Table 15.14 Idle mode mobility thresholds for LTE1800 and LTE2600 Idle mode parameter Value Comment qRxLevMin -120 dBm Both layers threshServingLow, P -112 dBm LTE1800/LTE800 exit point to UMTS900 in idle mode, broadcast on SIB3 threshX,low, P -110 dBm UMTS900 level entry point as RSCP, broadcast on SIB6. Value should guarantee network service with high probability. Should be set to a few decibels higher value than minimum RSCP threshold in UMTS900 (qRxLevMin) qHyst The same hysteresis in both directions. Low hysteresis to keep UE camping in the cell with the near-optimal path loss. Network optimized for low mobility Treselection 5 seconds For intra- and inter-frequency mobility. Long reselection timer to avoid ping-pong due to 2 dB hysteresis LTE Small Cell Optimization Table 15.15 Connected mode mobility thresholds for LTE1800 and LTE2600 Idle mode parameter Value Comment a3Threshold To trigger intra- and inter-frequency handover, same as idle mode hysteresis. Parameters optimized for low mobility a2Threshold -100 dBm Example value to trigger measurement gaps. Gaps should not be kept activated if inter-frequency handover is not triggered by A3 event after a guard time Time to trigger 2048 ms For A2 and A3 events, long timer to prevent ping-pong due to 2 dB offset Again, the problem is when to trigger the measurement gaps. From purely mobility point of view, the best solution would be to have gaps active all the time, but this reduces the number of resource blocks that can be allocated and also causes delay peaks that increase burstiness of TCP packet flows, risking further throughput degradation. A possible strategy would be to periodically activate gaps for short period when the serving cell level is higher than a threshold (defined by A1 event) in order to probe if a better inter-frequency cell can be found. If the serving cell level is lower than a threshold (defined by A2) the gaps could be active continuously. Smartphones tend to go to idle mode frequently, if inactivity timer is not too long, and this all