Passive cooling and thermal management in data centers

  • Conte A.
  • Le Masson S.
  • Louahlia H.
  • Nadjahi C.

This article introduces the first experimental and analytical results of a two-phase thermosyphon loop, designed to cool a data center. This loop, composed by a mini-channels evaporator and an air condenser, is a passive system capable of decreasing electricity consumption in a data center. An analytical model has been developed ...

Cross-correlation based clustering and dimension reduction on multivariate time series for KPIs in a data processing system

  • Egri A.
  • Horváth I.
  • Kovacs F.
  • Molontay R.
  • Varga K.

In this paper, we investigate multi-dimensional time series data and we introduce a graph based clustering approach using the cross-correlation between the time series. The procedure is applied to Key Performance Indicators (KPIs) measured during a specific data processing system in order to identify connections between the various KPIs. The ...

Tailor-made tuneable dielectric and optical characteristics of inorganic electro-chromic materials

  • Bulja S.
  • Kopf R.

Electro-chromic materials (EC) have the ability to reversibly change their optical properties by charge insertion/extraction and have, since their discovery by Deb, been chiefly used in applications related to display technology. Examples are many - smart windows and mirrors and active optical filters being some of them. Owing to their ...

Nonlinear Characterisation for Microstrip Circuits with Low Passive Intermodulation

  • Kozlov Dmitry
  • Schuchinsky A.
  • Shitvov A.

This paper presents a new methodology for experimental charaterisation of distributed nonlinearity in microstrip circuits fabricated on commercial grade microwave laminate materials. The circuits exhibit excessive intermodulation response when subject to relatively high power transmit multi-carrier waveforms. Weak intermodulation products generated in passive circuits may cause strong interference in the ...

Network Service Descriptors as a Factory - Agile Networking for differentiating MSO Business Services

  • Acke W.
  • Fagadar M.
  • Six E.
  • Vanderstraeten H.

Orchestration has become an overloaded word in the industry. While Network Orchestration and Application Orchestration share a lot of technologies coming from the domains of SDN and NFV, the 2 approaches serve different objectives. The paper will specifically address Network Orchestration, aiming at launching new revenue generating Business Connectivity services ...

Sustained Throughput Requirements for Future Residential Broadband Service - Traffic Model for Bandwidth Estimates

  • Kapauan P.
  • Mukhopadhyay A.
  • Wellen J.

This paper presents a model to estimate the 10 years maximum sustained throughput requirements for residential broadband services. The model is used to estimate the maximum throughputs during busy hour and to assess how upper throughput percentiles compare to mean expected value.

High responsivity coherent photonic receiver integrating an SOA, a 90° hybrid and high speed UTC photodiodes

  • Achouche M.
  • Caillaud C.
  • Mekhazni K.
  • Paret J.
  • Pommereau F.
  • Santini G.

We demonstrate a monolithically integrated coherent receiver on an InP substrate with a SOA preamplifier, a 90° optical hybrid and four 40 GHz UTC photodiodes. Record performances with responsivity above 4 A/W with low imbalance <1 dB and error free detection of 32 Gbauds QPSK signals were simultaneously demonstated

Visualization of the wake behind a sliding bubble

  • Davis I.
  • Grennan K.
  • Meehan R.
  • Murray D.
  • Nolan K.

In this work, Schlieren measurements are presented for the wake of an air bubble sliding under a heated, inclined surface in quiescent water to provide new insights into the intricate sliding bubble wake structure and the associated convective cooling process. This is a two-phase flow configuration that is pertinent to ...

Gate-Controlled Kondo Effect in a Single Molecule Transistor with Elliptical Ferromagnetic Leads

  • Hu T.
  • Scott G.

We present low temperature transport measurements of C60-based single molecule transistors fabricated using ferromagnetic break junction devices with planar elliptical leads, revealing a gate-modulated single channel spin-1/2 Kondo effect. The shape anisotropy and dipole interaction of the source and drain electrodes allows for the relative alignment of their respective magnetic ...

Edge Computing in the ePC --- A Reality Check

  • Abe Y.
  • Hadzic I.
  • Woithe H.

Mobile Edge Computing (MEC) has received much attention from the research community in recent years. A significant part of the published work has studied the telecom-centric MEC architecture, which assumes that the computing resource is located at the edge of the mobile access network (e.g., the Evolved Packet Core), typically ...

Over 15-Gb/s MIMO wireless transmission using ultra wideband antennas in SHF band

  • Chen Y.
  • Itoh T.
  • Kaneda N.
  • Li X.
  • Zhu C.

Wireless transmission over 15Gb/s data rate is reported using space diversity MIMO. Multi-diversity planar antennas are designed and fabricated to transmit and receive the radio frequency signal simultaneously in 2 radiation diversities. Reliable 15Gb/s indoor data transmission over 5m distance is demonstrated in the super high frequency band (SHF) between ...

5G E-band backhaul system measurements in urban street-level scenarios

  • Aronkyto K.
  • Du Z.
  • Kapanen J.
  • Ohlmer E.
  • Putkonen J.
  • Swist D.

More than half of the mobile backhaul connections are wireless and huge capacity promise of mmW bands is compelling to cope with the increasing data capacity for future 5G system. We reported a backhaul E-band measurement campaign focusing on radio system measurements with the demonstrator developed in the project. The ...

SDN-based service automation for IoT

  • Chang H.
  • Lakshman T.
  • Mukherjee S.
  • Uddin M.

Bluetooth Low Energy (BLE) is a personal area wireless network technology that is of increasing importance for emerging Internet of Things (IoT) deployments. By design, BLE supports short-range, single-hop communication between a pair of BLE devices. As such, native BLE does not allow network-based policy control or in-network functions for ...

vPROM: VSwitch enhanced programmable measurement in SDN

  • Chen S.
  • Guo Y.
  • Hao F.
  • Lakshman T.
  • Montgomery D.
  • Sriram K.
  • Wang A.

While being critical to the network management, the current state of the art in network measurement is inadequate, providing surprisingly little visibility into detailed network behaviors and often requiring high level of manual intervention to operate. Such a practice becomes increasingly ineffective as the networks grow both in size and ...

Vectoring-Based Dynamic Spectrum Management for G.fast Multi-User Full-Duplex Transmission

  • Lanneer W.
  • Maes J.
  • Moonen M.
  • Tsiaflakis P.

Full-duplex transmission is a new challenging technique emerging in DSL networks that may double the spectral efficiency by transmitting in the downstream (DS) and upstream (US) at the same time on identical frequencies. Unfortunately, this leads to severe near-end crosstalk (NEXT) interference in addition to the conventional far-end crosstalk (FEXT) ...

STAR: Preventing flow-table overflow in software-defined networks

  • Chao H.
  • Guo Z.
  • Gushchin A.
  • Liu R.
  • Walid A.
  • Xu Y.

The emerging Software-Defined Networking (SDN) enables network innovation and flexible control for network operations. A key component of SDN is the flow table at each switch, which stores flow entries that define how to process the received flows. In a network that has a large number of active flows, flow ...

Improving resource efficiency with partial resource muting for future wireless networks

  • Cavalcante R.
  • Liao Q.

We propose novel resource allocation algorithms that have the objective of finding a good tradeoff between resource reuse and interference avoidance in wireless networks. To this end, we first study properties of functions that relate the resource budget available to network elements to the optimal utility and to the optimal ...

Augmenting Practical Cross-layer MAC Schedulers via Offline Reinforcement Learning

  • Peter Danielsen
  • Pianese F.

An automated offline design process for optimized cross-layer schedulers can produce augmented scheduling algorithms tailored to a target deployment scenario. We discuss the application of ODDS, a reinforcement learning technique we introduced, for augmenting LTE MAC scheduler algorithms of practical significance. ODDS observes the correlation between the value of a ...

Near Far Effect on Coded Slotted Aloha

  • Alloum A.
  • Cedric Adjih
  • Ehsan Ebrahimi Khaleghi
  • Paul Muhlethaler

Motivated by scenario requirements for 5G cellular networks, we study one among the protocols candidate to the massive random access: the family of random access methods known as Coded Slotted ALOHA (CSA). Recent body of research has explored aspects of such methods in various contexts, but one aspect has not ...

Dynamic IP Tunneling for Next Generation Mobile Networks

  • Calin D.
  • Kim B.
  • Ling J.
  • Viswanathan H.

The paper describes the principles of a novel mechanism that is aiming at providing unprecedented Quality of Experience (QoE) in next generation mobile networks. The main benefits include: (i) enabling dynamic IP tunnel management (establishing and tearing down) with terminating point in the mobile device instead of the traditional base ...