If I am correct then your question is related to logical, transport and physical channels mapping.
Logical channels exist between RLC and MAC, transport channels exist between MAC and PHY and physical channels exist below PHY layer.
LTE supports various types of logical channels which used to carry types of information.
1. PCCH: Paging control channel is used to send paging messages.
2. BCCH: Broadcast control channel is used to carry system broadcast information. for example: SIBs
3. CCCH: Common control channel is used carry common signalling message like RRC connection request, RRC connection setup, RRC re-establishment request, RRC re-establishment etc message. All these messages are ue-associated but use CCCH channel since dedicated signalling bearer is not established till these messages exchange.
4. DCCH: Dedicated control channel, used to exchange UE-associated dedicated signalling messages. For example: RRC connection setup complete, RRC connection re-establishment complete, RRC connection reconfiguration, RRC connection re-configuration complete etc messages.
5. DTCH: Used to carry user-data (IP -packets)
6. MCCH: Used to signal multicast and broadcast control information.
7. MTCH: carries multicast broadcast data
All these logical channels mentioned above have mapping with transport channels
1. PCCH channel is mapped to PCH transport channel.
2. BCCH channel is mapped to BCH transport channel.
3. MTCH channel may be mapped to DL-SCH or MCH channel.
4. Rest of the logical channels mapped to DL-SCH and UL-SCH.
PCH, BCH, MCH, DL-SCH and UL-SCH all transport channels have following mapping with LTE physical channel.
1. PCH and DL-SCH both have mapping with PDSCH.
2. BCH channel has mapping with PBCH.
3. MCH channel has mapping with PMCH.
