ting the compressed mode section. 4.6.12.1 Uplink and Downlink Uplink. PhCHs used during a radio frame can go either full of bits transmitted over the air or not used at all. However, with UE in compressed mode the transmission gets turned off during consecutive slots of the radio frame. Downlink. PhCHs do not need to be transmitted full of bits over the air, e.g. bits Vpk E {0, 1} do not get transmitted. During compressed mode when reducing the SF by 2, no bits get mapped to the DPDCH field. See the logic of this event and more details in the DL physical channel mapping in [10]. The preceding sections complete the functional description of the multiplexing structure illustrated in Figure 4.49. Additional details on the presentation of each block can be found in [10] and [18]. 4.6.13 Detection of the Transport Format When the transport format set of a TrCH i contains more than one transport format, we can detected them according to one of the following schemes [10]: Transport Format Combination Indicator (TFCI) based detection: this scheme ap- plies when the transport format combination signals using the TFCI field; explicit blind detection: consists of detecting the TF of TrCH i by means of channel decoding and CRC check; guided detection: applies when there exists at least one other TrCH i', hereafter called guiding TrCH, such that: the guiding TrCH has the same TTI duration as the TrCH under consideration, i.e. Fi = F; different TFs of the TrCH under consideration correspond to different TFs of the guiding TrCH; we can use explicit blind detection on the guiding TrCH. If the transport format set for a TrCH i contains one transport format only, we do not need a transport format detection event for this TrCH. In the uplink, the blind transport format detection corresponds to network controlled option. In the downlink, the UE will perform blind transport format detection, when given conditions on the configured transport channels comply. For a DPCH associated with a PDSCH, the DPCCH in- cludes TFCI. The UMTS Netw