LoRa mesh networks


#1

Did anybody think about using mesh networks for communication with the Librem5?
The easier path would be to use an existing product such as the https://gotennamesh.com/products/mesh
Or one of the systems that are in development or have slightly different use cases:

But the best solution would be, if the transceiver was directly built into the device.


Possible privacy enhancement?
#2

Instant bookmark. Thanks for a cool topic I knew nothing about!


#3

Yes.


I think the trade-offs would be

  • how conventional a phone is this intended to be and what does the target market expect?

  • how much can you stuff inside the device, taking into account physical space, heat dissipation and power consumption?

You will note that the first link above implicitly talks about taking out the cellular modem and replacing it with a LoRa card. That’s a good feature of a modular design. You are free to do that.

Would it work? Who can say but I would kind of like something that just makes conventional phone calls before exploring the full potential.


#4

That’s a good idea, or onto the device in the form of an external add on case (because of the USB-C )


#5

I think it would be a very fun experiment, though it would definitely be a niche type functionality.

According to this article by Ars the bandwidth is about 300 bits/s. 300. That’s…not a lot.

However, instead of working on the baseband card, I think a WiFo/LoRa combo card (I don’t need BT, so I’d be fine replacing the BT with LoRa) so you could connect to both a traditional wifi network and a LoRa network (mesh or DIY) would be a super cool. I don’t know if such a card exists, but I’d buy it if it does.


#6

Maybe people whose use case is “convergence” do want BT. How about a WiFo/BT/LoRa combo card? It’s not as if 300 bits/second is going to require a lot of processing on the card. :slight_smile:

It wasn’t all that many years ago that I could test a 56 kbit/s modem - and even that was near unusable on “modern” web sites. So I think we can guess that LoRa won’t be any good for web. Maybe it is OK for basic chat (textual communication).


#7

I have several BT devices I connect to for convenience so lack of Bluetooth would be a huge negative for me


#8

As Librem 5 Wi-Fi card is compliant to M.2 2230 dual module E-Key standard (@amosbatto, it looks alike to me) and might easily be that it carries 75 pins (needs to be confirmed by you @richi or otherwise), than someone interested can try to replace it and play with the Advantech WISE-1510WMB-SDA1N because it has 75 pins, if software ready/compatible of course. WISE-1510 FCC certification link is here and LoRa Test Report (EU version) here. Another option in order to preserve Wi-Fi card would have a need to involve Purism team to implement the same or some other LGA module like muRata CMWX1ZZABZ directly on PCB (external host), having FCC certification and Conformance to the LoRaWAN® Specification V1.0.2. Thanks for this thread, all new to me, but still some kind of relaxing topic on Low-Power Wide-Area Network (LPWAN) Applications involving spectra of 863-870MHz for Europe, 920-928MHz for Japan and 902-928MHz for North America!


#9

For security reasons, the Librem 5 is probably not going to use the PCIe lane pins (or the SATA pins) on the M.2 interface though - so if the card is using those pins, it probably won’t work.

At a quick look, the card does not appear to use those pins, but it does use a bunch of other pins and I have no idea whether those pins are essential to the card and/or connected anywhere on the phone side.


#10

Ok, I am giving up on WISE-1510/WISE-3610 (YouTube presentation) LoRa implementations as it looks like that only Semtech Corporation offers open source software for their products. LoRa related openSUSE link is here.


#11

Luxury! In my day we connected via 14.4 to compuserve and BBS’ …and that’s the way we liked it!! Sorry, gonna be an old here and say that most UX is just annoying waste of time to me. Perhaps ‘new’ sub-markets (/ view in options) should be forged too.
…I think I legally somehow have to follow that with “get off my lawn”…so there you go :wink:


#12

We had to drive to the store to get our software on an audio-cassette tape and then plug that cassette player into our computer waiting for half an hour for it to load, then enjoy our sprite driven games on a 640 by 480 used forty-pound glass-tube Color TV set.


#13

LoRaWAN features a raw maximum data rate of 27 kbps (50 kbps when using FSK instead of LoRa), and claims that a single gateway can collect data from thousands of nodes deployed kilometers away. Also, one of the main advantages is that such networks are low power optimized (pages 5 and 18):


#14

Luxury. I remember when we didn’t need to bother with a ‘k’ in the baud rate. :joy:


#15

Thanks for that info! 27 kbps isn’t terrible. Granted, we’ve grown accustomed to MUCH higher. 27 kbps is something you could plan for. Definitely something I’m going to keep an eye on.


#16

The LoRa band in the US is at 902 MHz to 928 MHz. All US amateur radio licensees have user privileges accross exactly this same band. In fact, the amateur radio users were there long before LoRa came along. But this band was never popular and went largely unused until LoRa came along and started producing chips for the commercial use of LoRa, which the amateur radio community soon put to use also. I read one article where an amateur radio operator used LoRa technology and a 25 watt rf amplifier to communicate over 200 miles, legally (as an amateur radio operator). Typically the Amateur Radio Relay League goes on the warpath, any time commercial interests threaten the use of the amateur radio bands by amateur radio operators. From what I can tell, they have remained either silent or maybe even favorable to LoRa radio systems on 902 MHz to 928 MHz. If commercial use of a band becomes too prevalent and amateur use too disruptive to the commercial use, the FCC can simply remove that band from legal use by amateurs. Much of the development of LoRa by amateur radio hobbyists has been done by the Tucson Amateur Packet Radio (TAPR) group. A Librem 5 m.2 modem for LoRa use would probably be put to use quickly by the amateur radio community. Someone should contact the TAPR group if the L5 could feasibly host a LoRa modem. The firmware and linux software for full LoRa L5 to L5 communications and maybe even a few repeaters would probably materialize soon after those who are already running experiments there start ordering and getting their Librem 5 phones. It’s been maybe ten years since I’ve ordered anything from TAPR. But they used to be a very active group with several projects all going on at the same time. Typically the group would settle on a schematic and pool their money. Then PCBs would be fabricated and electronic components ordered in volume so that everyone who took part would get a kit. Then everyone would assemble their own kit and work together (mostly online) to write the needed firmware and software. Everything related to the projects get published online.


#17

As said, all new to me, but skipping through this presentation I “went to visit” Tucson, AZ, USA “over” LoRa APRS Gateway.
And, with all respect toward author (and hopefully without spamming), here is link to some practical (and funny) usages (based on open source platforms and applications) based on one LoRa Gateway (with links to LoRa32u4 II SX1276 LoRa Module or Adafruit Feather 32u4 RFM95 LoRa RadioFruit). Another link to ESP32 with LoRa using Arduino IDE (with example of measuring soil moisture and temperature) is here.
Here are two additional hardware overviews:

P.S. As already mentioned Advantech WISE-1510 is based on SX1276 transceiver chip, but if this helps here, within this thread, I don’t know.


#18

This is all very good information. LoRa should be good for APRS use since for the most part, only location data and station (Amateur radio call-sign) data is transmitted in APRS and thus this is a very low data rate, intermittent-use application which LoRa is intended for by design.

I was also surprised to see that per the presentation, the use of LoRa on 915 MHz requires no license by the users. Since all use of the RF spectrum below 300 GHz is regulated by the FCC in the US, this means that the use of LoRa must be licensed by statute, if true. Since 902 MHz to 928 MHz is protected for use under part 90 (commercial and public service use) on a primary basis with use also allowed by amateur radio operators on a secondary basis, this leads to only one conclusion that I can think of that would make the use of LoRa for unlicensed commercial use on 915 MHz possible. The commercial implementation of LoRa must be licensed by statute under part 15 (low power devices below 100mW power). At 915 MHz, long range low data-rate use at 100 mW is feasible. But it’s probably a good guess that most if not all amateur radio LoRa digipeaters probably operate at fifty to five-hundred times that much power (5 to 50 watts transmitted). In such a system, only an amateur radio license (under FCC part 97) or a part 90 commercial or public service license would allow legal operation and the amateur and commercial systems would need to be completely separate from eachother and not capable of communicating with eachother. Going back to the Librem 5, this would allow the legal use of LoRa in an m.2 modem card at very low power for every unlicensed user and at as much power as the modem card can possibly put out for amateur radio users. But access to any part of the amateur radio mesh network would be prohibited for unlicensed users in such a case. The use of such an m.2 card in the Librem 5 would then require an implementation in either hardware or software, of a separate network with no node in that unlicensed network being capable of transmitting more than 100 mW of power. Whether or not a user could obtain a part 90 (commercial or public service) license for a higher power use of LoRa at 915 MHz is a good question. In certain circumstances, it may be worth giving up access to traditional cell phone communications, in exchange for access to a LoRa network, especially as meshes fill in. Given the much greater advantages of higher power handsets and access to high power mountaintop repeaters, the first practical uses of LoRa in such a case will probably occur in the amateur radio community if a good consumer application surfaces. In the early cellular systems, towers were very far apart and you needed a phone mounted in your car and a good rooftop antenna to reach the tower. As the number of subscribers increased, it became economical to put cell towers almost everywhere, making all communications in those same systems be low power, shorter range communications. Perhaps the LoRa systems will develop similarly.

Another thing to consider is the restriction to relative line-of-sight radiowave propagation at 915 MHz. If you transmit a signal of 10 KW in to a mountainside you’re more likely to start a fire where the signal hits the mountain, than you are to have your communications be received from that same signal on the other side of the mountain. This might be a bit of an exaggeration, but not by much. Even at 440 MHz at only 5 watts, you generally can’t make out of your own neighborhood without a repeater unless you live on a large hill. On a flat terrain at 100mW at 915 MHz and without a mountaintop repeater, only your nextdoor neighbors will receive your signal. That is why no license is required. Even with much more power, but without a mountaintop repeater, your signal will go nowhere that will be received. Altitude is everything and increased transmitting power only helps marginally. A 100 mW LoRa signal from a parabolic dish might even be detectable on the moon if there was anyone there and a big enough antenna there to receive it.


#19

@StevenR, I believe that you have been missing this link: http://www.kh-gps.de/lora.htm that relates to the author of previously uploaded presentation here (bottom link of every slide is his homepage address). Even if this link is relatively late reaction of mine, you brought up several things that need to be considered (because of such regulations in every country). Thanks for your input as it is of great value! As well, this simple explanation: https://lora.bitnet.be/loraprs.html confirms that you know what you are talking about, for example by bringing up the flavor of 433.05 - 434.79 MHz frequency band (LF), called EU433. My input was related to LoRa in general, broader terms and not directly to some commercial operators or amateur radio communities. If someone ever start to use Librem 5 on LoRa network (private or commercial) then we will rise our awareness, up to the next level, on how to legally/properly use our device (and on which frequency and where): https://lora-alliance.org/resource-hub/lorawanr-regional-parameters-v11rb.


#20

OK but at 50 kbps I won’t be jumping to use this for communication.

Could be OK for simple web pages without graphics, not the bloated pages that proliferate these days. Unclear how well it would handle the needed application-level encryption, which imposes additional overheads, and additional handshaking, before you even get to a simple web page.