August 27, 2008

Zhone expands copper’s boundaries

Extending an all fiber to the home (FTTH) network to every home may be the ultimate broadband dream, but in reality, most traditional service providers are taking a more prudent approach.

This approach calls for service providers to take fiber all the way to homes in greenfield builds but a hybrid mix of fiber and existing copper in brownfield networks.

In response to the service provider’s need to address today’s hybrid copper and fiber environment, Zhone has debuted two new IP DSLAMs that accommodate both VDSL2 and ADSL2+ in either single or bonded-pair copper modes.

Addressing the emerging need for VDSL2 services, the Bitstorm HP is a 24 port VDSL2 IP DSLAM that can deliver up to 100/100Mbps symmetrical services on each port with additional support for ADSL2+ (see Figure 1.)

As the second product in the series, the Bitstorm RP (Reach Performance) can provide 48 ports of ADSL2+ in either a single-pair or bonded-pair configuration to deliver 45 Mbps over short loops and up to 25 Mbps at up to 10,000 feet from the CO.

Unlike many products that emerged in the late 1990s that often preceded any customer demand, Zhone’s debut of the two new platforms were accompanied with the announcement that two customers are already using the product in their respective networks: Maine-based independent ILEC Tidewater Communications and Finland-based Netmedia.

“Zhone has done a very good job this year of keeping a steady flow of new product announcements coming out of the company,” said Teresa Mastangelo, principal analyst of broadbandtrends.com. “It wasn’t like it was an announcement for a product that’s coming out in a couple of months, but a product that’s generally available and is in use by a number of customers already.”

Leverage and extend
During the February 2008 FTTH European Council trade show held in Paris, France, France Telecom--arguably one of Europe’s most aggressive purveyors of FTTH with about 300,000 homes passed—candidly admitted that the take rate for their FTTH service was relatively low.

The problem was not so much the technology, but their ability to properly market the service since it lacks the same scale of traditional DSL and copper-based services.

What this suggests is incumbent service providers realize that the payback on rolling out FTTH is a long-term proposition and in the meantime are looking for options that can leverage their existing copper plant while pushing fiber closer to the customer where it economically makes sense.

“The problem France Telecom has is they can’t market in the same they would market their other services,” said Mastrangelo. “When you just have pockets of availability, you have to go door to door and tell people the service is available, and it’s a very expensive acquisition process because there’s no scale they can leverage on their marketing. Whereas when you have copper you don’t have those obstacles in the way; everyone has the copper and it’s being able to just add a new service to a building or a faster speed or whatever the operator is choosing to do with that VDSL2 link.”

Not a vendor to engage in religious technology wars, the two new 1RU IP DSLAM platforms have various deployment options.

Both platforms can be deployed in three main scenarios: MDU/MTU Fiber to the Business (FTTB)/Fiber to the Curb (FTTC) configuration with VDSL2/ADSL2+; bonded ADSL2+ from the CO; or in a Fiber to the Node/Neighborhood configuration with either VDSL2 or ADSL2+ from a RT cabinet.

The desire by service providers to leverage and extend their existing copper plant has prompted vendors like Zhone to be more flexible with their respective offerings. “All vendors are finding that there’s no single architecture that meets the needs of every operator, so vendors like Zhone are looking at all the different ways to leverage the equipment they have, modify it, and repackage it to continue to provide solutions that help their operators drive new services.”

Still, copper, even on the shortest of loops, are far from perfect.

Existing copper links can be plagued with various impairment issues such as Near End CrossTalk (NEXT), Far End CrossTalk (FEXT), Impulse Noise and Radio Frequency interference. These issues can degrade the performance of the experience of higher end applications such as HDTV and gaming (see figure 2).

To address crosstalk issues, the Bitstorm HP IP DSLAM, for example, leverages Ikanos Communications’ silicon which enables it to perform crosstalk management at distances of up to 5,000 feet.

Meanwhile, Bitstrom RP, a code extension of the existing Paradyne/Zhone DSLAM series, provides ADSL2+ bonding, built in splitters and dual GigE and far end uplink ports. In addition, the product features include hot-swap serving and single click configuration with automatic line recognition.

An MDU play
While US-based FTTH frontrunners such as Verizon Communications have been aggressively bringing fiber to Multi Dwelling Units/Multi Tennant Units (MDUs/MTUs) in areas like New York, NY via its FiOS rollout, the majority of MDU/MTU broadband growth has come outside of the U.S., particularly in Asia-Pacific and Europe.

Even though deployment scenarios will vary, typically service providers will bring a fiber into a basement to connect to the IP DSLAM or PON device and then either leverage the existing copper in the riser or put in new fiber. The more common scenario for existing providers, given the cost to deploy fiber initially into a riser, is to leverage the existing copper via VDSL2 and or ADSL2+ at the last foot in the building.

While Zhone has established itself as a sound provider to independent ILECs and CLECs in the U.S., the vendor continues to gain ground throughout Asia, Canada, Europe, and the Mid-East where MDUs are more common. Since the Zhone products can address MDU/MTUs, it will likely find even greater resonance with international broadband carriers.

“Outside the U.S. market where there’s densities of multi-dwelling and multi-tenant units, we’re seeing a lot of interest from operators in trying to leverage the copper plant that’s in these buildings and drive almost fiber-like bandwidth over the copper plant,” said Mastrangelo. “One way to do that is with these VDSL2 platforms that we have been seeing introduced by a number of vendors across the board.”

The international MTU/MDU broadband trend should not be all that surprising. Whereas the U.S. is made up of a bigger mix of single-family homes, in other countries such as Canada, Asia-Pac and Europe, there’s a greater density of MDU/MTUs. Bell Canada, for example, recently announced that it would extend its FTTN network into new MDU/MTU developments in the Quebec-Windsor corridor.

Bell’s reason to extend FTTN to MDUs/MTUs was to address the growing population of urban dwellers in its regions. “More and more Bell Internet customers in our largest markets are living in condominium developments and other new MDUs,” said Kevin Krull, President of Bell Residential Services in an official announcement about the new service.

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