COSNET-A Coherent Optical Subscriber Network

Abstract-A complete coherent multi-channel system, designed for application in the local loop is presented. The concept and the technical realization of a uni- and bi-directional system in a laboratory demonstrator are described. The realized network control, including frequency management of the bi-directional channels, and network security are discussed. Attention is paid to the evolution scenario from a narrow band to a complete broad-band system. All aspects are integrated in a demonstrator, which is capable of supporting a large number of narrow-band and broad-band distributive and communicative services. Several novel technical solutions (for frequency management, data in-duced polarization switching (DIPS), high-speed encryption and network signalling) are presented. OHERENT detection has three well known advantages C over direct detection techniques: channel selective de