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Hi all, During the meeting in Geneva we agreed to adopt a maximum chromatic dispersion of 1600 ps/nm which is appropriate for 80 km of G.652 fiber. However at the recent SG15 Plenary Meeting in Geneva, a revised version of Recommendation ITU-T G.654 was consented, now including a new fiber type, G.654.E, which has been designed for very low loss and usage
in the C-band. While for G.652.D fibers a maximum attenuation coefficient of 0.3 dB/km is specified (and 0.35 dB/km for G.652.B fibers), for G.654.E fibers it is 0.25 dB/km over the wavelength range of relevance to our application space. Over an 80 km link
the total fiber attenuation could be 4 dB lower when using G.654.E fibers. This probably has significant impact on the OSNR at the output of the link. The revised version of G.654 is not yet available online from the ITU-T website, but will certainly be available during the course of the ct project. In the meantime we could send a Liaison Statement to ITU-T to liaise the consented revision of G.654. Because of the inherent characteristics of the black link, the fiber type is not specified in D1.2. For Ethernet applications usage of G.652 fibers is quite common, but for these longer distances we should not
preclude the usage of G.654.E fibers, which could be appealing to operators/users. The “disadvantage” of G.654.E fibers is a chromatic dispersion value, slightly higher than for G.652 fibers, namely 24.14 ps/nm at 1566.3 nm (currently the DWDM channel with the highest wavelength). Then the
maximum chromatic dispersion would be 1931 ps/nm over 80 km. I have created a comment to D1.2 to modify the maximum chromatic dispersion from 1600 to 2000 ps/nm. Furthermore because we are mostly likely not going to use G.653 fibers due to the risks of four-wave mixing (FWM) and as a result the minimum dispersion will not go below zero. Therefore I have created another
comment to modify the minimum chromatic dispersion from -200 ps/nm to 0. It would be good if individuals from fiber manufacturers participating in 802.3ct would confirm my assessments, including the market potential. Kind regards, Peter To unsubscribe from the STDS-802-3-DWDM list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-DWDM&A=1 |