[AR] Re: Aw: Re: Future Exploration Policy (was Re: Re: Congrats SpaceX
- From: Norman Yarvin <yarvin@xxxxxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Fri, 9 Feb 2018 18:11:16 -0500
On Fri, Feb 09, 2018 at 02:15:41PM -0700, Paul Mueller wrote:
I'm no EE (it's all magic to me), but I was thinking about things like
frequency hopping, used for lots of transmitters and receivers in close
proximity (e.g. RC aircraft). Maybe that's not an option for going 22,000
miles with one end that's very difficult to service--I could be totally up
in the night. But I also figure those EEs are pretty clever and have all
kinds of tricks up their sleeves.
Not the kind of tricks that violate Shannon's Law, we don't.
Frequency hopping and such can't increase the data rate that can be
transmitted over a given bandwidth. And the bandwidth slots that are
allocated to satellites are fixed by national laws and international
agreements.
The reason why frequency hopping works with RC aircraft (when it does
work) is that there is enough bandwidth available for everybody, and
all that needs to be avoided is accidental use of the same channel by
two different aircraft.
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