The channel capacity depends on the amount of noise present, not just the bandwidth. Specifically for a AWGN channel, bits per second <= W*log_2(1+SNR), where

The channel capacity depends on the amount of noise present, not just the bandwidth. Specifically for a AWGN channel, bits per second <= W*log_2(1+SNR), where W is the bandwidth in Hz and SNR is the signal-to-noise ratio. For example, 5 Gbps has been demonstrated using only 100 MHz of bandwidth: http://en.wikipedia.org/wiki/LTE_Advanced http://en.wikipedia.org/wiki/LTE_Advanced