Patent ID: 8400965

Claim:
A radio base station apparatus comprising: a radio control device; and a plurality of radio devices coupled to the radio control device via a plurality of links through which data are transmitted and received in frames, the radio control device serves as a master including a first reference counter that counts a clock pulse of the radio control device; a first holding unit that holds a count value of the first reference counter as a first transmission value when a first specific frame is transmitted from the master to a slave; a second holding unit that holds a count value of the first reference counter as a first reception value when a second specific frame transmitted from the slave is received by the master; and a first transmitting unit that transmits the first transmission value and the first reception value from the master to the slave, one of the plurality of radio devices serves as the slave including a second reference counter that counts a clock pulse of the slave; a third holding unit that holds a count value of the second reference counter as a second reception value when the first specific frame transmitted from the master is received by the slave; a fourth holding unit that holds a count value of the second reference counter as a second transmission value when the second specific frame is transmitted from the slave to the master; and a synchronization unit that calculates a difference between the count values of the first reference counter and the second reference counter from the first and second transmission values and the first and second reception values, and corrects the count value of the second reference counter based on the difference in order to match the count value of the second reference counter to the count value of the first reference counter, the synchronization unit calculates the difference from {( 1 d − 1 b )−( 1 h − 1 e )}/2, where 1 b denotes the first transmission value, 1 h denotes the first reception value, 1 e denotes the second transmission value, and 1 d denotes second reception value.