The present invention discloses an apparatus, a method and a computer program for resolving a hidden node problem in relation to handshake message transferring e.g. in WLAN networks. In one embodiment of the invention, the apparatus receiving a Clear to Send (CTS) message repeats the message after a Short Interframe Space (SIFS) time period. Stations not directly hearing the original CTS due to a low power are able to receive the repeated CTS and defer their transmissions accordingly. In another embodiment, the apparatus receiving the CTS message indicates in its Ready to Send (RTS) message that the CTS sender station has a low transmitting power. With this knowledge, the other present stations can defer their transmissions until they are sure that the data transfer between the first two stations having the RTS-CTS messaging has not been initiated or is already completed.