100G challenges equipment design

By Stephen Hardy

Overview

Companies will perform design tasks while feeling the pressure of economic uncertainty, which may have as much impact on equipment design decisions as emerging standards.

Next year promises an emerging set of higher-speed standards and specifications that will shape technology development. But companies will perform these design tasks against a familiar backdrop of economic uncertainty—and that may have just as much of an effect on equipment design decisions.

How fast to high speed?

The IEEE 40- and 100-Gigabit Ethernet standards are due for ratification in June 2010. The fruits of the Optical Internetworking Forum’s (OIF’s) 100-Gbps DWDM work should finally begin to appear in 2010 as well. Meanwhile, the ITU-T/FSAN 10G GPON standards work should advance far enough to give technology developers a clear idea of their eventual target, one that those focused on 10G EPON already have in their sights.

I’ve touched on 10G PON in the FTTX forecast on page 19. As is the case with high-speed PON, leaders at technology developers have to determine whether the opportunity for high-speed equipment elsewhere in the network, particularly at 100 Gbps, is great enough to be worth the investment. The most optimistic predictions for “significant” 100-Gbps platform deployments begin with 2011, but just what does “significant” mean? I’m betting the initial roll-outs aren’t going to happen any faster than they have at 40 Gbps. This means that if you’re not one of the lucky few to get your foot in the door with early adopters (who probably aren’t going to use the technology in more than a few routes because the first wave of technology is likely to be very expensive), your timeline to full ROI isn’t going to look so good.

That said, most system vendors have lined up to take a shot, using homegrown technology. Certainly most of these companies are at least paying lip service to the OIF’s modulation scheme of choice, dual-polarization quadrature phase-shift keying with coherent detection (DP-QPSK/CD). However, some (such as ADVA Optical Networking—www.advaoptical.com) have already declared their intention to strike off in a different direction, and other companies are privately considering the same course of action.

The electronics associated with the coherent detection part of DP-QPSK/CD are very complex; coupled with the prospect of various modulation schemes in play, this is a nightmare scenario for module vendors. How many have access to bleeding-edge DSPs and analog-to-digital converters? Even worse, how about the algorithms associated with them—algorithms system houses are currently developing in hopes of creating competitive differentiation (which means resistance toward using the same algorithm as their competitors).

How successfully each module vendor addresses such issues will determine whether they have a role to play in the first wave of 100-Gbps technology development or will have to wait for the second wave—whenever that appears.