III B.TECH I SEMESTER REGULAR EXAMINATIONS November,2010               SETNO:2
DATA COMMUNICATION SYSTEMS 
                                                                    MAX MARKS:80
        ANSWER ANY FIVE QUESTIONS.

1 a)What are the various types of transmission modes and explain.
  b)What are the various types of noise that effect the digital communication? Explain in detail about each of them and techniques to minimize them.

2. Draw the block diagram of optical fiber communication system and explain the each block in detail.
3.a)Explain the process of differential quantizing scheme and compare differential quantizing scheme with direct quantizing scheme.
  b)What are the TDM aspects of T1 carrier systems?
4.a)Define skip distance and derive an expression for skip distance.
  b)Mention different microwave regions & band designations.
5. a)Write about subscriber loop interface circuit.
   b)Compare the functionality of telecommmunication network, electrical communication system and an optical communication system?
6.a)Briefly explain the evaluation of the analog and digital cellular mobile system.
  b)Explain the cellular system with support of GSM?
7. a)Give the algorithm for CRC method of error checking?
   b)Given 1101011011 data frame and generator polynomial G(x) = X^4+X+1. Derive the transmitted frame.
8.a)Discuss the design issues of data link layer?
   b)Explain sliding window protocol?