2. On the interpretation of this footnote
When considering provision 5.340 one has to take two things into account:
Emissions in the band of concern
Emissions from outside the band of concern, regardless of its origin.
Both cases are covered in the Rules of Procedure of the ITU but perhaps not yet to a
satisfactory level.
According to the ITU Radio Regulations (article 1.138), Emission is defined as radiation
produced, or the production of radiation, by a radio transmitting station. For example, the energy
radiated by the local oscillator would not be an emission but a radiation.
This leads to the conclusion that emission, as defined by the Radio Regulations, always relates
to some kind of transmitting radio station. The Radio Regulations do not provide a definition
for transmission nor an explanation of the difference between emission and transmission.
Nevertheless, the first conclusion is, that it is not allowed to assign station in a frequency
band to which footnote 5.340 applies.
In line with this is the view of the Radio Regulations Board. Its interpretation can be summarized
as follows (cf.: the Rules of Procedure of the ITU on this issue):
"2. Emissions in bands where uses other than those authorized are prohibited
2.1. The provisions listed below relating either to frequencies or bands to be used for safety
and distress communications or allocated for passive usage prohibit any other use:
a) Provisions relating to safety and distress communications:
aa) Appendix 13 (Part A2) (Non-GMDSS): § 13, 15(1), 16(1), 17A, 18(1);
ab) Appendix 15 (GMDSS), Tables 15-1 and 15-2 (frequencies marked with an asterisk (*) to indicate that any emission causing harmful interference to distress and safety communications is prohibited).
b) Provisions relating to passive usage: Nos. 5.267 and 5.340.
2.2 The Board considers that, in view of this prohibition, a notification concerning any
other use than those authorized in the band or on the frequencies concerned cannot be
accepted even with a reference to No. 4.4; furthermore the administration submitting such a
notice is urged to abstain from such usage.
In the case of assigning frequencies in a band to which 5.340 applies to radio stations
the notes Nos. 2.1b and 2.2 shall apply."
Considering the assignment of frequencies to stations adjacent to the frequency band of concern
the decision below shall apply.
"To resolve cases of harmful interference between services in adjacent bands it was decided
that, irrespective of the phenomena at the origin of the interference (out-of-band emission,
intermodulation products, etc.), the administration responsible for the emission overlapping
a non-allocated band shall use appropriate means to eliminate the interference."
In conclusion one can state that the footnote 5.340 is meant to guarantee that the
production of radiation by radio transmitters in a passive band is prohibited by all
means. To resolve cases of harmful interference between services in adjacent bands and
allocated services in such a band, irrespective of the phenomena at the origin of the
interference (out-of-band emission, intermodulation products, etc.), emission overlapping
the non-allocated band shall be attenuated appropriate to eliminate interference which is
detrimental for the service(s) protected by this footnote.
Last modified: November 15, 2004
Committee on Radio Astronomy Frequencies