Analysis and evaluation of in-home networks based on HomePlug-AV power line communications

[ESP] No hace mucho tiempo, las redes in-home (también denominadas redes domésticas) únicamente se utilizaban para interconectar los diferentes ordenadores de una vivienda, de manera que pudieran compartir una impresora entre ellos. Hoy en día, sin embargo, esta definición es mucho más amplia debido a la gran cantidad de dispositivos existentes en la vivienda con capacidad de conectarse a una red para transmitir y recibir información. En una red in-home actual, podemos encontrar desde teléfonos móviles equipados con conectividad WI-FI a dispositivos NAS (Network Attached Storage), utilizados para almacenar información, imágenes o videos en red, que a su vez pueden ser transferidos a televisiones de alta definición u ordenadores. A la hora de instalar una red de comunicaciones en una vivienda, se persiguen principalmente dos objetivos, reducir el coste de instalación y conseguir una gran flexibilidad de cara a futuras ampliaciones. Una red basada en tecnología PLC (Power Line Communications) cumple estos requisitos ya que, al utilizar la infraestructura de cableado eléctrico existente en la vivienda, es muy sencilla y económica de instalar y ampliar. Dentro de la tecnología PLC existen diferentes estándares, siendo HomePlug-AV (HomePlug Audio-Video o simplemente HPAV) el más extendido en la actualidad para la instalación de redes domésticas. Este estándar permite alcanzar velocidades de transmisión de hasta 200Mbps a través de los cables de baja tensión de una vivienda convencional. El objetivo principal de esta tesis doctoral es aportar nuevas ideas que mejoren las prestaciones de las redes in-home basadas en la tecnología PLC, utilizando como base el estándar Homeplug-AV. Estas redes utilizan una arquitectura centralizada, en la que la mayor parte de la inteligencia de red está concentrada en un coordinador central (CCo, por sus siglas en inglés). Por lo tanto, la mayor parte de las modificaciones propuestas irán encaminadas a mejorar dicho dispositivo, que podrá llegar a convertirse en un gestor de red capaz de manejar conjuntamente interfaces de diferentes tecnologías. En primer lugar, se presenta un análisis detallado del comportamiento del estándar en diferentes situaciones que se pueden producir de manera común en una red doméstica. Este análisis se realizó tanto con dispositivos reales como mediante simulación. Para el segundo tipo de medidas, se diseñó un simulador de la tecnología HomePlug que implementa el nivel físico y el nivel MAC de la misma, junto con modelos de los servicios más utilizados en entornos domésticos. Este simulador se utilizó tanto para estas medidas iniciales como para evaluar las diferentes modificaciones del estándar propuestas posteriormente en este trabajo. Este análisis proporcionó dos resultados significativos. En primer lugar, se comprobó que al introducir un modelo real de nivel físico al protocolo CSMA/CA utilizado a nivel MAC se producían resultados muy diferentes a los presentados en los modelos publicados hasta ese momento. Por ello, se propuso un modelo matemático que incorporaba dichos efectos. En segundo lugar, se identificaron diferentes áreas de la tecnología que eran susceptibles de mejora. El resto de la tesis se centró entonces en la mejora de dichos puntos débiles. El primero de estos puntos débiles está relacionado con las transmisión de datos unicast. El medio PLC es selectivo en frecuencia y muy dependiente del tiempo y de la localización de las estaciones. Incluso es posible que, en un mismo enlace, la capacidad de los enlaces ascendente y descendente sea distinta. En estos entornos, la utilización del protocolo de transporte TCP presenta serios problemas, ya que define gran parte de sus parámetros en función del Round Trip time (RTT) del enlace. Como alternativa se pensó en los códigos Fountain. Este tipo de codificación de fuente permite realizar transmisiones fiables de datos sin necesidad de utilizar un canal de retorno, evitando de esta forma los problemas derivados de las asimetrías de la red. Se realizaron varios experimentos comparando ambas soluciones, y se comprobó que las prestaciones de este tipo de codificaciones superan al protocolo TCP a la hora de transmitir ficheros de manera fiable a través de las redes PLC. Además, los códigos Fountain también se utilizaron para el diseño de otra aplicación. Es muy común que en un escenario doméstico haya disponible más de una tecnología (Wi-Fi, Ethernet, PLC, etc). Tenemos por tanto que una aplicación capaz de integrar interfaces de diferentes tecnologías podría ser muy útil en estos entornos, ya que se podría conseguir un mayor ancho de banda, mayor tolerancia a errores, balanceo de carga, etc. El kernel de Linux dispone de un módulo denominado Bonding que permite agrupar diferentes interfaces Ethernet. Sin embargo, no está preparado para agrupar interfaces de diferentes tecnologías, y mucho menos para tecnologás de capacidad variable como es el caso de PLC o de las comunicaciones inalámbricas. Por ello, se realizó una modificación de dicho driver utilizando para ello los códigos Fountain, que solucionan los problemas que se pueden producir debido a las variaciones de capacidad. Por otra parte, con la actual versión del estándar HomePlug AV, las comunicaciones multicast presentan unas prestaciones muy pobres. Esto es debido a que, a pesar de que el canal PLC es broadcast, la naturaleza de la modulación OFDM (Ortogonal Frequency Division Multiplexing) que se utiliza a nivel físico es punto a punto. Esto hace que las transmisiones simultáneas a un grupo de receptores se traduzcan automáticamente en sucesivas transmisiones punto a punto a los diferentes miembros del grupo. Con esta técnica, la capacidad efectiva de transmisión multicast disminuye de manera muy importante a medida que aumenta el número de receptores. En este trabajo se han propuesto dos técnicas alternativas. La primera consiste en la utilización de un mapa de tonos común para todos los miembros del grupo multicast, asignado a estas comunicaciones los parámetros de modulación del cliente con las peores condiciones de canal. Este algoritmo ha sido tradicionalmente descartado en los sistemas OFDM por sus bajas prestaciones. Sin embargo, la correlación existente entre los diferentes canales de una red PLC hace que su comportamiento sea mucho mejor. Además, se propuso un segundo algoritmo que utilizaba técnicas de optimización para maximizar la tasa de comunicación multicast, obteniendo un mejor comportamiento cuando el número de clientes es elevado. Por último, en redes de capacidad física variable, como es el caso de las redes PLC, las técnicas cross-layer están despertando un gran interés. Este tipo de algoritmos están basado en la compartición de información entre diferentes capas de la estructura OSI para mejorar el comportamiento del sistema. En este trabajo se ha propuesto un algoritmo que modifica los parámetros del protocolo CSMA/CA de nivel MAC utilizando información de nivel físico y los requerimientos de QoS del servicio de niveles superiores. De esta forma se consigue dar prioridad en el acceso al medio a los clientes con problemas de QoS, mejorando de esta forma del comportamiento de la red. Este algoritmo ha sido evaluado mediante simulación en un escenario doméstico típico, comprobando que ofrece unos resultados muy prometedores. [ENG] Not very long time ago, in-home networks (also called domestic networks) were only used to share a printer between a number of computers. Nowadays, however, due to the huge amount of devices present at home with communication capabilities, this definition has become much wider. In a current in-home network we can find, from mobile phones with wireless connectivity, or NAS (Network Attached Storage) devices sharing multimedia content with high-definition televisions or computers. When installing a communications network in a home, two objectives are mainly pursued: Reducing cost and high flexibility in supporting future network requirements. A network based on Power Line Communications (PLC) technology is able to fulfill these objectives, since as it uses the low voltage wiring already available at home, it is very easy to install and expand, providing a cost-effective solution for home environments. There are different PLC standards, being HomePlug-AV (HomePlug Audio-Video, or simply HPAV) the most widely used nowadays. This standard is able to achieve transmission rates up to 200 Mpbs through the electrical wiring of a typical home. The main objective of this thesis is to provide new ideas to improve the performance of PLC technology based in-home networks, using as starting point the HPAV standard. A network based on this technology uses a centralized architecture, in which the most important part of the network intelligence is concentrated in a single device, the Central Coordinator (CCo). Hence, most of the modifications proposed in this work will try to improve this particular device, which can even become a multi-technology central manager, able to combine interfaces of different technologies to improve the network performance. Initially, it is presented a detailed analysis of HPAV performance in some scenarios typically found in a home environment. It was done through simulation and by experimentation using real devices. To obtain the former results, it was designed a HPAV simulator which implements the physical (PHY) and medium access control (MAC) layers of the standard, together with a traffic modeling module which implements the services most commonly found in a home network. This simulation tool was used both in these initial measurements and to evaluate the standard modifications that are proposed in this work. This analysis provides two main results. Firstly, it was found that when a real PHY model is used together with the CSMA/CA MAC protocol the simulation results were very different to those obtained with previously presented mathematical models of this protocol. Hence, it was proposed a new model that considers these effects. Next, some areas of the technology which could be improved were identified. The rest of the thesis was then centered around proposing solutions to these weaknesses. The first weakness solved is related to unicast data transmission. PLC medium is frequency selective and time variant, and it presents a remarkable variation among locations or depending on the connected loads. Even in a single link, the channel capacities between transmitter and receiver can be very asymmetric. In such environments, the use of TCP as transport protocol presents serious problems, since it defines some of its parameters according to the Round Trip Time (RTT). Alternatively, the use of Fountain codes for reliable data transmission in these environments was proposed. These codes allow to transmit information without a feedback channel, overcoming in this way the problems related to the variability of the channel. Different experiments were performed comparing both solutions, concluding that in PLC based networks the performance achieved by Fountain codes outperforms the results obtained with a TCP-based application. In addition, Fountain codes were also used for another application. In home environments, it is very common to find more than one available technology to deploy a network (Wi-Fi, Ethernet, PLC, etc). Therefore, an application that makes possible the aggregation of different interfaces would be very useful, as it will provide higher bandwidth, fault tolerance and load balancing. The Linux Kernel contains a driver (Bonding) which allows Ethernet interfaces aggregation. However, it is not prepared for asymmetric interfaces aggregation and even less for variable capacity technologies like PLC or Wi-Fi. In this work, it is presented a modification of this driver which uses Fountain codes to solve the problems that may arise when asymmetric interfaces are aggregated. On another note, multicast communications in the actual HPAV standard versions presents serious problems. This is because, although PLC medium is broadcast by nature, the Orthogonal Frequency Division Multiplexing (OFDM) modulation used at PHY layer is always point to point. Therefore, multicast communications are carried out as successive point-to-point transmissions to the different members of the group. This technique clearly degrades the performance of multicast services as the number of receivers increases. In this work, they have been proposed two alternative algorithms. The first one consists of using a common tone map for all the multicast group members. This tone map corresponds to the modulation parameters obtained for the client with the worst channel conditions. This algorithm has been traditionally discarded in OFDM systems because of its poor performance. However, in contrast to other technologies (like wireless for example), channel responses in a given PLC network exhibit significant correlation among them. This reduces the differences among the users, improving the performance of this algorithm. In addition, another technique which uses an optimization algorithm to maximize the multicast bit rate is also evaluated, obtaining that its use can be suitable when the number of multicast clients is high. Finally, due to the properties of PLC medium, cross-layer technique are eliciting a big interest. These algorithms are based in the information sharing between adjacent layers in the OSI model to improve the system behavior. In this work, it has been proposed an extension of the HPAV CSMA/CA algorithm which modifies the protocol parameters using PHY layer information and the QoS requirements of the upper-layer services. In this way, priority access to the channel can be provided to the nodes with QoS problems, improving the whole network performance. This algorithm has been evaluated through simulation in a typical home environment with very promising results.Universidad Politécnica de Cartagen

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 analytic model that complies with the standardised MAC procedures and considers unsaturated conditions. We identify two important limitations of the existing analytic 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 analytic 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

Analysis of power line communications for last-hop backhaul in small cells deployment

Publicado en: :(2019-04-05),(José A. Cortes, Francisco J. Cañete, Matías Toril, Luis Díez, Alicia García-Mozos, "Analysis of power line communications for last-hop backhaul in small cells deployment", in Proceedings of the IEEE International Symposium on Power Line Communications and its Applications, 2019.),yEditor(IEEE)The purpose of this work is to study the feasibility of using power line communications (PLC) over outdoor public lighting networks (OPLN) for last-hop backhaul in small cell deployment. The analysis is based on actual noise measurements performed in two OPLN in the city of Málaga (Spain) and on a bottom-up channel simulator, which has been designed according to the physical characteristics and the common practices in such kind of networks. Estimations of the bit-rate achieved by PLC systems following the ITU-T Rec. G.9960 (G.hn) standard, are performed and discussed. Results indicate that PLC is a promising solution for this application.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Simulation of Achievable Data Rates of Broadband Power Line Communication for Smart Metering

This paper presents results of such a simulation study. It is based on realistic PLC channel model implementation in Network Simulator 3, our modification and extension of this implementation for our use case scenario. It uses Shannon’s formula to calculate theoretical maximum channel capacity. In particular, it provides channel capacity and achievable distances of broadband PLC (BB-PLC). In this article we also exploit our novel idea of simple performance assessment of broadband PLC communication via simulation. It is supposed to be used to understand, evaluate, and test the grid configuration before deployment

POWER LINE COMMUNICATIONS FOR SMART HOME NETWORKS: MODELING, SIMULATION AND OPTIMIZATION

In recent years, research and development efforts are devoted to the deployment of information and communication technology (ICT) within residential buildings and houses, in order to provide services that will increase the quality of life. Although this trend is originated in the late 60’s as a result of the application of industrial automation to residential buildings and houses, i.e., home automation, nowadays, further services are offered to the final users, i.e., home networking and energy management. In fact, a lot of effort is put on the joint delivery of these services in order to make the home, namely the smart home (SH), an integral part of the future smart grid (SG). The concept of SH can be described as a house equipped with electronic systems and appliances, namely, “smart” appliances, which are able to exchange information by means of a communication network. However, these systems are characterized by a broad variety of communication technologies, standards and protocols, so that they often cannot interconnect, and/or interoperate and in some cases even coexist. In our opinion, coexistence, interconnection and interoperability problems represents the bottleneck to a pervasive deployment of smart appliances and systems within residential buildings and houses. To this respect, the first topic that we consider in this thesis is the definition of the SH network architecture and devices, which allows to obtain convergence among smart appliances. To this aim, a survey of the communication technologies, standards, protocols and also media, which can be used for SH applications, is necessary in order to define a network topology that is able to be scalable, extensible, and rather reliable. Moreover, in order to achieve interconnectivity among “smart” appliances, we define a shared common layer that is able to manage heterogeneous lower layers allowing network convergence. Once defined the SH network architecture and its network devices, we focus on power line communication (PLC) technologies and we implement a network testbed in order to evaluate some of the functionalities of the SH network within real environments. From the analysis of field trial data, we are able to highlight performances and disadvantages of two representative narrow band PLC (NB-PLC) solutions. Furthermore, exploiting the network testbed where broadband PLC (BB-PLC) technology is used to provide an Ethernet backbone for NB-PLC devices, we achieve interconnectivity between heterogeneous devices and we observe a significant improvement of the performances. Although NB-PLC technologies have been conceived for the development of low data rate applications and, in particular, for automatic meter reading (AMR), we focus our attention on the G3-PLC technology, for which we propose enhancements at the medium access control (MAC) sub-layer to allow the implementation of SH applications that could potentially require higher data rate than AMR. The G3-PLC technology has been taken into account since (i) it has been used as baseline technology for the development of popular communication standards for SG applications, and (ii) we have found, from the field trials, that the performance of NB-PLC may be poor in large houses where the signal is strongly attenuated because it spans large distances and crosses different circuit breakers (CBs), e.g., in multi-floor houses. Furthermore, an innovative cross-platform simulator that allows to realistically simulate the G3-PLC technology up to the network layer is presented. The proposed cross-platform consists of two different simulators jointly connected: one for the physical (PHY) layer and one for the data link layer (DLL)/network layer (NL). The PHY layer simulator is implemented in MATLAB, while the DLL/network simulator in OMNeT++. A convergent network architecture that permits the integration of the G3-PLC technology within a switched Ethernet network is also presented with the aim of improving the G3-PLC performance in large scale houses/buildings. The performance of the considered communication technology are presented through extensive numerical results for the in-home application scenario. Finally, the cross-platform simulator is used to evaluate G3-PLC systems for SG applications in the access network scenario. This is fundamental since the interaction of the outside world, i.e., the access network, with the SH is mandatory in order to achieve and exploit the SG concept. Moreover, to improve the performance and coverage of G3-PLC, a simple adaptive tone mapping algorithm together with a routing algorithm are also presented.Ricerca condotta all'interno del WiPLi Lab/Wireless and Power Line Communications LaboratoryopenDottorato di ricerca in Ingegneria industriale e dell'informazioneopenDI BERT, Luc

Transmission haut-débit sur les réseaux d'énergie: principes physiques et compatibilité électromagnétique

Power Line Communications consist of transmitting data by reusing the existing powerline as a propagation medium. Powerline networks represent a challenging environment for broadband communications, since they have not been designed for the transmission of high frequency signals. This Habilitation degree thesis presents our research on transmission physics and electromagnetic compatibility for in-home powerline networks. This research has been conducted since 2007 in the framework of a collaboration between Orange Labs and Telecom Bretagne, involving my supervision of three Ph.D. theses defended in 2012, 2013 and 2015, as the principal advisor.La technologie Courant Porteur en Ligne consiste à transmettre des données en réutilisant le réseau électrique classique en tant que support de propagation. Les réseaux d'énergie sont des environnements difficiles pour les communications à haut débit, car ils n'ont pas été conçus pour la transmission d'un signal à haute fréquence. Ce mémoire d'Habilitation à Diriger des Recherches présente mes travaux concernant la physique de la transmission et les aspects de Compatibilité Electro-Magnétique (CEM) pour le réseau électrique domestique. Ils ont été réalisés à partir de 2007 dans le cadre d'une collaboration entre Orange Labs et Telecom Bretagne, notamment à travers trois thèses soutenues en 2012, 2013 et 2015. Après une introduction générale à la technologie CPL, le manuscrit décrit l'environnement de propagation dans les réseaux d'énergie en termes de canal et de bruit électromagnétique. Les principes de la modélisation du canal CPL sont illustrés à partir de la problématique d'identification des trajets de propagation. L'une des principales évolutions du domaine concerne l'application de la technologie Multiple Input Multiple Output (MIMO) aux communications sur réseaux d'énergie. Nos études expérimentales ont démontré que l'adaptation de cette technique issue du domaine de la radio permet un doublement de la capacité de transmission. Nous présentons les campagnes de mesure réalisées au sein d'Orange Labs et du groupe Specialist Task Force 410 de l'ETSI. A partir de ces données, des modèles statistiques de canal de propagation MIMO et de bruit multi-capteurs ont été élaborés. En termes d'émission électromagnétique, la bande utilisée par les systèmes CPL est déjà occupée par d'autres services (radio amateur, radiodiffusion en ondes courtes). Nous décrivons les contraintes CEM des systèmes CPL et abordons les techniques de CEM cognitive, consistant à optimiser les ressources spectrales en tenant compte de la connaissance de l'environnement du système. En particulier, la technique de retournement temporel est étudiée pour la mitigation du rayonnement involontaire et sa performance est étudiée de manière expérimentale. Enfin, le manuscrit présente la problématique de l'efficacité énergétique des systèmes CPL. Nous présentons les mesures expérimentales réalisées afin de modéliser la consommation de modems classiques et MIMO. D'autre part, la configuration de communication en relais a été étudiée, afin d'évaluer le gain de ce mode de transmission en termes de consommation énergétique. A l'avenir, ces travaux pourront être étendus aux réseaux de distribution en basse et moyenne tension, pour le développement et l'optimisation des réseaux d'énergie intelligents, ou Smart Grids

Caractérisation et modélisation du canal et du bruit pour les réseaux CPL MIMO domestiques

Power Line Communication (PLC) technology provides the omnipresence of high speed data services without requiring the installation of new infrastructure. The existing household electrical wiring which is used to deliver the electrical energy to the house is utilized by the PLC technology as a transmission channel. The data rates of several hundreds of Mbps are realized by the PLC technology. In most developed countries the cable used for household electrical wiring consists of three wires: Phase (P), Neutral (N) and Protective Earth (PE). The existing PLC systems use the P-N port to transmit and receive the signals. It is a typical single input single output (SISO) transmission. The inclusion of the PE wire at transmit and receive outlets leads to the availability of multiple transmit/receive ports which in turn leads to the realization of a MIMO communication channel. The principle objective of this thesis is to study and explore the inhome PLC channels in the MIMO context. The main objectives of the thesis are categorized as the following: ¿ Development of a channel sounding protocol to perform extensive channel and noise measurements on the inhome PLC networks, with the objective of generating a rich and realistic database. Evaluation of the MIMO PLC channel capacity by utilizing the database obtained from the measurements. ¿ Characterization and modeling of the inhome MIMO PLC channel through a set of parameter by utilizing the measured channel data. Evaluation of the performance of the channel model by comparing the simulated channels parameters with the measured ones. ¿ Characterization and modeling of the MIMO power line noise through various parameters by utilizing the measured noise data. Evaluation of the performance of the noise model by comparing the simulated noise characteristics with the measured noise.La technologie Courants Porteurs en Ligne (CPL) répond aux besoins de couverture des services à haut débit sans nécessiter l'installation de nouvelle infrastructure. Dans la plupart des pays développés, le câble utilisé pour construire le réseau domestique d'énergie est constitué de trois fils : le fil de Phase (P), le fil de Neutre (N) et le fil de Terre (en anglais, Protective Earth, PE). Les systèmes CPL actuels utilisent les fils P et N (que l'on notera port P-N) pour émettre et recevoir des signaux de manière différentielle. Typiquement, il s'agit d'un mode transmission utilisant un capteur à l'émission et un capteur à la réception, ce que l'on nomme généralement transmission Single Input Single Output (SISO). Dans le domaine de la communication sans fil, les techniques Multiple Input Multiple Output (MIMO) sont largement employées pour augmenter la capacité du canal. Elles consistent à utiliser plusieurs antennes à l'émission et plusieurs antennes à la réception et bénéficier ainsi de la diversité du canal. Dans le contexte CPL, la présence du fil PE dans les prises électriques de transmission et de réception permet d'envisager la possibilité d'utiliser plusieurs ports d'émission et de réception, ce qui constitue un canal de communication MIMO. Des mesures et des simulations réalisées pour les canaux de transmission CPL ont montré une nette augmentation de la capacité du canal en utilisant les techniques MIMO par rapport aux systèmes traditionnels SISO. L'objectif principal de cette thèse est l'étude et l'exploration des canaux CPL domestiques dans le contexte MIMO. Il s'agit d'une étude détaillée des technologies CPL existantes et d'une investigation des caractéristiques des canaux CPL MIMO. Les objectifs principaux de la thèse sont : Le développement d'un protocole de sondage afin de réaliser des mesures intensives du canal de transmission et du bruit électromagnétique sur les réseaux CPL domestiques. L'objectif est de générer une base de données riche et réaliste. La base de données obtenue par les mesures permettra d'évaluer la capacité du canal CPL MIMO. La caractérisation et la modélisation du canal de transmission CPL MIMO domestique via un ensemble de paramètres, en utilisant les mesures de canal obtenues par la campagne de mesure. La performance du modèle de canal sera évaluée par la comparaison entre les canaux simulés et les canaux mesurés. La caractérisation et la modélisation du bruit électromagnétique CPL MIMO via plusieurs paramètres, en utilisant les mesures de bruit obtenues par la campagne de mesure. La performance du modèle de bruit sera évaluée par la comparaison entre le bruit simulé et le bruit mesuré

Reliable indoor power line communication systems: via application of advanced relaying processing

In this thesis, we focus on improving the performance of indoor power line communication (PLC) systems using relaying schemes. A method of modelling relay-involved PLC channels has been proposed. We study the optimal joint transceiver and relay power allocation problem for relay-assisted multicarrier indoor PLC systems. We transform the nonconvex problem into a group of sub-problems which can be efficiently solved using standard convex optimization techniques. The proposed schemes outperform conventional direct PLC systems

Empirical model that allows evaluating the performance of the LAN based on the Homeplug AV standard for the transmission of voice over the IP protocol

La presente tesis de investigación plantea el desarrollo de un modelo experimental para evaluar el rendimiento de una red LAN operando con el estándar Homeplug AV y para la transmisión de VoIP. Para el desarrollo del modelo empírico se plantearon escenarios de prueba considerando el uso de 1,2,5 y 10 estaciones en una red LAN intercambiando paquetes de información tipo VoIP. En las pruebas se utilizó el software generador de tráfico Distributed Internet Traffic Generator (D-ITG) versión 2.61 y se emplearon adaptadores Homeplug marca TP-LINK modelo TL-PA211. Se generó tráfico tipo aleatorio para los codecs de audio más representativos (G711, G723.1, G729) y se registraron datos de los siguientes parámetros de rendimiento: throughput, jitter, retardo y porcentaje de paquetes perdidos. La investigación realizada permitió obtener un modelo estadístico de evaluación del comportamiento de la red eléctrica para la transmisión digital de información de voz (tráfico VoIP), teniendo en cuenta la cantidad de equipos (A) y los codecs usados (B) en una red LAN, operando bajo el estándar Homeplug AV. Dentro de las conclusiones obtenidas a partir de la presente investigación se destaca que con respecto al parámetro pérdida de paquetes, en la totalidad de las mediciones realizadas se obtuvo un valor igual a cero (0). Con relación al Throughput, se encontró que los factores códec utilizado y número de estaciones en la red, así como su interacción, tienen un efecto estadísticamente significativo para un porcentaje equivalente al 95% de confianza. El análisis de varianza para el Jitter estableció que los factores códec (A) y número de estaciones (B) en la red tienen efectos individuales estadísticamente significativos y los efectos de la interacción AB no influyen estadísticamente en el modelo planteado. Para el Retardo se encontró que únicamente el número de estaciones (B) tiene un efecto estadísticamente significativo.INTRODUCCIÓN 12 2. MARCO REFERENCIAL 17 2.1 TRANSMISIÓN DE INFORMACIÓN EN REDES ELÉCTRICAS 17 2.1.1 Tecnologías PLC 17 2.1.2 Fundamentos de operación de la tecnología PLC 19 2.2 TECNOLOGÍA PLC BAJO EL ESTÁNDAR HOMEPLUG AV 21 2.2.1 Evolución y normalización del estándar Homeplug 22 2.2.2 Prestaciones del estándar Homeplug AV 23 2.3 ELEMENTOS RELEVANTES A LAS TECNOLOGIAS PLC – HOMEPLUG AV 25 2.3.1 Modulación OFDM 25 2.3.2 Ruido en redes LAN PLC 26 2.3.3 Calidad del Servicio 27 2.3.3.1 Clasificación de paquetes 28 2.3.3.2 Manejo de Prioridad 28 2.4 ARQUITECTURA DE LA RED LAN BAJO EL ESTÁNDAR HOMEPLUG AV 30 2.4.1 Niveles de Protocolos 30 2.4.2 Arquitectura de Red 32 2.4.3 Limitaciones técnicas de la red PLC bajo el estándar Homeplug AV 34 2.4.3.1 Propagación de la señal Homeplug AV 34 2.4.3.2 Interferencia en redes PLC 35 2.5 TECNOLOGÍA VOIP EN REDES LAN PLC 36 2.5.1 Voz sobre protocolo IP 37 2.5.2 Codificación de la Voz 39 2.5.3 Ancho de banda para Voz en IP 41 2.5.4 Calidad de Voz en redes IP 43 2.5.4.1 Retardos 43 2.5.4.2 Pérdida de paquetes 44 2.5.4.3 Jitter 44 2.5.4.4 Eco 44 2.5.4.5 Tamaño de paquetes 45 3. MÉTODO 46 3.1 DISEÑO EXPERIMENTAL 46 3.2 PLANEACIÓN DEL EXPERIMENTO 48 3.2.1 Rendimiento 48 3.2.1.1 Throughput 48 3.2.2.2 Jitter 49 3.2.2.3 Retardo 49 3.2.2.4 Pérdida de paquetes 50 3.2.2 Dispositivos y especificaciones 50 3.2.3 Generador de Tráfico 52 3.2.4 Consideraciones adicionales 54 3.2.5 Tamaño de la muestra 54 3.3 DESCRIPCIÓN DEL EXPERIMENTO 56 3.4 DATOS REUNIDOS A PARTIR DE LA EXPERIMENTACIÓN 59 4. RESULTADOS 63 4.1 ANÁLISIS DE RESULTADOS 63 4.2 MODELO ESTADÍSTICO Y ANÁLISIS DE VARIANZA PARA THROUGHPUT 64 4.3 EVALUACIÓN DE LOS RESULTADOS OBTENIDOS A PARTIR DE LA EXPERIMENTACIÓN 68 4.3.1 Supuesto de Varianza Constante 68 4.3.2 Supuesto de Normalidad 69 4.3.3 Supuesto de Independencia 70 4.4 MODELO ESTADÍSTICO Y ANÁLISIS DE VARIANZA PARA JITTER 71 4.5 MODELO ESTADÍSTICO Y ANÁLISIS DE VARIANZA PARA RETARDO 76 5. CONCLUSIONES Y RECOMENDACIONES 82 5.1 CONCLUSIONES 82 5.2 RECOMENDACIONES 84 REFERENCIAS 87MaestríaThis research thesis proposes the development of an experimental model to evaluate the performance of a LAN network operating with the Homeplug AV standard and for VoIP transmission. For the development of the empirical model, test scenarios were considered considering the use of 1,2,5 and 10 stations in a LAN network exchanging VoIP-type information packets. In the tests, the Distributed Internet Traffic Generator (D-ITG) version 2.61 traffic generator software was used and TP-LINK brand TL-PA211 model Homeplug adapters were used. Random type traffic was generated for the most representative audio codecs (G711, G723.1, G729) and data on the following performance parameters were recorded: throughput, jitter, delay and percentage of packets lost. The research carried out allowed obtaining a statistical model for evaluating the behavior of the electrical network for the digital transmission of voice information (VoIP traffic), taking into account the number of equipment (A) and the codecs used (B) in a LAN network. , operating under the Homeplug AV standard. Within the conclusions obtained from the present investigation, it is highlighted that with respect to the packet loss parameter, in all the measurements carried out, a value equal to zero (0) was obtained. Regarding Throughput, it was found that the codec factors used and the number of stations in the network, as well as their interaction, have a statistically significant effect for a percentage equivalent to 95% confidence. The analysis of variance for the Jitter established that the codec factors (A) and the number of stations (B) in the network have statistically significant individual effects and the effects of the AB interaction do not statistically influence the proposed model. For the Delay, it was found that only the number of stations (B) has a statistically significant effect.Rendimento é um dos aspectos mais interessantes da análise global nas redes LAN, devido ao efeito produzido sobre o utente final. A definição de rendimento pode ser abordado a partir de diferentes pontos de vista, o que lhe permite incorporar outras formas de avaliação, segundo o objeto de interesse em particular. Basicamente, os parâmetros mais comuns para avaliar o rendimento em uma rede são: throughput, utilização do canal e diversas medidas de retardo. Neste artigo apresenta-se análise experimental sobre o comportamento do throughput em redes LAN sobre power line communications (PLC), sob uso de adaptadores de rede suportados com o estándar HomePlug 1.0