Multicast-broadcast single-frequency network

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Multimedia Broadcast multicast service Single Frequency Network (MBSFN) is a communication channel defined in the fourth-generation cellular networking standard called Long-Term Evolution (LTE). The transmission mode is intended as a further improvement of the efficiency of the enhanced Multimedia Broadcast Multicast Service (eMBMS) service, which can deliver services such as mobile TV using the LTE infrastructure, and is expected to compete with dedicated mobile/handheld TV broadcast systems such as DVB-H and DVB-SH. [1] [2] This enables network operators to offer mobile TV without the need for additional expensive licensed spectrum and without requiring new infrastructure and end-user devices. [3]

Contents

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 traditional cellular unicasting services, since in eMBMS, each TV program is only transmitted once in each cell, even 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 dynamically forms single-frequency networks (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. [4]

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.

Technical details

LTE's Enhanced Multimedia Broadcast Multicast Services (E-MBMS) provides transport features for sending the same content information to all the users in a cell (broadcast) or to a given set of users (subscribers) in a cell (multicast) using a subset of the available radio resources with the remaining available to support transmissions towards a particular user (so-called unicast services). It must not be confused with IP-level broadcast or multicast, which offer no sharing of resources on the radio access level. In E-MBMS it is possible to either use a single eNode-B or multiple eNode-Bs for transmission to multiple UEs. MBSFN is the definition for the latter. [5]

MBSFN is a transmission mode which exploits LTE's OFDM radio interface to send multicast or broadcast data as a multicell transmission over a synchronized single-frequency network (SFN). The transmissions from the multiple cells are sufficiently tightly synchronized for each to arrive at the UE within the OFDM Cyclic Prefix (CP) so as to avoid Inter-Symbol Interference (ISI). In effect, this makes the MBSFN transmission appear to a UE as a transmission from a single large cell, dramatically increasing the Signal-to-Interference Ratio (SIR) due to the absence of inter-cell interference. [6]

Commercial adoption

Commercial deployment of E-MBMS (and therefore MBSFN) features is expected to start in 2013 as an upgrade of existing LTE networks. [7] Lowell McAdam, CEO of Verizon, stated in his CES 2013 keynote that he hopes to have LTE-Broadcast available to live-broadcast the Super Bowl 2014 over its network. On a more general note, he identified live events as the ideal use case for LTE-Broadcast. [8]

Related Research Articles

<span class="mw-page-title-main">Multicast</span> Computer networking technique

In computer networking, multicast is a type of group communication where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one-to-many or many-to-many distribution. Multicast differs from physical layer point-to-multipoint communication.

<span class="mw-page-title-main">Orthogonal frequency-division multiplexing</span> Method of encoding digital data on multiple carrier frequencies

In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission used in digital modulation for encoding digital (binary) data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital communication, used in applications such as digital television and audio broadcasting, DSL internet access, wireless networks, power line networks, and 4G/5G mobile communications.

<span class="mw-page-title-main">Communication channel</span> Physical or logical connection used for transmission of information

A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for information transfer of, for example, a digital bit stream, from one or several senders to one or several receivers. A channel has a certain capacity for transmitting information, often measured by its bandwidth in Hz or its data rate in bits per second.

<span class="mw-page-title-main">Digital radio</span> Use of digital technology to transmit or receive across the radio spectrum

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<span class="mw-page-title-main">Single-frequency network</span>

A single-frequency network or SFN is a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel.

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<span class="mw-page-title-main">Orthogonal frequency-division multiple access</span> Multi-user version of OFDM digital modulation

Orthogonal frequency-division multiple access (OFDMA) is a multi-user version of the popular orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to individual users. This allows simultaneous low-data-rate transmission from several users.

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<span class="mw-page-title-main">E-UTRA</span> 3GPP interface

E-UTRA is the air interface of 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) upgrade path for mobile networks. It is an acronym for Evolved UMTS Terrestrial Radio Access, also known as the Evolved Universal Terrestrial Radio Access in early drafts of the 3GPP LTE specification. E-UTRAN is the combination of E-UTRA, user equipment (UE), and a Node B.

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Radio resource management (RRM) is the system level management of co-channel interference, radio resources, and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless local area networks, wireless sensor systems, and radio broadcasting networks. RRM involves strategies and algorithms for controlling parameters such as transmit power, user allocation, beamforming, data rates, handover criteria, modulation scheme, error coding scheme, etc. The objective is to utilize the limited radio-frequency spectrum resources and radio network infrastructure as efficiently as possible.

DVB-SH is a physical layer standard for delivering IP based media content and data to handheld terminals such as mobile phones or PDAs, based on a hybrid satellite/terrestrial downlink and for example a GPRS uplink. The DVB Project published the DVB-SH standard in February 2007.

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Broadcast and Multicast Service (BCMCS) is an interface for providing broadcast and multicast services in 3GPP2 CDMA2000 mobile networks. BCMCS can be used to transfer light video and audio clips or other data to a large group of mobile subscribers in an efficient manner. To do so, BCMCS is a so-called point-to-multipoint service. This means that multiple users receive the same information using the same radio resources.

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Integrated Mobile Broadcast (iMB) is a mobile wireless technology that enables broadcast of content at the cellular transmitter level, using the 3G or 4G licensed radio spectrum, and received on mobile terminals.

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References

  1. "Long Term Evolution (LTE): A Technical Overview" (PDF). Motorola Technical White Paper. p. 10.
  2. Turner, Lorraine. "3G evolution to rival DVB-H, WiMAX - Analysys". Total Telecom. Retrieved 9 February 2006.
  3. Fitchard, Kevin. "Why Qualcomm thinks LTE-broadcast will work where FLO TV failed" . Retrieved 9 April 2013.
  4. M. Eriksson, S.M. Hasibur Rahman, F. Fraille, M. Sjöström, ”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.
  5. Lescuyer, Pierre (2008). Evolved Packet System (EPS): The LTE and SAE Evolution of 3G UMTS. Wiley. pp. 140–143. ISBN   978-0-470-05976-0.
  6. Sesia, Stefania (2009). LTE - A Pocket Dictionary of Acronyms (PDF). Wiley. p. 45. ISBN   978-0-470-69716-0.
  7. Parker, Tammy. "Making the case for LTE Broadcast and Dyle mobile TV" . Retrieved 15 August 2012.
  8. Fitchard, Kevin. "Can LTE-broadcast dam the mobile video deluge?" . Retrieved 10 January 2013.