 3GPP LTE Radio and Cellular Technology however, under the name "total radiated sensitivity" (TRS), is standardized by the 3GPP organization. TIS can be measured in a reverberation chamber by the pro- cedure described here. Instrumentation and setup are similar to the TRP measure- ment case described earlier and shown in Figure 12.7b. Simplified, the TIS parameter is equal to the conducted sensitivity of the test unit's receiver degraded by the radiation efficiency of the antenna to which it is connected. In reality, the TIS parameter will also be affected by any interference guided to the receiver by the mechanical structure (including the antenna) of the test unit. TIS is measured under static signal conditions (i.e., mode stirrers are kept still at each sample point) and the idea is to measure sensitivity due to noise impairment only. Due to the multiple reflections in the reverberation chamber, a delay spread of the incoming signals to the receiver will occur; this can be an added effect to the BER. In cases where the impairment due to signal replicas is unwanted, the actual effect of the delay spread in the present case can be tested prior to the TIS measurement. The test consists of putting the test unit in the chamber, setting up a loopback connection with the base station simulator, and then starting a BER measurement while the output powers of the test unit and base station simulator are both high enough to avoid bit errors due to low SNR. If the BER is zero in this setup, the effect of delay spread is negligible. The TIS procedure is based on searching for the lowest base station simulator output power in each position of the mode stirrers that gives a BER better than the specified target BER level. The procedure can be done in the following steps: 1. Perform the calibration measurement procedure as described in the cali- bration measurement section, including the calculations of mismatch and reference transfer function. 2. Measure the transmission loss of the cable connecting the base station sim- ulat