Data for a multicast service is provided by a radio communication system by performing header compression and employing a packet data convergence protocol (PDCP) entity that exists for every specific MBMS service to be provided for a cell with users therein. The particular network component (e.g., in a SRNC or a CRNC) that includes one PDCP layer for each specific MBMS service depends upon certain characteristics of the terminals (UE) located within a cell that wish to receive the specific MBMS service. The terminal receives via a common transport channel and restores (i.e., decompresses) the header-compressed data of the MBMS service that was transmitted after header compression at the CRNC, while the terminal receives via a dedicated transport channel and restores (i.e., decompresses) the header-compressed data of the MBMS service that was transmitted after header compression at the SRNC.