Wireless Network - May 2013

Electronics & Telecomm. (Semester 8)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1 (a) Explain forward link features of CDMA 2000. (4 marks) 1 (b) Explain concept of HSDPA with respect of WCDMA.(4 marks) 1 (c) What is adaptive multiratecoding?(4 marks) 1 (d) Give different WLAN topologies.(4 marks) 1 (e) Explain the concept of OFDM.(4 marks) 2 (a) Explain in detail components of sensor node.(10 marks) 2 (b) Explain in detail various IEEE 802.11 standard used in wireless Network.(10 marks) 3 (a) Differentiate between: (i) CDMA 2000 and WCDMA.
(ii) IS-95 and CDMA 2000(10 marks) 3 (b) Calculate the downlink cell load-factor and number of voice users per cell for a WCDMA system using the following data -
- Information rate (Ri) = 12.2 kbps
- Chip Rate(Rc) = 3.84 Mcps
- Required Eb/Nt = 4dB
- Average interference factor due to other cells = 0.5
- Orthogonal factor = 0.6
- Interference margin = 3db.(10 marks) 4 (a) Give UMTS Air-interface specifications. Also explain 3 types of channels defined in UMTS.(10 marks) 4 (b) Explain Bluetooth protocol stack.(10 marks) 5 (a) Describe the forward and reverse link physical channels for CDMA 2000.(10 marks) 5 (b) Explain WLAN technologies in detail.(10 marks) 6 (a) Discuss in detail WAP programming model.(10 marks) 6 (b) Using the following data for GSM1800, develop downlink and uplink budgets and determine the cell radius.
- Base station transmit power (P_b) = 36 dBm = 4W
- Mobile station transmit power (P_m) = 24 dBm
- Mobile station (hand-held unit) noise figure = 8 dB
- Base station noise figure = 5 dB
- Base station transmit and receive antenna gain (G_A) = 18 dBi
- Mobile antenna gain = 0 dBi
- Required signal-to-noise ratio (SNR) = 12 dB
- BS transmit antenna cable, connector, and filter losses (L_c) = 5 dB
- BS receiver antenna cable, connector, and filter losses (L_c) = 2 dB
- Orientation/body losses at mobile = 3 dB
- Shadow fading = 10.2 dB
- Thermal noise density = -174 dBm/Hz
- Antenna diversity gain at B_S = 5 dB(10 marks)

Write shorts notes on the following:-

7 (a) Wimax.(10 marks) 7 (b) Zigbee protocol.(10 marks)