Passive Optical LANs bring a track record of outside-plant success.
by Patrick McLaughlin
The recent deployment of an all-optical local area network (LAN) at Stony Brook University in New York reflects what could become a trend of technologies developed for longer-haul metropolitan area networks (MANs) and wide area networks (WANs) being deployed in enterprise environments.
Motorola (www.motorola.com) was the lead vendor in terms of publicizing the Stony Brook installation. But two other providers, one ubiquitous in the service provider space and another very familiar to both outside-plant and LAN professionals, played significant roles in the Stony Brook project. Verizon Business (www.verizonbusiness.com) and ADC (www.adc.com) were instrumental in the deployment and ADC reports that Stony Brook is one of several users choosing to implement an all-optical LAN.
Motorola dubs the system Passive Optical LAN (POL) and had this to say about the technology: “Motorola’s POL solution provides a great option for enterprises interested in significant capital and operational cost savings propelled by a greater than 50 percent in five-year total cost of ownership over today’s traditional LAN architectures, including more than 70 percent savings in the cost of service agreements and 40 percent in energy savings.” Those savings estimates are based on Motorola’s POL being deployed in a three-story building with a total of 1,080 users, each with one voice and one Ethernet data port, and ubiquitous access to a Power over Ethernet (PoE)-connected wireless LAN.
“Motorola’s POL solution offers a compelling case to those looking to achieve IT savings while expanding and simplifying their network,” according to Joe Cozzolino, senior vice president and general manager for Motorola Mobile Devices and Home. “We are pleased to include our innovative POL solution in CEWIT’s advanced educational and research center.”
CEWIT stands for the Center of Excellence in Wireless and Information Technology, which is the Stony Brook facility at which the POL was deployed. Established in 2003, CEWIT is a partnership between the State of New York and industry-leading businesses, Motorola explains. Its new facility at the Stony Brook University Research and Development Park provides researchers with 100,000 square feet of additional lab space.
From carrier to enterprise
In March 2010 ADC announced a partnership with Verizon Business in which the two organizations are offering all-optical LAN systems to federal customers in the United States. Verizon Business uses slightly different nomenclature than Motorola, calling the system it provides an Optical LAN Solution (OLS).
Products including ADC’s Rapid Fiber system portfolio, its TrueNet cabling solutions and its RealFlex products are part of the Verizon Business offering.
At that time ADC described the system and its technology as follows. “The OLS, which takes converged services all the way to the desktop, uses the same passive optical network (PON) technology and practices that go into Verizon’s nationwide fiber-to-the-premises network. The OLS network’s Gigabit PON (GPON) architecture means it can deliver full Gigabit Ethernet service to each desktop and, with GPON’s sophisticated data-encryption capabilities, provide the secure transport of information between users.
ADC’s president of global connectivity solutions Pat O’Brien describes the fit of his company’s systems into the OLS suite. “When Verizon Business came to us looking for next-generation fiber infrastructure to support its OLS solution for its federal customers, key issues were cost, speed of installation and quality. It also needed to manage cable volumes easily and conserve space in the process. Our fiber equipment helped Verizon Business address these issues and provide a completely passive end-to-end green solution that enables customers to significantly reduce power consumption and cooling costs of operating the network.”
Adds Ed Hill, director of program management for Verizon Business, “Our federal customers can see for themselves why our OLS offering is a true green solution that is secure, scalable and can meet the needs of their future networks. We want our customers to understand how this solution can help their agencies improve network efficiencies, enhance network capacity and reduce capital costs.”
What is likely to be the most-foreign concept of the OLS/POL architecture for network managers within end-user organizations is that it uses singlemode fiber all the way to the desktop. Verizon Business and ADC tout the fact that such a system theoretically can provide data rates up to 25 terabits per second, Voice over Internet Protocol, and 2,000 video channel at distances up to 12 miles over a single fiber strand. But running singlemode fiber to the desk? How realistic is that for today’s network manager? And how can it be labeled cost-effective when everyone in the cabling industry has heard time and time again that long-wavelength optical transmission over singlemode fiber is the most expensive option, head-and-shoulders above short-wave optical transmission via multimode fiber and dwarfing electrical transmission over twisted-pair media?
Green equals green
ADC business development manager Bryan Kennedy explains that the idea is not so far-fetched when building space, campus environments, total cost of ownership and energy costs are factored in. “Initially we saw interest in the government space because of the security of the GPON system. But it’s also good for colleges and universities. One reason is how attractive it is in campus environments, or even in a multiple-floor single building.
“Workgroup switches on each floor support horizontal cabling,” Kennedy explains. “The 100-meter limit has lent itself to multiple closets on a floor, with workgroup switch electronics supporting users. It’s complicated, but it’s a network we’ve gotten used to over the years.
“When you have a multi-building environment, you multiply that complexity. In an optical LAN GPON, a system has a 20-kilometer reach from optical line terminal to optical network terminal.
“The green aspects of it are unbelievable,” Kennedy adds. “We’ve seen nothing yet that’s a drawback in that regard. For example, a customer that is used to dealing with traditional LAN architectures will see significant energy savings. A 700-user system can save up to $100,000 a year in energy cost. That’s year-over-year savings and is pretty dramatic.”
He says that it took some users time to warm up to the idea. Those who have always implemented traditional LAN architectures “were skeptical,” he states. Specifically with regard to the high costs of a long-wavelength singlemode-based LAN he notes, “Costs are making it more attractive. Users are able to do more things than ever before. They can run a POTS line and Power over Ethernet. In some cases it would take four horizontal multimode runs to do the job of one singlemode run.
“You have to look at total cost of ownership,” he asserts. “As an example, if you’re using GPON today someday you’ll have WDMPON [wavelength division multiplexing PON]. For OLS users, their infrastructure is in place for that with singlemode to the desktop.”
While savings on energy costs can be six-figure dramatic, Kennedy says other environmental-impact characteristics favor the OLS as well. “Cable weight and buildup is one consideration. A network with 144 multimode fiber strands and Category 5 twisted-pair cabling for voice connectivity is looking at 884 pounds of cable based on 55-meter runs. Compare that to a singlemode optical LAN, which has 182 pounds of cable,” for the same number of 55-meter runs, he says.
“There are space savings too. Two hundred fifty users in a closet requires 150 square feet. With an optical LAN, you need 12 square feet. There’s also HVAC and UPS impact.” All these factors translate to both space and energy-consumption benefits when using the all-optical singlemode LAN within a building or campus.
PON’s telco heritage
Passive optical networks traditionally have been deployed in carrier or service-provider-type networks as opposed to customer-owned LAN environments, for many of the reasons described already. Kennedy provides a quick history lesson in the technology and how it evolved as a service-provider technology.
“Early work on PON architectures started in the 1990s. The ITU [International Telecommunication Union] developed the APON standard, which stood for Asynchronous Transfer Mode PON. A lot of carriers have deployed fiber-to-the-node for some time, pushing fiber deeper into the network. As fiber increases and prices come down, it is more worthwhile.”
Verizon’s FiOS program, Kennedy points out, originated as a Broadband PON (BPON) system before quickly changing to GPON, both of which are also standards set by the ITU.
“In the carrier space we have seen the PON architecture used primarily by vertically integrated carriers providing triple play,” he continues. “Contrast that with the LAN, which has primarily been data. But now LANs are carrying VoIP and in some cases video services. It’s a natural progression.
“The value that the technology brings to the LAN space is futureproofing, or the ability to easily upgrade. It also provides lower operational maintenance costs.
“When we look at an existing LAN, we traditionally have to replace the infrastructure every 10 to 15 years to keep up with advancements in active electronics. One of the big impacts we see that PON point-to-multipoint has in the LAN is the infrastructure is put in one time. The actives can be upgraded without having to update the infrastructure.”
Real-world installations
In addition to the CEWIT project at Stony Brook University, Verizon Business and ADC have publicized two other OLS installations, one of which was at a Verizon Business office with 500 users and the other at a Washington D.C.-area government facility housing 800 users with three networks: classified, unclassified, and a spare network.
According to Michael Watts, Verizon Business implementation manager, “With the help of ADC’s Professional Services Group, both projects went off without a hitch. We did not have a single fiber port test outside of the standards. So with the combined focus of Verizon Business and ADC, we were able to meet our installation dates, with one project finishing ahead of schedule, due to the reduction of labor hours required.”
The labor-hour reduction was achieved because the projects incorporated ADC’s Rapid Fiber system, which included the space-saving Rapid indoor Fiber Distribution Hub (iFDH), an inside-plant cabinet that functions as the main distribution and crossconnect point for the building. The boxes, which can be wall-mounted, are another example of technology originally developed for outside-plant applications being used inside enterprise buildings.
Passive Optical LAN implementations, which bring singlemode fiber all the way to the user, may be few and far between today. But from a total-cost-of-ownership standpoint, they very well may merit a closer look by user organizations conducting long-term technology and financial planning.
Patrick McLaughlin is our chief editor.