Multimedia Broadcast Multicast Service

Multimedia Broadcast Multicast Service (MBMS ) is a service in the UMTS mobile phone standard, capable of transmitting multimedia data such as mobile TV or files simultaneously and efficiently to many users. The advantage over the classical method in UMTS, in which a data stream is sent individually to each user, is the significantly lower network load, since the data is only once, at the same time to all transferred. This results in savings in both the radio network (Radio Access Network - RAN) as well as in the transport network where IP multicast can be used.

Technical Description

MBMS offers two transmission modes:

- Broadcast: whose UMTS MBMS receiver support coverage for all.

- Multicast reception of services that make authentication required.

For both modes, the radio network can determine the user density per cell and select the type of radio bearer (ie, point- to-point or point-to- multipoint support ). With few users point-to -point is ( conventionally or via HSDPA) efficient because optimization mechanisms such as power control can be used, while for many users, the point-to- multipoint transmission is cheaper, because the signal is sent only once and from a can be received unlimited number of users. The ability to select the carrier in broadcast mode, was late inserted into the Release 6 to enable the elimination of the multicast procedures can change faster between TV channels and at the same time to enable efficient transmission in the radio network. Both methods support encryption, so both free and fee-based services with two modes are possible.

MBMS is different from other methods that offer Mobile TV, such as DVB -H or DMB, the fact that the data is not transmitted via its own frequencies and transmitter similar to classic television, but via UMTS. This has the advantage that it must purchase additional frequencies and not build new network infrastructure for mobile operators. In addition, the services in geographically limited areas can be offered ( cell-based ), such as special channels in football stadiums. MBMS is not limited to video transmission, but also offers the possibility (eg podcasts) to distribute files to many users.

A disadvantage of the use of MBMS for mobile TV is the relatively low number of simultaneously transmitted television channels ( four to eight point-to- multipoint transmissions per 5 MHz carrier ), wherein a large portion of the cell capacity for MBMS services used. However, only the channels in a cell must be sent, which can also be used.

MBMS is part of the UMTS specification from Release 6, which is largely completed in the standardization body 3GPP.

EMBMS

Evolved Multimedia Broadcast Multicast Service ( eMBMS ) is the extension in the context of 3GPP Long Term Evolution ( LTE) and System Architecture Evolution (SAE ). eMBMS for LTE has been standardized by 3GPP Release 9 and expanded with 3GPP Release 11 for service continuity for eMBMS. With eMBMS 20 TV channels with 256 kbps data rate in a 5 MHz LTE band can be transferred.

Use

So far (as of October 2013) are no mobile operator known, use the MBMS commercially. The U.S. mobile operator Verizon has announced plans to broadcast the Super Bowl in 2014 by eMBMS over its LTE network.

References

• Mobile technology