modem with eight-level signaling element over 3100 Hz line
C = 2* 3100 * log2 (8)
= 6200 * 3
= 18,600 bps
Prof Way Rad, a telecom expert with a proven track record, asks you to invest in his box that can send 10Mbps over a 3100 Hz telephone line. He claims his box achieves this remarkable data throughput because it detects 16 signal levels.