Download COMP10023 - UWS Mahara

School of Computing
Hamilton & Paisley Campuses
Session 2013 – 14
Trimester 2
Module Code: COMP10023
WIRELESS NETWORKING
Date: 23 May 2014
Time: 1000 - 1200
SECTION A Answer ALL questions (each question is worth 2 marks)
SECTION B Answer FOUR questions (each question is worth 12 marks)
Exam paper to be handed in along with answer book
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COMP10023
SECTION A
Attempt ALL Questions – each question is worth 2 marks
Note that by default one option is correct unless you are instructed to choose
two. Two points for each question. When there are two correct options, one
point for each correct option and zero points if more options are selected than
required.
Please circle your answer(s).
1.
In an S-MAC sensor network, the sleep period is 750 ms and the frame
duration is 1,000 ms. What is the duty cycle in this network?
2.
a.
10%
b.
75%
c.
25%
d.
Need more information to determine
Which of the following techniques is NOT directly relevant in delivering or
evaluating a video over IP transmission in wireless networks?
3.
a.
UDP or TCP
b.
Packetisation
c.
Encoding
d.
Error concealment
e.
Subjective assessment
f.
None of the above
Which statement is NOT correct concerning Bluetooth?
a.
Based on OFDM
b.
Enables Internet of Things
c.
Supports transfer rate up to 24 Mbps
d.
Can sent information over a distance up to 100 m
e.
Adaptive frequency hopping mitigates interference with WiFi
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COMP10023
4.
Which two statements best describe a typical wireless mesh network? (Choose
two)
a.
A special case of infrastructure network
b.
Provides NLOS connectivity
c.
Easy to set up but difficult to maintain
d.
Multipoint-to-multipoint communication yet to be achieved
e.
Dependence of power-consumption constraints on the type of mesh
nodes
f.
5.
6.
Mesh routers need mobility support
Which two statements best describe OFDM? (Choose two)
a.
Also a frequency hopping technology
b.
Low data rate per sub-carrier
c.
Used in IEEE 802.11n and 802.16e
d.
Carrier sensing is performed
e.
Orthogonality is best seen in the space domain
f.
Based on spread spectrum technology
Which of the following descriptions are correct regarding AODV? (Choose two)
a.
Table-driven routing
b.
Destination-initiated routing
c.
Proactive routing
d.
Source-initiated routing
e.
Reactive routing
f.
Not applicable to mesh networks
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COMP10023
7.
8.
9.
What is the primary purpose of Contention Window in CSMA?
a.
Essentially eliminates contention among the nodes
b.
Statistically allows every node equal access to the media
c.
Provides a free channel for the node that has requested to send data
d.
None of the above
RTS and CTS are used for (Choose two)
a.
Defining the backoff period
b.
Resolving hidden terminal problem
c.
Recovering from network congestion
d.
Virtual carrier sensing
e.
Synchronisation of neighbouring nodes
f.
Error detection
Select the statement that is correct concerning Wi-Fi.
a.
Addresses 1, 2, 3, and 4 in the MAC header are present in all data frames
b.
Distributed Coordination Function (DCF) is a mandatory capability
c.
The FCS is not a mandatory field in the MAC header
d.
The Frame Body field is of fixed size
10. Select the correct statement concerning the spread spectrum technology.
a.
Break one high-speed data carrier into several lower-speed sub-carriers
b.
Use narrower bandwidth
c.
Use higher power
d.
Used in CDMA and WLAN systems
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COMP10023
11. Which statement is NOT correct regarding cellular systems?
a.
Exploits power falloff with distance
b.
Base stations perform centralized control functions
c.
System capacity is interference-limited
d.
The most widely used metric for handoff detection is the date rate
e.
Employs a hierarchical networking architecture
END OF SECTION /-
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COMP10023
SECTION B
CHOOSE 4 of the 5 Questions to Attempt – Each questions is worth 12 marks
1.
Introduce the evolution of cellular systems from 2G towards 4G.
a.
2.
Specify the representative European systems for 2G/2.5G, 3G, and
beyond 3G (or 4G).
(3)
b.
Briefly compare the infrastructure evolution in these systems.
.(3)
c.
Specify the typical MAC schemes for each generation.
..(3)
d.
Outline the typical applications/services provided by these systems.
(3)
Before a WiFi wireless router is connected to the rest of the existing network,
proper configuration of the wireless router is necessary. Router firmware
upgrading may also be needed for enhanced performance or functionality.
a.
List and briefly explain the necessary initial configurations of a wireless
router through web-based approach.
b.
(6)
Identify the most common means for a user to upgrade the firmware; list
one open source firmware resource for wireless router upgrading; list one
c.
specific reason for firmware upgrading.
(3)
Describe the process for a Wi-Fi client to connect to a Wi-Fi network.
(3)
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COMP10023
3.
The following parameters are known in a wireless network VoIP codec: the
voice packetisation interval is 20 ms, the raw voice bit rate is 12.2 Kbps, and
the standard RTP/UDP/IPv4 protocol suite is used to transmit the VoIP
packets.
a.
Specify the subsystem that supports VoIP in 3GPP networks, and the
primary application-level protocol that manages VoIP sessions.
(4)
b.
Calculate the voice payload size after packetisation.
(4)
c.
Calculate the minimal required bandwidth at the IP level to transmit the
VoIP packets in one direction (assuming basic headers without option
fields and no header compression or silence suppression used).
4.
(4)
Compare among generic mobile ad hoc networks, typical wireless sensor
networks, and hybrid wireless mesh networks. The following aspects may be
taken into account in the comparison: advantages and disadvantages
compared with infrastructure networks, typical network topology, network
protocols, main design concerns, targeted applications, standardisation, and so
on.
a.
5.
Plot 3 diagrams for a generic mobile ad hoc network, a typical wireless
sensor networks, and a hybrid wireless mesh network, respectively
(3)
b.
Describe three similarities among these networks
(3)
c.
Describe six differences among these networks
(6)
Mobile IP is the de-facto standard IP-based mobility management protocol.
a.
Briefly explain why standard IP addressing and routing is unable to deal
with IP mobility.
(2)
b. Plot a diagram showing the key elements and triangular routing in a basic
Mobile IPv4 network.
c.
(4)
Outline the operation of basic Mobile IPv6 without Route Optimisation. (6)
END OF EXAM PAPER
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