edicted SINR of a dual-carrier co-sited LTE800/ LTE2600 network for different network subcarrier activity factors; the subcarrier activity Yn is assumed the same for all cells in the measured cluster. Up to 16 strongest RSRPs have been measured with a scanner with >20 dB dynamic range and an external antenna on the car roof. From the result it can be seen that especially at 800 MHz the cell overlap is alarmingly high, since the extrapolated SINR would cross 0 dB for RSRP below -85 dBm even for an unloaded network (15% subcarrier activity). As the network RF load increases the SINR and hence throughput in the measured network would decrease further. In the example, the SINR degradation is equal to the increase in subcarrier activity since all cells are assumed to have the same activity factor, and thermal noise impact is negligible. The measured network average inter-site distance (ISD) is only about 600 metres and hence there are no RSRP samples below -80 dBm at 800 MHz when the level is measured outdoors with external scanner antenna. At 2.6 GHz, the impact of interference from intra-site sectors is seen as a dip in the curve at RSRP above -60 dBm, indicating measurement samples near the site and between sectors. For the purpose of designing mobility thresholds an RSRP-SINR curve similar to Figure 15.10 can be used for predicting SINR based on RSRP. As for a given network load, the SINR is determined by cell overlap; physical RF optimization is required to improve the fundamental RF performance of the network. Dependency of Throughput on System Bandwidth and SINR According to basic information theory, for a fixed SINR, throughput is linearly dependent on the system bandwidth. This should be taken into account in the planning of mobility thresholds, especially when using the A3 'power budget' event. Setting the A3 offset symmetrically for layers having different bandwidth may result in reduced throughput for the UE. The theoretical difference in SINR requirement for non-equal bandwidths could be obtained from the