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values can range from 0 to 15. Either the data branch or the control branch musthave a signalled value of 15. In this example, the first transport format has a control branch gainoffset of 12/15 and a data branch gain offset of 15/15. This indicates that the data branch istransmitted with 1.9 dB more power than the control branch, i.e. power difference 10_ log(152/122). The second transport format has a control branch gain offset of 11/15 and a data branch gainoffset of 15/15. This indicates that the overhead generated by the control branch decreases as the bit

rate of the data branch increases. The log file also specifies the power offset to be applied between theacknowledged PRACH preamble and the control part of the PRACH message. This power offset canbe configured to have any integer value between_5 and 10dB. In this example, both transportformats have a power offset of 2 dB. Table 3.24 presents a set of example transmit powers for thegain offsets specified in Log File 3.9 assuming that the acknowledged PRACH preamble had atransmit power of 5 dBm. These figures illustrate that the transport format with the higher bit ratemakes use of a higher total transmit power although the transmit power allocated to the control

branch remains constant.RACHTFI 0TFI 1CCCH, DCCHDTCHRACHTFI 0TFI 1

CCCH, DCCHDTCHRACHTFI 0TFI 1Transport FormatCombination 2(CTCF = 1)