e-MBMS in LTE

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e-MBMS in LTE

  1. 1. Teleca White PapersSolution area: e-MBMS in LTEIncreasing broadcast and multicast servicecapacity and quality using LTE and MBMSW I T H T H E I N T R O D U C T I O N O F L O N G T E R M E V O L U T I O N ( LT E ) , T H E 4 GT E C H N O L O G Y G I A N T, M B M S H A S B E C O M E A N AT T R A C T I V E O P T I O N F O RO P E R ATO R S W H O WA N T TO I N C R E A S E B A N D W I D T H C A PA C I T Y A N D I M P R O V ES E RV I C E Q U A L I T Y W I T H O U T H AV I N G TO M A K E A C O S T LY I N V E S T M E N T I NR E C E I V E R H A R D WA R E O R N E T W O R K I N F R A S T R U C T U R E . I N T H I S W H I T EPA P E R , W E E X P L O R E T H E T E C H N O L O G Y A N D D E M O N S T R AT E WAY S I NW H I C H I T M E E T S T H E N E E D S O F TO D AY ’ S B R O A D C A S T A N D M U LT I C A S TS E RV I C E P R O V I D E R S .
  2. 2. Introduction Many operators have already launched mobile TV services to their subscribers for watching television on their mobile devices. Operators are currently using the streaming option over point- to-point connections for their mobile TV services. Unfortunately this point-to-point stream- ing option is limited when deploying any mass media services, including mobile TV, in a very large-scale market. This led both the 3rd Generation Partnership Project (3GPP) and the 3GPP2 working groups to kickstart the work item on Broadcast/Multicast technology. The 3GPP named the work item as MBMS (Multimedia Broadcast Multicast Services) and 3GPP2 named the work group as BCMCS (Broadcast Multicast Service) MBMS introduces point to multipoint communication where data packets are simultaneously transmitted from a single source to multiple destinations. The term “Broadcast” here refers to the normal transmission of content such as TV services and radio services. “Multicast” refers to transmission of content to a specific group of users: for example, a group of shareholders watching stock activity. A multicast-enabled network ensures that the content is solely distributed over those links that are serving receivers belonging to the corresponding multicast group. This makes MBMS a very resource-efficient way of delivering services to larger user groups. Santhanaraj Muthusamy February 2011TELECA WHITE PAPER 2
  3. 3. e - M B M S i n LT EWhy MBMS?At present, mobile TV services are delivered over point-to-point connections. As a consequence, acontent server that delivers content to several users at a time must establish and maintain a separatepoint-to-point connection for each recipient. This approach works well for low to moderate numbersof subscribers, but does not scale well as the number of subscribers increases. Imagine, for instance,a popular ringtone service that synchronizes a list of top five ringtones in a user’s phone. Further, letus assume that 50,000 users subscribe to the service and each user connects at an average wireless linkspeed of 128Kbps, and that each music file is approximately 3MB in size. Each time a new title entersthe top-five list it must be delivered to all 50,000 subscribers. Assuming the content server can handleonly 1,000 parallel connections at a time, it will take more than 2.5 hours to deliver one ringtone to all50,000 users. During this period, the server will generate continuous 128Mbps outgoing traffic. Notealso that 50,000 subscribers is a relatively small number compared to the total market of potential sub-scribers per operator.Next consider how much capacity will be consumed by real-time services such as mobile TV. In thiscase, serializing will not work. Instead, a mobile TV service with 50,000 subscribers requires a serverfarm that can handle 50,000 simultaneous connections. Although this is technically possible, it is notan economical solution. Furthermore, the service would generate a tremendous amount of outboundtraffic when many subscribers use it at the same time. Because spectrum is a limited and expensiveresource, the radio access network – in particular, the wireless link – can also easily become a bottle-neck if numerous recipients of the same service are located in the same cell. Imagine, for example, asoccer stadium where fans use their mobile phones to monitor parallel games, much the same way theycurrently use transistor radios. In this case, the use of point-to-point radio bearers would be very inef-ficient, if not prohibitive. Therefore, there is a clear need for new point-to-multipoint radio bearers thatcan support broadcast/multicast services more efficiently.MBMS in GPRS/EDGEIn GSM systems, MBMS uses GPRS and EDGE modulation and coding schemes (that is, CS1-4 andMCS1-9). MBMS also uses the GPRS and EDGE packet data channel (PDCH) for point-to-multipointtransmissions, and the Radio Link Control/Medium Access control (RLC/MAC) protocols on layer 2.As for point-to-point transmissions, MBMS also supports multi-slot operation. In this case, the radionetwork may use up to four timeslots per MBMS session. Early simulations have shown that the per-TELECA WHITE PAPER 3
  4. 4. e - M B M S i n LT Eformance of a straightforward MBMS bearer implementation is not satisfactory. Therefore, to increaseperformance, two enhancements have been introduced: 1. RLC/MAC with automatic repeat request (ARQ): also called packet downlink Ack/Nack (PDAN)mode. In this mode, session feedback is provided from up to 16 terminals in a given cell. This way,the RLC data blocks that a terminal did not receive correctly are rebroadcasted over the MBMS radiobearer so that the terminal can use incremental redundancy techniques.2. RLC/MAC without ARQ: also called blind repetition mode. In this mode, RLC blocks are repeateda pre-defined number of times, using an incremental redundancy technique, before the next RLC blockis sent. MBMS terminals will probably be based on existing EDGE hardware, with a software updateto support MBMS signaling procedures. In GSM, MBMS radio bearers can be multiplexed with GPRS/EDGE data flows, even on the same timeslots. One deployment scenario might be to activate MBMSin dense areas where EDGE is deployed: in areas without EDGE, MBMS can be provided over point-to-point GPRS. One other deployment scenario might entail phasing in levels of functionality: forexample, starting with MBMS broadcast and adding MBMS multicast. This would save capacity in cellsthat do not have users asking for the service.MBMS in WCDMAIn WCDMA, MBMS reuses existing logical and physical channels to the greatest possible extent. Infact, the implementation in WCDMA requires only three new logical channels and one new physicalchannel. The new logical channels are: • An MBMS point-to-multipoint control channel (MCCH), which contains details concerning ongoing and upcoming MBMS sessions; • An MBMS point-to-multipoint scheduling channel (MSCH), which provides information on data scheduled on MTCH; and • An MBMS point-to-multipoint traffic channel (MTCH), which carries the actual MBMS application data.The new physical channel is the MBMS notification indicator channel (MICH) by which the networkinforms terminals of available MBMS information on MCCH. An important characteristic of MBMSin WCDMA is that the MBMS radio transmission cost is independent of the number of subscribersTELECA WHITE PAPER 4
  5. 5. e - M B M S i n LT Ein the cell. With WCDMA MBMS technology (3GPP Rel-6), one 5MHz cell carrier can potentiallysupport 16 point-to-multipoint MBMS channels at a user bit rate of 64Kbps per channel, for a single-receive-antenna terminal. One important aspect of MBMS is flexibility. MBMS can be set to use only aportion of a cell carrier, leaving the rest for other services such as regular voice and data. The MBMSportion comprises a variable number of MBMS radio bearers. Moreover, each radio bearer can have adifferent bit rate. Although MBMS supports user bit rates of up to 256Kbps, given current handheldterminal display sizes and resolutions, 64Kbps is adequate for a news channel application and 128Kbpsfor a sports channel application.Introduction of IMBIntegrated Mobile Broadcast (IMB) is a part of 3GPP’s Release 8 standard, providing capabilities forbroadcast services similar to the broadcast element of MBMS in 3G TDD bands. In some markets, thedemand for linear TV, video and other non-linear multimedia content is increasing rapidly. At the sametime, most operators are seeing huge growth in wireless broadband, which will soon lead to congestionin their 3G networks. Because of this, mobile network operators are considering the deployment of abroadcast-capable mobile technology to alleviate emerging capacity constraints. IMB can be used toenable broadcast transmission using TDD spectrum allocations that are already held by many operatorsthat have 3G licenses.IMB is a technology, defined as a part of the 3GPP Release 8 standard, which enables spectrally-effi-cient delivery of broadcast services using TDD radio techniques. This is achieved using technical speci-fications that are greatly aligned with existing FDD WCDMA unicast technology, which in turn allowsfor smooth handover between IMB delivery and unicast. One of the key advantages of IMB is that itcan be deployed within unpaired TDD spectrum bands held by operators in some parts of the world.To date, TDD spectrum has been largely unused by these operators. IMB can offer capacity relief tothe FDD channels by allowing TDD spectrum to be used for the deployment of broadcastapplications. Support for existing Rel. 7 MBSFN and other TDD services has been incorporatedwithin IMB through the reuse of the definitions of TDM pilots used in FDD MBMS frame and slotstructure. This results in the increased spectral efficiency of MBMS services and a reduction in thefunctional complexity in the user terminal, which in turn will result in lower power consumption andextended terminal battery life. IMB may also serve as the basis for the standardisation of eMBMS – anevolution of MBMS to be supported over Long Term Evolution (LTE) – offering a smooth migrationof IMB services towards LTE-based deployments. The key challenge for IMB is the support withinTELECA WHITE PAPER 5
  6. 6. e - M B M S i n LT Ehandsets for both FDD and TDD frequencies, but this is expected to increase as these new services aredeployed by operators.e-MBMS – MBMS in LTEEven though MBMS was introduced in Release 6 specifications of 3GPP, trials of MBMS services hasbeen conducted by a small number of operators so far. However, with the introduction of LTE, thegiant of 4G technology, MBMS is now an attractive option for operators who finally have enoughbandwidth to cope with demand. After deploying LTE, the next logical step, according to most opera-tors’ roadmaps, is to deploy e-MBMS in their network.An initial LTE design requirement was to support an enhanced version of MBMS compared to UMTSRelease 6. The targets included cell-edge spectrum efficiency in an urban or suburban environment of1 bps/Hz – equivalent to the support of at least 16 Mobile TV channels at around 300Kbps per chan-nel in a 5 MHz carrier. This is only achievable by exploiting the special features of the LTE OFDM airinterface in a Single Frequency Network mode. It was also recognized that the user experience is notpurely determined by the data rate achieved, but also by other factors, such as the interruption timewhen switching channels. This has implications for the design of the MBMS control signaling, whichis also being extensively redesigned for LTE.e-MBMS- SFN The feature in LTE to exploit the OFDM radio interface to transmit multicast or broadcast data as amulticell transmission over a single-frequency synchronized network is termed as MBSFN: MultimediaBroadcast Single Frequency Network. In MBSFN operation, MBMS data is transmitted simultaneouslyover the air from multiple, tightly time-synchronized cells. A UE receiver will therefore observe mul-tiple versions of the signal with different delays, due to the multicell transmission. Provided that thetransmissions from the multiple cells are sufficiently tightly synchronized for each to arrive at the UEwithin the cyclic prefix at the start of the symbol, there will be no Inter Symbol Interference (ISI). Ineffect, this makes the MBSFN transmission appear to a UE as a transmission from a single large cell,and the UE receiver may treat the multicell transmissions in the same way as multipath components ofa single-cell transmission without incurring any additional complexity. The UE does not even need toknow how many cells are transmitting the signal.TELECA WHITE PAPER 6
  7. 7. e - M B M S i n LT EThis Single Frequency Network reception leads to significant improvements in spectral efficiency com-pared to UMTS Release 6 MBMS, as the MBSFN transmission greatly enhances the Signal to Interfer-ence Plus Noise Ratio (SINR). This is especially true at the cell edge, where transmissions which wouldotherwise have constituted inter-cell interference are translated into useful signal energy – hence thereceived signal power is increased at the same time as the interference power being largely removed.e-MBMS DefinitionsMBSFN Synchronization AreaAn area of the network where all eNodeBs can be synchronized and perform MBSFN transmissions.MBSFN Synchronization Areas are capable of supporting one or more MBSFN Areas. On a givenfrequency layer, an eNodeB can only belong to one MBSFN Synchronization Area. MBSFN Synchro-nization Areas are independent from the definition of MBMS Service AreasMBSFN Transmission or a transmission in MBSFN modeA multicast transmission technique realised by transmission of identical waveforms at the same timefrom multiple cells. An MBSFN transmission from multiple cells within the MBSFN Area is seen as asingle transmission by a UE.MBSFN AreaAn MBSFN Area consists of a group of cells within an MBSFN Synchronization Area of a network,which are coordinated to achieve an MBSFN transmission. Except for the MBSFN Area ReservedCells, all cells within an MBSFN Area contribute to the MBSFN Transmission and advertise its avail-ability. The UE may only need to consider a subset of the MBSFN areas that are configured: i.e., whenit knows which MBSFN area applies for the service(s) it is interested in receiving.MBSFN Area Reserved CellA cell within a MBSFN Area that does not contribute to the MBSFN transmission. The cell may beallowed to transmit for other services, but only at restricted power on the resource allocated for theMBSFN transmission.TELECA WHITE PAPER 7
  8. 8. e - M B M S i n LT ESynchronisation SequenceReserved Cell MBSFN Area A cell within a MBSFN Area which does not contribute to the MBSFNEach synchronizationThe cell may be allowed to PDU) contains a timestamp that at restricted start Transmission. Protocol Data Unit (SYNC transmit for other services but indicates the power on the resource allocated for the MBSFN transmission.time of the synchronisation sequence. For an MBMS service, each synchronisation sequence has thesame duration, which is configured in the BM-SC and the MCE. Synchronisation Sequence Each SYNC PDU contains a time stamp which indicates the start time of the synchronisation sequence. For an MBMS service, each synchronisation sequence hasSynchronisation Period the same duration which is configured in the BM-SC and the MCE.The synchronisation period provides the time reference for the indication of the start time of each syn- Synchronisation Periodchronisation sequence. The timestamp provided in each SYNC PDU is a relative value which refers to The synchronisation period provides the time reference for the indication of the startthe start time of the synchronisationperiod. The duration ofstamp which is provided in configurable. time of each synchronisation sequence. The time the synchronisation period is each SYNC PDU is a relative value which refers to the start time of the synchronisation period. The duration of the synchronisation period is configurable. MBMS Service Area MBSFN Area MBSFN Area MBSFN Area MBSFN Area Reserved Cell e-MBMS Architecture & Protocol The management of both MBMS content and resources will be performed through a Multicell/Multicast Coordination Entity (MCE), as shown in below mentionedMBMS Architecture & Protocol figure. This is a new node designed to coordinate the transmissions from multipleThe management of both otherwise be difficult to achieve be performed through a Multicell/Multi- cells, which would MBMS content and resources will in the flat architecture of LTE.cast Coordination Entity (MCE), as shown in the the time/frequency a new resources usedto coordi- The role of the MCE includes allocating figure below. This is radio node designed by all eNodeBs in the MBSFN area, ensuring that the same resource blocks are usednate the transmissions from multiple cells; an undertaking that wouldand decidingdifficult to achieve across the whole MBSFN area for a given service, otherwise be the radioin the configuration (modulation role ofcoding scheme). Thus forthe time/frequency radio flat architecture of LTE. The and the MCE includes allocating MBMS the radio scheduling and configuration roles which are normally the responsibility of theresources used by all eNodeBs in the MBSFN area, ensuring that the same resource blocks are used eNodeBs are instead centralized.across the whole MBSFN area for a given service, and deciding the radio configuration (modulationand coding scheme). Thus, for MBMS, the radio scheduling and configuration roles that are normallythe responsibility of the eNodeBs are instead centralized. 5TELECA WHITE PAPER 8
  9. 9. e - M B M S i n LT E MBMS MME GW M3 M1 MCE M2 eNodeBAn additional logical entity called the MBMS Gateway (MBMS GW) is also defined. It receives user- An additional logical entity called the MBMS Gateway (MBMS GW) is also defined.plane MBMS trafficuser-plane MBMS traffic from the Centre (BM-SC), and, inService Centre It receives from the Broadcast/Multicast Service Broadcast/Multicast contrast to non-MBMS(BM-SC), and, in contrast to non-MBMS traffic, hosts the PDCP layer of the user traffic, hosts the PDCP layer of the user plane for header compression used by MBMS data plane for header compression for MBMS data packets for both multicell and single-packetscell transmission. Theand single-cell transmission. The MBMS GW then forwardsto the including both multicell MBMS GW then forwards the user-plane traffic theuser-plane traffic to the eNodeBs. Each eNodeB hosts the RLC and MAC of theofprotocol stack, eNodeBs. Each eNodeB hosts the RLC and MAC layers layers the protocol stack, including the segmentation and reassembly functions. The other functions whichincluding the segmentation and reassembly functions. The other functions which remain to be hosted remain to be hosted by the eNodeB for MBMS mainly relate to single-cell MBMSby the eNodeB for MBMS mainly relate to single-cell MBMS operation. operation. The interfaces between the MBMS logical network entities are as follows:The interfaces between (MBMS GW – network entities are as follows: interface, no control M1 interface the MBMS logical eNodeB): A pure user plane plane application part is defined for this interface and IP multicast is used for point- to-multipoint delivery of user packets for both single cell and multicell transmission.M1 interface (MBMS GW – eNodeB): A pure user plane interface, no is synchronized for multicell The SYNC protocol is used to ensure that content control plane application part is MBSFN transmission. This carries additional information which enables eNodeBs todefinedidentify interface and IP multicast is and to detect packet loss.deliverystringent timing for this the radio frame timing used for point-to-multipoint The of user packets forboth single-cell and multicell transmission. The SYNC protocol apply to ensure that content is syn- requirements of the SYNC protocol would not is used eNodeBs which only transmit MBMS in single cell mode.chronized for multicell MBSFN transmission. This carries additional information which enableseNodeBs tointerface (MCE frame timing andpure control-plane interface which conveys the M2 identify the radio – eNodeB): A to detect packet loss. The stringent timing requirementsof the SYNC protocol would not applythe eNodeBs, which only transmit MBMS in single-cell mode. session control signalling to to eNodeB, adding the necessary radio configuration data for multicell MBSFN transmission. This additional radio configuration data ensures that the RLC/MAC entities located in the eNodeB are configuredM2 interface (MCE – eNodeB): A pure control-plane interface that conveys the session control SCTP appropriately and consistently in order to deliver synchronized content. The signal- protocol is used over the M3 interface to carry the application part.ing to the eNodeB, adding the necessary radio configuration data for multicell MBSFN transmission. M3 interface (MCE – MBMS GW): A pure control plane-interface that carries theThis additional radio configuration data ensures that the RLC/MAC entities located in the eNodeB are session control signalling on the SAE bearer level, including MBMS „Session Start‟configured appropriately and consistently in order to deliver synchronized content. The SCTP protocol and „Session Stop‟ messages. The Session Start message provides the informationis used necessary for the service (including the part. over the M3 interface to carry the application service area over which to deliver the broadcast transmissions, and relevant QoS parameters). The SCTP protocol is used to carry the application part signalling.The MCE may be deployed as a separateTELECA WHITE PAPER 9
  10. 10. e - M B M S i n LT EM3 interface (MCE – MBMS GW): A pure control-plane interface that carries the session control signal-ing on the SAE bearer level, including MBMS ‘Session Start’ and ‘Session Stop’ messages. The SessionStart message provides the information necessary for the service (including the service area over whichto deliver the broadcast transmissions, and relevant QoS parameters). The SCTP protocol is used tocarry the application part signaling. The MCE may be deployed as a separate node: alternatively, the M3interface may be terminated in eNodeBs, in which case the MCE would be considered to be part of aneNodeB and the M2 interface would not exist. node, alternatively the M3 interface may be terminated in eNodeBs, in which case the MCE would be considered to be part of an eNodeB and the M2 interface would not exist.Deployment considerationThis type of deployment does not preclude the termination of an M3 interface in eNodeBs. In this Deployment considerationcase, MCE is considered to be part of eNodeB. However, M2 should exist between the MCE and the It is not precluded that an M3 interface can be terminated in eNodeBs. In this casecorresponding eNodeBs. The following figure depicts two potential deployment alternatives. In the MCE is considered as being part of eNodeB. However, M2 should exist between thescenario depicted on the left, MCE is deployed in aThe following In the scenario on theenvisaged is MCE and the corresponding eNodeBs. separate node. figure depicts two right, MCEpart of deployment eNodeB. the QoS of alternatives. In the scenario depicted on the left MCE is deployed in a separate node. In the scenario on the right MCE is part of the QoS of eNodeB. Contents Contents Provider Provider PDN BMSC PDN MBMS GW Gateway Gateway BMSC SG-imb SGmb SG-imb SGmb MBMS MBMS MME Sm MBMS MBMS MME Sm CP UP CP UP M3 MCE M1 M3 M1 F4 F2 M2 MCE MCE eNB eNB eNB eNB MBMS ClientMBMS Client on mobiles on mobiles User Operations The user‟s actions to control MBMS services are defined as following operations  UE Power on  MBMS client on  MBMS service on  Broadcast service on  Multicast service on  MBMS service offTELECA WHITE PAPER  Broadcast service off 10  Multicast service off
  11. 11. e - M B M S i n LT EUser OperationsThe user’s actions to control MBMS services are defined as following operations  UE power on  MBMS client on  MBMS service on  Broadcast service on  Multicast service on  MBMS service off  Broadcast service off  Multicast service off  MBMS client off  UE power offEach operation initiates specific protocol procedures, such as radio channel establishment and serviceactivation, as portrayed in the following figure. Using the GUI of the MBMS client program, a userselects or de-selects a specific MBMS service. The multicast service activation and deactivation requiresUE-Network signaling, whereas the broadcast service activation and deactivation needs intra-UE signal-ing only. MBMS Control Signaling The 3GPP MBMS specifications do not include interactions between protocol entities in the UE. We design the inter-protocol interactions in the UE. The interactions are implemented with service primitives. The MBMS service primitivesTELECA WHITE PAPER protocol entities have several parameters – „op-type‟, „tmgi‟ and „rab-id‟, between 11 which have values as following. The „op-type‟ indicates an MBMS operation, the
  12. 12. e - M B M S i n LT EMBMS Control SignalingThe 3GPP MBMS specifications do not include interactions between protocol entities in the UE. Wemust design the inter-protocol interactions in the UE. The interactions are implemented with serviceprimitives. The MBMS service primitives between protocol entities have several parameters – ‘op-type’,‘tmgi’ and ‘rab-id’, which have the following values: the ‘op-type’ indicates an MBMS operation; the‘tmgi’ (temporary mobile group identity) indicates the corresponding MBMS service; and the ‘rab-id’indicates the MBMS bearer identifier. - Op-type = {mbms_on, mbms_off, broadcast_act, broadcast_deact, multicast_act, multicast_deact} - Tmgi = service_id + plmn_id - Rab-type = {pdp, mbms}Service AnnouncementFor a user to receive MBMS services, he or she needs to know in advance which MBMS services thenetwork provides and how to receive them. This kind of information, which is described as as metada-ta, is structured as shown in the figure below, and is provided via the service announcement procedure.The service announcement can be realized in several ways, such as MBMS, cell broadcast service (CBS),or HTTP. We use an MBMS file download service for the service announcement. Using the MBMSdownload service, the metadata is broadcast over the entire network periodically. The multicast IP Meta User Service Data Bundle Envelope Meta Data Session Envelope Descripti 1. User (*.xml) on files Service Description Meta Data Session Envelope N.User Descripti Service on files Description When a user initiates the MBMS client program, a FLUTE process is created for receiving the service announcement (metadata files). The metadata files areTELECA WHITE PAPER 12 downloaded with the service announcement and downlink packet rate during the
  13. 13. e - M B M S i n LT Eaddress and UDP port number for the service announcement should be predefined and may be broad-cast over the network contained in RRC System Information Block (SIB) message. The IP address‘ff1e :: ff ’ and UDP port ‘5000’ are used in the service announcement.When a user initiates the MBMS client program, a File Delivery over Unidirectional Transport(FLUTE) process is created for receiving the service announcement (metadata files). The metadata filesare downloaded with the service announcement and downlink packet rate during the service announce-ment. On receiving the metadata files, the FLUTE process stores them on the specified directory. TheMBMS client program parses the stored metadata files and extracts service information (such as chan-nel name, contents name, and service starting time) and then displays them to the user.MBMS User ServicesAn MBMS user service is provided with one or more MBMS bearer services. For simplicity, we willonly consider an MBMS user service composed of one MBMS bearer service in our example. As theMBMS supports two service modes (multicast and broadcast) and two delivery types (streaming and filedownload), we compose four MBMS user services. The following table shows the parameters of theMBMS user services. Service Id Channel Name IP Address Port 1 Multicast — Download IP...1 ###1 2 Multicast — Streaming IP...2 ###2 3 Broadcast — Download IP...3 ###3 4 Broadcast — Streaming IP...4 ###4Video Streaming ServiceWhen a user selects a video streaming service, a VLC process is created with a multicast IP addressand UDP ports specified in the corresponding metadata file. In the 3GPP specification, a maximum384Kbps data rate is possible for the MBMS. In an operator’s test-bed, the video streaming serviceshows data rates of approximately 1Mbps as a result of using Ethernet instead of a radio networkbetween UE and e-NodeB.TELECA WHITE PAPER 13
  14. 14. e - M B M S i n LT E File Download ServiceFile Download Service When a user selects a file download service, a FLUTE process is created with aWhenmulticast IP a file download service, a FLUTE process is created with a multicast IP address a user selects address and UDP ports specified in the corresponding metadata file. The downloaded file contains real-time data written in text, which is displayed onand UDP ports specified in the corresponding metadata file. The downloaded file contains real-time the MBMS client program GUI. The file download service which periodicallydata written in text, which isfiles periodically MBMS service area shows periodical peak in the broadcast same text displayed on the to the client program GUI. The file download service, packet data rate graph.which periodically broadcasts the same text files to the service area, shows a periodical peak in thepacketConclusion: data rate graph. Studies says that 3GPP e-MBMS is going to play a key role in mobile broadcast and multicast capabilities for mass-market deployment of broadcast like services.OMA standardizes the Broadcast /multicast service layer functions.e-MBMS reuses much of the existing radio and core network protocols. There are no major inclusions orCONCLUSION of new layers in the existing protocol stack. This plays a keyrole in the introductionStudies says that 3GPP cost reduction strategies key role in mobile broadcast and multicast capabili- implementation e-MBMS is going to play a for Mobile terminal vendors and network operators. There are several advantages when compared with non-mobile networksties for mass-market deployment of broadcast andand additionalservices. The Open Mobile Alliance which require new receiver hardware broadcast-like investments into network infrastructure. Another important advantage is mobile operators can retain their(OMA) has done much to standardize the Broadcast /multicast service layer functions, enabling more business models because of the small size of e-MBMS cells they possess. Theseamless communication between functions. The fact that e-MBMS reuses much with very fine radio operators can service customize the broadcasting of different content of the existingand core network protocols makes forof particularly smooth integration, including no major inclusions granularity in various group a areas. The introduction of e-MBMS will boost the capacity of existing services. Mobile broadcast also enables operators to offeror introduction of Internet, andthe existing protocol stack. These economies play a keycommon telephony, new layers in TV for mobile (small handheld) devices over a role in theimplementation cost-reduction strategies for mobile terminal move toand network operators. service and network infrastructure. Finally the vendors MBMS based services should deliver a significant enhanced consumer experience both in terms of choice but also in terms of the overall quality of the user experience from fast channele-MBMS offers operators theapotential to boost the capacity of their existing services and improve switching through to much higher quality of streamed video.service delivery without making a costly investment. Unlike non-mobile networks, the implementa- References:tion of 3GPP e-MBMS requires no new receiver hardware or additional investments into network 3GPP TS 36.300 LTE E-UTRAN Overall Descriptioninfrastructure—a23.246 MBMS Architecture of cost and timeDescription 3GPP TS significant advantage in terms and functional savings. Another important advantageis that3GPP TS 25.346 can retain their business models in spite of the Multicast of e-MBMS cells mobile operators Introduction of the Multimedia Broadcast small size Service (MBMS) in the Radio Access Networkthey possess. TSaddition, operators canBroadcast Multicast Service (MBMS) in the GERAN fine 3GPP In 43.246 Multimedia customize the broadcasting of different content with very TeliaSonera, Mobile Broadcast/Multicast Service (MBMS), White Paper, August 10TELECA WHITE PAPER 14
  15. 15. e - M B M S i n LT Egranularity to meet the needs of different sub-groups among their customers. Mobile broadcast alsoenables operators to offer telephony, Internet, and TV for mobile devices over a common service andnetwork infrastructure. Finally, the move to MBMS-based services should deliver a significantly en-hanced consumer experience, both in terms of choice and in terms of the overall quality of the userexperience, including fast channel switching and a much higher quality of streamed video.REFERENCES3GPP TS 36.300 LTE E-UTRAN Overall Description3GPP TS 23.246 MBMS Architecture and functional Description3GPP TS 25.346 Introduction of the Multimedia Broadcast Multicast Service(MBMS) in the Radio Access Network3GPP TS 43.246 Multimedia Broadcast Multicast Service (MBMS) in the GERANTeliaSonera, Mobile Broadcast/Multicast Service (MBMS), White Paper, August 2004J. Ogunbekun and A. Mendjeli, “MBMS service provision and its challenges,” Proc. of the 4th Interna-tional Conference on 3G Mobile Communication Technologies, pp.128-133, June 2003.A. Boni, E. Launay, T. Mienville, and P. Stuckmann, “Multimedia broadcast multicast service - tech-nology overview and service aspects,”Proc. of the 5th IEEE International Conference on 3G MobileCommunication Technologies, pp.634-638, 2004ABBREVIATIONS3GPP 3 rd Generation Partnership project4G Fourth GenerationARQ Automatic Repeat requestBCMCS Broadcast Multicast serviceCBS Cell Broadcast ServiceCS Coding SchemeEDGE Enhanced Data rate for GPRS EvolutionFDD Frequency Division DuplexFLUTE File Delivery over Unidirectional TransportGPRS General packet Radio ServiceTELECA WHITE PAPER 15
  16. 16. e - M B M S i n LT EGSM Global system for Mobile communicationGUI Graphical user InterfaceIMB Integrated Mobile BroadbandISI Intersymbol InterferenceLTE Long Term EvolutionMAC Medium Access ControlMBMS Multimedia Broadcast multicast ServiceMBSFN Multimedia Broadcast Single Frequency NetworkMCE Multicast coordination GatewayMCS Modulation and Coding SchemeMME Mobility Management EntityOFDM Orthogonal Frequency Division Multiple AccessOMA Open Mobile AlliancePDAN Packet data Ack/NAKPDCH Packet Data ChannelPDN Packet Data NetworkQOS Quality of ServiceRLC Radio link controlSCTP Stream Control Transmission ProtocolTDD Time Division DuplexUMTS Universal Mobile Telecommunication systemWCDMA Wideband Code Division Multiple AccessTELECA WHITE PAPER 16

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