Mobile Communication & Computing - Dec 2014

Computer Engineering (Semester 6)

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) Consider a mobile user who is migrating from a place to another place provide him a seamless service by satellite system,also sketch the architecture.(10 marks) 1(b) A certain city has an area of 1300 square miles and is covered by a Marcellus system using a seven cell reuse pattern "Each cell has a radius of 4 miles and the city has 40MHz spectrum with a full duplex channel bandwidth of 60KHz find:
The number of cells in the service area 7
The number of channel per cell 1500
Total number of subscribers that can be served 10500(10 marks) 2(a) Write about types of antennas and their radiation pattern?(10 marks) 2(b) Describe how data encryption is done in GSM system,with diagram explaining the role of SIM ,A3,A5 and AB algorithm.(10 marks) 3(a) What are various types of satellites are used?Describe there functionality and also explain the concept of localization,routing and handover in them.(10 marks) 3(b) The channel access control sub-layer of HiperLAN offers a connectionless data transfer service to the higher MAC layer.Justify the above statement with related references.(10 marks) 4(a) What is the fundamental different of WML compared to HTML? Why is this difference important with respect to handled devices? What is specified in addition to save bandwidth?(10 marks) 4(b) What are the general problem of mobile IP regarding security and support of quality of service?(10 marks) 5(a) Explain the transaction classes provided by wireless Transaction protocol(WTP)?Also explain services provided by wireless protocol(WSP)?(10 marks) 5(b) What are the modification require to an existing GSM network to be upgraded to GPRS?Explain with the help of Diagram.(10 marks) 6(a) Discuss the PHY frame formate of an IEEE 802.11 using the spread spectrum techniques which separates by code.(10 marks) 6(b) Discuss IMT 2000 system.(10 marks) 7(a) Explain in short wireless security Threats.(5 marks) 7(b) What do you mean by WiMAX? In what way it is similar to DSL?(5 marks) 7(c) Discuss about Link Management in Wireless ATM.(5 marks) 7(d) What is handoff? What is roaming? How do you perform handoff during roaming?(5 marks)