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- Development of Technical Examination Services Concerning Frequency Crowding
1.Purpose of the Technical Examination Services
The number of radio stations has increased rapidly in recent years, and in order to eliminate or minimize interference and airwave congestion arising from frequency crowding, it has become necessary to quickly implement technology that would allow the efficient use of radio waves.
For this purpose, technology that is believed to realize increased efficiency in radio wave use is placed under consideration from a technical perspective in order to expedite implementation under the technical examination services started in FY1996. This system is used to ease crowding of frequency experienced by those establishing and operating radio stations.
2.Outline of the Technical Examination Services
The process of establishing technical regulations, mainly centered on the technical examination service, is shown below.
Technology examination services cover the following three main areas.
1 Technology to improve transmission efficiency and frequency capacity
This covers technology to improve transmission efficiency and narrow down the frequency bandwidth per channel within existing frequency bands in order to increase the frequency that can be used for new allocations, thus improving the use of the existing frequency.
- Technology for narrowing, digitalization, etc.
- Intelligent control technology, etc.
2 Technology to lower or eliminate interference and jamming
This covers technology to lower or eliminate interference and jamming from other stations in frequencies where this prevented the allocation of frequency, thus improving frequency usage.
- Technology to lower or eliminate interference and jamming within the same medium
- Frequency sharing technology
- Electromagnetic environment and radio equipment measurement technology
3 Technology to increase use of high frequency bands
This covers technology to increase use of high frequency bands (3GHz and above), where technology is not established and usage is low.
- Microwave technology
- Millimeter-wave technology
3.Technical Examination Service Cases in FY2004
1.Improving transmission efficiency and frequency capacity
| Examinations conducted | |
|---|---|
| (1) Frequency sharing technology for low-power radio systems such as RFID Studies and evaluation tests of interference reduction technologies to realize coexistence between existing systems and low-power radio systems such as RFID, which is expected to be used in many situations of the Ubiquitous Networking Age. |
2004-2006 |
| (2) Effective frequency use technology of wide area radio system using a large-scale integrated array antenna Efficient frequency use technologies will be examined and studied for wide-area radio system by using an array antenna with a large number of antenna element, which is mounted at a high elevation point providing a high line-fo-sight probability to subscriber stations. |
2004-2006 |
| (3) S band personal mobile satellite communication technology Studies and demonstrations of the technical constraints and sharing criteria with other services for enhancing portable mobile earth stations, in order to introduce next-generation personal mobile satellite systems for facilitating effective frequency use through repetition and so on. |
2002-2005 |
| (4) Efficient frequency use technology on "Non-SOLAS AIS" Studies and evaluation tests to realize frequency sharing between "Non-SOLAS AIS" and "SOLAS AIS" (which has been installed on the ships defined in SOLAS convention* since July in 2002) in the VHF band of the maritime mobile service. "Non-SOLAS AIS" will be installed in small ships such as fishery boats that are not defined in the convention, and contribute to the maritime safety. *SOLAS Convention: International Convention for the Safety of Life at Sea,1974 |
2002-2004 |
| (5) Technology of advanced mobile communication system using VHF band etc Studies and evaluation tests to realize high speed transmission technology, eliminating interference technology and dynamic access control technology for advanced mobile communication system using VHF band etc. |
2002-2004 |
2.Lowering or eliminating interference and jamming
| Examinations conducted | |
|---|---|
| (1) Reduction technology of spurious emissions for Radars In order to reduce spurious emissions for radars and to enable efficient use of spectrum with other radio services operating in adjacent band, investigation and examination about the reduction technique of spurious emissions and the maintenance technique of the performance of installed radars are carried out. |
2004-2006 |
| (2) Examination regarding a measurement technology of the specific radio equipment to diversify Studies and evaluation testing regarding measurement technology with highly precise and simple radiated power in order to realize the specific radio equipment to diversify for decrease the variation by the shape of a terminal, or measurement environment and organization. |
2004-2006 |
| (3) Frequency sharing technology for UWB wireless system Studies and evaluation tests regarding frequency sharing conditions with other systems in order to realize PAN (Personal Area Network) using UWB wireless system for ultra-high speed data transmission in the short distance. |
2003-2005 |
| (4) Study regarding the effect of city noise on radio communications using microwave band Simulation, etc. to establish evaluation methods and countermeasures for deterioration of telecommunication quality regarding the effect of city noise on radio communications using microwave band (5GHz band, etc.). |
2003-2005 |
| (5) Interference suppression techniques for meteorological radars in heavy rainfall conditions For efficient utilization of frequency techniques to suppress mutual interference among meteorological radars in the 5GHz band are examined and verified by measuring the characteristics of bi-statically scattered radio waves by heavy rain in Okinawa. |
2003-2004 |
| (6) Frequency sharing technology for efficient use of microwave band Studies and evaluation tests regarding frequency sharing conditions with other systems in order to realize mobile wireless system and wireless access system for high speed internet using microwave band. |
2002-2004 |
| (7) Technology for efficient use of frequency for mobile service, for efficient use of cellular phone frequency Studies and evaluation tests to realize optimal placement for frequencies used for cellular phone systems using the 800MHz band, and studies to realize the optimal allocation of the additional band of IMT-2000. |
2001-2004 |
3. Increased use of high frequency bands
| Examinations conducted | |
|---|---|
| (1) Technology of advanced broadband radio relay link Studies and evaluation tests which contribute to effective use of frequencies for the broadband wireless network systems in the 30GHz and above band used for many different types of backbone networks. |
2004-2006 |
| (2) The compositional technology of the entrance circuit for cellular phones Studies and evaluation tests to contribute the introduction of the entrance circuit, which connect the base station of cellular phone with the control station. |
2003-2005 |
| (3) The technologies for Effective Use of Frequency using the Ka-band Fixed Satellite Communication Systems Studies for technical standards and co-frequency using standards with the other services, and executions on evaluation tests, etc. concerning VSAT earth stations using the compensation technology for rain attenuation and the other technologies, in order to introduce the Ka-band fixed satellite communication systems with broad bandwidth, adequate for realizing high speed data rate and high capacity, comparing to the popular Ku-band satellite communication systems at present. |
2002-2004 |
| (4) Satellite digital transmission technology for emergency and emergency prevention information Evaluation testing of frequency sharing conditions, etc. with existing systems in order to realize transmission of emergency information using digital images taken from a helicopter, via Ku band communication satellite. |
2001-2004 |
4.Evaluation System for Fair Technical Examination Services
Technical examination services rely on financing from spectrum use revenues, and in order to increase transparency and efficiency regarding operations, a research meeting to evaluate spectrum user fee technical examination services, comprised of external contributors, has been held since FY1997.
At this research meeting, each technology examination project is reviewed to determine whether sufficient results were obtained, and this evaluation is given back to the examiners to improve future technical examination services.
4.Evaluation System for Fair Technical Examination Services
Technical examination services rely on financing from spectrum use revenues, and in order to increase transparency and efficiency regarding operations, a research meeting to evaluate spectrum user fee technical examination services, comprised of external contributors, has been held since FY1997.
At this research meeting, each technology examination project is reviewed to determine whether sufficient results were obtained, and this evaluation is given back to the examiners to improve future technical examination services.
