 that trans- mits UE-specific control information between a UE and the network and is used by the UEs that have established RRC connection with the network. Traffic channels are used for the transfer of user-plane information and are of the following type: Dedicated traffic channel (DTCH) is a UE-specific point-to-point channel for transport of user information which can exist in both uplink and downlink. The physical layer provides information transfer services to the MAC and higher layers. The physical layer transport services are described by how and with what characteristics data is transferred over the radio interface. This should be clearly distinguished from the classification of what is transported which relates to the concept of logical channels in the Control Traffic channels channels Control channels Traffic channels Uplink Downlink logical logical channels channels Uplink Downlink transport transport UL-SCH channels DL-SCH channels Figure 1.67 Mapping of logical and transport channels [16]. 138 Chapter 1 MAC sublayer. In the downlink, the logical channels and transport channels are mapped as follows (see Fig. 1.67): BCCH can be mapped to broadcast channel (BCH), which is characterized by fixed, predefined transport format, and is required to be broadcast in the entire coverage area of the cell. A DL-SCH may support receptions using different numerologies and/or TTI duration within the MAC entity. An UL-SCH may also support transmissions using dif- ferent numerologies and/or TTI duration within the MAC entity. BCCH can be mapped to downlink shared channel(s) (DL-SCH), which is characterized by support for HARQ protocol, dynamic link adaptation by varying modulation, coding, and transmit power, possibility for broadcast in the entire cell, possibility to use beam- forming, dynamic and semistatic resource allocation, and UE discontinuous reception (DRX) to enable power saving. PCCH can be mapped to paging channel (PCH), which is characterized by support for UE DRX in order to enable power saving, require