TELE COMMUNICATION SYSTEMS
UNIT – I- Methods of Communication
PART-A
1. What are Transmission lines? Mention the different types
2. Define antenna.
3. Explain the polarization concept with suitable diagram.
4. What is an omnidirectional antenna?
5. Draw the radiation patterns of broadside array and end fire antennas.
6. Draw the radiation patterns of dipole and Yogi antennas.
7. What is meant by Log-Periodic antenna?
8. Define the terms Bandwidth,Beamwidth, and Polarization related to an antenna.
9. Why are microwave antennas always directional?
10.Write short notes on - Doppler effect
11. A 52 0hm co.axial cable has 36 ohm antenna load calculate SWR.
12. Draw the block diagram of RADAR.
13. What is a RADAR? Give its working principle.
14. Distinguish between balanced & unbalanced wire Transmission Lines.
15. Distinguish between TWTA & Klystron amplifier.
16. Could a voice signal be transmitted without modulation by amplifying the signal
With audio power amplifier and connecting its output to an antenna?Explain.
PART-B
1. Describe briefly radiation mechanism from an antenna.Expalin the evolution of a
dipole for effective radiation.
2. Write any three antennas known to you and briefly discuss their Characteristics
3. Discuss about radio frequency wave propogation methods.Compare their performance.
4. Explain the operation of Reflex Klystron.
5. Write a short notes on Magnetron. (8)
6. Explain the steps in analysing a TWTA.
7. Derive an expression for RADAR range.
8. Draw the block diagram of RADAR and explain its various blocks.Write the Radar
equation.
9. With a neat block diagram exlpain the principle of Pulsed Radar.
10.With a neat block diagram exlpain the principle of CW Dopplar Radar.
11.a) Write short notes on
(i) Transmission Lines and its types
(5)
(ii) Half wave dipole antenna and folded dipole antenna
(5)
(iii) Radio frequency wave propogation
(6)
12. Explain the construction & principle of operation of a two cavity klystron amplifier.
13.With the general block diagram explain the pulsed radar system.
14.With a neat diagram,explain the Yagi antenna.Clearly enumerate the functions of the
element of the antenna.
UNIT II
FUNDAMENTALS OF SATELLITE COMMUNICATIONS
PART-A
1. Define Apogee.
2. What do you mean by Geo-Stationary Orbit?
3. What are the applications of LEO and MEO satellite?
4. Define a transponder.What is its basic function?
5. Draw the block diagram of a satellite transponder.
6. List the applications of satellites in communication.
7. What is station keeping?
8. Define Angle of inclination
9. Define Perigee.
10.What is spin stabilization in satellite?
PART-B
1. Draw the general block diagram of a communication satellite. Explain the
communication and power subsystems.
2. Discuss briefly on the test equipments for earth stations.
3. Explain the receive subsystem of the earth station with necessary
diagrams.
4. Discuss the applications of satellites.
5. Explain in detail about the satellite transponder and its types.
6. Discuss in detail about the Earth station arrangements of a satellite communication
System.
7.Write a brief note on launching a satellite.
8.Explain in detail about the following applications of satellite
Satellite TV, Surveillance, Navigation
9. Explain how kepler’s law and newton’s law’s are used to describe the
Orbit.
10. Explain TTC subsystem.
UNIT III
FUNDAMENTALS OF FIBER OPTIC COMMUNICATION
PART-A
1.
2.
3.
4.
What is total internal reflection?
What is intermodal dispersion? How it can be overcome?
Write brief notes on WDM.
What is step index and graded index fiber. Also explain how light rays propogate
inside a fiber?
5. How can you compare optical communication system with conventional
communication system on basis of bandwidth?
6. State the major two advantages of injection laser diode
over LED’s.
7. Consider wireless light-wave communication.What could be the limiting factors
of such a system?
8. Which is preferred type of fiber for transmitting high data rate information over
long distances?Why?
9. List any four advantages of Fiber-optic cables over conventional
electric cables.
10. Define Attenuation.Give the expression.
PART-B
1. Discuss briefly on the merits and the applications of the optical fiber.
2. Explain, in detail, about light wave transmission.
3. Classify and explain the Fiber optic cable based on index of refraction and mode.
4. List the advantages of optical fiber over copper wire?
5. Sketch and explain the basic elements of an optical communication system.
6. State the four standards commonly followed in optical networks.
7. Discuss the principle by which light is guided along an optical fiber.
8. Explain the reasons for attenuation in optical fibers.
9. Write a brief note on fiber optic data communication systems.
10. Explain the principle and operation of optical transmitters and receivers with
necessary diagrams.
11. Draw the basic block diagram of a Fiber optic communication system and
explain the function of each block.
12. Explain the two most commonly used light sources in fiber optic
communication.
13. Explain the widely used optical receiver in detail.
UNIT – IV-Telephone system and its Applications
PART-A
1. Write the two important technological developments on which the evolution of ISDN
is based.
2. Define telephony.
3. What are primary and basic rates in ISDN?
4. Name the two main digital protocols used in paging systems.
5. Explain the different standard interfaces to connect different subscriber units to the
ISDN
network.
6. What is dotting,Why it is needed?
7. What do you mean by local loop (or) Subscriber loop?
8. Define Paging.
9. What is ISDN?
10. What are the advantages of CDMA over FDMA and TDMA?
11.What is a hybrid used in telephones?
12.What is DTMF?
PART-B
1. Describe the elements of long distance telephony
2. What do you mean by ISDN? Explain its architecture and advantages?
3. Draw and explain the ISDN architecture.
4. Explain the paging transmission and receiving system with suitable
block diagrams
5. Draw the block diagram of modern Facsimile machine and explain.
6. Draw and explain a digital paging receiver.
7. Explain the concepts of ISDN and clearly bringout all the salient features
and its services.
8. Explain the basic functioning of a telephone system.
9. Explain the operation of Paging system.
10.Explain in detail about the ISDN.
11.Expalin the different std. interfaces to connect different subscriber units to the ISDN
network.
12.With a neat block diagram explain the operation of a basic telephone system?
13.Explain the concepts of ISDN and clearly bring out all the salient features and its
services.
UNIT – V- Cellular Radio
PART-A
1. Draw the representation of the spectrum of a telephone system baseband voice
signal.
2. Write the attractive features of CDMA.
3. What is ISM band?
4. State the two important features of cellular system.
5. State the advantages of CDMA based cellular systems.
6. What is the primary function of MTSO in a cellular system?
7. Why GSM uses GMSK modulation technique?
8. State the two frequency ranges used by cordless telephones.
9. Why hexagonal cell’s are normally cellular mobile communication?
10. What arte the advantages of CDMA over FDMA and TDMA?
11. What is Fading?What is its cause?
12. Define Frequency reuse.
13.What is meant by Handoff in cellular system?
PART-B
1. Explain in detail about analog voice transmission.
2. What are the types of frequency hopping?Explain.
3. With the help of block diagram explain a GSM system.What are the advantages of
digital cellular system over their analog counterpart?
4. Explain the forward and reverse channels of IS-95 CDMA systems.
5. Explain the RF channels,time slots and voice transmission aspects of GSM. 6. Discuss
subscriber ID module,privacy and security aspects of GSM.
7. Explain the salient features of IS-95 CDMA PCS in detail.
8. Draw the general block diagram of a cellular radio and explain its operation.
9. Describe the sequence of operations that occur when a person initiates a cellular
telephone call.
10. Explain in detail about Handoff.
11.Explain in detail about spread spectrum techniques.
12. Explain how a call is set up and call terminated in AMPS system.