COLOGNE, Germany -- A new initiative designed to vastly increase the fiber capacity of the cable HFC network is set to come out by the end of this month.

Speaking at the ANGA Com cable show here last week, Dr. Alberto Campos, a fellow at CableLabs , said work is just about complete on the Full Duplex Coherent Optics tech specification. He said the cable R&D organization plans to publish the new coherent optics scheme, which will actually be part of the group's larger new Point-to-Point Coherent Optics specification, by the end of June.

Under development for the past year, Full Duplex Coherent Optics will enable cable operators to dramatically boost their bandwidth for data, video, voice and other services by doubling the bi-directional capacity of each access network fiber as well as multiplying the overall capacity of each fiber by over 200 times, according to CableLabs. The work builds on the R&D group's efforts to apply coherent optics -- a technology typically found in long-haul and metro optical networks -- to cable's much shorter, last-mile broadband infrastructure by enabling optical signals to run both ways over the same fiber link. (See CableLabs Gives Optical Fiber a Massive Efficiency Boost and New CableLabs Optical Tech Promises Big Bandwidth Boost.)

CableLabs is working on Full Duplex Coherent Optics in parallel with its efforts on Full Duplex DOCSIS 3.1, a separate, higher-profile spec also designed to boost the capacity of the cable HFC network by enabling upstream and downstream signals to use the same bandwidth on the DOCSIS part of the network. Both Full Duplex initiatives are heavily dependent on cable operators driving fiber much deeper into their access networks, splitting many more fiber-optic nodes and eliminating the need for amplifiers, thereby upgrading to a node plus zero architecture.

Due to this costly and burdensome requirement, it's not clear how many cable operators will actually be able to take advantage of either new spec, at least in the short run. That's especially true in Europe, where most of the cable plant is installed underground rather than attached to utility poles. (Look for more on Full Duplex DOCSIS 3.1's European challenges in a later story this week.)

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Nonetheless, cable technologists see great promise in applying coherent optics technology to the cable access network. With the help of Dense Wavelength Division Multiplexing (DWDM) technology, they claim it can double the whole fiber system capacity and work with 100-Gigabit, 200-Gigabit and future 400-Gigabit systems. "You'll have significant capacity for years to come," Campos told the ANGA audience.

For now, CableLabs is focusing on coming out with a spec for 100-Gig systems. But, if all goes according to plan, an updated spec for 200-Gig networks or even 400-Gig networks could be available in the near future. Once the spec is released, CableLabs expects to move into initial lab trials of the technology next year.

— Alan Breznick, Cable/Video Practice Leader, Light Reading