Channel characteristic comparison of armored shipboard cable and unarmored one

Power-line communication (PLC) based local area networks (LAN) in ships are one of the promising applications of the PLC technology. There are two types of ships from the viewpoint of the cable structure. One is all the power- line cables are armored, and another type is partly unarmored cables are used. For example, all the cables in cargo ships whose characteristics we measured at last year, were armored, although the cables in a training ship shown in this paper are unarmored partly. In this paper, the channel characteristic which the cable structure affects has been discussed by comparing the two types of ships. It has been concluded that if the unarmored cable is used in a ship, the common-mode transmission will be more useful than the conventional differential-mode transmission, although the countermeasure against unintentional radiation will be needed at the same time. If all the cables are armored in a ship, the radiation problem will not occur, although a kind of adaptive transmission-mode selection technique will be needed to improve the channel capacity of the conventional differential- mode transmission system.