Bell Labs puts 100 Gbps Ethernet to the test
Bell Labs demonstrates 100 Gbps transmission with Verizon and Deutsche Telekom
Accommodation of the global explosion in traffic can only be assured by
implementation of the most advanced high capacity optical metro/core transport
network technologies. Most of the optical technologies are based on 10 Gbps per
wavelength (channel), and this capacity needs to be increased by a factor of 10 per channel to
cope with the anticipated demand, giving an outcome of 100 Gbps per channel.
This made the recent demonstration of 100 Gbps transmission at Alcatel-Lucent's
Bell Labs (with participation of Verizon and Deutsche Telekom) that much more
impressive.
According to Bell Labs, to get from here to there, several challenges associated
with development and operation of ultra-high speed components and systems for
serial 100 Gbps optical transmission had to be overcome. These included stronger
transmission signal impairments associated with the upgrade of data rates due to
chromatic dispersion (CD) and polarization mode dispersion (PMD) which had to be
compensated or mitigated efficiently. Alcatel-Lucent has also improved the
complex integrated circuits for digital signal processing (DSP) and the
development of new very high speed components using state-of-the art electronics
and photonics.
Soon networks based on next generation 40/100 Gigabit Ethernet (GbE) transport
technologies will predominate and they will be based on standards currently
under preparation by several standards organizations (e.g., IEEE, ITU-T). Trials
by Alcatel-Lucent’s Bell Labs have demonstrated that it is possible on an
optical network originally designed for 10 Gbps to run 100 Gbps on that
platform.
In a 500km trial with Deutsche Telekom on a live optical network between
Darmstadt and Stuttgart they were able to transmit in parallel, 8 channels each at
100 Gbps.
Additionally, in another field trial with Verizon conducted between its Tampa
and Miami markets over an existing 504 km optical network, Bell Labs transmitted
live High Definition (HD) TV at 100 Gbps. These results were achieved using high
capacity Nx100 Gbps optical transmission over long-haul fiber links without
dispersion compensation units (DCU) using conventional 10Gbps DWDM platforms
with narrow channel spacing (50GHz) corresponding to a spectral efficiency of 2
bit/s/Hz. This advancement will enable service providers to keep up with the
demand for HD Video on Demand where customers 'want it now' and are not prepared
to wait for a lengthy download.
by Kendrick Struthers-Watson
Wed. December 17, 2008
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