Ad HocNetworks

8/12/2019 Ad HocNetworks

http://slidepdf.com/reader/full/ad-hocnetworks 1/26

AD-HOC NETWORKSDavid Durich and Daniel Montesinos

Telecommunication systems & networks



Index

Introduction

What is Ad-hoc?

History and Evolution

Basic features and principles

Security

Types Wireless MESH networks

MANET

Applications

Advantages/Disadvantages

How to create an Ad hoc Network

Windows

Linux

Conclusion

Bibliography

Questions



Introduction – What is Ad-hoc?

A decentralized type of wireless network.

It does not depend on a preexisting infrastructure.

Each node participates in routing by forwarding data

for other nodes The determination of which nodes forward data is

made dynamically based on the network connectivity.

Ad hoc networks can use flooding for forwarding the

data. (distributing algorithm)




Network configured with router and Acces point




Ad-hoc network



Introduction - History and Evolution

70’s:

U.S. started a research project to interconnect thetactical units deployed in areas of military conflictwithout requiring the presence of a fixed network.

The project, called PRNET (Packet Radio NETwork), useda combination of ALOHA and CSMA protocols,combined with a Distance Vector Algorithm.

80’s:

Evolved into SURAN (Survivable Adaptive RadioNetwork), uses hierarchical routing protocol Link StateAlgorithm.



Introduction - History and Evolution

90’s:

IETF created MANET working group, looking for

standardizing the relevant aspects of ad hoc networks

to use in commercial applications. 00’s:

Was created the Ad Hoc Network Consortium in Japan,

aiming to unite the interests and efforts of industry.

10’s:

Nowadays, it is using in many projects, especially where

we can not have a fixed infrastructure.



Basic features and principle

Dynamic topology

Variability of the radio channel

Do not require network infrastructure Using multi-hop communications

Limited bandwidth



Security

Security is cause for concerning in and ad-hocnetwork.

How can an user be sure that nobody is snooping on thetraffic forwarded by a node?

Is the receiver user the person who claims to be?

The requirements for authentication, confidentialityor integrity are the same as for many other public

communications networks Cryptography: We can’t trust with communication

means



Types

For its implementation can be classified as:

Wireless MESH networks

Mobile network: MANET

Hybrid MESH networks



Types – Wireless MESH networks

It is a communications network made up with static mesh

routers, which have ad-hoc characteristics.

Mesh clients:

Laptops, cell phones Routers

Other wireless devices

It can be implemented with various wireless

technologies including 802.11, 802.15, 802.16, cellular

technologies or combination of more than one type

More than 70 routing algorithms



Types – Wireless MESH networks

It is a communications network made up with static mesh

routers, which have ad-hoc characteristics.

Mesh clients:

Laptops, cell phones Routers

Other wireless devices

It can be implemented with various wireless

technologies including 802.11, 802.15, 802.16, cellular

technologies or combination of more than one type

More than 70 routing algorithms



Types - MANET

It’s a self-configuring infra structurless network ofmobile devices connected by wireless links

Each device is free to move independently in any

direction, so it will change its links connection toother devices frequently

Each node must forward traffic unrelated to its ownuse, such as router

Types Vehicular Ad Hoc Networks (VANETs)

Intelligent Vehicular Ad hoc Networks (InVANETs)

Internet Based Mobile Ad hoc Networks (iMANET)



Types - MANET

It’s a self-configuring infra structurless network ofmobile devices connected by wireless links

Each device is free to move independently in any

direction, so it will change its links connection toother devices frequently

Each node must forward traffic unrelated to its ownuse, such as router

Types Vehicular Ad Hoc Networks (VANETs)

Intelligent Vehicular Ad hoc Networks (InVANETs)

Internet Based Mobile Ad hoc Networks (iMANET)



Applications

Military: decentralized network configuration is an

operational advantage, or even a necessity.

Rescue operations in remote areas

When local coverage must be installed quickly in aconstruction site.

Public wireless access in urban areas.

Environmental monitoring: used to predict waterpollution or to provide early a natural catastrophe

warning.



Applications

Domestic

Share information among participants of a conference

Home networking applications, where devices can

communicate directly to exchange information (video,audio, alarms, etc)

Autonomous network of interconnected domestic robots

that clean, do security surveillance, and other similar

tasks.



Advantages/Disadvantages

Advantages

Independence from central network administration

Self-configuring, nodes are also routers

Self-healing through continuous re-configuration

Scalable: accommodates the addition of more nodes Flexible: similar to being able to access the Internet from many

different locations

Disadvantages

Each node must have full performance

Throughput is affected by system loading Reliability requires a sufficient number of available nodes.

Sparse networks can have problems

Large networks can have excessive latency (high delay), whichaffects some applications



How to create an Ad hoc Network -

Windows

1. Click on Start

(Windows icon) and

type wireless. Click on

Manage wirelessnetworks.




Windows

2. Click on Add to add a network.

http://www.kombitz.com/wp-content/uploads/2009/02/adhoc-2.jpg





Windows

3. Click on Create an ad hoc network.







Windows

4. Click on Next.




Windows

5. Enter a name for your network and configure

the security options. Click on Next when you are

done.






Linux

1. Switch the card into ad hoc mode

2. Set the channel/frequency that you want to use

3. Add the name (ssid) for the network you want to create/join

4. Add a WEP encryption key 5. Make up the IP address



Conclusion

Mobile ad hoc networks present a new scenario for aneasy connectivity of users in a network withoutdepending on pre-existing or pre-establishedconditions, either from a logical perspective and

infrastructure. Also, with ad hoc is used less LAN accesspoints and potentially less transmission power.

However, Ad hoc networks should overcome manytechnological and technical constraints to be considered

for general use and, is still far from providing ascenario of connectivity and total mobility between allautonomous devices.



Bibliography and refereneces

Wikipedia

Z. J. Haas et al., Guest Editorial, IEEE JSAC. “Special Issue onWireless Networks”. Vol. 17, No. 8, Aug. 1999, pp. 1329 – 32.

M.S. Corson, J. P. Macker, and G. H. Cirincione. “Internet – BasedMobile Ad Hoc Networking”. IEEE Internet Computing, July – August

1999. R. Ramanathan and J. Redi. “A Brief Overview of Ad Hoc Networks:

Challenges and Directions”. IEEE Communications Magazine – 50thAnniversary Commemorative Issue/May 2002.

Novel Algorithms and Techniques in Telecommunications, Automation

and Industrial Electronics by Tarek Sobh, Khaled Elleithy, AusifMahmood and Mohammad A. Karim (Oct 21, 2008).

Departamento d’Arquitectura de Computadors, UniversitatPolitècnica de Catalunya (UPC).



Documents

Ad HocNetworks