Originally Posted by
cribbagepeg
Would a satcom person please step in? The raw bandwidth of a sat link is misleading. Individual A/C must either be polled (asked to transmit) or must speak up in the hope that data can be communicated. Simultaneous asychronous speakups - "collisions" - jam things up and the various originators must be separated in time, so they all get their data packets through. Because of transit time to/from the satellite(s), there is considerable latency involved, and at peak traffic times, actual throughput can be reduced to a fraction of the raw capacity of the sat channel. A small fraction.
This was covered extensively in the AF447 saga, and should be summarized here and "stickified" to reduce misconceptions. At least for the few that will read it before posing novice questions or "solutions".
Since the AF447 incident SATCOM capabilities have hugely improved. INMARSAT is providing far higher bandwidths from its new geostationary satellites as they have different antennas with smaller footprints within the overall geostationary footprint some of then steerable. INMARSAT is now offering 'mobile ISDN' at speeds from 64 to 128Kbit
Iridium is launching a new series of low earth orbit satellites (Iridium Next). Iridium satellites are rather like orbiting cell phone base stations and users have a 'connection oriented' datalink to the satellites. Again the data rates have been increased by orders of magnitude. Iridium already sells a system called SkyTrac that does much of the flight following task being discussed here.
With communications things are changing extremely fast.