Why is the response dubious. Remember this isn't a two way system. It is more like broadcast sat TV but for information.
2.4 Ghz is fine for sat downlink (remember one direction only).
For example one sat radio system runs on L brand which is 1 to 2 Ghz.
http://en.wikipedia.org/wiki/WorldSpaceIn the US Sirius XM radio operates at 2.3 Ghz.
http://en.wikipedia.org/wiki/S_band