Energy Profiling of ISP Points of Presence

Points of Presence (PoP), large aggregation nodes of a telecommunication network in which users lines are inter- connected to the ISP backbone network, are relevant elements of the ISP network infrastructure. Motivated by the today interest of both ISPs and researchers to more energy efficient Internet, we investigate the power consumption of PoPs of FASTWEB, a national-wide ISP in Italy. Energy profiling spans a period of one year, and includes both ADSL and FTTH access technologies. This extensive and unique dataset allows us to shed light on energy consumption of ISP networks, which we profile against other measurements, such as external temperature and PoP handled traffic. Results show that energy consumption is independent on the traffic, while it is strongly correlated with both daily and annual variability of temperature, due to air conditioning energy cost. Starting from these results, we investigate some possible strategies to reduce ISP electricity bill. We consider the adoption of energy proportional architectures which are currently being investigated by both manufacturers and researchers. Moreover, we evaluate the possible energy savings using real traffic data and we obtain that simple PoPs energy saving models based on two-three energy operating configuration can achieve results comparable to fully energy proportional mode

Traffic grooming and energy-efficiency in flexible-grid networks

Energy-efficient design of flexible-grid networks is investigated. We focus on the design of the logical layer, usually disregarded when dealing with flexible-grid networks. More precisely, we evaluate the impact of introducing an energy-aware electronic traffic grooming in flexible-grid networks design. We propose two greedy heuristics for the network design, one exploiting traffic grooming, and we compare their energy efficiency. Results have been retrieved for several randomly generated networks of different size, with different connectivity, average physical link length and traffic scenarios. Significant energy savings can be achieved for low traffic loads and large network size when performing traffic grooming

Power-Aware Logical Topology Design Heuristics in Wavelength-Routing Networks

Abstract—Wavelength-Routing (WR) networks are the most common solution for core networks. With the access segment moving from copper to Passive Optical Networks (PON), core networks will become one of the major culprits of Internet power consumption. However, WR networks offer some design flexibility which can be exploited to mitigate their energy requirements. One of the main steps which has to be faced in designing WR networks is the planning of the Logical Topology (LT) starting from the matrix of traffic requests. In this paper, we propose a Mixed Integer Linear Programming (MILP) formulation to find power-wise optimal LTs. In addition, due to the complexity of the MILP approach we propose a greedy heuristic and a genetic algorithm (GA) ensuring performance close to the one achieved by the MILP formulation. I

Energy-Efficient Design of Wavelength-Routing Networks

We discuss the power-aware Logical Topology Design problem in wavelength routing net- works, and analyze the economical impacts of power-efficiency. Results show that energy-optimized logical topologies can bring significant economical saving

Energy efficiency in access and aggregation networks: From current traffic to potential savings

Access and aggregation networks account nowadays for a large share of the consumed energy in communication networks, and actions to ameliorate their energy cost are under investigation by the research community. In this work, we present a study of the possible savings that could be achieved if such technologies were in place. We take advantage of large datasets of measurements collected from the network of FASTWEB, a national-wide Internet Service Provider in Italy. We first perform a detailed characterization of the energy consumption of Points of Presence (PoPs) investigating on how factors such as external temperature, cooling technology and traffic load influence the consumed energy. Our mea- surements precisely quantify how the power consumption in today networks is practically independent from the traffic volume, while it is correlated only with the external temper- ature. We then narrow down our analysis to consider the traffic generated by each house- hold. More specifically, by observing about 10,000 ADSL customers, we characterize the typical traffic patterns generated by users who access the Internet. Using the available real data, we thus investigate if the energy consumption can be sig- nificantly reduced by applying simple energy-efficient policies that are currently under studies. We investigate energy-to-traffic proportional and resource consolidation technol- ogies for the PoP, while sleep modes policies are considered at the ADSL lines. All these energy-efficient policies, even if they are not yet available, are currently being widely investigated by both manufacturers and researchers. At the PoP level, our dataset shows that it would be possible to save up to 50% of energy, and that even simple mechanisms would easily allow to save 30% of energy. Considering the ADSL lines, it results that sleep mode policies can be effectively implemented, reducing the energy consumption of ADSL modems with little or marginal impact on the Quality of Service offered to users. We make available all datasets used in this paper to allow other researchers to benchmark their pro- posals considering actual traffic traces

Energy Efficient Content Distribution in an ISP Network

International audienceWe study the problem of reducing power consump- tion in an Internet Service Provider (ISP) network by designing the content distribution infrastructure managed by the operator. We propose an algorithm to optimally decide where to cache the content inside the ISP network. We evaluate our solution over two case studies driven by operators feedback. Results show that the energy-efficient design of the content infrastructure brings substantial savings, both in terms of energy and in terms of bandwidth required at the peering point of the operator. Moreover, we study the impact of the content characteristics and the power consumption models. Finally, we derive some insights for the design of future energy-aware networks

TREND towards more energy-efficient optical networks

International audienceWith one third of the world population online in 2013 and an international Internet bandwidth multiplied by more than eight since 2006, the ICT sector is a non-negligible contributor of worldwide greenhouse gases emissions and power consumption. Indeed, power consumption of telecommunication networks has become a major concern for all the actors of the domain, and efforts are made to reduce their impact on the overall figure of ICTs, and to support its foreseen growth in a sustainable way. In this context, the contributors of the European Network of Excellence TREND have developed innovative solutions to improve the energy efficiency of networks. This paper gives an overview of the solutions related to optical networks

Diets including Animal Food Are Associated with Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a clinical condition with a prevalence of up to 25% in Western countries. Typical GERD symptoms include heartburn and retrosternal regurgitation. Lifestyle modifications, including diet, are considered a first-line therapeutic approach. To evaluate the impact of life habits on GERD in this cross-sectional study, we used data collected through an online survey from 1146 participants. GERD was defined according to the Montreal Consensus. For all participants, clinical and lifestyle characteristics were recorded. Overall, 723 participants (63.1%) consumed a diet including animal food (non-vegans), and 423 participants (36.9%) were vegans. The prevalence of GERD was 11% (CI 95%, 9–14%) in non-vegans and 6% (CI 95%, 4–8%) in vegans. In the multivariate analysis, after adjusting for confounding factors, subjects on a non-vegan diet were associated with a two-fold increase in the prevalence of GERD compared to vegans (OR = 1.96, CI 95%, 1.22–3.17, p = 0.006). BMI and smoking habits were also significantly associated with GERD. This study shows that an animal food-based diet (meat, fish, poultry, dairy, and eggs) is associated with an increased risk of GERD compared to a vegan diet. These findings might inform the lifestyle management of patients with GERD-related symptoms

Energy Efficient Content Distribution in an ISP Network

International audienceWe study the problem of reducing power consump- tion in an Internet Service Provider (ISP) network by designing the content distribution infrastructure managed by the operator. We propose an algorithm to optimally decide where to cache the content inside the ISP network. We evaluate our solution over two case studies driven by operators feedback. Results show that the energy-efficient design of the content infrastructure brings substantial savings, both in terms of energy and in terms of bandwidth required at the peering point of the operator. Moreover, we study the impact of the content characteristics and the power consumption models. Finally, we derive some insights for the design of future energy-aware networks

The continuity of effect of schizophrenia polygenic risk score and patterns of cannabis use on transdiagnostic symptom dimensions at first-episode psychosis: findings from the EU-GEI study

Abstract: Diagnostic categories do not completely reflect the heterogeneous expression of psychosis. Using data from the EU-GEI study, we evaluated the impact of schizophrenia polygenic risk score (SZ-PRS) and patterns of cannabis use on the transdiagnostic expression of psychosis. We analysed first-episode psychosis patients (FEP) and controls, generating transdiagnostic dimensions of psychotic symptoms and experiences using item response bi-factor modelling. Linear regression was used to test the associations between these dimensions and SZ-PRS, as well as the combined effect of SZ-PRS and cannabis use on the dimensions of positive psychotic symptoms and experiences. We found associations between SZ-PRS and (1) both negative (B = 0.18; 95%CI 0.03–0.33) and positive (B = 0.19; 95%CI 0.03–0.35) symptom dimensions in 617 FEP patients, regardless of their categorical diagnosis; and (2) all the psychotic experience dimensions in 979 controls. We did not observe associations between SZ-PRS and the general and affective dimensions in FEP. Daily and current cannabis use were associated with the positive dimensions in FEP (B = 0.31; 95%CI 0.11–0.52) and in controls (B = 0.26; 95%CI 0.06–0.46), over and above SZ-PRS. We provide evidence that genetic liability to schizophrenia and cannabis use map onto transdiagnostic symptom dimensions, supporting the validity and utility of the dimensional representation of psychosis. In our sample, genetic liability to schizophrenia correlated with more severe psychosis presentation, and cannabis use conferred risk to positive symptomatology beyond the genetic risk. Our findings support the hypothesis that psychotic experiences in the general population have similar genetic substrates as clinical disorders