A method of requesting a random access connection between a mobile terminal and a base station, the method comprising, at the mobile terminal: receiving from a base station information comprising at least one signature root sequence index, a cyclic shift parameter, and a number of signatures used for representing a boundary between a first signature set and a second signature set; preparing random access signatures according to the at least one signature root sequence index and the cyclic shift parameter, wherein at least one of the random access signatures is associated with the first signature set and the rest of the random access signatures are associated with the second signature set, receiving from a base station an indication of at least one dedicated signature for use by the mobile terminal for contention-free mobile access and information indicating which transport format to be used in a random access procedure message for the transmission of data, selecting a dedicated signature based on the received indication from a set of signatures for contention-based random access for which reservation is allowed or from a set of signatures not used for contention-based random access; and transmitting the selected signature. receiving from a base station information comprising at least one signature root sequence index, a cyclic shift parameter, and a number of signatures used for representing a boundary between a first signature set and a second signature set; preparing random access signatures according to the at least one signature root sequence index and the cyclic shift parameter, wherein at least one of the random access signatures is associated with the first signature set and the rest of the random access signatures are associated with the second signature set, receiving from a base station an indication of at least one dedicated signature for use by the mobile terminal for contention-free mobile access and information indicating which transport format to be used in a random access procedure message for the transmission of data, selecting a dedicated signature based on the received indication from a set of signatures for contention-based random access for which reservation is allowed or from a set of signatures not used for contention-based random access; and transmitting the selected signature. receiving from a base station information comprising at least one signature root sequence index, a cyclic shift parameter, and a number of signatures used for representing a boundary between a first signature set and a second signature set; preparing random access signatures according to the at least one signature root sequence index and the cyclic shift parameter, wherein at least one of the random access signatures is associated with the first signature set and the rest of the random access signatures are associated with the second signature set, receiving from a base station an indication of at least one dedicated signature for use by the mobile terminal for contention-free mobile access and information indicating which transport format to be used in a random access procedure message for the transmission of data, selecting a dedicated signature based on the received indication from a set of signatures for contention-based random access for which reservation is allowed or from a set of signatures not used for contention-based random access; and transmitting the selected signature.