Mobile ADHOC Networking

7/29/2019 Mobile ADHOC Networking

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Mobile Ad Hoc Networking,MESH Networking, Wi-MAX


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MANETs

Capable of extending network service toareas without existing infrastructure

High expectations of future capabilities

Large volume of existing research Expected to be a key element of 4G

wireless network architecture

MANET capabilities are expected to bean overall driving force for next-generation wireless functionalities


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MANET Extending theInfrastructure


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Key Elements of MANETs

Formed dynamically through thecooperation of independent nodes

Nodes do not have any pre-specified roles

Nodes make decision independently basedon the current network situation

Nodes are expected to behave as routers

As routers, nodes must assist in discoveryand maintenance of network routes


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Formation of a MANET

Mobile Ad Network HOME

A

B

C


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MANET Design complexities &Constraints

Infrastructureless with distributed management

Frequent and unpredictable topology changes

Physical layer limitation

Limited link bandwidth and quality

Variation in node capabilities

Energy Considerations

Network reliability

Network security

Network scalability Quality of service


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MANET Management

Multihop network each device must carry burden of routing packetsfrom source to destination

Each Node handles part of the management of the network

Fault detection is extremely difficult because of the distributed design


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MANAET Distributed Management


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MANET Topology

Topology changes occur with every move of a mobile

node Every topology change results in route changes

Route changes lead to network partitions and in mostinstances some packet losses

A

B

C


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MANET Physical Layer

Limited wireless range and sharedfrequency space leads to specificmobile ad hoc problems

High risk of collisions and packet losses

Hidden terminal problems

Exposed terminal problem


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Collision Risk and Packet Loss

Node A and Node B simultaneously try to communicate with NodeC. Their traffic collides and both packets are lost at Node C.

A

C

B


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Hidden Terminal


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Exposed Terminal


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MANET Congestion Control

Adapted Ready-to-Send (RTS)/Clear-to-Send (CTS) protocols arethe current resolutions to MANET congestion control, hidden

terminal and exposed terminal problems.


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MANET Bandwidth Constraints

Bandwidth used by MANETs has a widerange of capacity levels.

Wireless bandwidth in general is more

error-prone than wired links. Wireless bandwidth in general is more

insecure than wired links.

These factors lead to lower capacity

throughput than equivalent wired links. The lower capacity wireless links lead to

higher congestion problems.


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MANET Node Variability

Nodes may have one or more radiointerfaces of varying transmissioncapabilities

Node radios may operate in differentfrequency bands

Node radio capabilities may result inasymmetric links

Node hardware and software configurationscan affect processing capabilities


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MANET Node Variability


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MANET Energy Constraints

Link Distance Controlled through topology management

Goal is to reduce overall network powerconsumption as much as possible throughassignment of per node transmit power levels

Routing Protocols Minimizing routing paths reduces power needed

to send a packet end-to-end

Transmit power levels can greatly affect theability of the network to control congestion Hidden terminal problems arise


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MANET Power Considerations


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MANET Reliability

Reliability occurs by routing and forwardingpackets

Network overload

Misbehaving nodes Broken links

No centralized management makes theseproblems difficult to detect and isolate

Reliability thus must rely on properlydesigned protocols


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MANET Security

Mobile networks are physically insecure

Distributed management means overallsecurity is dependent on individual node

security MANET security considerations

Confidentiality prevent eavesdropping

Access control protecting the wireless

infrastructure

Data integrity preventing tampering of traffic

Denial of service


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Wireless Eavesdropping

Wireless eavesdropping can be performed byanyone who has a radio receiver that is compatiblewith the signaling used by the Ad Hoc network

A

C

B


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MANET Scalability

Scalability is critical to the successfuldeployment of a MANET

Factors affecting MANET scalability

Addressing

Routing

Location management

Configuration management

Interoperability

Security

High-capacity wireless technologies


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MANET Service Quality

Quality of Service is of keyimportance to all a networks

MANETs makes the task ofmaintaining QoS more difficult


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MANET Applications Tactical Networks Military communications and operations control in battlefield environments. Sensor Networks Collection of embedded sensor devices used to collect real-time data to automate

everyday functions. Weather monitoring Earth activities Manufacturing Equipment automation

Emergency Services Search-and rescue operations as well as disaster recovery and medical needs. Patient records retrieval at point of contact Loss of infrastructure due to catastrophic disaster

Commercial Environments electronic commerce Make and receive payments from anywhere Access customer records from the field Vehicular access of road conditions, weather, or local news

Home and Enterprise Networking - Anywhere access for PDA Personal area networks

Educational Applications virtual classrooms or conference rooms for use during conferences, meetingsor lectures.

Entertainment

Multiuser games, robotic pets, and outdoor Internet access. Location-aware Services Follow-on services Call forwarding anywhere Transmission of actual workspace to current location Advertise location specific services Location specific travel guides Service availability information


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Mobile Ad Hoc Networks

Ad hoc wireless networks eliminate theconstraints of infrastructure and enabledevices to create and join networks onthe fly

any time, anywhere

for

virtually any application.


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MANETs and MESH Networks

Combining two point-to-point or point-to-multipointMANETs begins the basic design of a MESH network.

MESH networks are semi-mobile. The network nodesmay change but the overall coverage is somewhat

constant. MESH networks have dedicated routing nodes where

every node in an MANET is a routing node.

MANETs slowly develop into MESH networks as thenumber of nodes increases.

MESH nodes normally are connected to every othernode within range creating a mesh of coverage paths.


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MESH Network Characteristics

Robust network routing

Routing addresses congestion concerns

Routing addresses line of sight concerns

Node density increases network throughput

Purely dynamic mesh is not suitable for large scaledeployment at this time.

Development of protocols for the dynamic natureare still needed

Development of protocols for address assignment

in a mobile environment are still needed. MESH networks are usually designed to cover large

geographic regions than MANETs.


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MESH Network Example

A

B


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Route Discovery

(a) Range of A's broadcast.

(b) After B and D have received A's broadcast. (c) After C, F, and G have received A's broadcast.

(d) After E, H, and I have received A's broadcast.

Shaded nodes are new recipients. Arrows show possible reverse routes.


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Route Discovery (2)

Format of a ROUTE REQUEST packet.

When a route request arrive (B and D)

Source address and ID is looked up : noduplicate

If route is known then Route Reply, else nextstep

Increment hop count and rebroadcast the RouteRequest


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Route Discovery (3)

Format of a ROUTE REPLY packet.


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Route Maintenance

(a) D's routing table before G goes down.(b) The graph after G has gone down.

Use periodic Hello

B 3

F 3

F


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MANET and MESH Differences

Logical MANET Network Logical MESH Network


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Large Scale MESH Networks

Large Scale deployments are possiblewith the proper design in place toprovide routing nodes connected to

wireline networks.

Current large scale projects includeresearch into Providing Metropolitan

Area Network service across a MESHtopology.


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WiMAX

Worldwide Interoperability forMicrowave Access

Telecommunications technologyproviding wireless data over longdistances in a variety of ways

FROM Point-to-Point links TO full mobile

cellular type access


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Current devices

The list is growing every day!


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Advantages

Carrier Class, High-Speed, WirelessBroadband

Lower cost that cellular

Greater range than WiFi, Up to 3000square miles!


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Frequency

Non line of site uses 2 Ghz to 11 Ghz.(Similar to WiFi)

Line of site as high as 66 Ghz.


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WiMAX Forum

WiMAX was created byWiMAX Forum in June2001.

Industry-led, not-for-profit corporation

Dedicated to certifying the

interoperability of WiMAXProducts
http://images.google.com/imgres?imgurl=http://www.neraworld.com/upload/Image%2520Folders/General%2520Illustrations/wimax_forum_color_logo.jpg&imgrefurl=http://www.neraworld.com/en/Products_and_Solutions/Product_families/&h=349&w=328&sz=26&hl=en&start=11&tbnid=jB9GUnMiV7_t0M:&tbnh=120&tbnw=113&prev=/images%3Fq%3Dwimax%26gbv%3D2%26svnum%3D10%26hl%3Den%26safe%3Doff%26sa%3DGhttp://images.google.com/imgres?imgurl=http://www.neraworld.com/upload/Image%2520Folders/General%2520Illustrations/wimax_forum_color_logo.jpg&imgrefurl=http://www.neraworld.com/en/Products_and_Solutions/Product_families/&h=349&w=328&sz=26&hl=en&start=11&tbnid=jB9GUnMiV7_t0M:&tbnh=120&tbnw=113&prev=/images%3Fq%3Dwimax%26gbv%3D2%26svnum%3D10%26hl%3Den%26safe%3Doff%26sa%3DG


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WiMAX Forum Certified

Products and marketing materialspass conformance and interoperabilitytesting

Display certification


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Forum WiMAX Description

A standards-based technology enabling

the delivery of last mile wireless

broadband access as an alternative to

cable and DSL.

www.wimaxforum.org


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WiMAX versus WiFi

Long range systemcovering kilometers

Similar to Cell

phone Quality Service

mechanismbetween Base

Station and userdevice

Highly scaleabe

Shorter range systemcovering hundreds ofmeters

Similar to CordlessPhone

Quality Servicemechanism similar to

fixed Ethernet


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Different Providers

Cellular Operators

Wireline Carriers

Cable Operators

MSO-multiple system operators


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Main WiMAX Competitors

Nortel

Intel

Sprint Nextel


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WirelessMAN

WirelessMAN is based on IEEE 802.16standard.

WiMAX allows user to browse internetfrom laptop computer without walljack.


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IEEE Standards

Fixed WiMAX-systems built using802.16e-2004(802.16d) air interfacetechnology

Mobile WiMAX systems built using802.16e-2005 air interfacetechnology


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References

http://wi-fitechnology.com/papers+req-showcontent-ie-7-page-2.html

http://www.sigcomm.org/sigcomm2006/?tutori

als http://www.commsdesign.com/showArticle.jht

ml;jsessionid=2FYCYRNWG2MY0QSNDLRCKH0CJUNN2JVN?articleID=160911814

Basagni, Stefani, Conti, Marco, Giordano, Silva,Stojmenovic, Ivan (2004). Mobile Ad HocNetworking. Wiley & Sons, Inc, New Your.


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References Cont

www://intel.com

www://nortel.com

www://youtube.com

www.apertonet.com http://www.wimaxforum.org/home/
http://www.apertonet.com/http://www.apertonet.com/

Mobile ADHOC Networking

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