Rec. ITU-T G.989.2 Amendment 1 (10/2020) 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