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Publications

Publications by José Ruela

2016

A Methodology for the Evaluation and Deployment of Wireless Multi-hop Networks in Smart Grids

Authors
Rua, D; Ribeiro, F; Campos, R; Ruela, J; Pecas Lopes, JAP;

Publication
2016 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC)

Abstract
Smart grids aim at ensuring a secure, reliable and efficient operation of power systems and for that purpose they need communications infrastructures capable of meeting different requirements. Current and emerging wireless multi-hop solutions based on standard technologies are strong candidates for communications networks associated and integrated with electric distribution grids but a suitable methodology to evaluate and deploy them is missing. This paper presents a holistic methodology supported by contextual information used to generate different scenarios of distribution grids and to evaluate and deploy wireless communications networks for smart grids. Simulation results show that the methodology is suitable for the evaluation of wireless multi-hop networks in the smart grid context and prove that the performance of such networks meets the expected requirements of different applications.

2013

PACE: Simple Multi-hop Scheduling for Single-radio 802.11-based Stub Wireless Mesh Networks

Authors
Ribeiro, F; Campos, R; Rua, D; Pinho, C; Ruela, J;

Publication
2013 IEEE 9TH INTERNATIONAL CONFERENCE ON WIRELESS AND MOBILE COMPUTING, NETWORKING AND COMMUNICATIONS (WIMOB)

Abstract
IEEE 802.11-based Stub Wireless Mesh Networks (WMNs) are a cost-effective and flexible solution to extend wired network infrastructures. Yet, they suffer from two major problems: inefficiency and unfairness. A number of approaches have been proposed to tackle these problems, but they are too restrictive, highly complex, or require time synchronization and modifications to the IEEE 802.11 MAC. PACE is a simple multi-hop scheduling mechanism for Stub WMNs overlaid on the IEEE 802.11 MAC that jointly addresses the inefficiency and unfairness problems. It limits transmissions to a single mesh node at each time and ensures that each node has the opportunity to transmit a packet in each network-wide transmission round. Simulation results demonstrate that PACE can achieve optimal network capacity utilization and greatly outperforms state of the art CSMA/CA-based solutions as far as goodput, delay, and fairness are concerned.

2016

Tethered Balloons and TV White Spaces: A Solution for Real-time Marine Data Transfer at Remote Ocean Areas

Authors
Teixeira, FB; Oliveira, T; Lopes, M; Ruela, J; Campos, R; Ricardo, M;

Publication
2016 IEEE THIRD UNDERWATER COMMUNICATIONS AND NETWORKING CONFERENCE (UCOMMS)

Abstract
Autonomous Underwater Vehicles and Remotely Operated Vehicles are useful in industries such as offshore Oil and Gas, deep sea mining, and aquaculture, where inspection missions are frequent. While underwater communications are mainly done using acoustic links, retrieving data from these devices to shore is still an open issue, especially when we consider the high cost of satellite communications. In this paper, using ns-3 simulations, we evaluate the ability of the communications solution being developed in the BLUECOM+ project to enable real-time marine data transfer at remote ocean areas. Through the usage of tethered balloons, TV white spaces frequencies, and multi-hop communications, the BLUECOM+ solution enables cost-effective, broadband connectivity to the Internet at remote ocean areas, using standard access technologies such as GPRS/UMTS/LTE and Wi-Fi. Simulation results show an expected range exceeding 100 km from shore using only two nodes at sea, with bitrates over 1 Mbit/s.

2015

UNIT: Multicast using Unicast Trees

Authors
Teixeira, F; Coutinho, N; Figueira, D; Campos, R; Sargento, S; Ruela, J;

Publication
2015 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATION WORKSHOP

Abstract
The proliferation of broadband wireless accesses has enabled the provisioning of multimedia communication services. Yet, the increasing demand for group-based multimedia services requires the development of new architectures capable of seamlessly delivering multi-party content and overcoming the prevailing heterogeneity and dynamics of current and next generation communication networks. In order to face these challenges we introduce UNIT, a solution that integrates multicast technologies for both core and access wireless mesh networks. UNIT is focused on the scalability and flexibility of the content delivery framework, adopting a hierarchical control strategy that enables seamless multi-party content transport over heterogeneous networks. Moreover, UNIT performs local reconfigurations of the content distribution tree in response to any context change, without impairing the remaining branches. The evaluation of UNIT in a real world demonstrator proves its feasibility and the efficiency of the proposed mechanisms regarding the control of the multi-party delivery trees.

2014

Communications uncertainties in isolated multi-microgrid control systems

Authors
Rua, D; Pecas Lopes, JAP; Ruela, J;

Publication
Proceedings - 2014 Power Systems Computation Conference, PSCC 2014

Abstract
Microgrids have been explored as active cells capable of providing enhanced control schemes towards a more secure, reliable and efficient operation of LV distribution networks or MV networks when aggregated in a multi-microgrid. These structures, within the smart grid concept, rely on a communications infrastructure that introduces uncertainty in the data exchange process. In this paper such uncertainty is evaluated considering a multi-microgrid operating in isolated mode. © 2014 Power Systems Computation Conference.

2002

Support of IP QoS over UMTS Networks

Authors
Manuel Pereira Ricardo; Gustavo João Alves Marques Carneiro; Jaime Sousa Dias; José Ruela

Publication
Proceedings of PIMRC 2002 - 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Lisboa, Portugal

Abstract

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