SCTE member since 1995 Title : Director of Technical Marketing, Filtronic Sigtek Broadband Background : Volpe is a leading expert on troubleshooting DOCSIS networks. While at Filtronic Sigtek, he pioneered the ST-261 DOCSIS Protocol Analyzer. Volpe started his career in cable as an RF engineer at C-COR, where he developed C-CORs hum-modulation and noise power ratio test setups and co-authored several SCTE standards. He holds two EE degrees: an MS from Johns Hopkins Applied Physics Laboratory and a BS from Penn State. How did Sigtek get into the DOCSIS arena? Filtronic Sigtek’s entry into the DOCSIS arena is a David and Goliath story. Agilent was developing a DOCSIS protocol analyzer for CableLabs but having trouble meeting the deadline. A DOCSIS protocol analyzer simply demodulates the RF data signals carried between the CMTS and the cable modems and translates them into a human readable format. CableLabs contacted Sigtek, and we were able to deliver the first prototype within three months. We have maintained our position in CableLabs’ test environment since 1999. A year- and-a-half later, tComLabs started in Europe (the Euro-DOCSIS equivalent of CableLabs), and we created a Euro-DOCSIS protocol analyzer. What explains your early bet early on FPGA technology? Field programmable gate arrays (FPGAs) have been strategic to Sigtek’s success. Because they are reprogrammable at any time, they are adaptable to changes in technology. This has been crucial for the success of the DOCSIS protocol analyzer. The DOCSIS specification and DOCSIS chipset vendors have made many subtle—and some not so subtle—changes over the years. FPGA technology has enabled Sigtek to keep our customers up to date by with these changes by simple software downloads. Anything else you do uniquely at the chip level? Burst demod! We are the only company in the industry that has a real-time burst demodulator in our FPGA chips that can detect a modem’s signature, demodulate it, filter on its MAC address, and provide useful information to the user such as the specific modem’s MER. This sets us apart. You market more to test labs and manufacturers than operators, correct? Well, yes and no. We started out focused on CableLabs, tComLabs, and manufacturers of DOCSIS equipment. A few years ago, we started selling DOCSIS protocol analyzers into the test labs of some of the major MSOs. At this time, I started working with cable operators to understand what types of problems they were having in managing and troubleshooting their DOCSIS networks. Soon it became clear that there was a major blind spot for cable operators between the CMTS and the cable modems. This part of the plant is where data was modulated on RF carriers and could only be tested with RF tools. A lot of finger-pointing was happening out the field between RF technicians and IT specialists, but cable modems were still offline. We built a portable version of our DOCSIS protocol analyzer to remove the blind spot. The same capability used to develop DOCSIS equipment has proven to be tremendously powerful in troubleshooting DOCSIS networks, particularly when deploying VoIP. The operator side is now the quickest growing sector of our DOCSIS business. Do you keep track of ongoing DOCSIS developments? Any predictions? Of course, we need to make sure that our DOCSIS protocol analyzers are up to speed with the latest spec. DOCSIS 3.0 looks like a real value proposition coming down the road. With upstream bundling in DOCSIS 3.0, subscribers—cable operators—will really be able to have symmetrical upstreams. In DOCSIS 3.0, a single cable modem will be pushing out four upstream signals at a time in QPSK or 16-QAM. This would give you four times the upstream capacity of today’s modems, operating in the same upstream conditions. What’s happening in your other (non-cable) markets? We are involved in both the cellular and defense industry, which both happen to be booming. How does cable stack up against other industries? I’ve been in cable since the early ’90s, and as many say, "it gets in your blood." The governmental and commercial sides of any industry will have fiscal ups and downs, so if you are going to choose, pick one that’s fun—which for me is cable. So it’s no wonder that most of my time at Sigtek is spent on the DOCSIS product line. The relationships formed seem much closer than on the governmental side. I find it increasingly difficult to go to any city and not know someone from the cable industry who I don’t genuinely think is a good person.

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