Communication system,transmission device, reception device, and communication system having them
First Claim
1. A communication method of receiving, at a plurality of receiving stations, identical data packets transmitted from a transmitting station, each of the data packets including data divided into one or more data blocks each of which has an error correcting code, the communication method comprising the steps of:
- transmitting a retransmission request from (a) the receiving station that has received a data block with an uncorrectable error to (b) the transmitting station within a retransmission request permission period allocated for each receiving station, the transmission request being for the data block; and
retransmitting, from the transmitting station, the data block requested by the receiving station.
1 Assignment
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Accused Products
Abstract
Data packets [P(1) to P(8)] transmitted from a root station (1) is received at a plurality of leaf stations (A to C). The data packets [P(1) to P(8)] include a data block [B(101)], etc. each having an error correcting code. Besides, the data packets [P(1) to P(8)] includes information [L(201), L(202) to L(801), L(802)] on the right to make a retransmission request, for giving the right to make a retransmission request to the two of the leaf stations (A to C) in one communication cycle. The leaf stations (A to C) request the root station (1) to retransmit a data block for which error correction is impossible in a communication cycle when the leaf stations (A to C) are respectively given the right to make a retransmission request, by transmitting retransmission requesting packets [LA(1), LB(1), LC(1)], etc. The root station (1) transmits a data packet including the required data block in and after the next communication cycle. With this structure, data can be efficiently transmitted from a transmitting station to a receiving station without wasting a band, and data can be retransmitted so as to satisfy the requests from a plurality of receiving stations.
28 Citations
15 Claims
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1. A communication method of receiving, at a plurality of receiving stations, identical data packets transmitted from a transmitting station, each of the data packets including data divided into one or more data blocks each of which has an error correcting code, the communication method comprising the steps of:
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transmitting a retransmission request from (a) the receiving station that has received a data block with an uncorrectable error to (b) the transmitting station within a retransmission request permission period allocated for each receiving station, the transmission request being for the data block; and
retransmitting, from the transmitting station, the data block requested by the receiving station.
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2. A transmitting device for transmitting, to a plurality of receiving devices, identical data packets each of which includes data divided into one or more data blocks each having an error correcting code,
the transmitting device retransmitting a data block upon receipt of a retransmission request made, within a retransmission request permission period allocated for each receiving device, by the receiving device that has received the data block with an uncorrectable error, the retransmission request being for the data block.
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13. A receiving device for receiving a data packet including data divided into one or more data blocks each of which has an error correcting code, the data packet being transmitted from a transmitting device, the receiving device comprising:
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non-reception confirmation means for confirming, in case a data block is received with an uncorrectable error, that a retransmission request for the data block is transmitted to the transmitting device no less than a predetermined number of times, and the requested data block is not received from the transmitting device within a predetermined time period; and
retransmission request limiting means for limiting the retransmission request for the data block upon confirming by the non-reception confirmation means that the data block is not received. - View Dependent Claims (14, 15)
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Specification