[aprssig] Open Source/Commercial Use acceptable APRS Alternative?

[Greg Troxel]

"John D. Hays" <john at hays.org> writes:

> There is no mention of a licensing requirement in the protocol
> specification -- https://www.tapr.org/pdf/AX25.2.2.pdf
> A quick patent search reveals a routing patent.
> https://patents.google.com/patent/US4939726A/en but little else.

AX.25 and the modulation schemes for 2m FM and 30m SSB certainly seem
published and implementable without patent licenses.  I see no issues
there. (Plus, it's been about 40 years, more or less.)

My comments about licensing and secret were about LoRa.  When you try to
find out the on-air waveforms, the best reference is reverse engineering
papers.