Final Report on a Study to Investigate PLT Radiation

Final Report on a Study to Investigate PLT Radiation (Summary)

R V Womersley.
R D Simmons.
C V Tournadre.

1 Introduction

1.1 General

1.1.1 This document has been prepared by The Smith Group Limited (Smith) for the Radiocommunications Agency (RA) and represents the final deliverable on project AY 3062 concerning a study to develop a model to predict the radiation properties of certain line transmission systems.

1.2 Project background

1.2.1 The aim of the project was to develop a model to predict the radiation characteristics of certain wide bandwidth line transmission systems, in particular:

Power Line Transmission (PLT) – a system being used by Nor.Web in the North West of the UK which uses the mains electricity system as a means for data transfer;

Digital Subscriber Loop (xDSL) – a system proposed by British Telecom which uses the existing twisted pair distribution network as a means for data transfer.

1.2.2 The model was designed to meet certain objectives, namely:

it should predict the maximum and likely variability of both E and H fields produced in a variety of locations around the system under consideration;

the model should work for frequencies from 300 kHz to 3 GHz. (For generality, the model developed actually spans the range of frequencies from 30 kHz to 3 GHz, and allows a bandwidth in the range from 0.1kHz to 1000kHz to be individually specified for both the transmitted signal and the receiver response);

the launch power, frequency and impedance should be adjustable.

1.2.3 The potential for any interference from these systems to other radio systems should also be determined.

1.2.4 The model produced by the project, ADAPPT (Advanced DSL And PLT Prediction Tool), meets all these criteria and further it allows for the simple inputting of a number of different scenarios and the setting of the key parameters that affect the radiation properties of the system such as the size of houses, the number of floors in a block of flats, the width of streets and pavements, the impedance of the electricity meter, and so on.

1.2.5 Our recommendations as to the level of interference which should be produced by such systems are detailed and it is clear from this that the levels produced by the real-life systems (and as supported by ADAPPT) are very significantly above these levels.

20 November 1998