In this study a signal level of 1 volt/meter (2.6 mW/m2) will be used. This level should correspond to the level, experienced by the general public living rather near a base station antenna. The antenna arrangement will produce an approximation to a plane wave, so that the intensity is constant (within 2 dB) over the volume occupied by the subjects. The subjects are required to sit close to a computer screen and keyboard, which will modify the distribution slightly. The climatic chamber used for the study is modified with absorbing lining to dampen reflections from the walls. The chamber is also modified to make it a screened room to prevent external RF fields, and to some extent low frequency fields, to enter the chamber. Except for cables to the keyboard and screen there will be no other electromagnetic radiators in the chamber. The four different exposure types used, are Sham exposure (no radiation from the antennas), a UMTS signal (typical base station signal, 2140 MHz), a CW (continuous wave) of 2140 MHz. and a Wideband W-CDMA signal, f=2140 MHz, modulated with a random data sequence at a chip rate of 3.8 MHz, corresponding to a pure UMTS modulation signal, without the control signals.