Kênh điều khiển chung (CCCH), để truyền thông tin điều khiển giữa mạng và UE theo cả hai hướng (thường được sử dụng bởi UE không có kết nối RRC với mạng và UE sử dụng các kênh vận tải thông thường khi truy cập vào một tế bào mới sau khi reselection tế bào). . | Introduction to WCDMA for UMTS 33 The meaning of the CCHs can be summarised as follows Broadcast Control Channel BCCH for broadcasting system control information in the downlink. Paging Control Channel PCCH for transferring paging information in the downlink used when the network does not know the cell location of the UE or when the UE is in cell-connected state . Common Control Channel CCCH for transmitting control information between the network and UEs in both directions commonly used by UEs having no RRC connection with the network and by UEs using common transport channels when accessing a new cell after cell reselection . Dedicated Control Channel DCCH a point-to-point bidirectional channel for transmitting dedicated control information between the network and a UE established through the RRC connection setup procedure . The TCHs can be described as Dedicated Traffic Channel DTCH a point-to-point channel dedicated to one UE for transfer of user information a DTCH can exist in both uplink and downlink directions . Common Traffic Channel CTCH a point-to-multi-point unidirectional channel for transfer of dedicated user information for all or a group of specified UEs. The mapping between logical and transport channels is depicted in Figure . Transport Channels Uplink Logical Channels FDD only Downlink BCCH Broadcast Control Channel DSCH Downlink Shared Channel BCH Broadcast Channel DTCH Dedicated Traffic Channel CCCH Common co o1 Channel FACH Forward Access Channel CCH Control Channel HS-DSCH High-speed DSCH CPCH Common Packet Channel PCCH Paging Control Channel CTCH Common Traffic Channel PCH Paging Channel DCCH Dedicated Control Channel RACH Random Access Channel DCH Dedicated Channel Figure Mapping between logical channels and transport channels in uplink and downlink directions for UTRA FDD only - . without TDD channels . 34 Radio Network Planning and Optimisation for UMTS Radio Link Control RLC Protocol The RLC protocol provides .
