Change the Internet of Things

#71
I wonder how it will scale. Sure, you can use spread spectrum but to other unlicensed users it will look like the noise floor is increasing. As more people connect, the more noise there will be, and the players will either increase their power to maintain their SNRs, or have to slow down their rates.

Re: How New Long-Range Radios Will Change the Internet of Things

#72
post #24
post #21

Earlier quoted context omitted.

Compromise is you'll get a few bits to 1kbps at best over a few Km of range. It would work for some applications but not for all of them.

This is all that IoT needs, though. It's not about streaming video or music or something, it's about a sensor that goes high when somebody is sitting in a chair, or that sends an integer value once every few minutes.

... so why not do it over WiFi? You use less power/bit and you get the data delivered to where it matters, local network.

LoRa only makes sense (and I've seen it used) in large infrastructure type uses like sensors that monitor roads or bridges.

Re: How New Long-Range Radios Will Change the Internet of Things

#73
post #60
post #50

Earlier quoted context omitted.

Just curious – why is range limited by a protocol? Why couldn't you send Bluetooth over hundreds of miles with a big enough antenna, for example?

You can amplify a signal and send it far. But due to FCC regulation in the 900MHz band for example you can only instantaneously transmit at 30W. Another way to make a signal go further is to transmit at a lower data rate (thus spreading your signal out over time so that in effect you have more power in the signal). The FCC limits "dwell time" in a single channel to .4s in the 900MHz band. Yet another way to increase…

> But due to FCC regulation in the 900MHz band for example you can only instantaneously transmit at 30W.

The limit is actually 4W ERP (1 watt transmit + 6dB antenna gain) per CFR 15.247: https://www.law.cornell.edu/cfr/text/47/15.247

If you are aware of an exception to this, I would be very interested.

Re: How New Long-Range Radios Will Change the Internet of Things

#74
post #72
post #24

Earlier quoted context omitted.

This is all that IoT needs, though. It's not about streaming video or music or something, it's about a sensor that goes high when somebody is sitting in a chair, or that sends an integer value once every few minutes.

... so why not do it over WiFi? You use less power/bit and you get the data delivered to where it matters, local network. LoRa only makes sense (and I've seen it used) in large infrastructure type uses like sensors that monitor roads or bridges.

I think you answered your own question -- of course WiFi makes sense for small/short range networks. Its cheap and fast.

These technologies are more exciting because you are talking about realistic coverage areas of square kilometers with inexpensive, unlicensed radios. Think of something like a large natural gas pumping field -- there are tons of industrial sensors and controls spread out over a fairly large area that don't need to send much data. I work in the radio industry, and these technologies, if they live up to their hype, will be industry disrupting.

Re: How New Long-Range Radios Will Change the Internet of Things

#75
post #2

Lower power, but highly processed radio signals are fascinating to me. I've been playing with WSPR on the 10 meter band which is fixing (hopefully) to open up a little here over the next couple of months. With about 1/10th of the power of my Wi-Fi router and a long wire over top of the house, I've been picked up so far this year in California from Ohio. Last year I was heard almost daily in Europe. A blogger I follow…

Ok, since there are some radio wizards in this thread: if I want to log low bandwidth sensor data (so < 1kbps) on a unidirectional (if that helps) link over ~ 500m, almost clean line-of-sight with some trees in there, what are my options? I'd prefer to spend little money and use little power on the sensor end. I'm considering an ESP8266 (so 802.11) with a high-gain directional antenna. Sender and receiver are fixed l…

ESP8266 is worth checking out because its dirt cheap, but it really depends how "clean" your line of sight is. 900 MHz radios will have better propagation. Might want to check out something like this: http://rpi900.com/hardware/introduction.html

Re: How New Long-Range Radios Will Change the Internet of Things

#76

> So now you can buy a radio chip for a few bucks and add it to any device. Where? > Think kilobits-per-second, not megabits-per-second. Well, voice is (or was...) 32kbps, so technically you could make a voice call over these radios, if they can give you 32kbps? I've heard of voice compression as low as 8kbps too. Imagine a cellphone that lasts months :)

Codec2 is an open source speech codec, shooting for 700 - 3200 bit/s, specifically for digital voice over radio.

http://www.rowetel.com/blog/?page_id=452

Re: How New Long-Range Radios Will Change the Internet of Things

#77
post #3

I'm intrigued. Anyone want to suggest an economical development board or transceiver?

This is quite simple board to use, it provides UART interface to the LoRA module and can be used with microcontroller or USB com port interface: https://www.tindie.com/products/DORJI_COM/long-range-semtech...

Re: How New Long-Range Radios Will Change the Internet of Things

#78
post #33
post #23

Earlier quoted context omitted.

What tech are you using for the base station? I'd love to put one in our hackerspace out here :) -- a few offices of people working on IoT would probably think that was pretty cool.

Killer -- where's your hackerspace? LoRa basestation gateways are available off-the-shelf for from Kerlink, Multitech, and Link Labs. The gateways are actually quite simple, they just forward packets to the cloud network server, and back to the clients.

Hey, is there any chance for us putting something like this to the Taipei Hackerspace (Taiwan)? https://taipeihack.org

I've been checking LoRa for months to do some projects, but all got to some bottlenecks. (E.g. here are some notes on a USB-stick LoRa communicator plans: https://hackpad.com/LoRa-USB-Communication-Stick-xKGgChuwbzL )

Re: How New Long-Range Radios Will Change the Internet of Things

#79
post #33
post #23

Earlier quoted context omitted.

What tech are you using for the base station? I'd love to put one in our hackerspace out here :) -- a few offices of people working on IoT would probably think that was pretty cool.

Killer -- where's your hackerspace? LoRa basestation gateways are available off-the-shelf for from Kerlink, Multitech, and Link Labs. The gateways are actually quite simple, they just forward packets to the cloud network server, and back to the clients.

Can I run my own server?
Post reply on HN