ion requests. During the mass events it is recommended to use very conservative power control settings in order to reduce the inter-cell interference and protect the random access success rate and RRC setup success rate KPIs and uplink throughput performance. Conservative power control settings mean that the open-loop part of the uplink power control should be set to have PO_NOMINAL PUCCH as around -105 dBm and alpha as 1. PUSCH closed-loop power control settings should be set to have large SINR window of 0-20 dB and fairly narrow RSSI window of -108 to -98 dBm. When this type of uplink power control strategy for PUSCH is used the performance is greatly improved as can be seen when the graphs for the same cells with aggressive power control shown in Figures 13.8 and 13.20 are compared to conservative power control shown in Figures 13.24 and 13.25, respectively. It can be seen that with conservative Peak RRC connection requests per second Peak to average Figure 13.23 Peak RRC connection requests per second and peak to average ratio of received RRC connection requests LTE Small Cell Optimization Average PUSCH RSSI Average PUSCH SINR Average number of preambles Average UL data volume Figure 13.24 Uplink data volume, SINR, RSSI and number of received preambles averaged over highest loaded cells for conservative uplink power control strategy; 15-minute data samples are used uplink (PUSCH and PUCCH) power control the collapse of PUSCH SINR, random access and RRC connection setup success rate can be avoided as well as the increase of PUSCH RSSI when uplink data volume or signalling increases. In case the maximum supported RRC-connected users capacity is too low it can cause massive amount of RRC connection setup rejections and increased interference due to the re-attempts. This topic is discussed more detailed in Section 13.5.2. Average PUSCH RSSI Random access setup success rate Average PUSCH SINR RRC connection setup success rate Figure 13.25 Average received signal strength indicator (RSSI), signal to interference an