Hall Ticket No Question Paper Code: BESB03
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
M.Tech I Semester End Examinations (Regular) January, 2019
Regulation: IARE-R18
WIRELESS LANS AND PANS
Time: 3 Hours Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. How does 4G networks provide more speed than 3G networks? Why doesn't a 3G mobile phone
support 4G networks?
A large population of ALOHA users generates 50 request/sec. Time is slotted
in units of 40msec.
i. What is the chance of success on the first attempt?
ii. What is the probability of exactly k collisions and then a success?
iii. What is the expected number of transmission attempts needed.
iv. What is the channel load G.
2. Which multiple access technique is used by IEEE 802.11 standard? Explain in detail about
CSMA/CA.
Discuss about technical issues in wireless communications and what are the advantages of wireless
networks.
UNIT II
3. Explain the principle behind spread spectrum technique and how this is used to minimize interference
in a CDMA system. Also determine the throughput efficiency of the system.
What are the issues that should be considered in deploying the WLAN's?
4. Explicate wireless local area network technologies in detail and illustrate the comparisons between
them.
How pseudo random numbers are generated? Explain FHSS and DSSS CDMA in detail.
UNIT III
5. Explain about hidden node issue problem specific to WLAN in MAC layer.
Elucidate the security services provided by IEEE 802.11
6. Discuss in detail about hidden terminal problem, reliability, collision avoidance and congestion
avaoidance corresponding to MAC layer issues.
What is the significance of physical layer? With design flow diagram, explain different sub layers
present with- in the sub layer.
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UNIT IV
7. How does Bluetooth fit in with Wifi? How many devices can communicate concurrently? Name
few applications of Bluetooth?
Explain about the Load Adaptive algorithm. What are the parameters to be considered for its
functioning.
8. Illuminate how efficient integration between bluetooth WPANs and IEEE 802.11 WLANs is done.

What are the different security levels that can be defined for devices and services offered by
Bluetooth.
UNIT V
9. Explain all the power saving features of IEEE 802.15.4. Also, explain the situations in which
features could be useful.
Differentiate between ZigBee and Bluetooth. Explain the architecture of Zigbee technology with
Zigbee components and network topology.
10. Write a short note on Physical Layer w.r.t IEEE 802.15.4
Explain LR-WPAN device architecture with suitable diagram.