Patent ID: 8571567

Claim:
A radio terminal apparatus using a random access channel (RACH), the apparatus comprising: a receiving section that receives a pilot signal transmitted from a base station apparatus; a measuring section that measures a reception power of the pilot signal; a selecting section that selects, based on the reception power measured by the measuring section, one code group among a plurality of code groups into which codes for contention based initial access before a connection to the base station apparatus is established are divided, the code groups being respectively associated with different ranges of reception powers at the radio terminal apparatus; and a transmitting section that performs a transmission to the base station apparatus for the contention based initial access via the RACH using a code randomly selected from codes of the selected one code group, whereby the selected one code group to which said code belongs provides an indication to the base station apparatus of radio condition at the radio terminal apparatus, wherein a range of a lower reception power is narrower than a range of a higher reception power such that a larger number of codes are included in a code group associated with a lower reception power than a code group associated with a higher reception power, and no code group is associated with a reception power that is less than a given value.