Recommendation ITU-T G.959.1 (2024) Optical transport network physical layer interfaces Amendment 1 (08/2024) Updated definition of OTSi Summary History FOREWORD Table of Contents 1 Scope 2 References 3 Terms and definitions 3.1 Terms defined elsewhere 3.2 Terms defined in this Recommendation 4 Abbreviations and acronyms 5 Conventions 6 Classification of optical interfaces 6.1 Applications 6.2 Reference points 6.3 Nomenclature 6.4 Multichannel inter-domain interfaces 6.5 Single-channel inter-domain interfaces 6.6 Management signal implementations 7 Transverse compatibility 8 Parameter definitions 8.1 System operating wavelength range 8.2 Parameters 8.2.1 General information 8.2.1.1 Maximum number of channels 8.2.1.2 Bit rate/line coding of optical tributary signals 8.2.1.3 Maximum bit error ratio 8.2.1.4 Fibre type 8.2.2 Interface at point MPI-SM or MPI-S 8.2.2.1 Maximum and minimum mean (channel) output power 8.2.2.2 Maximum mean total output power 8.2.2.3 Central frequency 8.2.2.4 Channel spacing 8.2.2.5 Maximum spectral excursion 8.2.2.6 Operating wavelength range 8.2.2.7 Source type 8.2.2.8 Maximum and minimum duty cycle 8.2.2.9 Maximum RMS width 8.2.2.10 Maximum (20 dB width 8.2.2.11 Maximum spectral power density 8.2.2.12 Minimum side mode suppression ratio 8.2.2.13 Maximum and minimum (channel) extinction ratio 8.2.2.14 Eye mask for NRZ optical transmit signals 8.2.2.15 Eye mask for RZ optical transmit signals 8.2.2.16 Maximum and minimum channel output OMAouter 8.2.2.17 Maximum TDECQ 8.2.2.18 Minimum channel OMAouter minus TDECQ 8.2.2.19 Maximum TECQ 8.2.3 Optical path (single span) from point MPI-SM to MPI-RM or MPI-S to MPI-R 8.2.3.1 Maximum attenuation 8.2.3.2 Minimum attenuation 8.2.3.3 Maximum chromatic dispersion at the upper and lower wavelength limit 8.2.3.4 Maximum chromatic dispersion deviation 8.2.3.5 Minimum optical return loss at MPI-SM or MPI-S 8.2.3.6 Maximum discrete reflectance between MPI-SM and MPI-RM, or MPI-S and MPI-R 8.2.3.7 Maximum differential group delay 8.2.4 Interface at point MPI-RM or MPI-R 8.2.4.1 Maximum mean (channel) input power 8.2.4.2 Minimum mean channel input power 8.2.4.3 Maximum mean total input power 8.2.4.4 Maximum channel power difference 8.2.4.5 Maximum optical path penalty 8.2.4.6 Minimum equivalent sensitivity 8.2.4.7 Maximum reflectance of optical network element 8.2.4.8 Minimum sensitivity 8.2.4.9 Maximum and minimum channel input OMAouter 8.2.4.10 Maximum multi-path interference penalty allowance 8.2.4.11 Minimum equivalent sensitivity (OMAouter minus SECQ) 9 Parameter values 9.1 Multichannel IrDI 9.2 Single-channel IrDI 10 Optical safety considerations 11 Power level management Annex A Configuration for method A for assessment of single-channel characteristics in a multichannel IrDI A.1 Reference configuration Annex B Reference optical bandpass filter and reference receiver characteristics for method B, for assessment of single-channel characteristics in a multichannel IrDI B.1 Reference configuration B.2 Reference optical bandpass filter B.2.1 Optical filter parameters B.3 Reference receiver Appendix I Single-channel client interfaces with 3R regeneration I.1 Introduction I.2 Description of client signal interfaces with 3R regeneration Appendix II Generic reference points within the OTN Appendix III Clarification of use of reference points within IrDI and IaDI Appendix IV Considerations for management signal implementations IV.1 Optical tributary signal management signal implementation IV.2 Optical multiplex section and optical transmission section management signal implementation Appendix V Nomenclature for the highest class of optical tributary signal supported Appendix VI Optical tributary signal class RZ 40G applications Appendix VII Applications using electronic dispersion compensation Bibliography