C) testing of radiated emissions and immunity. It is basically a metal cavity that is sufficiently large to support many resonant modes, and it is provided with means to stir the modes SO that a statistical field variation appears. It has been shown that the reverberation chamber represents a multipath environment similar to what we find in urban and indoor environments. Therefore, during recent years it has been developed as an accurate instrument for measuring desired radiation properties for small antennas as well as active mobile terminals designed for use in environments with multipath propagation. Chapter 12 ("Measuring Performance of 3GPP LTE Terminals and Small Base Stations in Reverberation Chambers") uses a hands-on approach, starting by reviewing basic properties of reverberation chambers and giving an overview of ongoing research and benchmarking activities. It then describes how to calibrate reverberation chambers and how they are used to measure antenna efficiency, total radiated power (TRP), and total isotropic sensitivity (TIS)-important parameters for all wireless devices with small antennas, including 3GPP LTE terminals and small base stations. It also describes how diversity gain and MIMO capacity can be © 2009 by Taylor & Francis Group, LLC Introduction measured directly in the Rayleigh environment (in about 1 minute, compared to hours or more using other technologies), using a multiport network analyzer. The first-ever repeatable system throughput measurements in a reverberation chamber are described. In order to evaluate the performance of multiantenna wireless communication systems, classical measurement techniques known from antenna measurements, such as anechoic chambers, are no longer sufficient. The measurement setups for (multi-) antenna measurements presented in the first part of this chapter show how reverberation chambers can be used as an alternative to current techniques. The accuracy of the reverberation chamber measurements has been analyzed and com- pared to classic antenna mea