Abstract: The present invention relates to an apparatus for transmitting and receiving signals in a wireless telecommunication system and to a method for transmitting random access bursts in such an apparatus. The apparatus 1 comprises transmitting means 3 for transmitting random access bursts, receiving means 4 for receiving acknowledgement information confirming a successful transmission of a random access burst, decision means for deciding if acknowledgement information has been received, and control means 6 for randomly choosing a time point for an attempt to retransmit said random access burst from an interval if no acknowledgement information has been received after a random access burst had been transmitted, whereby the control means sets the length of the interval depending on the number of unsuccessful attempts to transmit a random access burst. The proposed backoff scheme provides an improved performance and increased system stability without the need for a collision detection on the network side.