Multicast-broadcast single-frequency network: Difference between revisions

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'''Multicast-broadcast single-frequency network''' ('''MBSFN''') is a [[Channel (communications)|communication channel]] defined in the [[4G|fourth-generation cellular networking standard]] called [[3GPP Long Term Evolution|Long Term Evolution (LTE)]]. The transmission mode is intended as a further improvement of the efficiency of the [[MBMS|enhanced Multimedia Broadcast Multicast Service]] (eMBMS) service, which can deliver services such as [[mobile TV]] using the LTE infrastructure, and is expected to [[MBMS#Competing technologies|compete]] with dedicated mobile/handheld TV broadcast systems such as [[DVB-H]] and [[DVB-SH]].<ref>{{cite web|title=Long Term Evolution (LTE): A Technical Overview|url=http://www.motorola.com/web/Business/Solutions/Industry%20Solutions/Service%20Providers/Wireless%20Operators/LTE/_Document/Static%20Files/6834_MotDoc_New.pdf|publisher=Motorola Technical White Paper|page=10}}</ref><ref name=Turner>{{cite web|last=Turner|first=Lorraine|title=3G evolution to rival DVB-H, WiMAX - Analysys|url=http://www.totaltele.com/view.aspx?ID=363424|publisher=Total Telecom|accessdate=9 February 2006}}</ref> This enables [[network operator]]s to offer mobile TV without the need for additional expensive [[licensed spectrum]] and without requiring new infrastructure and end-user devices.<ref name=Fitchard0>{{cite web|last=Fitchard|first=Kevin|title=Why Qualcomm thinks LTE-broadcast will work where FLO TV failed|url=http://gigaom.com/2013/04/09/why-qualcomm-thinks-lte-broadcast-will-work-where-flo-tv-failed/|accessdate=9 April 2013}}</ref>

The eMBMS service can offer many more TV programs in a specific radio frequency spectrum as compared to traditional terrestrial TV broadcasting, since it is based on the principles of [[Interactive Multicast]], where TV content only is transmitted in where there currently are viewers. The eMBMS service also provides better [[system spectral efficiency]] than [[video-on-demand]] over traditionall cellular unicasting services, since in eMBMS, each TV program is only transmitted once in each cell, alsoeven if there are several viewers of that program in the same cell. The MBSFN transmission mode further improves the spectral efficiency, since it is based on the principles of [[Dynamic single frequency networks]] (DSFN). This implies that it is dynamically forms [[single-frequency network]]s (SFNs), i.e. groups of adjacent base stations that send the same signal simultaneously on the same frequency sub-carriers, when there are mobile TV viewers of the same TV program content in the adjacent cells. The LTE [[OFDMA]] downlink modulation and multiple access scheme eliminates self-interference caused by the SFN:s. Efficient TV transmission using similar combinations of Interactive multicast (IP Multicast) and DSFN has also been suggested for the DVB-T2 and DVB-H systems.<ref>M. Eriksson, S.M. Hasibur Rahman, F. Fraille, M. Sjöström, ”[http://apachepersonal.miun.se/~mageri/myresearch/bmsb2013-Eriksson.pdf Efficient Interactive Multicast over DVB-T2 - Utilizing Dynamic SFNs and PARPS]”, 2013 IEEE International Conference on Computer and Information Technology (BMSB’13), London, UK, June 2013.</ref>

MBMS and [[mobile TV]] was a failure in 3G systems, and was offered by very few mobile operators, partly because of its limited peak bit rates and capacity, not allowing standard TV video quality, something that LTE with eMBMS does not suffer from.