Demo Question Bank

1. 2. Design Mobile
Computing Architecture
Question Bank
Swapnali Pawar
Question Bank

2. Swapnali Pawar
Unit 2
Design Mobile Computing Architecture
1.Theory Questions -
1. Explain Characteristics of Mobile Communication & Applications of Mobile
Communication
2. What are the Security Concerns Related to Mobile Computing?
3. What is Middleware & Gateway in Mobile Computing
4. What is Mobile IP? Explain in Detail with Diagram
5. Why we use Satellite in mobile Communication & what are types of
Satellite explain with diagram
6. Explain Simplified Reference Model for Mobile Communication.
2.MCQ Questions -
1.Which of the following are characteristics of Mobile Communication devices?
A. Fixed & Wired
B. Mobile & Wired
C. Fixed & Wireless
D. Mobile & Wireless
2.Desktop Computer is an example of Fixed & Wired Device
3.Laptops are example of Mobile & Wired Devices
4.Fixed & Wireless mode is used for Installing Networks
5.Mobile & Wireless mode has no cable restrictions

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6.Applications of Mobile Communication
Vehicles
Emergencies
Business
Replacement of wired networks
Infotainment and more
Location dependent services
Mobile and wireless devices
8.Features of Mobile Communication
High Capacity load balancing
Scalability
Network Management System
Role based Access Control
Roaming
Redundancy
Proper Security With Firewall
Switching
9.Advantages of Mobile Communication
Flexibility
Cost Effectiveness
Speed
Accessibility
Constant Connectivity
10.PDA provides example of Wireless & Portable Device

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11._______is lowest layer of communication system & is responsible for conversion of stream
of bits into signals
A.Application Layer
B.Physical Layer.
C.Network Layer
D.Datalink Layer
Ans-B
12.Datalink Layer is Responsible for______________
A.Transmission Error Correction
B.data streams Multiplexing
C.Synchronization
D.Converting Bit Streams
E.Medium Access
Ans-All Except D
13.Network Layer is Responsible for packet routing through networks or connection
establishment
14.Data link layer is responsible for point to point connection or point to multipoint connection
between 2 devices
A.True
B.False
15.Transport Layer is responsible for end to end connection
16.Application Layer
17.Security Concerns related to mobile Computing

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Confidentiality
Integrity
Availability
Legtimate
Accountability
18.Wireless Security Issues
DOS Attacks
Traffic Analysis
Evesdropping
Session Interception & Message Modification
Spoofing
Captured & retransmitted Message
Device Security Issues
Push Attacks
Pull Attacks
forced deAuthentication
Multi Protocol Communication
Mobility
Disconnections
19.Integrity means to protect unauthorized modification ,destruction or creation of information
20.High capacity load balancing means, when one access point is overloaded, the system will
actively shift users from one access point to another depending on the capacity which is
available.
21.Confidentiality
is used to prevent unauthorized users from gaining access to any particular user's critical and
confidential information

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22.Legitimate
This is used to ensure that only authorized, and legitimate users have access to the services
23.The denial of services or DOS attacks is one of the most common attacks of all kinds of
networks and especially in a wireless network. It prevents users from using network services
because the attacker sends a large amount of unnecessary data or connection requests to the
communication server. It causes a slow network, and therefore the users cannot get benefitted
from using its service
24.Traffic Analysis
Traffic analysis is used to identify and monitor communication between users. In this process,
the service provider listens the traffic flowing in the wireless channel to access the private
information of users affected by the attacker.
25.Mobility means Ability to move from One location to another location.
26.Types of Mobility-
1.User mobility
2.Device Mobility
26.Device portability means device moves with or without user eg-Mobile Phone
27.User mobility refers to user who has access to same or similar telecommunication services
at different places
28.Base Station consist of Radio Trans receiver & Interworking Unit
29.protocol is_____________
30.Mobile Devices that store sensitive data can be protected by means of_____
Ans=>Encryption

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31.Middleware is a software that provides link between seprate software applications and
common services and capabilities to applications
32.Middleware is Responsible for
A.to provide interaction with other services or applications
B.filter data
C.Make Application independent of network services
D.make application reliable and always available
33.Types of Middleware
Communication Middleware
Message Oriented Middleware
Object Oriented Middleware
Remote Procedure Call (RPC) Middleware
Database Middleware
Transaction Middleware
Embedded Middleware
Content-Centric Middleware
34.Message Oriented Middleware supports the receiving and sending of messages over
distributed applications
35.Object Oriented Middleware is also known as an object request broker.
36.Database Middleware provides direct access to databases and direct interaction with
databases
37.Gateways are required when the networks between the device and the middleware having
different set of protocol.

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38.Mobile IP
This is an IETF (Internet Engineering Task Force) standard communications protocol
designed to allow mobile devices' such as laptop, PDA, mobile phone, etc. users to move from
one network to another while maintaining their permanent IP Internet Protocol address.
39.Mobile Node (MN)
The mobile node is an end system or device such as a cell phone, PDA (Personal Digital
assistant), or laptop whose software enables network roaming capabilities.
40. Home Agent (HA)
The home agent provides several services for the mobile node and is located in the home
network. The tunnel for packets towards the mobile node starts at home agent.
41.The home agent maintains a location registry, i.e. it is informed of the mobile node's
location by the current COA (care of address).
42.The foreign agent can provide several services to the mobile node during its visit to the
foreign network.
43.Foreign agent can also provide security services because they belong to the foreign network
as opposed to the MN which is only visiting.
44.The Care- of- address defines the current location of the mobile node from an IP point of
view
45.There are two different possibilities for the location of the care of address:
Foreign Agent COA:
The COA could be located at the foreign agent, i.e. the COA is an IP address of the foreign
agent. The foreign agent is the tunnel endpoint and forwards packets to the MN. Many MN
using the FA can share this COA as common COA.

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Co-located COA:
The COA is co-located if the MN temporarily acquired an additional IP address which acts as
a COA. This address is now topologically correct, and the tunnel endpoint is at the mobile
node. Co-located address can be acquired using services such as DHCP. One problem
associated with this approach is need for additional addresses if MNs request a COA. This is
not always a good idea considering the scarcity of IPv4 addresses.
46.Home Network
The home network is the subset the MN belongs to with respect to its IP address.
47. Foreign network
The foreign network is the current subset the MN visits and which is not the home network.
48.The mobile IP process has following three main phases, which are:
1. Agent Discovery
2. Registration
3. Tunneling
49Agent Discovery
During the agent discovery phase the HA and FA advertise their services on the network by
using the ICMP router discovery protocol (IROP).
50. Registration
The main purpose of the registration is to inform the home agent of the current location for
correct forwarding of packets.
51.Tunneling
A tunnel is used to establish a virtual pipe for data packets between a tunnel entry and a tunnel
endpoint. Packets which are entering in a tunnel are forwarded inside the tunnel and leave the

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tunnel unchanged. Tunneling, i.e., sending a packet through a tunnel is achieved with the help
of encapsulation.
Tunneling is also known as "port forwarding" is the transmission and data intended for use
only within a private, usually corporate network through a public network.
52.Mobile IP is a communication protocol created by extending Internet Protocol, IP that
allows the users to move from one network to another with the same IP address. It ensures that
the communication will continue without user’s sessions or connections being
dropped.=>True
53.Home Address:
It is the permanent IP address assigned to the mobile node (within its home network).
54.Agent Discovery:
Agents advertise their presence by periodically broadcasting their agent advertisement
messages. The mobile node receiving the agent advertisement messages observes whether the
message is from its own home agent and determines whether it is in the home network or
foreign network.
55.Agent Registration:
Mobile node after discovering the foreign agent, sends registration request (RREQ) to the
foreign agent. Foreign agent in turn, sends the registration request to the home agent with the
care-of-address. Home agent sends registration reply (RREP) to the foreign agent. Then it
forwards the registration reply to the mobile node and completes the process of registration.
56.Tunneling:
It establishes a virtual pipe for the packets available between a tunnel entry and an endpoint.
It is the process of sending a packet via a tunnel and it is achieved by a mechanism called
encapsulation. It takes place to forward an IP datagram from the home agent to the care-of-
address. Whenever home agent receives a packet from correspondent node, it encapsulates the
packet with source address as home address and destination as care-of-address.
57.Route Optimization in Mobile IP:

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The route optimization adds a conceptual data structure, the binding cache, to the
correspondent node. The binding cache contains bindings for mobile node’s home address and
its current care-of-address.
58.A mobile node can request a reverse tunnel between its foreign agent and its home agent
when the mobile node registers.
59.A reverse tunnel is a tunnel that starts at the mobile node's care-of address and terminates
at the home agent
60.A communication satellite is a microwave repeater station in a space that is used for
telecommunication, radio and television signals.
61.Uplink frequency is the frequency at which ground station is communicating with satellite.
62.The satellite transponder converts the signal and sends it down to the second earth station,
and this is called Downlink frequency.
63.Which of the following are Advantages of Satellite?
The Coverage area is very high than that of terrestrial systems.
The transmission cost is independent of the coverage area.
Higher bandwidths are possible.
64.Which of the following are Disadvantages of Satellite?
Launching satellites into orbits is a costly process.
The bandwidths are gradually used up.
High propagation delay for satellite systems than the conventional terrestrial systems.
65 which of the following are Earth Orbits Types
Geo-synchronous Earth Orbit
Geo-stationary Earth Orbit

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Medium Earth Orbit
Low Earth Orbit
66.Geo-Stationary Earth Orbit Satellites are used for weather forecasting, satellite TV, satellite
radio and other types of global communications
67.Medium earth orbit (MEO) satellite networks will orbit at distances of about 8000 miles
from earth's surface
68.The LEO satellites are mainly classified into three categories namely, little LEOs, big
LEOs, and Mega-LEOs. LEOs will orbit at a distance of 500 to 1000 miles above the earth's
surface.
69.The High Earth orbit satellite is the only non-circular orbit of the four types.
70.Satellite Distance
Geo - 35,768km
MEO - 6000 to 20000km
LEO - 500 to 1500km
71.MEO satellites are similar to LEO satellites in the context of functionality
72.Three Geostationary satellites are enough for a complete coverage of almost any spot on
earth.
73.MEO satellites have a larger coverage area than Low Earth Orbit satellites.
_____________________
THANK YOU

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