Delay is a key Internet performance metric and its stability, variation, and abrupt changes have been well studied.
However, little could have been said about the Internet-wide delay distribution. In order to build a representative sample set for the Internet-wide delay distribution, one needs to draw data from a random selection of source hosts to destination hosts and there is no measurement system with access to every AS and subnet of the Internet. In this work we propose to apply the path-stitching algorithm to archival measurement data and reconstruct the past history of Internet delay distribution. The two main advantages of path stitching are that data from existing measurement projects is sufficient to provide accurate estimates and it produces delay estimates between almost any two hosts in the Internet.
Since the early nineties, intelligent agents and multiagent systems have been envisioned as the key enabling technologies for the design and implementation of large-scale, open, distributed systems. After two decades, the scientific community is still in quest of the killer application that could unleash the full potential of multiagent systems. In recent years, smart infrastructures, such as intelligent transportation and smart power networks, attracted the interest of the scientific community as two paradigmatic large-scale, open, distributed systems of a great social and economical relevance. In particular the talk will focus on two examples of on-going research on the application of market-based methods for the efficient allocation of urban road networks and coalition formation for the creation of virtual power plants.
Seguir leyendo arrow_right_altLogged messages are invaluable for debugging and diagnosing problems. Unfortunately, many execution logs are inscrutable in their raw form. For example, a production Google system may generate a billion-line log file in a single day. In my talk, I will detail two log-analysis tools that I developed to deal with this problem. These tools infer concise and precise models from large execution logs of sequential and distributed systems. Both tools enable new kinds of program analyses and make logs more useful to developers.
Seguir leyendo arrow_right_altWireless communication for intelligent transportation systems (ITSs) is a promising technology to improve driving safety, reduce traffic congestion and support information services in vehicles. A new era of vehicular networks that include vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications is approaching.
Seguir leyendo arrow_right_altEl proyecto MEDIANET (S2009/TIC-1468) organiza una jornada de divulgación de los resultados obtenidos hasta la fecha. En dicha jornada participarán investigadores de los cuatro grupos integrantes del proyecto, quienes presentarán sus trabajos de investigación enmarcados dentro del proyecto. Además, esta jornada servirá también para discutir los retos más importantes que debemos afrontar en Internet, poniendo especial hincapié en los servicios multimedia en la Internet del futuro.
El workshop MEDIANET 2013 se celebrará el próximo 19 de Abril en el campus de Leganés de la Universidad Carlos III de Madrid (sala 4.1.S08 de la Biblioteca Rey Pastor). Las charlas serán en inglés para dar una mayor difusión al evento, que será de libre acceso, aunque se requiere registro previo utilizando el siguiente formulario web http://goo.gl/cuAvB
BitTorrent is currently the dominant Peer-to-Peer (P2P) protocol for file-sharing applications. BitTorrent is also a nightmare for ISPs due to its network agnostic nature, which is responsible for high network transit costs. The research community has deployed a number of strategies for BitTorrent traffic localization, mostly relying on the communication between the peers and a central server called tracker. However, BitTorrent users have been abandoning the trackers in favor of distributed tracking based upon Distributed Hash Tables (DHTs).
Seguir leyendo arrow_right_alt
Give the attendees an evolutionary view on the access networks and open perspectives on the potential developments upcoming. It will always keep an eye on the standardization trends and other ecosystem parameters (as regulation, cost and timeline constrains) in order to provide the attendees the background to further perceive some of the upcoming opted solutions and dynamics.
Seguir leyendo arrow_right_alt
Lugar: Aula de Grados, 5.1.A01, Edificio Padre Soler, Universidad Carlos III de Madrid, Campus de Leganés
Fecha: 15 Octubre, 2008, 9:00 – 19:00
Organización: Cátedra Telefónica de la Universidad Politécnica de Madrid (UPM)
El simposio se celebrará en español
Seguir leyendo arrow_right_altComplex networks, including the Internet, wireless and cellular networks, and on-line social networks, are becoming indispensable parts of our daily lives. These networks arising from a wide range of applications can be represented and studied as graphs, and the underlying link patterns play an important role in understanding and solving problems in such applications. For example, many online social networks, such as Twitter and Google+, can be viewed as directed graphs with uni-directional "following'' relations among users, and the link directions contain crucial information about how users form social communities. In another application, online social networks such as Slashdot and Epinions represent relationships between users as links with positive or negative weights, which correspond to friend and foe relations. These networks are referred to as signed networks, where those signed links generate new challenges in understanding and studying the underlying network properties. In this talk, I present my work on developing theories for studying and characterizing various crucial graph properties, such as the edge directionality in directed graphs and the edge polarity in signed graphs. I do so by emphasizing on applications to detecting stable social communities and understanding social influence propagation patterns on online social networks.
Seguir leyendo arrow_right_altOn 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).
Seguir leyendo arrow_right_alt
Comentarios recientes