Powerline communications and applications

The powerline channel}electrical power distribution wiring found for example inside buildings, on the power grid, and in vehicles}has long been recognized as a very harsh environment for communication signals. Although there has been some success over the years in transmitting low-speed data over these powerline channels, only recently has there been the convergence of all the technological innovations to overcome the many obstacles to high-speed powerline communication (PLC). A great deal of research and development has been done in recent years on applying innovative communication schemes from the domain of wireless and traditional wire-line channels to the powerline channel. For example, multicarrier modulation schemes such as OFDM used in broadband DSL systems or spread spectrum communications common in wireless communications may now be applied with significant effect to powerline channels. In addition to in-building PLCs over lowvoltage wiring, medium and high-voltage transmission lines are also now being seriously considered for data communications and Internet access, with similar challenges to be overcome. Indeed, the ever-present electrical wiring that traditionally provided only electrical power now also has the potential to be a high-speed information bus, with applications in automobiles, trucks, airplanes, and numerous other situations. Today, PLC can be considered a mature technology. Beside investigation of the ‘last-dirtymile’ problem, new interest has arisen because of recent developments in in-home networking. Generally, technology has improved and has reached the industrial maturity required to become one of the new commonly available alternatives for broadband access and in-home networking. Extremely dense modulation schemes allow co-existence of services on the same line, and with low prices yield excellent business cases for operators, while leaving enough spectrum for consumer appliances. Leading power utilities in Europe and particularly in Germany are successfully operating and expanding their commercial activities by providing PLC services. Currently, there are many sites in the world with thousands of paying customers connected, without disturbing security or any other broadcasting services. Essentially, what is missing is a clear regulatory framework. In several countries regulatory authorities intend to set new radiation limits for PLC systems. There are a number of detailed surveys that review the application of mains signalling systems, focusing on remote meter reading and narrowband customer service applications. However, today these applications seem to be very conservative, and most research has focused on transmission via powerlines using frequencies above 1 MHz: Further, since there is no designated frequency band available for PLC, it is important to protect other systems from PLC emissions. The purpose of this Special Issue is to collect representative research in the general area of low-voltage and medium-voltage PLCs (PLC channel characterization, measurements and