Large Numbers Of Gliders

One of the objectives of a radio communication protocol is to minimize the possibilities of “stepping on each other” when many devices transmit messages on the same frequency. Essentially, it attempts to provide each system within “hearing range” to get a “time slot” allocated to them to transmit their information unimpeded. The advantage is obvious for reliability of the communications, but it also implies a limit on the number of “time slots” and therefore on the number of systems that the protocol can stand within each hearing range neighborhood.

The manufacturer has provided the following information: "If too many aircraft are within reach (range) of each other their radio transmissions may attempt to use more bandwidth than what is available. If that happens, all other aircraft will still be received, but with less than the standard 2Hz. This results in a 'graceful degradation' of the system. The exact behavior is off course quite complex (in 3D and with highly uneven antenna gains) but our simulations indicate that there is no degradation with less than 50 aircraft within 'range'. After that, closer aircraft hav a higher probability of being received frequently but you will still get all of them at some point. The RF protocol in v5.00 (due by the end of the year) may have some small improvements to the above."

We will update the information about the details of the number of systems for the US PowerFLARM when the manufacturer will provide the information, likely following the tests and FCC approval of the US powerFLARM, or following possible tests of the RF protocol v5.00 in that respect.