Power Line Communication Networks Research Articles

전력설비 관리를 위한 무선 및 유선 통신 방법에 관한 고찰

Power plants maintenance data is to be sent to management server system via a communication network. In this case, reliable communication network is required. Transmission of the power plants maintenance data is used in the wired communication network or wireless communication network. PLC communication network is a kind of wired communication network. However PLC communication network is easily affected by noise. On the vulnerable areas in power line system, such as a mountain or rural areas, it is difficult to form a power line communication network. For a wireless communication, environment are also influenced factors in wireless communication. Harsh environmental factors are bring the communication characteristic degradation. In such areas it can be used a combination of two networks and in this way the complementary function can be achieved. Power plants are distributed in various regions across the country. The appropriate communication network is needed to maintain the power plant.This study investigated the effect of environment on the wired communication and wireless communication. It would examine a variable factor which is affect to the communication characteristic. We used PLC communication for wired communication network and ZigBee communication for wireless communication network. We investigated the characteristics of a single communication network and it raised the need for a complex communication technology to complement a single communication network.

Optimal Relay Configuration for Power Line Communication Networks

Power line communications networks (PLCNs) facilitate efficient power management, data access, and monitoring services over a home area network by using a network implementation taking advantage of the built-in power cable infrastructure. A control station with which attached user stations communicate over the power line is used to coordinate the communications process. As serious distortion and losses are incurred by signals that are transmitted across the power line, it is highly desirable to employ relay stations to support the transmission of such data flows. Yet, to date, only limited research results are available for the cross-layer synthesis and management of such a relay-aided power line communications system. In this paper, we develop and study a relay backbone synthesis algorithm (RBSA) that is used to configure the PLC network topology, allowing active source stations to efficiently transport their message flows to the control station. We also present a relay backbone synthesis algorithm under fixed-topology (RBSAF) that enables the system management mechanism to jointly activate selective relay stations and schedule their sharing of the PLC medium, when considering nonadjustable PLC network topologies. Our new computationally efficient RBSA and RBSAF schemes are proven numerically to achieve throughput rates close to the optimal solution.

Performance evaluation of in-home broadband PLC systems using a cooperative MAC protocol

In this article, we present an in-depth analysis of cooperation benefits in power line communication (PLC) networks. In order to conduct our evaluation, we present a new, yet simple, cooperative medium access control protocol (CMAC). Our new CMAC protocol uses system nodes as relays adaptively, according to these nodes idleness or busyness. Moreover, the new protocol also explores path diversity offered by an in-home broadband PLC. We have conducted simulations, based on real packet error ratios of in-home networks, using a wide range of configurations. In sum, our results show that cooperation reduces packet loss ratio and improves goodput. For instance, in some scenarios, the protocol we proposed is able to enhance goodput up to 36% and reduce packet loss ratio up to 43% in comparison to a system without cooperative protocols. Moreover, our simulations allow us to delimit the most suitable scenarios to use cooperation. Based on our analyses, we can state the following: (i) improvements increase when frequency bandwidth increases; (ii) irrelevant improvement occurs if total transmission power is too high or too low; (iii) gains offered by cooperation are more relevant depending on relative node relay position in relation to nodes source and destination; (iv) the proposed protocol show improvements regardless of the choice between OFDMA-TDMA and TDMA-OFDM schemes, but improvements are higher when it is used together with the OFDMA-TDMA scheme.

Simulation of low-voltage narrow-band power line communication networks to propagate OpenADR signals

This study analyzes the performance of power-line communications for sending open automated demand response (OpenADR) signals. In particular, we study main channel disturbances that can affect end-to-end communications and which have not been previously studied in detail. Our analysis takes into account physical phenomena, such as background and impulsive noise sources, channel attenuation, and multipath effects, and considers the physical, network, and applications layers of the communications structure. The performance of the physical layer is the basis for computing the packet error rate. In analyzing application performance, we focus specifically on the latency in several communication environments. If a channel is impaired only by background noise, latencies are less than 40 seconds. With the addition of impulsive noise in the channel, this value increases as long as 68 seconds. Using these figures, we find that power-line technology is more suitable for slow demand programs, such as day-ahead or day-of curtailments, rather than ancillary services markets, which require near-real-time communication.

Adaptation of Powerline Communications-Based Smart Metering Deployments to the Requirements of Smart Grids

Powerline communications (PLC)-based smart meter deployments are now a reality in many regions of the world. Although PLC elements are generally incorporated in smart meters and data concentrators, the underlying PLC network allows the integration of other smart grid services directly over it. The remote control capabilities that automation programs need and are today deployed over their medium voltage (MV) grid, can be extended to the low voltage (LV) grid through these existing PLC networks. This paper demonstrates the capabilities of narrowband high data rate (NB HDR) PLC technologies deployed over LV grids for smart metering purposes to support internet protocol internet protocol (IP) communications in the LV grid. The paper demonstrates these possibilities with the presentation of the simulation and laboratory results of IP communications over international telecommunication union: ITU-T G.9904 PLC technology, and the definition of a PLC Network Management System based on a simple network management protocol (SNMP) management information base (MIB) definition and applicable use cases.

Performance analysis for a two-way relaying power line network with analog network coding

In this paper, we investigate a two-way relaying power line communication (PLC) network with analog network coding. We focus on the analysis of the system outage probability, symbol error rate, and average capacity. Specifically, we first derive the probability density function (PDF) of the received signal-to-noise ratio (SNR) with a closed form, by exploiting the statistical properties of the PLC channel. Then with the help of this PDF, we develop the outage probability, symbol error rate, and average capacity with closed forms, based on the Hermite polynomial. Simulations show that the derived analytical results are consistent with those by Monte Carlo simulation.

On efficiency and validity of previous Homeplug MAC performance analysis

The Medium Access Control protocol of Power Line Communication networks (defined in Homeplug and IEEE 1901 standards) has received relatively modest attention from the research community. As a consequence, there is only one analytical model that complies with the standardised MAC procedures and considers unsaturated conditions. We identify two important limitations of the existing analytical model: high computational expense and predicted results just prior to the predicted saturation point do not correspond to long-term network performance. In this work, we present a simplification of the previously defined analytical model of Homeplug MAC able to substantially reduce its complexity and demonstrate that the previous performance results just before predicted saturation correspond to a transitory phase. We determine that the causes of previous misprediction are common analytical assumptions and the potential occurrence of a transitory phase, that we show to be of extremely long duration under certain circumstances. We also provide techniques, both analytical and experimental, to correctly predict long-term behaviour and analyse the effect of specific Homeplug/IEEE 1901 features on the magnitude of misprediction errors. Our simplified analysis is then used to model the priority resolution scheme defined in Homeplug/IEEE 1901. We show that previous tendencies found in simulations and in an off-the-shelf testbed are correctly captured in our framework. We also show that resorting to the traffic differentiation provided by the different contention parameters alone solves the starvation faced by lower-access category traffic.

Distributed space‐time block codes with embedded adaptive AAF/DAF elements and opportunistic listening for multihop power line communication networks

SummaryWe consider the multihop power line communication (PLC) networks of one source, two repeaters, and one destination. In the previous scheme, when the repeaters receive the retransmission data from the source, they use the traditional distributed space‐time block code (DSTBC) with all decode‐and‐forward (DAF) elements to transmit the data, and they do not consider the incorrect decoding. The original contribution is that we propose a novel DSTBC scheme with embedded adaptive DAF/amplify‐and‐forward (AAF) elements for data retransmission in multihop PLC networks with existing opportunistic listening (OL) protocols. The new scheme has two types (instead of only one type as in the previous scheme), and, in the second type, the coding matrix for data retransmission can use either all DAF elements or hybrid AAF/DAF elements depending on the correctness of OL results. The advantage is to avoid a loss of diversity because of incorrectly received data at the relays. The effectiveness of the proposed scheme is shown in the simulation results. For the impulsive noise parameter δ = 0.8 and worst case background noise (narrowband interference and colored noise) at bit error rate 10−3, our proposed system has 1 dB gain over the previous scheme with the traditional DSTBC with all DAF elements. Copyright © 2015 John Wiley & Sons, Ltd.

On multiple‐domain cooperative diversity for communications with distributed content in G.hn networks

SummaryBroadband data applications can be delivered to homes over the available home network infrastructure (i.e., mediums). Further enhancement of the network performance is possible by exploiting spatial, time, or frequency diversity. Recently, MIMO systems have been proposed for power line communication (PLC) networks. Because of the extremely diverse physical characteristics of the mediums, an implementation of MIMO systems in G.hn across different domains represents a non‐trivial task. In this paper, we present and theoretically evaluate the performance of multiple‐domain diversity mechanism in G.hn using a cross‐layer classification algorithm. In the proposed network architecture, the signal is transmitted over different mediums selected by the classification algorithm in order to meet the quality‐of‐service demands. At the receiver, joint signal combining and equalization are done to take advantage of the multiple‐domain cooperative diversity and increase the signal‐to‐noise ratio. The merit of the proposed multiple‐domain PLC network has been confirmed by analytical performance analysis and computer simulation. Copyright © 2015 John Wiley & Sons, Ltd.

A hybrid relay control mechanism for ribbon topology in low‐voltage power line communication networks

SummaryThe communication reliability and distance of the low‐voltage power line communication system are seriously affected by the channel interference and the time variant load impedance. Therefore, how to control the relay nodes to reduce the communication delay and improve the communication reliability is mainly considered in the design. A novel hybrid relay control mechanism (HRCM) that includes the static relay pre‐configuration and the dynamic relay selection is designed for the ribbon topology in the low‐voltage power line communication networks. In the ribbon topology, the initial configuration for the communication link is realized through the pre‐configure relay nodes, which guarantees that the concentrator can communicate with the furthest terminal node. During the normal operations, the dynamic relay node is selected according to the sequence number of the uplink or downlink data frame and the data discard strategy. With the relay node dynamical selected mechanism, the frame repeated transmission can be avoided and the communication delay is reduced. The actual test results show that the hybrid relay control mechanism can effectively extend the communication distance, improve the communication real‐time and the reliability of the low‐voltage power line communication. Copyright © 2014 John Wiley & Sons, Ltd.

The Channel Characteristic and AMR Field Trial Results in China Distribution Grid

Power line communication (PLC) has received much attention recently because of the need of reliable and automatic metering, In this paper we present a comprehensive study over the use of PLC in China. We begin with some background including the distribution grid topology, the power line channel environments, and the deployment of PLC network. Then we show some field test results of PLC-based meter-reading in a high frequency band. In addition, a suggestion how to improve G3-PLC is presented which can adapt China grid better.

Optimal TDMA Scheduling in Tree-Based Power-Line Communication Networks

The large amount of differentiated quality-of-service traffic generated by modern smart grids necessitates efficient scheduling schemes for the uplink traffic. This paper proposes a cross-layer time-division multiple access scheduling scheme destined for broadband power-line communications (BB-PLC)-access networks. The scheme determines the topology of the smart-grid communications (SGC) PLC trees formed across the power grid, identifies the noninterfering segments in the tree graph, and schedules the uplink transmission. The scheme is based on appropriately adjusting the injected power of the SGC tree nodes following a graph-based distributed approach in the attempt to enhance slot reuse. The scheme has been tested and assessed for typical SGC networks deployed in rural and urban areas, considering both aggregated and nonaggregated SGC traffic. The relevant simulations verify that by reducing the interference due to PLC transmission, the proposed adaptive power-control-based scheme can significantly minimize the injected power, enhance throughput, and reduce delay on an SGC cell basis. The reduction in schedule length depends drastically on the maximum-allowed injected power and the topology of the SGC tree and may reach 70% when combined with data aggregation.

DSL and PLC Co-Existence: An Interference Cancellation Approach

It is often advocated that a solution to the problem of interference to digital subscriber line networks (DSL) from a power line communications (PLC) network is to prevent the PLC networks from utilizing the DSL spectrum. However, this solution will render PLC networks inoperable with the introduction of wide-band DSL technology like G.Fast. We propose utilizing an interference cancelling scheme to ensure the co-existence of DSL and PLC networks within the home environment. A measurement campaign is conducted where a set of 480 measurements are collected within a residential house to characterize the PLC-to-DSL interference environment for two DSL modem installation scenarios. The interference cancelling scheme is based on an adaptive frequency domain interference canceller (FDIC) that utilizes the common mode (CM) PLC interference to estimate the differential mode (DM) PLC interference. The effectiveness of the FDIC, which is insensitive to the non-stationarity of the PLC channel, is demonstrated using analysis that incorporates the measured PLC-to-DSL coupling channels.

An MIMO Random Channel Generator for Indoor Power-Line Communication

Multiple-input multiple-output (MIMO) technology has already been used in power-line communication (PLC). An accurate description of MIMO channels for PLC network topologies is of great interest and importance in the development and testing of digital communication algorithms. However, the considerable variability of PLC networks makes this task quite difficult. In this regard, a random channel generator for a single-input single-output (SISO) configuration has been presented in the literature. The procedure was applied to a set of measured channels that were interestingly divided into nine classes. In this paper, an MIMO random channel generator based on the aforementioned SISO configuration is proposed. An MIMO channel is considered as the superposition of correlated SISO channels so we attempt to describe an MIMO channel using the nine classes obtained with the SISO configuration. An additional parameter, related to the correlation factor, had to be taken into account. It is shown that when this parameter is obtained from probabilistic distribution with properly chosen standard deviations for each of the nine classes, the European MIMO PLC field measurements can be accurately reproduced by the random channel generator.

Smart Meter Based on Smart Energy Profile for ZigBee and Power Line Communication Connectivity-Enabled Home Area Network

Home Area Networks can be implemented via both wired and wireless solutions. Smart meter performs power or electricity metering and has the capability of transferring key meter data via wired and wireless sensors. The proposed solution provides a seamless connectivity between ZigBee and Power Line Communication networks to reap benefits from their respective advantages. Since these two technologies are complementary media, the combination is more suitable for smart meter to meet different requirements.

Impedance Characterization of Power Line Communication Networks

AC power lines not only provide electrical energy but can also be used as a communication medium for transmitting data. Besides having numerous advantages, there are certain issues which make the power line channel a hostile environment for communication. One major issue is the unpredictable variation in impedance of the network due to variable loads connected to or disconnected from the system, leading to poor transmission characteristics. These unpredictable variations need to be studied and characterized in order to obtain effective remedy of the problem. For this purpose, simulations were carried out in various scenarios to obtain the statistics/characteristics of impedance, so that useful statistical data are available for modem designers and matching circuit designers in power line communication.

Network Virtualization for Smart Grid Communications

Information exchange is critical in smart grid for system control and management. Optical fibers are widely used in transmission grid and substations to provide high-capacity and high-reliability communications. However, due to high cost and inflexibility, optical fibers are not suitable for information transmission in distribution grid. Wireless mesh network (WMN) and power line communication (PLC) network are more appropriate for distribution grid communications. Nonetheless, both WMN and PLC technologies tend to suffer from bit error and packet loss due to interference and attenuation. It is extremely difficult to provide real-time services with low delay and high reliability in both of them. Network virtualization (NV) is a promising technology to support customized end-to-end performance of various services. In this paper, an NV-based framework is proposed for smart grid communications. In the framework, real-time services are supported by virtual networks (VNs) that are mapped to two physical networks simultaneously, i.e., WMN and PLC network. The WMN for NV is designed to adopt orthogonal frequency division multiple access as the multiple access scheme. In this way, different VNs are allocated distinct subcarriers. Concurrent transmissions in multiple subcarriers bring the benefit of additional diversity. The enhanced transmission diversity through the two networks and the allocated subcarriers contributes to the reliability guarantee of the real-time services. Since the VN mapping and subcarrier assignment problem is nondeterministic polynomial-time hard, a heuristic solution is developed to solve the problem efficiently and effectively. Simulation results reveal the effectiveness of our proposed framework.

Physical layer security in power line communication networks: an emerging scenario, other than wireless

The authors consider the secure transmission of information over power line communication (PLC) networks. The focus is on the secrecy guaranteed at the physical layer, named physical layer security (PLS). Although PLS has been deeply investigated for the wireless case, it is not the same for the PLC environment. Thus, starting from the knowledge in the wireless context, the authors extend the results to typical PLC scenarios. In particular, the PLC channel statistics is evaluated and a performance comparison among PLC and wireless channels is performed, in terms of secrecy rate distribution. For the PLC case, the secrecy rate distribution, under a total power constraint, is evaluated for both optimal and uniform power distributions in broadband channels. To provide experimental evidence, the authors consider channel measures obtained in an in-home measurement campaign. The underlying network presents a tree topology, which introduces frequency and spatial correlation among channels, and suffers from the keyhole effect, generated by branches that depart from the same node. As shown by the numerical results, these effects can reduce the secrecy rate. Finally, the authors evaluate the secrecy rate region for the multi-user broadcast channel considering both simulated channel realisations and experimental channel measures.

Advanced metering infrastructure performance using European low‐voltage power line communication networks

Power line communication has recently attracted the attention of energy companies as a useful and natural technology for building the advanced metering infrastructure. In this context, device language message specification/companion specification for energy metering (DLMS/COSEM) is an increasingly popular standardised application protocol for communication between utilities and their customers. This study analyses the communication performance that can be expected when using the power line communication technology, powerline intelligent metering evolution (PRIME), to send DLMS/COSEM messages. Physical phenomena – such as background and impulsive noise sources, channel attenuation and multi-path effect – are taken into account during the first step in the evaluation of this technology's communication performance in the physical layer. This metric is then used in upper layers to compute the packet error rate. An analysis is carried out at the application layer in terms of expected latency in different communication environments. Several simulations are performed in a European low-voltage topology to compute the number of metres that can be read within 15 min. These simulations were carried out using MATLAB and OMNeT++ software.

Energy efficient network protocol architecture for narrowband power line communication networks

This paper presents newly researched and developed network layer protocol for narrowband power line communication (PLC) within the last mile of advanced metering management systems. This communication medium is known for its low data rates and issues with signal propagation and noise inherence. After the network properties are introduced and some of the published PLC routing papers are discussed, our network layer protocol concept is described with emphasis on the routing algorithm and route optimizations. The protocol is designed to optimize the energy efficiency of the PLC network. The next part of the paper briefly describes the network simulator and its model, which was used during the protocol development and debugging. Several networks with constant and dynamic channel parameters were simulated. The results are presented at the end of the paper. Final results proving energy efficiency and its positive influence on the network performance are presented in comparison to the minimum hop count metric.