on gets interrupted if the number of bits is lower than maximum. When the number of bits between different uplink TTIs changes, bits get repeated or punc- tured to ensure that the total bit rate after TrCH multiplexing is identical to the total channel bit rate of the allocated dedicated physical channels. If the rate matching event does not get input bits for all TrCHs within a CCTrCH, the rate matching does not out- The UMTS Network and Radio Access Technology put bits for all TrCHs within the CCTrCH and no uplink DPDCH will mean no selec- tion of uplink rate matching. See the detailed description of rate matching characteris- tics, such as determination of rate matching in uplink/downlink, as well as separation and collection in uplink/downlink in [10]. 4.6.8 TrCH Multiplexing The TrCH delivers one radio frame every 10 ms to the TrCH multiplexing, which are serially multiplexed into a Coded Composite Transport Channel (CCTrCH). We denote by the input bits going to the TrCH multiplexing, where i is the TrCH number and V is the number of bits in the radio frame of TrCH i. Likewise, we denote by I the number of TrCHs, and by S1,S23S33....SS the output bits from TrCH multiplexing, where S is the number of bits, i.e. [10]. (4.78) The TrCH multiplexing is defined by the following relations: (4.79) k=V,+1,V++2...,V,+V2 (4.80) (4.81) (4.82) (4.83) 4.6.9 Discontinuous Transmission (DTX) Bits Insertion We use DL DTX to fill up the radio frame with bits, where the insertion point of these bits can have either fixed or flexible positions of the TrCHs in the radio frame. It de- pends on the UTRAN to decide for each CCTrCH whether it will have fixed or flexible positions during the connection. DTX indication bits communicate only when the transmission will get turned off, i.e. they are not transmitted themselves. 4.6.9.1 First Insertion of DTX Indication Bits First DTX indication bits insertion occurs only if the positions of the TrCHs in the radio frame are fixed. In the fixed position scheme, we reserve a fixed number of 