Energy-efficiency improvements for optical access

This article discusses novel approaches to improve energy efficiency of different optical access technologies, including time division multiplexing passive optical network (TDM-PON), time and wavelength division multiplexing PON (TWDM-PON), point-to-point (PTP) access network, wavelength division multiplexing PON (WDM-PON), and orthogonal frequency division multiple access PON (OFDMA-PON). These approaches include cyclic sleep mode, energy-efficient bit interleaving protocol, power reduction at component level, or frequency band selection. Depending on the target optical access technology, one or a combination of different approaches can be applied

Performance analysis of Energy Efficient Ethernet on video streaming servers

[EN] Current trends on traffic growth oversee a steady increase of video streaming services, and the subsequent development of the associated infrastructure to allocate and distribute such contents. One of the operational costs associated to this infrastructure is the power bill. Therefore any mechanism used to decrease it, reducing also the carbon footprint asso- ciated to it, is welcome. In this work we investigate the suitability of the recently standard- ized IEEE 802.3az Energy Efficient Ethernet (EEE) for video traffic generated by video- streaming servers. The conclusion of the analysis is positive about the achievable energy savings, due to the inherent features of traffic patterns of video-streaming servers which help reducing the number of transitions between active and low-power modes in EEE.Part of the research leading to these received funding from the European Community's Seventh Framework Programme (FP7-ICT-2009-5) under Grant agreement No. 258053 (MEDIEVAL project). Additionally, the authors would like to acknowledge the support to this work by the CAM-UC3M Greencom Research Grant (under code CCG10-UC3M/TIC-5624), the FIERRO Spanish project (TEC2010-12250-E) and the Google Research Award "New Protocol Semantics and Scheduling Primitives for Energy Efficiency: Burst Coalescing at the Link and Application Layers".De La Oliva, A.; Vargas Hernández, TR.; Guerri Cebollada, JC.; Alberto Hernandez, J.; Reviriego, P. (2012). Performance analysis of Energy Efficient Ethernet on video streaming servers. Computer Networks. 57(3):599-608. https://doi.org/10.1016/j.comnet.2012.09.019S59960857

Optimum traffic allocation in bundled energy-efficient ethernet links

The energy demands of Ethernet links have been an active focus of research in the recent years. This work has enabled a new generation of energy-efficient Ethernet (EEE) interfaces able to adapt their power consumption to the actual traffic demands, thus yielding significant energy savings. With the energy consumption of single network connections being a solved problem, in this paper, we focus on the energy demands of link aggregates that are commonly used to increase the capacity of a network connection. We build on known energy models of single EEE links to derive the energy demands of the whole aggregate as a function on how the traffic load is spread among its powered links. We then provide a practical method to share the load that minimizes overall energy consumption with controlled packet delay and prove that it is valid for a wide range of EEE links. Finally, we validate our method with both synthetic and real traffic traces captured in Internet backbones.Xunta de Galici

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