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Vrijders S.,Ghent University | Staessens D.,Ghent University | Colle D.,Ghent University | Salvestrini F.,NeXtworks | And 3 more authors.
IEEE Network | Year: 2014

In recent years, many new Internet architectures are being proposed to solve shortcomings in the current Internet. A lot of these new architectures merely extend the current TCP/IP architecture and hence do not solve the fundamental cause of these problems. The Recursive Internet Architecture (RINA) is a true new network architecture, developed from scratch, building on lessons learned in the past. RINA prototyping efforts have been ongoing since 2010, but a prototype on which a commercial RINA implementation can be built has not been developed yet. The goal of the IRATI research project is to develop and evaluate such a prototype in Linux/OS. This article focuses on the software design required to implement a network stack in Linux/OS. We motivate the placement of, and communication between, the different software components in either the kernel or user space. The first open source prototype of the IRATI implementation of RINA will be available in June 2014 for researchers, developers, and early adopters. © 1986-2012 IEEE.


Ludovici A.,Polytechnic University of Catalonia | Calveras A.,Polytechnic University of Catalonia | Calveras A.,I2Cat Foundation
Sensors (Switzerland) | Year: 2015

In this paper, we present the design of a Constrained Application Protocol (CoAP) proxy able to interconnect Web applications based on Hypertext Transfer Protocol (HTTP) and WebSocket with CoAP based Wireless Sensor Networks. Sensor networks are commonly used to monitor and control physical objects or environments. Smart Cities represent applications of such a nature. Wireless Sensor Networks gather data from their surroundings and send them to a remote application. This data flow may be short or long lived. The traditional HTTP long-polling used by Web applications may not be adequate in long-term communications. To overcome this problem, we include the WebSocket protocol in the design of the CoAP proxy. We evaluate the performance of the CoAP proxy in terms of latency and memory consumption. The tests consider long and short-lived communications. In both cases, we evaluate the performance obtained by the CoAP proxy according to the use of WebSocket and HTTP long-polling. © 2015 by the authors; licensee MDPI, Basels, Switzerland.


Garcia-Lozano M.,Polytechnic University of Catalonia | Lema M.A.,Polytechnic University of Catalonia | Ruiz S.,Polytechnic University of Catalonia | Minerva F.,I2Cat Foundation
IEEE Transactions on Broadcasting | Year: 2011

The numerous advantages of single-frequency networks (SFNs) make them one of the preferred deployment options for digital video broadcasting terrestrial (DVB-T) operators. However, SFNs are exposed to self-interference that may reduce the effective coverage. This work deals with the optimal adjustment of internal delays at the transmitters to minimize areas with this problem. The use of metaheuristics is proposed to define a feasible automatic process that allows an intelligent exploration of the space of solutions. Several realistic scenarios in the northeast of Spain have been successfully solved and the quality of solutions has been quantified against other resolution methods. Details on how to adjust the parameters of the algorithms along with practical implementation issues are also addressed. © 2011 IEEE.


Betzler A.,i2CAT Foundation | Gomez C.,Polytechnic University of Catalonia | Demirkol I.,Polytechnic University of Catalonia | Paradells J.,Polytechnic University of Catalonia
IEEE Communications Magazine | Year: 2016

CoAP is a lightweight RESTful application layer protocol devised for the IoT. Operating on top of UDP, CoAP must handle congestion control by itself. The core CoAP specification defines a basic congestion control mechanism, but it is not capable of adapting to network conditions. However, IoT scenarios exhibit significant resource constraints, which pose new challenges on the design of congestion control mechanisms. In this article we present CoCoA, an advanced congestion control mechanism for CoAP being standardized by the Internet Engineering Task Force CoRE working group. CoCoA introduces a novel round-trip time estimation technique, together with a variable backoff factor and aging mechanisms in order to provide dynamic and controlled retransmission timeout adaptation suitable for the peculiarities of IoT communications. We conduct a comparative performance analysis of CoCoA and a variety of alternative algorithms including state-of-the-art mechanisms developed for TCP. The study is based on experiments carried out in real testbeds. Results show that, in contrast to the alternative methods considered, CoCoA consistently outperforms the default CoAP congestion control mechanism in all evaluated scenarios. © 1979-2012 IEEE.


Betzler A.,I2CAT Foundation | Gomez C.,Polytechnic University of Catalonia | Demirkol I.,Polytechnic University of Catalonia
PE-WASUN 2015 - Proceedings of the 12th ACM Symposium on Performance Evaluation of Wireless Ad Hoc, Sensor, and Ubiquitous Networks | Year: 2015

Networks of constrained devices play an important role in the Internet of Things (IoT). In such networks congestion may lead to significant performance decrease and is a recurring phenomenon given the restricted hardware capacities of constrained devices and the limitations of low-power radios. The Constrained Application Protocol (CoAP) designed for IoT communications defines a basic congestion control mechanism for the exchange of messages with end-to-end reliability between two endpoints. Yet, for transmissions without end-to-end reliability the CoAP base specification does not determine any congestion control mechanism. Proposals for congestion control mechanisms for unreliable CoAP communications are made in the CoAP observe and CoAP Simple Congestion Control/Advanced (CoCoA) Internet drafts, which introduce a static and a dynamic rate limitation for outgoing messages, respectively. In this paper experimental evaluations are carried out to determine the performance of the different proposals. We find out that, in contrast with the other analyzed approaches, CoCoA is able to maintain high performance in all the analyzed scenarios, thanks to its adaptive nature. © 2015 ACM.


Ferrandiz-Lahuerta J.,I2CAT Foundation | Camps-Mur D.,I2CAT Foundation | Paradells-Aspas J.,Polytechnic University of Catalonia
2015 IEEE Global Communications Conference, GLOBECOM 2015 | Year: 2015

In this paper we introduce a novel reliable asynchronous protocol that allows to establish a VLC link between a LED luminary and an off-the- shelf smartphone. Our protocol and decoding algorithms benefit from the access to advanced camera settings available in the latest generations of mobile devices to outperform previous VLC designs in the state of the art. In particular, in the paper we provide an experimental evaluation using a commercial Nexus 5 device where it is shown how our designed prototype can achieve transmission speeds of up to 700 bps and operating distances of up to 3 meters. The previous performance figures have the potential to spark a wide set of novel applications. © 2015 IEEE.


Demchenko Y.,University of Amsterdam | De Laat C.,University of Amsterdam | Lopez D.R.,RedIRIS | Garcia-Espin J.A.,I2CAT Foundation
Proceedings - 2nd IEEE International Conference on Cloud Computing Technology and Science, CloudCom 2010 | Year: 2010

Modern e-Science and high technology industry require high-performance and complicated network and computer infrastructure to support distributed collaborating groups of researchers and applications that should be provisioned on-demand. The effective use and management of the dynamically provisioned services can be achieved by using the Service Delivery Framework (SDF) proposed by TeleManagement Forum that provides a good basis for defining the whole services life cycle management and supporting infrastructure services. The paper discusses conceptual issues, basic requirements and practical suggestions for provisioning consistent security services as a part of the general e-Science infrastructure provisioning, in particular Grid and Cloud based. The proposed Security Services Lifecycle Management (SSLM) model extends the existing frameworks with additional stages such as "Reservation Session Binding" and "Registration and Synchronisation" that specifically target such security issues as the provisioned resources restoration, upgrade or migration and provide a mechanism for remote executing environment and data protection by binding them to the session context. The paper provides a short overview of the existing standards and technologies and refers to the ongoing projects and experience in developing dynamic distributed security services. © 2010 IEEE.


Afaqui M.S.,Polytechnic University of Catalonia | Garcia-Villegas E.,Polytechnic University of Catalonia | Lopez-Aguilera E.,Polytechnic University of Catalonia | Camps-Mur D.,I2CAT Foundation
2016 IEEE International Conference on Communications, ICC 2016 | Year: 2016

The popularity and wider acceptance of IEEE 802.11 based WLANs has resulted in their dense deployments in diverse environments. While this massive deployment can potentially increase capacity and coverage, the current physical carrier sensing of IEEE 802.11 cannot limit the overall interference induced and also cannot insure high concurrency among transmissions. Recently, the IEEE 802.11 working group has continued efforts on developing WLAN technology through the creation of the TGax, which aims to improve efficiency of densely deployed IEEE 802.11 networks. In this paper, we propose a Dynamic Sensitivity Control for Access Point (DSC-AP) algorithm for IEEE 802.11ax. This algorithm dynamically adjusts the Carrier Sensing Threshold (CST) of an AP based on received signal strength from its associated stations and interfering APs. We show that the aggregate throughput of a dense network (under asymmetric traffic conditions) utilizing DSC (both at the stations and AP) is considerably improved (i.e. up to 32%) when compared with legacy IEEE 802.11. © 2016 IEEE.


Camps-Mur D.,I2CAT Foundation | Garcia-Villegas E.,Polytechnic University of Catalonia | Lopez-Aguilera E.,Polytechnic University of Catalonia | Lambert P.,Marvell Technology Group | Raissinia A.,Qualcomm
IEEE Wireless Communications | Year: 2015

There is untapped potential in the WiFi radios embedded in our smartphone and tablet devices. In this article we introduce the WiFi Neighbor Awareness Networking technology being standardized in the WiFi Alliance®, which leverages this potential by allowing handheld devices to continuously discover other interesting services and devices while operating in the background in an energy-efficient way. In addition, we present a thorough performance evaluation based on packet-level simulations that illustrates the performance of WiFi NAN to be expected in realistic scenarios. © 2002-2012 IEEE.


Torkar R.,Blekinge Institute of Technology | Minoves P.,i2cat Foundation | Garrigos J.,i2cat Foundation
Journal of the Association of Information Systems | Year: 2011

Today's software companies face the challenges of highly distributed development projects and constantly changing requirements. This paper proposes the adoption of relevant Free/Libre/Open Source Software (FLOSS) practices in order to improve software development projects in industry. Many FLOSS projects have proven to be very successful, producing high quality products with steady and frequent releases. This study aims to identify FLOSS practices that can be adapted for the corporate environment. To achieve this goal, a framework to compare FLOSS and industrial development methodologies was created. Three successful FLOSS projects were selected as study targets (the Linux Kernel, the FreeBSD operating system, and the JBoss application server), as well as two projects from Ericsson, a large telecommunications company. Based on an analysis of these projects, FLOSS best practices were tailored to fit industrial development environments. The final results consisted of a set of key adoption opportunities that aimed to improve software quality and overall development productivity by importing best practices from the FLOSS environment. The adoption opportunities were then validated at three large corporations.

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