TFC
Transport Format Combination

The physical layer multiplexes one or several Transport Channels onto a Coded Composite Transport Channel. These Transport Channels each have defined transport formats (maybe from a Transport Format Set) which are applicable. However, at a given point of time, not all combinations of transport channels and their associated formats are permitted, hence a subset is defined. The Transport Format Combination is one of the subset, which identifies the transport channels with their chosen format that will make up the Coded Composite Transport Channel.