Ethernet Meets PON

With costs for optical components declining and bandwidth demands soaring, PON has reemerged in recent months as a potentially commercially deployable technology. (see How it works).

Indeed, Ross Ireland, senior vice president of services and chief technology officer at SBC Communications Inc. (www.sbc.com) during his speech in May at Networld+Interop said that PON has matured more quickly than the company anticipated, and that SBC plans to bring PON to 150 customers in Houston shortly, to 1,000 customers by the end of the year and to 9,000 customers next year.

But most of the PON solutions available to date have been ATM-based products from companies such as Paceon Corp. (www.paceon.com), a Mitsubishi Electric Co., with which SBC has been working on PON; Quantum Bridge Communications Inc. (www.quantumbridge.com); Terawave Communications (www.terawave.com); and Optical Solutions Inc. (www. opticalsolutions.com).

Now there's talk about Ethernet-based PON solutions from companies such as Alloptic Inc. (www.alloptic.com) and Salira Optical Systems Inc. (www.salira.com). This evolution makes sense in light of Ethernet catching fire in the access portions of public networks and the anticipated eventual migration from ATM to IP networking.

In May, Alloptic announced it is conducting field trials with 23 carriers and service providers spanning every major world market. The implementation of Alloptic's IP Ethernet Passive Optical Network solution in these trials represents a paradigm shift in PON technology by addressing the bandwidth deficiencies, high cost and inability to converge voice, video and data, inherent in access networks utilizing first generation APON (ATM PON) solutions, according to the vendor.

Burnie Atterbury, senior director of product marketing at Alloptic, says bandwidth is the company's key differentiator from other PON solutions. The vendor incorporates burst-mode optical transceiver technology, which delivers between three and eight times the bandwidth provided by first-generation ATM PON systems. Alloptic systems deliver 1gbps downstream and 800mbps upstream bandwidth, while products from APON leaders Quantum Bridge and Terawave deliver just 622mbps downstream and 155mbps upstream, according to Atterbury.

In addition to the bandwidth it can deliver, Alloptic went with EPON over APON because of the economies of scale Ethernet equipment delivers, says Atterbury, noting that Ethernet accounts for about 90 percent of the network interface cards installed today.

As far as PON itself is concerned, Atterbury says that fiber is less expensive to deploy and maintain than copper if it can be installed aerially or in existing ducts because PON means there are no active components--such as amplifiers--to maintain.

Alloptic has fiber-to-the-business, fiber-to-the-curb and fiber-to-the-home products in the pipeline. Release 1 of the FTTB and FTTC versions, including CO and optical network unit remote terminals, were expected to be generally available in June 2001. A FTTH iniative was Pirelli Cavie Sistem SoA (www.pirelli.com) was announced at SUPERCOMM last month.

"We see the market initially as an FTTB play," he says. "FTTH longer term, but shorter term for greenfield."

A fully-loaded Alloptic system with one main fiber and 16 distributed fibers has a list price of $5,600 per subscriber.

Scientific-Atlanta Inc. (www.scientificatlanta.com) is working with Alloptic and Luminous Networks (www.luminous.com), in which Scientific-Atlanta holds equity, to evaluate EPON as a way to modify DOCSIS, a CableLabs spec for offering high-speed data over two-way hybrid fiber/coax cable TV infrastructure, to run over deep fiber access, says Tony Stanley, director of business development at Scientific-Atlanta.

"Ethernet is the largest installed base of any device globally," says Stanley. "It's my view that the simplest way to transport this data over the network is with the Ethernet standard. We see Ethernet passive optical network systems being the next generation to the current systems. The question really is one of timing and commercial viability. It's fair to say that Ethernet and fiber to the home have been around for 10 years or so and haven't reached any significant deployment" because of the lack of product availability and cost issues.

Scientific-Atlanta (www.sciatl.com) has an advanced access lab in Atlanta where it has shown consultants prototype EPON products, and the company is demonstrating EPON to its top customers as well, Stanley says. He also reports that the company expects to do technical trials with customers later this year. Scientific-Atlanta believes small businesses will be the early target of such products.

Another company coming to the EPON space is Salira Optical Systems Inc. (www.salira.com), which announced its corporate launch May 23. The company will announce its products in 2002.

"We're delivering voice, video and data services using the IP protocol, Ethernet framed at user speeds starting at 4mbps and going to 40mbps," says Herb Martin, Salira's president and CEO. "We have the economics to go to the residence at $400 a user for the carrier."

Martin says the IEEE in November 2000 started the 802.3 working group, which addresses EPON. CTO Wei Gao adds there's lots of interest from carriers in EPON, mentioning such companies as BellSouth Corp. (www.bellsouth.com), Qwest Communications International Inc. (www.qwest.com), SBC and Verizon Communications Inc. (www.verizon.com).

Carriers are saying APON and EPON will both be part of their access architectures, says Martin. "But we think EPON will be more widespread," he says. "We're looking at $400 and [APON vendors] are looking at $4,000" per subscriber.

Martin says EPON is useful in delivering bandwidth over long stretches between the CO and the end user. "We'll go 20km, which is 16 miles," he says. "We can cascade to go further." Like others in the EPON space, Martin adds that Ethernet is cost-effective because it's so widely deployed. Ethernet chipsets and other components are cheap. Martin also notes that there's a 622mbps bandwidth cap on ATM while Salira will start at 1.25 to 10gbps with its products. "So number subscribers you can support on the headend equipment is more," he says. "Also, Ethernet has less overhead [than ATM], and Ethernet is very easy to provision."

PON ECONOMICS FOR FIBER TO THE BUILDING (AERIAL PLANT)

U.S. RESIDENTIAL PON MARKET FORECAST

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