Light tree

Light TreeLight Tree

Presented By:Presented By:

Jitendra YadavJitendra Yadav

11BCAA4611BCAA46

Index IntroductionIntroduction

History History

DefinitionDefinition

Need For TechnologyNeed For Technology

ApplicationApplication & & FunctionalityFunctionality

Requirement of TechnologyRequirement of Technology AdvantagesAdvantages and and DisadvantagesDisadvantages

Future enhancement Future enhancement

ConclusionConclusion

ReferencesReferences

TreeTree

IntroductionIntroduction

o The concept of light tree is introduced in a wavelength routed optical network which employs wavelength -division multiplexing (WDM).

o Point to multipoint

o Enables single-hop communication

o Increases the network throughput.

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HistoryHistory

o The concept was first published in 1978, and by 1980 WDM The concept was first published in 1978, and by 1980 WDM systems were being realized in the laboratory. The first systems were being realized in the laboratory. The first WDM systems combined only two signals. Modern systems WDM systems combined only two signals. Modern systems can handle up to 160 signals and can thus expand a basic can handle up to 160 signals and can thus expand a basic 10 10 Gbit/sGbit/s system over a single fiber pair to over 1.6 system over a single fiber pair to over 1.6 Tbit/sTbit/s..

o WDM systems are popular with WDM systems are popular with telecommunications companiestelecommunications companies because they allow them to because they allow them to expand the capacity of the network without laying more expand the capacity of the network without laying more fiber. By using WDM and fiber. By using WDM and optical amplifiersoptical amplifiers, they can , they can accommodate several generations of technology accommodate several generations of technology development in their optical infrastructure without having to development in their optical infrastructure without having to overhaul the backbone network. Capacity of a given link can overhaul the backbone network. Capacity of a given link can be expanded simply by upgrading the multiplexers and be expanded simply by upgrading the multiplexers and demultiplexers at each end.demultiplexers at each end.

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DefinitionDefinition

The concept of light tree is introduced in a wavelength routed optical network, which employs wavelength-division multiplexing(WDM).

Depending on the underlying physical networks

1) First Generation2) Second Generation3) Third Generation

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What is a Light Tree?What is a Light Tree?

A light tree is a point to point multipoint all optical channel, which may span multiple fiber links. Hence, a light tree enables single-hop communication between a source node and a set of destination nodes. Thus, a light tree based virtual topology can significantly reduce the hop distance, thereby increasing the network throughput.

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Light PathLight Path

A light path is an all-optical channel, which may be used to carry circuit switched traffic and it may span multiple fiber links. Assigning a particular wavelength to it sets these up.

A major objective of light path communication is to reduce the number of hops a packet has to traverse.

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Need Of Technology Need Of Technology

Data Security

Ease of installation

Eliminating Spark Hazards

High Bandwidth over Long Distances

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ApplicationsApplications

Teleconferencing

Videoconferencing

Internet NEWS distribution

Internet television etc..

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Teleconferencing Videoconferencing

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Internet NEWS distribution

Internet television

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Functionality Functionality

Unicast TrafficUnicast Traffic

Broadcast TrafficBroadcast Traffic

Multicast TrafficMulticast Traffic

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Unicast TrafficUnicast TrafficLight TreeLight Tree

Unicast TrafficUnicast TrafficLight TreeLight Tree

Unicast Traffic(contd.)Unicast Traffic(contd.)Light TreeLight Tree

Broadcast TrafficBroadcast TrafficLight TreeLight Tree

Multicast TrafficMulticast TrafficLight TreeLight Tree

Combining Unicast and Multicast Combining Unicast and Multicast TrafficTraffic

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Requirements

o Multicastcapable wavelength routing switches (MWRS) at every node in the network.

o More optical amplifiers in the network. This is because if we make n copies of an optical signal by using one or more optical splitters, the signal power of at least one copy will be less than or equal to 1/n times the original signal power; thus more amplifiers may be required to maintain the optical signal power above a certain threshold so that the signal can be detected at their receivers.

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ARCHITECTURE OF WAVELENGTH-ROUTED OPTICAL NETWORK

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MULTICAST SWITCH ARCHITECTURES

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Advantages Advantages

Data Security

Ease of installation

Eliminating Spark Hazards

High Bandwidth over Long Distances

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Disadvantages Disadvantages

Price

Fragility

Opaqueness

Requires special skills

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Future

o. In the future, as multicast applications become more popular and bandwidth intensive, there emerges a pressing need to provide multicasting support on WANs.

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ConclusionConclusionRecently, there has been a lot of interest in WDM based fiber optic networks. In fact, there is a general consensus that, in the near future, WANs will be based on WDM optical networks. So far, all architectures that have been proposed for WDM WANs have only considered the problem of providing unicast services. In addition to unicast services future WDM WANs need to provide multicast and broadcast services. A novel WDM WAN architecture based on light trees that is capable of supporting broadcasting and multicasting over a wide-area network by employing a minimum number of opto-electronic devices was discussed. Such WDMWAN can provide a very high bandwidth optical layer, which efficiently routes unicast, broadcast and multicast packet-switch traffic.

References

http://www.usdavis.edu

http://en.wikipedia.org/wiki/Traffic_Light_tree

http://www.slideshare.net/priyakrish792/light-tree-26890046

http://www.seminarsonly.com/IT/light%20tree.php

Thank YouThank You