• MAC header consist of:
• Target Channel Type field (TCFT): a flag that provides identification of the logical channel class on FACH and RACH transport channels.
(BCCH, CCCH, CTCH, SHCCH or dedicated logical channel information).
• C/T field: provides identification of the logical channel instance when multiple
logical channels are carried on the same transport channel.
• UE-Id field: provides an identifier of the UE on common transport channels.
– UTRAN Radio Network Temporary Identity (U-RNTI) may be used in the MAC header
of DCCH when mapped onto common transport channels in downlink direction; the URNTI
is never used in uplink direction;
– Cell Radio Network Temporary Identity (C-RNTI) is used on DTCH and DCCH in
uplink, and may be used on DCCH in downlink and is used on DTCH in downlink when
mapped onto common transport channels;
– the UE id to be used by MAC is configured through the MAC control SAP.
• UE-Id Type field: is needed to ensure correct decoding of the UE-Id field in MAC
Headers
