In 3GPP (Third Generation Partnership Project), which is a project aiming to standardize a mobile communication system, the specifications of Multimedia Broadcast Multicast Service (MBMS), as a technology for realizing multicast/broadcast transmission, have been laid down.
In the MBMS, a plurality of cells use a special subframe called a Multicast-Broadcast Single-Frequency Network (MBSFN) subframe, and a plurality of cells belonging to an identical MBSFN area transmit identical multicast/broadcast data. A user terminal receives the multicast/broadcast data transmitted from a plurality of cells.
In the MBMS, in addition to the MBSFN subframe being used for the MBMS, it is difficult to dynamically change the MBSFN subframe, and thus, a radio resource may not be effectively used.
On the other hand, in order to realize multicast transmission while increasing utilization efficiency of a radio resource, a Single-Cell Point-To-Multipoint (SCPTM) transmission has been discussed. Unlike the MBMS where multicast/broadcast transmission is applied per MBSFN area, in the SCPTM, the multicast transmission is applied per cell. Further, in the SCPTM, it is assumed that a physical downlink shared channel (PDSCH) is used for transmitting multicast data for a plurality of user terminals.
USPTO Backgrounds
USPTO Backgrounds