A method for maintaining synchronization of a user terminal (UE) in a radio communication system is proposed, wherein resources reserved for transmissions of random access signals are divided into at least one first portion for contention-based communication, and at least one second portion of said resources for contention-free communication, and wherein a user terminal (UE) is assigned at least one resource of the portion assigned to the contention-free communication, for transmitting signals for maintaining synchronization.