1、QUESTION ITU-R 225/5*,*Interference to the aeronautical and maritime mobile servicesin the HF bands by unauthorized stations(2000)The ITU Radiocommunication Assembly,consideringa) that the aeronautical and maritime mobile services are used for safety communications;b) that WRC-2000 will consider a r
2、eview of the use of the HF bands by the aeronauticalmobile (R) and maritime mobile services with regard to the protection of safety relatedcommunications;c) that the need for protection of HF distress and safety communications on specificfrequencies is called for in Resolution 346 (WRC-97);d) that n
3、otwithstanding Resolution 207 (Mob-87) there is increasing interference fromnon-licensed use of HF transmitters, particularly to aircraft and ship communications;e) that this type of unauthorized operation is extremely difficult to monitor and control;f) that harmful interference is being frequently
4、 experienced on distress and safety channels;g) that aircraft and ships rely on HF for distress and safety communications, and will continueto do so for the foreseeable future;h) that elimination of this type of interference by the usual regulatory provisions underArticle 15 of the Radio Regulations
5、 has not been effective;j) that there may be technical solutions that can be implemented to mitigate interference,decides that the following Questions should be studied1 What are the possible techniques under development or in use which could providemitigation of interference to the reception of sig
6、nals in the HF band with particular reference toaeronautical and maritime HF operations?2 What are the technical characteristics, performance criteria and other factors of thesetechniques which would determine their effectiveness for use for interference mitigation inaeronautical (R) and maritime op
7、erations?further decides1 that the results of the above studies should be included in one or more Recommendations;2 that the above studies should be completed by 2005._* This Question should be brought to the attention of the International Civil Aviation Organization (ICAO)and the International Maritime Organization (IMO).* Former Question ITU-R 225/8.
