Final Report Adhoc

7/31/2019 Final Report Adhoc

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Seminar Report

On

Ad Hoc

Networks

Submitted by:

Sachin Tyagi

2808332

B.tech(IT)-Final year


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TABLE OF CONTENT

TOPIC Page No.

Computer networks 3

Computer network properties 5

Ad hoc networks 8

characteristics 12

Limitations 13

Types of Ad hoc network 15

MANET 15

Wireless Sensor Network 18

Applications 20

Performance Issues 21

Refrences 22


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COMPUTER NETWORKS

A computer network, often simply referred to as a network, is a collection of hardware

components and computers interconnected by communication channels that allow sharing of

resources and information. Where at least one process in one device is able to send/receive

data to/from at least one process residing in a remote device, then the two devices are said to

be in a network. Networks may be classified according to a wide variety of characteristics

such as the medium used to transport the data, communications protocol used, scale,

topology, and organizational scope.

Communications protocols define the rules and data formats for exchanging information in a

computer network, and provide the basis for network programming. Well-known

communications protocols are Ethernet, a hardware and link layer standard that is ubiquitous

in local area networks, and the internet protocol suite, which defines a set of protocols for

internetworking, i.e. for data communication between multiple networks, as well as host-to-

host data transfer, and application-specific data transmission formats.

Simplified but worthwhile description of the uses of computer networks might be as follows:

Sharing of hardware: For example, several PCs might be networked together in a wired or

wireless local area network (LAN) to share a printer.

Sharing of information: Distributed databases, e-mail, the World Wide Web and so on are

examples of this. Here the sharing involves both LANs and wide area networks (WANs).


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Computer Network

Purpose of computer networks:

The primary purpose of a computer network is to share resources:

You can access data from one computer while sitting on another computer

You may have a computer that doesnt have a dvd player. In this case, you can place amovie disc on the computer that has the player, and then view the movie on a

computer that lacks the player

You may have a computer with a backup system but the other computer doesnt haveit. In this case, you can burn discs or make backups on a computer that has one of

these but using data from a computer that doesnt have a backup system

You can connect a printer (or a scanner, or a fax machine) to one computer and letother computers of the network print (or scan, or fax) to that printer.

You can create files and store them in one computer, then access those files from theother computer(s) connected to it.


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Computer networks properties:

Facilitate communications

Using a network, people can communicate efficiently and easily via email, instantmessaging, chat rooms, telephone, video telephone calls, and video conferencing.

Permit sharing of files, data, and other types of information

In a network environment, authorized users may access data and information stored

on other computers on the network. The capability of providing access to data and

information on shared storage devices is an important feature of many networks.

Share network and computing resources

In a networked environment, each computer on a network may access and useresources provided by devices on the network, such as printing a document on a shared

network printer. Distributed computing uses computing resources across a network to

accomplish tasks.

May be insecure

A computer network may be used by computer hackers to deploy computer viruses orcomputer worms on devices connected to the network, or to prevent these devices from

normally accessing the network (denial of service).

May interfere with other technologies

Power line communication strongly disturbs certain forms of radio communication,

A complex computer network may be difficult to set up. It may also be very costly toset up an effective computer network in a large organization or company.


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Different views of network:

Users and network administrators typically have different views of their networks. Users can

share printers and some servers from a workgroup, which usually means they are in the same

geographic location and are on the same LAN, whereas a Network Administrator is

responsible to keep that network up and running. A community of interest has less of a

connection of being in a local area, and should be thought of as a set of arbitrarily located

users who share a set of servers, and possibly also communicate via peer-to-peer

technologies.

Network administrators can see networks from both physical and logical perspectives. The

physical perspective involves geographic locations, physical cabling, and the network

elements (e.g., routers, bridges and application layer gateways) that interconnect the physical

media. Logical networks, called, in the TCP/IP architecture, subnets, map onto one or more

physical media. For example, a common practice in a campus of buildings is to make a set of

LAN cables in each building appear to be a common subnet, using virtual LAN (VLAN)

technology.

Both users and administrators will be aware, to varying extents, of the trust and scope

characteristics of a network. Again using TCP/IP architectural terminology, an intranet is a

community of interest under private administration usually by an enterprise, and is only

accessible by authorized users (e.g. employees). Intranets do not have to be connected to the

Internet, but generally have a limited connection. An extranet is an extension of an intranet

that allows secure communications to users outside of the intranet (e.g. business partners,

customers).


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Unofficially, the Internet is the set of users, enterprises, and content providers that are

interconnected by Internet Service Providers (ISP). From an engineering viewpoint, the

Internet is the set of subnets, and aggregates of subnets, which share the registered IP address

space and exchange information about the reachability of those IP addresses using the Border

Gateway Protocol. Typically, the human-readable names of servers are translated to IP

addresses, transparently to users, via the directory function of the Domain Name System

(DNS)

Hosts are sometimes further divided into two categories: clients and servers. Informally,

clients often tend to be desktop PCs or workstations, whereas servers are more powerful

machines. But there is a more precise meaning of a client and a server in computer

networking. In the so-called client/server model, a client program running on one end system

requests and receives information from a server running on another end system. This

client/server model is undoubtedly the most prevalent structure for Internet applications.

The Web, e-mail, file transfer, remote login (for example, Telnet), newsgroups, and many

other popular applications adopt the client/server model.


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AD HOC NETWORKS

Ad Hoc" is actually a Latin phrase that means "for this purpose." It is often used to describe

solutions that are developed on-the-fly for a specific purpose. In computer networking, an ad

hoc network refers to a network connection established for a single session and does not

require a router or a wireless base station.

An ad hoc network is a type of peer to peer wireless network mode where wireless devices

communicate with each other directly, without the aid of a Wireless Access Point (WAP)

device. Wireless networks typically depend on a base station or WAP device to manage and

direct the stream of data between wireless devices.

In an ad hoc setup, the network is built spontaneously as and when devices communicate with

each other. These devices should ideally be within close range of each other; however quality

of connection and speed of the network will suffer as more devices are added to the network.

The security of an ad hoc network is non-existent, as wireless security norms such as WAP2,

WAP, and WEP are not permitted in such direct networking.

For example, if you need to transfer a file to your friend's laptop, you might create an ad hoc

network between your computer and his laptop to transfer the file. This may be done using an

Ethernet crossover cable, or the computers' wireless cards to communicate with each other. If

you need to share files with more than one computer, you could set up a mutli-hop ad hoc

network, which can transfer data over multiple nodes.

Basically, an ad hoc network is a temporary network connection created for a specific

purpose (such as transferring data from one computer to another). If the network is set up for

a longer period of time, it is just a plain old local area network.


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An ad-hoc or short-live network is the network of two or more mobile devices connected to

each other without the help of intervening infrastructure. In contrast to a fixed wireless

network, an ad-hoc network can be deployed in remote geographical locations and requires

minimum setup and administration costs. Moreover, the integration of an ad-hoc network

with a bigger network-such as the Internet-or a wireless infrastructure network increases the

coverage area and application domain of the ad-hoc network. However, communication in an

ad-hoc network between different hosts that are not directly linked is an issue not only for

search and rescue operations, but also for educational and business purposes.

In the Windows operating system, ad-hoc is a communication mode (setting) that allows

computers to directly communicate with each other without a router.

Ad hoc networks


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Adhoc wireless network

This diagram illustrates use of a so-called ad hoc wireless setup in a home network.

Key Considerations - Using ad hoc Wi-Fi mode eliminates the need for a network router or

access point in a wireless home network. With ad hoc wireless, you can network computers

together as needed without needing to be in reach of one central location. Most people use ad

hoc Wi-Fi only in temporary situations to avoid potential security issues.

Optional Components - Networking an ad hoc layout for Internet access, printers, or game

consoles and other entertainment devices is not required for the rest of the home network to

function. Simply omit any of these components shown that do not exist in your layout.


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Why Adhoc wireless networking:

Technical side: wireless devices need to be connected. increased performance/cost ratio on devices . Internet compatible standards-based wireless systems.

Market side: mobile computing; wearable computing; military applications; disaster

recovery; robot data acquisition.

Characteristics of Ad-hoc network:

Autonomous (no infrastructure !). Wireless link based; (bandwidth constraint) Dynamic topology; (Due to movement or entering sleep mode). Rely on batteries for energy; (Power-constraint). Limited physical security. Dynamic topologies. Limited channel bandwidth. Variable capacity links.


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Limitations

All devices connecting via ad hoc wireless must possess a working Wi-Fi networkadapter. These adapters must be configured for "ad hoc" mode instead of the more

typical "infrastructure" mode.

Because of their more flexible design, ad hoc Wi-Fi networks are also more difficultto keep secure than those using central wireless routers / access points.

Ad hoc Wi-Fi networks support a maximum of 11 Mbps bandwidth, while other Wi-Fi networks may support 54 Mbps or higher.

Security challenges:

Lack of Infrastructure or centralized control Key management becomes difficult

Dynamic topology Challenging to design sophisticated & secure routing protocols

Communication through Radio Waves

Difficult to prevent eavesdropping

Vulnerabilities of routing mechanism Non-cooperation of nodes

Vulnerabilities of nodes.


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How to set up an ad hoc network at home:

In order to establish an ad hoc connection, you must have two or more personal computers or

laptops with wireless network interface cards. To establish an ad hoc connection on a home

computer, perform the following steps:

1. Click Start and then click Control Panel.2. Double-click the Network Connections icon.

3. Right-click your wireless network connection, and click Properties.4. The Wireless Network Connection Properties window appears. Click the WirelessNetwork Tab.

5. Click the Add button present under the Preferred networks section.6. The Wireless Network Properties window appears.7. Type a name for your network in the text field Network Name (SSID), present underthe tab Association.

8. Check both the The key is provided for me automatically and This is a computer-to-computer (ad hoc) network check boxes.

9. Click Ok to save the made changes. The Ad hoc network is now set up.


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TYPES OF AD HOC NETWORKS:

mobile ad-hoc networks (MANET)

wireless mesh networks (WMN)

MOBILE AD-HOC NETWORKS (MANET):

MANET is a collection of two or more devices or nodes or terminals with wireless

communications and networking capability that communicate with each other without the aid

of any centralized administrator also the wireless nodes that can dynamically form a network

to exchange information without using any existing fixed network infrastructure. And its an

autonomous system in which mobile hosts connected by wireless links are free to be

dynamically and some time act as routers at the same time. All nodes in a wireless ad hoc

network act as a router and host as well as the network topology is in dynamically, because

the connectivity between the nodes may vary with time due to some of the node departures

and new node arrivals. The special features of Mobile Ad Hoc Network (MANET) bring this

technology great opportunity together with severe challenge.

The set of application for MANETs can be ranged from small, static networks that are limited

by power sources, to large-scale, mobile, highly dynamic networks. On top of that, the design

of network protocols for these types of networks is face with multifaceted issue. Apart from

of the application, MANETs need well-organized distributed algorithms to determine

network organization, link scheduling, and routing.


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All the nodes or devises responsible to organize themselves dynamically the communication

between the each other and to provide the necessary network functionality in the absence of

fixed infrastructure or we can call it ventral administration, It implies that maintenance,

routing and management, etc. have to be done between all the nodes.

Mobile Ad hoc Network

Each device in a MANET is free to move independently in any direction, and will therefore

change its links to other devices frequently. Each must forward traffic unrelated to its own

use, and therefore be a router. The primary challenge in building a MANET is equipping each


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device to continuously maintain the information required to properly route traffic. Such

networks may operate by themselves or may be connected to the larger Internet.

MANETs are a kind of wireless ad hoc networks that usually has a routable networking

environment on top of a Link Layer ad hoc network.

The growth of laptops and wireless networking have made MANETs a popular research topic

since the mid 1990s. Many academic papers evaluate protocols and their abilities, assuming

varying degrees of mobility within a bounded space, usually with all nodes within a few hops

of each other. Different protocols are then evaluated based on measure such as the packet

drop rate, the overhead introduced by the routing protocol, end-to-end packet delays, network

throughput etc.

Types of MANET:

Vehicular Ad-hoc Networks (VANETs) are used for communication among vehiclesand between vehicles and roadside equipment. For example, a university bus system, if the

buses are connected. The buses travel to different parts of a city to pick up or drop off

students, and make an ad-hoc network.

Intelligent vehicular ad-hoc networks (InVANETs) are a kind of artificialintelligence that helps vehicles to behave in an intelligent manner during vehicle-to-vehicle

collisions, accidents, drunken driving etc.

Internet Based Mobile Ad-hoc Networks (iMANET) are ad-hoc networks that linkmobile nodes and fixed Internet-gateway nodes. In such type of networks normal adhoc

routing algorithms don't apply directly.


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WIRELESS SENSOR NETWORK:

A wireless sensor network (WSN) consists of spatially distributed autonomous sensors to

monitor physical or environmental conditions, such as temperature, sound, vibration,

pressure, humidity, motion or pollutants and to cooperatively pass their data through the

network to a main location. The more modern networks are bi-directional, also enabling

control of sensor activity. The development of wireless sensor networks was motivated by

military applications such as battlefield surveillance; today such networks are used in many

industrial and consumer applications, such as industrial process monitoring and control,

machine health monitoring, and so on.

Wireless sensor network

The WSN is built of "nodes"from a few to several hundreds or even thousands, where each

node is connected to one (or sometimes several) sensors. Each such sensor network node has

typically several parts: a radio transceiver with an internal antenna or connection to an

external antenna, a microcontroller, an electronic circuit for interfacing with the sensors and
http://en.wikipedia.org/wiki/File:WSN.svg


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an energy source, usually a battery or an embedded form of energy harvesting. A sensor node

might vary in size from that of a shoebox down to the size of a grain of dust, although

functioning "motes" of genuine microscopic dimensions have yet to be created. The cost of

sensor nodes is similarly variable, ranging from a few to hundreds of dollars, depending on

the complexity of the individual sensor nodes. Size and cost constraints on sensor nodes

result in corresponding constraints on resources such as energy, memory, computational

speed and communications bandwidth. The topology of the WSNs can vary from a simple

star network to an advanced multi-hop wireless mesh network. The propagation technique

between the hops of the network can be routing or flooding.

There are many benefits of this network, it includes:

Use to build a large-scale networks

Implementing sophisticated protocols

Reduce the amount of communication (wireless) required to perform tasks by distributed

and/or local precipitations.

Implementation of complex power saving modes of operation depending on the

environment and the state of the network


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APPLICATION OF AD HOC NETWORK:

1.Military battlefield. Military equipment currently is equipped with the state of the art

computer equipment. Ad hoc networking help the military with the commonplace network

technology to maintain information network between military personnels, vehicles, and

military information head quarters. The basic techniques of ad hoc network originated from

this field.

2. Commercial sector: Ad hoc network can be applied in emergency or rescue operations for

disaster relief efforts for example in fire, flood, or earthquake and so on. Emergency rescue

operations will go to places where communications are impermissible. Therefore proper

infrastructure and rapid deployment of a communication network is badly needed.

Information is relayed from one rescue team member to another over a small handheld

device. Other commercial application includes for instance ship to ship Ad Hoc Mobile

communication and so on.

3 Local level: Ad hoc networks can autonomously link immediate and temporary multimedia

network by using notebook or palmtop computers to distribute and allocate information

among conference or classroom participants. Besides, it can also be applied for home

networks where devices can be link. Another example includes taxicab, sports stadium, boat

and small aircraft.


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4 Personal Area Network (PAN): Short-range MANET can simplify the

intercommunication between a lot of mobile devices such as a PDA, a laptop, and a cellular

phone and there are a lot of new devices in this for MANETs. Wired cables can easily be

replaced with wireless connections.

Ad Hoc Network Performance Issues:

1.Distribution operation: due to the existence of MANET where there is no prerequisite for

the construction of the underlying network, so routing cannot rely on a particular node to

operate.

2 Loop-freedom: all the routing protocol should be consistent with the characteristics; we

must ensure the normal work in order to avoid waste of bandwidth.

3Demand-based operation: In order to reduce the burden on each node, if the link is not so

much the demand should be considered when using On-demand approach to the

establishment of the path, and only when the need for a particular path query, the

establishment of the path.

4 Proactive operation: with the On-demand concept of the contrary, if the network resources

fairly adequate, proactive table-driven approach could speed up the path to the establishment

of speed.

5 Security: Because it is the wireless environment, to how to ensure the security of the

connection cannot be ignored will be part of network security is also a MANET from theory

to implementation of the key challenges.


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REFRENCES

Integrating Wireless Technology by Williams Wheeler, Elsevier Digital Press. Wikipedia www.functionx.com Toh. C.K., 2002. Ad Hoc Mobile Wireless Networks Protocols and Systems. PrenticeHall,Inc

IETF MANET Working Group.http:// www.ietf.org/html.charters/manetcharter. html

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