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  5. Frequency Coordination


1.Purpose of Frequency Coordination

Frequency coordination is, preceding its use, the technical coordination of frequencies (including geostationary orbits) conducted by the authorities who are planning the radiocommunication network, on the basis of the Radio Regulation(RR) enacted by the International Telecommunication Union (ITU), in order to prevent the frequencies radiocommunication networks from causing harmful interference to the networks of foreign counties.

2.Flow of Frequency Coordination

(1) General overview of frequency coordination

a) Systems for notice and registration of frequency

Notification to ITU and recording in the Master International Frequency Register (MIFR) of the frequency assignments are required when the frequency to be used falls under: 1. The frequency could give harmful interference to the radiocommunications services of other authorities; 2. The frequency is used for international radiocommunications; 3. it is necessary to conduct coordinating procedures; 4. To obtain international recognition (RR 11).

Frequency assignments of notification will be registered if applicable after examinations by ITU of: 1. Conformity to the concerned provisions such as frequency assignment; 2. Completion of the required frequency coordination; 3. Whether or not harmful interference is given to other registered frequency assignments

Figure 1:Flow of notification and recording system of frequency

b) Coordination of frequency

Technical coordination on satellite communications and terrestrial broadcasting systems (using the HF and MF band) which are subject to cause interference troubles in different countries among each country, preceding notification, will be made among the concerned countries.

Figure 2:Flow of international coordination on frequency

(2) Overview of frequency coordination of satellite communications networks

a) Flow of coordination of satellite networks

Flow of coordination of satellite networks is divided into four steps, as shown below:

General flow of frequency coordination of satellite networks
General flow of frequency coordination of satellite communication networks

1. Forwarding and publication of advance publication materials to ITU

From two to five years prior to the use of sattelites communications networks, the authority forwards the materials to ITU which makes them public to all authorities.

2. Coordination

Coordination with all administrations that may be affected.

Coordination of satellite networks (1)
Figure 3:Coordination of satellite communication networks (1)
Coordination of satellite networks (2)
Figure 4:Coordination of satellite communication networks (2)

3. Notification

Notification of frequency assignment is to be given to ITU not later than three years prior to the use of satellite networks

4. Registration

Frequency assignments of notification which satisfy the related regulations of RR and completed required coordination shall be recorded in the MIFR, and will be internationally recognized with regard to frequency assignment use.

b) Types of frequency coordinations of satellite communications networks

Various types of frequency coordination of satellite networks are indicated by RR, according to the type of satellite networks (GEO, non-GEO), or the frequency and service. One is establishing an associated plan for all nations, in which global assignments previously planned for all countries in order to ensure a certain number of the channels, and is applied mainly to broadcast satellites. Another one is the First-come-first-served basis; the priority for the use of frequency comes to be accepted in the order of arrival, and comes to be applied mainly to radiocommunications satellites. The coordination of each method is shown below.

1. Establishing an associated plan for all nations

2. First-come-first-served basis

Coordination between Earth station and terrestrial station
Figure 5:Coordination between Earth station and land station

c) Others

1.Validity of registration of frequency assignment

A frequency assignment recorded in MIFR is valid for the period of validity after the date of usage shown below. The period of validity is generally determined by the design-life of satellites and renewal of valid term may be allowed from three years before the expiration, if it is of the same characteristics. (Rev.WRC-03 Resolution 4)

2.Date of bringing into use

The date of bring into use satellite communications networks is stipulated as it begins from the date of receiving advance publication of materials by ITU for the period within a maximum of five years. In particular cases, such as failure of the launching of a rocket or modification of satellite design, a two year extension may be allowed.

In the case the notification of frequency assignment is given before use, notification for verifying related frequency assignment shall be given to ITU within 30 days after use. (RR 11.47)

3.administrative due diligence information

The due diligence information relating to the identity of the satellite network and the spacecraft manufacturer shall be submitted to ITU within seven years after the date of receipt by ITU of the information for the advanced publication. (Rev.WRC-03 Resolution 49)

Copyright(C)Telecommunications Bureau of the Ministry of Internal Affairs and Communications All Rights Reserved.
Copyright(C)Telecommunications Bureau of the Ministry of Internal Affairs and Communications All Rights Reserved.