Akira Sugiura gives a brief history (in English) of Japan's license-exempt radio regulations in "Progress of EMC regulations in Japan and a look to the future," presented at the 5th Forum of the Voluntary Control Council for Interference by Information Technology Equipment (28 October 2005). He says regulations for license-exempt radio were established in 1950. Based on FCC rules, field strengths were limited to 15 μV/m at a distance of λ/2π (wavelength divided by 2 times pi). In 1957, the emission limit changed to 15 μV/m at a distance of 100m. In 1986, it changed again, to 500 μV/m at 3m for frequencies of 322 MHz or less, and 35 μV/m at 3m for frequencies greater than 322 MHz.
主要国における免許不要制度の概要 (Summary of the major powers' radio license exemption systems) by Takao Yamakura, 5 October 2006 in Japanese. See also コグニティブ無線と米国電波政策 (Cognitive Radio and US spectrum policy) by Eiichi Sagawa, 31 August 2006, in Japanese. Both authors work at the Research Institute of Telecommunications and Economics.
Kashiwa FX886 is Yasuo Kagaya's "low-power radio equipment utilisation research & development laboratory" in Tokyo. Like the Open Spectrum Foundation, he collects laws and regulations for license exempt radio from around the world, studies their impact on propagation, range, utility, etc., and how they compare to Japan's rules. Thus, his website is a rich collection of material - mostly in Japanese.
"Japan embraces femtocells, but regulation needs to change," by Mary Lennighan, Total Telecom, 1 June 2010: "...KDDI plans to provide free femtocells to its subscribers. This partly stems from the regulatory regime in Japan, where restrictions state that since femtocells operate in licensed spectrum, they must be deployed by the operator; the consumer cannot go out and buy a plug-and-play product... However, 'that's a uniquely Japanese regulatory concern... That restriction will soon be removed," [Dave Nowicki, vice president of product management at KDDI] predicted..."
"...With regard to wireless systems for joint use such as high-output outdoor wireless LAN, the MIC [Ministry of Internal Affairs and Communication] implemented deregulation and introduced a post-check registration system in place of the existing pre-check licensing system, while maintaining the spectrum order. With the introduction of the registration system, it becomes possible to register radio stations with the same mode of use in a batch while radio stations had to be individually licensed based on detailed information in the past. In addition, individual radio stations can be freely established based on registration (reporting detailed information ex post facto). In this manner, this revision will dramatically expedite and simplify the procedure for opening a radio station, and is expected to promote free use of radio spectrums..." ---from the 2005 edition of MIC's annual white paper on Information and Communication in Japan (in English).
総務省の電波開放戦略「2005年には5GHz帯を拡張して屋外利用可能に」(Expanding access to the 5 GHz band beyond what is already available is in the Frequency Open Strategy 2005 of the MIC), Broadband Watch, 13 October 2004:
講演のタイトルに使われている「電波開放」という言葉は、「新しい電波ビジネスを育成するとともに世界最先端のワイヤレスブロードバンド環境を構築するために大量の電波を開放していく」という総務省の戦略を端的に表わすキャッチフレーズだという。炭田氏は「2003年末頃からこの言葉を使い始めてきたが、今では公的用語として使っている」とコメント、この電波開放の主役となるのが携帯電話であり、無線LANであるとした。 (In title of this lecture by Hiroshi Asami you may note the catch phrase "open frequency" which reveals the strategy of the Ministry of Internal Affairs and Communications: "As new wireless businesses grow, [the ministry] keeps opening spectrum for the public in order to construct a world-leading wireless broadband environment. We started using this phrase [open frequency strategy] around the end of 2003, but now you can use it as public terminology." Leading this opening of the spectrum are the cordless telephone and the wireless LAN...)
コモンズとしての電波コモンズとしての (The Spectrum as a Commons: Digital Wireless Technologies and Radio Policy), by Nobuo Ikeda, RIETI Discussion Paper Series 01-J-005, 2002, in Japanese.
ブロードバンド時代の制度設計 II - Materials from a workshop on spectrum reform and Open Spectrum at the Research Institute of Economy, Trade and Industry (RIETI), 4 December 2003, in Japanese and English. Panelists were Nobuo Ikeda, RIETI Senior Fellow and moderator; Yoshiyuki Takeda, Director of the Radio Department, Japanese Ministry of Post & Telecommunications; Robert Pepper, Chief of Policy Development, US Federal Communications Commission; Lawrence Lessig, Stanford Law School; Peter Pitsch, Director of Communications Policy, Intel Corp.; and Yoshihiro Tanaka, President of FuuUn & Rivals, Ltd.
English-language outline of the Telecommunications Council report Radio
Policy Vision: Guidelines for Spectrum Re-allocation (30 July 2003). Among other things, "The Council recommends...a regulatory scheme such as the registration of radio stations, requiring no licensing process, to allow unlimited numbers of wireless systems such as base stations of wireless LAN systems operated outdoors at relatively high power to share frequencies under certain conditions..." The Council's full report in Japanese is online here: 電波政策ビジョン.
"Japan Issues E-Passports," by Jonathan Collins, RFID Journal, 28 March 2006: "The country expects to dispense more than 3.5 million e-passports within the next 12 months, with all Japanese passports will expected to carry an RFID chip within the next 10 years...."
"Japan to Push RFID Development" - an interview with Jun Murai, head of the Auto-ID Center's new lab in Japan, published in RFID Journal, 20 February 2003. Excerpt:
"RFID Journal: The UHF area of the spectrum can't be used for RFID tracking in Japan, but many other countries will use it. How will products with UHF tags be identified in Japan?
"Murai: We've been discussing this issue with the Japanese government, which has been very cooperative. Frequency reallocation will take five to 10 years, so we've been looking at other options. One is to use the frequencies around the 800 and 900 MHz. Another option is to use some areas of the spectrum that haven't been allocated. We haven't reached any conclusions yet on what is the best way to go..."
"Japan's UWB Finally Takes Off With Upcoming UWB-enabled Devices," by Hiroki Yomogita, Nikkei Electronics Online 3 August 2006: "The radio technique using ultra wideband UWB has been finally approved [for indoor use] in Japan. The news was announced in the official gazette of the Japanese government dated August 1, 2006... The allocated frequency bands are from 3.4 to 4.8 GHz and from 7.25 to 10.25 GHz. As for the 3.4-4.8 GHz band, it is required to use a technology to reduce interference with other radio services, although temporary measures are taken until the end of December 2008 to permit the use of the 4.2-4.8 GHz band without an interference reduction technology... Commenting on the future plans, an official of Japan's Ministry of Internal Affairs and Communications explains as follows. 'First, we will promote discussions to define the interference reduction technology. Then, we will discuss approval of sensor applications, for example, distance measurement. Although the latest announcement was limited to the approval of indoor usage, outdoor usage must also be discussed. In addition, we plan to set up a working group to discuss regulations on the 24 GHz band for use in automotive radars.' "
UWB 無線システム委員会報告 - Radio Systems Committee report on "technical requirements for UWB radio systems using the microwave band," March 2006, in Japanese: this will be the basis for MIC's initial set of UWB regulations.
"UWB to be Available in Japan in Early Summer 2006," by Tetsuo Nozawa, Nikkei Electronics, 2 February 2006: "Until December 31, 2008, devices with UWB system operating on the frequency between 4.2 and 4.8 GHz may be sold even without [a Detect And Avoid] function. An MIC source has told it is a 'temporary measure' for permitting the products to be sold before DAA function is completely developed. Further, the final report includes the following requirements... 1) Its application area is limited to indoors... 3) Use in aircrafts and vessels, and applications to toys and games are prohibited... 6) Technical requirements are to be revised when UWB system causes radio disturbance to the existing radio systems."
"R&D for Ubiquitous Platform Technology,"Wireless Watch Japan, 3 November 2010: "Machine Translation: 13 company three universities entrust 'Research and development of ubiquitous and the platform technology' of the Ministry of Public Management, Home Affairs, Posts and Telecommunications for the achievement of 'Ubiquitous network society' in which always, anywhere, and everyone can use the best telecommunication service according to the situation... Because information taken from the cell phone text message and the sensor is immediately reflected in the digital signage, the customer learns what where to be done now..."
ユビキタスネットワーキング研究所 (YRP Ubiquitous Networking Laboratory) - website in Japanese and English.