This document outlines the modules and topics covered in a tutorial on mobile and cellular communication systems. The modules cover: 1) Generations of mobile systems and standards like GSM, 2) Signal propagation effects like fading and factors that influence it, 3) Diversity schemes to mitigate fading, 4) Interference in cellular systems, 5) Cellular network concepts like frequency reuse and handoff, 6) Antenna design for mobile networks, 7) Spread spectrum techniques like CDMA and their use in cellular standards. Key concepts discussed include characteristics of mobile radio channels, propagation models, diversity methods, interference reduction techniques, cellular network operation and capacity optimization.

1. TUTORIAL
EC 7113 MOBILE & CELLULAR COMMUNICATION
Module- 1:
1. Discuss the characteristic features of various generations of mobile communication
systems.
2. Discuss the characteristics of GSM system.
3. Compare AMPS and ETACS systems.
4. Discuss standards of GSM systems.
5. Discuss the key requirement technologies for the 4G systems.
6. Enumerate the expectations from 4G mobile communication system
7. Explain the following Blue tooth, WLAN, , PAN
8. Discuss the following UMTS, 4G, GSM, IMT-2000, PCS
9. Explain the concept of OFDM, CDMA, QAM, GMSK.
Module - 2:
1. Calculate the fading frequency when one incoming wave is perpendicular to the
vehicle motion.
2. A mobile unit is moving with a velocity V long a road between the transmitter and one
scatter. Show that the received signal at the mobile unit form a standing wave.
3. What is the difference between mobile path and radio path?
4. What do you mean by signal fading? Define long-term fading and short term fading.
5. What are the causes of long-term fading and short term fading?
6. A mobile unit is moving with a velocity V in absence of any scatterer, Derive the
expression for Doppler frequency and received frequency.
7. A mobile unit is receiving two incoming reflected waves of equal amplitudes at angles
? = 00 and ? = ?10. Derive the expression for fading frequency.
8. Obtain the general formula for fading frequency for two incoming waves at angles ?1
and ?2 w.r.t. the motion of the vehicle.
9. Define the appropriate PDFs, which represent long-term fading and short-term fading.

2. 10. Define level-crossing rate (ler) and average and duration of fade (adf).
11. Explain the term 'Coherence bandwidth'.
12. What is the delay spread?
13. What do you mean by the statement- 'The mobile radio signal can be assume to be
an ergodic process.'?
14. Explain the terms: (a) Time selective fading (b) frequency selective fading.
15. What do you understand by multipath fading? Discuss short term and long term
fading.
16. What are those factors that affect small scale fading?
17. What effects multipath creates on received signal?
18. How will you represent the field strength of a mobile signal?
19. Discuss time domain and space domain representation of mobile signals.
20. Derive an expression for the propagation path loss in an open space.
21. How do you differentiate between the propagation path loss in open space and in
mobile wireless environment?
22. What are the factors on which the propagation path loss depends in mobile
environment?
23. Discuss mobile radio environment.
24. Explain Rayleigh PDF and Rician PDF.
25. Explain the terms radio horizon and differentiate between mobile path and radio
path.
26. Explain with suitable example delay spread, coherence bandwidth, coherence time.
27. Discuss two ray ground reflection model.
28. Discuss knife edge diffraction model.
29. Explain the advantage and disadvantage of two ray ground reflection model in the
analysis of path loss.
30. Name different PDFs to describe the mobile radio environment.
31. Discuss Log normal PDF.

3. 32. Discuss the relevance of Rayleigh PDF in mobile communication environment.
33. Derive an expression for the Rayleigh PDF
34. How do you differentiate between Rayleigh and Rician PDFs?
35. What do you mean be fading channels?
36. Explain the basic mechanism of signal propagation in mobile radio environment.
37. What do you mean by dispersive and non dispersive channels?
38. Explain the characteristics of time dispersive channel?
39. Explain the various types of averages used in statistical communications theory.
40. Explain the term ergodic process with the help of a suitable example.
41. Differentiate between small scale and large scale fading.
42. Name various propagation models used to describe small scale and large scale
fading.
43. Explain Durkin's model in detail.
44. What do you mean by partition losses?
45. Explain the propagation models that take onto consideration the partition losses.
46. Explain Longely rice model, Okumura and Hata model, long distance path loss
model. Attenuation factor model.
47. What should be the propagation frequency in order to form a multipath propagation
medium?
48. Generally no radio horizon needed to be considered in base to mobile link. Why?
49. What are the considerations for outdoor and indoor propagation models?
50. Explain Clarks model in detail
51. Discuss various situations in which multipath occurs and explain one of the situation
in detail.
52. Describe max excess delay, mean delay and delay spread with suitable examples.
53. What do you mean by coherence bandwidth? How it is related with delay spread?
54. Name various outdoor propagation model and explain one of them.

4. 55. What is coherence band width? What is its effect with reference to the channel
bandwidth?
Module – 3:
1. Discuss the advantages of space diversity antennas used at cell site.
2. Explain the space diversity and frequency diversity. Explain the advantages and
disadvantages of major combining techniques used in mobile communication.
3. Name various microscopic diversity schemes and explain them
4. Explain why physically the space diversity scheme requires larger antenna separation
in the base station but smaller antenna separation at the mobile unit.
5. What do you mean by diversity reception? Discuss various diversity schemes.
6. Discuss various combining techniques
7. Explain the advantage and disadvantage of major combining techniques used in
mobile Communications.
Module- 4:
1. Discuss co channel channel interference.
2. Explain the methods to reduce the co channel interference
3. Explain the significance of the term 'co-channel reduction factor'.
4. What is adjacent- channel interference?
5. Explain (i) Inter symbolic interference (ii) Simulcast Interference (iii) Noise in mobile
environment
6. What is near end to far end interference ratio/ how can you reduce it?
7. Explain noise limited and interference limited environments.
Module- 5:
1. Discuss in detail the concept of frequency reuse.
2. Explain cellular concept. What is hand-off in cellular communication? What do you
mean by channel efficiency?
3. Discuss the operation of a cellular system.
4. Explain the functioning of MTSO and BSC

5. 5. Discuss the concept of hand off in mobile communication.
6. What are hard hand off and soft hand off?
7. Why CDMA is able to achieve soft hand off?
8. Differentiate between channel sharing and channel borrowing.
9. Discuss various channel assignment strategies.
10. Discuss various schemes to improve spectral efficiency.
11. Discuss multiple channel bandwidth system.
12. Discuss one third channel offset scheme.
13. Discuss different types of co channel assignments.
14. Discuss constant minimum C/I for all channels assignment strategy.
15. Discuss different minimum C/I among all channels assignment strategy.
16. Discuss the mechanism to improve coverage and capacity of a cellular system.
17. Explain why the co channel interference is reduced in one third offset channel offset
scheme?
18. Explain the conditions in which hand off should be delayed?
19. Discuss the features of micro cell.
20. Discuss the advantage of using CDMA in cellular system.
21. Discuss the key elements of designing a cellular system.
22. Discuss the various channel assignment strategies in mobile communication
systems.
23. Discuss channel efficiency and spectral efficiency.
24. Describe hand off procedure in mobile communication. Differentiate between hard
hand off and soft hand off.
25. Draw the frequency reuse cell pattern with reuse factor of 3.
26. Explain the mechanism of inter cell handover of a mobile station.
27. What are the frequency bands used for cellular mobile communications?

6. 28. What is the role of mobile services switching centre?
29. What is cell splitting?
30. Explain (i) channel sharing (ii) channel borrowing (iii) underlay/ overlay.
31. Discuss the Key elements in designing cellular system
32. Discuss Microcell system design
Module – 6:
1. Explain why a vertically polarized wave is preferred over a Horizontal polarized wave
for a mobile radio communication.
2. Why is the antenna separation at the base station wider when the antenna height is
higher?
3. Explain why the vertical separation of two diversity antennas is not desired.
4. Write short notes on:
• Antennas for mobile unit
• Features of cell site antennas
5. Show that the received signal in a mobile radio environment is a constant,
independent of the directivity of the directional antenna.
Module- 7:
1. Explain the concept of spread spectrum system. What are the characteristics of
spread spectrum system?
2. Enumerate various kinds of spreading techniques.
3. Explain how frequency hopped spread spectrum technique is used in mobile radio
communication system.
4. Explain what you understand by multiple accesses. What are FDMA and CDMA?
5. Discuss frequency hopping and explain frequency hop pattern.
6. Explain direct sequence spread spectrum technique.
7. With the help of block diagram discuss the transmitter and receiver of
DS-SS system.
8. Discuss advantage of spread spectrum techniques.
9. Discuss the natural attributes of CDMA.

7. 10. Explain the channel architecture of a CDMA system
11. State the advantage and disadvantage of CDMA.
12. Explain the channel architecture of a TDMA system
13. State the advantage and disadvantage of TDMA.
14. Write a note on any CDMA standard.
15. What is the advantage of using frequency hopping in fading channel?
16. Discuss the capacity of a cellular CDMA system.
17. Comment on the capacity of cellular systems.