Giorgio Parladori

Energy Efficiency in integrated IT and optical network infrastructures: The GEYSERS approach

In this paper we propose energy efficient design and operation of infrastructures incorporating integrated optical network and IT resources. For the first time we quantify significant energy savings of a complete solution jointly optimizing the allocation and provisioning of both network and IT resources. Our approach involves virtualization of the infrastructure resources and it is proposed and developed in the framework of the European project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services.

Energy efficiency considerations in integrated IT and optical network resilient infrastructures

The European Integrated Project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services - is concentrating on infrastructures incorporating integrated optical network and IT resources in support of the Future Internet with special emphasis on cloud computing. More specifically GEYSERS proposes the concept of Virtual Infrastructures over one or more interconnected Physical Infrastructures comprising both network and IT resources. Taking into consideration the energy consumption levels associated with the ICT today and the expansion of the Internet in size and complexity, that incurring increased energy consumption of both IT and network resources, energy efficient infrastructure design becomes critical. To address this need, in the framework of GEYSERS, we propose energy efficient design of infrastructures incorporating integrated optical network and IT resources, supporting resilient end-to-end services. Our modeling results quantify significant energy savings of the proposed solution by jointly optimizing the allocation of both network and IT resources.

Self-seeded RSOAs WDM PON field trial for business and mobile fronthaul applications

GEth, CPRI and 10 Gbit/s transmissions are experimented using amplified and standard self-seeded RSOA WDM PON systems. A field trial setup was exploited to test the system performance in terms of reach and optical budget.

Performance comparison between electrical copper-based and optical fiber-based backplanes

A performance comparison between the electrical Cu-based backplane and a full-optical fiber-based backplane is presented in terms of capacity and power consumption. By means of systematic simulations we find the electrical configuration, which allows to optimize the Cu-based backplane by exploiting the best technologies available today. On the other hand, a fiber-based optical backplane is proposed by exploiting the most performing VCSEL sources. Limitations of the electrical and optical approaches are discussed, considering their capabilities to support up to about 25-Gb/s transmission and the possibility to evolve towards higher bit-rates.

125-km Long Cavity Based on Self-Seeded RSOAs Colorless Sources for 2.5-Gb/s DWDM Networks

The laser behavior of reflective semiconductor optical amplifier self-seeded sources is investigated. 2.5-Gb/s transmission is realized with optical cavities of 10, 26, 100, and 125 km for access and metropolitan networks, realizing the longest amplified self-seeded external cavity laser. Moreover, Gigabit Ethernet, common public radio interface, and 2.5-Gb/s transmissions are experimented using amplified self-seeded reflective semiconductor optical amplifier wavelength division multiplexing passive optical networks systems. A field trial setup is exploited to test the system performance in terms of reach and optical budget.

Energy efficiency in optical networks

This paper proposes a new framework, specifically designed for introducing and suitably managing/using green metrics in ASON/GMPLS Optical Transport Networks (OTNs). The core element of such a framework is the Green Abstraction Layer (GAL), a standard interface proposed by the ECONET project, which has been specifically designed to give a simplified a common view of power management primitives available in next-generation green network equipment. The Green Abstraction Layer allows to extract available power management settings, and to set the desired configuration into a device, hiding heterogeneous and complex details of device internal physical architecture of nodes.

WDM PON RSOA-based self-tuning transmitters: An insight from the EU FP7 ERMES project

We present the final results of the EU FP7 ERMES project, which focused on the development of a WDM-PON colourless self-tuning transmitter based on RSOA self-seeding. Measurements obtained with a packaged O-band RSOA in a SFP+ compatible transmitter are reported at 1.25, 2.5 and 10 Gb/s for various drop fibre lengths, up to 6.3 km and 1 km respectively. We successfully demonstrated transmission over more than 20-km SSMF with bit error rates below the FEC limit (3·10-3). The transmission length is limited only by the power budget while the chromatic dispersion has no impact, even at 10 Gb/s. Finally, we give an overview of the BER field trail measures performed with the 18-km fibre loops over the city of Lannion (France). We tested the ERMES transmitter at 2.5 Gb/s and 10 Gb/s with various PRBS lengths to prepare GEth and CPRI tests. Field trial results resembled laboratory tests, successfully obtaining transmission over up to 2 fibre loops.

Energy-aware weight assignment framework for circuit oriented GMPLS networks

A branch of green networking research is consolidating. It aims at routing traffic with the goal of reducing the network energy consumption. It is usually referred to as Energy-Aware Routing. Previous works in this branch only focused on pure IP networks, e.g., assuming an Open Shortest Path First (OSPF) control plane, and best effort packet forwarding on the data plane. In this work, we consider instead Generalized Multi-Protocol Label Switching (GMPLS) backbone networks, where optical technologies allow to design “circuit switching” network management policies with strict bandwidth reservation policies. We define a simple and generic framework which generates a family of routing algorithms, based on an energy-aware weight assignment. In particular, routing weights are functions of both the energy consumption and the actual load of network devices. Using such weights, a simple minimum-cost routing allows finding the current least expensive circuit, minimising the additional energy cost. Results obtained on realistic case studies show that our weight assignment policy favours a consistent reduction of the network power consumption, without significantly affecting the network performance. Furthermore, the framework allows to trade energy efficiently and network performance, a desirable property at which ISPs are looking for. Simple and robust parameter settings allow reaching a win-win situation, with excellent performance in terms of both energy efficiency and network resource utilization.

Reducing emissions of core networks: A comparative analysis

Networks Operators unanimously agree on the need to reduce power consumption of their networks. Motivation behind is surely related to the need to minimize the operating costs, gaining competitiveness. However this is also in line with the growing attention to the CO2 emission.

Preprocessing for the MPEG-2 video coding

The use of compression algorithms at low bit-rate often introduce annoying artifacts. It is possible to overcome the limit of the encoding process with a suitable preprocessing of the input image sequence, in order to reduce the bit-rate at a given picture quality or improve the picture quality at a given bit-rate. In this paper, a preprocessing technique is developed in order to improve the performance of the MPEG-2 encoder operation by evaluating, pixel by pixel, the motion characteristics and the luminance gradients in images of a sequence and deriving from this information the parameters to control an adaptive filter.