# Why can't we just make all wireless networks use integer multiples of base frequency?

I always wondered why transmission capacity depends on bandwidth. For example, let us say that there is an isolated island. In this island, people decide that all wireless networks use frequencies that are positive integer multiples of one base frequency. Then when we do Fourier transform, we can just use least common multiples of all used frequencies and data in each frequency will exactly be determined except background noises. Or am I wrong here? In this sense, bandwidth seems just to be useless....

• You lost me at "least common multiples". What exactly do you mean?
– jan
Nov 19, 2013 at 2:19
• You'll still have finite capacity to this theoretical communication system because each information-carrying signal requires nonzero bandwidth. Specifically, the Shannon capacity theorem specifies the relationship between information rate, signal-to-noise ratio, and bandwidth that is required for reliable communication. You can coordinate frequency allocation all you want, but you'll still be eventually stymied by the Shannon limit. Nov 19, 2013 at 13:28
• A perfect sinusoid at a pre-determined frequency has zero bits of entropy, and can therefore carry no information. I think that your question needs some more details to explain how you expect to convey any information using this system. Nov 20, 2013 at 0:28