The present invention relates to a method for detecting a number of user terminals (8a, 8b), each of said user terminals (8a, 8b) comprising a receiver unit (10), a transmitter unit (11) and a control unit (12) arranged to control said receiver unit (10) and transmitter unit (11), each of said user terminals (8a, 8b) also being associated with a wireless communication network (1) comprising a plurality of network cells (2, 3), each being equipped with a node (4, 5). The method comprises detecting (16) communication between each of said user terminals (8a, 8b) and an associated node (4; 5) of said wireless communication network (1). Furthermore, the method comprises: detecting (17) a first control message being transmitted from a user terminal (8a, 8b); detecting (18) a second control message being transmitted from a node (4; 5), said second control message being associated with the first control message; and increasing (19) a counter (15a) representing said number of user terminals (8a, 8b) based on detection of transmission of said control messages. The present invention also relates to a detector device (9) for detecting a number of user terminals (8a, 8b).