JNTU B.Tech II Semester Examinations, TELECOMMUNICATION SWITCHING SYSTEMS AND NETWORKS, Apr/May 2008
( Common to Electronics & Communication Engineering and Electronics &
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
1. (a) Compare the features of single stage and multistage switching network configurations?
(b) A fully connected network supports full duplex communication using unidirectional links. Show that the total number of links in such a network with n nodes, is given by 2×nC2. [8+8]
2. (a) Define each of the following terms: program, procedure, processor, process,
user, task, job and subroutine.
(b) Find the blocking probability of a three stage network for M=N=2048,p=q=16
and ? = 0.1 for S= 16, 24 and 32. [8+8]
3. (a) What are the major components of telecommunication network? Explain in
detail about subscriber loop systems.
(b) An exchange uses a -40 V battery to derive subscriber lines. A resistance of 250 is placed in series with the battery to protect it from short circuits. The subscribers are required to use a standard telephone set which offers a d.c. resistance of 50. The microphone requires 23mA for proper functioning. Determine the farthest distance from the exchange at which a subscriber can be located if 26 AWG conductor is used. [8+8]
4. (a) What are the different types of busy hours defined by CCITT? Explain.
(b) In a group of 10 servers, each is occupied for 30 minutes in an observation
interval of two hours. Calculate the traffic carried by the group. [8+8]
5. (a) Explain the functions and features of data communication network components.
(b) Discuss peer to peer client / server networks. [8+8]
6. (a) Compare and contrast standard Ethernet, Fast Ethernet and Gigabit Ethernet.
(b) What is looping problem in transparent Bridges? How is it avoided using spanning tree algorithm [8+8]
7. (a) Compare HDLC and LAPD protocols.
(b) Describe ISDN, functional architecture and standards of ISDN Channels. [6+10]
8. (a) Explain the operation of cable modem
(b) Discuss features of HFC Networks. [8+8]