The complete channel bandwidth.
Bandwidth is a fixed quantity, so it cannot be changed. Hence, the channel capacity is directly proportional to the power of the signal, as SNR = (Power of signal) / (power of noise). so for example a signal-to-noise ratio of 1000 is commonly expressed as: 10 * log10(1000) = 30 dB.
Capacity = bandwidth * log2(1 + SNR)
Output1 : C = 30000 * log2(1 + SNR) = 30000 * 11.62 = 348600 bps