R. Van Caenegem

IST-LASAGNE: towards all-optical label swapping employing optical logic gates and optical flip-flops

The Information Society Technologies-all-optical LAbel SwApping employing optical logic Gates in NEtwork nodes (IST-LASAGNE) project aims at designing and implementing the first, modular, scalable, and truly all-optical photonic router capable of operating at 40 Gb/s. The results of the first project year are presented in this paper, with emphasis on the implementation of network node functionalities employing optical logic gates and optical flip-flops, as well as the definition of the network architecture and migration scenarios.

From IP over WDM to all-optical packet switching: economical view

In this paper, a technoeconomical study of several (optical) packet-switching node architectures is described. Therefore, different architectures proposed in IST-WASPNET and IST-LASAGNE projects as well as a standard optical circuit switching approach are considered, and their economical impact is estimated by means of cost comparisons between the different technologies. The switching architectures all use optical fiber as a transport medium, but each of them uses a different technology to process switching. Their cost is evaluated as a function of most characteristic parameters for each technology. In the all-optical approaches, the main cost is that related to the fiber assembly, whereas for electronic processing, the most expensive cost is related to the optical-electronic-optical (OEO) conversions. The results show that the integration of optical components is crucial to make all-optical packet-switching nodes feasible.

Benchmarking and viability assessment of optical packet switching for metro networks

Optical packet switching (OPS) has been proposed as a strong candidate for future metro networks. This paper assesses the viability of an OPS-based ring architecture as proposed within the research project DAVID (Data And Voice Integration on DWDM), funded by the European Commission through the Information Society Technologies (IST) framework. Its feasibility is discussed from a physical-layer point of view, and its limitations in size are explored. Through dimensioning studies, we show that the proposed OPS architecture is competitive with respect to alternative metropolitan area network (MAN) approaches, including synchronous digital hierarchy, resilient packet rings (RPR), and star-based Ethernet. Finally, the proposed OPS architectures are discussed from a logical performance point of view, and a high-quality scheduling algorithm to control the packet-switching operations in the rings is explained.

On the Laws and Customs of England. Essays in Honor of Samuel E. Thorne

Investigating a wide range of problems in the development of English law, this collection of original essays honors the contributions of Samuel D. Thorne to the study of English legal history from the eleventh to the seventeenth century. The essays combine close study of legal texts and doctrines in their own setting with broader analysis of the interaction of legal and social change. Although each essay has its own historiographical context, a substantial unity is achieved.Originally published in 1981.A UNC Press Enduring Edition -- UNC Press Enduring Editions use the latest in digital technology to make available again books from our distinguished backlist that were previously out of print. These editions are published unaltered from the original, and are presented in affordable paperback formats, bringing readers both historical and cultural value.

The Design of an Allo-Optical Packet Switching Network

Recent advances in the all-optical signal processing domain report high-speed and nontrivial functionality directly implemented in the optical layer. These developments mean that the all- optical processing of packet headers has a future. In this article we address various important control plane issues that must be resolved when designing networks based on all-optical packet-switched nodes.

Contention Resolution for Burst-Mode Traffic Using Integrated SOA-MZI Gate Arrays and Self-Resetting Optical Flip-Flops

We demonstrate a photonic routing system that resolves the contention between bursty optical packets. The circuit is realized exclusively with integrated photonic components through the interconnection of semiconductor optical amplifier Mach-Zehnder interferometers gate arrays and optical flip-flops. The system resolves the contention - without burst segmentation - in the wavelength domain with a low power penalty ( < 1 dB).

Successful interconnection of SOA-MZI arrays and flip-flops to realize intelligent, all-optical routing

We demonstrate an intelligent routing system through the interconnection of 8 optical gates. Contention resolution of bursty packets using integrated MZIs and flip-flops is reported with <1dB power penalty.

All-optical label swapping: a challenge for node dimensioning

All optical label swapping (AOLS) is a promising packet switching technology as it intends to solve the potential mismatch between fibre capacity and router packet forwarding capacity. In this paper we investigate how the use of all-optical label swapping in an optical packet switching network creates some challenges from the node dimensioning point of view. To lower the cost of the AOLS-node, it is beneficial to reduce the number of different labels used throughout the network and hence the number of bits occupied by the label. To this purpose label stripping, a label switching strategy based on stripping of local labels is proposed. In this paper we compare label stripping to label swapping from the point of node dimensioning and we will map the impact of other network parameters on the AOLS node dimensions.

Scalable Designs for All-Optical Packet-Switching Nodes

New services and high bandwidth demanding applications will dramatically change the operators requirements with respect to future network architectures and topologies. The advent of bandwidth-intensive video applications will stimulate the design of high throughput and flexible network architectures. In this network evolution All-optical Label Swapping (AOLS) can play a key role. AOLS is a key functional type of optical burst/packet switching that intends to solve the potential mismatch between fibre capacity and routing burst forwarding capacity. This paper discusses how the original AOLS-node can be adapted to be more scalable. The new node designs are based on wavelength striping and the use of one control wavelength which transports only the labels. Then, for the remaining data wavelengths (transport of payloads), AOLS-blocks with limited intelligence can be installed.

Historical Reflections on Islam and the Occident

The media and political scientists create the impression that the world of Islam and the Occident are two totally different civilizations. The author shows, on the contrary, that life in the 14 centuries of the Christian Middle Ages and the Ancien Regime – Old Europe – was in many ways similar to that of the areas Muslim neighbours, and only moved into the modern world with the eighteenth-century Enlightenment. The author also examines the chances of an Arab spring heralding, after 14 centuries of Old Islam, the entry into the modern democratic world. He argues that the two civilizations are not fundamentally dissimilar, but that they move through comparable stages of development at different moments in time: a difference in chronology rather than in essence.