Sunday, February 7, 2010

Logical Channels

  • Control Channels
Control channels are used for transfer of control plane information only. The control channels offered by MAC are:
    • Broadcast Control Channel (BCCH)
      A downlink channel for broadcasting system control information.
    • Paging Control Channel (PCCH)
      A downlink channel that transfers paging information and system information change notifications. This channel is used for paging when the network does not know the location cell of the UE.
    • Common Control Channel (CCCH)
      Channel for transmitting control information between UEs and network. This channel is used for UEs having no RRC connection with the network.
    • Multicast Control Channel (MCCH)
      A point-to-multipoint downlink channel used for transmitting MBMS control information from the network to the UE, for one or several MTCHs. This channel is only used by UEs that receive MBMS.
    • Dedicated Control Channel (DCCH)
      A point-to-point bi-directional channel that transmits dedicated control information between a UE and the network. Used by UEs having an RRC connection.
  • Traffic Channels

    Traffic channels are used for the transfer of user plane information only. The traffic channels offered by MAC are:
    • Dedicated Traffic Channel (DTCH)
      A Dedicated Traffic Channel (DTCH) is a point-to-point channel, dedicated to one UE, for the transfer of user information. A DTCH can exist in both uplink and downlink.
    • Multicast Traffic Channel (MTCH)
      A point-to-multipoint downlink channel for transmitting traffic data from the network to the UE. This channel is only used by UEs that receive MBMS.

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