high system load. The results of these measurements are the individual throughputs of each terminal. They can be used not only to analyze sum-throughput in this artificial cell but also to investigate, for example, the fairness characteristics of the scheduling algorithm. 12.4.3 Multicell System-Level Measurements Rather than connecting only a single base station to a reverberation chamber, it is also possible to connect more than one base station. This setup can be used to inves- tigate the performance of the system when the terminal is moving in the handover area, as indicated in Figure 12.16. If two base stations with identical output powers are connected to a reverbera- tion chamber, the average received power from the two base stations at the terminal is also identical. The environment in the chamber therefore corresponds to exactly the handover region between two base stations. To change this, attenuators can be used to adjust the powers of the base stations connected to the chamber and, by that, "move" closer to one of the base stations. In the extreme, these attenuators might even be made time variant. Alternatively to using attenuators, it would also be possible to use a cylinder filled with lossy material and move it over the termi- nal in order to create fading on a slower timescale, which should trigger handover between two base stations. With such a setup, it is possible to simulate handover scenarios from one base to another. Such a handover decision should not be made on the basis of short-term fading but, rather, of average power levels. The short-term fading in this case would be created by the chamber. In addition to the base station/system algorithms, this setup will allow for evaluating the performance of the interference rejection at the terminal. If connected to one base station, the other base station creates interference © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology Table 12.2 Different Potential Measurement Setups Single Cell Multicell M