- Inherited from the WCDMA, data on the transport channel is organized into “Transport Blocks”, TBs.
- A Transport block can be transmitted every TTI = 1 ms
The “Transport Format”, TF, defines how the blocks can be transmitted:
- Transport block size, it depends on the MCS and the number of PRB allocated
- Allowed modulation scheme
- Antenna mapping
- Broadcast Channel (BCH) characterized by a fixed, pre-defined transport format with a robust modulation to be broadcast in the entire coverage area of the cell.
- Downlink Shared Channel (DL-SCH) characterized by: A dynamic link adaptation by varying the modulation, coding and transmit power support for H-ARQ (radio retransmission).
- Paging Channel (PCH) characterized by: Requirement to be broadcast in the entire cell.
- Multicast Channel (MCH) characterized by: requirement to be broadcast in the entire coverage area of the cell
The following transport channels in UL have been defined by the 3GPP:
- Uplink Shared Channel (UL-SCH) characterized by: support for dynamic link adaptation by varying the transmit power and potentially modulation and coding , support for H-ARQ ,support for both dynamic and semi-static resource allocation.
- Random Access Channel (RACH) characterized by limited control information, collision risk