DSL Prime: The Fastest Cable in North America

A cable industry laggard prepares to leap past the competition.

by Dave Burstein of DSL Prime and Future of TV [December 5, 2005]

Fastest Cable in North America:
Double bandwidth & ready for DOCSIS 3.0
Cox's planned EON could support 100 Mbps upstream and down, as well as 200 more HDTV channels. Anton Wahlman expects Cox to become the first substantial customer of Vyyo/Xtend 3 gigahertz parts that allow twice as much throughput as today's typical cable systems. The system throughput can go as high as 9 gigabits split between about 100 homes, 2 to 10 times faster than Verizon's BPON and comparable to the GPON coming in 2007.

DOCSIS 3.0 has been the focus of cable upgrade plans, using the existing 860 MHz plant for dramatically more data bandwidth. Vyyo goes beyond that upgrade, by extending the frequency range, which they break into a doubled band for TV and downstream data and a third band for high speed upstream.

T-1s for cellular backhaul are a key Cox target. The revenue potential is enormous, because the Bells carved out a "cell site" exemption from unbundling rules and charge monopoly T-1 rates. One estimate is that 16 percent of all mobile revenue goes to cover T-1 charges, more than half the direct cost of the service. The Sprint Wireless/cable company deal alone offers enough T-1 revenue to more than pay for the deployment of Vyyo or other cable T-1 technologies.

The 3-gigahertz passive structure presumably will be deployed from the beginning, but some of the other high-end network gear will presumably be added over the years. DOCSIS 3.0 is still in the labs, and the 3.0 GHz extensions even further behind. The initial system will presumably have better data speeds than any of today's cable nets, but the blow away performance gains may be a few years in the future.

Will three gigahertz be the new cable network standard? The difference in new builds may only be a few dollars per customer, a modest investment in the future. When I asked a similar question six months ago, no one seemed interested. Perhaps today, with Verizon FIOS coming, the answer will be different.

100 up, 100 down, 1 small VDSL package
Infineon joins the game
The demo doesn't look like much, just a few boxes and boards on a small table, with a small screen. Nevertheless, the results are convincing—continuous, error-free 100 megabits downstream and 100 megabits upstream. The extra margin in the results made plausible the engineer's claim he could run 130 megabits both directions over the hundred foot cable if the test gear were slightly different. Actual equipment is in carrier's labs, including a cleanly designed DSLAM board whose maker I don't believe I'm allowed to mention yet.

Imran Hajimusa was especially proud of the analog engineers in Austria, who brought to VDSL2 years of automotive high voltage design. The result is a single chipset that works well across the entire range of VDSL2, from modest speeds up to one hundred megabits. A year ago, VDSL2 was designed with low speeds (25 Mbps down, only 2 to 5 Mbps upstream) for the West, higher speeds (50 to 100 megabits) for Japan and Korea. Deutsche Telekom has made clear that distinction is breaking down.

Infineon is finding quick acceptance for their VDSL2 reference design among ODMs who actually manufacture most of the world's modems, Hajimusa adds. Beside the VDSL2 multichip, the modem design is loaded with other Infineon chips including a network processor. Ethernet, voice ports, and wireless are standard features.

VDSL2 is crucial for Infineon's future. The company is spinning off the memory chip business amid losses, and will transfer most future manufacturing to Chartered Semiconductor and others. They do not intend to build a logic fab in the 65 nanometers generation. Infineon remains strong in automotive and industrial electronics, and needs to bring communications chips to profitability. Siemens, until 1999 the parent company, remains a key partner but has sold off their mobile phone division and has only a small share in DSL.

Being one of the first to market with a 100/100 megabit chips for both CO and CPE required a major investment, and Infineon has been hiring field staff throughout the world to service the markets. VDSL has potential for 10M ports in 2006, and likely explosive growth thereafter. If the chips deliver the performance in the field they are reaching in the lab, they have a winner here.

Editor's note: My original draft of the above used called the chips "VDSL," not "VDSL2." I changed it as a courtesy to some strong feelings at Infineon. They wanted to make the distinction. However, VDSL1 is so rare in the West, at least, that I don't think the distinction is worth making. Mathias Kurth, the chief German regulator, speaks simply of VDSL. I hope leaving out the numeral becomes the style, except when directly writing about standards or technology.

Copyright 2005 Dave Burstein.
The DSL Prime Newsletter is reprinted with permission.

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