Spain

Information and communications technologies (ICTs) constitute a market where diverse industries, producers and consumers converge, but also a public space where citizens and organisations live and interact. Although the ICT market is huge and involves a large part of the population, the ICT public space as a social structure where citizens and organisations exercise the right to communicate is fragile and underdeveloped. In this context, this report focuses on appropriateness of technology and locally relevant content, applications and services.Postprint (published version

Building microclouds at the network edge with the Cloudy platform

Edge computing enables new types of services which operate at the network edge. There are important use cases in pervasive computing, ambient intelligence and the Internet of Things (IoT) for edge computing. In this demo paper we present microclouds deployed at the networks edge in the Guifi.net community network leveraging an open extensible platform called Cloudy. The demonstration focuses on the following aspects: The usage of Cloudy for end users, the services of Cloudy to build microclouds, and the application scenarios of IoT data management within microclouds.Peer ReviewedPostprint (author's final draft

Assessing the participatory design of a project-based course on computer network applications

New teaching methodologies which foster student involvement, such as project-based learning, are nowadays part of the study curriculum of many engineering schools. Project-based learning courses, however, often build upon other previously taught technical courses, where the technical content for the project to be developed is studied. That type of course design focuses on building the transversal capabilities of students, and the technical challenges of the project are the mean to acquire these non-technical skills. In this paper, we present and assess a project-based course on computer network applications of a computer science school, which has been designed to improve within the same course both the transversal and technical skills of the students. The proposition of interest is that the course not only aims to train the students’ transversal skills by a group work project, but also to practise new technical topics and technologies. We argue that the key element of the proposed course design is that each student project group defines with the instructor the project they would like to develop in the course. We present first the design of the course and then an assessment with questionnaires, which were conducted over two semesters with the students enrolled in the course. The obtained results indicate that the students achieved both technical and transversal skills, while the instructors need to be flexible to adapt to diverse technical topics of the proposed projects.Peer ReviewedPostprint (published version

Spain

How can we make citizens’ rights effective in the information society? Without a doubt, the answer is: with a wider and more direct participation by citizens. However, the development of the information society is dominated by a commercial and technical perspective that tends to be emphasised to the detriment of other perspectives that are much more important but more difficult to measure. These include: the definition of the rules of the game and the “social contract” (e.g. legal framework), as well as indicators of indirect impact such as production of and access to knowledge, changes in social relations and participation.Postprint (published version

Coordinated detection of forwarding faults in wireless community networks

Wireless Community Networks (WCN) are crowdsourced networks where equipment is contributed and managed by members from a community. WCN have three intrinsic characteristics that make forwarding faults more likely: inexpensive equipment, non-expert administration and openness. These characteristics hinder the robustness of network connectivity. We present KDet, a decentralized protocol for the detection of forwarding faults by establishing overlapping logical boundaries that monitor the behavior of the routers within them. KDet is designed to be collusion resistant, ensuring that compromised routers cannot cover for others to avoid detection. Another important characteristic of KDet is that it does not rely on path information: monitoring nodes do not have to know the complete path a packet follows, just the previous and next hop. As a result, KDet can be deployed as an independent daemon without imposing any change in the network, and it will bring improved network robustness. Results from theoretical analysis and simulation show the correctness of the algorithm, its accuracy in detecting forwarding faults, and a comparison in terms of cost and advantages over previous work, that confirms its practical feasibility in WCN.Peer ReviewedPostprint (author's final draft

P2P architecture for scientific collaboration.

P2P networks are often associated with file exchange applications among private users. However, their features make them suitable for other uses. In this paper we present a P2P architecture for scientific collaboration networks, which takes advantage of the properties inherent in these social networks - small-world, clustering, community structure, assortative mixing, preferential attachment and small and stable groups - in order to obtain better performance, efficient use of resources and system resilience.Peer Reviewe

Object Distribution Networks for World-wide Document Circulation

This paper presents an Object Distribution System (ODS), a distributed system inspired by the ultra-large scale distribution models used in everyday life (e.g. food or newspapers distribution chains). Beyond traditional mechanisms of approaching information to readers (e.g. caching and mirroring), this system enables the publication, classification and subscription to volumes of objects (e.g. documents, events). Authors submit their contents to publication agents. Classification authorities provide classification schemes to classify objects. Readers subscribe to topics or authors, and retrieve contents from their local delivery agent (like a kiosk or library, with local copies of objects). Object distribution is an independent process where objects circulate asynchronously among distribution agents. ODS is designed to perform specially well in an increasingly populated, widespread and complex Internet jungle, using weak consistency replication by object distribution, asynchronous replication, and local access to objects by clients. ODS is based on two independent virtual networks, one dedicated to the distribution (replication) of objects and the other to calculate optimised distribution chains to be applied by the first network

Towards open CSCW systems

Applications designed to support the work of groups will becoming increasingly important to future distributed systems. This paper considers the role of distributed systems within the development of cooperative systems. In particular, we focus on the need to provide Open CSCW systems and their impact on distributed systems. The work currently being undertoken in Open Distributed Systems (ODP) is used to highlight significant trends for future open CSCW systems. It will be shown that the CSCW and ODP community share mutual interests and have complementary aims and goals developed from different perspectives. Within the paper we provide a brief introduction to CSCW highlighting the requirements CSCW places on distributed systems. The development of an environment to support open CSCW systems is introduced and briefly described. Finally, the relationships between requirements and models for Open CSCW systems and the Basic Reference Model of ODP are discussed.Peer ReviewedPostprint (published version

A demand based algorithm for rapid updating of replicas

In many Internet scale replicated system, not all replicas can be dealt with in the same way, since some will be in greater demand than others. In the case of weak consistency algorithms, we have observed that updating first replicas having most demand, a greater number of clients would gain access to updated content in a shorter period of time. In this work we have investigated the benefits that can be obtained by prioritizing replicas with greater demand, and considerable improvements have been achieved. In zones of higher demand, the consistent state is reached up to six times quicker than with a normal weak consistency algorithm, without incurring the additional costs of the strong consistency.Peer Reviewe

A democratic Grid: collaboration, sharing and computing for everyone

This paper presents an integrated vision, architecture, middleware and applications of a public and large scale Grid for everyone: supporting collaboration for groups of people who can interact and share work and share or trade computing resources among them. This public Grid is decentralized and self-adapting to the dynamics of the online world with networks, computers and people who come and go, fail and recover and applications with varying loads and resource needs. Initial evaluation based on the first release of the middleware components and applications shows how our Grid can operate in a dynamic and decentralized environment by a combination of pooling and market mechanisms that adapt supply and demand for resources, self-managing services and applications that react to environmental changes and generic data-sharing services for concurrent write-sharing. The potential for societal impact is enormous as it can open Grid computing and collaboration to everyone on the Internet.Peer ReviewedPostprint (author’s final draft