Mobile Computing - December 2014

MU Computer Engineering (Semester 7)

Total marks: --
Total time: -- INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary 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 cellular system using a seven cell reuse pattern each cell has a radius of 4 miles and the city has 40 Mhz spectrum with a full duplex channel bandwidth of 60 Khz Find:
i) The number of cells in the service area.
ii) The number of channels per cell.
iii) Total number of subscribers that can be served 10 marks

2 (a) Write about types of antennas and their radiation pattern? 10 marks

2 (b) Describe how data encryption is done is GSM system, with diagram explaining the role of SIM, A3, A5 and A8 algorithm. 10 marks

3 (a) What are various types of satellites are used? Describes there functionality and also explain the concept of localization, routing and handover in them. 10 marks

3 (b) The channel access control sublayer 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 difference of WML compared to HTML? Why is this difference important with respect to handheld devices? What is specified in addition to save bandwidth? 10 marks

4 (b) What are the general problems 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 Session Protocol (WSP)? 10 marks

5 (b) What are the modifications 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 format of an IEEE 802.11 using the spread spectrum technique which separates by code. 10 marks

6 (b) Discuss IMT 2000 system. 10 marks

7 (a) Explain in short Wireless Security Threats. 10 marks

7 (b) What do you mean by WIMAX? In what way it is similar to DSL? 10 marks

7 (c) Discuss about Link Management in Wireless ATM. 10 marks

7 (d) What is hand-off? What is roaming? How do you perform hand-off during roaming? 10 marks