2013
Authors
Gouveia, C; Rua, D; Ribeiro, F; Moreira, CL; Pecas Lopes, JAP;
Publication
2013 IEEE GRENOBLE POWERTECH (POWERTECH)
Abstract
The feasibility of the MicroGrid (MG) concept, as the pathway for integrating Electric Vehicles (EV) and other Distributed energy Resources (DER), has been the focus of several research projects around the world. However, developments have been mainly demonstrated through numerical simulation. Regarding effective smart grid deployment, strong effort is required in demonstration activities, addressing the feasibility of innovative control solutions and the need of specific communication requirements. Therefore, the main objective of this paper is to provide an integrated overview of the laboratorial infrastructure under development at INESC Porto, where it will be possible to conceptualize, implement and test the performance of new control and management concepts for Smart Grid cells. The laboratorial infrastructure integrates two experimental MG, including advanced prototypes for power conditioning units to be used in micro generation applications, batteries for energy storage and a fully controlled bidirectional power converter. Preliminary experimental results and organization of the infrastructure are presented.
2013
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.
2017
Authors
Julio, P; Ribeiro, F; Dias, J; Mamede, J; Campos, R;
Publication
2017 WIRELESS DAYS
Abstract
The increasing trend in wireless Internet access has been boosted by IEEE 802.11. However, the application scenarios are still limited by its short radio range. Stub Wireless Multi-hop Networks (WMNs) are a robust, flexible, and cost-effective solution to the problem. Yet, typically, they are formed by single radio mesh nodes and suffer from hidden node, unfairness, and scalability problems. We propose a simple multi-radio, multi-channel WMN solution, named Wi-Fi network Infrastructure eXtension-Dual-Radio (WiFIX-DR), to overcome these problems. WiFIX-DR reuses IEEE 802.11 built-in mechanisms and beacons to form a Stub WMN as a set of self-configurable interconnected Basic Service Sets (BSSs). Experimental results show the improved scalability enabled by the proposed solution when compared to single-radio WMNs. © 2017 IEEE.
2017
Authors
Sousa, F; Dias, J; Ribeiro, F; Campos, R; Ricardo, M;
Publication
2017 Wireless Days, Porto, Portugal, March 29-31, 2017
Abstract
The growth of the IP cameras market, due to their low price and high availability, is making Wireless Video Sensor Networks (WVSNs) attractive. In a mesh, multi-hop video surveillance scenario Wi-Fi is the enabling technology for WVSNs, due to its flexibility and low cost. However, WVSNs still suffer from bad performance, throughput unfairness, and energy inefficiency. Previously, we proposed FM-WiFIX+, a holistic solution to address the problem. FM-WiFIX+ uses FM radio to signal when a video sensor should turn its IEEE 802.11 interface OFF, thus saving energy. Herein, we present a new traffic-aware version of FM-WiFIX+. The results obtained through numerical, simulation, and experimental evaluation demonstrate that the new version can achieve savings in energy consumption up to 84 %, while maintaining the levels of performance and throughput fairness. © 2017 IEEE.
2014
Authors
Conceicao, S; Ribeiro, F; Campos, R; Ricardo, M;
Publication
2014 IFIP Wireless Days (WD)
Abstract
Wireless Underground Networks (WUNs) include communications links between buried nodes and between buried and aboveground nodes. WUNs have many applications, such as border surveillance, agriculture monitoring, and infrastructure monitoring. Recent studies have shown that they are feasible and have deployment advantages over wired networks. Yet, so far WUNs evaluations have been done using testbeds only, and a tool enabling simulations on TCP/IP WUNs is lacking. We propose a simulator of TCP/IP wireless underground networks based on ns-3. The simulator was validated against experimental results for 433 MHz and 2.4 GHz frequency bands. The results show its accuracy for most of the communications scenarios.
2018
Authors
Sousa, F; Dias, J; Ribeiro, F; Campos, R; Ricardo, M;
Publication
IEEE ACCESS
Abstract
The availability of low cost networked wireless devices and video cameras is enabling wireless video sensor networks (WVSNs), which can be used in scenarios such as healthcare, agriculture, smart cities, intelligent transportation systems, and surveillance. These scenarios typically require that each node sends a video stream to a server located in the cloud. The IEEE 802.11 is considered a suitable technology for transmitting video wirelessly, as it supports high data rates. However, when using a multi-hop topology to extend the IEEE 802.11 coverage, the IEEE 802.11-based WVSNs suffer from three problems: low network capacity, throughput unfairness, and energy inefficiency. To overcome these problems, we propose a holistic solution, named Green wiReless vidEo sENsor NEtworks uSing out-of-band Signalling (GREENNESS). GREENNESS combines a node polling mechanism with the use of out-of-band signaling over a low power radio to signal when a video sensor should switch ON and OFF its IEEE 802.11 interface, thus saving energy. The results obtained for random network topologies show that GREENNESS can achieve energy savings up to 92%, and improve network capacity and throughput fairness when compared to state of the art CSMA/CA-based WVSN solutions.
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