Performance issues in optical burst/packet switching

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-01524-3_8This chapter summarises the activities on optical packet switching (OPS) and optical burst switching (OBS) carried out by the COST 291 partners in the last 4 years. It consists of an introduction, five sections with contributions on five different specific topics, and a final section dedicated to the conclusions. Each section contains an introductive state-of-the-art description of the specific topic and at least one contribution on that topic. The conclusions give some points on the current situation of the OPS/OBS paradigms

AWG-based optical switches performance using crosstalk limiting schedulers

According to a generalized opinion of the scientific community, Arrayed Waveguide Gratings (AWG) are one of the most promising passive optical devices for terabit optical switching systems. These devices permit to build high-performance all-optical WDM switches thanks to their wavelength routing capabilities, in addition to their high information density and lower power consumption. In previous works, we showed that wavelength reuse across different ports introduces in-band crosstalk which strongly limits scalability of AWG-based backplanes. We also proved that this limitation can be overcome by modified scheduling algorithms that reduce the probability of reusing the same wavelength in different ports of the AWG device, significantly reducing or even avoiding the effect of in-band crosstalk. In this paper, we extend several previously proposed scheduling algorithms to enhance their performance. The new algorithms permits to build AWG-based switches of larger sizes while maintaining small bit error rates (BER)

Guaranteeing packet order in IBWR optical packet switches with parallel iterative schedulers

The input-buffered wavelength-routed (IBWR) switch is a scalable switch fabric for optical packet switching (OPS) networks. In synchronous operation, when optical packets are of a fixed duration and aligned at switch inputs, the scheduling of this architecture can be characterised by a type of bipartite graph matching problem. This challenges the design of feasible algorithms in terms of implementation complexity and response time. A previous work presented and evaluated the insistent parallel desynchronized block matching (I-PDBM) algorithm for the IBWR switch. I-PDBM is a parallel iterative scheduler with a good performance and a simple hardware implementation. However, the algorithm does not maintain the packet sequence. In this paper, we present the I-PDBM algorithm with packet ordering (OI-PDBM), which prevents mis-sequencing and behaves as I-PDBM in terms of delay, buffer requirements and convergence speed

Photonics in switching: Architectures, systems and enabling technologies

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