COPPER BEYOND THE GREAT

In late May, a group of several dozen engineering types and other executives gathered in Geneva, to put the finishing touches on the VDSL2 standard. Over the course of a two-week meeting, during which sessions often lasted into the wee hours of the morning, the assemblage of talent produced a set of requirements that will allow carriers to push what was once thought to be the physical limitation of copper.

Under one plan, carriers will be able to offer up to 100 Mb/s both upstream and downstream over very short copper loops and, more typically for the U.S. market, up to 30 Mb/s over loops of 6000 feet. And though both SBC Communications and BellSouth drove the standard in large part, the vendors that are deeply involved in the VDSL2 market say it will definitely make an appearance in the independent telco market. At the same time, there also is an emerging school of thought that the way for independents to solve their high-speed needs is to bond multiple pair together using existing technology.

Ultimately, of course, the way to way to bring hundreds of megabits per second to the user is to bring fiber to every home. In some select areas that's already happening (see “FTTP Report Card,” May, The Independent), but it remains the exception and not the rule. For most carriers, the timeline to an all-fiber network extends well out past the end of the decade. Additionally, the insatiable demand for bandwidth isn't expected to abate any time soon. Over the past year it appears that many carriers have gotten the message that there is no such thing as providing too much bandwidth, according to Corey Geiger, general manager of OSP Broadband Solutions for UTStarcom, which recently bought Pedestal Networks.

“If you look at the requirements that are coming out now, we're talking about 50, 60 or even 70 Megs to the home now,” Geiger said. “When it comes to getting bits to the home, we know what the options are.”

Addressing that level is feasible with either VDSL2 or bonding techniques, though both technologies are still in the earliest stages. Of the two, bonding has been around as a concept for some time but has only recently started to hit the market. VDSL2, by contrast, has been put on the fast track to standardization only over the past 12 months as large carriers started feeling the heat from impending cable telephony competitors and accelerated their own video plans. As an additional benefit, though, independents have been presented with a couple of new options.

Under the plan adopted at the ITU meetings, VDSL2 has multiple “band plans” as well as deployment scenarios. Among those plans is one that will give carriers the ability to provide around 20 Mb/s at almost 7000 feet. According to Ikanos President and CEO Rajesh Vashist, about 80% of potential DSL subscribers can be reached by 5000 feet or less of copper. However, in the independent environment, where rural telcos dominate, the numbers tend to get a little skewed.

In its annual Broadband Survey last year, the National Telecommunications Cooperative Association found that more than 85% of its members were providing some kind of broadband services. However, one of the biggest gating factors sited by respondents as to why they couldn't provide greater speed was the length of their loops. VDSL2 certainly can give independents a speed boost for in-town customers and those near remotes, but the laws of physics come into play when trying to reach out to the truly rural users. Additionally, Vashist said, there will be other more practical problems when carriers begin to deploy the technology.

“One of the bigger issues to solve, particularly in the U.S., will be deploying VDSL2 in the same binder group as ADSL and not having it interfere,” he said.

For the past five years, Ikanos has focused on the VDSL market in Asia and is hoping to play off that practical experience in getting the second generation of the technology adopted in the U.S. Ironically, less than 10 years ago VDSL got its start among independents as a video transmission technology and continues to operate today among a handful of carriers, including Chibardun Telephone Cooperative in Wisconsin and Hutchison Telephone in Minnesota. However, it wasn't until the technology went through the full standardization process that the largest carriers started talking about adopting en masse. More important, the ability of Tier 1 players to drive down equipment prices should ultimately help independents justify the VDSL2 business case.

That business case, though, is changing rapidly regardless of carrier size or geography. Initially, telcos looked to VDSL as an enabling technology that would put them on par with cable TV's offerings. Now, telcos must begin to look beyond simply matching what cable can do and think about truly differentiating video services. Because it includes the ability to send massive amounts of data upstream (from the home to the network), VDSL2 lends itself in some ways to being the base technology upon which telco video can differentiate itself. UTStarcom's Geiger, in fact, believes that the new standards was being driven partly by a desire to increase upload speeds.

“I think you're going to see some additional enhancements around the uplink very soon,” he said.

Among the most significant will be the ability of users to send video upstream to servers, which can be accessed by anyone. In fact, many long-range thinkers in the vendor community believe the entire entertainment model will significantly change over the course of the next decade.

“Video is going to be a file that's distributed on the Web,” said Carl Russo, president and CEO of Calix. “My biggest concern is that service providers think of innovative services before they sell video.”

VDSL2, however, doesn't necessarily have a lock on the market. A number of vendors, led partially by chip maker Infineon Technologies, are counting on bonding as a way for carriers to provide super high-speed services without the risk of deploying a new technology like VDSL2. With bonding, two channels are combined to offer a cumulative bandwidth rate. In the case of ADSL2+, two channels bonded together gives carriers close to 35 Mb/s at loop lengths of at least 6000 feet.

Particularly interested in the technology are customer premises equipment vendors, which can quickly adapt their existing technology to the bonded environment. Comtrend, for instance, recently developed a residential gateway based on bonding that the company is testing with two U.S. carriers. Initially, the Irvine, Calif.-based company targeted Bell companies; however, it's finding that independents are better suited for bonding.

“I think you'll see the IOCs launching first based on their ability to turn things around fast,” said Andrew Morton, general manager of North and South America for Comtrend.

The catch with bonding, though, is that it requires multiple pairs, a fact VDSL2 proponents are quick to point out.

“The real issue is financial,” Ikanos' Vashist said. “Is it viable to bring two pairs? Those who feel it's better to bring two lines to the house are in the minority. Typically, taking two copper wires and bonding them is financially less attractive. But in some places, it will have to be viable.”

Others point to the added cost of managing multiple pairs.

Morton, however, believes for independents that built networks over the course of decades, the financial burdens are insignificant, particularly when compared with the benefits it provides.

“The telcos are sitting on a lot of unused copper right now, and it can be used,” he said.