This might be a really trivial question, but I can't wrap my head around it.
In almost every textbook, we're told that bandwidth (among power and noise), is the factor for both range and bitrate. I've been struggeling to find out why.
I'm aware of the Shannon-Hartlet theorem, but I cannot understand why. With this theorem, the capacity is equal for me transmitting data on a channel from 115-120 MHz and 1150-1155 MHz, since the bandwith is both 5MHz. Why? Am I misunderstanding the term bandwith? Is it because I fx. send my bits on relative 1, 2, 3, 4 and 5 MHz of the bandwith?
And why does the frequency not have any influence? Let's assume I can encode 2 bits into every symbol, wouldn't I be able to transmit 10 times the amount of bits per second on the higher frequency rather than the low frequency, since I have 10 times the oscilations?
I hope somebody can help me understand why bandwidth is so important, and frequency is not.