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Achieving the Core Prototype of Spectrum sharing Wireless Communications System

- Using Open Frequencies through Harmonizing Cognitive Radio Base Stations and Cognitive Radio Terminals -

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May 7, 2009

The National Institute of Information and Communications Technology (NICT; Dr. Hideo MIYAHARA, President) has developed a prototypical device of a wireless communications system based on spectrum sharing cognitive radio technology. Spectrum sharing cognitive radio technology is a technology for achieving cognitive wireless networks, and is garnering attention as a technology for more effectively utilizing radio resources under today’s tight frequency use.


More effective and efficient use of radio wave resources is required to enable faster, higher capacity, higher quality wireless communications in today’s tight radio wave use conditions. Cognitive radio is attracting attention as a technology to realize such wireless communications. Cognitive radio technology is classified into heterogeneous and Spectrum sharing technologies. NICT has promoted research and development of these two technologies, achieving a core prototype for an advanced Spectrum sharing wireless communications system.


NICT created a core prototype of a Spectrum sharing wireless communications system integrating cognitive radio base stations, cognitive radio terminals and network reconfiguration managers. Cognitive radio base stations automatically select frequencies that other systems do not use for operations. Communications via a cognitive radio base station are possible with a cognitive radio terminal because of the reconfiguration to a frequency band in operation notified from the network reconfiguration manager. This system enables frequency bands not used temporally or interstitially to be harmoniously used by multiple systems. In addition, this system was developed under a contract of R&D for radio resource enhancement, organized by the Ministry of Internal Affairs and Communications, Japan.

Future Goals

Further miniaturization and additional functions will occur hereafter for real-world use of this system. This will also contribute to the establishment of IEEE 1900.4.1, IEEE 1900.4a and other global standards based on the prototype system specifications.

Terminology & Interpretations

Cognitive Wireless Network
A cognitive wireless network is a wireless access network using cognitive radio technology possessing features for selecting the radio access and network path suited to radio use conditions such as little interference from recognized usable wireless systems. The cognitive wireless network has two approaches based on “heterogeneous cognitive radio technology” and “spectrum sharing cognitive radio technology” as shown in the figure.

Cognitive radio Technology
Cognitive radio technology is a wireless communications technology for transmitting, continuously working on efficient frequency use at a communications quality users require be at a desired communications size through the wireless device recognizing the radio wave environment, and the proper use of frequency bandwidth, timeslots and other wireless resources without interfering with other systems according to these conditions.


— Prototype System Schematic Diagram —
— Prototype System Schematic Diagram —

Technical Contact

Hiroshi HARADA, Group Leader /
Kentaro ISHIZU, Expert Researcher
Ubiquitous Mobile Communications Group
New Generation Wireless
Communications Research Center
Tel :+81-46-847-5098

Public Relations

Sachiko HIROTA
Public Relations Office
Strategic Planning Department