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Question 5/15

Question 5/15 - Characteristics and test methods of optical fibres and cables
(Continuation of Question 5/15)
Motivation
Optical fibre cables have been specified and deployed in telecommunication networks worldwide, finding wide application in local access networks, interoffice and long distance networks, and submarine networks. New optical fibre technologies and new applications continue to drive the need for additional specifications. For example, the growing demand for broadband services (multimedia, high-speed internet, HDTV, etc.) to and in buildings and homes requires the introduction of high-capacity transmission media into the local networks. Optical fibre is an important option for these purposes.  Moreover, the widespread deployment of broadband services requires a new class of optical fibre that can substantially expand the transmission capacity of a traditional single-mode fibre.
The responsibility under this Question includes the following areas of standardization:
  • The description and testing of basic single-mode and multimode fibre types, with parameter tables describing the variations within each of the basic types.
  • Definitions of attributes and associated test methods for geometrical, transmission, mechanical and reliability characteristics.
  • Descriptions of different possible fibre solutions for local access networks.
  • Descriptions of relationships between the different attributes with other attributes and with variations in the environment.
  • The following major Recommendations, in force at the time of approval of this Question, fall under its responsibility: G.650-series, G.651.1, G.652, G.653, G.654, G.655, G.656, G.657. The following Supplement also falls under its responsibility: G.Sup40, G.Sup.47.
Question
What fibre characteristics are needed to:
  • Support bit-rates up to and above 100 Gbit/s with time-division multiplexing (TDM)?
  • Open new spectral transmission regions as the passband of optical amplifiers increases and as the number of wavelength-division multiplexed channels increases?
  • Support Dense Wavelength Division Multiplexing (DWDM) applications in access, metropolitan, long distance and submarine networks?
  • Support Coarse Wavelength Division Multiplexing (CWDM) applications across the full spectrum mainly in access and metropolitan networks?
  • Support parallel space division multiplexing applications?
  • Support space- and/or mode-division multiplexing applications?
  • Improve the nonlinear optical performance limits optical fibres for high bit rate transmission beyond 100 Gbit/s
What is needed to provide cost-effective optical access networks to and in buildings and homes?
  • How can cohesive Recommendations on the optical access network cabling be formulated? These could be divided by the main types of topology and could include aspects such as:
  • Optical fibre
  • Cable constructions
  • Installation techniques impact on fibre characteristics
  • Impact of hardware, such as splicing trays, customer outlet …, on fibre characteristics 
  • Hardware
  • Reliability
  • Testing and maintenance
NOTE: Some of these aspects are, at present, covered also in Q16/15 so coordination is necessary.
Study items to be considered include, but are not limited to:
  • Geometrical, mechanical, and optical properties of the glass and coating, for single-mode fibre applications.
  • Reliability of fibres and cables (lifetime and failure rate) under a wide variety of temperature and humidity environments; long-term aging.
  • Definition, modelling, and measurements of Polarization Mode Dispersion (PMD) relationships with chromatic dispersion, polarization dependent loss (PDL), and with time and temperature.
  • Possible additional fibre types, and additional parameter tables within the existing Recommendations.
  • Other types of traditional single-mode silica fibres optimized for higher bitrates (e.g. above 100 Gbit/s) DWDM systems.
  • Other types of traditional single-mode silica fibres for opening new spectral transmission regions (as the pass-band of optical amplifiers increases.
  • Other types of traditional single-mode silica fibres for reducing non-linearity effects (as the channel spacing becomes smaller).
  • Optical fibres made by materials different from silica (e.g. fluoride fibres, chalcogenide fibres, polycrystalline fibres, plastic, etc.).
  • Length uniformity of fibre geometrical and transmission characteristics that have a functional impact on systems, and are not merely a quality control issue.
  • Dispersion management of high-performance systems.
  • Fibre damage from high power and small bend radii.
  • Fibre and cable, requirements for parallel transmissions on either CWDM or Space division multiplexing on single-mode or multimode fibres at above 100 Gbit/s.
  • Fibre and cable, requirements for space- and/or mode-division multiplexing on single-mode or few-mode fibres at above 100 Tbit/s/fibre.
  • In-home and in-building optical network beyond the network termination point, taking into account the strong relationship between fibre, cable, connection hardware, network topology and operating speeds, and installation techniques. Strategies for mixed transmission media such as hybrid fibre/coax.
  • Define a “degree of compatibility” between the different types of fibres installed in the same link in order to estimate the transmission characteristics in terms of expected loss (e.g. define the expected limits of splice loss, connectors loss…), chromatic dispersion, PMD…..
  • Define fibre parameters in the monitoring wavelength region (up to 1650 nm).
Tasks
Tasks include, but are not limited to:
  • Modify parameters in Recommendations G.651.1, G.652, G.653, G.654, G.655, G.656, and G.657.
  • Update the text of G.Sup40 and G.Sup.47, as required.
  • Develop new Recommendations or parameter tables within existing Recommendations for possible additional fibre types.
  • Develop definitions of new parameters, and corresponding factory and field test methods, RTMs and ATMs, for G.650.1, G.650.2, and G.650.3.
  • Develop guidelines for users of optical fibres and cables.
  • Develop cohesive Recommendations on the cabling of optical access networks to and in buildings and homes.
NOTE: An up-to-date status of work under this Question is contained in the SG15 Work Programme at:
http://www.itu.int/ITU-T/workprog/wp_search.aspx?Q=5/15
Relationships
Recommendations:
  • G.65x- and G.95x- and L-series Recommendations
Questions:
  • Q1/15, Q2/15, Q5/15, Q6/15, Q7/15, Q8/15, Q16/15, Q17/15
Standardisation bodies, forums and consortia:
  • ISO/IEC JTC1/SC25 on multimedia cabling of homes
  • IEC SC86A on fibres and cables
  • IEC SC86B on connectors and components
  • IEC SC86C on system testing and active devices
  • CENELEC TC86BXA, TC86A