general very unreliable and dependent on cell overlap and network load at the time of measurement. One way to obtain such a mapping could be by simulation. A more reliable method would be to conduct measurements in an area that represents a 'typical' coverage area in the given network. An example of such measurement in an isolated cell at 2.6 GHz carrier frequency and 20 MHz bandwidth with no near-by interferers is shown in Figure 15.9. It is important to note that such a measurement from one network should not be reused in another network, since propagation environment, cell overlap, transmit powers, antenna types, network parameters and SO on all differ between networks. Hence if RSRP is to be used to predict throughput the measurement should be redone separately in every network and preferably repeated from time to time. In this regard, downlink or uplink throughput modelling based on RSRP resembles path loss model tuning; in both cases the model is only usable in the network and area type where it was measured. Vendor- and network-dependent uplink power control and link adaptation parameters can have a drastic impact on the uplink throughput curve. In Figure 15.9, average uplink through- put drops below 1 Mbps already at RSRP < -110 dBm. In the measurement, open-loop power control with full path loss compensation (alpha = 1) and received power target of P = -100 dBm per PRB was used. The downlink RS transmit power is 15 dBm per sub- carrier. It can be seen that the uplink throughput starts to drop at RSRP = -85 dBm which corresponds to UE-calculated path loss of 85+15 = 100 dB (which includes antenna gains). Plugging this path loss to the open-loop power control equation gives a UE transmit power of RSRP versus throughput, unloaded 20 MHz network 100,000 10,000 DL throughput UL throughput RSRP (dBm) Figure 15.9 Example measurement of RSRP versus Cat3 UE throughput in an isolated cell in low mobility; system bandwidth is 20 MHz Inter-layer Mobility Optimization -100 + 100 = 0 dBm per PRB. With 90 PRBs transmis