Power Line Telecommunication Research Articles

The emission characteristics and interference analysis of Power Line Telecommunication

This paper describes characteristics of PLT emission with experiment in semi-anechoic chamber and suggests the method for aggregating multiple interferences based on probabilistic approach in the situation in which multiple PLT modems are operating in close proximity to the radio receiver. The levels of the conducted and radiated emission and the APD characteristics are presented. And compatibility between PLT and radio receiver is analyzed with suggested method. This will be useful for assessing interference effect in the field of radio communication and electromagnetic compatibility.

A Design Method for the Asymmetric Artificial Network With an Asymmetrical Transformer

Conducted asymmetric disturbances are measured at telecommunication ports of equipment under test using an asymmetric artificial network (AAN). Therefore, theoretical investigations are carried out to characterize an AAN with a mode-impedance matrix, introducing the common-mode and differential-mode impedances. By referring to this matrix, a theoretical design method is developed for the AAN with an asymmetrical transformer to satisfy the requirements for the mode impedances and the longitudinal conversion loss. By using this design method, two different prototype AANs are assembled: one meets the CISPR 22 specifications, and the other is used in power line telecommunication modem tests. A detailed experimental examination of the assembled AANs validates the proposed theoretical design method.

30 MHz 이하에서 무선 서비스와 유도성 시스템 간의 보호 거리 산출

본 논문은 30 MHz 이하에서 동작하는 유도성 시스템과 전파통신 서비스의 공존을 위해서, 유도성 시스템의 간섭으로부터 전파통신 서비스를 보호하기 위한 보호 거리에 관한 것이다. 보호 거리 산출을 위해 유도성 시스템과 전파통신 서비스 간의 간섭 시나리오 모델을 제시하고 이를 기반으로 유도성 시스템의 방사 전력과 희생원의 허용 가능한 전계 강도를 비교하여 적용된 전파 모델에 따른 보호 거리를 산출하는 방법을 제안하였으며 이 방법을 적용한 RFID(Radio Frequency IDentification), PDP(Plasma Display Panel) TV의 간섭 분석을 통해, 30 MHz 이하의 전파통신 서비스 보호를 위한 보호 거리를 도출하였다. 제안한 방법은 2012년 6월 SG(Study Group) 1 회의에서 ISM 기기에 대한 결의 63과 관련된 ITU-R 권고서로 채택되어 유도성 시스템뿐만 아니라 무선전력 전송 및 전력선 통신 등에 의한 간섭 영향 분석에 활용될 전망이다. This paper describes separation distance to protect radiocommunication services from the interference of inductive systems using frequencies below 30 MHz for the co-existence between radiocommunication services and inductive systems. For the analysis, the interference scenario model is proposed between inductive system and radiocommunication services. Then the calculation method of protection distance is suggested by comparing the radiation power of inductive system with the allowable interference level of victim services, radiocommunication services, according to the applied propagation model. Also, the protection distance for protecting radiocommunication services in the 30 MHz below is calculated through the interference analysis from RFID(Radio Frequency IDentification) and PDP(Plasma Display Panel) TV based on the suggested method. The proposed calculation method was adopted as ITU-R recommendation in related with resolution 63 at ITU-R SG(Study Group) 1 meeting in June, 2012. It will be available to use for the protection of radiocommunication services from the interference of wireless power transfer system and power line telecommunication system.

Field Measurements of EM Radiation From In-House Power Line Telecommunications (PLT) Devices

This paper presents the results of the tests performed by the Communications Research Centre Canada (CRC) to determine the levels of electromagnetic radiation resulting from the operation of commercially available in-house power line telecommunication (PLT) devices, and to evaluate their potential effects on FM radio and low-VHF TV broadcasting services. The tests were performed when the devices were operating under real conditions in a number of typical Canadian suburban residential houses. The corresponding field strength measurements were made at specific distances from the houses and could then be compared with the present regulatory limits.

A measurement-driven approach to assess power line telecommunication (PLT) network quality of service (QoS) performance parameters

Power line telecommunication (PLT) technology offers cheap and fast ways for providing in-home broadband services and local area networking. Its main advantage is due to the possibility of using the pre-existing electrical grid as a communication channel. Nevertheless, technical challenges arise from the difficulty of operating on a hostile medium, not designed for communication purposes, characterized by complex channel modeling and by varying time response. These aspects put practical problems for designers and testers in the assessment of network quality of service performance parameters such as the throughput, the latency, the jitter, and the reliability. The measurement of these parameters has not yet been standardized so that there do not exist reference test set-ups and measurement methodologies (i.e. the type of isolation from the ac main, the observation time and the number of experiments, the measurement uncertainty and so on). Consequently, experiments executed by adopting different methods may lead to incompatible measurement results, thus making it also impossible to have reliable comparisons of different PLT modems. Really, the development of standard procedures is a very difficult task because the scenarios in which the PLT modems can work are very wide and then the application of an exhaustive approach (in which all the parameters influencing the PLT performance should be considered) would be very complex and time consuming, thus making the modem characterization very expensive. In this paper, the authors propose a methodological approach to develop an efficient measurement procedure able to reliably assess the performance of PLT modems (in terms of network quality of service parameters) with a minimum number of experiments. It is based on both creating a reconfigurable grid to which real disturbing loads are connected and implementing an original design of the experiment technique based on the effects of the uncertainty of the measurement results. Methods are also provided to analyze measurement results and to estimate the measurement uncertainty.

The theoretical foundations for calculating the technical parameters for low-tension overhead electricity lines for use in telecommunications

This article presents the properties of electric power networks for use as a channel for transmitting telecommunications signals. It starts by exploring the principles and theoretical basis for calculating power lines' critical technical parameters, referring in detail to the following primary parameters: inductance, capacitance, conductance and resistance. It then deals with e secondary parameters (most useful from a telecommunications perspective): characteristic impedance and propagation constant (the attenuation constant being the latter's real component). Different topologies and low- and medium-tension aerial power line structures are verified; a mathematical model is then proposed to analyse their behaviour at high frequencies, extending to most aerial electric power distribution systems in Colombia. This work includes some of the results from previous research which was known as "Using power line telecommunications (PLT) technology for designing a solution for accessing the broadband internet in rural areas of Colombia" by the present author and the Pilot University of Colombia. The proposed mathematical model provides a tool for making theoretical calculations applicable to PLT.

Potential effects of broadband wireline telecommunications on the HF spectrum

Power line telecommunications and various forms of digital subscriber line transmissions are recent and rapidly evolving technologies using the existing electricity power or telephone lines for data transmission at rates higher than 1 Mb/s. As these lines were not designed for transmission of high data rates, they produce noiselike interferences in the HF range. The intensity depends on the electrical characteristics of the lines (balance, match, screening) as well as on the density and area coverage of these new systems. Exact calculations are impossible at this time because of missing models for the new wirebound communication systems with respect to emission of radio noise in the HF band. Early measurements and estimations showed that radio noise from PLT and xDSL has the potential to cause problems for military HF radio communications and communication intelligence. A Research Task Group under NATO was assigned to study the issue and determine possible solutions. Briefly, the findings of the RTG do indicate that PLT emissions have the potential to cause appreciable degradation in the exploitation of the HF spectrum by military users.

Modelling the cumulative emission field of unstructured telecommunication transmission networks

A detailed and comprehensive methodology for the assessment of the cumulative effect of electromagnetic emissions resulting from the deployment of unstructured telecommunication transmission networks (UTTN) is introduced. Example calculations for various deployment scenarios using digital subscriber line technologies (xDSL) and power-line telecommunication (PLT) are given, thereby providing the means to examine potential implications for present and future radio-based services.

Electromagnetic analysis of horizontal wire in two-layered soil

Simulation of grounding systems at high frequencies is of interest in electromagnetic compatibility, especially related to lightning, and in emerging technologies, such as power line telecommunications. This paper presents first results in the effort to extend the electromagnetic field theory based modeling of grounding systems to a two-layer model of earth. A rigorous mathematical model which solution involves numerical solution of Sommerfeld-type integrals is described. Also new more approximate but computationally more efficient solution based on quasi-static image theory is introduced. Comparison between these two solutions led to conclusion related to the applicability of the image theory approach, which may be of interest for practical problems.

Technological challenges of powerline telecommunication

The basic principles of electric power distribution are reviewed. The technological issues that need to be conquered to utilize powerlines for two-way telecommunication are summarized. The conclusion is that there are many formidable technological obstacles to the practical use of powerlines for telecommunication. ELECTRIC POWER DISTRIBUTION The basic concepts employed in electric power distribution are well over 100 years old and are mostly the visions of Thomas Alva Edison and Nikola Tesla. Edison contributed the basic concepts of end-to-end service, including generation, distribution, metering, switches, and highresistance light bulbs. Tesla contributed the alternating current motor which then made alternating current practical. Electric power is generated by a variety of sources, including steam produced from the combustion of oil and coal or from nuclear energy, water turning turbines, and wind turning generators. An early major innovation in the distribution of electric power was the use of alternating current (ac). The earlier direct current (dc) required ever larger diameters of copper wire to keep the power losses acceptable. These losses occur when electricity flows through the resistance in the distribution wires causing them to heat up and are proportional to product of the resistance of the wire and the square of the current: I2R in equation form. Since all the currents going to the various users of electric power add, the total current soared. The early practical solution was many local power generating plants. This situation changed dramatically with alternating current. The electric transformer (invented by Lucian Gaulard and Josiah Willard Gibbs and first built by William Stanley in 1885) works only with alternating current and allows ac voltages to be transformed from one value to another. But as voltages change, the currents correspondingly change in the opposite direction to keep the electric power into the transformer the same as the output power. Thus by using higher voltages, the currents could be reduced thereby keeping the I2R losses under control in the distribution system. Homes in the United States are served by three power wires. One wire is a common ground. Each of the other two wires has a nominal voltage of 120 volts with respect to ground. Every few homes are served by a step-down power transformer which reduces the input voltage of the few

Power Line Telecommunication

Power Line Telecommunication

Technological challenges of powerline telecommunication

Technological challenges of powerline telecommunication