Catálogo de publicaciones - libros

This paper give a view on key technologies that are emerging as the enabler for evolving Core Transport Network towards the delivery of the customer experience expected by the service users community. Optical technologies will be dealt with first, explaining how they are fitting in the medium and long term evolution of commercial optical transmission systems. Hardware and software technologies involved in the shift toward data centric services are addressed, identifying the path to a full integrated transport and switching core network, with the ultimate objective of maximizing the user benefits and reducing cost.

To transmit and display high quality movies via optical networks, a new Super High Definition (SHD) digital cinema distribution system with the resolution of 8-million pixel is developed. Its image quality is four times of HDTV in resolution, and enables us to replace conventional 35mm films. This system is based on JPEG 2000 coding technology and transmits high quality digital cinema over high-speed IP networks. All digital cinema data are continuously transmitted at up to 500 Mbps. This system opens the door to the next generation of cinema-class digital content distribution over optical networks.

This article presents a view of the needs and developments for the “Next Generation Networks”. It starts from a market and service context following the burst of the Internet bubble and sketches the likely evolution of services by end user type. It is centered, however on a vision of network evolving to architectures necessary to support the needs of operators with special emphasis on the European environment.

This article presents a view of some of the key new technologies that are likely to play a significant role in the deployment of the next generation network architectures necessary to support the needs of operators.

In this paper the authors propose a method to guarantee end-to-end QoS to multiple traffic classes in optical burst switched (OBS) scenario, even in case of network congestion. The OBS network utilizes a core node architecture with no fiber delay lines and a limited set of wavelength converters. Traffic class performance differentiation is achieved by allowing high class traffic to utilize more node functionalities than low class traffic. To improve the likelihood of finding a route, even upon network congestion, bursts are allowed either to be deflected from their default route or to choose from a set of preplanned end-to-end paths. Network performance evaluation is focused on burst blocking probability and end-to-end TCP throughput. Performance is determined under the assumption of exponentially distributed burst interarrival times and arbitrarily distributed burst durations. Numerical results show that the proposed approach is able to guarantee different end-to-end TCP throughput performance to each traffic class. Moreover the proposed burst routing policies allows to decrease, with respect to a shortest path routing policy, the burst blocking probability. Thus the end-to-end TCP throughput is seamlessly guaranteed even in case of network congestion.

Out of order delivery and/or delay jitter are typical phenomena occurring in networks adopting a packet transfer mode and may have a relevant impact on the behavior of higher layer protocols. In this paper an original framework is proposed to analyze these phenomena in optical packet-switched networks that employ the wavelength and the time dimensions to solve congestion. This framework is the first step toward a deeper understanding of the interaction between transport networks and higher layers behaviors.

A novel preamble free optical packet 3R receiver is proposed. Optical packets stream composed of 10Gbit/s preamble-less payload data and arbitrary intervals is generated and received with instantaneous clock and payload data recovery in less than a bit period (<100ps). Preamble-less optical packet clock and data recovery with two hop 40Gbit/s optical packet switching based on all-optical code label processing is experimentally demonstrated.

We come back on a technique to build modular switch nodes. This approach allows for a more cost effective expansion of OPS nodes. We give two example designs, showing that the method is useful only for Broadcast & Select OPS nodes when taking price decrease in function of time into account.

We propose a scheduling algorithm for reducing unused timeslots by considering head gap and tail gap newly generated by assigning a data burst in order to improve the burst loss probability and the throughput performances in Time Sliced Optical Burst Switched (TSOBS) networks. The proposed scheduling algorithm selects the timeslot in which either head gap or tail gap newly generated becomes the minimum. We show that the proposed scheduling algorithm can improve the burst loss probability and the throughput performances as compared with the conventional one.

This paper presents the architecture of WONDER, an advanced ring-based WDM optical packet network designed for high capacity metro environments. The network prototype is currently being developed at PhotonLab in Torino, Italy, by several Italian research groups, thanks to a financing by the Italian Ministry of University and Research (MIUR). It represents an evolution over a similar ring based prototype, named “RingO” which was previously realized in 2001–2002. The WONDER network architecture elaborates on the effectiveness of optics with respect to electronics, trying to identify an optimal mix of the two technologies. We present network architecture, physical topology and node structure of the WONDER prototype, as well as its MAC protocol. The main contribution of this article is the identification of an innovative optical network architecture, which is feasible and cost effective with technologies available today, and can be a valid alternative to more consolidated solutions in metro applications.