Events agenda

7 Feb
2013

PhD Thesis defense: Experimental Analysis of the Socio-Economic Phenomena in the BitTorrent Ecosystem

Michal Kryczka, PhD Student, IMDEA Networks Institute & University Carlos III of Madrid (UC3M), Spain
BitTorrent is the most successful Peer-to-Peer (P2P) application and is responsible for a major portion of Internet traffic. It has been largely studied using simulations, models and real measurements. Although simulations and modelling are easier to perform, they typically simplify analysed problems and in case of BitTorrent they are likely to miss some of the effects which occur in real swarms.
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6 Feb
2013

Silver-lining: a firsthand vision of launching a technological start-up

Vishal Misra, Co-founder & CEO, Silver Lining
Vishal Misra together with Dan Rubinstein launched at the beginning of 2011 the company Silver Lining. This company is a very ambitious tech start-up arising from two professors of Columbia University, and has already attracted a lot of interest and a substantial amount of funding from investors. Silver Lining is developing a very advanced product in the area of content distribution networks that is expected to have high impact. Vishal Misra, co-founder and its current CEO, will give a first-hand account on the development of this interesting initiative.
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4 Feb
2013

Corridor-based routing using opportunistic forwarding in OFDMA multi-hop networks

Alexander Kuehne, Post-doc Researcher, Communications Engineering Lab, Technische Universität Darmstadt, Germany
In multi-hop networks, conventional unipath routing approaches force the data transmission to follow a fixed sequence of nodes. In this talk, we widen this path to create a corridor of forwarding nodes. Within this corridor, data can be split and joined at different nodes as the data travels through the corridor towards the destination node. To split data, decode-and forward OFDMA is used since with OFDMA, one can exploit the benefits of opportunistically allocating different subcarriers to different nodes according to their channel conditions. To avoid interference, each subcarrier is only allocated once per hop. For the presented scheme, the problem of optimizing the network throughput by means of resource and power allocation is formulated and two suboptimal algorithms are proposed to solve this problem with feasible effort. Simulations show that in multi-hop networks corridor-based routing using opportunistic forwarding outperforms conventional unipath routing approaches in terms of achievable throughput.
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30 Jan
2013

The BGP Visibility Scanner

Andra Lutu, PhD Student, IMDEA Networks Institute & University Carlos III of Madrid (UC3M), Spain
By tweaking the BGP configurations, the network operators are able to express their interdomain routing preferences, designed to accommodate a myriad goals. Given the complex interactions between policies in the Internet, the origin AS by itself cannot ensure that only by configuring a routing policy it can also achieve the anticipated results. Moreover, the definition of routing policies is a complicated process, involving a number of subtle tuning operations prone to errors. In this paper, we propose the BGP Visibility Scanner which allows network operators to validate the correct implementation of their routing policies, by corroborating the BGP routing information from approximately 130 independent observation points in the Internet. We exemplify the use of the proposed methodology and also perform an initial validation for the BGP Visibility Scanner capabilities through various real operational use cases.
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23 Jan
2013

Energy Consumption Anatomy of 802.11 Devices and its Implication on Modeling and Design

Andres Garcia-Saavedra, PhD Candidate, NETCOM Research Group, University Carlos III of Madrid, Spain
A thorough understanding of the power consumption behavior of real world wireless devices is of paramount importance to ground energy-efficient protocols and optimizations on realistic and accurate energy models. This paper provides an in-depth experimental investigation of the per-frame energy consumption components in 802.11 Wireless LAN devices. To the best of our knowledge, our measurements are the first to unveil that a substantial fraction of energy consumption, hereafter descriptively named cross-factor, may be ascribed to each individual frame while it crosses the protocol/implementation stack (OS, driver, NIC). Our findings, summarized in a convenient new energy consumption model, contrast traditional models which either neglect or amortize such energy cost component in a fixed baseline cost, and raise the alert that, in some cases, conclusions drawn using traditional energy models may be fallacious.
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16 Jan
2013

Low-Complexity Visible Light Networking with LED-to-LED Communication

Domenico Giustiniano, Senior Researcher and Lecturer, ETH Zurich, Switzerland
Visible Light Communication (VLC) is an emerging technology in which Light Emitting Diodes (LEDs) transport information wirelessly, using the visible light spectrum. While most of the research on VLC has focused on wideband white LEDs used in ambient illumination, narrowband and colored LEDs have received little attention. Short-range free-space optical communication based on narrowband LEDs as visible light transmitters and receivers enable a variety of applications, a scenario we refer as LED-to-LED communication. In this work, we introduce the communication and networking protocols of LED-to-LED communication. Our work addresses fundamental challenges such as efficient collision detection medium access protocol and elimination of light flicker. We build a prototype and demonstrate bi-directional data exchange in a network of up to four LEDs. We further study the trade-offs in the system design and measure the achievable bit-rate and transmission distances
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9 Jan
2013

CROWD Kick-off meeting

Members of the CROWD project
On Jan 8-9, 2013, the kick-off meeting of Research & Development project CROWD (Connectivity management for eneRgy Optimised Wireless Dense networks) was held in Pisa (Italy). CROWD is co-funded by the European Commission within the Seventh Framework Programme (FP7).
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9 Jan
2013

The Next Generation Wireless Sensor Network Challenges for an Emergency Preparedness and Response Class of Applications: A Necessary Public Safety and Security

Prof. Dr. Azzedine Boukerche, Full Professor of Computer Science and Engineering & Canada Research Chair, University of Ottawa, Canada; Chair of Excellence, University Carlos III of Madrid; Visiting Researcher, Institute IMDEA Networks, Spain
Wireless sensor network and wireless multimedia network technologies combined with interactive 3D virtual visualization can converge into really interesting and functional applications such as detailed real-time monitoring of environments, emergency response and preparedness, distributed collaborative training, and remote walkthroughs, just to name a few examples. With the recent advances in wireless communication, and the proliferation of portable computer and micro-sensor devices, we are witnessing a growing interest in using wireless multimedia sensor networks and collaborative virtual environment technologies for safety and security class of applications.
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8 Jan
2013

iBGP Deceptions: More Sessions, Fewer Routes

Luca Cittadini, PhD Student & Collaborator, Dipartimento di Informatica e Automazione, Università degli Studi Roma Tre, Italy
Internal BGP (iBGP) is used to distribute interdomain routes within a single ISP. The interaction between iBGP and the underlying IGP can lead to routing and forwarding anomalies. For this reason, several research contributions aimed at defining sufficient conditions to guarantee anomaly-free configurations and providing design guidelines for network operators.
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19 Dec
2012

Adaptive Modulation for Finite-Horizon Multicasting of Erasure-coded Data

Sim (Allyson) Gek Hong, PhD Student, IMDEA Networks Institute & University Carlos III of Madrid (UC3M), Spain
We design an adaptive modulation scheme to support opportunistic multicast scheduling in wireless networks. Whereas prior work optimizes capacity, we investigate the finite horizon problem where (once or repeatedly) a fixed number of packets has to be transmitted to a set of wireless receivers in the shortest amount of time — a common problem, e.g., for software updates or video multicast.
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