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Supported from Rel-9• Shared carrier deployments (TDM on sub-frame level shared with unicast)• Semi-Static MBSFN areas with possible overlap• Downlink only transmission (no feedback channels)
Supported from Rel-10 • Counting of MBMS interested UEs in connected mode• Semi-static activation/deactivation of eMBMS session per MBSFN area
Further work on service continuity is foreseen for Rel-11• Mobility (cell selection/reselection and handover)
Multiplexing of MBMS and unicast is realized in the time domain onlyMCH is transmitted over MBSFN in specific subrames on physical layerMCH is a downlink only channel (no HARQ, no RLC repetitions)• Higher Layer Forward Error Correction (see TS26.346)
A single transport block is used per subframeDifferent services (MTCHs and MCCH) can be multiplexed The MCS of each MCH is fixed in the MBSFN area and selected by the network
Frame structure for shared carriers TDM principle • MBSFN is not transmitted in subframes 0, 4, 5 and 9 (FDD)
and subframes 0, 1, 2, 5, 6 (TDD)• The subframe ratio available for MBMS ranges from 1/320 to 192/320• A 10/40ms pattern repeats over {1, 2, 4, 8, 16, 32}radio frames
Single MBSFN subframe contains single cell control part and MBSFN part
BMSC (broadcast multicast service center): provides functions for MBMS user service initiation and deliveryMBMS-GW (MBMS gateway): broadcasts MBMS packets to each eNB transmitting the service on M1 interfaceMCE (Multi-cell Coordination Entity)• Allocates or not the radio resources used by eNBs in the same MBSFN area• Configures MBSFN subframes for MBMS control and data broadcast• Ensures that the L2/L3 layers in eNBs are well configured for MBSFN operation• Determines the MCS for PMCH
Main referencesFeasibility study for evolved Universal Terrestrial Radio Access (UTRA) and Universal Terrestrial Radio Access Network (UTRAN)http://www.3gpp.org/ftp/Specs/html-info/25912.htmEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2http://www.3gpp.org/ftp/Specs/html-info/36300.htmEvolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation http://www.3gpp.org/ftp/Specs/html-info/36211.htmEvolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specificationhttp://www.3gpp.org/ftp/Specs/html-info/36331.htmEvolved Universal Terrestrial Radio Access Network (E-UTRAN); General aspects and principles for interfaces supporting Multimedia Broadcast Multicast Service (MBMS) within E-UTRANhttp://www.3gpp.org/ftp/Specs/html-info/36440.htmMultimedia Broadcast/Multicast Service (MBMS); Protocols and codecshttp://www.3gpp.org/ftp/Specs/html-info/26346.htm