Method and apparatus for using radio channels

An apparatus, comprising:

• at least one processor;
• and
• at least one memory including computer program code,
• the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:
• detect either a first radio channel to be free of primary users or an interference limitation of the first radio channel for a secondary user apparatus, a primary user apparatus having priority over the secondary user apparatus for the first radio channel;
• if the first radio channel is detected to be free of primary users, select, by the apparatus, the first radio channel for communication with another apparatus to both a first direction and a second direction, opposite to the first direction;
• if the interference limitation of the first radio channel is detected, select the first radio channel for communication between the secondary user apparatus and the another apparatus to the first direction after detecting the interference limitation, and select a second radio channel for communication with the another apparatus to the second direction.