Telecommunication Networks Second Sessional Paper

Books For Preparation

Q1

( a )

Give short an d to the point answers of the following: Differentiate between a time switch and a space switch. Is a TS switch non-blocking? Justify your answer. What is tropo-scatter communication? In a group of five servers, each is occupied for 15 minutes in an observation interval of 2 hours. Calculate the traffic carried by the group. An exchange is designed to carry 200 calls during the busy hour. One day the number of calls during busy hour is 180. Calculate the grade of service.

10

Q2

( a )

What is a hybrid junction? how does the hybrid junction deteriorate the speech quality? What is the listener's and talker's echo? What are echo cancellers and echo suppressors?

10

Q3

( a )

What is the sky wave mode of communication? Define critical frequency and skip zone. Why are the communication frequencies different for day and night operations in sky wave communication?

10

Q4

( a )

What is line of sight communication? Is the optical horizon same as teh radio horizon? What is fading and how can its effects be reduced?