Mobile communication method and mobile station to prohibit retransmission of assistance information

A mobile communication method comprising the steps of:

• transmitting mobile station assistance information to a radio base station by a mobile station, the mobile station assistance information prompting the radio base station to change a parameter for the mobile station used in the radio base station, wherein the mobile station assistance information includes a power saving preference for the mobile station;
• notifying, by the radio base station, the mobile station of a transmission-prohibited period of the mobile station assistance information;
• and
• stopping, by the mobile station, retransmission of the mobile station assistance information on the basis of the transmission-prohibited period, wherein the step of notifying the mobile station of a transmission-prohibited period comprises notifying the mobile station of a value indicating that the transmission-prohibited period is not permanently set.