Pan-European multiwavelength optical network-a systems perspective

The drive towards multiwavelength applications is motivated by a number of commercial and economic factors. However, as yet in Europe, there is little practical experience with installing and operating dense WDM systems. This paper brings practical experience to bear on multiwavelength networks providing an elegant method to expand capacity on existing fibres. For new operators the utilisation of multiwavelength technology also provides a means of future-proofing the network. The network must be seamlessly controlled and managed from end-to-end. This paper discusses the challenges posed to such an operator in terms of design and implementation of a multiwavelength optical network. Considerations such as flexibility, scalability, network management and network resilience are discussed. The WDM feature set encompassing narrow linewidth lasers, filters, and broadband fibre amplifiers are examined and the merits and limitations of each technology are evaluated. In light of this analysis, a very new, leading edge pan-European multiwavelength network built using Nortel technology for one of the new market entrants is discussed. Due to geographical constraints link margins beyond standard multiwavelength capabilities were required. Utilising advanced fibre types and multiwavelength fibre amplifiers, a 2.5G DWDM system has been deployed over a distance of 210 km without the need for any underwater electronics or amplification. This paper presents the system which was deployed and the future upgrade strategies proposed.