OKI Develops Japan's First 920MHz Frequency Band Wireless Multi-hop Communication System for Smart Communities

TOKYO--(BUSINESS WIRE)--OKI today announced that it has succeeded in the development of Japan's first wireless multi-hop communication system for the new 920 MHz frequency band¹ which is scheduled to open by the Ministry of Internal Affairs and Communications in July 2012. The 920 MHz band offers high signal propagation and considerable promise for wireless multi-hop communication² technologies ideally suited for use in smart communities, smart houses and smart meters.

Smart grids that use information communication technologies for energy management such as electricity have attracted significant interest, and studies continue on smart communities capable of deploying such management control and smart houses that make effective use of green energy.

"Making smart communities and smart houses a reality requires a communications infrastructure to transmit data, such as electricity control data. The communications infrastructure will require home networks that connect home appliances and electrical power equipment within the home or office, and field area networks that connect devices such as smart meters between outside buildings," says Takeshi Kamijoh, General Manager of Research and Development Center at OKI. "Wireless multi-hop communications are expected to make such infrastructures possible. Electrical power equipment such as smart taps and smart meters are often installed in locations with poor signal access, underscoring the significance of the 920 MHz band with its high signal propagation compared with 2.4 GHz which broke communications."

OKI has developed an IEEE 802.15.4³-compliant wireless multi-hop communications system to accommodate conditions of use for the new 920 MHz frequency band currently being deliberated on by the Ministry of Internal Affairs and Communications, and OKI evaluated performance using an acquired experimental transmitter. The testing confirmed that communication is possible over 10km when transmission output of 250mW, the specified maximum. The testing also confirmed direct communications in urban locations among many obstacles such as buildings at a transmission output of 70mW within an area of approximately 150m in radius.

Moving forward, OKI will play a major role in promoting widespread use of smart communities, smart houses and smart meters based on 920 MHz wireless multi-hop technology. By applying this technology to a wide range of new services, OKI will also try to realize a society in which people feel more comfortable, safer, and secure. In addition to incorporating this technology into commercial products, OKI will draft plans for the ZigBee³ standards that support 920 MHz for smart houses to familiarize ZigBee standards which is recognized internationally, and will also continue working to strengthen interconnectivity for home appliances, electrical power equipment, and home gateways.

The achievements to date will be presented at the Institute of Electronics, Information and Communication Engineers Society Conference to be held at Hokkaido University on September 14.

[Glossary]
*1	920 MHz frequency band
Encompassing frequencies between 915.9 MHz and 929.7 MHz in Japan, this frequency band is widely used outside Japan for applications such as smart meters, due to high signal propagation compared to the 2.4 GHz band generally used for sensor networks.
While the 950 MHz band has been in use in Japan since the band was institutionalized in 2008, the shift to the 920 MHz band is expected to stimulate the market through international partnerships, since the same frequency band is used in the United States and Asia. The 920 MHz band also permits higher transmission output (20 mW or 250 mW) than the previous 10 mW limit.
*2	Wireless multi-hop communication
Wireless multi-hop communication refers to data transmission involving other wireless devices by a "bucket brigade" process. It is widely used in sensor networks due to its capacity to function without communications infrastructure elements such as base stations.
*3	ZigBee, IEEE 802.15.4
Wireless multi-hop communications such as sensor networks generally comply with IEEE 802.15.4 international standards for wireless communications and ZigBee for network communications. Implemented as a standard in 2009 following deliberations headed mainly by OKI, IEEE 802.15.4 includes a physical layer extension known as IEEE 802.15.4d that supports the Japanese 950 MHz band.

About OKI Electric Industry (OKI)
Founded in 1881, OKI Electric Industry is Japan's leading telecommunications manufacturer. Headquartered in Tokyo, Japan, OKI provides top-quality products, technologies, and solutions to customers through its info-telecom systems and printer operations. Its various business divisions function synergistically to bring to market exciting new products and technologies that meet a wide range of customer needs in various sectors. Visit OKI's global website at http://www.oki.com/.

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