WCDMA Channel Types

At the physical layer, the UE and the network communicate via a number
of physical channels. Many of these physical channels are used to carry
information that is passed to the physical layer from higher layers. Specifically,
information is passed to the physical layer from the MAC layer. The
interface between the physical layer and the MAC layer is comprised of a
number of transport channels, which are mapped to physical channels.
Moreover, information from the RLC layer to the MAC layer is passed in the
form of logical channels. These logical channels are mapped to transport
channels. The following sections consider these various channels in a little
more detail.We start with the transport channels.