al Channels and the mapping between them can be referred to [3GP99b] and [3GP99c]. As mentioned in section 2.1, this thesis only considers UTRA-FDD mode. Figure 3.7 shows the corresponding Logical Channels, Transport Channels, and the mappings between them (refer to [3GP99b]). Uplink Downlink PCCH BCCH CCCH CTCH Logical channels Transport channels Figure 3.7: UMTS Rel99: Channel mapping in the uplink and downlink According to the nature of transferred information, the transport channels can be divided into two groups: common transport channels shared by more than one terminal, and dedicated transport channels used for connecting individual terminals with the network. Each group includes different channels in uplink and downlink directions. The Transport Channels in downlink direction are: Broadcast Channel (BCH) is a common channel used to transmit system information, e.g. code values used in the current and neighboring cells, allowed power levels, etc. Such data is broadcasted over the whole cell. Forward Access Channel (FACH) is a downlink low rate common channel used to transmit downlink signaling, e.g. for call setup and additionally small amounts of user data can be transmitted over this channel simultaneously. Paging Channel (PCH) is a common channel used by the network to reach a UE that is not currently maintaining an RRC connection with the radio access domain. The address 3 UMTS Terrestrial Radio Access Network (UTRAN) of the mobile terminal (UE) is paged once or several times. All terminals continuously listen to the PCH to pick up the paging request for them. Downlink Shared Channel (DSCH) is a common channel shared by several users, for whom the amount of information in downlink is small SO that there is no need for the allocation of a dedicated channel. However, this channel is not mandatory for the operation of the network and has not been widely used commercially. With the introduction of HSPA in Release 5 and 6, it becomes obsolete. Dedicated Channel (DCH) is the only dedicated transport channel.