Transport and physical channels

Transport channels are based on physical channels, organized as shown in figure 25 . In addition to the physical channels that support transport channels, there are a few special physical channels that carry information specific to the physical layer and are transmitted by each base station:

• synchronization channel (SCH) ;

• common pilot channel (CPICH) ;

• acquisition indication channel (AICH) ;

• messaging indication channel (PICH) ;

• CPCH status indication channel (CSICH) ;

• collision detection channel and channel allocation indicator (CD/CA-ICH).