Answer 2.9

Sixty-four signalling states can support log264 = 6 bits per symbol. In a baseband channel the maximum signalling rate is equal to twice the available bandwidth. For a 2048 Mbps link, the symbol rate is thus 2048000 / 6 = 341.3 kbaud and the bandwidth required is 341000 / 2 = 170.7 KHz.