Placement of Wavelength Converters in Dynamically Routed All Optical Networks in presence of Tunable Transceivers

Efficient routing with optimal resources is one of the challenging tasks in the design of DWDM networks. Wavelength Converter (WC) is an important resource, as the placement of WCs affects the network performance and the quantity of WCs affects the cost of the network. With the help of WCs the network performance can be maximized by removing the wavelength continuity constraint. As WCs are very expensive, selecting the candidate nodes for the placement of WCs in a network is important. In this paper we have proposed an optimized approach for the placement of WCs in the presence of tunable transceivers (TTRs) and fixed transceivers (FTRs). The performance analysis has been carried out for above approaches. Observation shows that sparse partial wavelength converters with various loads requires only 2.4% converters. When tunable transceivers are used an average reduction of 73% in blocking probability and average saving of 91% in required number of converters.

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Wavelength Converter Based Optimized RWA for All Optical Networks

Asian Journal of Computer Science and Technology ◽

10.51983/ajcst-2019.8.2.2131 ◽

2019 ◽

Vol 8 (2) ◽

pp. 111-115

Author(s):

Shilpa S. Patil ◽

Bharat S. Chaudhari

Keyword(s):

Optical Networks ◽

Network Performance ◽

Blocking Probability ◽

Wavelength Assignment ◽

Wdm Networks ◽

Optimal Placement ◽

Wavelength Converters ◽

Wavelength Converter ◽

Call Blocking ◽

Call Blocking Probability

Wavelength converters are used in WDM networks to avoid call blocking and minimizing the blocking probability. Optimal placement of wavelength converters restricts the call blocking probability, the complexity and improves the overall network performance of the network. In this paper, we propose a new weight dependent routing and wavelength assignment algorithm for the optimal placement of the wavelength converters. The wavelength converter placement was considered separately at all the nodes and the partial nodes. Our algorithm outperforms the previously reported studies and requires a lesser number of wavelength converters to achieve the required performance. It reduces the blocking probabilities up to 5.4% and shows that the first four nodes primarily control the blocking performance of the network. The study also reveals that instead of merely increasing the number of converters, their placement at the right location plays a crucial role in improving the performance. Initially, although an increase in the number of the wavelengths also improves the network performance, the further increase does not contribute much to the reduction of the blocking probability.

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Design of all Optical Packet Switching Networks

Sultan Qaboos University Journal for Science [SQUJS] ◽

10.24200/squjs.vol7iss1pp1-10 ◽

2002 ◽

Vol 7 (1) ◽

pp. 1

Author(s):

Hussein T. Mouftah

Keyword(s):

Optical Networks ◽

Large Scale ◽

Optical Network ◽

Optical Switches ◽

Traffic Load ◽

Wavelength Converters ◽

Small Scale ◽

Wavelength Converter ◽

All Optical ◽

The Impact

Optical switches and wavelength converters are recognized as two of the most important DWDM system components in future all-optical networks. Optical switches perform the key functions of flexible routing, reconfigurable optical cross-connect (OXC), network protection and restoration, etc. in optical networks. Wavelength Converters are used to shift one incoming wavelength to another outgoing wavelength when this needs to be done. Always residing in optical switches, they can effectively alleviate the blocking probability and help solve contention happening at the output port of switches. The deployment of wavelength converters within optical switches provides robust routing, switching and network management in optical layer, which is critical to the emerging all-optical Internet. However, the high cost of wavelength converters at current stage of manufacturing technology has to be taken into consideration when we design node architectures for an optical network. Our research explores the efficiency of wavelength converters in a long-haul optical network at different degrees of traffic load by running a simulation. Then, we propose a new cost-effective way to optimally design wavelength-convertible switch so as to achieve higher network performance while still keeping the total network cost down. Meanwhile, the routing and wavelength assignment (RWA) algorithm used in the research is designed to be a generic one for both large-scale and small-scale traffic. Removing the constraint on the traffic load makes the RWA more adaptive and robust. When this new RWA works in conjunction with a newly introduced concept of wavelength-convertible switches, we shall explore the impact of large-scale traffic on the role of wavelength converter so as to determine the method towards optimal use of wavelength convertible switches for all-optical networks.

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