Download AKTU B-Tech 7th Sem 2016-2017 NEC 702 B Data Communication Networks Question Paper

Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 7th Semester (Seventh Semester) 2016-2017 NEC 702 B Data Communication Networks Question Paper

Printed Pages: 4 i ' NEC- -702(B)
I(Following Paper ID and Roll No. to be ?lled In your
Paper ll):
Answer Books)
.
229006] Roll No.
Regular-
B.TECH
Theory Examination(0dd Sem-VII), 2016-17
DATA COMMUNICATION NETWORKS .
T ime : 3 Hours Max. Marks. ? 100
Note : Attempt all Sections. If require any missing data; then
choose suitably.
SECTION -A
1. Attempt all question in brief. (lOXZ=20)
a.
What do you mean by transmission system
utilization?
In which layer and why error detection and
correction are required?
An ALOHA network uses 19.2 Kbps channel for
sending message packets of 100 bit long size.
Calculate the maximum through put for pure
ALOHAnetwork.
What is Hamming code?
What is gigabit Ethernet?
_ Write the advantage of carrier sense multiple access
protocol.
702(B)/12/2016/7860 (1) [P.T.O.

2. Attempt any three of the following:
a.
NEC- 702(B)
What IS limited? contention p10tocol?7
Explain wavelength division multiple access
protocol.
What is meaning of 1 00 BASE?T. Explain each tenn.
A channel has a bit rate 4kbps and propagation delay
of 20 msec. What will be the size of frame range
stop and Wait give an 50 percent.
SECTION - B
(3x10=30)
Draw the block diagram of a communication model.
Explain each bock 1n detail.
What is modulation? Why modulation is needed?
Differentiate between Amplitude modulation,
frequency modulation and phase modulation.
Con'sider' an irregular LDPC code with
A(x) = 0.3x2 + 0.1x3 +0.6x4 and p(X) a117+bx8 (i) Find
a and b such that the code has rate 1/2. Use these
values for the remaining parts of the problem. (ii)
What fraction of thevariable nodes has degree 4?
(iii) What fraction of the check nodes have degree
9? (iv) Find the Eb/NO threshold for belief
propagation over an AWGN channel using the
Gaussian approximation.
What is HDLC? Discuss various type of
con?guration model in HDLC used by station.
702(B)/l 2/2016/7860 (2)
e.
Attempt any one of the following :
NEC-702(B)
Explain static channel allocation and dynamic
channel allocation in detail.
SECTION - C
(l><10=10)
a. What is multiple access technique? Explain ?FDMA
and TDMA access technique in detail.
b. Prove .that link budget equation
PRXdBm+GTXdB+GRXdB_L pa alth(R) Where L patth(R) is
path loss.
Attempt any one of the following : (1 x 10=10)
a.
' Attempt any one of the following:
a.
What is noise? What are various form and source
of noise? Discuss the various form and source of
nosie? Discuss the importance of S/N ratio in radio
receiver.
Explain with proper ?gure deterministic and
stochastic signal. Where and how signal is more
affected from noise?
(1x10=10)
Explain orthogonal ?'equency division multiplexing.
Draw and explain the block diagram of OFDM
transmitter and receiver. Where OFDM is used?
Explain the CRC error detection technique
generator polynomial x4+x3+1 and data is
11100011. I
702(B)/12/2016/7860 (a) [P.T.O.

NEC-702(B)
6. Attempt any one of the following .: (1><10=10)
a.
Explain working of point to point protocol. Discuss
frame format for point to point protocol.
An AWGN channel of bandwidth 3MHz are given.
Assume that implementation constraints dictate an
excess bandwidth of 50%. Find the achievable bit
rate, the Eb/No required for a BER of 10?8 and the
receiver sensitivity (assuming a receiver noise
?gure of 7dB) for the following modulation scheme
assuming that the bit-to symbol map is Optimized
to minimize the BER whenever possible (i) QPSK "
(ii) 8-PSK. '
7. ? Attempt any one of the following : ' (1X 10=10)
a.
How do we say collision detection is analog process?
Why do we prefer CSMA over ALOHA? Prove that
maximum efficiency of ALOHA IS l/e. -
Prove that the throughput of network using slotted
ALOHA can be given as S=GeG where G is the load
and S is throughput. .
702(B)/12/2016/7860 (4)