SMPTE Standard for Television

SMPTE

SMPTE Standard for Television

Date:<2005-09-22>

SMPTE 297M

SMPTE Technology Committee N26 on File Management and Networking Technology

Serial Digital Fiber Transmission System for SMPTE 259M- and SMPTE 292M-Signals

Warning

This document is not a SMPTE Standard. It is distributed for review and comment. It is subject to change without notice and may not be referred to as a SMPTE Standard. Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to provide supporting documentation. Distribution does not constitute publication.

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ContentsPage

1Scope......

2Normative References......

3Optical transmission system specification (see Annex A for definitions of fiber terms)......

3.1Physical packaging and connectors of transmitter and receiver units......

3.2Transmitter unit for intra-facility links......

3.3Transmitter unit for inter-facility links......

3.4Receiver unit for intra- and inter-facility links......

3.5Optical fiber circuit and connector specification......

3.5.1Optical fiber type options......

3.5.2Optical connector return loss......

ADefinitions of optical domain transmission media and connector terms (informative)......

A.1Optical fiber and cable assemblies......

A.2Optical connectorization components......

BOptical transmission circuit design and performance options (Informative)......

B.1Tx and Rx unit selection criteria......

B.2Multimode and single-mode fiber transmission characteristics......

B.3E/O transducer digital signal processing limitation......

CLaser safety information (informative)......

DGlossary of Fiber Optic Terms (informative)......

EBibliography......

Foreword

SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United States of America, SMPTE has members in over 80 countries on six continents. SMPTE’s Engineering Documents, including Standards, Recommended Practices and Engineering Guidelines, are prepared by SMPTE’s Technology Committees. Participation in these Committees is open to all with a bona fide interest in their work. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU.

SMPTE Engineering Documents are drafted in accordance with the rules given in Part XIII of its Administrative practices.

SMPTE Standard SMPTE 297M-200x was prepared by Technology Committee N26.

SMPTE

Serial Digital Fiber Transmission System for SMPTE 259M- and SMPTE 292M-Signals

1Scope

This standard defines an optical fiber system for transmitting bit-serial digital signals. It is intended for transmitting SMPTE 259M serial signals (143 through 360 Mb/s) and SMPTE 292M signals (1.485 Gb/s and 1.485/1.001 Gb/s).

In this standard, “shall” denotes a mandatory provision of the standard; “should” denotes a provision that is recommended but not mandatory; and “may” denotes features included at the option of the designer whose incorporation makes the system performance, cost, and/or convenience of installation more attractive to the user.

2Normative References

The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below.

SMPTE 259M-1997, for Television — 10-Bit 4:2:2 Component and 4fsc NTSC Composite Digital Signals — Serial Digital Interface

SMPTE 292M-1998, for Television — Bit-Serial Digital Interface for High–Definition Television Systems

SMPTE EG 34-1999, Pathological Conditions in Serial Digital Video Systems

ANSI/ElA/TIA-492AAAA-A (2002), Detail Specification for 62.5 m Core Diameter/125 m Cladding Diameter Class Ia, Graded-Index Multimode Optical Fibers

ITU-T G.651 (1998), Characteristics of a 50/125 µm Multimode Graded Index Optical Fibre Cable

ITU-T Rec. G.652 (1997-04), Characteristics of a single-mode Optical Fibre Cable

IEC 60793-2 (2003-10) Optical fibres – Part 2: Product Specifications – General

IEC 60825-1 (2001-08) including Amendment 1, Safety of Laser Products, Equipment Classification Requirements, and User’s Guide

IEC 61754-15 (1999-09) Fibre Optic Connector Interfaces – Part 15: Type LSH Connector Family

IEC 61754-20 (2002-08) Fibre Optic Connector Interfaces – Part 20: Type LC Connector Family

3Optical transmission system specification (see Annex A for definitions of fiber terms)

3.1Physical packaging and connectors of transmitter and receiver units

For single-mode fibre applications, Tx and Rx unit optical domain connectors and their mating input and output cable sections shall be type LC/APC as per IEC 61754-20-7 or type LSH simplex plug connector interface – APC 8° as per IEC 61754-15-5.

For multi-mode fibre applications, Tx and Rx unit optical domain connectors and their mating input and output cable sections shall be type LC/PC as per IEC 61754-20-1 or type LSH simplex plug connector PC interface as per IEC 61754-15-1.

Note 1:Implementations that conform to previous versions of this specification may use SC/PC connectors as per IEC 61754-4-1.

The Tx unit light source shall be connected to its output optical connector via a short pigtail of single-mode fiber specified in ITU-T G652, if it is not physically installed and interconnected to that connector in a receptacle (see Annex A.1.4). A multimode 50/125 fiber pigtail per specification ITU-T G651 is acceptable if the Tx unit is intended exclusively for multi-mode link applications. The Tx unit or its product documentation shall indicate which type of pigtail, if any, is installed.

The Rx unit optical receiver shall be connected to its type input optical connector via a short length of 62.5/125 multimode fiber specified in ANSI/ElA/TIA-492AAAA-A (2002), if it is not physically installed and interconnected to that connector in a receptacle (see Annex A.1.4).

3.2Transmitter unit for intra-facility links

Depending on the specification of the transmitter input signal, an intra-facility link transmitter unit shall produce an intensity-varying optical output signal per Table 1 when either modulated by an electrical signal with specifications per SMPTE 259M or modulated by SMPTE 292M signal. Devices may be designed to accept both SMPTE 259M and SMPTE 292M as input signals.

Transmission circuit fiber8) / SM (9.0/125 m) / MM (50.0/125 m , 62.5/125 m) 1)
Light source type6) 7) / Laser / Laser or LED 2) 3)
Optical wavelength / 1310 nm ± 40 nm
1550 nm ± 40 nm
Maximum spectral line width between half-power points / 10 nm / 30 nm
Maximum optical power / – 7.5 dBm
Minimum optical power / – 12 dBm
Rise and fall times for SMPTE 259M Signals / As specified in SMPTE 259M for the electrical signal
< 1.5 ns (20% to 80%) with < 0.5 ns difference)
Rise and fall times or SMPTE 292M Signals / As specified in SMPTE 292M for the electrical signal < 270 ps (20% to 80%) / --
Extinction ratio4) / 5:1 minimum
Jitter (optical) 5) / As specified in SMPTE 259M for the electrical signal
Maximum reflected power / -14dB
Electrical/optical transfer function / Logic “1” maximum intensity
Logic “0” minimum intensity
NOTES
1)See ITU-T G.651 and ANSI/ElA/TIA-492AAAA-A for optional MM fiber type.
2)LEDs may not function reliably at higher bit rates specified in SMPTE 259M.
3)Tx units intended solely for multimode transmission link applications shall be so marked.
4)Is the ratio between the maximum and minimum output power of the transmitter.
5)UI = Unit Interval
6)Lasers are all class 1 as defined in IEC 60825-1 (2001-08).
7)A laser warning label that is clearly visible during maintenance, operations, and servicing should be present on equipment. Text borders and symbols must be black on a yellow background. The laser warning label shall be as illustrated:

Refer to Annex C for further information.
8)Optical fiber specification defined by IEC 60793-2 (2003-10).

Table 1 – Intra-facility optical transmitter output signal specifications

Transmitters for intra-facility links shall be labelled to indicate the polish of the connector, the payload types they support and the wavelength they use. The labelling shall have the format L-<polish>-<signal type>-<wavelength>. The element <polish> shall have the value APC to for angle polished connectors and the value PC for physical (flat polished) connectors. The element <signal type> shall have the value A to indicate support of SMPTE 259M signals only, the value B to indicate support of SMPTE 292M signals only and the value C to indicate support of SMPTE 259M and SMPTE 292M signals. The element <wavelength> shall have the value 1310 for 1310 nm transmitters and 1550 for 1550 nm transmitters.

Example:A physical (flat polished) intra-facility transmitter that supports SMPTE 259M signals and emits an optical signal with a wavelength of 1550 nm is labelled L-PC-A-1550.

3.3Transmitter unit for inter-facility links

Depending on the specification of the transmitter input signal, an inter-facility link transmitter unit shall produce an intensity-varying optical output signal per Table 2 when either modulated by an electrical signal with specifications per SMPTE 259M or modulated by SMPTE 292M signal. Devices may be designed to accept both SMPTE 259M and SMPTE 292M as input signals.

Transmission circuit fiber8 / SM (MM optional)
Light source type6) 7) / Laser
Optical wavelength / 1310 nm ± 40 nm
1550 nm ± 40 nm
Maximum spectral line width between half-power points / 4 nm
Maximum optical power 1) / +1 dBm
Minimum optical power 1) / – 3 dBm
Rise and fall times 2) / As specified in SMPTE 259M or SMPTE 292M for the electrical signal
Extinction ratio / 10:1 minimum
Maximum intrinsic jitter (optical) 3) / As specified in SMPTE 259M or SMPTE 292M for the electrical signal
Maximum reflected power / -14 dB
Electrical/optical transfer function / Logic “1” maximum intensity
Logic “0” minimum intensity
Notes:
1)Power is average power measured with an average-reading power meter.
2)Rise/fall times are measured following a fourth-order Bessel-Thompson filter with a 3 dB point at 0.75 x data rate in MHz, i.e., 0.75 x 270 Mb/s = 203 MHz.
3)UI = Unit Interval
4)Lasers are all class 1 as defined in IEC 60825-1 (2001-08).
5)A laser warning label which is clearly visible during maintenance, operations, and servicing should be present on equipment. Text borders and symbols must be black on a yellow background. The laser warning label shall be as illustrated:

Refer to Annex C for further information.
6)Optical fiber specification defined by IEC 60793-2 (2003-10).

Table 2 – Inter-facility optical transmitter output signal specifications

Transmitters for inter-facility links shall be labelled to indicate the polish of the connector, the payload types they support and the wavelength they use. The labelling shall have the format H-<polish>-<signal type>-<wavelength>. The element <polish> shall have the value APC to for angle polished connectors and the value PC for physical (flat polished) connectors. The element <signal type> shall have the value A to indicate support of SMPTE 259M signals only, the value B to indicate support of SMPTE 292M signals only and the value C to indicate support of SMPTE 259M and SMPTE 292M signals. The element <wavelength> shall have the value 1310 for 1310 nm transmitters and 1550 for 1550 nm transmitters.

Example:An angle polished inter-facility transmitter that supports SMPTE 292M signals and emits an optical signal with a wavelength of 1310 nm is labelled H-APC-B-1310.

3.4Receiver unit for intra- and inter-facility links

Depending on the specification of the receiver output interface, a receiver unit shall output either an electrical signal per SMPTE 259M, SMPTE 292M or an optical signal per SMPTE 297M when receiving an optical signal per Table 3. Devices may be designed to accept both SMPTE 259M, SMPTE 292M, or SMPTE 297M modulated signals

Transmission circuit fiber / Single-mode / Multimode2)
Minimum input overload power 1)3) / – 7.5 dBm minimum, +1 dBm recommended
Minimum input power1) / – 20 dBm
Detector damage threshold / + 1 dBm minimum
NOTES
1)Within the receiver input range, a BER < 10-12 shall be achieved with the SDI Matrix Checkfield signal. A BER < 10-14 isrecommended.
2)Multimode fiber is not recommended for SMPTE 292M signals.
3) Depending on product implementation, optical attenuators may need to be used to meet specified overload performance.

Table 3 – Optical receiver input signal specifications

Receivers shall be labelled to indicate the polish of the connector and the payload types they support. The labelling shall have the format <polish>-<signal type>. The element <polish> shall have the value APC to for angle polished connectors and the value PC for physical (flat polished) connectors. The element <signal type> shall have the value A to indicate support of SMPTE 259M signals only, the value B to indicate support of SMPTE 292M signals only and the value C to indicate support of SMPTE 259M and SMPTE 292M signals.

Example:An angle polished receiver that supports SMPTE 259M signals is labelled APC-A.

3.5Optical fiber circuit and connector specification

3.5.1Optical fiber type options

The user may use single-mode fiber for inter-facility links and either single-mode or multi-mode fiber for intra-facility links to establish a point-to-point optical circuit between the transmitter and receiver optical connectors. A point-to-point circuit may consist of one or multiple serially interconnected sections of the selected type of optical fiber in cables, jumpers, and/or patch cords. Mixing fiber types in the multiple sections of a point-to-point circuit is physically possible, but technically unacceptable.

Single-mode optical fiber shall comply with ITU-T G652 (1997-04; Characteristics of a single-mode optical fiber cable), and have a maximum attenuation of 0,35dB per kilometer at 1310 nm and 0.25dB per kilometer at 1550 nm.

Multimode optical fiber shall comply with ANSI/EIA/TIA-492AAAA-A (62.5/125 micron graded-index [GI] fiber) or ITU-T G.651 (50/125 micron graded-index [GI] fiber), and have a maximum attenuation of 1.5 dB per kilometer at 1310 nm.

Note:For multi-mode fibers, the maximum distance may be limited by the signal dispersion, which can be expressed as bitrate-length product. For 50/125 fiber typical bitrate-length product values are in the range of 1 GHz*km, and for 62.5/125 fiber typical values are in the range of 500 MHz*km, respectively. These values may vary with wavelength. As consequence, the dispersion of specific multi-mode fibers may be optimized for specific wavelengths.

3.5.2Optical connector return loss

Optical connectors shall have optical return losses as follows, with measurements performed at 23°C +/- 5°C, in accordance with IEC 60793-1-40 (2001-07) Measurement methods and test procedures – Attenuation.

Fiber Type / Minimum return loss
62.5/125 or 50/125 micron multimode / 20 dB
8-10/125 micron single-mode / 26 dB

Table 4 – Optical connector return loss

Note:The minimum return loss figures are specified to accommodate multiple in-line reflections.

SMPTE

ADefinitions of optical domain transmission media and connector terms (informative)

A.1Optical fiber and cable assemblies

Cables contain one or more sheathing-encased individual optical fibers, arranged in a bundle or flat ribbon configuration. Fiber counts selected for high-density cables will be the designer’s choice between the need for conduit space conservation and the need for convenient optical fiber cable management.

Jumpers, patch cords, and fiber circuit extenders are special-purpose optical fiber cables containing one or more fibers, each enclosed in a protective sheath.

Hybrid optical/copper cables are assemblies of one or more multimode and/or single-mode sheathed fibers, and two or more electrically-insulated copper wires or braids. They are fabricated for use in special applications such as interconnection of camera heads and base stations. Their specifications are to be defined in a separate SMPTE standard.

Pigtails are single fibers encased in a plastic material, but not including a protective sheath. They are fabricated for installation within terminal equipment to extend a fiber circuit from an interconnection panel receptacle to an optical device located within the equipment. They shall be terminated at the interconnection panel end in a type SC/APC or LSH simplex plug connector interface – APC 8°connector. The other end termination shall be made as recommended in relevant telecommunications industry practices.

A.2Optical connectorization components

Connectors are installed at both ends of all fibers in single, duplex, or multiple fiber patch cords, and sheath- protected multifiber cables. Connectors are also installed at one end of pigtails whose other end is physically affixed to optical Tx and Rx devices located within user equipment.

Adapters are installed in rack- and wall-mounted patch panels in telecommunications closets and equipment rooms to intermate connector-terminated fibers. They are the optical equivalent of double-ended BNC barrels or panel-mounted adapters used to interconnect tandem lengths of coaxial cable. Adapters provide mechanical means for precisely butting together projecting fiber connector ferrules. They are used to physically establish circuits consisting of serially-connected lengths of multimode and single-mode cable fibers or pigtails.

Adapters also accommodate the intermating of a single-mode light source output pigtail to a multimode transmission circuit input, and the intermating of a single-mode transmission circuit output to a multimode optical receiver input pigtail. Telecommunications industry practice allows the use of single-mode pigtails in a Tx unit to interface multimode fiber circuits. In an Rx unit, multimode pigtails may be used to receive optical signals from single-mode fiber circuits.

Receptacles are installed in terminal equipment to provide the interface between internally installed optical Tx and Rx devices and premises (plant) cabling circuits. A receptacle may physically comprise half of an adapter, with light sources or photo diodes physically installed in the other half. Such receptacles may be physically mounted on Tx or Rx unit PC boards. When a multimode or single-mode E/O or O/E transducer is mounted on a printed circuit board which cannot be physically located at the interface panel, interconnection to the panel receptacle is established by a pigtail (see 3.1).

BOptical transmission circuit design and performance options (Informative)

B.1Tx and Rx unit selection criteria

The power budget of a fiber optic transmission link is the arithmetic difference between the Table 1/Table 2 optical source minimum output power and the Table 3 optical receiver maximum input power. The minimum power budget required for transmission of a signal between source and destination equipment is the fiber’s attenuation at the desired transmission wavelength, plus the sum of the measured or specified losses at all splice points and in connectors, which may be as high as 0.5 dB per splice or connection. The system designer is advised to include a 3 dB to 6 dB “contingency” loss in setting up the loss budget of a long multi-section circuit.

Higher costs for single-mode Tx and Rx units needed to meet a specific loss budget may be offset by the use of lower cost multimode fiber throughout the circuit. However, the “minimum fiber bandwidth” of multimode fibers (expressed as a maximum “bandwidth-kilometer” value in the fiber specification) forces the use of single-mode fiber in any circuit that may eventually be required to transport 1.485 or 1.485/1.001 Gb/s SMPTE 292M-compatible signals. This fiber type choice requirement has no equivalent in coaxial transmission circuit loss calculations.