hat carries Layer 1 control information. The data and control parts are transmitted in parallel. The DPDCH field entries defined in Table 4.4 apply also to the data part of the CPCH message part. The control part of the CPCH message part has a spreading factor of 256, and it uses the same slot format as the control part of the CPCH PC-P. The pilot bit pat- terns defined in Tables 4.6 and 4.8 apply also to the pilot bit patterns of the CPCH mes- sage part. Figure 4.9 illustrates the uplink common packet physical channel frame structure. Each frame of length 10 ms is split into 15 slots having Tslot = 2560 chips length correspond- ing to one power-control period. Ndata bits Pilot Npilot bits NTFCI bits NFBI bits NTPC bits Control Tslot = 2560 chips, 10*2 k bits (k=0..6) Slot #0 Slot #i Slot # 14 1 radio frame: T f = 10 ms Figure 4.9 Frame structure for uplink data and control parts associated with PCPCH. The data part consists of 10 X 2k bits, where k = 0, 1, 2, 3, 4, 5, 6, corresponding to spreading factors of 256, 128, 64, 32, 16, 8, 4, respectively. 4.3.3.3 Spreading Common Uplink Physical Channels 4.3.3.3.1 PRACH The PRACH preamble part consists of a complex-valued code and the message part includes the data and control parts, Figure 4.10 illustrates its spreading principle. In the message part, real-value sequences represent the binary control and data parts i.e. the binary value '0' maps to the real value +1, while the binary value '1' maps to the real 1 N_Max_frames is a higher layer parameter. The UTRA Physical Layer Design value - -1. The channelization code Cc spreads the control part, while channelization code cd spreads the data part. After channelization, gain factor Bc for the control part and Bd for the data part weight the real-valued spread signals, where at least every instant in time one of the value BC and Bd have the amplitude 1.0. Table 4.9 illustrates quantization steps of the B-values quantized into 4 bit words. Once the weighting takes place, we treat the stream of real-valued chips on the 