Bart Van Caenegem

Study on the Implementation of Optical Transparent Transport Networks in the European Environment—Results of the Research Project COST 239

This paper reports the main results obtained in the framework of the COST239 project on the implementation of transparent optical network schemes to connect main European cities. The investigation on transmission limitations has shown that transmission systems, for which 1662:5 Gbit/s WDM systems are used due to traf®c reasons, have a maximum range shorter than 1000 km. This condition does not allow a completely transparent network. Two solutions, the partitioned and the gridconnected network architecture, are proposed, described, and compared in the paper.

Restoration and Spare Capacity Assignment in WDM Networks

WDM technology is an emerging technology to enhance the capacity of the existing fiber plant. The throughput is in the order of tens or hundreds of Gbit/s, even in the order of Tbit/s [1,2]. This urges on finding adequate and cost effective means to survive failures in the network. In this paper restoration techniques in WDM networks are discussed and their spare capacity requirement is compared.