Abstract: A data communication system includes a server, data link started side apparatus, data link starting side apparatus, and originating server. The server provides a service through a network. The data link started side apparatus performs line control between itself and the line connection destination, and performs LAN control between itself and the server through the network, thereby relaying packets between the line connection destination and the server. The data link starting side apparatus is connected to the data link started side apparatus, disconnects the line between itself and the data link started side apparatus on the basis of an MITF dial-up dormant protocol when there is no communication between itself and the server for a predetermined period of time, and shifts to a dormant state.

Abstract: The present invention aims to provide a radio base station that has equivalently high reception sensitivity without increasing the number of antenna elements while keeping the utilization efficiency of time slots high. The radio base station comprises a radio unit 101 and a radio unit 102. Two time slots, one at each radio unit, are allocated to a mobile station. After a signal transmitted from the mobile station is received and demodulated, a piece of data received by the radio unit 101 is compared with a piece of data received by the radio unit 102 so that one of the pieces of data that has fewer errors is selected.