1、Mobile broadcast solution and implementation scenarios landscape Version 0.1FuTURE Forum 5G Broadcast and Video WG2023/12/5移動廣播技術與應用場景Abstract01 Mobile broadcast landscape and use cases.02 Use case and requirementIntroduction to use casesSummary of use cases03 Analysis of broadcast technologiesDVB-H

2、LTE eMBMSLTE SC-PTM5G Terrestrial BroadcastNR MBSTechniques comparison04 Mapping between use cases and techs05 5G Broadcast trials landscape06 Forward looking of future broadcast serviceReferenceAcknowledgements0102030306070708091011121315171819-Abstract-Traditional broadcasting services and technol

3、ogies developed with radio and television,and at that time,broadcasting applications were mainly the transmission of audio and video.The broadcasting technology was also correspondingly focused on the use of wireless frequencies to support audio and video transmission.With the devel-opment of wirele

4、ss communication and the Internet,current broadcasting applications have gone far beyond the transmission of audio and video,and new application scenarios such as multicast,groupcast,and data download have emerged.With the rise of smartphones,there are also interactive radio applications.The corresp

5、onding broad-casting technology has also been developed,and there have been technological evolutions such as analog to digital and full IP content in the traditional broadcasting standard system,and broadcasting technology for mobile terminals has also been commercially verified.The mobile communica

6、tion standard body has also successively developed MBMS and other technologies to support various applications since 2000.In recent years,there have been several trends in broadcasting applications.“Everyone Connected”is expected for the public services such as emergency alert.With the growing of sm

7、art-phones,the number of mobile phone users has outnumbered the population,that is,everyone has at least one mobile phone.Smartphones have also become the best receiving terminal for public services such as emergency alert.In the event of an earthquake,flood and other disasters,the government disast

8、er relief information would be sent to the people as soon as possible through broadcasting,therefore the victims can be rescued in time and the losses caused by the disaster can be reduced.At present,the governments of China,Europe,the United States,Brazil,India,and other countries are promoting the

9、 technical verification of public emergency services based on the High-Tower broadcasting.Watching live broadcasts of hot sports games and variety shows with mobile phones,pads and other mobile terminals becomes popular.With the commercial deployment of 4G and 5G,and Internet Content Provider(OTT)to

10、 pay the data package for the subscribers,more and more users watch live videos on mobile terminals.In recent years,hot events have attracted more than 10 million users to watch online.Interactive broadcasts such as e-commerce have changed user consumption behaviors.During the epidemic,e-commerce wi

11、thout going to shopping malls and supermarkets has developed greatly,and there has been a“super live broadcast”with a single live broadcast of more than 100 million CNY.Users watch live content through broadcasting and placing the order via unicast.This new application has promoted the development o

12、f broadcast-ing technology and has promoted the development of IP layer technologies such as WebRTC.It is expected that the use of physical layer broadcasting technologies such as 5G broadcasting will greatly reduce the live broadcast cost of OTT platforms in the future.To adapt to these new applica

13、tions,standards organizations such as 3GPP have specified 5G High-Tower broad-casting,NR MBS,etc.These technologies are optimized for different application scenarios to achieve the best use effect.This report summarizes the main mobile broadcasting and multicast application scenarios and sorts out t

14、he technical requirements of each scenario.Subsequently,some of the technical features of mobile broadcasting were introduced.Combined with the technical requirements of each scenario,the technical solutions suitable for each application scenario are summarized for the reference.In Chapter 5,this re

15、port describes the current 5G broadcast trials and progress of various broadcast operators and the industry.Finally,this paper reviews the current highlighted broadcast applications,and looks forward to promoting the development of technology as more novel broadcast applications emerge./01Traditiona

16、l broadcasting services and technologies have been developed with audio and television,as the original broadcasting applications were mainly the transmission of sound and video.The broadcasting technology correspondingly focused on the use of wireless frequencies to support audio and video transmis-

17、sion.With the development of wireless communication and the Internet,as well as the widespread popularity of mobile phones,around 2005,the industry generally believed that the use of smart phones or handheld terminals to directly receive TV signals and watch live TV programs such as sports events at

18、 any time was the next possible killer application.Traditional radio and television industry organizations have successively developed standards for mobile TV and have launched commercial use around the world,mainly supporting applications such as live TV and live advertising.At the same time,3GPP h

19、as also specified mobile broadcast-ing standards based on mobile communication networks to support scenarios such as radio and television,data download,and group communication.In recent years,with the reduction of smartphone and mobile network tariffs,there have been several trends in broadcasting a

20、pplications:“Everyone Connected”is expected for the public services such as emergency alert.With the growing of smartphones,the number of mobile phone users has outnumbered the population,that is,everyone has at least one mobile phone.Smartphones have also become the best receiving terminal for publ

21、ic services such as emergency alert.In the event of an earthquake,flood and other disasters,the government disaster relief information would be sent to the people as soon as possible through broadcasting,therefore the victims can be rescued in time and the losses caused by the disaster can be reduce

22、d.At present,the governments of China,Europe,the United States,Brazil,India,and other countries are promoting the technical verification of public emergency services based on the High-Tower broadcasting.Watching live broadcasts of hot sports games and variety shows with mobile phones,pads and other

23、mobile terminals becomes popular.With the commercial deployment of 4G and 5G,and Internet Content Provider(OTT)to pay the data package for the subscribers,more and more users watch live videos on mobile terminals.In recent years,hot events have attracted more than 10 million users to watch online.In

24、teractive broadcasts such as e-commerce have changed user consumption behaviors.During the epidemic,e-commerce without going to shopping malls and supermarkets has developed greatly,and there has been a“super live broadcast”with a single live broadcast of more than 100 million CNY.Users watch live c

25、ontent through broadcasting and placing the order via unicast.This new application has promoted the development of broadcasting technology and has promoted the development of IP layer technologies such as WebRTC.It is expected that the use of physical layer broadcasting technologies such as 5G broad

26、casting will greatly reduce the live broadcast cost of OTT platforms in the future.This section provides a preliminary summary of the current mobile broadcasting application scenarios for analysis in subsequent chapters.Mobile broadcast landscape and use cases.01/02Use case and requirement02For vari

27、ous mobile broadcasting application scenarios are different,this section summarizes and intro-duces each application scenario and summarizes the corresponding requirements.1.Introduction to use casesEmergency broadcasting is to transmit emergency information to the public through broadcasting techno

28、logy during the public emergencies(natural disasters,accident disasters,public health events and social security incidents).As a rapid and fast information transmission channel and platform,emergency broadcasting transmits disaster alerts or early warning information of disasters to the mass in the

29、first time.The people would be informed with the danger at the first time and get guidance on how to evacuate and avoid danger,so as to minimize the loss of life and property.5G broadcasting also support data broadcast,which can push useful information such as disaster relief information and electro

30、nic maps in the event of a disaster.As one of the revelations of the 2008 Wenchuan earthquake,cable television networks may be forced to interrupt their services in the event of natural and man-made disasters,but terrestrial digital television broadcasting can play an excellent role as an emergency

31、system.When the Changning earthquake occurred in Yebin,Sichuan Province on June 17,2019,the earthquake early warning system issued an early warning to Yibin City 10 seconds in advance,Bijie City,Guizhou Province,124 kilometers away from the epicenter,and Chengdu City,Sichuan Province,61 seconds in a

32、dvance,through radio,television,mobile phones,and special earthquake early warning terminals.In 2018,NRTA promulgated industry technical standards such as GD/J 083-2018 Emergency Broadcast-ing Platform Interface Specification and GD/J 082-2018 Emergency Broadcasting Message Format Specifica-tion,etc

33、.,to define the interface and message format of emergency broadcasting platforms.In August 2020,the Office of the China Earthquake Administration and the General Office of the State Administration of Radio and Television jointly issued the Pilot Work Plan for Earthquake Early Warning Infor-mation Br

34、oadcasting(Emergency Broadcasting).The Plan thoroughly implements the spirit of General Secretary Xi Jinpings important instructions on promoting the construction of the earthquake early warning system and the construction of smart radio and television,explores the establishment of an earthquake ear

35、ly warning emergency broadcasting coordination mechanism through pilot exploration,promotes the docking of the emergency broadcasting system and the earthquake early warning system,and realizes the broadcast of earthquake early warning information through the emergency broadcasting system.On Februar

36、y 14,2020,President Xi Jinping pointed out that it is necessary to innovate and improve major epidemic prevention and control measures from the perspective of institutional mechanisms,improve the national public health emergency management system,and improve the ability and level of response to emer

37、gencies.It is necessary to achieve the combination of peacetime and wartime,make up for shortcom-ings,strengthen the manifestation of government,thoroughly publicize the major decisions and arrange-ments of the Party Central Committee,fully report on the effectiveness of the joint prevention and con

38、trol measures of all regions and departments,widely popularize scientific protection knowledge,and increase publicity and education on the law on the prevention and treatment of infectious diseases.Emergency services are a free,universal service that needs to be delivered to everyone in coverage in

39、a timely and accurate manner.Therefore,it is not mandatory that endpoints must pay to be a user of a network to receive emergency alerts.Public emergency services/03Traditional television programming,also known as linear television,is the traditional television medium that transmits content via sate

40、llite,cable,or wireless.The linear TV is that most of the content is recorded in advance,and the broadcast order is pre-defined,and the broadcast program list is usually distributed to users in advance.The term linear comes from the linear content delivery method.In other words,the content is stream

41、ed on a predetermined schedule,with all viewers watching at the same time.So,in a broader sense,linear TV can refer to any content that is delivered in this way,regardless of the mode of delivery.In this context,the definition of linear TV can cover broadcast content provided by Internet OTTs,includ

42、ing sporting events.This is in stark contrast to user-driven on-demand streaming,where viewers can access the content according to their preferences and needs.Traditional TV showsIn addition to traditional linear TV,Internet OTT also has many live streaming services.This new kind business can be div

43、ided into two categories:live shows,sports,and other live streaming.The live broadcast of variety sports programs is like the linear TV,both of which are single linear video streams.Live streaming is a new type of unicast and broadcast hybrid service in recent years.The interactive broadcast of the

44、live broadcast includes linear live broadcast and interactive unicast data streams,the former has the same playback characteristics as other linear programs,which are pre-recorded or scheduled,while the interactive data is a typical unicast bidirectional data stream.The most important requirement fo

45、r interactive broadcast-ing is the time alignment between the broadcast and the unicast interactive.From the perspective of business form,e-commerce refers to new sales methods such as online display,consultation and Q&A,and shopping guide promotion through the Internet platform.Manufacturers usuall

46、y use professional platforms to open their own brand live broadcast rooms and bring together a variety of products for live broadcast promotion through celebrity person.On the one hand,e-commerce is interactive and affinity.On the other hand,e-commerce bypasses traditional intermediate channels such

47、 as dealers and can give more favorable prices,realizing the seamless connection between products and consumers.e-commerce attracts consumers attention through reliable and cost-effective product promotion,effectively reduces the cost of trust in the process of consumer selec-tion and promotes shopp

48、ing behavior.In recent years,e-commerce has become a popular phenomenon,from officers and enterprise workers to Internet celebrities,to professional sales,the sales of e-commerce have continued to hit new highs.In the process of a typical live TV broadcast,on the one hand,it is necessary to provide

49、low-latency,high-quality live video distribution for most audiences,and interact with the audience with the help of a two-way network.On the other hand,it can be achieved through the integration of 5G broadcasting and unicast technology and complement each other with traditional cable networks to pr

50、ovide users with more efficient and wide-area access methods.Access to online trading platforms and service supervision mecha-nisms will also become an indispensable part of such businesses.With the commercial use of 4G and 5G,live broadcast platforms provide registered members with the service of p

51、latform payment for data package,user viewing for free streaming,and the number of users who watch live broadcast programs of variety shows and sports through mobile networks has also increased in recent years.Especially for hot events and variety shows,the number of real-time online people has exce

52、eded one million,and the number of online people for head programs has exceeded 10 million.Live streaming on the Internet/04IoT devices usually have a long lifespan and need to update software over the air(OTA)during the life cycle of the terminal.Broadcast can push data including software packages

53、to many terminals through broadcast or multicast,and the terminals can download the corresponding data according to the data type and identity of the push.Different from media transmission,data download requires complete and accurate data to be used correctly at the receiving end,and data transmissi

54、on usually does not have high latency requirements,so data download usually uses FEC and time repetition to ensure data reliability.There are many types of data downloaded using broadcast or multicast,such as electronic maps for navigation,various upgrade software,copyright information for media fil

55、es,and so on.At present,most of these data are transmitted through unicast at the physical layer,and the transmission cost is high.Data downloadsGroupcast is a one-to-many mode of communication between the sender and receiver that allows one or more groupcast sources to send the same message to mult

56、iple receivers.A groupcast source sends a copy of data to a specific groupcast address,which is different from a unicast address in that it does not belong to a specific receiver,but to a group of receivers.A groupcast address represents a group,and all recipients who need to receive groupcast packe

57、ts must join the group to receive the corresponding groupcast content.At present,there are many groupcast contents in mobile communications,such as the cell-level system broadcast information and general control information of the cell.OTT applications also have many scenari-os for groupcast applica

58、tions,e.g.,pushing information,videos and news to subscribers.Trunking communication is a special type of groupcast service.The trunking communication system realizes a multi-user shared multi-channel radio mobile communication system according to the dynamic channel assignment,and each user can ini

59、tiate groupcast to other users in the group.The system is generally composed of terminal equipment,base stations,and central control stations,etc.,and has functions such as scheduling,group calling,priority calling,virtual private network,roaming,etc.Trunking communication has a wide range of applic

60、ations,including government users such as public security and ordinary users such as outdoor tourism.The concepts of groupcast and multicast are basically the same and are the same type of service.Trunking and groupcast services/05According to the use cases and parameters in the previous section,the

61、 use cases and typical applications can be summarized in the following table.2.Summary of use casesEmergency services are a free of charge that need to be delivered to all people in coverage in a timely and accurate manner.Therefore,it is not mandatory to pay or subscribe to a network before access

62、the services and receive emergency alerts.Linear TV means the content is pre-re-corded in advance,and the broadcast order is also set in advance.The content is streamed according to a predetermined schedule,and all viewers watch it at the same time.Live sports events and variety shows are similar to

63、 the linear programming of tradition-al TV stations.The interactive broadcast of live stream-ing includes two data streams,linear live broadcast and interactive data stream,the former is the same as other linear programs,and the interactive data replies on unicast and needs to be synchronized with t

64、he live stream.Data download requires complete and accurate data to be used correctly at the receiving end,and data transmission usually does not have high latency requirements,so data download usually uses FEC and time repetition to ensure data reliability.Multicast is a one-to-many mode of communi

65、cation between the sender and receiver that allows one or more multicast sources to send the same message to multiple receivers.The recipients of multicast packets must join the group to receive the correspond-ing multicast content.Use casesRequirements Typical ApplicationsPublic emergencyservicesTr

66、aditional TV showsLive streaming on the InternetData downloadsTrunking and multicast servicesEarly warning of disasters and emergencies Important Information NoticesTraditional TV showsSports events,variety shows,live broadcastsSoftware updates,map updatesIntercom system,control system/06Analysis of

67、 broadcast technologie03This section describes the mobile broadcasting and multicast standards developed by 3GPP.It is worth noting that there are also mobile TV standards developed by traditional terrestrial digital TV standards organizations,such as DVB-H,CMMB,ATSC-M/H,T-DMB,these technical standa

68、rds have been commercially deployed,but they have basically ended commercial deployment.This chapter also uses DVB-H as an example to briefly describe the design of a mobile broadcasting system.1.DVB-HWork on the DVB-H standard began in 2002 and was published by ETSI in 2004 in the EN 302304 standar

69、d.It is entitled Digital Video Broadcasting(DVB);Handheld Terminal Transmission System(DVB-H).The main purpose of the DVB-H was to improve the terminal power-related problems related to mobile reception that occurred during the early introduction of DVB-T.As a result,the physical layer of DVB-H is e

70、ntirely based on DVB-T but enhanced by the introduc-tion of a new transmission mode.DVB-H is primarily designed to transmit video.The general ISO/OSI reference model is adopted,and the upper layer adopts an all-IP-based container and uses RTP and UDP protocols for transmission.At the data link layer

71、,the MPE(Multi-Protocol Encapsulation)protocol is used to encapsulate IP data,and the signal is divided into time slices and transmitted using the MPEG-2 TS protocol.DVB-H uses the H.264(AVC)protocol defined by MPEG to transmit video streams.The protocol supports two transmission modes,usually using

72、 the main profile to transmit standard-definition video programs and using the high profile to transmit high-definition video streams,where the latter supports a 16:9 video ratio.MPE is the core technology of the DVB-H protocol,which encapsulates IP data as MPE fragments,and adds real-time transmitt

73、ed parameters to the head of the encapsulated block for use by the receiver.At the same time,MPE also works as a translator,connecting the IP data at the upper layer with the DVB structure at the lower layer.At the same layer(data link layer),DVB-H introduces a forward error correction coding mechan

74、ism,known as MPE-FEC.The frames are divided into 255 columns and a variable number of rows,with a maximum number of rows of 1024.Therefore,the maximum FEC frame size is equal to 2 Mbit.The frame is divided into an application data table and an RS encoded data table.The application data table is popu

75、lated with IP packets in columns.If a datagram is larger than a single column,its remaining bits are inserted into the next column.At the end of the table,padding bytes would be added if needed.Then,calculate the RS code by row and populate it into the RS datasheet.Redundant RS data allows the decod

76、er to correct multiple erroneous bits in the application data table.MPE-FEC frames are now transmitted in line by forming MPE sections,creating an interleaving effect that provides stronger error protection against bit errors during transmission.The encapsulated MPE data is transmitted in a time-div

77、ision multi-plexing mode,that is,each time slice transmits one MPE data block,and then the transmission will pause the DeltaT time and be transmitted by other program channels during the pause time.In this way,TDM trans-mission of multiple program channels can be realized.Using the TS data stream pr

78、otocol defined by MEPG-2,DVB-H data and DVB-T data streams can be multiplexed in a single data channel to make full use of the channel.DVB-T defines two transmission modes,2K mode covers 17km and can serve high-speed mobile terminals within the coverage,8K mode covers 67km and can serve slow-moving

79、terminals,and DVB-H defines a new 4K mode that can cover 33km and the terminal has a medium moving speed.Overall,DVB-H is designed based on DVB-T and is a superset of DVB-T.It basically follows the packaging and trans-mission protocol of DVB-T and has a new transmission mode to achieve more balanced

80、 coverage./07LTE Rel-9 establishes the eMBMS standard,which provides mobile operators with the opportunity to upgrade and deploy broadcast networks using existing base stations.In the core network test,two new network entities were intro-duced into the LTE broadcast system:the MBMS GW and the BM-SC(

81、Broadcast Multicast Service Center).2.LTE eMBMSThe resource scheduling and configuration of eMBMS uses SIB system messages,including:SIB1:used to schedule SIB2 and SIB13 SIB2:MBSFN subframe configuration list SIB13:Configure PMCH and MCS for PMCH transmission.The MBSFN subframe is developed for sing

82、le-frequency network broadcasting,and the OFDM symbols use an extended cyclic prefix(CP)to counter the inter-symbol interference generated during single-frequency network trans-mission.Due to the extended CP of the symbols,each MBSFN subframe includes 12 symbols,which is two fewer than the number of

83、 symbols in the normal LTE subframe.Figure 1 MBSFN subframe configuration in a FDD frame BM-SC provides broadcast and multicast users with the following features:Member functions Session and Transmission function;Proxy and Transport function;Service Announcement function;Security function.Content sy

84、nchronization for MBMS in E-UTRAN for broadcast mode.Header compression for Mission Critical services using MBMS in E-UTRANThe MBMS GW is the functional entity used for broadcasting.It provides interfaces for entities bearing with MBMS through SGi-mb(User Plane)reference points and SGmb(Control Plan

85、e)reference points,assigns IP addresses,and assigns IP multicast of MBMS user plane data to the RAN nodes.eMBMS defines broadcasting service areas and uses different broadcasting IDs in different broadcasting service areas to provide different broadcasting services and realize broadcasting according

86、 to regions.Within the same broad-cast area,the broadcast base stations support SFN(Single Frequency Network),so they need to be synchronized in time and use the same MBSFN configuration.To better support broadcasting services,operators can configure the number of MBSFN sub-frames according to servi

87、ce needs and can configure up to 6 MBSFN sub-frames in a wireless frame,and the reserved 4 common sub-frames can transmit important information such as system synchronization./08SC-PTM is a single-cell multicast communication,which is mainly designed for multicast scenarios such as trunking communic

88、ation.eMBMS already supports multicast communication in the service architecture and upper-layer proto-cols,but due to the close distance between the terminals of multicast communication,a large number of base stations at the air interface are not required to form an SFN.To improve the resource util

89、ization efficiency of air interfaces,SC-PTM designs a physical layer multicast solution based on Normal CP(NCP).Compared with the multicast subframe using ECP,which has only 12 symbols in one slot,the multicast subframe using NCP has 14 symbols,which can signifi-cantly improve resource utilization.T

90、he following table compares the two technologies of LTE,and last row is the main differences between SC-PTM and eMBMS:3.LTE SC-PTMSC-PTM also considers the service continuity when the terminal moves,and the service cell will send a list of adja-cent cells that support this feature for the terminal t

91、o reselect and switch over the cell.MBSFN AreaPMCHExtended CPMSI:MCH SchedulingInformationNoNoMCCH over PMCHSIB13Single CellPDSCHNormal CPPDCCH,with group specific C-DRXSC-MCCH over PDSCHSIB20eMBMSSC-PTMRemark for SC-PTMNo SFN gain in multi-cell broad-cast due to CRS based cell-spe-cific scramblingS

92、ame as unicast.Receiving UEs share same SC-RNTIHigh spectral efficiency:9 vs.14 symbols per subframeMore flexibleSupport RRC_IDLE mode receiving.SIB style HARQ could be supported in the future even without feedbackBroadcasts radio bearer configu-ration and session informationContains information for

93、 UE to monitor SC-MCCHItemsBroadcast AreaPhysical ChannelSchedulingHARQ and FeedbackControl ChannelSystem InformationCPIn Rel-11,3GPP enhanced the broadcast service continuity during mobility.In the RRC_IDLE state,the cell re-selec-tion of the terminal is enhanced to ensure that the broadcast can be

94、 received,and the signaling to maintain service continuity is added in the RRC_CONNECTED state to support the update of user service description(USD)and service area,so that the service of the terminal is not affected when the switchover is made./095G Terrestrial Broadcast is a 3GPP Rel-16 project,w

95、hich is based on Rel-14 EnTV project and is optimized for the single-site ultra-large coverage and high-speed mobile terminal reception proposed by broadcast operators.To simplify deployment,5G broadcasting uses part of the core network of eMBMS and redesigns the air interface part.To simplify the n

96、arrative,this section summarizes the features of Rel-14 and 16 as follows:Dedicated broadcast carriers:Using the traditional broadcast operators own broadcast frequency,all resources on this frequency can be used for the transmission of broadcast subframes.The synchronization signal and cell broad-c

97、ast channel necessary for access need to be reconfigured to maximize the use of broadcast subframes to transmit broadcast service information.FTA/ROM:Traditional broadcast operators offer both universal access channels of a public service nature(e.g.,CCTV-1)and charged content(e.g.,HD channels).To e

98、nsure that any user can access the public service channel,users are allowed to directly access system information without authentication and receive broadcast services within the range of pre-configured broadcast service IDs(TMGI,temporary mobile group indication).A variety of OFDM numerology design

99、s consider the wide coverage and high-speed mobile requirements of various types of terminals.The 100s CP supports travel speeds of up to 250Km/h.The 200s CP supports speeds of 120Km/h and single-station coverage of up to 30Km.The 300s CP supports 100Km single cell coverage.Cell Acquisition control

100、Signal(CAS)Reliability Enhancement:Control Channel PDCCH is more redundant transmis-sion,PBCH repetition and system information transmission CFI is used to ensure reliability.The traditional radio broadcasting system has a channel bandwidth of 6MHz,7MHz and 8MHz,but 5G broadcasting follows the 5MHz

101、and 10MHz bandwidth of the 3GPP system.To make full use of the existing broadcast channel to deploy 5G broadcasting,3GPP has increased the number of resource blocks for scheduling,which can flexibly support these three types of bandwidths through scheduling.4.5G Terrestrial Broadcas/10Figure 2 NR MB

102、S architectureMB-UPF is a multicast user plane entity and is usually co-located with unicast UPF,while MB-SMF is a multicast session management entity and is usually co-located with unicast SMF and AMF.Unicast and multicast streams can be combined,separated,and dynamically switched.Sessions are cont

103、rolled by SMF either jointly or separately.The gNB-CU can control different distributed units(DUs)for transmission,and the transmission mode can be multicast(PTM)or unicast(PTP),or it can be transmitted at the same time.To improve the reliability of multicast transmission,NR MBS introduces a feedbac

104、k retransmission mecha-nism.When the UE fails to receive the message,it can send a NAK message to request retransmission,and the DU uses the RLC AM mode for retransmission.NR MBS supports multicast and broadcast transmission at the protocol level,and the following table compares the main air interfa

105、ce features of multicast and broadcast.After commercial investigation in the 4G era,operators believe that it is difficult to achieve profitability by using valuable mobile communication frequencies for broadcast TV programs.In 5G they do not even widely specify a struc-ture like MBSFN subframes,exc

106、ept 60KHz SCS.At the same time,the industry believes that the NR SC-PTM would help operators distribute multicast traffic in hotspot areas and enhance the multicast services for trunking communication.A typical NR MBS application scenario is to provide multi-view real-time video streams for on-site

107、users in the stadi-um,and the audience can see real-time videos from other angles through mobile phones and other terminals.Due to the large number of on-site users,unicast can easily exceed the capacity of the network to transmit data for each user,so multicast is used to transmit multi-view video

108、streams for users of a certain operator in the field.The Rel-17 NR MBS emphasizes that the sub-carrier spacing of the NR physical layer is not changed,and the frame structure of the extended CP is not introduced,so the single-site coverage cannot be too large.The standardization work mainly includes

109、 the following technical features:Define the basic functions of broadcast/multicast for UEs in RRC_CONNECTED state.Specify a group scheduling mechanism to allow the UE to receive broadcast/multicast services,implementing the necessary enhancements required to operate simultaneously with unicast rece

110、ption.Implement dynamic switching between multicast(PTM)and unicast(PTP)and provide service continuity function to the corresponding UE.Provide service continuity support,including mobility.Necessary coordination functions,such as MCE hosting of base stations based on terminal residencies,support SA

111、2-defined business processes for broadcast/multicast.Leverage technologies such as uplink feedback to improve the reliability of broadcast and multicast services to support the reliability levels required by different applications.Study the support of dynamic control of broadcast and multicast trans

112、mission areas within a gNB-DU.Define the basic functions of broadcast/multicast for UEs in RRC_IDLE/RRC_INACTIVE state:Specify the required changes to enable UE to receive point-to-multipoint transmission in the RRC_IDLE/R-RC_INACTIVE state,with the goal of maintaining maximum commonality between th

113、e RRC_CONNECTED state and the RRC_IDLE/RRC_INACTIVE state of the PTM receive configuration.The most important design goal of NR MBS is to dynamically switch the data stream between multicast and unicast.For example,in a hot area,the network switches the unicast stream to the broadcast stream as the

114、number of users watching the live stream increases,or the multicast stream switches to the unicast stream as the users channel deterio-rates.The following figure shows the NR MBS service architecture.5.NR MBS/116.Techniques comparisonThis section summarizes the above technical standards from the fre

115、quency of use and techniques and introduces the commercial situation.VHF,UHF broadcast spectrumIMT spectrumIMT spectrumUHF broadcast spectrumIMT spectrumDVB-HeMBMSSC-PTM5G broadcast(Rel14+Rel-16)NR MBSStandardFrequencyTechniquesCommercializationstatusCommercial network has been shut down.Commerciali

116、zation in India,AustraliaNo commercialization No commercializationNo commercializationThe MPE(Multi-Protocol Encapsu-lation)protocol is used to encapsulate IP data.The signal is divided into time slices,MPEG-2 TS protocol,DVB-H uses the H.264(AVC)protocol defined by MPEG to transmit video streamsHyb

117、rid unicast/MBMS operating model.15 kHz subcarrier 16.7s of extended CP Supports Multi-Cell Transport Only(MBSFN)MBSFN transmits up to 60%of subframesSingle-cell transmission,not single-frequency networkTransmit as a group on PDSCH.The sending base station does not need to be synchronizedDedicated b

118、roadcast spectrum:All resources can be used for broadcast service transmission.ROM:The endpoint receives broadcast services only within the range of standardized or configured TMGI values for system information.Does not require the terminal to use USIM.Using 370Hz,1.25KHz,2.5KHz subcarrier spacing,p

119、rovide ultra single-station coverage of tens of kilometers and support high-speed mobile terminal reception.Support for rooftop and on-board antennas,handheld receiversGroupcast and broadcast are supported,and groupcast is similar to SC-PTM No new OFDM numerologies,and a wide range of SFN is not sup

120、ported.For groupcast data,users can provide feedback on whether it is received correctly.Dynamic switching between multicast and unicast data/12Based on the above analysis of the needs of various use cases,this summary provides a mapping between each use case and broadcast technology.Mapping between

121、 use cases and techs04TechnologiesNotes Linear TVPublic serviceTrunking,Push-2-Talk5G High-TowerBroadcast(3GPP Rel-14/16)5G High-TowerBroadcast(3GPP Rel-14/16)LTE SC-PTM and NR MBSLinear TV is mostly a traditional radio and television system,and the use of large tower broadcasting can make full use

122、of existing facilities and reduce network construction investment and maintenance costs.High Tower Broadcasting can make use of the existing abundant radio and television frequency resources.Making full use of the TV towers can reduce CAPEX and OPEX.According to the national standard GY 5060-2008:Cl

123、assification Standard for Seismic Fortification of Radio,Film and Television Construction Projects,TV towers usually have a higher seismic resistance grade and are more likely to work normally in the event of a natural disaster.Trunking communication is usually concentrated in the range of couple ki

124、lome-ters,and the communication efficiency is higher than that of ultra-long CPs for large-scale broadcasting,and the communi-cation efficiency is higher by using common numerologies(such as 15KHz OFDM).Data download5G High-TowerBroadcast(3GPP Rel-14/16),NR MBS、LTE SC-PTM and eMBMSData download is u

125、sually in a certain area,and the sender pushes specific data to specific terminals,including software packages,traffic lights,videos,etc.Depending on the size of the area,High-Tower broadcasting,or LTE eMBMS technology can be used for a wide range of software upgrades.For a small area of electronic

126、traffic light information,NR MBS and LTE SC-PTM technologies can be used./13R17 NR MulticastR17 NR BroadcastDefinitionWhich UEs can receive service in which RRC state?RAN Architecture UE context in RAN and 5GCRadio bearer type and ReliabilityMulticast MBS session-Multicast MRB:PTM only,PTP only or P

127、TM+PTP configura-tion will be supported.Unicast DRB will be used for the case of unicast PDU session delivery method.Multicast MRB supports L1 HARQ&PTM-PTP leg switching for reliabilityPCell andSCell supportMRB Loss-lessHandover supportServicecontinuityServiceavailabilityThe same service and the sam

128、e specific content data are provided simultaneously to a dedicated set of UEs(i.e.,not all UEs in the multicast service area are authorized to receive the data).Multicast UEs are required to join multicast session via NAS SM procedure to receive multicast service.Only UEs in RRC_CONNECTED state can

129、receive Multicast.Both RAN and CN will keep UE context and which multicast services UE is interest-ed to receive(i.e.,UE context established in network at the time of multicast NAS based session joining procedure).Multicast reception supported in PCell or One SCell with self-scheduling(No simultaneo

130、us PCell+SCell reception)Supported including data forwarding from source to target nodeSupported during handover.Multicast service continuity is based on UE context established in RAN when UE joined multi-cast session.No support for MBS Interest Indication.Service will be provided by gNBs which have

131、 joined multicast via Multicast Session management procedure.The same service and the same specific content data are provided simultaneously to all UEs in a geographical area(i.e.,all UEs in the broadcast service area are authorized to receive the data).There is no need for UEs to join broad-cast se

132、ssion to receive Broadcast service.All UEs,which are registered with 5GC,and broadcast service area can receive broadcast service.UEs in all RRC states can receive.RAN and CN does“not”need to have UE context to provide broadcast service and UEs can receive broadcast service without informing network

133、.Broadcast MBS Session-Broadcast MRBOnly PTM is used for broadcast service delivery.Broadcast MRB does not support L1/L2 reliability.Broadcast reception supported in PCell or One SCell with self-scheduling(No simultaneous PCell+SCell reception)or non-serving cell.No support and Broadcast HO is same

134、as LTE SC-PTM HO.Supported for UEs in RRC_CONNECTED and RRC_IDLE/INACTIVE states mobility.Connected mode broadcast service continuity is based on UE MBS Interest indication.Served by all gNBs in MBS FSAI(Frequency Service Selection Area Identity)Reuses Unicast NG-RAN Architecture and MBS supported b

135、y NR Standalone/MN only in case of NR-DC.Like cell level LTE SC-PTM./145G Broadcast trials landscape05Before MWC-2023,several major European broadcasters signed a Memorandum of Understanding(MoU)to jointly promote the commercial use of 5G High-Tower broadcasting.Participants included France Tlvision

136、,Italian Broadcast-ing Company(RAI),SWR,Dutch Public Broadcasting Corporation(NPO),the Irish Broadcasting Company(RTE)and the Austrian Broadcasting Corporation/Austrian Radio Network(ORF/ORS).The new Champions League season and the Paris 2024 Olympic Games will be broadcast via 5G High-Tower Radio.S

137、tarting from the 5G Today project in Germany in 2018,5G High-Tower broadcasting trials have been carried out in some European countries,as well as China,Brazil,South Korea,Colombia,and other countries®ions.In July 2023,the construction of the 5G High-Tower broadcasting trial network in Chengdu,Si

138、chuan Province will be launched.In September 2023,WWOO-LD TV in the Boston area of the United States also launched an 5G High-Tower broadcast signal.Figure 3 shows the global trial of 5G tower broadcasting.In Europe,the German Bavarian Broadcasting Company,SWR,North German Broadcasting Corporation(N

139、DR),European Broadcasting Union(EBU),Norwegian Broadcasting Corporation(NRK),British Broadcasting Corporation(BBC),ORF/ORS,RAI,Russias Gazprom-Media,Spanish Broadcasting Company(RTVE)and France Tlvisions have demonstrated and verified their radio and television services using 5G tower broadcasting t

140、echnology.In 2017,Germany took the lead in launching the 5G Today project,in December 2018,the 5G tower broadcast signal premiered on the Alpine channel Wendelstein.In March 2019,deploying another tower in Ismaning in the north-ern suburbs of Munich to form SFN,which is the first 5G High-Tower broad

141、cast test network in the world.From 2020 to 2022,SWR,together with Deutsche Tower,Porsche,Mercedes-Benz,etc.,implemented the 5G Media2Go project,built two transmission towers in Stuttgart and Heilbronn and several supplementary point sites,and explored the use of 5G High-Tower broadcasting for the t

142、ransmission of on-board audio and video information.In 2021-2023,NDR and Media Broadcast have built two more towers in the Hamburg area for SFN.R&S is the transmitter manufacturer that has partici-pated in most of the worlds 5G High-Tower broadcast trials.Figure 3 Global Landscape of 5G Broadcast tr

143、ials/15In 2018-2019,almost in sync with 5G Today,NRK also conducted a 5G High-Tower broadcast trial in Selje on the west coast of Norway,which used a transmitter from the Norwegian brand Paneda.In 2018-2019,the BBC led the 5G RuralFirst project,which uses technologies such as 5G High-Tower Broadcast

144、ing to transmit BBC audio broadcasts in rural areas such as the Orkney Islands,which is an exploratory experiment by the British government to solve the problem of radio and television coverage in rural areas.In 2019,ABS,Academy of Broadcast Science,which is the research institute under NRTA,built t

145、he first 5G broadcast test network in China.During the test,it can cover most of the urban area of Beijing through three transmission towers.In October 2019,during the Rio de Janeiro Rock Festival,Globo,the largest broadcast network company in Latin America and Brazil,led a comparative test of diffe

146、rent transmission technologies such as 5G High-Tower broadcasting.In 2020-2021,TOL,which is Columbia Telecommunication research institute verified the 5G High-Tower for terres-trial TV broadcasting in Santiago.In 2020-2021,RAI led the 5G Tour project in Turin aimed at enhancing the tourist experienc

147、e.RAI and its network company,Rai Way,built two transmission towers in Aosta for the SFN verification.In March 2023,Rai Way deployed the 5G High-Tower broadcast in Palermo to transmit VR video.In June 2021,the NTV channel,owned by Russias largest media company,Gazprom-Media,launched a 5G High-Tower

148、broadcast trial together with telecom operator MegaFon.In 2021,the Korean Broadcasting Corporation(KBC)and the Korea Electronics and Communications Research Institute(KEIT)conducted a field trial of 5G High-Tower broadcasting in Seoul.During the Eurovision Song Contest in April-May 2022,EBU organize

149、d SWR/DG/DB,ORS/ORF,TLLlvisions and RAI to use 5G tower broadcasting technology to conduct simultaneous HD live broadcasts in four cities,including Stutt-gart,Vienna,Paris,and Turin,which was the largest trial of 5G tower broadcasting to date.Since 2020,ORF/ORS has built three 5G towers for broadcas

150、ting around Vienna and carried out a series of trials on television service demonstrations.During the Danube Music Festival in Vienna in June 2023 and the MotorGP in Spiel-berg in August,the live broadcast signal of the 5G tower was provided to music fans and moto fans,respectively.For the two conse

151、cutive French Open tennis tournaments in 2022 and 2023,France Tlvision,together with France Telecom and Qualcomm,used 5G High-Tower broadcasting technology to broadcast 4K UHD matches in three cities,including Paris,Toulouse,and Nantes.During the Dutch Radio and Television Show in September 2023,TDF

152、 announced that its pilot channel will gradually replace DVB-T2 with 5G tower radio in 2026-2028,and 5G High-Tower broadcast will be commercialized officially in 2029.From January to March 2023,during the Audiovisual Exhibition(ISE 2023)and the Mobile World Congress(MWC 2023),RTVE,together with Cell

153、nex,R&S and Qualcomm,used 5G tower broadcasting technology to send two sets of TVs such as Canal 24h and La1 and one set of broadcast services such as Radio5 in Barcelona.Since MWC 2020,RTVE and Cellnex have collaborated on several consecutive trials of 5G High-Tower broadcasting technology.In May 2

154、023,the Czech Radio,and Television Network Transmission Company(CRA)launched the second phase of the 5G High-Tower broadcasting trial,adding a new transmission point for networking on the basis of the single point coverage in the Prague area of the first phase of the trial.In August 2023,with the ap

155、proval of NRTA,the 5G Broadcast trial was officially launched in Chengdu.The Academy of Broadcasting Sciences of the State Administration of Radio,Film and Television and the Sichuan Provincial Bureau of Radio,Film and Television are responsible for organizing relevant units of production,learning,r

156、esearch and use to carry out the construction of Chengdus 5G radio and television coverage network,carry out single-frequency network networking technology tests,and test the RF characteristics of 5G radio and television in multiple scenarios,coverage capabilities and mobile reception capabilities u

157、nder different deployment scenarios and parameter configurations.In September 2023,Estonia included the 5G tower broadcast emergency broadcast trial in the CREVEX(Crises Evac-uation Exercise)2023 hosted by the Ministry of Emergency Management,which was completed by Levira and R&S./16Traditional broa

158、dcasting services and technologies have been developed with radio and television,and at that time,broadcasting applications were mainly the transmission of audio and video.Broadcasting technology was also correspondingly focused on the use of wireless frequencies to support audio and video transmiss

159、ion.With the develop-ment of wireless communication and the Internet,current broadcasting applications have gone far beyond the trans-mission of audio and video,and new application scenarios such as multicast,groupcast,and data download have emerged.With the growing of smartphones,there are also int

160、eractive radio applications.The corresponding broad-casting technology has also been developed,and there have been technological evolutions such as analog to digital and contents over IP in the traditional broadcasting standard system,and broadcasting technology for mobile termi-nals has also been c

161、ommercially verified.The mobile communication standard body has also successively developed MBMS and other technologies to support various applications since 2000.In recent years,there have been several trends in broadcasting applications.Everyone Connected”is expected for the public services such a

162、s emergency alert.With the growing of smart-phones,the number of mobile phone users has outnumbered the population,that is,everyone has at least one mobile phone.Smartphones have also become the best receiving terminal for public services such as emergency alert.In the event of an earthquake,flood a

163、nd other disasters,the government disaster relief information would be sent to the people as soon as possible through broadcasting,therefore the victims can be rescued in time and the losses caused by the disaster can be reduced.At present,the governments of China,Europe,the United States,Brazil,Ind

164、ia,and other countries are promoting the technical verification of public emergency services based on the High-Tower broadcasting.Watching live broadcasts of hot sports games and variety shows with mobile phones,pads and other mobile termi-nals becomes popular.With the commercial deployment of 4G an

165、d 5G,and Internet Content Provider(OTT)to pay the data package for the subscribers,more and more users watch live videos on mobile terminals.In recent years,hot events have attracted more than 10 million users to watch online.Interactive broadcasts such as e-commerce have changed user consumption be

166、haviors.During the epidemic,e-commerce without going to shopping malls and supermarkets has developed greatly,and there has been a“super live broadcast”with a single live broadcast of more than 100 million CNY.Users watch live content through broadcast-ing and placing the order via unicast.This new

167、application has promoted the development of broadcasting technology and has promoted the development of IP layer technologies such as WebRTC.It is expected that the use of physical layer broadcasting technologies such as 5G broadcasting will greatly reduce the live broadcast cost of OTT platforms in

168、 the future.To adapt to these new applications,making full use of existing broadcasting technologies and developing new technologies accordingly has become a hot topic of technology.At the same time,various broadcast operators and the industry are also actively promoting the commercial maturi-ty and

169、 deployment of 5G broadcasting and other technologies through broadcast technology experiments.It can be expected that as more commercial applications of broadcasting emerge and mature,broadcasting technology will further evolve to support these new applications.From a technical point of view,in add

170、ition to the physical layer broadcast described in this article,there is also a multicast and groupcast technology that is widely used at the IP layer.IP multicast technology continues to evolve to carry higher bitrate and higher concurrent video services more efficiently.IP multicast technology ena

171、bles real-time data distribution from a single point to multiple points in an IP network.IP multicast protocols can be divided into multi-cast member management protocols and multicast routing protocols.The multicast member management protocol applies to the host and routing devices,including IGMP a

172、nd MLD multicast protocols,and the multicast routing protocol applies to routing devices,including PIM,MVPN,and BIER multicast protocols.IGMP multicast technology is widely used in IPTV services,effectively reducing the bandwidth requirements of 4K and 8K UHD live streaming services.With the evoluti

173、on of IP networks to SRv6 and SDN,technologies such as BIER multicast are also evolving to adapt to the continu-ous explosion of services such as e-commerce on the public Internet.Forward looking of future broadcast service06/17-Reference-1.FuTURE Forum 5G broadcast and video WG,5G broadcast Use Cas

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177、V1.2.1,Digital Video Broadcasting(DVB);DVB-H Implementation Guidelines.European Telecommunication Standards Institute,2005.9.Patrik Hummelbrunner and Werner Robitza,DVB-H:Technical Overview and Design Requirements for Mobile Television Broadcasting,hummelbrunner-robitza-dvbh.pdf(slhck.info),200910.R

178、eport ITU-R BT.2526-0 BT Field trials of terrestrial multimedia mobile broadcasting systems,September 2023.11.國家廣播電視總局 工作動態 5G廣播電視試驗（成都）正式啟動()，2023年8月/18-Acknowledgements-In the process of preparing this report,we have received strong support and contributions from experts from the following univers

179、ities,research institutes and companies,and we would like to express our sincere gratitude on the completion of this report.ABS-廣播電視科學研究院 Ateme Baicells 佰才邦 Beijing Radio and Television Station-北京廣播電視臺 CBC 中廣傳播 Communication University of China 中國傳媒大學 Communication University of Shanxi 山西傳媒學院 Hisens

180、e 海信 Keysight 是德科技 MiGu 咪咕 Qualcomm 高通 Quectel 移遠 Samsung-三星 Shanxi Cloud Media Development Co,Ltd 山西云媒體發展集團有限公司 Shanxi Radio and TV Media Group Co.Ltd 山西廣播電視傳媒（集團）有限公司 Shanghai Jiaotong University 上海交通大學 Syntronic(Beijing)technology R&D center Co.Ltd-新拓尼克（北京）科技研發中心有限公司 vivo 維沃 Xinjiang Broadcaster-

181、新疆廣電網絡 ZTE 中興通訊股份有限公司張 宇（Yu Zhang）、夏志平（Zhiping Xia）、肖婧婷（Jingting Xiao）陳朋奕（Ben Chen）、Mickael Raulet云翔（Xiang Yun）、李娜（Na Li）、周明宇（Mingyu Zhou）程宏（Hong Cheng）、王麒 （Qi Wang）蒲珂（Ke Pu）尹航（Hang Yin）、王非非（Feifei Wang）、林濤（Tao Lin）、史萍（Ping Shi）石東新（Dongxin Shi）、李朝暉（Chaohui Li）、潘達（Da Pan）劉鵬（Peng Liu）、耿小芬（Xiaofen Geng

182、）宋一迪（Yidi Song）封翔（Xiang Feng）李琳（Lin Li）、徐嵩（Song Xu）、聶國梁（Guoliang Nie）曹一卿 (Yiqing Cao)、Thomas Stockhammer、李儼（Yan Li）、杜志敏（Zhimin Du)姚立（Li Yao)、滕霞（Tanya Teng）吳越（Yue Wu）王斌（Bin Wang)、邵文衛（Wenwei Shao)、王俊莉（Junli Wang）任曉瑛（Xiaoying Ren）何大治（Dazhi He)、徐胤（Ying Xu）王瑞明（Ray Wang）張元（Yuan Zhang）陳常偉（Changwei Chen）劉耀東（Yaodong Liu）/19