Current state of communication systems based on electrical power transmission lines

Antony Ndolo & İsmail Hakkı Çavdar

Journal of Electrical Systems and Information Technology

Abstract

Power line communication technology is a retrofit alternative technology for last mile information technology. Despite several challenges, such as inadequate standards and electromagnetic compatibility, it is maturing. In this review, we have analysed these obstacles and its current application status.

Introduction

Indeed, advancements in communication engineering and technology have brought in revolution in the telecommunication industry. One great impact has been in information and service delivery during the last decades of the twentieth century to date. This is due to the high demand for information created by the huge human population. Better methods and channel models for signal transmission have been researched and developed. For instance, fibre optics has provided waveguide for numerous services at higher speed while inheriting other advantages such immunity to electromagnetic interferences amongst others [1, 2]. Despite all the positive attractions towards fibre communication, it is expensive to install and it is limited to certain areas. That is, remote, rural and mountainous areas. This has necessitated the search for alternative information transmission methods. Power line communication (PLC) is one such alternative.

Power line communication technology is the basically a technology that uses pre-existing and installed electrical power cables for transmission of information [3,4,5,6]. Traditionally, such electrical lines were designed exclusively for distribution and transmission of electricity at lower frequency. This frequency varies from country to country, mainly, 50 Hz or 60 Hz. Upon generation of electricity, it is distributed and transmitted through different voltage network. Firstly, electricity is transmitted over high voltage lines, then distribution is done over medium voltage lines, and lastly, it is converted/scaled down using transformers for the end-user consumption in the low-voltage lines. Figure 1 gives summary of PLC structure. This technology is therefore retrofit and economically cheaper compared to other methods. There is no need for new cable installations. Secondly, electrical power network is the most developed, covers large areas and reaches many homesteads. At distribution lines, they are majorly used for the control signals, remote data acquisition and IP telephony services [7].

Structure of power line communication network

Power line communication is divided into three categories, namely ultra-narrowband, narrowband and broadband as summarised in Table 1. The first two are commonly grouped together and termed as narrowband PLC. We will characterise these categories in the next section in details.

Read more