Cochin University of Science and Techology (CUST) 2008-4th Sem B.Tech Computer Science and Engineering data communication - Question Paper

B.TECH IV SEMESTER exam


DATA COMMUNICATION


1. a) elaborate the advantages of digital transmission?
b) elaborate the most significant transmission impairments?
c) Write note on constellation pattern?
d) define the advantages of biphase coding techniques.
e) Compare ranging from synchronous and asynchronous transmission techniques.
f) What is piggybacking?
g) How is interference avoided by using FDM?
h) What is CDMA?

2. a) define various kinds of noises.
b) Write short notes on 1.channel capacity 2.bandwidth.

OR
3. a) Derive and compare the equations that rule the channel capacity and bandwidth.
b) define various transmission terminologies.

4. a) define various digital signal encoding formats. With the help of neat diagrams
represent the digital data 01001100011.

OR
5. a) define any 2 modulation techniques used in codecs.
b) Short notes on 1. B8ZS 2. HDB3

6. a) elaborate the reasons for breaking a long data transmission up into a number of
frames?
b) List and discuss 3 various ways in which the CRC algorithm can be defined.

OR

7. a) List and briefly define a few of the requirements for effective communication over
a data link.
b) List and define the 3 versions of ARQ.

8. a) Why is a statistical time division multiplexer more efficient than a synchronous time
division multiplexer? Compare them.

OR
9. a) List 3 benefits of spread spectrum.
b) What is frequency hopping spread spectrum?
___________________________________

Earning:   Approval pending.