The invention relates to a mechanism for decreasing power consumption in a wireless terminal intended for a communication system where availability of a common air medium is to be determined by the terminal prior to transmission. The terminal selects at least one communication device as a communicating peer and adjusts receiver performance based on received signal strength and optionally other parameters measured from at least one of the at least one wireless communication device, the receiver performance being adjusted for listening to the at least one wireless communication device with reduced power consumption. The terminal further generates an indication when its own transmission is approaching and readjusts the receiver performance for determining the availability of the common air medium at a performance level enabling detection of devices that may be disturbed by said own transmission.