Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

Publications by Rui Lopes Campos

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.

2014

A ns-3 based simulator of TCP/IP Wireless Underground Networks

Authors
Conceição, S; Ribeiro, F; Campos, R; Ricardo, M;

Publication
IFIP Wireless Days

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. © 2014 IEEE.

2016

BLUECOM plus : Cost-effective Broadband Communications at Remote Ocean Areas

Authors
Campos, R; Oliveira, T; Cruz, N; Matos, A; Almeida, JM;

Publication
OCEANS 2016 - SHANGHAI

Abstract
The ocean and the Blue Economy are increasingly top priorities worldwide. The immense ocean territory in the planet and its huge associated economical potential is envisioned to increase the activity at the ocean in the forthcoming years. The support of these activities, and the convergence to the Internet of Things paradigm, will demand wireless and mobile communications to connect humans and systems at remote ocean areas. Currently, there is no communications solution enabling cost-effective broadband Internet access at remote ocean areas in alternative to expensive, narrowband satellite communications. This paper presents the maritime communications solution being developed in the BLUECOM+ project. The BLUECOM+ solution enables cost-effective broadband Internet access at remote ocean areas using standard wireless access technologies, e.g., GPRS/UMTS/LTE and Wi-Fi. Its novelty lies on the joint use of TV white spaces for long range radio communications, tethered balloons for lifting communications nodes high above the ocean surface, multi-hop relaying techniques for radio range extension, and standard access networks at the ocean. Simulation results prove it is possible to reach radio ranges beyond 100 km and bitrates in excess of 3 Mbit/s using a two-hop land-sea communications chain.

2016

Evaluation of an RPL/6LoWPAN/IEEE 802.15.4g Solution for Smart Metering in an Industrial Environment

Authors
Dias, J; Ribeiro, F; Campos, R; Ricardo, M; Martins, L; Gomes, F; Carrapatoso, A;

Publication
2016 12TH ANNUAL CONFERENCE ON WIRELESS ON-DEMAND NETWORK SYSTEMS AND SERVICES (WONS)

Abstract
This paper describes the evaluation of a multi-hop wireless networking solution for Smart Grid metering in an industrial environment. The solution relies on RPL, 6LoWPAN, and IEEE 802.15.4g protocols, and has been implemented using low-power and low-capacity devices. Also, it supports both TCP and UDP protocols to transport traffic from DLMS/COSEM Smart Grid metering applications. The experimental tests took place in an industrial environment during 20 days. The obtained results allowed the characterization and evaluation of the developed solution and can be used as a basis to evaluate other 6LoWPAN/IEEE 802.15.4g networking solutions.

2015

Evaluation of Underwater IEEE 802.11 Networks at VHF and UHF Frequency Bands using Software Defined Radios

Authors
Teixeira, F; Santos, J; Pessoa, L; Pereira, M; Campos, R; Ricardo, M;

Publication
Proceedings of the 10th International Conference on Underwater Networks & Systems, WUWNET 2015, Arlington, VA, USA, October 22-24, 2015

Abstract
Radio Frequency (RF) communications su.er high attenuation underwater, limiting the range of standard IEEE 802.11 networks to a few centimeters underwater. The usage of custom RF solutions at lower frequencies to increase range entails high development costs, and proprietary hardware. This paper evaluates the performance of cost-e.ective, mass-market IEEE 802.11 networks underwater at di.erent frequencies in the sub-GHz bands using Software Defined Radio platforms. Optimizations to the gr-ieee802.11 implementation, together with custom designed antennas, allowed the testing of frequencies in the 70-700 MHz range, in a large-scale freshwater tank, and in real-world, seawater conditions in Tagus river estuary. Results show a frequency-dependent communications range up to 5 m in freshwater and 1.8 m in seawater, with bitrates up to 550 kbit/s and delay under 45 ms. This proves the feasibility of IEEE 802.11 networks in the sub-GHz bands for applications such as video streaming from an autonomous underwater vehicle and underwater sensors. Copyright 2015 ACM.

2016

Green Wireless Video Sensor Networks using FM Radio System as Control Channel

Authors
Dias, J; Sousa, F; Ribeiro, F; Campos, R; Ricardo, M;

Publication
2016 12TH ANNUAL CONFERENCE ON WIRELESS ON-DEMAND NETWORK SYSTEMS AND SERVICES (WONS)

Abstract
The rise of the Internet of Things and the growth of the IP cameras market are making Wireless Video Sensor Networks (WVSNs) popular. In turn, Wi-Fi is becoming the enabling technology for WVSNs due to its flexibility, high bitrates provided and low cost; however, these networks suffer from three major problems: bad performance, throughput unfairness, and energy inefficiency. In order to address the lack of holistic solutions to solve these problems, we propose the FM-WiFIX+ solution. This solution uses FM radio as an out-of-band control channel to signal when a video sensor should turn its IEEE 802.11 interface OFF, thus saving energy. The results obtained with a proof-of-concept prototype show that for a network with 7 nodes the proposed solution can achieve gains of energy up to 48 %, while maintaining good levels of performance and throughput fairness.

  • 1
  • 11