A new approach for efficient MBMS service provision in UTRAN

As currently specified by 3GPP, MBMS services can be provided in a cell either by point-to-point (PtP) or point-to-multipoint (PtM) transmission mode, but not both at the same time. With PtP transmission mode, one dedicated channel (DCH) is established for each MBMS user within the cell. With PtM transmission mode one forward access channel (FACH) is established, covering the whole cellpsilas area and commonly shared by all the MBMS users within. In this paper we describe the existing 3GPP MBMS service provision approach, highlight its deficiencies, and propose a new approach to address them. To achieve this we introduce the ldquodual transmission mode cellsrdquo in which PtP and PtM transmissions can coexist and where FACHpsilas coverage range can be dynamically adapted (shrink or expand) through time based on the MBMS userspsila location within the cell. The performance evaluation performed, showed that our approach outperforms the existing 3GPP approach in terms of capacity, signaling and processing effort efficiency.