Wireless Network - May 2014

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 RAKE receiver inCDMA.(5 marks) 1(b) Explain various states in bluetooth.(5 marks) 1(c) What is the 'hidden' and 'exposed' node in WLAN?(5 marks) 1(d) What are wireless is sensor networks?(5 marks) 2(a) Explain the forward features in CDMA 2000.(10 marks) 2(b) Give technical difference between CDMA 2000 and WCDMA with respect to the core network,channel bandwidth,chip rate,modulation,mode of operation,source identification codes for sector and moblic,channel coding and overhead.(10 marks) 3(a) Explain link budget analysis and requirement of wireless networks.(10 marks) 3(b) Explain back-off algorithm why is CSMA-CD not used in WLAN?(10 marks) 4(a) Explain the following
Bluetooth protocol stack
Bluetooth security aspects.(10 marks) 4(b) The IEE 802.11 WLAN uses a 64bit sub channel implementation of multicarrier modulation (OFDM).48 subcarrier are used for information transmission.4 subcarrier for pilot tones are used for synchronization and 12 are reserved.Each sub channel has a symbol rate of 250 kilo symbol per second.the occupied bandwidth is 20 MHz.Find the bandwidth of a subchannel.what is modulation efficiency?What is a user symbol rate?If 16-QAM modulation is used,what is the user data rate if the information bits are encoded with a rate of 3/4?If the guard of time between two transmitted symbols is 800ms,what is the time utilization efficiency of the system?(10 marks) 5(a) Explain WAP architecture in detail.(10 marks) 5(b) Draw a neat block diagram For UMTS architecture.Explain all the interfaces.(10 marks) 6(a) Explain HSDPA,emphasizing its primary objective and how it achieves performance improvements.(10 marks) 6(b) Describe the model of wireless sensor network.What are the factor influencing design of a wireless sensor network?(10 marks)

Any two

7(a)

Write short notes on any two:
Zigbee Technology