REPORT FROM BRAZILIAN ASSOCIATION OFBROADCASTING ABOUT THE TEST RESULTS IN AM ANDFM STATIONS THAT USE THE IBOC STANDARD

摘要

Since 1996, the Brazilian Broadcasting has turned tornthe introduction of digital technology in their AM andrnFM stations. The main objective was to keep thernstations installed plant putting on the air both analogrnand digital transmissions. Only two digital systemsrnwere possible to test so as to attend this principle:rnIBOC and DRM. The others were considered a newrnservice. The European Eureka 147 and the JapanesernISDB-Ts can be shown as examples of such newrnservice. For Brazilians Broadcasters it was notrnpossible to give up their AM and FM stations and tornmove towards establishing new stations with theirrnrespective new services and for the listeners as well itrnwould not be worth giving up their AM and FMrnreceivers having to purchase exclusively digitalrnreceivers. Twenty stations in Brazil went to digitalrntransmission, ten AM stations and ten FM stationsrninstalled digital system in their plants.rnAfter the National Telecommunication Agency –rnAnatel, a regulatory agency, published in theirrnwebsite the IBOC AM and IBOC FM guides, twornprocedures were developed1: "The Tests of FieldsrnProcedures to Hybrid Digital AM IBOC System" andrn"The Tests of Fields Procedures to Hybrid DigitalrnIBOC FM System". Thus, it was possible to organizernthe experience with the IBOC technology at thernstations.rnThe Brazilian Association of Broadcasting - ABERT2rninvited the Universidade Presbiteriana Mackenzie,rnsome consultants and engineering from stations torncarry out the tests with supervision of Anatel andrnMinistry of Communications technicians.rn1 www.anatel.gov.br/radiodifus?o/rádiodigitalrn2rnhttp://www.abert.org.brovosite/assessorias/tecnica/a_tec_rnrd.cfmrnTwo principles were established for evaluation ofrnAM and FM Hybrid Digital Systems (IBOC – HDrnRadio):rnAssessment of performance of digital servicerncomprising:rn1. Robustness of digital signal;rn2. Coverage area; andrn3. Digital audio quality.rnAssessment of compatibility of hybrid digital signalrnIBOC AM and IBOC FM:rn4. with the existent analog signal in the PBFM andrnPBOM 4;rn5. with the host analog signal, andrn6. with the other involved digital signals.