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 Wednesday, June 01, 2005
ITU-T's Study Group 15 has agreed on design guidelines for optical fibre submarine cable systems.

Submarine cable systems form a very important part of the world's ICT network infrastructure with cables linking all the world's continents except Antarctica. And as demand for increased transmission capacity increases, owners of these networks are keen to optimize their investments, because laying new submarine cables is an expensive and difficult business.

The guidelines appear in a supplement to ITU-T Recommendations on the topic of submarine cable systems (Supplement 41, to the G series of ITU-T Recommendations), and allow for the incorporation of traditional technology (e.g. WDM systems, erbium doped fibre amplifiers) as well as new technology including new generation forward error correction (FEC) and Raman amplifiers.

According to the expert authors, the document has been produced with a key objective to detail the main technical issues to be taken into account in order to achieve a link's longest distance, with maximum reliability.

The supplement describes considerations for repeatered, repeaterless and optically amplified systems supporting synchronous digital hierarchy (SDH) and optical transport network (OTN) signals. Repeaterless submarine cable systems are used for terrestrial network extensions in cases where submarine distances up to about 350 km are to be covered. Repeatered submarine systems are used for long haul, large capacity transmission by using submerged optical amplifiers in order to cross distances up to transoceanic lengths.