Q1. In a digital system, 8-input links are multiplexed by using STDM. Each of the input sources is making 1024 bits per second. Each frame comprises of 8 bits from each source and adds 1 bit as a framing bit. Calculate the number of frame transmitted per second and the data capacity of the link.
Q2. Calculate the CRC for a 10-bit sequence 1010011110 and a divisor of 1011.
Q3. Describe what is B8ZS encoding? Draw the time versus amplitude graphs for the stream 100100000010001 by using the B8ZS Bipolar encoding scheme.
Q4. Communication line capable of transmitting at a rate of 50 Kbps will be employed to accommodate 10 sessions each producing Poisson traffic at a rate 150 packets/minute. The packet lengths are exponentially distributed with mean 1000 bits. For each session determine the average number of packets in the queue, average number of packets in the system and average delay per packet if line is allocated to the sessions by using the 10 equal-capacity time-division multiplexed channels.
Q5. Distinguish between Go-Back-n and Selective-Reject protocols. Illustrate the sequence numbers for 20 packets in which they are transmitted by using Selective-Reject, if packet 5 is damaged and acknowledgement for packet 12 is lost. Suppose that the sliding window size is 7 and acknowledge for ever packet is sent.
Q6. Provide the header format of ATM Cell. As well describe the semantics of each field in the header.