IGNOU MCS-218 - Data Communication and Computer Networks

Q1: What is meant by Modulation? Explain techniques used in digital to analog modulation with the help of a diagram. Q2: (a) What is a Hamming Code? How many redundant bits are required to identify errors in a character of 7 bits. Also mention the specified positions for inserting these redundant bits. (b) Find CRC for the data polynomial X9 + X7 + X4 + X2 + 1 with the generator polynomial X3 + X2 + 1 Q3: Sketch the Manchester and RƵ encoding of the following bit stream: 1011 00 11 01 01 11 Q4: (a) Discuss the key features of random access protocols (multiple access protocols). (b) Draw and explain the vulnerable period for pure Aloha protocol and obtain its throughput expression. Q5: What are the advantages of frame fragmentation in wireless network? Explain. Q6: Explain the implementation of token bucket traffic shaper with the help of a diagram. Q7: Write and apply Bellman Ford Shortest path algorithm to find the shortest paths in a graph given below: Q8: Discuss the QAM (Quadrature Amplitude Modulation) technique. Draw 8-QAM constellation diagram. Q9: (a) What is the utility of a digital certificate? Explain how digital signatures are created? (b) Explain key generation algorithm for RSA with an example. (c) Explain the concept of RPC in detail.