esumption of data transfer as in e.g. LAPDm. 3.8.4 PDCP Services and Function The Packet Data Convergence Protocol (PDCP) service provides transmission and re- ception of network PDUs in acknowledged/unacknowledged and transparent RLC mode. As part of its function, first it maps network PDUs from one network protocol to one RLC entity. Second it compresses in the transmitting entity and decompresses in the receiving entity redundant network PDU control information (header compression/ decompression), including TCP/IP header compression and decompression when neces- sary. See more service and function details in [19]. 3.8.5 Broadcast/Multicast Control - Services and Functions The BMC provides broadcast/multicast transmission service in the user plane on the radio interface for common user data in transparent or unacknowledged mode. Its essen- tial functions include from [19]: Storage of cell broadcast messages stores messages received over the CBC- RNC interface for scheduled transmission. Traffic volume monitoring and radio resource request for CBS at the UTRAN side, it calculates the required transmission rate for cell broadcast service based on the messages received over the CBC-RNC interface, and requests appropriate CTCH/FACH resources from RRC. Scheduling of BMC messages The BMC receives scheduling information along with each cell broadcast message over the CBC-RNC-interface. Based on this UTRAN scheduling information, it generates schedule messages and schedules BMC message sequences correspondingly. At the UE side, it evaluates the sched- uled messages and indicates scheduling parameters to RRC, which are used by the RRC to configure lower layers for CBS discontinuous reception. The UMTS Development Platform Transmission of BMC messages to UE transmits BMC messages (scheduling and cell broadcast messages) based on a schedule. Delivery of cell broadcast messages to upper layer (NAS) delivers correctly re- ceived cell broadcast messages to upper layer (NAS) in the UE, neglecting cor- rupted ones. Specificati