Energy-Efficient Vector OFDM PLC Systems with Dynamic Peak-Based Threshold Estimation

© 2013 IEEE. Power line communication (PLC) has made remarkable strides to become a key enabler of smart grid and its applications. Existing PLC systems are based on orthogonal frequency division multiplexing (OFDM), which has a high peak-to-average power ratio (PAPR). This paper presents vector OFDM (VOFDM) with advanced signal processing at the receiver to improve the energy efficiency of the PLC system. Results show that, due to its low PAPR properties, VOFDM is less sensitive to impulsive noise and provides a reduction of 5.8 dB in transmit power requirement relative to conventional OFDM. Furthermore, unlike the existing impulsive noise cancellation methods, the adopted signal processing technique also improves the SNR at the receiver by 2.1 dB, which further reduces the power requirement of the PLC transceiver. Together, these can simplify design, reduce cost, and improve energy efficiency of future PLC transceivers

Experimental study of 6LoPLC for home energy management systems

© 2016 by the authors. Ubiquitous connectivity is already transforming residential dwellings into smart homes. As citizens continue to embrace the smart home paradigm, a new generation of low-rate and low-power communication systems is required to leverage the mass market presented by energy management in homes. Although Power Line Communication (PLC) technology has evolved in the last decade, the adaptation of PLC for constrained networks is not fully charted. By adapting some features of IEEE 802.15.4 and IPv6 over Low-power Wireless Personal Area Network (6LoWPAN) into power lines, this paper demonstrates a low-rate, low-power PLC system over the IPv6 network (referred to as 6LoPLC), for Home Energy Management System (HEMS) applications. The overall idea is to provide a framework for assessing various scenarios that cannot be easily investigated with the limited number of evaluation hardware available. In this respect, a network model is developed in NS-3 (Version 21) to measure several important characteristics of the designed system and then validated with experimental results obtained using the Hanadu evaluation kits. Following the good agreement between the two, the NS-3 model is utilised to investigate more complex scenarios and various use-cases, such as the effects of impulsive noise, the number of nodes and packet size on the latency and Bit Error Rate (BER) performances. We further demonstrate that for different network and application configurations, optimal data sizes exist. For instance, the results reveal that in order to guarantee 99% system reliability, the HEMS application data must not exceed 64 bytes. Finally, it is shown that with impulsive noise in a HEMS network comprising 50 appliances, provided the size of the payload does not exceed 64 bytes, monitoring and control applications incur a maximum latency of 238.117 ms and 248.959 ms, respectively; both of which are within acceptable limits

Noise Sources, Effects and Countermeasures in Narrowband Power-Line Communications Networks: A Practical Approach

The integration of Distributed Generation, Electric Vehicles, and storage without compromising the quality of the power delivery requires the deployment of a communications overlay that allows monitoring and controlling low voltage networks in almost real time. Power Line Communications are gaining momentum for this purpose since they present a great trade-off between economic and technical features. However, the power lines also represent a harsh communications medium which presents different problems such as noise, which is indeed affected by Distributed Generation, Electric Vehicles, and storage. This paper provides a comprehensive overview of the types of noise that affects Narrowband Power Line Communications, including normative noises, noises coming from common electronic devices measured in actual operational power distribution networks, and noises coming from photovoltaic inverters and electric vehicle charging spots measured in a controlled environment. The paper also reviews several techniques to mitigate the effects of noise, paying special attention to passive filtering, as for being one of the most widely used solution to avoid this kind of problems in the field. In addition, the paper presents a set of tests carried out to evaluate the impact of some representative noises on Narrowband Power Line Communications network performance, as well as the effectiveness of different passive filter configurations to mitigate such an impact. In addition, the considered sources of noise can also bring value to further improve PLC communications in the new scenarios of the Smart Grid as an input to theoretical models or simulations.This work has been partly funded by the Spanish Ministry of Economy and Competitiveness through the National Program for Research Aimed at the Challenges of Society under the project OSIRIS (RTC-2014-1556-3) and through the network of excellence REDYD2050 (ENE2015-70032-REDT)

Noise Sources, Effects and Countermeasures in Narrowband Power-Line Communications Networks: A Practical Approach

The integration of Distributed Generation, Electric Vehicles, and storage without compromising the quality of the power delivery requires the deployment of a communications overlay that allows monitoring and controlling low voltage networks in almost real time. Power Line Communications are gaining momentum for this purpose since they present a great trade-off between economic and technical features. However, the power lines also represent a harsh communications medium which presents different problems such as noise, which is indeed affected by Distributed Generation, Electric Vehicles, and storage. This paper provides a comprehensive overview of the types of noise that affects Narrowband Power Line Communications, including normative noises, noises coming from common electronic devices measured in actual operational power distribution networks, and noises coming from photovoltaic inverters and electric vehicle charging spots measured in a controlled environment. The paper also reviews several techniques to mitigate the effects of noise, paying special attention to passive filtering, as for being one of the most widely used solution to avoid this kind of problems in the field. In addition, the paper presents a set of tests carried out to evaluate the impact of some representative noises on Narrowband Power Line Communications network performance, as well as the effectiveness of different passive filter configurations to mitigate such an impact. In addition, the considered sources of noise can also bring value to further improve PLC communications in the new scenarios of the Smart Grid as an input to theoretical models or simulations.This work has been partly funded by the Spanish Ministry of Economy and Competitiveness through the National Program for Research Aimed at the Challenges of Society under the project OSIRIS (RTC-2014-1556-3) and through the network of excellence REDYD2050 (ENE2015-70032-REDT)

Cross-layer energy efficiency of plc systems for smart grid applications

Though opinions are still divided over the specific choices of technology for smart grid, there is a consensus that heterogeneous communications network is most appropriate. Power line communication (PLC) is promising because it is readily available and it aligns with the natural topology of power distribution network. One of the emerging realities is that the communication system enabling smart grid must be energy-efficient. This thesis employs a cross-layer approach to address energy efficiency of PLC networks in different smart grid scenarios. At network layer, this work exploits the topology of a PLC-enabled advanced metering infrastructure (AMI) to improve the probability of successful packet delivery across the network. The technique, termed AMI clustering, leverages the traditional structure of the low voltage (LV) network by organising the smart meters into clusters and locally aggregating their readings. Improvement in packet delivery inherently reduces energy wastage. Next, the adaptation layer exploits the low data rate transmission techniques to reduce the energy requirements of PLC nodes. To achieve that, this work developed a network model in NS-3 (an open-source network simulator) that considers PLC transceivers as resource-constrained devices and interconnects them to emulate home energy management system (HEMS). The model was validated with experimental results which showed that in the home area network (HAN), low-rate applications such as energy management can be supported over low-power PLC networks. Furthermore, at physical layer, this thesis proposes a more energy-efficient multi-carrier modulation scheme than the orthogonal frequency division multiplexing (OFDM) used in most of the current PLC systems. OFDM is widely known for its high peak-to-average-power ratio (PAPR) which degrades energy efficiency of the systems. This thesis found that by employing vector- OFDM (V-OFDM), power requirements of PLC transmitter can be reduced. The results also showed the energy efficiency can be further improved by using a dynamic noise cancellation technique such as dynamic peak-based threshold estimation (DPTE) at the receiver. By applying the proposed methods, packet delivery can be improved by 3% at network layer (which conserves energy) and reduced data rate can save about 2.6014 dB in transmit power. Finally, at physical layer, V-OFDM and DPTE can respectively provide 5.8 dB and 2.1 dB reduction in power requirements of the PLC transceivers. These signify that if V-OFDM is combined with DPTE, future PLC modems could benefit from energy-efficient power amplifiers at reduced cost

Alternativas de solución al envenenamiento del Protocolo ARP en entornos LAN

En el presente artículo se presentan algunos fallos de seguridad del protocolo ARP reflejando su vulnerabilidad a diversos tipos de ataques dando lugar a fugas y/o daños de información, se han presentado diversas soluciones factibles en las cuales se encuentran S-ARP (secure ARP), ES-ARP (Secure and efficient ARP) y como alternativa de solución planteamos la creación de algoritmos que permitandetectar y mitigar ataques mediante el uso de Registros Estáticos en la Tabla ARP, como objetivo queremos resolver algunos fallos en la seguridad de ARP cambiando y mejorando los protocolos originales de este realizando las configuraciones que se creen factibles para mejorar su seguridad, en este artículo se realizará un envenenamiento ARP utilizando las herramientas VMware y GNS3 que nos permiten virtualizar un entorno real con el fin de mostrar la inseguridad que posee el protocolo ARP y así mismo implementar una alternativa económica y eficiente que mejore su seguridad