Draw and Explain GSM system architecture.
[7 marks]Why hexagonal cell shape is preferred in cellular architecture?
[3 marks]Illustrating the upgrade paths 2G and 3G cellular network and describe in brief.
[4 marks]Explain the following terms :
[3 marks]Cell dragging (ii) RSSI (iii) Dwell time
[ marks]Explain the concept of frequency reuse in cellular system.
[4 marks]For a regular hexagonal geometry show that co-channel reuse ratio is Q = √3N , where N= i2+ij+j2.
[7 marks]If a signal to interference ratio of 15 dB is required for satisfactory forward channel performance of a cellular system, what is the frequency reuse factor and cluster size that should be used for maximum capacity if the path loss exponent is (1) n=4 (2) n=3 ? Assume that there are six co channel cells in the first tier and all of them are at the same distance from the mobile. Use suitable approximations.
[7 marks]Briefly describe Hand-off strategies in cellular system.
[3 marks]Briefly explain different channel assignment strategies.
[4 marks]Consider a transmitter which radiates a sinusoidal carrier frequency of 1850 Mhz. For a vehicle moving 60 mph, compute the received carrier frequency if the mobile is moving: i. Directly toward the transmitter. ii. Directly away from the transmitter. iii. In a direction which is perpendicular to the direction of arrival of transmitted signal.
[7 marks]Explain the concept of umbrella cell.
[3 marks]Mention the techniques to improve the capacity in cellular system and explain any one.
[4 marks]Aunit gain antenna with a maximum dimension of 1 m produces 50 Wpower at 900 MHz. Find (i) the transmit power in dBm and dB, (ii) the received power at a free space distance of 5 m and 100 m.
[7 marks]What is Brewster angle?
[3 marks]Explain: I-persistent CSMA, non-persistent CSMA, p-persistent CSMA.
[4 marks]Explain free space propagation model with necessary equations. OR1
[7 marks]What is Huygen’s principle?
[3 marks]Compare TDMA, FDMA and CDMA techniques.
[4 marks]Describe the various outdoor propagation models.
[7 marks]Explain three types of soft handoffs in IS-95 standard.
[3 marks]Compare Wi-Fi and WiMAX.
[4 marks]Explain the working of UWB radio. Discuss the features, advantages and disadvantages of UWB technology.
[7 marks]Give the classification of GSM channels.
[3 marks]Determine frame efficiency of a TDMA frame structure used in GSM system.
[4 marks]Write a short note on OFDM.
[7 marks]