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Mark A. Wegleitner, senior vice president and chief technology officer of Verizon Communications, addresses attendees of the OFC/NFOEC plenary session.
Anticipating the Broadband Revolution:
OPN June 2007 | 37
Patricia Daukantas
Report from OFC/NFOEC 2007
More than ever before, optical communications is about FTTX—bringing fiber to the home, the small business, the rural villages. In Anaheim, 13,000 attendees at OSA’s premier fiber-optics conference learned about the latest advances in super-fast short-haul networks.
Anticipating the Broadband Revolution:
www.osa-opn.org38 | OPN June 2007
roadband communications and last-mile optical cables were two of the hot topics at
the 2007 Optical Fiber Conference/Na-tional Fiber Optic Engineers Conference (OFC/NFOEC). The widespread expec-tation that consumers will soon demand new video, high-speed data and telephone “triple-play” service generated excitement among researchers and vendors alike.
Mark A. Wegleitner, senior vice presi-dent and chief technology officer of Veri-zon Communications, called this decade “the golden age of optics.” His company, which started its first large-scale fiber-to-the-premises (FTTP) project in 2004, is debuting gigabit passive optical network (GPON) technology in selected parts of Texas and Pennsylvania while continuing to roll out its broadband passive optical network (BPON) in other regions of the country. GPON will give customers four times the downstream bandwidth and eight times the upstream bandwidth of BPON.
Wegleitner termed reconfigurable op-tical add/drop multiplexers (ROADMs) a “breakthrough technology,” especially for video services. The company planned to have 500 ROADM nodes deployed by mid-2007.
“Whatever we do has to last about 15 years, because we can’t get back to it in anything less than 15 years,” Wegleitner said. “Otherwise, we’ll be spinning our wheels on reinvestment.” The company’s research into next-generation technolo-gies led to the conclusion that FTTP was the one that can be constantly upgraded to provide more bandwidth without rip-ping up the streets again.
However, Verizon is not ignoring traditional long-haul communications. For example, the company is the single U.S. partner in the Trans-Pacific Express, an 18,000-km link between multiple points in Asia and Nedonna Beach, Ore. At a capacity of 1.2 Tbps initially
While talking to a press gathering at OFC/NFOEC, Bates also provided a bit of perspective: A series of 20-Mbps video streams going into 20 homes is about equal to the total amount of Internet bandwidth available in 1995.
Vik Saxena, senior network architec-ture director for Comcast Cable, a rival of Verizon in the expanding triple-play market, said his company has made a big bet on convergence and is decommis-sioning most of its legacy SONET and focusing on running a unified network to provide all services.
However, cable television, whether provided by coaxial copper or fiber op-tics, may need to guard against a possible “return of the rabbit ears” by the end of this decade. If the Federal Communica-tions Commission is going to mandate over-the-air digital TV for free in 2009, why should customers pay for enhanced service?
The networking executives remain confident that the business model of pay TV will endure, as few cable customers get the bare-bones broadcast-only service, even today. Delivering content from large video libraries could also become impor-tant in the mass market.
Bringing fiber to the home
There’s no doubt that fiber to the home (FTTH) is finally getting off the ground on both sides of the Pacific Rim. Sang-hoon Lee, senior executive vice presi-dent of Korea Telecom, told the annual OFC/NFOEC Service Provider Summit that the company plans to deploy FTTH to 1 million homes this year, despite the saturated market for traditional broad-band service. Panelists followed up with their own strategies for expanding the reach of FTTH.
In Japan, traditional fixed-phone usage is gradually declining with the migration to mobile and IP phones, said Motoyuki
B
and 5.12 Tbps eventually, the optical cable will provide 60 times the current bandwidth between the United States and mainland China. New roots and more capacity are also being added to the Atlantic Mesh Network, and Verizon is developing a new route-control infrastructure for transatlantic cables.
These days, people in the United States take a rich multimedia experience for granted, but it wasn’t that long ago that that was not the case, said Tony Bates, a senior vice president of Cisco Systems Inc. The growth of video-related services, both to computers and to home theaters, is driving the bandwidth hunger.
Whatever we do has to last about 15 years, because we can’t get back to it in anything less than 15 years. Otherwise, we’ll be spinning our wheels on reinvestment.”
— Mark A. Wegleitner, senior vice president and chief technology
officer of Verizon Communications
A series of 20-Mbps video streams going into 20 homes is about equal to the total amount of Internet bandwidth available in 1995.
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Ii, general manager for plant planning at NTT East Corp. Japan now has 7 mil-lion FTTH customers, with 2.7 million new users signing up in 2006, and NTT East’s goal is to have 300 million FTTH subscribers by 2010.
Triple-play (broadband video, data and voice) service costs the equivalent of $56 per month in U.S. currency, Ii said. The company initiates service to custom-ers in seven days for areas of high demand and intensive prior investment and in up to 20 days in low-demand areas where there has been minimal prior investment.
NTT East has worked to shorten the installation time for introducing FTTH into “old buildings,” or multi-family dwellings without FTTH infrastructures, Ii said. The company is replacing mechanical splices with connectors and has introduced optical outlets and free-bending optical fiber cord into individual housing units to enable do-it-yourself setups.
Vincent O’Byrne, technology director of the Verizon Technology Organiza-tion, said his company’s FTTH service, Verizon FiOS, is being deployed in 16 states. It had 3 million customers at the end of 2005 and gained another 3 mil-lion in 2006. The company aims to have 9 million by the end of this year and 18 million by 2011. The penetration rate is running at about 14 percent, compared with 7 percent in 2005.
Verizon FiOS has a standards-based BPON architecture, O’Byrne said. The guiding principles the company used for developing its FTTH network were: no new wires where possible; simple, flexible installation; 100 Mbps or better throughput (the FiOS maximum is 500 Mbps); remote manageability (moni-toring performance and troubleshooting problems without sending out a truck); and open, standards-driven technology. Verizon developed a “broadband home router” that connects the street-level fiber
In the first five years since China joined the World Trade Organiza-tion, the number of mobile phone sub-scribers tripled and the number of Internet users quadrupled.”
— Chongcheng Fan, retired professor at Tsinghua University and vice director of the Chinese Inst. of Communications
broadband infrastructure that already ex-ists in parts of the state, although it has to quell industry’s concerns about propri-etary information.
Broadband in other lands
Plenary speaker Chongcheng (C.C.) Fan, retired professor at Tsinghua University and now a vice director of the Chinese Institute of Communications, noted that in the first five years since China joined the World Trade Organization, the number of mobile phone subscribers tripled and the number of Internet users quadrupled.
Although China’s Internet penetration is about 10 percent, which is still lower than most of the developed countries, broadband users account for nearly 70 percent of the total number of Chinese netizens, with no sign of market satura-tion, Fan said.
During 2006, China deployed 13 mil-lion km of optical fiber, about 60 percent of the U.S. fiber installation for that year, Fan said.
China’s national information technol-ogy strategy through the year 2020 calls for a “Tele-Service to Every Village” proj-ect to link up remote agricultural regions, broadband mobile wireless telecommuni-cations and next-generation optical net-working with automatic switched optical network technology, so-called “fiber to the X” and optical cross-connects.
Tele-Service to Every Village will benefit the more than 800 million Chinese in rural areas, Fan said. The final 1.1 percent of “administrative villages” will get telephone service by the end of 2007, with smaller villages connected by 2010. In one region of the Sichuan province, a voice and data service called the Tianfu Information Network has handled more than 300 million messages and has won a UNESCO World Information Summit Award.
network to either the existing coaxial cable within a customer’s home or to the customer’s wireless network.
How can broadband fiber technologies benefit all customers, rather than just those who live in wealthy neighborhoods? Last year, Gov. Arnold Schwarzenegger issued an executive order to create the California Broadband Task Force to grapple with such issues within the Golden State.
Michael Liang, co-chair of the 19-member task force, said that the group’s goal is to increase adoption among so-called underserved populations in California. Its first task is to map out the
A series of 20-Mbps video streams going into 20 homes is about equal to the total amount of Internet bandwidth available in 1995.
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China has three Internet Protocol television (IPTV) licensees, which are co-operative projects between telecommuni-cations and cable-TV providers, Fan said. Although the country has only 550,000 IPTV subscribers now, their numbers could grow to 5 million to 10 million in three years, Fan said.
In the near term, the existing copper Digital Subscriber Line base has cut back on demand for FTTH, but Fan predicted that Ethernet passive optical network (EPON) will become the technology of choice, especially for high-end residences, business districts and rural networks.
Tech guru Nicholas Negroponte has a high-level vision of networking rural villages: setting up solar-powered Wi-Fi boosters and letting children experiment and learn online. He found that the limiting financial factor is not telecom-munications, but the price of computers, so he’s working to change that with his One Laptop per Child program.
Negroponte, another plenary speaker, told the OFC audience that it’s “crimi-nal” to force kids to learn Microsoft Office when they should be using the computers for more intuitive experimen-tation and play. The program’s laptops will have a simple pictorial interface that encourages collaboration with other users on the network.
One Laptop per Child plans to start mass distribution of the machines and wireless hubs in nine countries this sum-mer, Negroponte said. One potential funding scheme is to have U.S. children purchase similar laptops above cost to, in essence, buy a laptop for another child in a developing nation.
Home fiber for the do-it-yourselferIf telecoms bring fiber to the home, how do customers get it inside the home and hooked up to individual computers and peripherals? Polymer or plastic optical fiber (POF) could work better than glass
LEDs and a 1-mm-diameter fiber can produce 1 Gbps over short distances.
Forty car models, including those in the BMW 6-series, contain POF, and the automobile industry is adding fiber at the rate of more than 10 million nodes per year, Ziemann said. For home networks, error-tolerant 100-Mbps POF is available from various manufacturers.
A.M.J. Koonen from the Eindhoven University of Technology in the Neth-erlands presented a scheme for in-home networking with a thick-core POF backbone for both wired and wireless communications. He and his colleagues used low-cost 64-QAM (quadrature am-plitude modulation) chip sets to optimize bandwidth consumption and the link power budget.
Light sources and fibers
Researchers at two New Jersey companies have developed a new distributed light source, based on fiber Bragg gratings, that can be used for line-scan sensing. The team from Princeton Lightwave Inc. and OFS Labs took light from a fiber-coupled source and sent it through a 45-degree-blazed fiber grating and a cylindrical collimating element.
The light source was designed to dis-tribute significant, uniform power density over a rectangular region, which is a re-quirement for line-scan sensing. This type of light source could be used in many types of industrial inspection systems.
In addition to fibers, lasers are an important part of photonic communica-tions systems.
For instance, large-scale terawatt and petawatt laser systems have substantially different requirements from telecom systems, said John R. Marciante of the University of Rochester. Such systems require high-gain fibers, careful control of temporal pulse shape, linear polarization, synchronized pulses, minimal propaga-tion in media, and narrowband, phase-
Tech guru Nicholas Negroponte has a high-level vision of networking rural villages: setting up solar-powered Wi-Fi boosters and letting children experiment and learn online.
fiber in networks inside homes and small offices.
POF can tolerate a shorter bending radius than large-diameter glass fibers, and the cables are tough and flexible, said Olaf Ziemann of the POF Application Center at the University of Nuernberg, Germany. POF cables are unaffected by electromagnetic interference and are tough and easy to manufacture and con-nect.
Over short distances, POF systems can use low-cost LEDs instead of lasers, Ziemann said. The combination of blue
Polymer or plastic optical fiber could work better than glass fiber in networks inside homes and small offices.
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[ References and Resources ]
>> OFC/NFOEC 2007 Technical Digest, Papers OMF6, OMR3, OMR4, OMR6, OTuF5, OThG4 and OThP1, and OFC/NFOEC 2007 Postdeadline Paper PDP19.
>> J.W. Nicholson and M. Andrejco. “A polar-ization maintaining, dispersion managed, femtosecond figure-eight fiber laser,” Opt. Express 14, 8160 (2006).
>> Paul Polishuk. “Plastic Optical Fiber Builds on MOST Success,” Laser Focus World 42(3), 57 (2006).
>> Varun Raghunathan et al. “Self-imaging silicon Raman amplifier,” Opt. Express 15, 3396 (2007).
modulated signals. In fact, the only thing laser-fusion systems have in common with telecommunication systems is the need for reliability.
The Omega system at the Rochester Laboratory for Laser Energetics is seeded with a single-frequency distributed-feed-back fiber laser. That commercial fiber laser provides the polarized cw (continu-ous wave) seed light from which pulses are carved, Marciante said.
High-contrast, single-shot pulse shape measurements are required for laser fusion experiments, Marciante said. Averaging replicated pulses can produce the benefits of averaging while retaining single-shot events, and passive all-fiber systems enable precision measurements.
Fiber technologies could have other roles in laser fusion labs, such as UV optical-signal delivery, mid-IR optical power delivery, and mechanical structures that do not absorb 3-µm radiation, Marciante said. Active fiber systems provide high-gain, low-noise, polarization-preserving amplification, and passive all-fiber systems enable precision measurements.
Femtosecond fiber lasers are approach-ing bulk solid-state lasers in performance, said Jeff Nicholson of OFS Laboratories of Somerset, N.J. Applications of these lasers include communications, biomedi-cal optics and frequency combs.
The first fiber lasers operated in the soliton regime. Nicholson traced their development through erbium- and yt-terbium-doped lasers in the 1990s. New operating regimes in the last few years include similariton lasers, which generate pulses that maintain their temporal shape (parabolic), but not width, during propa-gation. These lasers’ pulses are always highly chirped.
With an output of 700 mW, the wave-breaking free erbium laser, developed in 2005, is approaching solid-state lasers in performance, Nicholson said. He and colleague M. Andrejco last year demon-
came from Pacific Rim nations, includ-ing Australia and New Zealand, reported Lynn Nelson of AT&T Laboratories, one of the event’s general chairs. Another 23 percent came from Europe, includ-ing Russia, while 31 percent originated in North America. Sixty percent of the 975 papers submitted to the combined conferences were accepted.
A total of 47 papers were accepted for the five postdeadline sessions in 2007. Headlining this year’s crop of results was the announcement of a record-breaking 25.6-Tbps data transmission over a single strand of fiber. The American-French-Japanese research team headed by Alcatel-Lucent used 160 wavelength-division-multiplexed channels, each containing two co-polarized signals in return-to-zero format. The researchers made use of differential quadrature phase-shift keying for greater bandwidth efficiency.
In February 2008, OFC/NFOEC moves southward along the California coast to San Diego. New developments in FTTX networks, silicon photonics, high-bandwidth optical communications and other fiber-related topics will doubtless dazzle next year’s attendees. t
[ Patricia Daukantas ([email protected]) is the senior writer/editor of Optics & Photonics News. ]
strated a polarization-maintaining figure-eight ytterbium fiber laser, which was modelocked by a nonlinear loop mirror.
Developments in high-performance computing
Another area in which high-bandwidth fiber systems are making an impact is high-performance computing (HPC).
Ethernet has been dominant in the data center, where the typical architecture of an HPC server cluster consists of eight cabinets and two switches, said Peter Pepeljugoski, an IBM Corp. researcher. However, the ever-increasing demands of interprocessor communication and multi-core CPUs are exceeding the limits of 10-Gbps Ethernet, and optical fibers could remove these bottlenecks within supercomputer clusters.
“For distances of less than 100 m, we believe the future belongs to optics,” Pepeljugoski said. Fiber avoids the bulk, weight, power-consumption and cool-ing problems associated with traditional copper cabling. He predicted that the HPC market will switch to 100-Gigabit Ethernet optical interconnects over the next few years, and fiber will be an HPC workhorse for many years to come.
Optical researchers are also paying at-tention to the interconnect bandwidth re-quirements within the same circuit board or through backplanes connecting circuit boards in HPC systems. Another IBM team, led by Clint L. Schow, has built a 160-Gbps, 16-channel CMOS optical transceiver on a single chip. The trans-ceiver module, reported to be the fastest such device, incorporates 4 3 4 arrays of high-speed photodiodes and vertical-cavity surface-emitting lasers (VCSELs), both operating at 985 nm.
A truly global conference
This year’s OFC/NFOEC was truly international. Forty-two percent of the contributed papers to OFC/NFOEC
Polymer or plastic optical fiber could work better than glass fiber in networks inside homes and small offices.
