CORPORATE INSTITITUTE OF SCIENCE & TECHNOLOGY, Bhopal
Important Questions
Voice and Data communication (EC-501)
UNIT-1
1.
1.
Describe local subscriber loop. What do you mean by the term Loop Resistance?
2.
Write down the steps involved in completing a local telephone call.
3.
Explain electronic telephone sets with the help of block diagram.
4.
Briefly explain transmission parameters.
5.
Draw the block diagram of telephone system and explain function of each block in detail.
6.
What is caller identification? How it works?
7.
Explain Crosstalk and its sub types.
8.
Explain call progress tones and signals.
9.
Explain the working of voice frequency circuit arrangements.
10.
Explain cordless telephone system with the help of block diagram.
UNIT-2
11.
What do you mean by the term trunk Circuits? Also explain toll connecting trunks and intertoll trunks.
12.
Explain Operator assisted local exchanges.
13.
Briefly describe common channel signaling system no. 7.
14.
Briefly describe the Telephone Numbering Plan.
15.
Explain telephone switching hierarchy in detail.
16.
What is the difference between local loop and trunk circuits?
17.
What do you mean by the term Exchanges? Explain the working of Digital Exchanges
(Automated Exchanges).
18.
Write short note on toll offices, intertoll trunks and toll connecting trunks.
19.
What is the difference between interoffice trunk and tandem trunk?
20.
List and describe the 3 signaling points of SS7.
UNIT-3
21.
Write short note on Codec & Combo Chips.
22.
What is interleaving? Explain bit and word inter leaving type TDM.
23.
Discuss AT &T’S FDM Hierarchy.
24.
Explain the concept of WDM, its advantages and disadvantages.
25.
Give the difference between synchronous and statistical TDM.
26.
Describe the superframe TDM format and extended superframe format. Why it is used?
27.
What is meant by digital carrier line encoding? What factors must be considered for selecting line encoding format? Explain.
28.
Describe different T-carrier services. Why it is used?
29.
Compare FDM and WDM.
30.
Explain the term quantization. With the help of describe time division multiplexing of
PCM signals.
UNIT-4
31.
Explain the term protocols. What is BPRZ-AMI encoding?
32.
Draw the block diagram of modem and explain it?
33.
What is Shannon capacity theorem? Differentiate between synchronous and asynchronous transmission.
34.
Explain various transmission modes with the help of suitable diagram.
35.
What is topology? Explain different network topologies with the help of neat sketch and advantage and disadvantages of each.

36.
What is line coding? Briefly explain digital to digital encoding.
37.
What is null modem, explain its purpose.
38.
Explain RS232 with electrical mechanical and functional specifications. Compare RS-
232 & RS-449 interface.
39.
Describe serial and parallel transmissions in detail.
40.
Discuss different types of transmission media.
UNIT-5
41.
Explain the redundancy technique for error detection. What are the different redundancy techniques?
42.
Discuss checksum error detection method.
43.
What is hamming distance and how it is useful?
44.
Compare circuit switching, Message switching and packet switching.
45.
Explain cyclic redundancy check codes with the help of block diagram and example.
46.
Explain in detail about the space division and time division switching.
47.
Explain the procedure to find hamming code. Find the hamming code for 10011101010.
48.
What is the difference between message switching and packet switching?
49.
A receiver got a Hamming code of 10100101001 is there any error? If yes, locate the position of the error bit using even parity hamming code. What was the original data?
50.
If the received message is 1010101001 and the generator polynomial is x
3
+x
2
+1. Is it without error?