Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ester López is active.

Publication


Featured researches published by Ester López.


conference on computer communications workshops | 2011

Energy Efficiency in integrated IT and optical network infrastructures: The GEYSERS approach

Anna Tzanakaki; Markos P. Anastasopoulos; Konstantinos Georgakilas; Jens Buysse; Marc De Leenheer; Chris Develder; Shuping Peng; Reza Nejabati; Eduard Escalona; Dimitra Simeonidou; Nicola Ciulli; Giada Landi; Marc Brogle; Alessandro Manfredi; Ester López; Jordi Ferrer Riera; Joan A. Garcia-Espin; Pasquale Donadio; Giorgio Parladori; Javier Jiménez

In this paper we propose energy efficient design and operation of infrastructures incorporating integrated optical network and IT resources. For the first time we quantify significant energy savings of a complete solution jointly optimizing the allocation and provisioning of both network and IT resources. Our approach involves virtualization of the infrastructure resources and it is proposed and developed in the framework of the European project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services.


wireless and mobile computing, networking and communications | 2012

Community-lab: Architecture of a community networking testbed for the future internet

Axel Neumann; Ivan Vilata; Xavier León; Pau Escrich Garcia; Leandro Navarro; Ester López

Community networks are an emerging and successful model for the Future Internet across Europe and far beyond. The CONFINE project complements existing FIRE (Future Internet Research and Experimentation) infrastructures by establishing Community-Lab, a new facility for experimentally-driven research built on the federation of existing community IP networks constituted by more than 20,000 nodes and 20,000 Km of links. In this paper we present the benefits of having such testbed for the research community as well as the improvement and evolution of community networks themselves. This paper presents i) the challenges and requirements for Community-Lab, ii) the resulting testbed architecture, iii) the current state of implementation and iv) the integration of the testbed with existing community networks.


wireless and mobile computing, networking and communications | 2012

An evaluation of BMX6 for community wireless networks

Axel Neumann; Ester López; Leandro Navarro

Nowadays, a growing number of communities of citizens build, operate and own open IP-based community wireless networks with thousands of low capacity nodes actively participating in routing the data traffic. This article focuses on one of their concerns, routing and its scalability, by presenting BatMan-eXperimental Version 6 (BMX6) and evaluating its performance. BMX6 is a low overhead and scalable mesh network routing protocol inspired by human networks. Its performance is evaluated in comparison with OLSR in terms of overhead and convergence time as networks grow in number of nodes and diameter. The results show that the convergence time and protocol overhead per node in BMX6 is not significantly affected by the addition of new nodes in contrast with OLSR, where both parameters can grow super-linearly. This confirms the excellent scalability of BMX6.


Future Internet | 2011

Bringing optical networks to the cloud: an architecture for a sustainable future internet

Pascale Vicat-Blanc; Sergi Figuerola; Xiaomin Chen; Giada Landi; Eduard Escalona; Chris Develder; Anna Tzanakaki; Yuri Demchenko; Joan Antoni Garcia Espin; Jordi Ferrer; Ester López; Sébastien Soudan; Jens Buysse; Admela Jukan; Nicola Ciulli; Marc Brogle; Luuk van Laarhoven; Bartosz Belter; Fabienne Anhalt; Reza Nejabati; Dimitra Simeonidou; Canh Ngo; Cees de Laat; Matteo Biancani; Michael Roth; Pasquale Donadio; Javier Jiménez; Monika Antoniak-Lewandowska; Ashwin Gumaste

Over the years, the Internet has become a central tool for society. The extent of its growth and usage raises critical issues associated with its design principles that need to be addressed before it reaches its limits. Many emerging applications have increasing requirements in terms of bandwidth, QoS and manageability. Moreover, applications such as Cloud computing and 3D-video streaming require optimization and combined provisioning of different infrastructure resources and services that include both network and IT resources. Demands become more and more sporadic and variable, making dynamic provisioning highly needed. As a huge energy consumer, the Internet also needs to be energyconscious. Applications critical for society and business (e.g., health, finance) or for real-time communication demand a highly reliable, robust and secure Internet. Finally, the future Internet needs to support sustainable business models, in order to drive innovation, competition, and research. Combining optical network technology with Cloud technology is key to addressing the future Internet/Cloud challenges. In this context, we propose an integrated approach: realizing the convergence of the IT- and optical-network-provisioning models will help bring revenues to all the actors involved in the value chain. Premium advanced network and IT managed services integrated with the vanilla Internet will ensure a sustainable future Internet/Cloud enabling demanding and ubiquitous applications to coexist.


international conference on transparent optical networks | 2011

Energy efficiency considerations in integrated IT and optical network resilient infrastructures

Anna Tzanakaki; Markos Anastasopoulos; Konstantinos Georgakilas; Jens Buysse; M. De Leenheer; Chris Develder; Shuping Peng; Reza Nejabati; Eduard Escalona; Dimitra Simeonidou; Nicola Ciulli; Giada Landi; Marc Brogle; Alessandro Manfredi; Ester López; J. Ferrer Riera; Joan A. Garcia-Espin; P. Donaldio; Giorgio Parladori; Javier Jiménez; A. Tovar De Duenyas; Pascale Vicat-Blanc; J. van der Ham; C. de Laat; Mattijs Ghijsen; Bartosz Belter; Artur Binczewski; Monika Antoniak-Lewandowska

The European Integrated Project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services - is concentrating on infrastructures incorporating integrated optical network and IT resources in support of the Future Internet with special emphasis on cloud computing. More specifically GEYSERS proposes the concept of Virtual Infrastructures over one or more interconnected Physical Infrastructures comprising both network and IT resources. Taking into consideration the energy consumption levels associated with the ICT today and the expansion of the Internet in size and complexity, that incurring increased energy consumption of both IT and network resources, energy efficient infrastructure design becomes critical. To address this need, in the framework of GEYSERS, we propose energy efficient design of infrastructures incorporating integrated optical network and IT resources, supporting resilient end-to-end services. Our modeling results quantify significant energy savings of the proposed solution by jointly optimizing the allocation of both network and IT resources.


modeling, analysis, and simulation on computer and telecommunication systems | 2014

Cloud-Based Extension for Community-Lab

Mennan Selimi; Jorge L. Florit; Davide Vega; Roc Meseguer; Ester López; Amin M. Khan; Axel Neumann; Felix Freitag; Leandro Navarro; Roger Baig; Pau Escrich; Agusti Moll; Roger Pueyo; Ivan Vilata; Marc Aymerich; Santiago Lamora

Community-Lab is an open, distributed infrastructure for researchers to carry out experiments within wireless community networks. Community networks are an emergent model of infrastructures built with off-the-shelf communication equipment that aims to satisfy a communitys demand for Internet access and ICT services. Community-Lab consists of more than 100 nodes that are integrated in existing community networks, thus giving researchers access to community networks and allowing them to conduct experimental evaluation of routing protocols, services and applications deployed there. Community networks have now the opportunity to extend the collaborative network building to the next level, that is, building collaborative services implemented as community clouds, built, operated and maintained by the community, that run on community-owned heterogeneous resources, and offer cloud-based services that are of the communitys interest. This demo paper focuses on demonstrating the cloud extension of Community-Lab, enabling now community cloud experiments. By means of selected applications, we show how Community-Lab has been extended with distributed clouds, where different devices such as server, desktop PCs, low-resource embedded PCs and IoT boards are brought together forming a heterogeneous distributed cloud environment for researchers to experiment in community networks.


Computer Networks | 2015

Evaluation of mesh routing protocols for wireless community networks

Axel Neumann; Ester López; Leandro Navarro

In recent years, we have witnessed the exponential growth of wireless community networks as a response to the clear necessity of Internet access for participation in society. For wireless mesh networks that can scale up to thousands of nodes, which are owned and managed in a decentralized way, it is imperative for their survival to provide the network with self-management mechanisms that reduce the requirements of human intervention and technological knowledge in the operation of a community network. In this paper, we focus on one important self-management mechanism, routing, and we study the scalability, performance, and stability of three proactive mesh routing protocols: BMX6, OLSR, and Babel. We study different metrics on an emulation framework and on the W-ILab.T testbed at iMinds, making the most of the two worlds. Emulation allows us to have more control over the topology and more systematically repeat the experiments, whereas a testbed provides a realistic wireless medium and more reliable measurements, especially in terms of interference and CPU consumption. Results show the relative merits, costs, and limitations of the three protocols.


ieee international conference on cloud computing technology and science | 2012

A multi-tenancy model based on resource capabilities and Ownership for infrastructure management

Joan A. Garcia-Espin; J. Ferrer Riera; S. Figuerola; Ester López

This paper presents a multi-tenancy model based on infrastructure resource capability virtualisation. The model, namely Resources, Ownership, Roles and Actors or RORA, approaches network and IT infrastructure virtualisation seamlessly, thus enabling complex provisioning workflows for Cloud services and network services attached.


international conference on peer-to-peer computing | 2013

Community home gateways for P2P clouds

Pau Escrich; Roger Baig; Ivan Vilata; Axel Neumann; Marc Aymerich; Ester López; Davide Vega; Roc Meseguer; Felix Freitag; Leandro Navarro

We present the community home gateway, a computer system attached to a wireless community network router, able to host platform and application services. Different to current home gateways and other low-end systems, the community home gateway offers resource virtualization, and can thus be used as a cloud resource. Furthermore, it removes the lack of a home gateway system that is open for service contributions and therefore constitutes an important step towards building P2P clouds with low-end devices.


trust, security and privacy in computing and communications | 2015

KDet: Coordinated Detection of Forwarding Faults in Wireless Community Networks

Ester López; Leandro Navarro

Wireless Community Networks (WCN) are grassroot initiatives that leverage the connectivity gap by providing an alternative ownership model for IP-networks, where every piece of equipment is managed and owned in a decentralized fashion by members from the community. However, 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. Here we present KDet, a distributed 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.

Collaboration


Dive into the Ester López's collaboration.

Top Co-Authors

Avatar

Leandro Navarro

Polytechnic University of Catalonia

View shared research outputs
Top Co-Authors

Avatar

Axel Neumann

Polytechnic University of Catalonia

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge