ds on the spreading factor, as seen in Table 4.33. Both bursts have 96 chip long Guard Periods (GP). Table 4.33 TDD Burst Characteristics Symbols per Chip number Field length Field content data field (symbols) 0-975 0-1103 976-1487 1104-1359 1488-2463 1360-2463 2464-2559 2464-2559 The two different bursts illustrated in Figure 4.42 and characteristics noted in Table 4.33, can support a different set of applications and also allow optimization for particu- lar operational environments within the unlicensed frequency range. The UMTS Network and Radio Access Technology Data Symbols: Midamble: Data Symbols: GP: 96 976 Chips 512 Chips 976 Chips Chips 2560*Tc Data Symbols: Midamble: Data Symbols: GP: 96 1104 Chips 256 Chips 1104 Chips Chips 2560* Figure 4.42 TDD burst types. 4.4.3.1 Transmission of TFCI Both bursts (B1 and B2) afford uplink and downlink TFCI transmission. This transmis- sion is negotiated at call setup and re-negotiation may occur during a call. Upper layer signalling indicates TFCI formats for each CCTrCH with information on the presence or absence of TFCI. When a time slot contains a TFCI, transmission takes place using the first allocated channelization code in the time slot. The data parts of a corresponding physical channel realize the TFCI transmission fol- lowing the same spreading procedures outlined in [7], and while keeping the midamble structure illustrated in Figure 4.42. We transmit the TFCI information directly adjacent to the midamble, and after the TPC in the presence of power control commands. Figure 4.43 illustrates the two cases 1 superscript(1) st TFCI part 2nd TFCI part Data Symbols Midamble: Data Symbols GP 96 256/512 Chips Chips 2560* Data Symbols Midamble: Data Symbols GP 96 256/512 Chips Chips 2560*Tc Figure 4.43 TFCI information positions in traffic bursts. Both burst types 1 and 2 for dedicated channels provide the possibility for transmission of TPC in uplink. The transmission of TPC is negotiated at call setup and can be re-negotiated during the call. If applied, transmissi