Answer the following problems.
problem 1)a) Describe in detail the ISO-OSI reference model with neat diagram.
b) Describe the reasons for congestion with neat diagram.
c) A large slotted ALOHA system generates 50 requests/sec which includes both originals & retransmissions. A time-slot is 40 msec. Find the
(i) Chance of success in first attempt.
(ii) Probability of success after 5 collisions.
problem 2)a) Find the relationship between m & r. Compute the number of r bits required to correct a given number of data bits m with respect to Hamming code. The code word received is 10011100101. Identify errors if any. Describe a method to detect errors. If any correct it.
b) Compare OSI & TCP reference model with respect to computer networks.
c) Determine the length of 3-byte token for a 16 Mbps token ring LAN. The speed of propagation is 2/3 of velocity of light.
problem 3) Classify routing algorithms in the network layer. Describe with the ex Dijkstra’s algorithm with neat diagram.
b) prepare a note on Ethernets with neat sketches.
c) Twenty four voice signals are to be multiplexed & transmitted over twisted pair. What is the bandwidth required for FDM. Assuming a bandwidth efficiency of 1bit/sec per Hz, what is the bandwidth required for TDM using PCM with neat diagrams.