1、International Civil Aviation Organization Regional Preparatory Group (RPG) Meeting for World Radiocommunication Conference 2007 (WRC-2007), ACP Working Group B and F and NSP SSG Meetings. Bangkok, Thailand, 21-25 February 2005. RPG/ACP/NSP pres4,Agenda Item 5SPECIFICS ON FM BROADCAST INTERFERENCE AN
2、D LATEST WORKpresentation by Steve Mitchell,A LITTLE BIT OF HISTORY,Changes to ITU Radio Regulations recognition of potential interference to aeronautical systems studies within the ITU initial studies further enhanced studies final ITU recommendations,GENERAL TYPES OF INTERFERENCE,Four types of int
3、erference to consider Type A A1 A2 Type B B1 2 signal 3signal B2,DIFFICULTIES WITH ILS/VOR/COM,Extensive testing ILS/VOR receivers 3rd order intermodulation saturation Com receiversICAO Annex 10 SARPs requirements 3rd order 2 signal Desensitisation,DIFFICULTIES WITH GBAS AND VDL 4,Testing of GBAS an
4、d VDL 4 receivers same mechanisms apply as for ILS/VOR/COM avionics manufacturers tests above 112 MHz split in desensitisation requirements similar A1and B1 criteria as ILS/VORICAO Annex 10 SARPs requirements 3rd order 2 signal Desensitisation,Co-ordination,Why co-ordination? Between FM broadcasters
5、 mutual sharing Between FM broadcasters and aeronautical avoid interference to aeronautical services Between aeronautical and FM broadcasters avoid potential problems,Example of co-ordination process,Example of an approach to co-ordination European example inside a State databases computer tools agr
6、eement mechanism between States LEGBAC/EBU,TYPE A1 CALCULATION,TYPE A2 CALCULATION,TYPE B1 CALCULATION 2 SIGNAL,TYPE B1 CALCULATION 3 SIGNAL,TYPE B2 CALCULATION,TRIGGER AND CUT-OFF CALCULATIONS,ILS PROTECTION,VOR PROTECTION,CURRENT STATUS OF WORK,ITU Working Party 8B Development of new recommendation Information on interference to FM receiversICAO NSP SSG ICAO input to ITU,FURTHER WORK WITHIN ICAO,ILS GBAS No compatibility shown VDL 4 No compatibility shown,
