EC6004 Satellite Communication

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VEC/BE/ECE/QB/VII/EC6004/SAT COMM/2016-2017/ODD

VEC/BE/ECE/QB/VII/EC6004/SAT COMM/2016-2017/ODD SEM SEM -- Prepared by Prepared by S.Marirajan, S.Marirajan, A.P.(Sr.G) A.P.(Sr.G) Page Page 22

EC6004 SATALLITE

EC6004 SATALLITE COMMUNICATION

COMMUNICATION

UNIT

UNIT I I SATELLITE SATELLITE ORBITSORBITS

Kepler’s Laws, Newton’s law, orbital parameters, orbital perturbations, station keeping, Kepler’s Laws, Newton’s law, orbital parameters, orbital perturbations, station keeping, geo stationary and non Geo-stationary orbits–Look Angle Determination- Limits of visibility – geo stationary and non Geo-stationary orbits–Look Angle Determination- Limits of visibility – eclipse-Subsatellite point–Sun transit outage-Launching Procedures-launch vehicles and eclipse-Subsatellite point–Sun transit outage-Launching Procedures-launch vehicles and propulsion. propulsion. PART A PART A Q. Q. No No Questions Questions BTBT Level Level Competence Competence 1.

1. State Kepler’s second law.State Kepler’s second law. _BTL1_BTL1 _Remember_Remember 2.

2. Summarize ascending node & descending node.Summarize ascending node & descending node. _BTL6_BTL6 _Create_Create 3.

3. Illustrate the orbital parameters used for positioning aIllustrate the orbital parameters used for positioning a satellite.

satellite. BTL2 BTL2 UnderstandUnderstand 4.

4. Summarize the satellite visibility criteria.Summarize the satellite visibility criteria. _BTL3_BTL3 _Apply_Apply 5.

5. Analyze where the determination of antenna look anglesAnalyze where the determination of antenna look angles used?

used? BTL4 BTL4 AnalyzeAnalyze 6.

6. Identify the purpose of Station keeping.Identify the purpose of Station keeping. _BTL3_BTL3 _Apply_Apply 7.

7. List the basic factors affecting satellite position.List the basic factors affecting satellite position. _BTL4_BTL4 _Analyze_Analyze 8.

8. On what factors the limits of visibility depends? ConsideringOn what factors the limits of visibility depends? Considering an earth station at the equator, with the antenna pointing an earth station at the equator, with the antenna pointing either west or east along the horizontal evaluate the limiting either west or east along the horizontal evaluate the limiting angle.

angle.

BTL5 Evaluate BTL5 Evaluate

9.

9. Define geostationary orbit.Define geostationary orbit. _BTL1_BTL1 _Remember_Remember 10.

10. What What do do you you mean mean by by apogee? apogee? BTL1 BTL1 RememberRemember 11.

11. Compare between ascending node and Compare between ascending node and descending node.descending node. _BTL2_BTL2 _Understand_Understand 12.

12. Justify why the orbit is called as orbital Keplerian element?Justify why the orbit is called as orbital Keplerian element? _BTL5_BTL5 _Evaluate_Evaluate 13.

13. Summarize the Newton’s laws.Summarize the Newton’s laws. _BTL2_BTL2 _Understand_Understand 14.

14. Define the Kepler’s First law for Define the Kepler’s First law for planetary motion.planetary motion. _BTL1_BTL1 _Remember_Remember

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15. Develop few frequency bands used for satellite applications. _BTL3 _Apply 16. Differentiate Apogee and Perigee. _BTL4 _Analyze 17. What are Geostationary Satellites? _BTL1 _Remember 18. Generate the term azimuth angle. BTL6 Create 19. Summarize the sub satellite point and what is its

significance? BTL1 Remember 20. Outline the sun transit outage. _BTL2 _Understand

PART – B

1. (i)Express the three Kepler’s laws of planetary motion and list the various orbital parameters. (8)

(ii)Estimate the suitable equations for look angles and the range for geostationary satellite. (8)

BTL2 Understand 2. (i)List and explain any one type of launching procedures of

satellite. (8)

(ii) A satellite in polar orbit has a perigee height of 600km and an apogee height of 1200km. Show the mean motion and the rate of regression of the nodes. Assume the polar radius of the earth to be equal to 6357kms. (8)

BTL1 Remember

3. (i)Justify how altitude and orbit control is achieved from an earth station? (8)

(ii) Explain about the orbital parameters in detail. (8)

BTL6 Create 4. (i)Examine the orbital perturbations in detail. (12)

(ii) A satellite is orbiting in the equatorial plane with a period from perigee to perigee of 12 h. Given that the eccentricity is 0.002. Calculate the semi major axis. The earth’s equatorial radius is 6378.1414km. (4)

BTL4 Analyze

5. (i)Show the different types of satellite orbits and discuss their merits and demerits. (8)

(ii)If a satellite is at a height of 36000km and orbiting in equatorial plane, comment whether the satellite will be under eclipse on equinox days and discover the duration of the eclipse. (8)

BTL3 Apply

6. (i)Generate from basic principles the orbital velocity of a satellite. (8)

(ii)Formulate the orbital velocity for the circular orbit. (8)

BTL5 Evaluate

7. (i)What are the basic terms for earth-orbiting satellites and explain. (8)

(ii) Describe briefly the earth eclipse of satellite. (8)

BTL1 Remember 8. (i)Infer what you had understand by the sub satellite point? (8)

(ii)Summarize on launch vehicles and propulsion. (8) BTL2 Understand

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9. (i) Describe the significance of station keeping. (8)

(ii)Define the term angle of tilt and explain how the polar mount antenna works? (8)

BTL1 Remember 10. (i) Categorize the frequency allocations and draw the

frequency spectrum for satellite services. (12) (ii)Illustrate the effects of non-spherical earth. (4)

BTL4 Analyze 11. (i)Discuss in detail about the orbital maueuvers like

inclination, ascending node, semimajor axis and eccentricity. (8)

(ii)Explain about orbital elements. (8)

BTL2 Understand 12. (i)Show the different applications & different services

provided by satellite services. (6)

(ii) Develop the points to predict the satellite position. (10)

BTL3 Apply 13. (i)Can you give a short notes on atmospheric drag and

inclined orbits. (12)

(ii)List the features of near stationary orbits. (4)

BTL1 Remember 14. (i) Identify the limits of visibility for an earth station situated

at mean sea level, at latitude 48.42o north and longitude 89.26o west. Assume a minimum angle of elevation of 5o. (6)

(ii)Examine the Newton’s laws. (6)

(iii)Analyze the conditions that are required for an orbit to be geostationary. (4)

BTL4 Analyze

UNIT II SPACE SEGMENT AND SATELLITE LINK DESIGN

Spacecraft Technology- Structure, Primary power, Attitude and Orbit control, Thermal control and Propulsion, communication Payload and supporting subsystems, Telemetry, Tracking and command. Satellite uplink and downlink Analysis and Design, link budget, E/N calculation- performance impairments-system noise, inter modulation and interference, Propagation Characteristics and Frequency considerations- System reliability and design lifetime.

PART A

Q.No Questions BT

Level

Competence 1. Analyze the reason of omnidirectional antenna being used _BTL4 _Analyze

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aboard a satellite for telemetry and command during the launch phase.

2. Explain the essential of thermal control segment for a

spacecraft. BTL2 Understand 3. Define the term “EIRP”. _BTL1 _Remember 4. _{What is spin body stabilization?}

BTL5 Evaluate 5. Define frequency planning. BTL1 Remember 6. Infer the reason of intermodulation noise originate in a

satellite link. BTL2 Understand 7. Outline the meaning of antenna noise temperature and system

noise temperature referred to the input. BTL1 Remember 8. Justify how the attitude of a satellite controlled through

active control? BTL6 Create 9. Examine why noise temperature is a useful concept in

communication receivers? BTL4 Analyze 10. Identify the parameters that decide the system reliability. _BTL1 _Remember 11. Write the command systems to protect against unauthorized

commands and errors. BTL5 Evaluate 12. Draw some common structural types to hold the spacecraft. _BTL1 _Remember 13. Point out the two segments of basic satellite communication. _BTL4 _Analyze 14. Write a note station keeping. _BTL3 _Apply 15. Define the term propellant. _BTL1 _Remember 16. Write the concepts of frequency reuse. _BTL3 _Apply 17. Illustrate how do you achieve stabilization by momentum

wheel? BTL2 Understand

18. Demonstrate sky noise. _BTL3 _Apply 19. Summarize the features of spot beam antenna. BTL2 Understand 20. Formulate uplink & downlink equation of a satellite access. _BTL6 _Create

PART – B

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1. (i)Consider a transmit earth station operating at an uplink frequency of 6GHz. The antenna diameter is 7m with an efficiency of 60%. The antenna tracking loss and atmospheric attenuation is 1.2dB. The uplink slant range is 37506km. Identify the required output power (dBW) of the HPA system at the antennna feed to provide a -80 dBW/m2 power flux density at the satellite. (8)

(ii)Discuss in detail about the communication payload and supporting subsystems. (8)

BTL6 Create

2. (i)For a satellite circuit the carrier-to-ratios are uplink 23dB, downlink 20dB, and intermodulation 24dB. Calculate the overall carrier-to-ratio to decibels. Suggest a method to reduce intermodulation noise. (8)

(ii)Examine the system reliability and design life time of the space segment. (8)

BTL4 Analyze

3. (i)Demonstrate the concept of frequency planning & explain the frequency considerations. (6)

(ii)Sketch the attitude control momentum wheel stabilization in the space segment with necessary diagrams and explain it. (10)

BTL3 Apply

4. (i)Describe about antenna subsystem. (10)

(ii)Discuss in detail about the spacecraft subsystem. (6) BTL2 Understand 5. (i)Generate the various supporting subsystems and its

structure with diagrams.(4)

(ii)Design the equations for primary power of subsystems. (12)

BTL5 Evaluate

6. (i)Recall the important points about the propulsion. (10) (ii) Define propagation characteristics. (3)

(iii)Write short note on performance impairments of interference. (3)

BTL1 Remember 7. Examine how the attitude and orbit control system (AOCS) is

achieved through spin stabilization systems? Give necessary diagrams. (16)

BTL4 Analyze 8. (i)Explain TT and C system in detail. (8)

(ii)Express equation for the downlink C/N ratio for the satellite. (8)

BTL2 Understand 9. (i)State how intermodulation noise originates in a satellite link

and describe how it is reduced? (8)

(ii)Find the equations for the link power budget. (8)

BTL1 Remember 10. (i)State the importance of station keeping. (8)

(ii)Derive the satellite link design equation. (8) BTL1 Remember 11. (i)Summarize the sources of noise in satellite communication. BTL2 Understand

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What is the importance of noise temperature in link design? (8)

(ii)Explain the necessity of power amplifier in the transponder. (8)

12. (i)Describe briefly the factors governing the design of satellite links. (10)

(ii)Outline the factors that contributing to noise in an earth station receiving channel. (6)

BTL1 Remember 13. (i)Justify the reasons behind why the transponders are

connected in the communication channel with a neat diagrams. (4)

(ii)Analyze the wideband receiver and input demultiplexer with appropriate diagrams. (12)

BTL4 Analyze

14. Solve C/N ratio is directly proportional to G/T ratio from the

calculation of system noise temperature. (16) BTL3 Apply UNIT III EARTH SEGMENT

Introduction – Receive – Only home TV systems – Outdoor unit – Indoor unit for analog (FM) TV – Master antenna TV system – Community antenna TV system – Transmit – Receive earth stations – Problems – Equivalent isotropic radiated power – Transmission losses – Free-space transmission – Feeder losses – Antenna misalignment losses – Fixed atmospheric and ionospheric losses – Link power budget equation – System noise – Antenna noise – Amplifier noise temperature – Amplifiers in cascade – Noise factor – Noise temperature of absorptive networks – Overall system noise temperature – Carrier-to- Noise ratio – Uplink – Saturation flux density – Input back off – The earth station - HPA – Downlink – Output back off – Satellite TWTA output – Effects of rain – Uplink rain– Fade margin – Downlink rain – Fade margin – Combined uplink and downlink C/N ratio – Intermodulation noise.

PART A

Q.No Questions BT Level Competence 1. State the reason for the high power amplifier in earth stations

deploying some sort of redundancy configuration. BTL5 Evaluate 2. Analyze the basic form of a cassegrain antenna. _BTL4 _Analyze 3. Write the features of MATV.

BTL1 Remember 4. Identify the parameter which is generally regarded as figure _BTL4 _Analyze

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of merit. Why?

5. Define antenna gain. BTL1 Remember 6. A satellite downlink at 10GHz operates with a transmit

power of 5w and an antenna gain of 48.2dB. Estimate the EIRP in dBW.

BTL6 Create

7. For a given satellite and signal transmission show the earth

station parameters affecting the C/N ratio. BTL3 Apply 8. What is meant by noise factor and noise margin? BTL2 Understand 9. What do you understand by the term Saturation flux density? BTL1 Remember 10. Give the reason for deploying a demodulator / remodulator

unit in our home television set when we want to function in a satellite TV / FM receiving system.

BTL5 Evaluate

11. Indicate the reason of LNA in a satellite receiving system

placed at the antenna end of the feeder cable. BTL2 Understand 12. Outline, why cassegrain antennas are popular for large earth

stations? BTL1 Remember

13. What is meant by earth segment? BTL2 Understand 14. Compare KU-band and the C-band receive only systems. BTL6 Create 15. Sketch the outdoor unit for receive only home TV systems. _BTL3 _Apply 16. State the different transmission losses during the transmission

link. BTL1 Remember

17. Write about fade margin. _BTL3 _Apply 18. Draw and explain antenna misalignment losses. _BTL1 _Remember 19. What do you infer about intermodulation? _BTL2 _Understand 20. Calculate output back-off in downlink process. BTL4 Analyze

PART – B

1.

Draw a neat block diagram and explain the functional elements of a basic digital earth station and also the main elements of a satellite tracking system. (16)

BTL1 Remember

2.

Elaborate the procedures involved in test equipment

measurements on G / T, C / N_O and EIRP with reference to the BTL6 Create

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earth segment. (16) 3.

(i)Describe briefly MATV & CATV systems. (8)

(ii)Explain how the gain of large antennas can be optimized. (8)

BTL1 Remember

4.

(i)Estimate Equivalent Isotropic radiated power with an example.(6)

(ii)Discuss in detail about the various transmission losses. (10)

BTL2 Understand

5.

(i)Point out the calculation of link power budget equation. (4) (ii) Identify the various types of system noise. Explain it in detail. (12)

BTL4 Analyze

6.

(i)Compute the equation caused by various factors for Uplink communication. (8)

(ii) Explain how the satellites are inter linked without need for intermediate ground stations? (8)

BTL3 Apply

7.

(i)Explain the operation of Horn antenna and reflector antenna used for satellite communication. (10)

(ii)Discuss how fade margin occur during uplink communication. (6)

BTL2 Understand

8.

(i)Describe briefly which antenna is suitable for earth station by its characteristics. (8)

(ii) Summarize the concepts and operation of HPA & LPA in satellite communication. (8)

BTL1 Remember

9. (i)Examine about terrestrial interface with suitable diagrams. (10)

(ii) Compare MATV & CATV. (6)

BTL4 Analyze 10 (i)Sketch the block diagram and explain the TVRO system.

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(ii)Show any one test equipment for the measurement on carrier-to-ratio. (8)

BTL3 Apply

11

(i)Explain how the TWTA is used in satellite communication with a neat diagrams.(12)

(ii)Formulate the expression for downlink fade margin. (4)

BTL5

Evaluate

12

(i)Derive the expression of output back-off, satellite TWTA output for the downlink communication. (8)

(ii)Write a short notes on

a) polarization interleaving (4) b) absorptive network (4)

BTL2 Understand

13

(i)Calculate the carrier-to-ratio for the combined uplink and downlink communication. (8)

(ii)Analyze the type of noise occur when multiple carriers pass

BTL4 Analyze

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through in any device with nonlinear characteristics and explain it. (8)

14

(i)Outline the points that how the satellite communication are getting disturbed by the effect of rain. (8)

(ii) List the features of cassegrain antenna with suitable diagrams. (8)

BTL1 Remember

UNIT IV SATELLITE ACCESS

Modulation and Multiplexing: Voice, Data, Video, Analog – digital transmission system, Digital video Broadcast, multiple access: FDMA, TDMA, CDMA, Assignment Methods, Spread Spectrum communication, compression – encryption.

PART A Q.

No

Questions BT Level Competence 1. Distinguish centrally controlled random access for satellite

access from distributed control random access. BTL4 Analyze 2. Television transmission may be classified as full-transponder

or half-transponder transmission. State what this means in terms of transponder access.

BTL3 Apply 3.

Determine the limitations of CDMA. BTL5 Evaluate 4. How does the spread spectrum system differ from

conventional communication system? BTL1 Remember 5. Compare single access and multiple access. BTL2 Understand 6. List the advantages of TDMA over FDMA. BTL1 Remember 7. Define multiplexing. BTL1 Remember 8. Write the two basic problems in satellite digital transmission. BTL2 Understand 9. When VSAT type terminals involved CDMA offers several

advantages of satellite networking. What are they? BTL1 Remember 10. Evaluate the methods of multiple access techniques for

satellites. BTL5 Evaluate 11. Distinguish preassigned and demand assigned traffic. BTL2 Understand 12. Calculate the guard time of TDMA. BTL3 Apply 13. State Carson’s rule. BTL1 Remember 14. Estimate the frame efficiency of TDMA. BTL6 Create 15. Express the processing gain of a satellite access. _BTL2 _Understand 16. Analyze the digital speech interpolation. _BTL4 _Analyze

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17. Summarize the important feature of Intelsat SCPC system. BTL6 Create 18. Identify the limitations of FDMA satellite access. _BTL1 _Remember 19. Point out the pre-assigned TDMA satellite access. _BTL4 _Analyze 20. Derive the equation of BER for PSK modulation. BTL3 Apply

PART – B

1.

(i) Describe the diagrammatic representation of a SPADE communication system and explain how this is used on Intelsat satellites. (8)

(ii) Outline the “frequency reuse” process and give the merits of spread spectrum communication. (8)

BTL1 Remember

2. Illustrate the features of various multiple access schemes

deployed for satellite access and compare it. (16) BTL3 Apply 3.

(i) Show the operation of FDMA and list how this differs from FDM. (6)

(ii)What are the ways in which demand assignment may be carried out in FDMA network and explain it. (10)

BTL1 Remember

4.

Point out the comment on pros and cons of satellite system based on TDMA. Also explain the TDMA frame format in

detail with relevant diagrams. (16)

BTL4 Analyze

5.

(i) Express FDMA in detail and also enumerate the interference in FDMA. (8)

(ii) Explain direct sequence spread spectrum communication in detail. (8)

BTL2 Understand

6.

(i) Demonstrate back off meaning and why is it necessary in multiple access systems. (6)

(ii)Show the digital video broadcasting operation in detail. (10)

BTL3 Apply

7.

(i) Develop the schemes for compression and encryption are implemented in satellite communication. (6)

(ii) Explain in detail about the preassigned FDMA with necessary diagrams. (10)

BTL5 Evaluate

8.

(i)State the reasons behind the wide acceptance of digital transmission systems. (6)

(ii) Summarize the digital transmission of ADM & ADPCM techniques. (10)

BTL1 Remember 9. Discuss about analog voice transmission. (16) BTL2 Understand 10. Illustrate in detail about pre assigned & demand assigned

TDMA. (16) BTL4 Analyze

11.

Explain the principle behind the spectrum spreading and dispreading and how this is used to minimize interference in a CDMA system. (16)

BTL2 Understand

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12.

(i)Discriminate the operation of ON board signal processing for FDMA / TDMA operation with suitable diagrams. (10)

(ii) Outline the techniques of PCM CODEC. (6)

BTL4 Analyze

13.

(i) Estimate the pre-assigned traffic for FDMA. (6)

(ii) Summarize the important feature of Intelsat SCPC system. (10)

BTL6 Create

14.

(i)Identify the bandlimited and power limited TWT amplifier operation. (10)

(ii) Explain the operation of digital TASI in TDMA operation. (6)

BTL1 Remember

UNIT V SATELLITE APPLICATIONS

INTELSAT Series, INSAT, VSAT, Mobile satellite services: GSM, GPS, INMARSAT, LEO, MEO, Satellite Navigational System. Direct Broadcast satellites (DBS)- Direct to home Broadcast (DTH), Digital audio broadcast (DAB)- World space services, Business TV(BTV), GRAMSAT, Specialized services – E –mail, Video conferencing, Internet.

PART A

Q. No Questions BT Level Competence 1. What is the principle behind DTH & GPS? BTL1 Remember 2. Discuss an intelligent VSAT must use what type of networking

to permit the maximum utilization of the satellite capacity? BTL2 Understand 3. Write the applications supported by INTELSAT & INSAT

series. BTL1 Remember

4. Give the main idea of World space receivers. BTL2 Understand 5. Choose the services provided by GSM. BTL1 Remember 6. _{Evaluate the features of LEO.} BTL 5 Evaluate 7. What do you infer about GRAMSAT? BTL2 Understand 8. _{Classify the two areas of satellite communications which are}

gaining major thrust from leading satellite industries and

organizations in recent years. BTL 4 Analyze 9. Justify when there is available bandwidth of 500MHz and how

many transponder each of bandwidth 24MHz can be accommodated.

BTL6 Create

10. State congestion and slowstart with reference to Internet traffic. BTL1 Remember 11. Indicate the services rendered by DTH. BTL2 Understand 12. Identify how the satellite used for video conferencing? BTL1 Remember

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13. _{Categorize the types of satellite services.} BTL 5 Evaluate 14. _{Point out the satellite mobile services.} BTL 4 Analyze 15. Demonstrate the different types of applications for satellite

systems. BTL3 Apply

16. Outline the three regions to allocate the frequency for satellite services.

BTL 4 Analyze 17. Illustrate the functions of DBS. BTL3 Apply 18. _{Summarize the regions covered by INMARSAT.} BTL6 Create 19. Define BTV. BTL1 Remember 20. Identify the concept of DAB. BTL3 Apply

PART – B 1.

Describe briefly the types of INTELSAT satellites with respect to basic space craft characteristics and vehicle types. (16)

BTL1 Remember

2.

(i) Distinguish the block diagram of an indoor & outdoor unit for a DBS home receiver. (8)

(ii) Analyze the DTH system with the help of neat block diagrams. (8)

BTL 4 Analyze

3. Discuss how GSM & GPS deploying satellites have improved

the mobility of the customers. (16) BTL2 Understand 4.

Identify how the specialized services like video conferencing, e-mail and internet have revolutionized the present day communication scenario along with their working principle respectively. (16)

BTL1 Remember

5.

(i)Identify how DTH operation is carried out with a neat diagrams. (8)

(ii)Point out some recently launched satellites by ISRO. (8)

BTL 4 Analyze

6.

Illustrate elaborately on the various mobile satellite services, its associated challenges and its impact on services, when delivered by satellites. (16)

BTL3 Apply

7.

(i) Extend the operation of GPS in detail with necessary diagrams. (8)

(ii) Review the concepts of VSAT system in detail with neat diagrams. (8) BTL2 Understand 8. Discuss about (i) INTELSAT (4) (ii) E-mail (4) (iii) BTV (4) (iv) DTH (4) BTL3 Apply

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9.

(i) Explain about (a)INMARSAT (8) (b) GRAMSAT. (8)

BTL2 Understand 10. Summarize the details about INSAT. (16) BTL1 Remember 11. Elaborate the main features and services offered by mobile

satellite systems. (16)

BTL6 Create 12. (i)Illustrate about LEO & MEO. (8)

(ii)Examine the operation of DAB with neat diagrams. (8)

BTL 4 Analyze 13. Summarize the main features and services offered by the

orbcomm satellite system. (16)

BTL 5 Evaluate

14.

(i)Show how the demand assigned multiple access and various configuration used on VSAT (8)

(ii)Write a short note on RADARSAT. (8)

BTL1 Remember