Method and apparatus for random access to radio services

A mobile station apparatus comprising:

• a receiver configured to receive control information;
• processing circuitry configured to randomly select a sequence from a plurality of sequences contained in one group of a plurality of groups into which a predetermined number of sequences that are generated from at least one base sequence are grouped, at least one of the groups being associated with a first respective range of data amounts and a respective range of reception qualities, wherein the predetermined number of sequences are grouped by partitioning the predetermined number of sequences, wherein sequences generated from a common base sequence are arranged in an increasing order of respective cyclic shifts associated with the sequences;
• wherein a position at which the predetermined number of sequences are partitioned is determined based on the control information, and a number of sequences contained in each of the plurality of groups varies in accordance with the control information;
• and
• a transmitter configured to transmit the selected sequence on a random access channel.