In mobile telephony explain in detail the functions of base station and mobile switching centre.

Explain, how digital coding can help in overcoming the burst error noise in signal transmission.

Explain the working of Armstrong system of frequency modulation using a block diagram. Which discrete component circuit could be used to attain the required phase shift?

Calculate the noise power and noise voltage generated by a 1M resistor at

C over a 1 MHz bandwidth

Three messages A, B, C have probabilities 0.4, 0.3 and 0.3 respectively, of their occurrences. If total 100 massages are sent out, calculate the total information (I_total) carried by them. Also calculate the entropy of the signal.

A plane wave is described by an electric field

What is its (i) frequency in Hz, (ii) wave number, (iii) phase velocity, (iv) wavelength, and (v) direction of propagation?

What approach is followed in practice for the choice of a propagation medium for any communication system? Why is a linear medium of propagation preferred?

State with reasons whether the following statements are True or False.

i) Rise time of a pulse is the time required for the amplitude to reach from 0% to 100% of the peak amplitude value.

ii) All types of device noise are white noise.

iii) Standing wave ratio of a matched transmission line is infinite. iv) Frequency modulation index mf is independent of carrier frequency.

v) Frequency shift keying is modulation of digital carrier signal with an analog intelligent signal.

vi) In superheterodyne receiver the local oscillator always operates at a fixed frequency.

vii) The depth of LCD TV depends on the size of its screen.

viii) Waveguide attenuator causes rotation of plane of polarization of the wave.

ix) Token ring protocol suffers with the data collision problem.

x) WAP helps in connecting devices without cables.

Expound the South Asia Co-operative Environment Programme with its aims and mission, organisation structure, and function

What is participatory approach and participatory irrigation management?

Explain mountain ecosystem.

Discuss the role of women in environment and development.

Elucidate the essential elements of integrated coastal management.

Elucidate the essential elements of integrated coastal management.

Describe the policy trends in joint forest management.

‘The ‘content of change’ and ‘contexts of change’ are strategies that intend to change the attitude and professional ideology as well as restructure the organisational setup of the government.’ Elaborate.

Write a note on participatory development along with the principles and constraints to participation.

Discuss the National Conservation Strategy in Pakistan along with the broad approaches to its development.

Discuss the role of Civil Society Organisations in information dissemination.

Briefly discuss the concept of disaster recovery planning.