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ABSTRACT: A new all-optical technique to convert on-off keying (OOK) signals into incoherently optical code division multiple access (OCDMA) signals is proposed and investigated. The technique is based on two stages of cross-gain modulation effect in semiconductor optical amplifiers. The output encoded signal presents an improved optical signal-to-noise ratio (OSNR) and may be generated at the same wavelength as the input signal. Simulation results indicate that OSNR and extinction ratio improvements higher than 20 and 8 dB are, respectively, achievable.
Transparent Optical Networks (ICTON), 2012 14th International Conference on, Coventry - England; 07/2012
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ABSTRACT: A new all-optical technique to label on-off keyed (OOK) payload signals is experimentally analysed. Such all-optical operation is accomplished by using a fibre optical parametric amplifier (FOPA) with the pump modulated by label information to amplify the OOK payload; as a result, the signal at the output of the FOPA becomes a ternary-amplitude optical packet (TAOP). It is shown that the technique may generate TAOPs with different power level distributions. Furthermore, the TAOP was propagated through a link on a field-trial network. The obtained eye-penalties are inferior to 0.7 dB and suggest that the optical packet could be properly propagated through metropolitan area networks.
Transparent Optical Networks (ICTON), 2011 13th International Conference on, Stockholm; 06/2011
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ABSTRACT: The performance of Optical Code/Wavelength Conversion (OCWC) switch architectures are investigated in this work. We employed hybrid technologies within in Optical Burst Switching (OBS) networks, which include wavelength and optical code division multiplexing. The simulated results demonstrate the concomitant increase of optical codes per wavelength and the utilization of Sparse Partial Optical Code/Wavelength Conversion. Both lead to a considerable decrease of the Burst Blocking Probability (BBP). In addition, such hybrid approach also improves the utilization of network resources. Index Terms— burst blocking probability, code/wavelength conversion architectures, optical burst switching (OBS), WDM/OCDM networks.
ICT 2011, Espanha; 05/2011
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ABSTRACT: In this work we analyze the performance and sensitivity to link failure of metropolitan networks based on the technology of optical packet/burst switching (OPS/OBS). We use ring and mesh topologies to evaluate through analytical modeling and computer simulations the impact of link failure on each topology. We adopt the parameters average number of hops and packet loss fraction to evaluate network performance. It is observed that mesh topologies with triple-connection node configuration (3×3) are more robust; consequently in case of link failure the impact of lost data is minimum compared with the other topologies and configurations considered.
Kaleidoscope: Beyond the Internet? - Innovations for Future Networks and Services, 2010 ITU-T; 01/2011
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Sarnoff Symposium, 2011 34th IEEE; 01/2011
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ABSTRACT: This work presents experimental results concerning a new all-optical technique that multiplexes two binary signals into a quaternary one. The technique is based on parametric amplification. Simulation and experimental results present a rather good agreement.
LAOP - OSA, São Paulo - Brasil; 09/2010
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ABSTRACT: Considering that optical packet/burst switching (OPS/OBS) are considered strong candidates for metropolitan networks in the near future, this work is a contribution evaluating the performance of some network models based on OPS/OBS mesh/ring architectures. We use both the conventional models of ring and mesh (Manhattan Street type), and slightly modified models implementing new structures, with cases of unidirectional and of bi-directional links. Our main goal here is to find through computer simulations the better architectures, in terms of (higher) capacity and (lower) latency. We choose the parameters average number of hops, total number of deflections and packet loss fraction as metrics for network performance. We observe that networks with best performance are the ones with largest number of different paths between nodes.
Telecommunications (AICT), 2010 Sixth Advanced International Conference on; 06/2010
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ABSTRACT: This paper proposes and investigates the performance of a dynamic routing and wavelength code assignment (RWCA) algorithm using hybrid technology with wavelength and optical code division multiplexing (WDM/OCDM) for Optical Burst Switching (OBS) network. An OCDM-based multigranularity optical cross-connect (MG-OXC) is used to enable the better granularity in optical path (wavelength and code) switching than the wavelength-based path. The results show that Random-Random heuristic has a better performance when the burst blocking probability as a function of traffic load is studied. In addition, show that WDM/OCDM technology increase the capacity and scalability in the optical network.
Sarnoff Symposium, 2010 IEEE; 05/2010
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ABSTRACT: The authors propose an original design based on multi-rate optical code paths (OCPs) for transport in advanced wavelength-division multiplexing/optical code division multiplexing (WDM/OCDM) networks. The authors utilise multi-length optical orthogonal codes (OOC) to obtain multi-rate OCPs. The performance of the proposed scheme is analysed and the impact of multiple access interference (MAI) and polarisation mode dispersion (PMD) over these OCPs is evaluated. Results show that not only multi-rate operation can be achieved but also MAI effects can be reduced, while mitigating PMD effects.
IET Communications 02/2010; · 0.83 Impact Factor
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ABSTRACT: In this work we investigate the effects of multiple access interference (MAI) and polarization mode dispersion (PMD) on two-dimensional wavelength-hopping time-spreading optical code paths. Analytical results show quantitative evaluation of the MAI and PMD effects and constraints at the outage probability. The contribution of each these sources of interference are used to help choose design of code parameters that increase performance of networks based on optical code paths (OCPs). By using a 2-D approach, flexibility and path availability is further increased in code/wavelength routed networks, without significant impact on resources.
Microwave and Optoelectronics Conference (IMOC), 2009 SBMO/IEEE MTT-S International; 12/2009
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ABSTRACT: The performance of Sparse Optical Code Conversion (SOCC) architectures is investigated in Optical Burst Switching (OBS) networks using a hybrid technology, which apply optical code and wavelength division multiplexing. The simulation results indicate that the increase of the number of optical codes and the utilization of SOCC conversion, lead to considerable decrease of the Burst Blocking Probability and latency. In addition, this hybrid technology also improves the utilization of network resources.
IMOC 2009, Brasil; 06/2009
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ABSTRACT: We propose a new all-optical labelling technique that uses parametric amplification to generate optical packets. This approach considers that an on-off keyed payload is inserted in a parametric amplifier, where the pump is modulated by label information. The parametric interaction between these signals induces power variations in the payload which, under certain conditions, becomes a ternary amplitude optical packet (TAOP). Computer simulations are used to test our proposal and to evaluate packet propagation. Our numerical results indicate that 11.25 Gb/s TAOPs can be successfully transmitted through metropolitan area network scale before a 1-dB penally is achieved.
Transparent Optical Networks, 2007. ICTON '07. 9th International Conference on; 08/2007
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ABSTRACT: This paper proposes a methodology to compare scheduling algorithms for congestion resolution in optical burst switching or optical packet switching networks, focusing on the issue of wavelength conversion capabilities. The performance of such algorithms when full wavelength conversion is available at the switching nodes are compared with the case of conversion capabilities over a limited range of wavelengths. The results presented show that limited range wavelength conversion is not necessarily performing worse than full wavelength conversion, as long as the correct terms of comparison are considered.
Global Telecommunications Conference, 2006. GLOBECOM '06. IEEE; 01/2007
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ABSTRACT: In this work we develop a performance evaluation for optical packet switching network (OPSN) architecture and optimized mesh topology with (OMT) comprising 2times2 optical bufferless nodes configuration. The analysis is carried out with analytic modeling and simulation methods using as basis for comparison the Manhattan Street topology with 16 nodes (MS-16). This work comes to validate our simulation methods, the search for optimized topologies, and the analytic modeling comes to clarify some important conceptual aspects of packet switched network operation. Besides the performance analysis, we have conducted an estimate of packet delay based on average number of hops, which contributes to QoS evaluation.
Telecommunications Symposium, 2006 International; 10/2006
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ABSTRACT: Recent work suggests that fiber four-wave mixing may be used to merge two wavelength multiplexed binary channels into a single quaternary signal. In this letter, we investigate the application of this technique to the optical packets generation considering that a 10-Gb/s payload is optically multiplexed to a 2.5-Gb/s label. Computer simulations are used to analyze the propagation of the generated quaternary optical packet in the dominance of amplified spontaneous emission noise. Results suggest that the optical packet may be propagated through metropolitan area networks length scales and that an average power around 0 dBm should be used to minimize the packet bit-error rate.
IEEE Photonics Technology Letters 02/2006; · 2.19 Impact Factor
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ABSTRACT: It is experimentally demonstrated that fibre four-wave mixing may be used to optically multiplex two binary signals into a single quaternary one. The behaviour of this quaternary signal is investigated as a function of the extinction ratios of the input binary signals and a very good agreement is found with theoretical predictions
Electronics Letters 02/2006; · 0.96 Impact Factor
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ABSTRACT: In this work, we investigated the impact of polarization-mode dispersion (PMD) in optical networks using the hybrid technology of wavelength-division multiplexing and optical code-division multiplexing. In these networks, virtual paths based on code/wavelength channels (VCP/VWP) are dynamically established to attend the traffic demand. We use a routing channel assignment based on genetic algorithm to establish the VCP/VWPs. The main results show that the network blocking probability caused by PMD depends on parameters of optical orthogonal codes like weight and length.
IEEE Photonics Technology Letters 01/2006; · 2.19 Impact Factor
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ABSTRACT: This paper analyses the effects of polarization mode dispersion (PMD) on the blocking probability performance of optical networks that uses the hybrid technology of wavelength division multiplexing and optical code division multiplexing (WDM/OCDM). In these networks virtual paths based on code/wavelength channels (VCP/VWP) are dynamically established to attend the traffic demand. We use a routing channel assignment (RCA) based on genetic algorithm to established the VCP/VWP's. The main results show that the network blocking probability caused by PMD depends on parameters of optical orthogonal codes (OOC) like weight and length.
Microwave and Optoelectronics, 2005 SBMO/IEEE MTT-S International Conference on; 08/2005
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ABSTRACT: In this work, optical networks using the hybrid technology of wavelength division multiplexing and optical code division multiplexing (WDM/OCDM) with all-optical code converters are investigated. Expressions to show the code converter node performance including the effects of polarization mode dispersion (PMD) are derived. The main results show that the effects of PMD can decrease the code converter performance. It is also investigated a simple analytical formalism to solve the problem of optimal code converter placement. This formalism shows the network performance when the code converter are optimally/uniformly distributed in the network.
Microwave and Optoelectronics, 2005 SBMO/IEEE MTT-S International Conference on; 08/2005
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ABSTRACT: This paper analysis the use of hybrid technology of wavelength division multiplexing and optical code division multiplexing (WDM/OCDM) for optical burst switching (OBS) with two-way reservation scheme. The architecture of WDM/OCDM edge router that utilizes fast circuit switching by dynamically assigning and releasing virtual optical code/wavelength path channels (VOCP/VWP) over bufferless optical core is described. We derived expressions for burst blocking probability for the edge router and analyzed the behavior of the network in function the traffic load and latency. The main results show that are decreasing the burst blocking probability and network latency when increase the number of codes per wavelength.
Microwave and Optoelectronics, 2005 SBMO/IEEE MTT-S International Conference on; 08/2005
