To actualize synchronization of frame timing between base stations for the mobile communication system which uses an IP(Internet protocol) network.
A transmission delay time calculating means 109 sends a message for transmission time measurement to each base station and statistically calculate the transmission time to the base station from its response time and a frame synchronism control means 107 sends a frame synchronism message including its transmission time information to each base station. Each base station having received the frame synchronism message generates frame timing by a frame timing generating means 108 by using the transmission time information to synchronize the frame timing among base stations connected by the IP network.
HAMADA TAKASHI
MARUYAMA TOMOAKI
