Introduction to PLCC

INTRODUCTION :-

While the idea of sending communication signals on the same pair of wires as are used for power distribution is as old as the telegraph itself, the number of communication devices installed on dedicated wiring far exceeds the number installed on AC mains wiring. The reason for this is not, as one might think, the result of having overlooked the possibility of AC mains communication until recent decades. In the 1920's, at least two patents were issued to the American Telephone and Telegraph Company in the field of “Carrier Transmission Over Power Circuits”. It has been suggested that this is what was needed in order to overcome the harsh and unpredictable characteristics of the power line environment. Commercial spread spectrum power line telephony has been the focus of research and product development at a number of companies since the early 1980’s. After nearly two decades of development, spread spectrum technology has still not delivered on its promise to provide the products required for the proliferation of power line telephony. This report, after reviewing basic power line telephony characteristics, examines the advantages and disadvantages of power line telephony technology. While earlier thoughts that a new technology was needed to overcome communications challenges were correct, it is the intent of this report to demonstrate the pros & cons of power line telephony and its future scope.