TCTF MUX: this function represents the handling (insertion for uplink channels and detection and deletion for downlink channels) of the TCTF field in the MAC header, and the respective mapping between logical and transport channels.The TCTF field indicates the common logical channel type, or if a dedicated logical channel is used; add/read UE Id:
• the UE Id is added for CPCH and RACH transmissions
• the UE Id, when present, identifies data to this UE.
UL: TF selection: in the uplink, the possibility of transport format selection exists. In case of CPCH transmission, a TF is selected based on TF availability determined from status information on the CSICH;
ASC selection: For RACH, MAC indicates the ASC associated with the PDU to the physical layer. For CPCH, MAC may indicate the ASC associated with the PDU to the Physical Layer. This is to ensure that
RACH and CPCH messages associated with a given Access Service Class (ASC) are sent on the appropriate signature(s) and time slot(s). MAC also applies the appropriate back-off parameter(s) associated with the given ASC. When sending an RRC CONNECTION REQUEST message, RRC
will determine the ASC; in all other cases MAC selects the ASC;
scheduling /priority handling: this functionality is used to transmit the information received from MAC-d on RACH and CPCH based on logical channel priorities. This function is related to TF selection.
TFC selection: transport format and transport format combination selection according to the transport format combination set (or transport format combination subset) configured by RRC is performed,
