Fiber networks maintenance in the all-optical network era

This paper deals with topics related to optical network maintenance, highlighting new approaches to optical network monitoring to be applied in a scenario dominated by the growth of photon-based transmission solutions. Special emphasis is given to network solutions based on dense wavelength division multiplexing (DWDM) and optical fiber amplifier (OFA), analyzing the possible in-service signal degradation introduced by traditional, OTDR-based surveillance methodology, as well as the advantages of innovative continuous monitoring technologies and their service level agreement (SLA) management capability. Service level management (SLM) is described and discussed in a typical dark fiber leasing situation. Recent ITU-T Study Group activities related to optical network maintenance issues are also discussed.