Itu-t rec. G. 957 (06/99) Optical interfaces for equipments and systems relating to the synchronous digital hierarchy
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Recommendation G.957 (06/99) iii CONTENTS Page 1 Scope........................................................................................................................... 1 2 References................................................................................................................... 1 3 Terms and definitions ................................................................................................. 2 3.1 Definitions .................................................................................................................. 2 3.2 Terms defined in other Recommendations ................................................................. 2 4 Abbreviations.............................................................................................................. 2 5 Classification of optical interfaces.............................................................................. 3 6 Parameter definitions .................................................................................................. 8 6.1 System operating wavelength range............................................................................ 8 6.2 Transmitter.................................................................................................................. 9 6.2.1 Nominal source type ...................................................................................... 9 6.2.2 Spectral characteristics .................................................................................. 9 6.2.3 Mean launched power.................................................................................... 10 6.2.4 Extinction ratio .............................................................................................. 10 6.2.5 Eye pattern mask............................................................................................ 11 6.3 Optical path................................................................................................................. 12 6.3.1 Attenuation .................................................................................................... 12 6.3.2 Dispersion ...................................................................................................... 12 6.3.3 Reflections ..................................................................................................... 12 6.4 Receiver ...................................................................................................................... 13 6.4.1 Receiver sensitivity........................................................................................ 13 6.4.2 Receiver overload .......................................................................................... 13 6.4.3 Receiver reflectance....................................................................................... 14 6.4.4 Optical path power penalty............................................................................ 14 7 Optical parameter values for SDH applications.......................................................... 14 8 Optical engineering approach ..................................................................................... 14 8.1 Design assumptions .................................................................................................... 14 8.2 Worst-case design approach ....................................................................................... 14 8.3 Statistical design approach.......................................................................................... 15 8.4 Upgradability considerations ...................................................................................... 16 8.5 Joint engineering......................................................................................................... 16 Annex A – System operating wavelength considerations ........................................................ 17 A.1 Operating wavelength ranges determined by fibre attenuation................................... 17 A.2 Operating wavelength ranges determined by fibre dispersion .................................... 18 |