Patent ID: 8054868

Claim:
A transmitting and receiving apparatus comprising: a request processing section configured to receive, from a terminal apparatus, a request to transmit requested data, and to transmit acknowledgement signal to the terminal apparatus when the request is received; a transmitting section configured to transmit the requested data to the terminal apparatus; a receiving section configured to receive propagation environment measurement signals from the terminal apparatus, each of the propagation environment measurement signals being received at a different timing; a time measurement section configured to measure a first time period between transmission of the acknowledgement signal and an initial reception of the propagation environment measurement signals from the terminal apparatus, and to calculate, based on the measured first time period, a second time period required for a signal transmitted from the transmitting and receiving apparatus to reach the terminal apparatus; a deciding section configured to compare signal intensity of each of the received propagation environment measurement signals and a predetermined threshold; and a control section configured to control the transmitting section to (i) continue transmitting the requested data while the propagating environment measurement signals are received from the terminal apparatus, (ii) intermit the transmission of the requested data when the propagation environment measurement signals are not received from the terminal apparatus, and (iii) when the deciding section makes a determination that the signal intensity of the propagation environment measurement signal is equal to or less than the predetermined threshold, measure a third time period between transmission of the requested data and the determination by the deciding section; compare the measured third time period to the second time period required for a signal transmitted from the transmitting and receiving apparatus to reach the terminal apparatus; and if a result of the comparison indicates that the requested data has not completely reached the terminal apparatus, retransmit the requested data to the terminal apparatus.