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ITU-T Study Group 15 List of Questions Under Study (Study Period 2005-2008) |
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ITU-T SG 15 Question 8/15 |
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Characteristics of optical fibre submarine cable systems (Continuation of Question 18/15)
- Motivation
The transmission capacity within each country and/or between countries has
been rapidly growing due to the evolution of Internet services on a global scale.
Optical fibre submarine cable systems at the heart of global networks are
affected by such an increase in transmission capacity. In such a seamless
global network, connectivity also becomes more important than ever for
telecommunication carriers and providers. The optical fibre submarine
cable systems include the two types of system, repeatered systems and
repeaterless systems. Repeaterless submarine cable systems are being
used for network extensions because of lower cost for installation and OAM.
On the contrary, repeatered systems are being used for the long haul large
capacity transmission by introducing new fibre technologies including optical
amplifiers.
This question has responsibility for the following areas of standardization related to:
- Specifications of terminal equipment, optical fibre cables in
optical fibre repeatered submarine cable systems with various
optical amplifiers such as Erbium Doped Fibre Amplifiers (EDFAs)
and Raman amplifiers
- Specifications of terminal equipment and optical fibre
cables in optical fibre repeaterless submarine cable systems,
including systems with remotely pumped optical amplifiers
- Specifications of test methods concerning the terminal
equipment, optical fibre cables and other equipment relevant
to the submarine cable systems
- Specifications of forward error correction (FEC) for optical
fibre submarine cable systems
Note: Marinised terrestrial cables (as defined in Recommendation G.972)
are allocated to ITU-T SG 6.
The following major Recommendations, in force at the time of approval
of this Question, fall under its responsibility: G.971, G.972, G.973,
G.974, G.975, G.975.1, G.976, G.977.
- Question
- How should Recommendations G.971, G.972, G.973, G.975.1, G.976
and G.977 be amended from a viewpoint of cost effectiveness?
- What new transmission techniques should be recommended to
increase transmission capabilities of optical fibre submarine cable systems?
- What new components and subsystems (fibre, component, etc.)
should be utilized to improve system capacity and reliability?
- What new test methods are necessary for the submarine cable systems?
- What mechanical protection and system protection mechanisms should
be recommended for high capacity submarine cable systems to improve
systems reliability/availability?
- What terrestrial and submarine integration should be recommended
for the effective network systems?
- What new Recommendations are necessary?
Study items to be considered include, but are not limited to:
- Transmission characteristics of optical fibre submarine cable systems
- Interface characteristics of optical fibre submarine cable systems
- Mechanical characteristics of the submarine portion of optical fibre
submarine cable systems
- Test methods
- Evolution of submarine systems to higher bit-rates, including
the effects of chromatic dispersion, polarization mode dispersion,
and optical fibre nonlinearities
- Dispersion accommodation techniques including dispersion
management transmission lines and/or hybrid transmission lines
for high speed optical fibre submarine cable systems
- Adoption of wavelength-division multiplexing/ demultiplexing techniques
- FEC (Forward Error Correction) for high bit rate DWDM submarine systems
- Introduction of other types of fibre amplifiers, Raman amplifiers,
distributed Raman amplifiers or semiconductor amplifiers operating at different wavelengths
- Flexibility for partial network upgrades
- Repeaters with optical amplifiers
- Use of branching devices in submarine networks
- Availability and reliability
- Operations and maintenance
- Interface compatibility of submarine and terrestrial systems
- Terrestrial and submarine integrated networks
- Mechanical and systems level protection mechanisms
- System and cable repair procedures
- Optical submarine systems based on soliton transmission techniques
- Tasks
Tasks include, but are not limited to:
- Revisions to Recommendations G. 971, G. 972, G.973, G. 975.1,
G. 976, and G.977 as required
- Continue and complete the work on new Supplement (dsnsub)
covering design guidelines for optical fibre submarine cable systems
- Continue updating the data on cable ships and submersible equipment (as required)
- Develop additional Recommendations from progress on the above study items
Note: An up-to-date status of work under this Question is contained in the
SG 15 Work Program.
- Relationships
- Recommendations:
- G.65x series, G.707, G.709, G.95x series, G.96x series
- Questions:
- Q5/15, Q6/15, Q7/15, Q11/15 and Q14/15
- Study Groups:
- ITU-T SG 6 on other types of underwater cables (e.g. marinised terrestrial cables)
- ITU-T SG 13 on error performance
- Standardization bodies, forums and consortia:
- IEC SC86A on fibre reliability and on underwater cables
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