Manoj Kumar Dutta

Design and Performance Analysis of Deflection Routing Based Intelligent Optical Burst Switched (OBS) Network

Optical burst switching (OBS) is a promising switching technology for realization of terabit optical network. However, the lack of optical processing capability results in increased blocking probability and limits the network performance. Efficient contention resolution is therefore necessary. Optical burst-switched networks are usually implemented using efficient contention resolution protocols like deflection routing, however deflection routing approach resolves the congestion by exploiting alternate available paths and utilizes the resources effectively. If contention is resolved by traditional deflection routing then there is no guarantee that the control packet will be able to reserve all the wavelengths successfully up to the destination on the alternate path, especially in a high traffic load situation. The present paper proposes a scheme of deflection routing by assigning suitable wavelengths to various routed paths based on respective traffic to be routed. A mathematical model for the same has been developed and the network performance has been simulated using MATLAB to establish congestion performance of the proposed scheme.

Stimulated Raman Scattering Induced Power Penalty Analysis for Optical WDM Network

In optical wavelength-division multiplexing (WDM) systems, if the number of users is increased; the crosstalk becomes more severe due to imperfections in the passive optical filters (gratings) and nonlinear effects due to the power increasing in the optical fiber. In this research paper we have considered Stimulated Raman Scattering (SRS) as the source of nonlinear degradation in the multichannel system. The power penalty induced by Raman crosstalk has been evaluated for both wavelength division multiplexed and dense wavelength division multiplexed networks. It is observed that the penalty is higher at higher input power, higher number of channels and higher bit rates used for transmission

Modeling and performance analysis of optical packet switching network using fiber delay lines

One of the key problems in application of packet switching in optical domain is the handling of packet contentions that take place when two or more incoming packets are directed to the same output line. This problem can be solved by incorporating fiber delay lines (FDLs) in the switch architecture. In the present paper simulated behavior of an optical node has been realized by using an n × m optical switch and recirculating optical delay lines, A mathematical model for the proposed switch architecture is developed employing packet queuing control to estimate the blocking probability for the incoming traffic. This investigation infers the scaling behaviors of the proposed architecture to maintain efficient use of the buffer under Poisson traffic loading.

Design and Simulation of Intelligent Optical WDM Switching Node Based on Erlang Traffic Model

In this paper we propose a new architectural switching nodes consisting of two processing nodes that follow Erlang B and Erlang C traffic respectively. The developed model is used to best utilize the given number of output channels to achieve the least blocking probability. An appropriate mathematical model has been further devised and its call blocking probability has been enunciated. Performance of the model has been evaluated for different values of blocking probabilities. It has been observed that the performance of the network is satisfying for different design parameters.

Design and Performance Analysis of Noise Equivalent Model for Optical Fiber Link

In optical communication system different types of noises may be introduced into the signal. The effect of noise and corresponding degradation in the signal quality is of great interest for the design of fiber-optic communication systems. In the present paper an electrical equivalent form of different important noises has been developed in order to investigate its effects on the efficiency of an optical fiber link. The basic components of an optical link are laser diodes, fiber, splices, and optical detector. In the proposed model the laser diode is represented as voltage source with internal resistance. Thermal noise in fiber, connectors, and splices is estimated by using an equivalent resistor. PIN photodetector is choosen for the proposed optical link and equivalent circuit model for the same is derived by carrier rate equations using RC circuit with current sources. The variation of noise current with the variation of frequency is shown.

Comparative Performance Analysis of Different Segmentation Dropping Schemes Under JET Based Optical Burst Switching (OBS) Paradigm

Optical burst switching (OBS) is the most promising technique to explore the huge bandwidth offered by the optical fiber. In OBS network sender does not wait for an acknowledgment of path reservation and uses only one-way reservation for data transmission. In spite of being very promising this one-way reservation policy of OBS technology may create contention during data transmission. Contention in the network leads to loss of packets as a result the efficiency of the optical network deteriorates. To achieve optimum performance of an OBS network it is essential to employ proper contention resolution techniques. This article investigates the contention resolution capability of segmentation based dropping scheme for JET based OBS network. Performances of three different segmentation burst dropping policies such as head dropping; tail dropping and modified tail dropping are discussed and compared for above mentioned networks. Both finite and infinite input cases are considered here.

Study and Comparison of Erbium Doped Fiber Amplifier (EDFA) and Distributed Raman Amplifier (RA) for Optical WDM Networks

This article investigates the comparative performance analysis between EDFA and RA that are usable for high performing WDM transmission systems. Performances are compared by analyzing eye diagrams and gain flatness using standard simulation tools.

Design and performance analysis of optical WDM ring network using proxy node strategy

In this paper an analytical model of an optical ring network which is capable of handling WDM traffic intelligently has been presented. The proposed architecture can be used to ease the traffic congestion in a ring network. The backbone of the proposed model is the use of a proxy node which is connected to a particular number of nodes, depending upon the traffic, then diverting their traffic and thereby increasing throughput. A probabilistic model for the proposed network architecture is developed employing packet queuing control to estimate the average waiting time of packets in the buffer and the average number of packets in the buffer for different incoming traffic arrival rate.