Research and development on advanced spectrum sharing systems using wide-area WRAN system

Kyoto University, Hitachi Kokusai Electric Inc.
Principal Investigator: Keiichi Mizutani


Public institutions such as police and fire departments have been introducing Wireless Regional Area Network (WRAN), a VHF broadband mobile communication system that complies with the ARIB STD-T103 standard. The use of this system has enabled broadband communications, including moving image transmission, in self-employed public communications. Still, there will be a need for even higher capacity moving image transmission to cope with unprecedented disasters in the future. Therefore, it is expected that public users will also use the current VHF wide-area WRAN as well as 5G, which is currently gaining momentum for full-scale operation. However, the number of frequencies that can be allocated to new wireless communication systems is running out, and there is an urgent need to improve frequency utilization efficiency more than ever before. Under these circumstances, a full-scale practical application study of a spectrum sharing system, in which heterogeneous systems share spectrum resources, has been promoted. The aim of this research and development is to realize a highly efficient spectrum sharing system using a VHF-band WRAN system.

Key points

In this research and development, using the propagation and transmission characteristics of VHF wide-area WRANs, we will establish a technology to predict and avoid interference in other frequency bands, such as Sub6GHz, and to realize highly efficient spectrum sharing.


Keiichi Mizutani
Kyoto University
Principal Investigator

Hiroshi Harada Kyoto University
Masayuki Ishizaki Hitachi Kokusai Electric Inc. Chief Investigator
Kiyoshi Yamamoto Hitachi Kokusai Electric Inc.
Masahiro Asano Hitachi Kokusai Electric Inc.


[International Conference Papers]

  1. T. Hayashida, R. Okumura, K. Mizutani, and H. Harada, “Possibility of Dynamic Spectrum Sharing System by VHF-band Radio Sensor and Machine Learning,” Proc. IEEE DySPAN 2019 Workshop on DD-DSS, pp. 1–6, Nov. 2019.

[Domestic Conference Papers]

  1. T. Hayashida, K. Mizutani, and H. Harada, “An Outdoor Position Estimation by Machine Learning with Delay Profiles Measured in Urban Area,” IEICE General Conference 2020, B-18-6, Mar. 2020.
  2. K. Yanagisawa, T. Abe, M. Ishizaki, M. Asano, K. Mizutani, and H. Harada, “High-speed Reception Gain Control Method for Synchronization Signal Analysis of VHF-band Broadband Mobile Communication System,” IEICE General Conference 2020, B-18-5, Mar. 2020.
  3. K. Mizutani and H. Harada, “[Requested Talk] Terminal Position Estimation Using Delay Profile and Machine Learning,” IEICE SRW, SRW2019-82, pp. 111–116, Mar. 2020.
  4. T. Hayashida, K. Mizutani, H. Harada, “Position Estimation of User Equipment Using VHF-band Delay Profile in Urban area and Machine Learning,” IEICE SRW, SRW2019-71, pp. 57–62, Mar. 2020.