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OPTICAL FIBRES ENABLE BREAKTHROUGH
IN LARGE-CAPACITY MULTIBAND
WAVELENGTH TRANSMISSION
Fujitsu Limited and KDDI Research have jointly O-band (1,260nm to 1,360nm).
developed a large-capacity multiband
Construction of a simulation model that accounts
wavelength multiplexing transmission technology
for the degradation factors of transmission
utilising optical fibres.
performance in multiband transmission enabled
This development, undertaken as part of the the transmission design of multiband wavelength
‘Research and Development Project of the multiplexing systems. This model reflects the
Enhanced Infrastructure for Post-5G Information measurement results of the commercial optical fibre
and Communication Systems’ commissioned by characteristics and the transmission parameters
Japan’s New Energy and Industrial Technology extracted by the experimental system verification
Development Organisation (NEDO), enables of the integrated wavelength converter/multiband
transmission of wavelength bands other than amplifier. The result was realisation of high-precision
the C-band, which has not previously been simulations that reduce errors from the actual
achieved in medium and long-distance optical measurement by 1dB, making it possible to take into
communications. The optical fibre network account the interaction between bands and the
introduced enables wavelength transmission at degradation of transmission performance.
5.2 times the wavelength multiplicity of current KDDI Research made it possible to utilise twice the
commercial optical transmission technology, in frequency bandwidth of the conventional C-band
contrast to the traditional optical fibre networks in the O-band, which has so far never been utilised
that use single-mode fibres with light passing in high-density wavelength division multiplexing
only through the centre of the optical fibre with just (DWDM) transmission.
the C-band (1,530nm to 1,565nm) as the signal
By combining these two technologies it became
transmission band of the optical network.
possible to conduct experiments using existing
With the ever-increasing amount of communication optical fibres to demonstrate multiband wavelength
traffic, the C-band alone is envisaged to have multiplexed transmission over a distance of 45
insufficient transmission capacity, hence the need to kilometres in the O,S,C,L and U bands and so prove
increase transmission capacity per fibre. Fujitsu and that wavelength transmission is possible at 5.2
KDDI Research have therefore aimed to increase times the wavelength multiplicity of conventional
the wavelength band used from the C-band to the C-band only transmission. The two companies
L-band (1,565nm to 1,625nm), the S-band (1,460nm to also confirmed multiband wavelength multiplexing
1,530nm), the U-band (1,625nm to 1,675nm) and the transmission over 560km in the S,C,L and U bands.
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