RICERCA ITALIANA     

Design and experimentation of naval PowerLine Communications

Università di Pisa

Abstract

The objective of this project is the development and experimental test of an innovative system for naval powerline communications (PLC). It will be investigated the reliability and efficiency of the transmission of command and control data of electrical equipment on ships and pleasure craft, exploiting the powerline cable normally used for the transmission of electric energy instead of a specially dedicated cable system. In such a way, the number of the cables on board ship will be drastically reduced, saving both space and the designing costs of the wiring and electrical installations. This solution is an advanced innovative technique with respect to the currently used solutions on board ships where many dedicated cables are necessary to remotely control the electronic and electromechanical devices that are constantly increasing on board of modern ships.
The project is characterized by strong complementary activities that need synergical expertise apported by the five Research Units (UR). Working in strict cooperation they will be able to develop the research activities by achieving intermediate and final objectives of the project. The project activities will be divided into seven Working Groups (WG), each of them leaded by a URR (identified on the basis of their skills characteristic) that will be responsible of the development of specific tasks of the WG and of the objectives to be achieved according to an appropriate time schedule, articulated in order to achieve >>>

Principal Investigator

Marco Raugi Università degli Studi di PISA

Research Objectives

In order to study and design a naval PLC system we have evidenced six main factors:
1- The definition of a suitable channel model to effectively represent the signal transmission in naval powerlines
2- Knowledge and classification of noise in the channel;
3- Power losses limitation in the coupling between transmitter/receiver and the channel;
4- knowledge of the variations of the channel during the transmission of data;
5- electromagnetic compatibility of the system;
6– Optimization of signal power to transmit the data.

The topic 1 has been introduced to obtain the best possible solution for the actual problems listed in the other 5 topics.

For each of the above described topic the project has specific targets

Topic 1
- Definition of measurable parameters that allow the channel characterization in a wide frequency range and in a number of operating conditions in a nautical environment. The parameter will be inserted in a theoretical model for the numerical simulation of the channel.
- To define procedures and techniques to measure the previously defined parameters
- To define a typical channel model for the numerical simulation of powerline communications
- Implement a channel model for its inclusion in a software simulator of naval powerline communications. This simulator will be used by the project working groups for their activities

Topic 2 >>>

First Results

As previously stated, in this project OFDM modulated signals will be considered. This technique is widely accepted as the most robust for signal transmission in frequency selective and time variant channels (see the Proceedings of IEEE ISPLC Conferences available on IEEEXplore or text books as K. Dostert "Powerline Communications" Springer-Verlag). Indeeed, powerlines behave as a tranmission channel very similarly to the wireless transmission channel. Then, the consolidated results obtained for that applications can ba adopted als o in the PLC environment.

Then, the efficiency of data transmission is mainly determined by five specific factors related to the components of the system:
1. the optimization of bit-loading algorithms;
2. limiting of power losses due to the coupling of transmitters and receivers with the channel;
3- knowledge and classification of noise in the channel;
4- knowledge of the variations of the channel during the transmission of data;
5- electromagnetic compatibility of the system.

To set up an innovative transmission system such as the one here proposed in a naval environment seven Working Groups (WG), each of them managed by a leader Research Unit URR (identified on the basis of its skill characteristics) have been organised. That way the above listed topics have been associated to different WPs with specific aims and targets.
WG 1 Channel Modelling

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Timescale

24 months

National and international background

The transmission of signals to control the electronic and electromechanical devices using powerlines has been exploited since many years by the electric energy supplier companies. For example, the italian company ENEL has been one of the first companies in Europe that have installed a new type of active electrical meters that, using the PLC (Power Line Communication) techniques, are able to provide innovative energy services in anticipation of the liberalization of the electricity supply market.
In recent years, throughout the world there have been large investments of private companies in the production of modems capable of providing broadband signals, by using powerlines in buildings both for private and public use. Many marketed devices are capable to reach average transmission speed of about 30 Mbit/sec in residential low voltage electrical installations. Consequently, the number of companies that are able to provide broadband services both in high populated neighborhoods of cities and in countries located in rural areas, are constantly increasing.
Beyond the significant potential of this technology, some scepticism about the possibility of further increase of the present transmission speeds still exists. These problems concern the increasing demand for "Band" and the real commercial value of the PLC compared with other available technologies (xDSL, Wi-Max, etc.. etc.). Among the technical issues (still under study) that may affect these >>>