By Mark Palazzo, VP and GM of Cisco’s Cable Access Business Unit
Here’s an important message from the Department of the Obvious: All along the world of networks, more capacity is needed. That’s especially true in the optical domain of the access/HFC plant, where work continues to multiplex more and more wavelengths together on a single piece of glass.
To date, operators tend to move traffic at or near the 1310 nm and 1550 nm wavelengths, to simultaneously transmit linear/broadcast as well as on-demand/narrowcast video streams on the access/HFC network.
As well, a lot of operators, and the vendor community that serves them, are considering the establishment of a full-spectrum, multi-wavelength plan for optical gear. It’s because we’re at this relatively early point that it’s critical to establish a common plan — because when wavelengths collide, bad stuff can happen.
At this week’s SCTE Cable-Tec Expo, two vendors in the optical equipment – our own Fernando Villarruel, and Venk Mutalik, VP/technology and strategy for Arris – will “leave their guns at the door,” so to speak, to co-deliver a paper and workshop about the importance of establishing a wavelength plan.
Wavelength management matters a lot these days, especially when considering a full-spectrum, linear and on-demand adaptation, in the C-band (1150 nm). Because this is relatively new, we and Arris did a lot of work to establish what impairments would need to be handled.
Top on that list is “four-wave mixing,” which will be detailed, as well as Stimulated Raman Scattering (SMR), Cross-phase Modulation (XPM), and fiber dispersion.
Why: Because there’s no shortage of competing, multi-wavelength plans on the market right now. Once you’re in, you’re in – changing wavelength plans later is expensive and messy. For those reasons, we felt it important to at least develop a set of technical constants to consider, when developing a multi-wavelength plan. Among them:
- A thorough analysis of FWM
- Plans to accommodate XPM
- Optical passives
- Number of wavelengths
Our intent is to provide operators with a C-band wavelength management plan, to increase capacity and expand services. The collaboration addresses multiple customer demands to ease the architectural complexities in the multi-wavelength environment.
“This agreement is the culmination of years of research in multi-wavelength technology to establish stable and robust full spectrum solutions for the MSOs” said John Caezza, President, ARRIS ATS Group.
“These efforts will also be used as the basis for future work on the CCAP platform” said Steve Condra, director of architectures for Cisco Cable Access Business Unit. “It is good to see two industry leading suppliers collaborate in a way that will ultimately benefit service providers.”