Problem 5 (5 points): DOCSIS 3.0 is a cable modem standard used to provide connectivity to the Internet over cable. Refer to textbook pages 182-185. Assume system with ONE symbol per Hz and 6 MHz channels.

a) What are the range of bit rates provided by the standard on the downstream channels? Specify the needed modulation scheme for these bit rates.

b) How is the bandwidth on the upstream shared by the different subscribers? Explain briefly.

c) Explain briefly what is meant by the ranging process.

Problem 6 (5 points): Suppose that data are transmitted in blocks of sizes 1000 bits. What is the maximum error rate under which error detection and retransmission mechanism (1 parity bit per block) is better than using Hamming code? Assume that bit errors are independent of one another and no bit error occurs during retransmission.