Rajiv Gandhi Proudyogiki Vishwavidyalaya 2010-5th Sem B.E Computer Science and Engineering .(ester) ,e, DATA COMMUNICATION - Question Paper

B.E. (Fifth Semester) EXAMINATION, June, 2010

(Computer Science & Engg. Branch)

DATA COMMUNICATION

 

Note : Attempt any five questions.

1.   (a) Explain the basic components of data communication and their characteristics. [Mark :10]

(b) Write a brief note on Serial and Parallel transmission giving suitable example. [Mark:10]

 

2.   (a) Describe the concept of switching and contrast circuit switching and packet switching. [Mark:10]

(b) Explain in brief the operation of Time Division Multiplexing. [Mark:05]

(c) What signal-to-noise ratio is needed to put a T1 carrier on 50 kHz line ? [Mark:05]

 

3.   (a) Suppose that x bits of user data are to be transmitted over a K-hop path in a packet switched networks as a series of packets, each containing P data bits and h header bits, with x>p+h. The bit rate of the lines is bbps and propogation delay is negligible. What value of P minimizes the total delay ?[Mark:10]

(b) Explain QAM modulator in brief. [Mark:05]

(c) Write a brief note on Nyquist theorem.[Mark:05]

 

4.   (a)Describe the functioning of Null Modem. [Mark:10]

(b) What is bridge ? Describe how two LANs following two different protocols can be connected using a bridge. [Mark:10]

 

5.   (a)What is ISDN ? Explain in detail. [Mark:10]

(b) Explain the following components of baseband LANS : [1] Network Interface Card, [2] Repeaters [Mark:10]

 

6.   (a) Explain the different types of Guided Media with example. [Mark:10]

(b) Explain the charecteristics of transmission line. [Mark:10]

 

7.   (a)Describe the various error detection methods. [Mark:10]

(b) assume the CRC generator polynomial of x5 + x4 + x2 +1 is usedto provide error checking. Compute the bit stream that will be transmitted if a message 111000111000 is sent. [Mark:10]

 

8.   Write short notes on any two of the following

(a)           Network topology

(b)          Fax modems

(c)           Data compression devices

(d)          Hamming code

(e)           Transmission media. [Mark:10 each]