1,720,965 research outputs found
A Questionnaire based Examination of Community Networks
Full text linkThere is a variety of community networks out there. In this paper we try to shed a light on the community network landscape by presenting the results of a questionnaire filled in by different community network organisations around the world. We demonstrate the variety of infrastructure used and the different management approaches of the network within those communities. We also show the common challenges of the communities and provide pointers to tackle those challenges
Experimental Evaluation of Wireless Mesh Networks: A Case Study and Comparison
Full text linkPrice of WiFi devices has decreased dramatically in recent years, while new standards, as 802.11n, have multiplied its performance. This has fostered the deployment of Wireless Mesh networks (WMN), putting into practice concepts evolved from more than a decade of research in Ad Hoc networks. Nevertheless, evolution of WMN it is in its infancy, as shows the growing and diverse number of scenarios where WMN are being deployed. In these paper we analyze a particular case study of a Wireless Community Mesh Network, and we compare it with a selected experimental WMN studies found in the literature
Experimental evaluation of a wireless community mesh network
Full text linkNowadays there are inexpensive WiFi devices that have fostered the deployment of wireless communities. Well known routing protocols used in the Internet do not fit well to time varying characteristic of wireless networks. This has motivated an intensive research on routing protocols for wireless mesh networks. At this time there are a number of mature and stable implementations that are being deployed in production networks. In this paper we focus on the experimental evaluation of a production Wireless Mesh network being deployed in a testbed at Universitat Politècnica de Catalunya (UPC) and a quarter of the city of Barcelona, Spain. To our best knowledge, this is the first paper where a production community wireless network using 802.11an is analyzed
On the Topology Characterization of Guifi.net
Full text linkIn this paper it is analyzed the topology of Guifi.net Wireless Community Network (WCN). WCN have emerged in recent years organized and deployed by the cooperation of its own customers. WCN keep parallelisms with the construction of the Internet, and seems logical to look for common characteristics among them. More specifically, it is investigated whether there are topology patterns of Guifi.net, and to what extend they share the power-law properties that have been found to obey many topology parameters of the Internet. The paper also proposes a topology generator algorithm that it is able to reproduce specific graph properties that have been obtained for Guifi.net
Distance progress based opportunistic routing for wireless mesh networks
No full textOpportunistic Routing (OR) has been proposed to improve the performance of multihop wireless networks by
exploiting its broadcast nature. In contrast to traditional routing,
where traffic is sent along pre-determined paths, in OR an
ordered set of candidates is selected as the next-hop potential
forwarders. The candidate selection is a key issue in OR and
many algorithms have been proposed in the literature. In this
paper, we define a new metric for candidate selection based on
the expected distance progress of sending a packet under OR. By
using this metric we propose a hop-by-hop candidate selection
and prioritization algorithm that we call
Distance Progress Based
Opportunistic Routing
, DPOR. In contrast to other algorithms,
in DPOR each node selects its candidates set independently,
without considering the other nodes’ candidates sets. DPOR only
relies on the neighbors’ geographic position of forwarder and the
links delivery probability between forwarder and its neighbors.
We compare our proposal with four other relevant candidate
selection algorithms. Our results show that DPOR performance
is almost the same as optimum candidate selection algorithm,
while DPOR requires less information and run much fasterPeer ReviewedPostprint (published version
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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