 the occurrences is very close to the level dictated by MCL and is about -49 dBm (= 21 dBm - 70 dB) [5]. The preceding event may show the same phenomenon with mixed speech and data systems, i.e. it would produce approximately the same result if the maximum power level for a data terminal were also 21 dBm. Figure 5.15 illustrates the CDF of the input signals to the receivers in mixed speech and data systems. This indicates that 99.99% of occurrences of the input signals to the re- ceivers are about -40 dBm or less. Because of the large cell, the MCL dictates the abso- lute maximum signal; and it is only a few dB higher, i.e. (33 dBm - 70 dB = -37 dBm). Probability of occurrence Amplitude of Total Received Signal at BS (dBm) Figure 5.15 CDF of total signal for mixed speech and data system with 5 km cells and worst case geographic offset (after [5]). The UTRA Transmission System Discussion in [5] indicates that it may be desirable to allow more than the 3 dB degrada- tion in sensitivity to that which is typically used in the measurement of a blocking specs. This can be justified because: the interfering UE's spurious and noise are going to dominate the noise in the vic- tim cell in a real system, and the measurement equipment is approaching the limit of its capability in the per- formance of this test. The first reason seems evident from observing that the interfering UE's noise two chan- nels from its assigned frequency is probably typically in the range of -90 dBm (= -40 dBm - 50 dB), which is much larger than the typical noise floor of the receiver at -103 dBm. The 2nd reason appears evident from observing that the typical noise floor of most high quality signal generators equals 65-70 dBc with a W-CDMA signal. The latter results in test equipment generated noise of -105 to -110 dBm, which can produce a significant error in the blocking measurement. In view of these concerns, it is probably reasonable to allow more than a 3 dB increase in the specified sensitivity level under the blocking conditions. In conclusio