antaneous transport format combination of the transport channels mapped to the uplink DPDCH transmitted simultaneously. There is one and only one uplink DPCCH on each radio link; however, there may be zero, one, or several uplink DPDCHs on each radio link. Figure 4.3 illustrates the frame structure of the uplink dedicated physical channels, where each frame has 10 ms length split into 15 slots (Tslot) of 2560 chips length, corresponding to one power control period. Parameter k in Figure 4.3 determines the number of bits per uplink DPDCH slot. It is related to the spreading factor defined as SF = 256/2k, which may range from 256 down to 4. The SF in the uplink DPCCH is always equal to 256 corresponding to 10 bits per uplink DPCCH slot. Table 4.4 illustrates the exact number of bits in the uplink DPDCH, while Table 4.5 shows the different uplink DPCCH fields (i.e. Npilot> NTFCI, NFBI, and NTPC). The pilot patterns are given Table 4.6 and the TPC bit pattern is given in Table 4.8. Upper layers configure the slot format. The channel symbol rate and SF for all cases in Table 4.5 are 15 and 256, respectively. Channel bit and symbol rates illustrated in Tables 4.4 and Table 4.5 reflect rates before spreading. Tslot - 2560 chips, Ndata = 10*2k bits (k=0..6) Data: Ndata bits DPDCH Tslot - 2560 chips, 10 bits DPCCH Pilot: Npilot bits TFCI: NTFCI bits FBI: NFBI bits TPC: NTPC bits Slot 0 Slot 1 Slot 5 Slot 14 1 radio frame: Tf = 10 ms Figure 4.3 Uplink frame structure DPDCH/DPCCH. The UTRA Physical Layer Design The FBI bits (S field and D field) support the techniques requiring feedback from the UE to the UTRAN access point, including closed loop mode transmit diversity and Site Selection Diversity Transmission' (SSDT). The open SSDT signalling uses the S field and the closed loop mode transmit diversity signalling uses the D field. The S field con- sists of 0, 1 or 2 bits while the D field consists of 0 or 1 bit. Table 4.5 shows the total FBI field size, i.e. the NFBI. Simultaneous use of SSDT power control and closed loop