Oki Electric Develops World's First CDM-on-Fiber, Achieving Bidirectional, Same Wavelength Data Transmission Without Optical Amplifier for a Transmission Distance of Over 100km.

TOKYO -- Oki Electric Industry Co., Ltd. (TOKYO:6703) today announced it has succeeded in developing the world's first next generation broadband access network solution using Oki's Code Division Multiplexing on Fiber (CDM-on-Fiber; COF-PON (1)), offering bidirectional (on same wavelength) data transmission over 100km Single Mode Fiber without an optical amplifier. This new breakthrough enables uplink and downlink signals to use the same wavelength on one optical fiber and to be transmitted over ultra long distance. This will not only be a solution for regional disparities in receiving optical access service, but will also drastically reduce both capital and operating expenditures for service providers.

Broadband access service is shifting from ADSL to higher capacity optical access services to respond to the market demand of video-on-demand (VoD) and higher speed Internet services. Passive optical network (PON) architecture is used for such services and it usually includes three wavelengths for uplink and downlink data. It then divides the signal through a splitter for delivery to each household, providing broadband multimedia service with triple play that enables video, data and voice communication. As demands for higher capacity networks increase, solutions for the "digital divide" problem are needed, and longer distance PON, in U.S. and European regions where network access is difficult, is also required.

"We believe the development of our COF-PON is an important step for enabling high-quality optical service to be provided without any disparity, because it can transmit Multi-Gigabit/s Data Rate up to 100km, much longer than conventional systems. It also offers higher QoS, as it guarantees the bandwidth at all times," said Harushige Sugimoto, Senior Vice President and Chief Technology Officer at Oki Electric. "We will continue to work on matching quality and performance to respond to the market demands for wider optical access services including broadcast service."

To meet the exponential growth of bandwidth demand due to higher speed Internet, triple play, VoD, and to provide services to larger number of customers, Wavelength Division Multiplexing (WDM) for PON systems is attracting attention. WDM-PON require multiple expensive tunable optical sources and wavelength management, and also need expensive optical amplifiers, thus makes it difficult for practical implementation. For data signals, current PON use two wavelengths for uplink and downlink, and the transmission distance is limited to 20km, which prevents the expansion of the range for providing service. While PON systems using optical amplifiers that can expand the area are under review, there are issues as to the amount of power consumption and complexity of optical power management required for the optical amplifiers. Even in this situation, telecom operators have continued to demand more diversification and higher quality in optical services and have been seeking a solution with PON technology that enables simple, low cost, yet long distance and large capacity optical access services.

Oki's newly developed COF-PON system solves these problems. Code Division Multiplexing carried out in electrical domain offers colorless operation. Electrical Code Division Multiplexed signals modulate the laser and converting into optical signals and transmitting over optical fiber. Compared to conventional time division multiplexing, the code process can improve receiver sensitivity, thus enabling provisioning over longer distance without having to make changes in installed optical fibers that or require expensive optical amplifiers. Capitalizing on the feature of enabling longer transmission in a single fiber, Oki guarantees a bandwidth of 100Mbps per channel with bidirectional transmission on same wavelength. Because it uses single wavelength, it is easier to overlay on WDM-PON, doubling the total capacity and expanding to a longer service area.

Samples will be available from December 2006 with a plan of commercial products to be available from 2008 for the optical access market in the U.S. and Europe. Oki Electric will exhibit the COF-PON at the 2006 Optical Fiber Communication Conference & Exposition (OFC:06) (http://www.ofcnfoec.org/) to be held at the Anaheim Convention Center in California from March 5th to March 10th, 2006 (Booth #3447).

Glossary

(1) COF-PON:

This is a system that transmits code division multiplexing signals over optical fiber access networks.

In the transmitter, a digital circuit using a high-speed LSI codes the signal, while at the receiver, the signal is decoded by a super high-speed analog correlator. By using this analog correlator, the limited processing speed of the digital correlator can be overcome and eliminate the need of an expensive A/D converter and Digital Matched Filter at the receiver.

About Oki Electric Industry Co., Ltd.

Founded in 1881, Oki Electric Industry Co., Ltd. is Japan's first telecommunications manufacturer, with its headquarters in Tokyo, Japan. With the corporate vision, "Oki, Network Solutions for a Global Society," Oki provides top-quality products, technologies and solutions to its customers through its info-telecom system business, semiconductor business and printer business. All three businesses function as a collective force to create exciting new products and technologies that satisfy a spectrum of customer needs in various markets. Visit Oki's global web site at http://www.oki.com/.

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