Code No: C9305 JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD M.Tech I SEMESTER EXAMINATIONS, APRIL/MAY-2013 ADVANCED DATA COMMUNICATIONS (SYSTEMS AND SIGNAL PROCESSING) Time: 3hours Max.Marks:60 Answer any five questions All questions carry equal marks - - - 1. If a binary data is to be transmitted using the following modulation schemes, give the procedure to generate modulated, and demodulated signals for each scheme to retrieve the original data in AWGN channel conditions: a) 8-PSK b) 8-QAM 2.a) What are the primary functions of UART (Universal Asynchronous Receiver Transmitter)? b) With suitable block diagram(s), explain how the information is transferred between Data Terminal Equipment (DTE) and (Data Communication Equipment (DCE). 3. Describe the mechanical, electrical, and functional specifications of RS-232 serial interface standard. 4.a) Discuss about vari ous t ypes of error detection methods available i n data communication. b) For a 12-bit data string o f 101100010010, d etermine the number of Hamming bits required arbitrarily place the Hamming bits into the data string. Also determine the logic condition of each Hamming bit. Assume an arbitrary single bit transmission error, and prove that the Hamming code will successfully detect the error. 5.a) With suitable frame format, discuss about SDLC synchronous protocol. Also explain what is meant by ‘transparency’? b) Determine the bit pattern for the control field of a supervisory frame sent from a secondary station to the primary for the following conditions: (i) Secondary is ready to receive (ii) it is a f inal frame (iii) Secondary is confirming correct reception of frames 3, 4, and 5. 6.a) With suitable sketches, explain the following: i) circuit switching ii) packet switching, and iii) datagram. b) For the European E1 32 channel system with number of bits per frame is 256 and number of bits in the synchronizing word is 8, and a 2.048 Mbps transmission rate, determine the average number of bits needed to synchronize and the average synchronization time. R09 www.jntuworld.com www.jntuworld.com www.jwjobs.net www.android.jntuworld.com