TS 101 191 - V1.3.1 - Digital Video Broadcasting (DVB); DVB mega-frame for Single Frequency Network (SFN) synchronization

18 Pages·0.12 MB·English

by  European Telecommunications Standards Institute

ETSI TS 101 191
V1.3.1
(2001-01)
TechnicalSpecification
Digital Video Broadcasting (DVB);
DVB mega-frame for Single Frequency Network (SFN)
synchronization
EuropeanBroadcastingUnion UnionEuropéennedeRadio-Télévision
EBU·UER
2 ETSITS101191V1.3.1(2001-01)
Reference
RTS/JTC-DVB-93
Keywords
Broadcasting,digital,video,DVB,TV
ETSI
650RoutedesLucioles
F-06921SophiaAntipolisCedex-FRANCE
Tel.:[phone] Fax:[phone]
SiretN°34862356200017-NAF742C
Associationàbutnonlucratifenregistréeàla
Sous-PréfecturedeGrasse(06)N°7803/88
Importantnotice
Individualcopiesofthepresentdocumentcanbedownloadedfrom:
http://www.etsi.org
Thepresentdocumentmaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingor
perceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).
Incaseofdispute,thereferenceshallbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrive
withinETSISecretariat.
Usersofthepresentdocumentshouldbeawarethatthedocumentmaybesubjecttorevisionorchangeofstatus.
InformationonthecurrentstatusofthisandotherETSIdocumentsisavailableathttp://www.etsi.org/tb/status/
Ifyoufinderrorsinthepresentdocument,sendyourcommentto:
[email protected]
CopyrightNotification
Nopartmaybereproducedexceptasauthorizedbywrittenpermission.
Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.
©EuropeanTelecommunicationsStandardsInstitute2001.
©EuropeanBroadcastingUnion2001.
Allrightsreserved.
ETSI
3 ETSITS101191V1.3.1(2001-01)
Contents
IntellectualPropertyRights..........................................................................................................................4
Foreword......................................................................................................................................................4
1 Scope..................................................................................................................................................5
2 References..........................................................................................................................................5
3 Definitionandabbreviations...............................................................................................................5
3.1 Definitions..................................................................................................................................................5
3.2 Abbreviations..............................................................................................................................................5
4 Generaldescription.............................................................................................................................6
4.1 SFNsystemblocks......................................................................................................................................7
5 Mega-framedefinition........................................................................................................................8
6 Mega-frameInitializationPacket(MIP)..............................................................................................9
6.1 Functions..................................................................................................................................................12
6.1.1 Transmittertimeoffsetfunction...........................................................................................................12
6.1.2 Transmitterfrequencyoffsetfunction...................................................................................................13
6.1.3 Transmitterpowerfunction..................................................................................................................13
6.1.4 Privatedatafunction............................................................................................................................13
6.1.5 Cellidfunction....................................................................................................................................14
6.1.6 Enablefunction....................................................................................................................................14
AnnexA(normative): CRCdecoder model...................................................................................15
AnnexB(normative): FunctionaldescriptionofSFNsynchronization........................................16
AnnexC(normative): ReconfigurationofDVB-T modulatorparametersbyusingtheMIP......17
History.......................................................................................................................................................18
ETSI
4 ETSITS101191V1.3.1(2001-01)
Intellectual Property Rights
IPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.Theinformation
pertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefound
inETSISR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIin
respectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWeb
server(http://www.etsi.org/ipr).
PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.Noguarantee
canbegivenastotheexistenceofotherIPRsnotreferencedinETSISR000314(ortheupdatesontheETSIWeb
server)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.
Foreword
ThisTechnicalSpecification(TS)hasbeenproducedbyJointTechnicalCommittee(JTC)BroadcastoftheEuropean
BroadcastingUnion(EBU),ComitéEuropéendeNormalizationELECtrotechnique(CENELEC)andtheEuropean
TelecommunicationsStandardsInstitute(ETSI)(Broadcast).
NOTE: TheEBU/ETSIJTCBroadcastwasestablishedin1990toco-ordinatethedraftingofstandardsinthe
specificfieldofbroadcastingandrelatedfields.Since1995theJTCBroadcastbecameatripartitebody
byincludingintheMemorandumofUnderstandingalsoCENELEC,whichisresponsibleforthe
standardizationofradioandtelevisionreceivers.TheEBUisaprofessionalassociationofbroadcasting
organizationswhoseworkincludestheco-ordinationofitsmembers'activitiesinthetechnical,legal,
programme-makingandprogramme-exchangedomains.TheEBUhasactivemembersinabout60
countriesintheEuropeanbroadcastingarea;itsheadquartersisinGeneva.
EuropeanBroadcastingUnion
CH-1218GRANDSACONNEX(Geneva)
Switzerland
Tel: [phone]
Fax: [phone]
DigitalVideoBroadcasting(DVB)Project
FoundedinSeptember1993,theDVBProjectisamarket-ledconsortiumofpublicandprivatesectororganizationsin
thetelevisionindustry.ItsaimistoestablishtheframeworkfortheintroductionofMPEG-2baseddigitaltelevision
services.Nowcomprisingover200organizationsfrommorethan25countriesaroundtheworld,DVBfosters
market-ledsystems,whichmeettherealneeds,andeconomiccircumstances,oftheconsumerelectronicsandthe
broadcastindustry.
ETSI
5 ETSITS101191V1.3.1(2001-01)
1 Scope
Thepresentdocumentspecifiesamega-frame,includingamega-frameinitializationpacket(MIP),whichmaybeused
forsynchronizationoftheSingleFrequencyNetworks(SFN)aswellasfortheoptionalcontrolofotherimportant
parametersinanSFN.
2 References
Thefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresent
document.
• Referencesareeitherspecific(identifiedbydateofpublicationand/oreditionnumberorversionnumber)or
non-specific.
• Foraspecificreference,subsequentrevisionsdonotapply.
• Foranon-specificreference,thelatestversionapplies.
[1] ISO/IEC13818-1(1994):"InformationTechnology-Genericcodingofmovingpicturesand
associatedaudioinformation:Systems".
[2] ETSIEN300744:"DigitalVideoBroadcasting(DVB);Framingstructure,channelcodingand
modulationfordigitalterrestrialtelevision".
[3] ETSIEN300468:"DigitalVideoBroadcasting(DVB);SpecificationforServiceInformation(SI)
inDVBsystems".
3 Definition and abbreviations
3.1 Definitions
Forthepurposesofthepresentdocument,thefollowingtermsanddefinitionsapply:
cell:forthedefinitionofacell,seeEN300468[3],clause3.1
frame:forthedefinitionofaDVB-Tframe,seeEN300744[2],clause4.4
super-frame:forthedefinitionofaDVB-Tsuper-frame,seeEN300744[2],clause4.4
3.2 Abbreviations
Forthepurposesofthepresentdocument,thefollowingabbreviationsapply:
CRC CyclicRedundancyCheck
DVB DigitalVideoBroadcasting
DVB-T DVB-Terrestrial
ERP EffectiveRadiatedPower
GPS GlobalPositioningSystem
HP HighPriority
LP LowPriority
MFN MultiFrequencyNetwork
MFP Mega-FramePacket
MIP Mega-frameInitializationPacket
MPEG MovingPicturesExpertGroup
PID PacketIDentifier
pps pulsepersecond
ETSI
6 ETSITS101191V1.3.1(2001-01)
RF RadioFrequency
RS Reed-Solomon
SFN SingleFrequencyNetwork
SI ServiceInformation
STS SynchronizationTimeStamp
SYNC SYNChronization
TPH TransportPacketHeader
TPS TransportParameterSignalling
TS TransportStream
TX/RX Transmitter/Receiver
4 General description
Figure1showsablockdiagramofacompleteSFNsystem.
MPEG-2
TS
RX
SYNC DVB-T
MPEG-2 Network
system modulator
TS adapter
10MHz 1pps
MPEG-2 SFN TX Distribution
remultiplexer adapter Network GPS(note)
Network
adapter
10MHz 1pps
RX
SYNC DVB-T
Network
GPS(note) system modulator
adapter
MPEG-2 10MHz 1pps
TS
GPS(note)
NOTE: Couldbeanycommonavailablefrequencyreference.
Figure1:DVB-TprimarydistributionwithSFNadaptation
TheSFNfunctionalityisanextensiontotheDVBsystem.TheblocksassociatedwithSFNfunctionalityarethegrey
boxesinfigure1.Theseblockscouldbeimplementedeitherasseparateequipmentorintegratedinthemultiplexer
and/ortheDVB-Tmodulator.
ETSI
7 ETSITS101191V1.3.1(2001-01)
4.1 SFN system blocks
MPEG-2re-multiplexer
TheMPEG-2re-multiplexerre-multiplexestheprogrammesfromvariousinputchannels,updatestheSIandprovides
anMPEG-2TSwhich,afterSFNadaptation,istransmittedviatheDVB-TmodulatorsintheSFN.
SFNadapter
TheSFNadapterformsamega-frame,consistingofnTS-packetscorrespondingto8DVB-Tframesinthe8Kmodeor
32framesinthe2Kmode,andinsertsaMega-frameInitializationPacket(MIP)withadedicatedPIDvalue.Inserted
anywherewithinamega-frameofindexM,theMIPofthatmega-frame,MIP ,allowstouniquelyidentifythestarting
M
point(i.e.thefirstpacket)ofthemega-frameM+1.ThisisaccomplishedbyusingapointercarriedbytheMIP itself
M
toindicateitspositionwithregardstothestartofthemega-frameM+1.
Thetimedifferencebetweenthelatestpulseofthe"one-pulse-per-second"reference,derivede.g.fromGPS,that
precedesthestartofthemega-frameM+1andtheactualstart(i.e.firstbitoffirstpacket)ofthismega-frameM+1is
copiedintotheMIP .ThisparameteriscalledSynchronizationTimeStamp(STS).
M
Thetimedurationofamega-frameisindependentofthedurationT constellationandcoderateoftheDVB-Tsignal.
,
u
Fourdifferenttimedurationsexist,foreachtypeofchannelwidth,dependingonthechosenguardintervalproportion,
asshowntable1a:
Table1a
GuardInterval Channelwidth
(∆∆∆∆/T) 6MHz 7MHz 8MHz
u
1/4 0,812373 0,696320 0,609280
1/8 0,731136 0,626688 0,548352
1/16 0,690517 0,591872 0,517888
1/32 0,670208 0,574464 0,502656
TheoutputoftheSFNadaptershallbefullyDVB/MPEG-2TScompliant.
Transmitter/Receivernetworkadapter
ThenetworkadaptersshallprovideatransparentlinkfortheMPEG-2TSfromthecentraltothelocalunits.The
maximumnetworkdelay-causedbythedifferentpathsofthetransmissionnetwork-theSYNCsystemcanhandleis
1second.
SYNCsystem
TheSYNCsystemwillprovideapropagationtimecompensationbycomparingtheinsertedSTSwiththelocaltime
referenceandcalculatetheextradelayneededforSFNsynchronization.SeeannexBforanexampleofthe
synchronizationprocess.
DVB-Tmodulator
Themodulatorshouldprovideafixeddelayfromtheinputtotheairinterface.TheinformationinsertedintheMIP
couldbeusedforthedirectcontrolofthemodulatormodesorcontrolofothertransmitterparameters.Themodulator
clocksatthedifferentsiteshavetobesynchronized.SinceitisarequirementofanSFNthatalltransmittedsignalsbe
identical,theMPEG-2TSinputstothevariousDVB-Tmodulatorshavetobebitidentical.
GlobalPositioningSystem(GPS)
GPSisoneamongmanypossibletimereferencesbutitistheonlyoneavailableglobally.GPSreceiversareavailable
whichprovidebotha10MHzfrequencyreferenceanda1pulsepersecond(1pps)timereference.The1ppstime
reference,usedinSFNsynchronization,isdividedinto100nsstepsofthe10MHzclock.The10MHzsystemclockis
assumedtobeavailableatallnodesinthenetwork.
Thefunctionalblocks"SFNadapter"and"SYNCsystem"areadditionalelementsforSFNuse,andnotnecessaryin
MFNapplications.
ETSI
8 ETSITS101191V1.3.1(2001-01)
5 Mega-frame definition
TheoutputoftheSFNadaptershallbeavalidMPEG-2TS,wheretheindividualpacketsareorganizedingroups,
whichconstituteamega-frame.Eachmega-frameconsistsofnpackets,wherenisanintegernumberwhichdependson
thenumberofRS-packetspersuper-frameintheDVB-TmodethatwillbeusedforDVB-Temissionofthe
MPEG-2TS(seeEN300744[2],clause4.7).Inthe8Kmodenis(thenumberofRS-packetspersuper-frame)×2.In
the2Kmodenis(thenumberofRS-packetspersuper-frame)×8.
Eachmega-framecontainsexactlyoneMega-frameInitializationPacket(MIP).Theactualpositionmayvaryinan
arbitrarywayfrommega-frametomega-frame.ThepointervalueintheMIPisusedtoindicatethestartofthe
followingmega-frame.Infigure2theoverallstructureofthemega-frame,includingthepositioningoftheMIP,is
given.TheexactdefinitionoftheMIPformatisgiveninclause6.
Mega-frame
FirstPacket MIP LastPacket
MFP#0 MFP#1 ….. MFP#p ….. MFP#n-1 MFP#0
Pointer=(n-1)-p
Thepointerindicatesthelocation
ofthefirstpacketofthenext
mega-frame.
Figure2:Overallmega-framestructure
Thestartofamega-frameintheDVB-Tsignalisinthepresentdocumentdefinedtocoincidewiththebeginningofa
DVB-Tsuper-frameandthestartofaninvertedsyncbyte,beingpartoftransportmultiplexadaptation.
Theuseofamega-frameandtheinsertionofaMIPareadditionalelementsforSFNuse,andnotnecessaryinMFN
applications.
ETSI
9 ETSITS101191V1.3.1(2001-01)
6 Mega-frame Initialization Packet (MIP)
TheMIPisanMPEG-2compliantTransportStream(TS)packet,madeupofa4-byteheaderanda184-bytedatafield.
TheorganizationoftheMIPisshownintable1b.
Table1b:Mega-frameInitializationPacket(MIP)
Syntax Numberofbits Identifier
mega-frame_initialization_packet(){
transport_packet_header 32 bslbf
synchronization_id 8 uimsbf
section_length 8 uimsbf
pointer 16 uimsbf
periodic_flag 1 bslbf
future_use 15 bslbf
synchronization_time_stamp 24 uimsbf
maximum_delay 24 uimsbf
tps_mip 32 bsblf
individual_addressing_length 8 uimsbf
for(i=0;i<N;i++){
tx_identifier 16 uimsbf
function_loop_length 8 uimsbf
for(i=0;i<N;i++){
function()
}
}
crc_32 32 rpchof
for(i=0,i<N,i++){
stuffing_byte 8 uimsbf
}
}
NOTE1: Optionalparametersareshowninitalic.
NOTE2: AllparametervaluesintheMIP applytomega-frameM+1,i.e.tothemega-framepointedoutbythepointer,
M
exceptforthetps_mipwhichdescribestheparametersofmega-frameM+2.SeeannexCfordetails.
NOTE3: ForthedefinitionoftheCRCdecodermodel,seeannexA.
NOTE4: ThelengthofaMIPshall alwaysbe188bytes.
transport_packet_header:Thetransport_packet_headershallcomplywithISO/IEC13818-1[1]clause2.4.3.2,
tables2and3.
ThePIDvaluefortheMega-frameinitializationPacket(MIP)shallbe0x15.
Thepayload_unit_start_indicatorisnotusedbytheSFNsynchronizationfunctionandshallbesetto1.
Thetransport_priorityvalueisnotusedbytheSFNsynchronizationfunctionandshallbesetto1.
Thetransport_scrambling_controlvalueshallbesetto00(notscrambled).
Theadaptation_field_controlvalueshallbesetto01(payloadonly).
AllotherparametersareaccordingtoISO/IEC13818-1[1]clause2.4.3.2.
TheTransportPacketHeader(TPH)ismandatory.
MandatorySFNparameters
synchronization_id:thesynchronization_idisusedtoidentifythesynchronizationschemeused(seetable2).
Table2:Signallingformatforthesynchronization_id
Synchronization_id Function
0x00 SFNsynchronization
0x01-0xFF Futureuse
ETSI
10 ETSITS101191V1.3.1(2001-01)
section_length:thesection_lengthspecifiesthenumberofbytesfollowingimmediatelyafterthesection_lengthfield
until,andincluding,thelastbyteofthecrc_32butnotincludinganystuffing_byte.Thesection_lengthshallnotexceed
182bytes.
pointer:thepointerisa2-bytebinaryintegerindicatingthenumberoftransportpacketsbetweentheMIPandthefirst
packetofthesucceedingmega-frame.
TherangeofthepointerdependsontheDVB-Tmodeusedforemission.
periodic_flag:indicatesifaperiodicoranaperiodicinsertionoftheMIPisperformed.Periodicinsertionmeansthat
thevalueofthepointerisnottimevarying.A"0"indicatesaperiodicmodeanda"1"indicatesperiodicmode.AllSFN
"SYNCsystems"shallbeabletohandlebothaperiodicandperiodicmode.
future_use:reservedforfutureuse.
synchronization_time_stamp:thesynchronization_time_stampofMIP containsthetimedifference,expressedasa
M
numberof100nssteps,betweenthelatestpulseofthe"one-pulse-per-second"reference(derivede.g.fromGPS)that
precedesthestartofthemega-frameM+1andtheactualstart(i.e.beginningoffirstbitoffirstpacket)ofthis
mega-frameM+1.
maximum_delay:themaximum_delaycontainsthetimedifferencebetweenthetimeofemissionofthestartofmega-
frameM+1oftheDVB-Tsignalfromthetransmittingantennaandthestartofmega-frameM+1attheSFNadapter,
asexpressedbythevalueofitssynchronization_time_stampintheMIP .Thevalueofmaximum_delayshallbelarger
M
thanthesumofthelongestdelayintheprimarydistributionnetworkandthedelaysinmodulators,powertransmitters
andantennafeeders.Theunitis100nsandtherangeofmaximum_delayis0x000000-0x98967F,thisequalsa
maximumdelayof1second.
tps_mip:thetps_mipconsistsof32bits,P-P .TherelationshipbetweentheTPSasdefinedinEN300744[2]and
0 31
tps_mipasdefinedinthepresentdocumentisdescribedintable3.
ETSI