TOKYO -- Oki Electric Industry Co., Ltd. (TSE: 6703) today announced that the company has succeeded in developing a new optical encoder/decoder for optical code division multiplexing (OCDM). The device is the world's first encoder/decoder with a dispersion compensation function, offering transmission capacity of up to 10Gbps in bandwidth for bi-directional real-time communications covering a distance of over 40km using single mode fiber (SMF). Compared with conventional devices, this product is more compact in size as it does not require dispersion compensating fiber. The device is suitable for large-capacity data transmission such as hundreds of channels of video content delivery. Oki will present this at the 2004 Optical Fiber Communication Conference and Exposition to be held from February 22 to 27 at the Los Angeles Convention Center.

The OCDM encoder/decoder developed by Oki is based on a Time-Spread/Wavelength-Hop (TS-WH) encoding/decoding method using Fiber Bragg Grating (FBG) technology. While improving the reflection characteristics of the FBG component, Oki also built in a sophisticated dispersion compensation function in the OCDM encoder/decoder device, the first of its kind in the world. This function enables the device to compensate for the chromatic dispersion in SMF, which causes time discrepancy in optical signals, and to extend the transmission distance from 10km to over 40km for the existing metro networks.

The OCDM technology Oki uses for the encoder/decoder offers flexible routing in a large-scale optical network. This technology allocates arbitrary numbers of signal channels to wavelengths by appropriately combining wavelengths and optical coding scheme. It realizes a simpler and more economical network management compared to the conventional wavelength division multiplexing (WDM) networks, which limit the number of signal channels according to the number of wavelengths.

As the demand for broadband services such as video content delivery grows, large-capacity transmissions up to 10Gbps over distances of 40km to 80km are required in metro networks. In order to enable a video-content delivery service that simultaneously offers several hundreds of channels, each of which requires 6Mbps to 30Mbps of bandwidth, a 10Gbps transmission capacity is needed. Oki's encoder/decoder device is suitable for such large-capacity data transmission.

"By introducing Oki's OCDM encoder/decoder to metro networks, users can implement flexible and high-capacity optical signal links," said Harushige Sugimoto, General Manager of the Corporate Research and Development Center at Oki Electric. "10Gbps bandwidth is wide enough to transmit hundreds of video channels. Customers will be able to enjoy multiple services simultaneously, involving video, voices, and data in a real broadband environment. I believe that our new device will drastically help expand the optical communications market."

Oki Electric Industry Co. Ltd.