150,720 research outputs found
Review of Waste Heat Utilisation from Data Centres
Rapidly increasing global internet traffic, mobile internet users and the number of Internet of
Things (IoT) connections are driving exponential growth in demand for data centre and
network services, which in turn is driving their electricity demand. Data centres now account
for 3% of global electricity consumption and contribute to 4% of the global greenhouse gas
emissions. This study discusses the potential of reusing the waste heat from data centres. An
overview of imbedding heat recovery systems into data centres is presented. The implications
of economic cost and energy efficient heat recovery systems in data centre buildings are also
discussed. The main problems with implementing heat recovery systems in existing data
centre designs are (i) high capital costs of investment and (ii) low temperatures of the waste
heat. This study suggests alternatives that could allow data centre operators to utilise waste
heat with more efficiencies. It also discusses how liquid-cooled data centres can be more
efficient in utilising their waste heat than the air-cooled ones. One possible solution suggested
here is that data centre operators can decrease their environmental impact by exporting waste
heat to the external heat networks. The barriers in connecting datacentres to heat networks are
discussed and suggestions to overcome those barriers have been provided
Assessment of real-time data transmission via ad-hoc communication networks in the North Atlantic oceanic airspace
Data link based real-time data transmission for air traffic services and aeronautical operational control provides for safe, efficient and timely exchange of information between aircraft and ground entities within the current air transportation system. This enables procedures and process optimization for air traffic service and airline
operational control. Currently, the air transport system relies on direct line-of-sight data link in continental airspace and communication via satellite or high frequency data link in oceanic, remote or polar airspace. Future communication technology intends to additionally allow for indirect air-to-ground communication via
aeronautical ad-hoc networks using aircraft as network nodes. This approach bears a high potential to increase airspace capacity and efficiency for congested airspaces with little ground infrastructure as it is the case e.g. for the North Atlantic oceanic airspace. While the assessment of operational benefits for conventional line-ofsight or satellite-based data link technologies can be based on the experience made with existing technologies, the assessment of aeronautical ad-hoc networks needs careful consideration of the particular air traffic situation as well as of the specific aeronautical communication demand. In our work we present a method to
combine air traffic and connectivity simulations with an aeronautical data traffic demand model for the North Atlantic oceanic airspace. As a result, the coverage of aeronautical data traffic demand by an aeronautical adhoc network enabled by the new technology, will be estimated for various scenarios for the North Atlantic oceanic airspace. Dependencies on the equipage fraction and on the air-to-air radio range will be analyzed. Also, expected application data rates at aircraft exchanging the data communication of the airborne network with ground entities, will be assessed on a simplified basis. The results are suited to serve as a technical guidance for further scaling and definition of the underlying air-to-air data link technology
Increasing resilience of ATM networks using traffic monitoring and automated anomaly analysis
Systematic network monitoring can be the cornerstone for
the dependable operation of safety-critical distributed
systems. In this paper, we present our vision for informed
anomaly detection through network monitoring and
resilience measurements to increase the operators'
visibility of ATM communication networks. We raise the
question of how to determine the optimal level of
automation in this safety-critical context, and we present a
novel passive network monitoring system that can reveal
network utilisation trends and traffic patterns in diverse
timescales. Using network measurements, we derive
resilience metrics and visualisations to enhance the
operators' knowledge of the network and traffic behaviour,
and allow for network planning and provisioning based on
informed what-if analysis
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