 Taylor & Francis Group, LLC Measuring Performance of 3GPP LTE Terminals chamber during the calibration, as described in the calibration measurement section previously. The TRP measurement is performed in the following steps: Perform the calibration measurement procedure as described in the previ- ous section, including the calculations of mismatch and reference transfer function. 2. Measure the transmission loss of the cable connecting the power meter to the fixed-measurement antenna. Page the test unit and put it to radiate with maximum output power on the traffic channel of interest. Place the unit in the chamber. In the case of simulated-use testing, place the unit in the intended position relative to the tissue-simulating object (e.g., head or hand phantom). Use the power meter to sample the transmitted power in each position of the mode stirrers. 6. Calculate the TRP value by taking an average of all power samples and applying the calibration as described next. As in the radiation efficiency measurement, the TRP of the test unit is propor- tional to the average transferred power in the chamber. Through the calibration measurement, the average power transmission in the chamber is known, and there- fore the TRP can be calculated with the following equation: (12.22) where P(n) is the power samples in stirrer position n; N is the total number of stirrer positions; Tcable is the transmission in the cable connecting the power meter to the fixed- measurement antenna; and Gref and Rfix are as defined in the calibration section before. Note that the summation is done on decimal power values, even though the results are normally presented in decibels of measured power (dBm) units. 12.3.3 Measurement of Total Isotropic Sensitivity Total isotropic sensitivity is a common way of characterizing an active unit at downlink frequencies. The TIS measurement procedure is standardized by the CTIA organization [14] and an equivalent parameter with measurement procedure; © 2009 by Taylor & Francis Group, LLC Long Term Evolution: