Multimedia Broadcast/Multicast Service (MBMS) is a feature to provide the capability for Broadcast and Multicast Services in GERAN (GSM/EDGE) or UMTS mobile networks. MBMS can be used to transfer light video and audio clips or other data to a large group of mobile subscribers in an efficiënt manner. To do so, MBMS is a so-called point-multipoint service. This means that multiple users receive the same information using the same radio resources.
In MBMS there are two different kinds of services defined. A broadcast service in which every user can receive the information within the service area and a multicast service in which only users that have subscribed to the service can receive the information. Multicast users have a return channel which gives the possibility for interactive services. This return channel can also be used to subscribe to the desired service.
Although MBMS can be used for mobile TV, it has some limitations in the capacity that can be used for this kind of services within the network. MBMS can take up to 30% of the capacity of a cell. In the first phase of Multimedia Broadcast and Multicast Service (MBMS) this cpacity can be used to deliver streams of 64 - 256 kbps over an UMTS network and 32 to 128 kbps streams over a GSM/EDGE network. Additional improvements in the technology (such as HSDPA) will enhance the throughput and the quality of service.