ProfessorattheDepartmentofElectronicEngineeringofTsinghuaUniversityanddirectorofNationalEngineeringLaboratoryforDigitalTV(Beijing).HehasledhisteamtodevelopDTMB,amandatorynationalstandardforChinesedigitaltelevision.
DTMB(DigitalTerrestrialMultimediaBroadcast)hassetamandatorynationalstandardforChinesedigitaltelevision.YangZhixingwasthefirsttotakechargeofdevelopingthisstandard.Attheendof2011,thankstotheeffortsofYangandhisteam,theDTMBsystemwasofficiallynominatedaninternationalstandard,alongsidethoseoftheUnitedStates,theEU,andJapan.TheInternationalTelecommunicationUnion(ITU)declaredDTMBtobe“amilestoneinthe40yearsofglobaldigitaltelevisiondevelopment,between1972and2012.”
SuccessfulDigitalConversion
Murreeisasmalltownlocated1.5hours’drivefromIslamabad,capitalofPakistan.Here,intheheartofthemountainsatanaltitudeof2,200meters,isacooperationprojectbetweenChineseandlocalcompanieswiththeaimofrealizingtheDTMBstandard.
OnApril20,2015,ChinesePresidentXiJinpingandPakistaniPrimeMinisterNawazSharifattendedinIslamabadtheinaugurationceremoniesofseveralbilateralcooperationprojects,includingthatforDTMB,thefirstintheChina-PakistanEconomicCorridor.
Pakistan,oneofthecountriesalongtheBeltandRoadroutes,ischaracterizedbyhugemountains,immensedesertsandvariedclimate.Afewyearsago,Pakistan’snationaltelevisionincreaseditsresearchintodigitaltelevisionstandards.Atthattime,theITUhadrecognizedonlyfourstandardsworldwide:ATSCoftheU.S.,DVB-T/T2ofEurope,ISDBofJapan,andDTMB/DTMB-AofChina.Duringthetestphase,PakistanwasextremelyimpressedbytheChinesestandard,whosepotentialexceededallexpectations,andthereforepreferredDTMBaboveallthefouravailablestandards.
Thisstandardwasnotdevelopedovernight.YangZhixingwitnesseditsbirthandgrowth.Inthe1990s,foreignresearchersbeganworkingtoconverttheanalogsignaltodigital.In1994,academicslikeWuYoushouandYePeida,mentorsofYangZhixing,urgedthenationtoseizetheopportunityofferedbythedigitalrevolutioninthetelevisionsector.ThiscallcaughttheattentionofChina’spolicymakers.
“ChinahaslongheldtheworldrecordfortheproductionofcolorTVsanddomestictelevisionownership.However,inthedaysoffirstblack-and-white,andthencolortelevisionthatprecededthetransitiontodigitaltechnology,ChinaadoptedtheEuropeanstandardwithouthavingintellectualpropertyrightsoverkeytechnologies,”explainedYangZhixing.Atthattime,hewasresearchingthedevelopmentofsatellitereceiverdemodulators,butheforesawthepotentialofdigitaltelevision.Heunderstoodthatthistechnologywouldsoonrepresentamajorshift,allowingeveryonetowatchthesmallscreenathighquality.
In1999,theNationalDigitalTelevisionLeadingGroupwasestablishedinChinawiththeaimofdevelopingadomesticstandardfordigitaltelevision.Inthesameyear,aresearchcenterspecializingindigitaltele-transmissiontechniqueswasestablishedatTsinghuaUniversity.YangZhixingwasinchargeofthisproject.
“Digitalhastrulyrevolutionizedthesmallscreen.ThequalityismuchbettertodaythanwithanalogTV,”Yangsaid.
SuperiorityofChineseStandard
WhatarethestrengthsoftheChinesestandardincomparisonwiththeotherthreestandards?Inshort,itisbasedonastablesystem,hasahighspectralefficiency,usesbroadbandandcoversawiderarea.
Inaddition,theChinesestandardadoptslowdensityparitycheck(LDPC),anewerror-correctionlinearcode.InventedbyRobertGallager,anAmericanprofessorattheMassachusettsInstituteofTechnology(MIT)inthe1960s,theLDPCsystemensuredoptimumerrorcorrection,butduetoitstechnicalcomplexityitwasnotuntilthe1990sthatitwasfinallyimplemented.ThegroupheadedbyYangZhixingwasthefirsttointegratethisLDPCsystemintoadigitaltelevisionstandard.Nowadays,second-generationstandardsinEuropeandtheUnitedStatesalsousethisLDPCsystem.
InAugust2006,theChinesestandardwasunveiledandbecamemandatorynationally.Duringthe2008BeijingOlympicGames,thisnewstandardwastestedintheeighthostcitiesofthiscompetition,includingBeijing,ShanghaiandZhuhai.IthassincebeenextendedtootherChinesecitiesandprovinces,andwithmoreinvestmentcouldexpandtonationwidecoverage.
In2006,HongKongannounceditsintentiontoadopttheEuropeanstandard.Nevertheless,thefollowingyear,YangZhixingandhisgroupvisitedHongKong,andtheirstandardwastrialedforsixmonths.AstheChinesestandardclearlysurpassedthatinforceinEurope.HongKongthenchangeditsmindandoptedfortheformer.Todate,70percentofHongKongviewersbenefit.
EncouragedbythissuccessintheHongKongmarket,between2008and2009,YangZhixingrepeatedlyvisitedfourLatinAmericancountries,namelyCuba,Venezuela,Peru,andEcuador.Hemadesomanytripsthathelostcount.“Overtwoyears,IhaveaccumulatedenoughairmilesonmyAirChinaandAirFranceloyaltycardstoqualifyforagoldcard,eventhoughIfleweconomyclass,”jokedYangZhixing.
YangZhixingknowstheforeigntechnologiesinsideout.HeiscertainoftheexcellenceoftheChinesedigitaltelevisionstandard.“Itdidnotfailasingletest!”heexclaimed,adding:“Ofalltheinternationalstandards,ourshasbeenrecognizedassuperiorbyallthecountriesthathavetestedit.”
InVenezuela,thelocaltestinvolvedfivecriteria,andtheChinesestandardrankedfirstinfour.Thankstoitsconstanthighperformance,itisgraduallygainingasolidreputationinternationally.
DiffusionofAdvancedTechnologies
Competitionbetweenterrestrialdigitaltelevisionstandards,whichhavestrongpoliticalconnotations,isnotcomparabletothatbetweentwobrandsofordinaryproducts.Beyondthechoiceofthenorm,itmustberegardedasasymbolofnationalsovereignty.
AnationalworkinggroupwasestablishedinSeptember2009,consistingofmembersfromeightministries,includingtheNationalDevelopmentandReformCommissionandtheMinistryofForeignAffairs,withtheaimofdisseminatingtheChinesedigitalTVstandardglobally.Atthesametime,theNationalDigitalTelevisionLeadingGroupdecidedtosubmittheChinesestandardtotheITUforitsapproval.
In2011,theITUpaidcloseattentiontotheChinesestandard.ItestablishedatechnicalgroupspecificallytomonitorthedevelopmentoftheDTMBsystem.Representativesfrom78countriesparticipatedinthisgroup.Finally,theChinesestandardwascommendedforitshighperformanceandwasrecognizedasaninternationalstandard.
YangZhixingiscognizantoftheimpactofthespreadofastandardonthewholeindustrialchain.“Intheneweconomicera,standardsareawayofexploringnewmarkets.Ininternationalcompetition,standardsareapowerfulmeansofovercomingadversaries,”hesaid.
Amongthefoursystemsofthefirstgeneration,theChinesestandardenjoysasignificantadvantage.Thisiswhy14countriesandregionshavenowembracedtheDTMBsysteminAsia,AfricaandLatinAmerica,coveringnearlytwobillionpeople.
InadditiontoobtainingthispreciousstatusfromtheITU,thesuperiorityofthisstandardhasearnedYangZhixingandhisgroupotherhonors,includingthehighestprizeoftheNationalScienceandTechnologyProgressAwardin2016.
AccordingtoPanChangyong,aresearcherwhohasbeenworkingforyearsontheestablishmentofChinesetechnologicalstandards,“Wemustdistinguishtwotypesofproductsin‘goingglobal’:goodsfromthemoretraditionalmanufacturingindustry,suchaslaptops,televisions,shoes,andclothing;andstandards,whicharepartoftheexportofadvancedtechnologies.”
Inrecentyears,Europehaslauncheditssecondgenerationinternationaldigitaltelevisionstandard,whileYangZhixingandhisgrouphaveupgradedtheDTMBstandardtoDTMB-A.Henowexpectsthatin2017,withthedevelopmentoftheBeltandRoadInitiative,theindustrialchainoftheDTMB-AsystemwillexpandrapidlyandthattheChinesestandardwillgaingroundabroad.
YangZhixing(secondfromleft)inagroupphotowithCubanNationalTVStationworkersin2008,havinggonetoCubatododigitalTVnormativetesting.majorshift
Heunderstoodthatthistechnologywouldsoonrepresentamajorshift,allowingeveryonetowatchthesmallscreenathighquality.