Lora is also quite popular for telemetry in High Altitude Ballooning circles, which my local club (http://www.areg.org) is involved in.
As it's patented and a locked down chip set I'm quite interested in open source alternatives. Our FSK modem (same one as used for some FreeDV modes) is allowing us to get much higher bit rates than Lora, e.g. 100 kbit/s with a very powerful LDPC code. We have managed to send HD images over 100km paths using just 50mW: http://www.rowetel.com/?p=5344 At 100 kbit/s with a LNA and $20 SDR dongle the MDS is a rather low -114dBm - which would make analog FM on a HT scratchy. As a next step I'd like to develop custom radio hardware, like a $5 radio board, but fully open and with our high quality modems (many closed chip-set modems under perform). Cheers, David On 28/02/17 11:51, Daniel Mundall wrote: > Hi Steve, > > I think that this is a great idea, we've been playing with LoRa for a > few years now with great results. And now with some SDR libraries > showing up it stands to be an interesting option for UHF Voice/messaging. > > 73's > Daniel > > Daniel Mundall > > On Mon, Feb 27, 2017 at 2:00 PM, Steve <[email protected] > <mailto:[email protected]>> wrote: > > Someone asked me if we could use LoRa modulation on UHF. I said, I > don't know, let me look. > > LoRa is a Chirp Spread Spectrum mode (CSS). Well, the FCC allows > Spread Spectrum on UHF I seemed to recall. Let me check. > > 97.3(c)(8): /SS. Spread Spectrum emissions using bandwidth-expansion > modulation emissions having designators with A, C, D, F, G, H, J or > R as the first symbol; X as the second symbol; X as the third symbol./ > > Boy, this doesn't look good. I find that LoRa has an emission code > of X1D. X because no other emission mode works for spread spectrum. > > Wait a minute. If no other mode works, why did they list all those. > The second and third emission symbols are mysterious, as it is > obviously one channel of data. > > Good Lord. Looks like we can't do spread spectrum on UHF like they > said we could. How about AXX emission mode. AM spread spectrum, hee. > > This isn't very digital voice related, but I always thought > frequency hopping on UHF would make a good voice modem. > > I'm thinking about sending in a petition: > > > https://docs.google.com/document/d/15n1LYDJhhdqRon7j5lM3n2rFlOgoqrk-kCenKtx9YLo/edit?usp=sharing > > <https://docs.google.com/document/d/15n1LYDJhhdqRon7j5lM3n2rFlOgoqrk-kCenKtx9YLo/edit?usp=sharing> > > Have fun, > > Steve > > > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > <mailto:[email protected]> > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > <https://lists.sourceforge.net/lists/listinfo/freetel-codec2> > > > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > > > > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
