The present invention relates to receiving access signals from a plurality of terminals over a radio channel and in particular to determining a detection threshold level on the radio channel. A detection threshold level should balance the risk of missed detections to the risk of false detections. A problem in finding an equilibrium threshold is the radio environment, with noise and interference, change and then also the radio false detections or missed detections change. According to the present invention some access signals can be identified as being not assigned and therefore not being in use, and any detection of a non-used signal is identified as a false detection. By monitoring the ratio of false detections vs. correct detections the threshold level for detection is tuned into an equilibrium level, and that is adapted to the changing radio environments. In addition the detection threshold level for access signals detection threshold for data and/or control signalling may be adjusted in relation to the access signal threshold level.