Rec. ITU-T G.989.2 (02/2019) - 40-Gigabit-capable passive optical networks 2 (NG PON2): Physical media dependent (PMD) layer specification
Summary
History
FOREWORD
Table of Contents
1 Scope
2 References
3 Definitions
4 Abbreviations and acronyms
5 Conventions
6 Architecture of the optical access network
     6.1 Physical grouping of logical functions
     6.2 ODN optical path loss (OPL) classes
     6.3 Fibre distance classes
7 Services
8 User network interface and service node interface
9 Common optical network requirements
     9.1 Layered structure of optical network
     9.2 Wavelength plans for NG-PON2
     9.3 Physical media dependent layer requirements
          9.3.1 Physical media and transmission method
               9.3.1.1 Transmission medium
               9.3.1.2 Transmission direction
               9.3.1.3 Transmission method
          9.3.2 Minimum extinction ratio
          9.3.3 Maximum reflectance of equipment, measured at the transmitter wavelength
          9.3.4 Tolerance to reflected optical power
          9.3.5 Optical path between S/R and R/S
               9.3.5.1 Attenuation range
               9.3.5.2 Minimum optical return loss
               9.3.5.3 Maximum discrete reflectance between points S and R
               9.3.5.4 Dispersion
          9.3.6 Receiver at reference point R
               9.3.6.1 Receiver sensitivity
               9.3.6.2 Receiver overload
               9.3.6.3 Maximum optical path penalty
               9.3.6.4 Maximum reflectance measured at the receiver wavelength
               9.3.6.5 Clock extraction capability
               9.3.6.6 Consecutive identical digit immunity
               9.3.6.7 Transmission quality and error performance
          9.3.7 Tunable characteristics for transmitter and receiver
          9.3.8 Minimum side mode suppression ratio
          9.3.9 Out-of-channel power spectral density mask
10 Crosstalk-to-signal ratio tolerance for NG-PON2
     10.1 Wideband X/S tolerance mask definition
          10.1.1 Wideband ONU X/S tolerance
          10.1.2 Wideband OLT X/S tolerance
     10.2 Narrowband TWDM PON X/S tolerance mask
          10.2.1 Narrowband ONU X/S tolerance mask
          10.2.2 Narrowband OLT X/S tolerance mask
11 TWDM PON PMD layer requirements
     11.1 PMD layer requirements
          11.1.1 Nominal Line rate and clock accuracy
               11.1.1.1 Downstream clock accuracy
               11.1.1.2 Upstream clock accuracy
          11.1.2 Line code
               11.1.2.1 Downstream
               11.1.2.2 Upstream
               11.1.2.3 Electronic dispersion compensation
          11.1.3 Operating wavelength
          11.1.4 PMD parameters
               11.1.4.1 Compatible optical distribution network
               11.1.4.2 Optical interface parameters of downstream direction
               11.1.4.3 Optical interface parameters of upstream direction
                    11.1.4.3.1 Example of upstream OPP and receiver substitution
                    11.1.4.3.2 Extinction ratio and minimum mean launch optical power trade off
          11.1.5 Transmitter at reference point S
               11.1.5.1 Source type
               11.1.5.2 Spectral characteristics
                    11.1.5.2.1 Operating wavelength band
                    11.1.5.2.2 Nominal central frequency
                    11.1.5.2.3 Operating channel spacing
                    11.1.5.2.4 Maximum spectral excursion
                    11.1.5.2.5 Minimum tuning window
                    11.1.5.2.6 Tuning granularity
                    11.1.5.2.7 ONU transmitter power wavelength dependency
                    11.1.5.2.8 Mean launch optical power
                    11.1.5.2.9 Upstream optical PSD when not enabled (WNE-PSD)
               11.1.5.3 Mask of transmitter eye diagram
                    11.1.5.3.1 OLT transmitter
                    11.1.5.3.2 ONU transmitter
                         11.1.5.3.2.1 ONU transmitter eye diagram
               11.1.5.4 Jitter performance
                    11.1.5.4.1 Jitter transfer
                    11.1.5.4.2 Jitter tolerance
                    11.1.5.4.3 Jitter generation
     11.2 Upstream physical layer overhead
Annex A  Tunable PtP WDM PON PMD layer requirements
     A.1 PMD layer requirements
          A.1.1 Line rate
          A.1.2 FEC code selection
          A.1.3 Line code
          A.1.4 Operating wavelength
          A.1.5 PMD parameters
               A.1.5.1 Compatible ODN
               A.1.5.2 Optical interface parameters for line rate class 1
               A.1.5.3 Optical interface parameters for line rate class 2
               A.1.5.4 Optical interface parameters for line rate class 3
          A.1.6 Transmitter at reference point S
               A.1.6.1 Nominal central frequency
               A.1.6.2 Mask of transmitter eye diagram
               A.1.6.3 Jitter performance
Annex B  Auxiliary management and control channel
     B.1 Introduction
     B.2 Transparent AMCC
          B.2.1 Baseband overmodulation
          B.2.2 RF-pilot-tone
Annex C  Low loss (LL) PtP WDM PON PMD layer requirements
     C.1 PMD layer requirements
          C.1.1 ODN optical path loss classes
          C.1.2 Fibre distance classes
          C.1.3 Line rate
          C.1.4 FEC code selection
          C.1.5 Line code
          C.1.6 Operating wavelength
          C.1.7 PMD parameters
               C.1.7.1 Optical interface parameters for line rate class 1
               C.1.7.2 Optical interface parameters for line rate class 2
               C.1.7.3 Optical interface parameters for line rate class 3
          C.1.8 Transmitter at reference point S
               C.1.8.1 Nominal central frequency
               C.1.8.2 Mask of transmitter eye diagram
               C.1.8.3 Jitter performance
Annex D   ONU power levelling
     D.1 Interaction between NG-PON2 PMD layer and TC layer
     D.2 Power levelling (PL) mechanism at ONU transmitter
     D.3 ONU autonomous power levelling
     D.4 OOC and OOB PSD relaxation
     D.5 OLT directed ONU power levelling
     D.6 ONU troubleshooting considerations
Appendix I  Wavelength considerations for NG-PON2, XG-PON1, G-PON and RF video overlay distribution services
Appendix II  Physical layer measurements required to support optical layer supervision
Appendix III  Allocation of the physical layer overhead time
Appendix IV  Jitter budget specifications for TWDM PON
Appendix V  Measurement of TWDM PON burst mode acquisition time and burst node eye opening at OLT
Appendix VI   Nonlinear Raman interactions in optical fibres and mitigation technologies for coexistence of multiple PONs
Appendix VII  Cyclic AWG channel grid design examples
Appendix VIII  Wavelength multiplexer, upstream inter-channel crosstalk, ONU transmitter tuning time considerations and upstream channel grid example
     VIII.1 Wavelength multiplexer
     VIII.2 Upstream inter-channel crosstalk
          VIII.2.1 Worst-case design approach
          VIII.2.2 Statistical design approach
          VIII.2.3 Method to limit the inter-channel crosstalk impairment
     VIII.3 ONU transmitter tuning time
     VIII.4 TWDM PON upstream channel grid examples
     VIII.5 Detail of OOC near the channel band edge
Appendix IX  Alternative line code for Raman mitigation
     IX.1 8B10B scheme
          IX.1.1 Power spectral density of 8B10B code
          IX.1.2 Encode and decode operations
               IX.1.2.1 OLT encode
               IX.1.2.2 ONU decode
               IX.1.2.3 Running disparity rules
               IX.1.2.4 Checking the validity of received code-groups
          IX.1.3 Eye mask and PMD
     IX.2 Miller and Miller squared scheme
          IX.2.1 Modified definitions for Miller code
               IX.2.1.1 Minimum extinction ratio
               IX.2.1.2 Launch optical power without input to the transmitter
          IX.2.2 Power spectral density of Miller code
          IX.2.3 Encode and decode operations
          IX.2.4 Eye mask
     IX.3 Raman mitigation suppression levels
Appendix X  Upstream PMD examples for TWDM PON
Appendix XI   Optical parameter specification for the S/R-CP reference point
Bibliography