[amsat-bb] Outernet L-Band now carries AMSAT and ARISS weekly bulletins

Wed Mar 14 19:40:11 UTC 2018

I noticed another news story from Outernet and I have some comments.

For those who don't know Outernet is a "commercial" /for the greater
good, satellite downlink only service providing low bandwidth data,
aimed at filling and updating a hard drive with news and info, aimed
at developing nations, a free to receive data stream, for educational
purposes etc. Their latest stunt/change is to downlink on 12Ghz from a
Geostationary satellite, with reception without using a satellite
dish, but instead just a bare LNB pointed in the direction of the
geostationary satellite, using the gain of the horn inside the LNB.

News stories here:
https://hackaday.com/2018/02/22/at-71572-km-you-wont-beat-this-lora-record/

https://store.outernet.is/blogs/the-official-outernet-blog/world-record

https://www.indiegogo.com/projects/lantern-a-global-satellite-data-radio

I would hesitate to recommend this system, as it is vapour-ware at the
moment, and all the previous kits/hardware released have been dropped
and made obsolete by changes to the broadcast. Previous broadcasts
were 12Ghz geostationary, but decoded using a DVB-S tuner demodulator,
then they changed to L-band low earth orbit immarsat and now they are
back on geostationary, this time with a new modulation scheme making
pointing easier. They are using the "LoRa" standard, basically just
using a protocol that allows low signal margin decoding ( Chirp Spread
Spectrum modulation (CSS) which trades data rate for sensitivity
within a fixed channel bandwidth. ), similar to WSJT/PSK31 and other
low data rate weak signal modes.

It is interesting they thing that a bare LNB (about 80 degree beam
width) that seems to be doing the trick, although they also show
pictures of patch antennas which presumably are designed for narrower
beam width more suited to this.

The main caution I would have is they seem to be constantly peddling
hardware, which soon becomes obsolete, without in fact any real
business model to fund the venture. They claim their business model
will be advertising or donations, obtained after the system catches
on, on a large scale, but I have not seen any real attempt to get wide
scale adoption in poor regions. They either do not have the funds or
cannot get critical adoption for this one-way solution. Anyway I would
encourage Amateurs to look at the "technology demonstration" they have
made and consider if similar techniques could be applied to LEO or
Geostationary Amateur or Emergency uses. Assuming they are still
relaying the weekly AMSAT news (I have not seen any actual listing of
what is actually downlinked, except for vague references to tests and
some of Wikipedia) it might be a good fun project, but beware the
technology is very untested and if (or when) they go bust, then the
signals will stop. I have to wonder if the L-band service was a short
term contract, that they can no longer pay for, and that they have
fallen back to cheaper geostationary data.

If someone could set up a receiver (when they actually re-launch/start
a new service) and list what is actually down linked, that would be
good to know, but for now I would consider it still very much in the
testing phase.

I would have thought if they were serious they would have launched a
finished tested solution by now, aimed at developing nations and have
it backed by advertising to make broadcasting self funding.

Dan EI9FHB

On 24/10/2016, Robert Bruninga <bruninga at usna.edu> wrote:
> The Outernet L-band feed is now carrying a condensed version of the AMSAT
> and ARISS weekly news files.  (Global Geosat coverage except for Northern
> Alaska)...
>
> Receivers are simple:  http://aprs.org/outnet.html
>
> For ARISS, I manually added a 2 char grid square to each school listed in
> the school schedule and am asking the outernet folks to parse out that
> location info and plot a 1200 km footprint on their weather globe showing
> where people can tune in the ARISS contacts.  Then their RTL-SDR dongle
> could then actually be retuned to hear the contact.  Just an idea...
>
> Bob, WB4APR
>
> -----Original Message-----
> From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Dani
> EA4GPZ
> Sent: Saturday, October 15, 2016 7:36 AM
> To: amsat-bb at amsat.org
> Subject: Re: [amsat-bb] New Outernet L-Band service...
>
>>> I hope someday a service like this will be available
>>>  from an AMSAT geostationary service.
>
>> I'm pretty confident that the guys at AMSAT-DL are capable
>>  of doing this much better on the upcoming EsHail'2
>> than what Outernet is currently doing on Inmarsat...
>
>> They already have in mind a "DVB-S beacon"...  broadcast
>> from the ground station at Qatar ... carrying videos
>> about Ham radio and Ham radio events on this signal.
>
>> What is more, if you have equipment to operate EsHail'2 on SSB,
>> it's more or less easy to use either the narrowband transponder
>> or the wideband transponder to transmit an Outernet-type signal
>> through EsHail'2, so anyone can have a go with this.
>
>> Outernet uses 4200baud BPSK and half of the bitrate is spent for FEC.
>> You can use a bit less bitrate to get a signal that will even pass
>> through a conventional 2.7kHz SSB filter and you can use less
>> bits for FEC to get increased data throughput (but more SNR required).
>
>> Dani EA4GPZ.
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