Chapter-1:
Overview of Computer Networks
January-2004 [0]
July-2004 [10]
1.
e) Give
an example protocol for each of the following layers in the OSI
network stack: MAC, Network, Transport, Session. [4]
4.
a) What
are the advantages of a layered protocol design and implementation?
Suppose a new link layer technology is invented today, explain, how
layering helps in integrating this technology into the current
Internet? [4]
b) Can
there be a network stack implementation, which does not include all
the layers of the OSI reference model? Explain the significance of
the word "reference". [2]
January-2005 [10]
1.
a) Explain
the relationship between layers at an interface by defining PDU, SDU
and IDU. [4]
7. Write
short notes on
c) Traditional
and mobile transport layer. [6]
July-2005 [18]
2.
a) Discuss
the major advantages and disadvantages of layered model? How many
layers are used in mobile communication systems? Name them.
[9]
b) What
do you understand by “broadcast network”? Discuss the need for a
network layer (OSI layer 3) in a broadcast network. [9]
January-2006 [16]
1.
a) How
do the layers of TCP/IP protocol suite correlate to the layers of the
OSI? [4]
2.
a) What
are connection oriented and connectionless services? What are service
primitives? Explain with an example how these are used.
[6]
b) Discuss
the role of transport layer and data link layer in the OSI model.
[6]
July-2006 [30]
1.
a) What
is a bridge? Discuss the purpose and advantages of a bridge.
[4]
c) Explain
the terms Attenuation, Delay, distortion and noise. [4]
f) Explain
the concept of interfaces and services. What is the relation between
Layers at an interface? [4]
3.
a) Discuss
the advantages and disadvantages of packet switching over circuit
switching? [6]
7. Write
short notes on the following:
b) Comparison
between OSI reference model and TCP/IP suite [6]
c) Traditional
and mobile transport layer [6]
January-2007 [9]
3.
a) Explain
the data transfer services that OSI defines for the discrete data
components passed across the interface and between peer entities.
[9]
July-2007 [23]
1.
d) What
are the types of care-of-address in mobile IP? [4]
f) What
are the classes of IP addressing scheme and how many numbers of
host-Ids and Network-Ids are there in each class? [4]
4.
a) Mobile
IP provides the ability of a host to stay connected to the internet
regardless of their location and without needing to change the mobile
host’s long-term IP address. Explain Mobile IP operation with
suitable diagrams. [9]
5.
a) Open
System Interconnection is widely used for communication standard.
What are Interface Data Unit, Service Data Unit and Protocol Data
Unit with reference to OSI model? [6]
January-2008 [8]
1.
a) How
does LLC sublayer ensure to transport efficiently multimedia traffic
over the radio interface? [4]
4.
a) What
are the advantages and disadvantages of layered model? [4]
Chapter-2:
Multiple Access Technologies for Wireless Communication
January-2004 [8]
1.
e) Is
it possible to transmit a digital signal e.g. coded as square wave as
used inside a computer using radio transmission without any loss? If
yes, how and why? [4]
f) What
limits the number of simultaneous users In a TDM/FDM system compared
to a CDMA system? What happens to the transmission quality of
connections if the load gets higher in a cell? How does an additional
user Influence the other users in the cell? [4]
July-2004 [0]
January-2005 [23]
1.
b) Give
four reasons for the failure of many MAC layer (used in wired
networks) protocols being applied to wireless networks.
[4]
e) What
is QPSK? How is it used in CDMA? [4]
2.
a) Explain,
how does Slotted ALOHA work? Compare and contrast the basic MAC
technologies used in FDMA, TDMA and CDMA. [9]
7. Write
short notes on
a) Efficient
frequency utilization techniques employed in mobile communications.
[6]
July-2005 [22]
1.
a) For
a cluster of size N, how many total channels are available if each
cell is allocated a group of k channel in a Cellular System using
FDMA? [4]
3.
a) Discuss
the problems of hidden and exposed terminals. What happens in the
case of such terminals if ALOHA, slotted ALOHA or MACA is used?
[9]
4.
b) Briefly
discuss the operation of a CDMA multiple-access system. In what ways
is it superior to TDMA? Mention the potential applications of
CDMA. [9]
January-2006 [28]
1.
b) Compare
the performance of slotted aloha with that of pure aloha. What is the
limitation of aloha protocol in general? [4]
2.
c) What
is spread spectrum communication. Explain the terms processing gain,
pseudo random code generator and Walsch code. [6]
3.
b) Draw
the detailed block diagram of a cellular system and explain. Also
explain the different strategies implemented to avoid interferences
in TDMA, FDMA & CDMA systems. [9]
7.
b) What
is frequency management? Discuss different fixed channel assignment
strategies. What are its limitations are compared to non-fixed
channel assignment methods. [9]
July-2006 [10]
1.
d) What
are the various multiple access technologies for Cellular Systems?
Explain any one of them. [4]
4.
b) i) What
is the maximum throughput of a pure ALOHA network with large number
of
users
and transmission rate of 1 Mbps?
ii) What
is the throughput of a TDMA network with transmission rate of 1 Mbps?
- What is the throughput of the ALOHA network if only one user was effective with
transmission
rate of 1 Mbps? [6]
January-2007 [18]
1.
f) How
does CDMA system use signals that arrive in the receivers with
different time delays? [4]
2.
b) What
are the various strategies implemented to avoid interferences in
TDMA, FDMA & CDMA
systems. [5]
4.
b) Discuss
the problems of hidden and exposed terminals. What happens in the
case of such terminals if ALOHA, slotted ALOHO or MACA is used?
[9]
July-2007 [19]
1.
e) Time
Division Multiple Access is a technique of transmitting / receiving
data between two devices. How is data transferred in TDMA?
[4]
4.
b) A
pure ALOHA system used packets of size 1000 bits and channel
transmission rate of 10 Mbps. The packet generation is a Poisson
process with average rate of 103 packets/sec. Obtained the
normalization throughput. [9]
5.
c) How
is spread spectrum implemented by using frequency hopping?
[6]
January-2008 [21]
2.
a) A
pure ALOHA network transmits 200-bit frames on a shared channel of
200 kbps. What is the throughput if the system (all stations
together) produces 1000 frames? [6]
4.
c) Briefly
discuss the operation of a CDMA multiple access system. In what ways
it is superior to TDMA? Mention the potential application of CDMA.
[9]
5.
a) Differentiate
between slotted ALOHA and Pure ALOHA? Discuss the limitation of pure
ALOHA. [6]
Chapter-3:
Mobile Data Communication
January-2004 [62]
1.
a) Why
is frequency reuse necessary in cellular telephony? Find out the
expression for frequency reuse. [4]
b) Sometimes
when a cellular user crosses the boundary from one cell to another,
the current call is abruptly terminated, even though all transmitters
and receivers are functioning perfectly. Why? [4]
2.
a) What
are the main problems of signal propagation? Why do radio waves not
always follow a straight line? Why Is reflection both useful and
harmful? [9]
b) Discuss
the following techniques used to improve capacity in cellular system:
i) Cell
Splitting
ii) Sectoring.
Which
technique Is more efficient and why? [9]
3.
a) Explain
various channel assignment strategies used in cellular communication.
Describe how a mobile to wire line call is established in cellular
radio system. [9]
b) Determine
the number of full duplex channels available in a cluster and the
total capacity for a cellular system where there are 10 clusters,
each containing 20 cells with 18 channels in each cell. Also,
determine the co-channel reuse ratio for each cluster. [9]
4.
a) Describe
the handoff feature in a cellular radio system. Explain the
difference between soft and hard handoff. [10]
b) What
is co-channel interference? List various strategies to reduce
co-channel interference. Explain any two in detail. [8]
July-2004 [52]
1.
c) What
are the different ways in which radio waves can propagate? Mention
the role of the radio wavelength where it is relevant. What causes
multi-path interference? [4]
2.
a) Briefly
mention as to why control channels are required between a BTS and a
mobile. What is the control channel used by the BTS for passing
information regarding the cell parameters? What is the control
channel used to find out if a particular mobile is present in a
cell? [3]
b) Which
control channel is used for setting up a mobile originated call? Why
is collision between multiple mobiles possible in this case? What is
the multiple-access protocol used? How is the Access Grant Channel
(AGCH) used to reduce the number of collisions? [5]
c) What
is the need of a Fast Associated Dedicated Control Channel (FACCH)?
How is FACCH implemented? When is it used? [3]
4.
c) Suppose
that you have a simple packet switched network with three nodes A,
Band C connected as A-B-C, with B acting as a router for packets
between A and C. Suppose that both links A-B and B-C have a capacity
of B bytes/sec. The packets from A to C have a payload size of P
bytes and a header size of 40 bytes. What is the maximum throughput
possible' between A and C in terms of P and B? [2]
d) What
is the latency experienced by packets between A and C? Assume that
the propagation delays are negligible. [1]
e) Suppose
now that each payload is split into two fragments of (P/2) bytes
each. Each fragment thus has a separate header. What is the maximum
throughput possible in this scenario? [2]
f) In
the same fragmentation scenario as above, what is the latency seen by
packets between A and C (compute the latency of packets, not each of
the fragments). [3]
g) By
comparing your answers in parts (d) and (f) above, determine the
value of payload size P for which the latency is the same even after
fragmentation. How do the two latencies compare for lower values of P
than what you determined for higher values of P?
[4]
5.
a) While
measuring the signal strength to decide whether or not to handoff to
an adjacent cell, why is it important to average over time? Is
soft-handoff possible in a GSM network? Why or why not?
[2]
b) What
is ping-ponging effect in hand off? Does it occur in soft-handoff or
hard-handoff? How can it be prevented? [5]
c) Differentiate
between terminal mobility, personal mobility and service portability
with a brief explanation for each. [6]
7.
c) What
is the difference between error-detection and error-correction? Which
requires more overheads? [2]
d) What
is Hamming distance? Suppose the Hamming distance between two
codewords in an error-correcting scheme is 4, how many bit errors can
this scheme correct? Why? [3]
e) What
are the trade-offs in the use of error-correcting codes as opposed to
using ARQ? For what kind of applications is an error correcting code
more appropriate? [3]
f) What
is an error burst? Explain, how this can be countered using block
interleaving.
[4]
January-2005 [8]
1.
c) Give
the relations to calculate transmitted power and co-channel reuse
distance of wireless cellular systems. [4]
d) Explain
the terms ‘Handoff mechanism’ and ‘Cell splitting’.
[4]
July-2005 [38]
1.
c) Find
the co-channel reuse ratio Q if the cluster size N is 9.
[4]
d) What
is the difference between inter-cell handoff and intra-cell
handoff? [4]
f) Assume
all stations can hear all other stations. One station wants to
transmit and senses the carrier idle. Why can a collision still occur
after the start of transmission? [4]
3.
b) Differentiate
between Circuit Switched Data Services and Packet Switched Data
Services on Cellular Networks. [9]
4.
a) Discuss
the make-before-break and break-before-make handoff procedures.
Propose methods that could be used by a base station to determine the
vehicular speed of a mobile user. Are these methods useful for
handoff algorithms? [9]
8.
a) What
are the factions that influence small scale fading? What causes
multipath fading? How can Multipath fading be reduced?
[8]
January-2006 [17]
1.
c) Explain
the concepts of handoff and dropped call rate. What are soft and hard
handoffs. [4]
e) If
20 MHz of total spectrum is allocated for a duplex wireless cellular
system, with Simplex channel has 25KHz RF bandwidth, find the number
of duplex channels and number of channels per cell site, if N=12 cell
reuse is used. [4]
3.
a) What
are mobile data communication services and name them. Describe the
architecture of HSCSD (High Speed Circuit Switched Data).
[9]
July-2006 [10]
1.
g) Explain
the Circuit-Switched Data Services on Analog Cellular Networks.
[4]
2.
c) A
network is to be planned using cellular topology. If total available
bandwidth is 25MHz and each user requires 30KHz bandwidth for voice
communication. 20 lower power antennas are used and the frequency
band is divided in to four sets and one set is assigned to each cell.
Find the number of simultaneous users. [6]
January-2007 [19]
1.
c) What
are the different ways in which radio waves can propagate? Mention
the role of the radio wavelength where it is relevant. What causes
multi-path interference? [4]
5.
c) For
a cluster of size N, how many total channels are available if each
cell is allocated a group of k channel is a Cellular System using
FDMA? [6]
6.
b) Differentiate
between Circuit Switched Data Services and Packet Switched Data
Services on Cellular Networks. [9]
July-2007 [9]
7.
a) Cellular
Digital Packet Data (CDPD) was designed to maximize the use of
existing functions and capabilities in Analog Mobile Phone System.
Explain CDPD network architecture. [9]
January-2008 [31]
1.
e) List
four significant factors which influence the choice of speech-coders
in mobile communication. Which factor influences more as per your
opinion? Give reasons. [4]
g) Explain
the architecture and features of “Short Message Service”.
[4]
3.
a) What
is channelization? Explain at least two channelization protocols in
detail? [9]
4.
b) Explain
small scale multipath propagation. Discuss the factors that influence
small scale fading. [5]
7.
b) Discuss
the features of the following:
i) Circuit
Switched Data Services
ii) Packet
Switched Data Services. [9]
Chapter-4:
Personal Wireless Communication Systems
January-2004 [4]
1.
g) What
Is likely to happen to a DECT if it is deployed outdoors in an
environment where significant multipath could occur? Explain your
answer and provide qualitative analysis. [4]
July-2004 [3]
5.
e) What
is the role of the unique personal number in Universal Personal
Telecommunications (UPT)? [3]
January-2005 [0]
July-2005 [0]
January-2006 [18]
1.
d) Draw
and discuss the conceptual model of DECT (Digital European Cordless
Telephone). Give its application areas. [4]
4.
a) Give
an account of radio specifications for cordless telecommunication
systems such as CT2and DECT. [6]
c) Draw
and explain the functional architecture for PACS (Personal Access
Communication System). Discuss the frame structure and its radio
aspects. [8]
July-2006 [0]
January-2007 [0]
July-2007 [8]
2.
c) Describe
Digital Enhanced Cordless Telecommunication system and the protocol
architecture. [8]
January-2008 [10]
1.
c) What
are the data and messaging services supported by Personal Access
Communication System (PACS)? Explain briefly. [4]
5.
b) What
are the application areas of DECT? Discuss the conceptual model of
DECT in brief. [6]
Chapter-5:
Digital Cellular Systems and Standards (2G)
January-2004 [9]
7.
a) Describe
the GPRS architecture and protocols. How many of them already exist
In GSM? Compare the channel request procedure in GPRS with that in
GSM. [9]
July-2004 [17]
1.
g) Both
GSM and DECT are digital wireless communication standards for voice.
What is the difference in terms of the intended coverage area and
mobility supported by the two? Which one of them defines detailed
network architecture for roaming across various providers'
networks? [4]
2.
d) Draw
the GPRS architecture showing the main components. Which is the
component responsible for assignment of an IP address to the mobile?
Why does there need to be a mapping between the mobile's IMSI and its
IP address? [7]
5.
d) GSM
uses the SIM card to identify a particular user. The user can use the
same SIM card on any cellular phone. Is this an example of terminal
mobility or personal mobility? Why? [2]
7.
b) Which
is the 2G technology, which uses CDMA? How do the three CDMA variants
1XMC, 3XMC and HDR differ in terms of bandwidth usage? [4]
January-2005 [31]
1.
f) In
each GSM multi frame, 24 frames are used for traffic and two for
associated control signaling. Considering the detailed burst frame
and multi frames infrastructures, explain, how the effective
transmission rate for each GSM voice traffic is 22.8 kbps.
[4]
2.
b) Draw
the CDMA based mobile system architecture and explain how it provides
reliable basic phone services. Write the benefits of CDMA to
users. [9]
6.
a) Draw
the basic reference architecture and signaling interfaces of GSM. Why
SIM card needed in GSM, while it is not required in AMPS?
[9]
b) How
do you compare AMPS and GSM systems in terms of coverage area,
transmitted power and error control system? Explain, what you can do
to address adjacent channel and co-channel interference.
[9]
July-2005 [24]
5.
a) If
8 speech channels are supported on a single radio channel and if no
guard band is assumed, what is the number of simultaneous users that
can be accommodated in GSM? [9]
7.
a) Discuss
the GSM Reference Architecture in detail. What is the function of the
following:
i) Mobile
Station (MS)
ii) Base
Station System (BSS)
iii) HLR
- VLR
v) Authentication
Centre [10]
8.
b) Write
short notes on any two topics
i) GPRS
Architecture [5]
January-2006 [31]
1.
f) Compare
and contrast the various 2.5G technology paths that each of the major
2G standards provide. Which path has the highest Internet access
speed? [4]
5.
a) Draw
CDMA based mobile system architecture and explain, how it provides
reliable basic phone services. Write the benefits of CDMA to users.
[9]
b) Draw
the basic reference architecture and signaling interfaces for GSM.
Why is Smart card needed in GSM, while it is not required in AMPS?
[9]
6.
a) How
do you compare D-AMPS and GSM systems in terms of coverage area,
transmitted power and error control system, explain what you can do
to address adjacent channel and co-channel interference.
[9]
July-2006 [24]
2.
b) What
are the main elements of GSM System architecture? Discuss the reasons
of separate MS and SIM in GSM. [6]
4.
a) Using
QPSK modulation and convolutional coding, the IS-95 digital cellular
systems require 3dB < Sr < 9 dB. The bandwidth of
the channel is 1.25 MHz., and the transmission rate is R = 9600 bps.
Find the capacity of a single cell IS-95 cell. [6]
6.
a) What
is GPRS? Describe the GPRS architecture and protocols. [12]
January-2007 [23]
1.
e) In
each GSM multi frame, 24 frames are used for traffic and two for
associated control signaling. Considering the detailed burst frame
and multi frames infrastructures, explain, how the effective
transmission rate for each GSM voice traffic is 22.8 kbps.
[4]
2.
a) How
is signaling protocol in GSM structured into layers? What are the
specific functions performed by Layer 3 of the GSM signaling
protocol? [9]
c) If
a normal GSM time slot consists of six trailing bits, 8.25 guard
bits, 26 trailing bits and two traffic bursts of 58 bits of data,
find the frame efficiency. [4]
5.
b) Using
QPSK modulation and convolutional coding, the IS-95 digital cellular
systems require 3dB < Sr < 9 dB. The bandwidth of
the channel is 1.25 MHz., and the transmission rate is R = 9600 bps.
Find the capacity of a single cell IS-95 cell. [6]
July-2007 [10]
2.
a) General
Packet Radio System is radio access technology and provides packet
data service. Explain the protocol architecture. [5]
b) Explain
GSM architecture and frequency planning. [5]
January-2008 [15]
2.
c) If
GSM uses a frame structure where each frame consists of eight time
frame slots, and each time slot contains 156.25 bits, and data is
transmitted at 270.833 kbps in the channel. Find
i) The
time duration of a bit
ii) The
time duration of a slot
iii) The
time duration of frame. [6]
3.
b) Explain
the typical call flow sequences in GSM. [9]
Chapter-6:
Third Generation Mobile Services (3G)
January-2004 [0]
July-2004 [6]
1.
d) Give
an application as an example, which will find use for the "streaming"
class of QoS offered by UMTS. Also give an example application for
the "interactive" class. Which 2.5G architecture is the
UMTS core network based on? [4]
7.
a) What
is W-CDMA? What are its advantages over TDMA? [2]
January-2005 [18]
5.
a) Summarize
the main features of 3rd generation mobile phone system.
How do they achieve higher capacities? How does UMTS implement
asymmetrical communication and different data rates?
[9]
b) What
are the bandwidths and chip rates used in CDMA? Why does WCDMA use
walsh codes in forward and reverse channels for separating users
while in CDMA, one uses them only in forward channel. Assume
we want to support a 19.2 kbps data service with ber (bit error rate)
of 10-3 over WCDMA system. What is the minimum chip rate
and bandwidth needed to support 100 simultaneous users with one
carrier? Assume a performance improvement factor of K = 4(6dB).
[9]
July-2005 [17]
6.
b) Explain
various key characteristics that distinguish third generation
cellular systems from second-generation cellular systems.
[9]
7.
b) Differentiate
between W-CDMA and CDMA-2000 mobile services and standards.
[8]
January-2006 [9]
6.
b) With
the help of a neat diagram explain the UMTS (Universal Mobile
Telecommunication System) network architecture. Discuss in detail the
logical parts: I) user equipment and ii) core network. How is the
number of handoffs reduced of r the fast moving traffic? [9]
July-2006 [6]
2.
a) What
are the key features of IMT-2000? What are the general requirements
for Radio Access to IMT-2000? [6]
January-2007 [13]
1.
g) Compare
and contrast the various 2.5G technology paths that each of the major
2G standards provide. Which path has the highest Internet access
speed? [4]
4.
a) Summarize
the main features of 3rd generation mobile phone system.
How do they achieve higher capacities? How does UMTS implement
asymmetrical communication and different data rates?
[9]
July-2007 [18]
3.
a) Describe
Functional Network Architecture for IMT-2000. What are the general
requirements for IMT 2000? [9]
b) What
are the key features of IS-95 CDMA System? Comment on the capability
of CDMA systems. [9]
January-2008 [0]
Chapter-7:
Wireless Local Area Networks (WLAN) : IEEE 802.11
January-2004 [22]
1.
c) How
does IEEE 802.11 solve the hidden terminal problem? [4]
6.
b) What
are the basic differences between wireless WANs and WLANs and what
are the common features? Consider mode of operation, administration,
frequencies, capabilities of nodes, services and national
/internatlonal regulations for comparison. [9]
7.
b) What
are advantages and problem of forwarding mechanisms in ad hoc
networks regarding security, power saving and network stability?
[9]
July-2004 [18]
3.
a) What
is the difference between a LAN and a PAN? Why is 802.11
inappropriate for a PAN? [3]
b) The
hidden-node problem is specific to wireless networks and no such
problem exists in wired LANs. Why? [2]
c) What
is narrow-band interference? Why is this to be avoided? What are the
two spreading techniques in 802.11 to avoid this? Briefly explain how
each of them work. Mention the modulation scheme used by each. Draw
the transmit spectrum before and after spreading for each of the two
techniques. [10]
d) In
an 802.11 system implementing CSMA/CA, suppose the physical layer
header size is H and the MAC/Link layer header size is M. Further, a
stop-and-wait protocol is used at the link layer, with the
acknowledgement packet size being A (including all headers). The size
of RTS and CTS packets (including all headers) are Rand C
respectively. For a MAC-level payload size of P, what is the
throughput achieved as a fraction of the raw physical layer
throughput? (Assume that all portions of the packet and the headers
are all transmitted at the same speed). [3]
January-2005 [13]
1.
g) Name
four major transmission techniques considered for WLAN standards and
give the standard activity associated with each of them.
[4]
3.
b) What
are the advantages and problems of forwarding mechanisms in adhoc
networks regarding security, power saving and network stability?
Describe briefly infrastructure requirements of adhoc networks.
[9]
July-2005 [14]
6.
a) Discuss
the working of adhoc WLANs. Under what circumstances ad-hoc networks
are preferred over Infrastructure WLAN? [9]
8.
b) Write
short notes on any two topics
ii) FHSS
vs. DSSS. [5]
January-2006 [4]
1.
g) Draw
and explain the wireless LAN architecture and also explain the terms
infrastructure mode and Adhoc mode. [4]
July-2006 [8]
1.
b) What
are the benefits of spread spectrum? What is frequency-hopping spread
spectrum? [4]
e) If
a computer is connected to a wireless LAN then it can communicate
with the Computers in wired LAN. Is the statement true? Justify by
giving reasons. [4]
January-2007 [10]
1.
d) What
is the difference between a LAN and a PAN? Why is 802.11
inappropriate for a PAN? [4]
5.
a) Why
do we need different MAC schemes for wireless LANS? Explain briefly
the hidden and exposed terminal problem associated with CSMA/CD.
[6]
July-2007 [13]
1.
a) In
context of Wireless Local Area Network give difference between ad-hoc
Wireless LAN and Infrastructure Wireless LAN. [4]
6.
a) Explain
the operation of MACAW protocol in WLANS. [9]
January-2008 [29]
1.
b) Differentiate
between Direct Sequence and Frequency Hopping spread spectrum
techniques. [4]
f) Discuss
the advantages and disadvantages of Ad-Hoc Networks. [4]
2.
b) Discuss
the advantages of WLAN. What are its disadvantages? What are design
goals for WLANS? [6]
5.
c) What
are the limitations in wireless networking? Discuss the security
issues in wireless networks. [6]
7.
a) Explain,
how MACAW protocol is operated in WLANS? [9]
Chapter-8:
Wireless Application Protocol (WAP)
January-2004 [18]
5.
a) What
Is the fundamental difference between WML and HTML? Why is this
difference important with respect to hand held devices?
[10]
b) What
are the primary goals of the WAP Forum efforts and how are they
reflected In the WAP protocol architecture? In which situation is WTP
not used? What are the disadvantages of implementing TCP/IP directly
over the mobile network? [8]
July-2004 [8]
1.
a) How
can a Bluetooth network have more than 8 nodes? Draw such a network
with 10 nodes and clearly mark the different nodes and parts of the
network. [4]
b) What
is the functionality of the WAP gateway? Why is this functionality
required? Draw a simple diagram showing how the WAP gateway
interfaces with wireless devices. [4]
January-2005 [24]
3.
a) Explain
WAP stack. Prove that WAP session protocol and WAP transaction
protocol over UDP conserves bandwidth as compared to TCP over IP.
[9]
4.
b) How
Internet may be supported on mobile links. Draw the architecture and
functional components of mobile IP. Describe data transfer from a
mobile node to a fixed node and vice-versa. [9]
7. Write
short notes on
d) Wireless
markup language. [6]
July-2005 [22]
1.
b) What
is the fundamental difference between WML and HTML? [4]
g) What
are the important functions of a WAP Gateway? [4]
5.
b) Why
does WAP define its own security layers and does not rely on the
security provided by the mobile phone network? Discuss the important
functions WSP and WAE. [9]
8.
b) Write
short notes on any two topics
iii) Blue-tooth
Protocol stock [5]
January-2006 [9]
7.
a) Draw
and explain the WAP network configuration. Also discuss the WAP
protocol stack. [9]
July-2006 [24]
5.
a) What
is mobile IP? Draw & describe the mobile IP architecture and its
functional components. [12]
6.
b) Explain
each of the following in detail with reference to WAP:
i) Wireless
Datagram Protocol
ii) Wireless
Transaction Protocol
- Wireless Session Protocol [6]
7. Write
short notes on the following:
a) Blue
tooth Protocol stack [6]
January-2007 [21]
1.
a) Why
do not other RF (Radio Frequency) devices interfere with Bluetooth
Devices? [4]
b) How
does a WAP Gateways act as a bridge between the mobile world and the
Internet? [4]
3.
b) What
is mobile IP? Explain with the help of a neat diagram how a mobile
user remains on line irrespective of his current position.
[9]
7.
a) Explain
briefly the types of links available with Bluetooth network.
[4]
July-2007 [19]
1.
c) What
are Wireless Application Protocol (WAP) gateway and its main
functions? [4]
5.
b) Wireless
Markup Language (WML) is optimized for limited capability devices and
networks. Describe WML constrains, features and document model?
[6]
6.
b) Bluetooth
is aimed for ad-hoc network with a very limited coverage and without
need for an infrastructure. Explain its Physical and Medium Access
Control Layers. [9]
January-2008 [12]
1.
d) What
is a Bluetooth technology? Discuss the different layers that
Bluetooth uses. [4]
6.
b) Differentiate
between:
i) Wireless
Datagram Protocol and Wireless Transaction Protocol
ii) Wireless
Session Protocol and Wireless Application Environment [8]
Chapter-9:
Wireless in Local Loop (WLL)
January-2004 [9]
6.
a) Describe
four major technologies for WLL system. What are the advantages and
disadvantages of these approaches? What are the benefits of using
15-95 CDMA technology for WLL? [9]
July-2004 [0]
January-2005 [6]
7. Write
short notes on
b) Wireless
in Local Loop. [6]
July-2005 [5]
8.
b) Write
short notes on any two topics
iv) WLL
Architecture [5]
January-2006 [0]
July-2006 [12]
3.
b) Discuss
the deployment issues with Wireless Local Loop (WLL). Explain
Satellite based technology for WLL Systems. [12]
January-2007 [7]
7.
c) What
are the factors that govern use and reuse of spectrum for WiLL? How
does modulation efficiency influence use and reuse of spectrum?
[7]
July-2007 [4]
1.
b) What
are the benefits of using Wireless Local Loop (WLL) Technologies in
broadband wireless access radio in loop? [4]
January-2008 [0]
Chapter-10:
VSAT systems and Networks Security
January-2004 [4]
1.
d) Why
does VSAT operate at slow data rates? [4]
July-2004 [22]
1.
f) Why
is security in a wireless network a greater concern than in wired
networks? Describe what is meant by authentication and point out how
is it different from data protection through encryption?
[4]
6.
a) What
is a VSAT? What are its two main modules in installation and their
functionalities? What are some advantages of using a VSAT?
[6]
b) Depict
the star topology of VSAT architecture in a simple diagram. Explain,
how the latency of communication between two VSAT nodes could be high
in this configuration. For what kinds of applications is this
inappropriate? [4]
c) How
does a mesh topology differ from a star topology? What is its
advantage over a star topology? [2]
d) What
is the main difference between TDMA and DAMA access methods for
VSATs? Which is better in terms of cost and why? [3]
e) Explain,
how VSATs can be used for one-way data systems (only the downlink).
For what application is this useful and why? [3]
January-2005 [15]
4.
a) What
are four aspects of Network security? Explain why public key
encryption requires fewer keys than secret key encryption. Given two
prime numbers p= 37 and q=23, define the private and public key by
soliciting appropriate value of the number e. [9]
7. Write
short notes on
e) VSAT
Access Schemes. [6]
July-2005 [4]
1.
e) Which
topology is generally deployed by VSATs and why? [4]
January-2006 [4]
4.
b) What
is VSAT? Give the components of VSAT systems. [4]
July-2006 [12]
4.
c) What
are the security requirements of wireless networks? [6]
5.
b) What
is VSAT? What are the services supported by VSAT networks?
[6]
January-2007 [16]
6.
a) Why
is TDM/TDMA technology widely used in most of the VSATs installed
globally? How can the frequency carrier be assigned between any two
VSATs on a demand basis? [6]
c) Explain
how VSATs can be used for one-way data systems (only the downlink).
For what application is this useful and why? [3]
7.
b) Explain
why public key encryption requires fewer keys than secret key
encryption. Given two prime numbers p= 37 and q=23, define the
private and public key by soliciting appropriate value of the number
e. [7]
July-2007 [13]
1.
g) What
are the basic problems which need to be addressed in VSAT networks?
[4]
7.
b) Very
Small Aperture Terminal (VSAT) in a satellite communication functions
is an overhead wireless repeater station that provides a microwave
communication link between two geographically remote sites. Specify
the operation of VAST networks. Give suitable examples.
[9]
January-2008 [10]
6.
a) Discuss
the advantages and disadvantages of VSAT networks. Explain the
operation of VSAT. [10]
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