Delivered Guest Talk in Faculty Development Programme held on 27th July 2017 @BVICAM New Delhi

Adhoc Networks & its Related
Empirical Research Directions
Dr. Umang
Institute of Technology & Science
Email: singh.umang@rediffmail.com

Introduction
• Computer Network is an interconnected
collection of independent computers which aids
communication.
• Good Communication Medium
– Sharing of Available resources
– Improved reliability of services
– Cost effectiveness
• Two major components
– Distributed Applications
– Networking Infrastructure

Wireless Network in Brief
• Computer networks that are not connected by
wires(Cables, Fibers etc.)of any kind.
• It enables enterprises to avoid the costly
process of introducing cables into buildings or
as a connection between different equipment
locations.
• The basis of wireless systems are radio waves,
an implementation that takes place at the
physical level of network structure.
Src: https://www.techopedia.com/definition/26186/wireless-network

WIRELESS NETWORKS DIVISION
• Industry to develop, deploy, and promote
emerging technologies and standards that will
dramatically improve the operation and use of
wireless networks.
Src: https://www.nist.gov/ctl/wireless-networks-division

Classification of Wireless Network

Cellular Networks
• Network is distributed over land areas called cells,
each served by at least one fixed-location transceiver,
known as a cell site or base station.
• This base station provides the cell with the network
coverage which can be used for transmission of
voice, data and others.
• A cell might use a different set of frequencies from
neighboring cells, to avoid interference and provide
guaranteed service quality within each cell.

Wireless Sensor Network
• It is collection of nodes, where each node is connected to one
(or sometimes several) sensors.
• Sensor network node consist of: a radio transceiver with an
antenna , a microcontroller, an electronic circuit for
interfacing with the sensors and an energy source, usually
a battery .

Wireless Mesh Network
• Rich interconnection among devices or nodes.
• consist of mesh clients, mesh routers and gateways.
• Mobility of nodes is less frequent. In case of high,
more time consumption in updating routes rather
than Data Delivery.
• Low-mobility centralized form of wireless ad hoc
network.

9
MANET – Mobile Ad hoc Networks
Mobile ad hoc network is “a transitory association [1-9] of mobile
nodes which do not depend upon any fixed support infrastructure.
Connection and disconnection is controlled by the distance among
nodes and by willingness to collaborate in the formation of cohesive,
albeit transitory community.”
Communication is done through wireless links among mobile hosts
through their antennas.

Delivered Guest Talk in Faculty Development Programme held on 27th July 2017 @BVICAM New Delhi

MANET – Mobile Ad hoc Networks
A
CB
D
- Mobility - Self Forming and healing - No Infrastructure
- Highly Dynamic - Independent of public infrastructure - Peer to Peer

12
Paradigm of Mobile ad hoc networks
• Formation of Dynamic Topology
• Bandwidth Constraints
• Energy Constrained Operation
• Limited Physical Security
• Autonomous transitory association of mobile nodes
• Possibly uni-directional links
• Constrained resources like Battery power, wireless transmitter range
• Network partitions due to frequent node movement
Significant examples:
Establishing communication for emergency or
rescue operations, disaster relief efforts and
military networks.
Mobility & Traffic
Significant Factor

Applications of MANETs
Tactical Operations
 Military
 Automated Battlefield
Collaborative & Distributive Computing
 Conferences
Emergency Operations
 Search & Rescue
Crowd Control
 Disaster Scenario
Sensor Based Applications
 Weather Monitoring
Entertainment
 Games

Emergency and Disaster Scenario(1)

Emergency and Disaster Scenario(2)

Difference between WSN and MANETs
Parameter
Used
WSN WMANETs
Important
Components
Sensing Ability
Communicating Part,
Processing Part
Communicating and Processing
Part “No Sensing Part”
Size Small Larger
Power
Capacity
Small Batteries Large Batteries
Cost Cheaper Expensive Comparatively
Density High Low
Redundancy High Low
Resources Limited like Memory
and Processing
Capability
Big Memory Size
Higher Processing Capability
Transmission
Range
Small Large

17
Routing
“To find and maintain routes between
nodes in a dynamic topology with
possibly uni-directional links, using
minimum resources”.
• Each node in this network must be able to
take care of routing of the packets and this is
the domain of ad-hoc routing. In routing
process, a route between source and
destination may consist of two or more
intermediate nodes.
• Route finding and maintenance is very
crucial problem due to rapid changes in
network topology
• Ad hoc routing protocols make routing
decisions based on individual node mobility .
Kinds of Routing
TABLE DRIVEN ROUTING
DSDV routing* (CGSR)
OLSR Routing
DSDV, LSR,GSR
ON DEMAND ROUTING
AODV routing*
DSR
TORA (multi-path) (hybrid)
HYBRID ROUTING
Zone Routing Protocol
(hybrid approach)
Geographical Routing (LB)
Multipath Routing
Energy-conserved routing
Secure routing

Research Issues in MANETs(1)
• The MAC protocol design should be fully
distributed involving minimum control over
head, synchronization(Usage of scarce
resources such as bandwidth & battery
power).
• MAC protocol should be able to overcome
the effect of collisions due to Hidden Terminal
Problem, Control Packets used for
synchronization., exposed terminal problem.
Designing Issues in MANETs

Research Issues in MANETs(2)
• Mechanism should attempt to minimize the
delay.
• Ability to provide an equal or weighted share
of the bandwidth to all computing nodes.
• Mechanism for throughput enhancement
– Minimize the occurrence of collisions
– Maximize Channel Utilization
– Minimizing Control Overhead
Designing Issues in MANETs

20
Research Challenges in Adhoc Networks

Research Issues in MANETs
•Medium Access Scheme
Distributed Operations
•Synchronization
•Hidden Terminals
•Exposed Terminals
•Throughput
•Access Delay
•Fairness
•Real Time Traffic Transport
•Resource Reservation
•Ability to measure resource
availability
•Capability for power
control
•Use of Directional
Antennas
• Routing
•Mobility
• Bandwidth Constraint
• Error Prone and Shared Channel
• Location dependent Contention
• Resource Constraint
Battery Power, Buffer Storage
Characteristics for Efficient Routing
Minimum Delay
Quick Route Reconfiguration
Loop Free Routing
Distributed Routing Approaches
Minimal Control Overhead
Security & Privacy
Support for Time sensitive Traffic
QoS (Jitter, Delay, Bandwidth, PDR, Throughput)
Others Issues
•Multicasting
•Reliable Connection
oriented TCP Protocol
•Security (Attacks, Resource
Consumption, Information Disclosure, Host
Impersonation etc.)
•Energy Management

22
Research Challenges
• In ad hoc networks, requirement of efficient routing has
been a complex problem due to lack of fixed infrastructure.
• The mobility of ad hoc nodes in routing imposes limitations
on their power capacity, bandwidth, as well as their
transmission range.
• Performance evaluation of ad hoc routing protocols based on
routing metrics is another challenging issue.
Cont’d…

Research Problems(Still Unexplored)
• Current simulation use fixed environment, where as real life
situations are practically random in nature.
• To study various mobility model to create random scenarios.
• Requirement of effective and efficient mobility management with
respect to specific application.
• Develop routing protocol which will consider the concept of power
as one of deciding factor in route selection.
• Develop a security solution that is embedded into possibly every
component in the network.
• To explore methods to optimally manage resources.
• Develop routing protocol which will evaluate presence of nodes in
static as well as dynamic scenario.

VANETs : An Overview of its Challenges

VANETs(Vehicular Adhoc Networks)
• Subclass of MANETs
• to provide communications
among nearby vehicles and
between vehicles and nearby
roadside equipment.
• Needs road related
information in advance for
maintaining significant
computing, communication,
and sensing capabilities.
Figure 1 VANETs system domains

Challenges in VANETs
• Safety
• Traffic Management
• Internet Services

Research Problems(Still Unexplored)
• Securing network transmissions without
securing the routing protocols is not sufficient.
Therefore, in VANET network with security
needs, there must be two security systems:
• One to protect the data transmission.
• One to make the routing protocol secure.

Flying Adhoc Networks & its Related
Research Issues

UAV
• Unmanned Air Vehicles
• Driverless Aircraft
• Remote Control by human operator or
onboard computers.
• Collection of Sensors, Actuators, Computing
Power, Communication Link, Remote Control-
Data Link, Recorder, Energy Supply

Flying Adhoc Networks
• It is group of Unmanned Air Vehicle(UAV) is
communicating with each other with no need to
access point, but at least one of them must be
connected to a ground base or satellite.
• Like as Autopilot.
• Known as Air bone Adhoc Networks.
• Reliable Protocol
– Two Factors
• Mobility Model
• Traffic Pattern

FANETs
• FANETs are new form of MANETs in which the
nodes are UAVs.
• Single UAV Systems cannot form a FANET
which is valid only for Multi UAV Systems.
• The UAV Communication must be realized
with the help of an ad hoc network between
UAVs then it will form FANETs.
• E.g. Aerial Robot Team, Aerial Sensor Network

Overview
MANET-VANET-FANET
FANETs
Moves on fly
UAVs Moves on Predetermined Path
Global Path Plans Preferred
Flight Plan is not Predetermined
In case of predefined flight plan ,if
environmental change , Flight plan may
be recalculated …

Major Challenge
• Size
• Coordination among Nodes

Research Issues in FANETs
• Routing: Existing MANETs routing protocols do not
satisfy the FANET requirements.
• There is need to develop New routing algorithm that
can support peer to peer communication and traffic
management which is still an open issue.
• There is need to develop Reliable environment in
dynamic fashion.
• Due to transmission of fast sender and multiple
sender, the receiver may be overloaded. So Flow
control is an important issue for heterogeneous
environment.

Research Issues in FANETs
• There is need to develop efficient transport
layer protocol which needs to fulfill
multimedia application reliability
requirements including its performance based
requirements(Delay, Bandwidth, jitter etc.).
• There is need to refine Mobility Models as
per FANET requirements.

Applications
• Search & Rescue Operations
• Managing Wildfire
• Border Surveillance
• Relay
• Wind Estimation
• Disaster Monitoring
• Remote Sensing
• Traffic Monitoring

Simulator & Emulator
• A Simulator is a less complex application that
simulation internal behavior of a device, but
does not emulate hardware and does not
work over the real operating System.
• An Emulator is an application the emulates
real mobile device software, hardware and
operating systems allowing us to test and
debug our application.

IMUNES
• Lightweight
• Complex network topologies
• Gigabit speeds
• Scalable Architecture for Real Time Experiments
• Open source and free
http://imunes.net/

Marionnet
• Marionnet is a virtual network laboratory: it allows
users to define, configure and run complex computer
networks without any need for physical setup.
• GNU/Linux host machine is required to simulate a
whole Ethernet network complete with computers,
routers, hubs, switches, cables, and more.
• Support is also provided for integrating the virtual
network with the physical host network.
• http://www.marionnet.org/site/index.php/en/

Mininet
• Software Defined Networking technologies.
• Mininet is most useful to researchers who are
building SDN controllers and need a tool to
verify the behavior and performance of SDN
controllers.
• Knowledge of the Python scripting language is
very useful when using Mininet.
• Excellent documentation
• http://www.mininet.org

NetKit
• Command-line based simulation tool that uses
user-mode Linux to create the virtual machines.
• A full Linux OS can run on each machine.
• It has good documentation and the project’s web
site has a long list of interesting lab scenarios to
practice, with documentation for each scenario.
• It also appears to be actively supported by a small
community and was last updated in 2011.
http://wiki.netkit.org/index.php/Main_Page

NS-3
• It is a discrete-event open-source network
simulator for Internet systems, used primarily
for research and educational use. NS-3 is a
complex tool that runs simulations described by
code created by users, so you may need
programming skills to use it.
• NS-3 can run real software on simulated nodes
using its Direct Code Execution feature.
• This allows researchers to test real software in a
discrete-event network simulation to produce
repeatable experiments.
https://www.nsnam.org/

OFNet
• It is a new software-defined network (SDN)
emulator that offers functionality similar to
the Mininet network emulator and adds some
useful tools for generating traffic and
monitoring Open Flow messages and
evaluating SDN controller performance.
• http://sdninsights.org

OpenStack all-in-one
• OpenStack simulator for students and
researchers interested in experimenting with
cloud systems.

2012 53
Network Simulator 2 Basics
© ITS, Mohan Nagar Gzb , prepared by Umang Singh
• Event driven simulation tool
• Useful in studying the dynamic nature of communication networks.
• It provides users with a way of specifying such network protocols and
simulating their corresponding behaviors.
• Established in 1989.
• It is based on REAL network simulator.
• In 1995 it was tested on VINT (Virtual Inter Network Testbed) testbed.
• Funded by DARPA (Defense Advanced Research Projects Agency (DARPA)), the VINT
project aimed at creating a network simulator that will initiate the study of different
protocols for communication networking.
• Currently NSF (National Science Foundation) is showing interest in the development of
this simulator.

2012 54
About ns2
NS2 is available on several platforms such as FreeBSD, Linux, SunOS Ubuntu, CentOS and
Solaris. NS2 also builds and runs under Windows.
NS2 source codes are distributed in two forms: the all-in-one suite and the component-wise.
The current all-in-one suite consists of the following main components:
• NS,
• Tcl/Tk,
• OTcl, and
• TclCL.
and the following are the optional components:
• NAM : NAM is an animation tool for viewing network simulation
traces and packet traces.
• Zlib : This is the required library for NAM.
• Xgraph : This is a data plotter with interactive buttons for
panning, zooming, printing, and selecting display options

2012 55
C++ & OTCL
•Ns2 set contains two sets of languages, namely C++ and OTcl.
• C++ is used for the creation of objects because of speed and efficiency and run
at backend for actual simulation.
• OTcl is used as a front-end to setup the simulator, configure objects and schedule
events because of its ease of use.

2012 56
Installation
Installing an All-In-One NS2 Suite on Unix-Based Systems
Download from
http://sourceforge.net/projects/nsnam/files/allinone/ns-allinone-2.34/
At command prompt:
tar -xzf ns-allinone-2.34.tar.gz
cd ns-allinone-2.34
./install
cd ns-2.34 ./validate
The following commands show how the all-in-one NS2 suite can be installed and
validated, respectively:
shell>./install
shell>./validate

2012 57
Programming in ns2:
My First Program
WAP to print “HELLO WORLD”.
Set ns [new Simulator]
$ns at 1 “puts “Hello World! “”
$ns at 1.5 “exit”
$ns run
Save hello.tcl

2012 58
My Second Program “Create topology”
#Create two nodes
set n0 [$ns node]
set n1 [$ns node]
#Create a duplex link between the nodes
$ns duplex-link $n0 $n1 1Mb 10ms DropTail
#Call the finish procedure after 5 seconds of simulation time
$ns at 5.0 "finish"
#Run the simulation
$ns run

2012 59
My Third Program “Create topology”
#Create a simulator object
set ns [new Simulator]
#Tell the simulator to use dynamic routing
$ns rtproto DV
#Open the nam trace file
set nf [open out.nam w]
$ns namtrace-all $nf
#Define a 'finish' procedure
proc finish {}
{ global ns nf
$ns flush-trace

2012 60
#Close the trace file
close $nf
#Execute nam on the trace file
exec nam –a out.nam & exit 0 }
#Create seven nodes
for {set i 0} {$i < 7} {incr i}
{ set n($i) [$ns node] }
#Create links between the nodes
for {set i 0} {$i < 7} {incr i}
{ $ns duplex-link $n($i) $n([expr ($i+1)%7]) 1Mb 10ms DropTail
}

2012 61
#Create a UDP agent and attach it to node n(0)
set udp0 [new Agent/UDP]
$ns attach-agent $n(0) $udp0
# Create a CBR traffic source and attach it to udp0
set cbr0 [new Application/Traffic/CBR] $cbr0
set packetSize_ 500 $cbr0
set interval_ 0.005 $cbr0 attach-agent $udp0
#Create a Null agent (a traffic sink) and attach it to node n(3)
set null0 [new Agent/Null]
$ns attach-agent $n(3) $null0

2012 62
#Connect the traffic source with the traffic sink
$ns connect $udp0 $null0
#Schedule events for the CBR agent and the network
dynamics
$ns at 0.5 "$cbr0 start"
$ns rtmodel-at 1.0 down $n(1) $n(2)
$ns rtmodel-at 2.0 up $n(1) $n(2)
$ns at 4.5 "$cbr0 stop"
#Call the finish procedure after 5 seconds of simulation time
$ns at 5.0 "finish"
#Run the simulation
$ns run

2012 63
X Graph
plot the bandwidth of two nodes connected through full duplex wired link.
#Create a simulator object
set ns [new Simulator]
#Open the output trace file
set f0 [open out0.tr w]
#Create 2 nodes
set n0 [$ns node]
set n1 [$ns node]
#Connect the nodes using duplex link
$ns duplex-link $n0 $n1 1Mb 100ms DropTail
#Define a 'finish' procedure
proc finish {} {
global f0
#Close the output files
close $f0
#Call xgraph to display the results
exec xgraph out0.tr -geometry 800x400 &
exit 0
}

2012 64
#Define a procedure which periodically records the bandwidth received by the
#the traffic sink0 and writes it to the file f0.
proc record {} {
global sink0 f0
#Get an instance of the simulator
set ns [Simulator instance]
#Set the time after which the procedure should be called again
set time 0.5
#How many bytes have been received by the traffic sinks?
set bw0 [$sink0 set bytes_]
#Get the current time
set now [$ns now]
#Calculate the bandwidth (in MBit/s) and write it to the files
puts $f0 "$now [expr $bw0/$time*8/1000000]"
#Reset the bytes_ values on the traffic sinks
$sink0 set bytes_ 0
#Re-schedule the procedure
$ns at [expr $now+$time] "record"
}
X Graph

2012 65
#Create three traffic sinks and attach them to the node n4
set sink0 [new Agent/LossMonitor]
#Start logging the received bandwidth
$ns at 0.0 "record"
$ns at 60.0 "finish"
#Run the simulation
$ns run
X Graph

Challenges of Network Simulator
• Scalability
• Reality

Related Network Simulator Links:
• http://www.brianlinkletter.com/open-source-
network-simulators/
• https://omnetpp.org/
• https://www.youtube.com/watch?v=so1Q5zY
LQx4

Adhoc Networks & its Related
Research Issues
End of Session-1

Delivered Guest Talk in Faculty Development Programme held on 27th July 2017 @BVICAM New Delhi

Delivered Guest Talk in Faculty Development Programme held on 27th July 2017 @BVICAM New Delhi

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Delivered Guest Talk in Faculty Development Programme held on 27th July 2017 @BVICAM New Delhi