Patent ID: 7720480
Filing Date: 2010-05-18
Classification: H04W

Abstract:
1. A radio communication method that uses a communication system which includes first and second communication connection apparatuses that communicate with a communication terminal by radio and a communication control apparatus that connects the first and the second communication connection apparatuses and a predetermined network and, in which communication data are transmitted from the first and second communication connection apparatuses in accordance with a DRC signal and a DSC signal, the communication method comprising: a first data transmission step in which the first communication connection apparatus receives the DRC signal and the DSC signal both of which include an identifier of the first communication connection apparatus from the communication terminal and transmits communication data from the communication control apparatus to the communication terminal in accordance with the DRC signal; a step in which the first communication connection apparatus, in a case of changing the DSC signal which is transmitted by the communication terminal, from the DSC signal including the identifier of the first communication connection apparatus to the DSC signal including an identifier of the second communication connection apparatus due to selection of the second communication connection apparatus by the communication terminal as a switching destination of a communication destination, transmits a sequence number of data following the communication data transmitted in the first data transmission step, received said DRC signal including the identifier of the first communication connection apparatus and received said DSC signal including the identifier of the second communication connection apparatus, to the communication control apparatus; a step in which the communication control apparatus transmits communication data to the second communication connection apparatus in accordance with the DSC signal, where the communication data has sequence numbers which include the sequence number received from the first communication connection apparatus and indicate the sequence number of data following the communication data transmitted in the first data transmission step and subsequent sequence numbers among the communication data which have been transmitted to the first communication connection apparatus; a step in which the communication control apparatus transmits communication data subsequent to data which have been transmitted to the first communication connection apparatus, to the first and second communication connection apparatuses; a second data transmission step in which the first communication connection apparatus transmits communication data from the communication control apparatus to the communication terminal in accordance with the DRC signal; an accumulating step in which the second communication connection apparatus accumulates the communication data of the sequence number and the subsequent sequence numbers from the communication control apparatus; a third data transmission step in which the second communication connection apparatus, in a case of changing the DRC signal which is transmitted by the communication terminal, from the DRC signal including the identifier of the first communication connection apparatus to the DRC signal including the identifier of the second communication connection apparatus, receives the DRC signal and the DSC signal including the identifier of the second communication connection apparatus from the communication terminal and transmits latest data or predetermined numbered data from the latest data among the communication data accumulated in the accumulating step to the communication terminal for inclucing a retransmission request message; a step in which the second communication connection apparatus receives, from the communication terminal, the retransmission request message for requesting lost data between the communication data received by the communication terminal in the first and the second data transmission step and the data received in the third data transmission step, the retransmission request message including a leading sequence number of the lost data; and a fourth data transmission step in which the second communication connection apparatus reads out communication data of the leading sequence number included in the received retransmission request message and subsequent sequence numbers among the communication data accumulated in the accumulating step and transmits the communication data to the communication terminal.