Patent ID: 8477644

Claim:
A mobile station apparatus comprising: a radio unit configured to: transmit a Multimedia Broadcast Multicast Service (MBMS) service feedback request to a base station apparatus by performing contention based random access via Random Access Channel (RACH) in case that a condition for transmitting the MBMS service feedback request is satisfied, use a feedback resource, which is assigned by the base station apparatus based on the MBMS service feedback request, to transmit feedback information to the base station apparatus, and wherein the condition is a case where a Physical Downlink Control Channel (PDCCH) is allocated in a same subframe as a Physical Downlink Shared Channel (PDSCH) to be used for transmitting a MBMS service, the PDCCH cannot be decoded for a certain period of time, and a downlink channel condition or quality of the mobile station apparatus itself is equal to or less than a threshold broadcasted by the base station apparatus.