Assignment 1.

MANET – CS 1424
Submitted by – Muskan gupta Scholar ID – 17-1-5-050
Date of submission – 10th October 2020 Contact Number - 7742438480

1) (a) Question: How are laptops (wireless device) connected to Internet?

Answer: Via wireless access points
Reference: Page 14 of paper: Mobile ad hoc networking: imperatives and
challenges.

(b) Question: What are wireless sensor networks?

Answer: A sensor network is composed of a large number of small sensor nodes
which are typically densely deployed inside the area in which a phenomenon is being
monitored. Wireless ad hoc networking techniques constitute the basis of sensor
networks.
Reference: Page 14 of paper: Mobile ad hoc networking: imperatives and
challenges.

(c) Question: What are disadvantages of Infrastructure-based networks?

Answer: Many a times, the user requiring network connection is not present in the
geographic location, which is more prominent in rural areas and abrupt geography
where the device installation might become a tedious task. Also, it also takes a lot of
time and resources (cost, equipment, etc.) to setup the network, adding more issue to
installations. This becomes huge challenges ahead of Infrastructure-based networks.
Reference: Page 14 of paper: Mobile ad hoc networking: imperatives and
challenges.

(d) Question: Explain the growth of mobile devices and hence, the growth of network
connections.
Answer: With the advancement of time and technology, not only that the mobile
devices are getting cheaper, smaller, more powerful and convenient, but also, they run
more network services and applications which fuel the explosive growth of mobile
computing equipment market.
Mobile users can use their cellular phone to check e-mail, browse internet, portable
systems can be used anywhere from airports to coffee shop or any local shop. They
are today used to pay bills, book tickets, find your route via GPS, and also to store and
exchange files and memories. In fact, with such advancements, people can even work
from home by attending conferences and webinars virtually and classes can be taken
over internet.
Among all the applications and services run by mobile devices, network connections
and corresponding data services are without doubt the most demanded service by the
mobile users. In this way, not only can mobile nodes communicate with each other,
but can also receive Internet services through Internet gateway node, effectively
 extending Internet services to the non-infrastructure area. As the wireless network
continues to evolve, these ad hoc capabilities are expected to become more important,
the technology solutions used to support more critical and significant future research
and development efforts can be expected in industry and academy, alike.
Reference: Page 13,14 of paper: Mobile ad hoc networking: imperatives and
challenges.

(e) Question: GPS stands for

Options: [i] Global Placement Software
[ii] Global Positioning System
[iii] General Positioning System
[iv] Global Positioning Software
Answer: [ii] Global Positioning System
Reference: Page 14 of paper: Mobile ad hoc networking: imperatives and
challenges.

2) (a) Question: What is a GPS?

Answer: satellite-based system to provide easy and accurate positioning
information anywhere on earth.
Reference: Page 16 of paper: Mobile ad hoc networking: imperatives and
challenges.

(b) Question: What is ad hoc mobile network?

Answer: An ad hoc mobile network is a transient network formed dynamically by
a collection of arbitrarily located wireless mobile nodes without the use of existing
network infrastructure. This is also referred to as spontaneous networking.
Reference: Page 17 of paper: Mobile ad hoc networking: imperatives and
challenges.
(c) Question: Explain the role of ambient intelligence in 4G wireless evolution.
Answer: 4G wireless evolution primarily aims at providing pervasive computing
environment that support users in accomplishing their tasks, access information or
communicate with others anytime, anywhere and from any device without having a
much of change in user but by exploiting technologies. This philosophy is the basis of
Ambient Intelligence concept, which is the integration of digital devices and networks
into everyday environment, rendering accessible through easy interactions. It places
the user at the centre of information society.
 Reference: Page 15 of paper: Mobile ad hoc networking: imperatives and
challenges.

(d) Question: List out the features of 4G and explain each in brief.
Answer: Following are the features of 4G:
o Network integration: 4G networks are touted as hybrid broadband
networks that integrate different network topologies and platforms.
o All IP networks: 4G starts with the assumption that future networks
will be entirely packet-switched, using protocols evolved from
those in use in today’s Internet.
o Lower cost and higher efficiency: 4G IP-based systems will be
cheaper and more efficient than 3G. Equipment costs are expected
to be four to ten times lower than equivalent circuit switched
equipment for 2G and 3G wireless infrastructures. An open
converged IP wireless environment further reduces costs for
network build-out and maintenance.
o Ultra-high speed and multimedia applications: They provide speed
up to 100Mbps. This leap in provided bandwidth allows users to
even watch TV, browse internet and have real time streaming.
o Location intelligence: Many technologies such as GPS, E-OTD, etc
are helping to have location accuracies which is a high requirement
for present adaptabilities in locations and applications of user.
Reference: Page 15,16 of paper: Mobile ad hoc networking: imperatives and
challenges.

(e) Question: Which of the following CANNOT be well received inside buildings.
Options: [i] Ultrasound
[ii] Radio
[iii] GPS signals
[iv] Infrared
Answer: [iii] GPS signals
Reference: Page 17 of paper: Mobile ad hoc networking: imperatives and
challenges.

3) (a) Question: Which is the largest-scale implementation of mobile wireless multi-hop

packet radio network implemented by US Army?
Answer: Tactical Internet (TI)
Reference: Page 18 of paper: Mobile ad hoc networking: imperatives and
challenges.
 (b) Question: What is multi-hop in ad hoc networking?
Answer: Each node will be able to communicate directly with any other node that
resides within its transmission range. For communicating with nodes that reside
beyond this range, the node needs to use intermediate nodes to relay the messages
hop by hop. This is known as Multi-hop.
Reference: Page 18 of paper: Mobile ad hoc networking: imperatives and
challenges.

(c) Question: What traditional problems if wireless communications and wireless

networking is inherited by ad hoc wireless networks?
Answer: Following issues are encountered:
• the wireless medium has neither absolute, nor
readily observable boundaries outside of which
stations are known to be unable to receive network
frames;
• the channel is unprotected from outside signals;
• the wireless medium is significantly less reliable
than wired media;
• the channel has time-varying and asymmetric
propagation properties;
• hidden-terminal and exposed-terminal phenomena
may occur
Reference: Page 19 of paper: Mobile ad hoc networking: imperatives and
challenges.
(d) Question: Draw a simple MANET architecture. List out the various constraints and
characteristics of an ad hoc network.
Answer:
 The research activities can be grouped based on layered approach into the following
areas,
1. Enabling technologies
2. Networking
3. Middleware and Applications
Issues faced:
o Autonomous and infrastructure-less. Works in peer to peer mode.
o Multi-hop routing. Every node act as router to forward message packets
o Dynamically changing network topologies.
o Variation in link and node capabilities as each device is different.
o Energy constrained operations as operates on batteries.
o Network scalability.
Reference: Page 19,20 of paper: Mobile ad hoc networking: imperatives and
challenges.

(e) Question: DARPA Packet Radio Network (PRNet) is inspired by efficiency of:
Options: [i] Packet switching
[ii] Multi-hop
[iii] static sharing of broadcast
[iv] Circuit switching
Answer: [i] Packet switching
Reference: Page 17 of paper: Mobile ad hoc networking: imperatives and
challenges.

4) (a) Question: Which technologies constitute the Enabling technologies for ad hoc
networking?
Answer: BAN, PAN and LAN. (Body, Personal and Local Area Network)
Reference: Page 20 of paper: Mobile ad hoc networking: imperatives and
challenges.

(b) Question: What are the main standards for ad hoc wireless network and what ranges
do they cover?
Answer: IEEE 802.11 standard for WLANs – for larger scale, implements single-
hop WLAN ad hoc network which can be extended to several sq. kms; and Bluetooth
– for small areas, devices inside the circle of 10m radius.
Reference: Page 21 of paper: Mobile ad hoc networking: imperatives and
challenges.
 (c) Question: Explain TX_range, PCS_range and IF_range.
Answer: TX-range: TX_range is the range (with respect to the transmitting station)
within which a transmitted packet can be successfully received. The transmission
range is mainly determined by the transmission power and the radio propagation
properties.
PCS_range: Physical Carrier Sensing Range (PCS_range) is the range (with
respect to the transmitting station) within which the other stations detect a busy
channel.
IF_range: Interference Range (IF_range) is the range within which a station in
receive mode will be interfered with by a transmitter, and thus suffer a loss. More
precisely, a transmitting station A can interfere with a receiving station B if A is
within the B interference range.
Reference: Page 25 of paper: Mobile ad hoc networking: imperatives and
challenges.
(d) Question: Explain the mechanism of Bluetooth and significance of Bluetooth in
today’s world.
Answer: The Bluetooth technology is a de-facto standard for low-cost, short-range
radio links between mobile PCs, mobile phones, and other portable devices. A
Bluetooth unit, integrated into a microchip, enables wireless ad hoc communications,
of voice and data between portable and/or fixed electronic devices like computers,
cellular phones, printers, and digital cameras. Due to its low cost, low power
consumption and industry-wide support, it has been embedded in almost all consumer
electronic devices.
The Bluetooth system can manage a small number of low-cost point-to-point, and
point to multi-point communication links over a distance of up to 10 m with a
transmit power of less than 1mW. It operates in the globally available unlicensed
ISM (industrial, scientific, medical) frequency band at 2.4 GHz and applies frequency
hopping for transmitting data over the air using a combination of circuit and packet
switching. From a logical standpoint, Bluetooth belongs to the contention-free token-
based multi-access networks. Into a Bluetooth network, one station has the role of
master, and all other Bluetooth stations are slaves. The master decides which slave is
the one to have the access to the channel. More precisely, a slave is authorized to
deliver a single packet to the master only if it has received a polling message from the
master. The units that share the same channel (i.e., are synchronized to the same
master) form a piconet, the fundamental building block of a Bluetooth network. A
piconet has a bit rate of 1 Mbit/s that represents the channel capacity including the
overhead introduced by the adopted protocols, and polling scheme. A piconet contain
a master station, and up to seven active (i.e., participate in data exchanging) slaves,
contemporarily.
A piconet constitutes a single-hop Bluetooth adhoc network. Multi-hop Bluetooth
networks can be obtained by interconnecting several piconets. The Bluetooth
specification defines a method for piconet interconnection: the scatternet. In this way,
multiple devices can be connected using an ad hoc wireless networking.
 Reference: Page 22,23 of paper: Mobile ad hoc networking: imperatives and
challenges.

(e) Question: Fill in the blanks. On increasing transmission range, hidden-station

problem occurs _____ frequently, while the exposed station problem becomes _____
important as the TX_range identifies the area affected by a single transmission.
Options: [i] more, more
[ii] more, less
[iii] less, less
[iv] less, more
Answer: [iv] less, more
Reference: Page 25 of paper: Mobile ad hoc networking: imperatives and
challenges.

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