4,214 research outputs found
In the Battle for Reality: Social Documentaries in the U.S.
Provides an overview of documentaries that address social justice and democracy issues, and includes case studies of successful strategic uses of social documentaries
CLOSER: A Collaborative Locality-aware Overlay SERvice
Current Peer-to-Peer (P2P) file sharing systems make use of a considerable percentage of Internet Service Providers (ISPs) bandwidth. This paper presents the Collaborative Locality-aware Overlay SERvice (CLOSER), an architecture that aims at lessening the usage of expensive international links by exploiting traffic locality (i.e., a resource is downloaded from the inside of the ISP whenever possible). The paper proves the effectiveness of CLOSER by analysis and simulation, also comparing this architecture with existing solutions for traffic locality in P2P systems. While savings on international links can be attractive for ISPs, it is necessary to offer some features that can be of interest for users to favor a wide adoption of the application. For this reason, CLOSER also introduces a privacy module that may arouse the users' interest and encourage them to switch to the new architectur
Adaptive Video Streaming Using TCP Factors Control with User Parameters
AbstractMedia streaming over TCP has become increasingly popular because TCP's congestion control provides remarkable stability to the Internet. Streaming over TCP requires adapting to bandwidth availability and other network parameters in order to have a good users satisfaction. Nowadays the streaming video can be projected on different kind of terminal as tablet, smart phones, laptop.etc. Each device has its own characteristics and parameters which must be taken into consideration on the video streaming adaptation process. In this paper, we propose an adaptive video streaming solution to improve the quality of experience (QoE) of the users by adapting TCP parameters to the user parameters on mobile networks. We validate the models using the ns2 simulator
Emerging technologies for learning (volume 1)
Collection of 5 articles on emerging technologies and trend
Network Coding on Heterogeneous Multi-Core Processors for Wireless Sensor Networks
While network coding is well known for its efficiency and usefulness in wireless sensor networks, the excessive costs associated with decoding computation and complexity still hinder its adoption into practical use. On the other hand, high-performance microprocessors with heterogeneous multi-cores would be used as processing nodes of the wireless sensor networks in the near future. To this end, this paper introduces an efficient network coding algorithm developed for the heterogenous multi-core processors. The proposed idea is fully tested on one of the currently available heterogeneous multi-core processors referred to as the Cell Broadband Engine
What's Going on in Community Media
What's Going On in Community Media shines a spotlight on media practices that increase citizen participation in media production, governance, and policy. The report summarizes the findings of a nationwide scan of effective and emerging community media practices conducted by the Benton Foundation in collaboration with the Community Media and Technology Program of the University of Massachusetts, Boston. The scan includes an analysis of trends and emerging practices; comparative research; an online survey of community media practitioners; one-on-one interviews with practitioners, funders and policy makers; and the information gleaned from a series of roundtable discussions with community media practitioners in Boston, Chicago, Minneapolis/St. Paul, and Portland, Oregon
Performance Evaluation And Anomaly detection in Mobile BroadBand Across Europe
With the rapidly growing market for smartphones and user’s confidence for immediate
access to high-quality multimedia content, the delivery of video over wireless networks has
become a big challenge. It makes it challenging to accommodate end-users with flawless
quality of service. The growth of the smartphone market goes hand in hand with the
development of the Internet, in which current transport protocols are being re-evaluated to
deal with traffic growth. QUIC and WebRTC are new and evolving standards. The latter
is a unique and evolving standard explicitly developed to meet this demand and enable
a high-quality experience for mobile users of real-time communication services. QUIC
has been designed to reduce Web latency, integrate security features, and allow a highquality
experience for mobile users. Thus, the need to evaluate the performance of these
rising protocols in a non-systematic environment is essential to understand the behavior
of the network and provide the end user with a better multimedia delivery service. Since
most of the work in the research community is conducted in a controlled environment, we
leverage the MONROE platform to investigate the performance of QUIC and WebRTC
in real cellular networks using static and mobile nodes. During this Thesis, we conduct
measurements ofWebRTC and QUIC while making their data-sets public to the interested
experimenter. Building such data-sets is very welcomed with the research community,
opening doors to applying data science to network data-sets. The development part of the
experiments involves building Docker containers that act as QUIC and WebRTC clients.
These containers are publicly available to be used candidly or within the MONROE
platform. These key contributions span from Chapter 4 to Chapter 5 presented in Part
II of the Thesis.
We exploit data collection from MONROE to apply data science over network
data-sets, which will help identify networking problems shifting the Thesis focus from
performance evaluation to a data science problem.
Indeed, the second part of the Thesis focuses on interpretable data science. Identifying
network problems leveraging Machine Learning (ML) has gained much visibility in the
past few years, resulting in dramatically improved cellular network services. However,
critical tasks like troubleshooting cellular networks are still performed manually by experts
who monitor the network around the clock. In this context, this Thesis contributes by proposing the use of simple interpretable
ML algorithms, moving away from the current trend of high-accuracy ML algorithms
(e.g., deep learning) that do not allow interpretation (and hence understanding) of their
outcome. We prefer having lower accuracy since we consider it interesting (anomalous)
the scenarios misclassified by the ML algorithms, and we do not want to miss them by
overfitting. To this aim, we present CIAN (from Causality Inference of Anomalies in
Networks), a practical and interpretable ML methodology, which we implement in the
form of a software tool named TTrees (from Troubleshooting Trees) and compare it to
a supervised counterpart, named STress (from Supervised Trees). Both methodologies
require small volumes of data and are quick at training. Our experiments using real
data from operational commercial mobile networks e.g., sampled with MONROE probes,
show that STrees and CIAN can automatically identify and accurately classify network
anomalies—e.g., cases for which a low network performance is not justified by operational
conditions—training with just a few hundreds of data samples, hence enabling precise
troubleshooting actions. Most importantly, our experiments show that a fully automated
unsupervised approach is viable and efficient. In Part III of the Thesis which includes
Chapter 6 and 7.
In conclusion, in this Thesis, we go through a data-driven networking roller coaster,
from performance evaluating upcoming network protocols in real mobile networks to
building methodologies that help identify and classify the root cause of networking
problems, emphasizing the fact that these methodologies are easy to implement and can
be deployed in production environments.This work has been supported by IMDEA Networks InstitutePrograma de Doctorado en Multimedia y Comunicaciones por la Universidad Carlos III de Madrid y la Universidad Rey Juan CarlosPresidente: Matteo Sereno.- Secretario: Antonio de la Oliva Delgado.- Vocal: Raquel Barco Moren
A Credit-based Home Access Point (CHAP) to Improve Application Quality on IEEE 802.11 Networks
Increasing availability of high-speed Internet and wireless access points has allowed home users to connect not only their computers but various other devices to the Internet. Every device running different applications requires unique Quality of Service (QoS). It has been shown that delay- sensitive applications, such as VoIP, remote login and online game sessions, suffer increased latency in the presence of throughput-sensitive applications such as FTP and P2P. Currently, there is no mechanism at the wireless AP to mitigate these effects except explicitly classifying the traffic based on port numbers or host IP addresses. We propose CHAP, a credit-based queue management technique, to eliminate the explicit configuration process and dynamically adjust the priority of all the flows from different devices to match their QoS requirements and wireless conditions to improve application quality in home networks. An analytical model is used to analyze the interaction between flows and credits and resulting queueing delays for packets. CHAP is evaluated using Network Simulator (NS2) under a wide range of conditions against First-In-First- Out (FIFO) and Strict Priority Queue (SPQ) scheduling algorithms. CHAP improves the quality of an online game, a VoIP session, a video streaming session, and a Web browsing activity by 20%, 3%, 93%, and 51%, respectively, compared to FIFO in the presence of an FTP download. CHAP provides these improvements similar to SPQ without an explicit classification of flows and a pre- configured scheduling policy. A Linux implementation of CHAP is used to evaluate its performance in a real residential network against FIFO. CHAP reduces the web response time by up to 85% compared to FIFO in the presence of a bulk file download. Our contributions include an analytic model for the credit-based queue management, simulation, and implementation of CHAP, which provides QoS with minimal configuration at the AP
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