| Work group:
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Q6/15 (Presentation Web page is available here)
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| Title:
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Characteristics of optical components, subsystems and systems for optical transport networks
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| Description:
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1 Motivation
Optical fibre networks are deployed in telecommunication systems worldwide. Structural reforms leading to increased privatisation of telecommunications networks create an operating environment requiring optical networking and interconnection among different carriers.
Developments are being fuelled by the need for improved network efficiency, customer demand for ever higher bit rate data services, high-speed Internet access, and other innovative services.
This leads to a push for higher bitrate (terabit/s) optical transport systems in the intra-office, inter-office, metro and long-distance networks of the various network operators.
The Question defines specifications needed for physical layer interfaces of single channel and multiple channels (e.g., WDM and SDM systems), to enable the evolution of optical networks to support the ubiquitous availability of next-generation high-bandwidth services, for example, supporting the evolving needs of mobile communication networks (e.g. support of IMT 2020/5G and the evolution to IMT 2030/6G), data centres, cloud computing and the metaverse.
To the greatest extent possible, these specifications should enable transverse compatibility (black-box and/or black-link) in a multi-vendor, multi-network-operator environment.
Furthermore, the increasing complexity of optical networks has brought about an increasing diversity of active, passive and hybrid or dynamic/adaptive optical components and subsystems with functions differing with the application. Specification of the optical aspects of systems used to monitor the integrity of these complex networks e.g. fibre sensing systems and applications, are required to help ensure such systems provide useful data and do not interfere with live traffic. Processing of data gathered in the optical transport network may include the use of artificial intelligence/machine learning (AI/ML). This Question also addresses the high-level need for specifications expressed by the system Recommendations and network operators. It serves as an interface to the component level standards generated outside of ITU-T in organizations such as IEC.
The following major Recommendations, in force at the time of approval of this Question, fall under its responsibility: G.640, G.661, G.662, G.663, G.664, G.665, G.666, G.667, G.671, G.672, G.680, G.691, G.692, G.693, G.694.1, G.694.2, G.695, G.696.1, G.697, G.698.1, G.698.2, G.698.3, G.698.4, G.698.5, G.698.6, G.955, G.957, G.959.1 and G.911.
2 Questions
Study items to be considered include, but are not limited to:
- What system aspects and physical layer characteristics are necessary to enable longitudinally compatible and transversely compatible optical systems in intra-office, inter-office, metro and long-distance networks?
- What components aspects and desirable characteristics need to be specified to support intra-office, inter-office, metro and long-distance networks, and additionally, local access networks and submarine networks?
- What enhancements to existing draft or published Recommendations and what new Recommendations are necessary to specify interfaces for optical transport systems, employing both direct detect and coherent technologies?
- What systems and physical layer considerations are necessary for optical transport systems optimized for new applications for example metro applications, including mobile fronthaul and backhaul?
- What enhancements should be made to existing draft or published Recommendations to reflect technological developments, further reduce the cost and power consumption, and improve the reliability of the optical fibre communication systems?
- What are the general considerations for optical systems used to transport OTN, Ethernet, CPRI/eCPRI and other protocols using several types of single-mode fibre, including SDM fibre?
- What statistical and semi-statistical design approaches, (e.g., for power budget) can be used in Recommendations?
- What specifications are required to enable transverse and longitudinal compatibility in single-channel and multichannel optical systems?
- What system models, reference configurations and reference points are required to support optical interface specification methodologies?
- Which specifications of interfaces inside a DWDM link, with both fixed and flexible grids are required?
- How do we evaluate the quality of an optical channel to enable end-to end routing decisions in all optical networks (accumulated effects of degradations, transients, etc.)?
- What quality metrics, such as error vector magnitude and Q factor are required?
- What physical layer architectures including new technologies to increase optical transmission systems capacity can be used to make operation of the optical network more efficient?
- What physical layer architectures and optical transmission technologies can be employed to improve the network's energy efficiency?
- What account do we need to take of linear and nonlinear propagation effects?
- What performance and link monitoring techniques, including distributed fibre optic sensing, are useful?
- Which applications in terrestrial and free space optics optical transmission systems require forward error correction (FEC) techniques to enhance system margin?
- What should Recommendations say about the availability and reliability aspects of optical systems?
- What aspects of active devices and sub-systems such as optical amplifiers (OAs), including parameter definitions and measurement, classification of devices and sub-systems, optical nonlinearities, polarization, dispersion, noise and transients should be specified?
- What aspects of passive components such as splices and connectors, attenuators and terminators, M-by-N branching components (such as splitters and combiners), wavelength optical multiplexers and demultiplexers, optical filters, optical isolators and circulators and dispersion compensators should be specified?
- What are the worst-case transmission parameter values (for all environments and to end-of-life) for passive components in digital applications?
- Which components and subsystems should be specified for use in bi-directional transmission systems on a single fibre?
- What specifications should be provided for fixed optical add/drop multiplexers (OADMs), re-configurable optical add/drop multiplexers (ROADMs) and optical cross-connects (OXCs)?
- What safety aspects of considered components, including aspects of operation at high optical power levels should be specified?
3 Tasks
Tasks include, but are not limited to:
- Enhance Recommendations G.640, G.661, G.662, G.663, G.664, G.665, G.666, G.667, G.671, G.672, G.680, G.691, G.692, G.693, G.694.1, G.694.2, G.695, G.696.1, G.697, G.698.1, G.698.2, G.698.3, G.698.4, G.698.5, G,698.6, G.955, G.957 and G.959.1.
- Develop new Recommendations, supplements and/or combine existing Recommendations from progress on the above study points.
- Enhance the text of G-series Supplement 39.
An up-to-date status of work under this Question is contained in the SG15 work programme (https://www.itu.int/ITU-T/workprog/wp_search.aspx?sp=18&q=6/15).
4 Relationships
Recommendations:
- G.6xx and G.9xx Series
Questions:
- 2/15, 3/15, 5/15, 7/15, 8/15, 10/15, 11/15, 12/15, 13/15, 14/15
Study Groups:
- ITU-T SG5
- ITU-T SG13
- ITU-T SG12 network performance objectives
Other bodies:
- IEC SC86B on optical passive components
- IEC SC86C on active components and dynamic components including all types of optical amplifiers, on system measurement test methods and on optical amplifier test methods
- IEC TC76 on laser safety and aspects of safe laser operation
- OIF on optical systems interfaces
- IEEE 802.3 on optical systems interfaces
- IETF CCAMP working group
- OpenROADM MSA
- SmartTuning MSA
- MOPA
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| Comment:
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Continuation of Q6/15
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Rapporteur:
| Mr. | Fabio | CAVALIERE |
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Associate rapporteur:
| Mr. | Shikui | SHEN |
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