The present invention relates to an apparatus and a method for indicating a channel resource. The apparatus including a transmitter arranged to transmit an indicating acquisition indication channel signature wherein said indicating signature is used to indicate an enhanced dedicated channel resource (uplink resource set) to be used by a user equipment; a memory configured to store a mapping associating a random access channel signature sequence to one or more of the indicating acquisition indication channel signatures; and a data processor configured to use the stored mapping to relate a random access channel signature sequence to one or more of the indicating acquisition indication channel signatures; configured to relate each indicating acquisition indication channel signature to an uplink resource set such there is a three-way mapping between the random access channel signature sequence, the one or more indicating acquisition indication channel signatures and the uplink resource set.