What you see below is a an honest-to-goodness LoRa carrier that is being received at 11.9024 GHz from SES-2. The total round trip distance from the uplink facility to our 2-cm antenna in Chicago is about 71,572km.
Of course, it's not fair to compare our accomplishments with the exceptional work of Andreas Spiess or the Koppelting project, which both used unmodified LoRa radios for transmitting incredibly long terrestrial distances. Our link budget had a solid bit of help from a 5-meter uplink antenna and 90W amplifier on the satellite. Unlike normal Ku-band satellite terminals, we were using antennas less than a few centimeters across (a cheap, standard LNB with no dish, as well as a custom-made patch antenna/LNB combo; pictures below).
The reason for using a LoRa chip as part of a satellite receiver is due to how well they deal with co-channel interference. With most VSATs, the antenna provides about 36 dBi of gain. Although the gain is important for the link to close, what is just as important is the very narrow beam width of the antenna. As gain increases, the beam width – or view – of the antenna decreases. Satellite tv dishes typically have a beam width of 2-degrees, which means that they don't see all of the other satellites along the geostationary arc that transmit at the same frequency and power level. Our tiny antennas see at least 30-degrees of the sky and have 15 transmitters operating at the same frequency within view. This creates a very noisy environment. Fortunately, our friend LoRa is an expert at dealing with the noise.
Outernet's goal is to create the world's most pervasive information service. There have been two previous iterations of our broadcast data network. The first network (DVB-S over 12GHz), launched in 2014, required a large antenna (60-cm dish) to receive a continuous download at 100kbps, which came to about 1GB of content per day (ebooks, videos, playlists, apps, etc).
Although the download-speed wasn't bad, the antenna was too large and required a high degree of skill to point. We took customer feedback and developed a much more portable data receiver that was far easier to point. In many cases, the antenna could be laid flat on the ground and the receiver download without issue. Unfortunately, the bitrate was excruciatingly slow – 2kbps. And the costs to lease L-band (1.5 GHz) were bone crushing.
We figured there had to be a way to take advantage of the abundance of Ku-band satellite capacity, while maintaining a portable form factor. Our download bitrates will be around 30kbps, which is enough for streaming audio. With just pure file delivery, that would allow for the delivery of 300 MB of content per day. Over time, we'll increase our bitrate to 100kbps, enough for standard definition video streaming (with the right codecs).