Transmitting and receiving system, transmitting equipment, and transmitting method
In a case where it is determined that communication data indicates a first data attribute in a transmitter, that communication data is transmitted and an acknowledgement signal is requested to be sent back from a receiver. If the acknowledgement signal is not sent back, that communication data is retransmitted. In a case where it is determined that the communication data indicates a second data attribute in the transmitter, that communication data is transmitted and an acknowledgement signal is requested to be sent back according to an allowable number of retransmissions corresponding to the second data attribute. And that communication data is retransmitted in accordance with the allowable number of retransmissions and presence or absence of the acknowledgement signal sent back. The allowable number of retransmissions corresponding to the second data attribute is smaller than that corresponding to the first data attribute.
1 . A transmitting and receiving system for exchanging, between a transmitter and a receiver, communication data indicating either a first data attribute or a second data attribute having a lower priority in communications than the first data attribute,
wherein the transmitter includes:
a data input section for receiving the communication data,
a first analysis section for determining a data attribute of the communication data received by the data input section, and
a first transmitting section in which an allowable number of retransmissions for communication data indicating the second data attribute is limited, wherein if the first analysis section determines that the communication. data indicates the first data attribute, the first transmitting section transmits that communication data and requests that an acknowledgement signal be sent back, and if the first analysis section determines that the communication data indicates the second data attribute, the first transmitting section transmits that communication data and requests that the acknowledgement signal be sent back according to the allowable number of retransmissions; the receiver includes:
a receiving section for receiving the communication data from the transmitter,
a second analysis section for, when the receiving section receives the communication data, determining whether or not an acknowledgement signal for that communication data needs to be sent back, and
a second transmitting section for, if the second analysis section determines that the acknowledgement signal needs to be sent back, sending back the acknowledgement signal; where the first transmitting section transmits the communication data indicating the first data attribute, if the acknowledgement signal is not sent back, the first transmitting section retransmits that communication data, and where the first transmitting section transmits the communication data indicating the second data attribute, the first transmitting section retransmits that communication data in accordance with the allowable number of retransmissions and presence or absence of the acknowledgement signal sent back; and
the allowable number of retransmissions for the communication data indicating the second data attribute is smaller than that for the communication data indicating the first data attribute.
2 . The transmitting and receiving system of claim 1 , wherein when the first analysis section determines that the communication data indicates the first data attribute, the first transmitting section transmits that communication data and requests that the acknowledgement signal be sent back, and when the first analysis section determines that the communication data indicates the second data attribute, the first transmitting section transmits that communication data without requesting that the acknowledgement signal be sent back; and
where the first transmitting section transmits the communication data indicating the first data attribute, if the acknowledgement signal is not sent back, the first transmitting section retransmits that communication data, and where the first transmitting section transmits the communication data indicating the second data attribute, the first transmitting section does not retransmit that communication data.
3 . The transmitting and receiving system of claim 1 , wherein the first transmitting section transmits the communication data received by the data input section and requests that the acknowledgement signal be sent back; and
if the acknowledgement signal for the communication data is not sent back, the first transmitting section retransmits that communication data, but in a case in which that communication data indicates the first data attribute, if the number of times that communication data has been retransmitted exceeds M (where M is an integer equal to or greater than 2), the first transmitting section discontinues the retransmission of that communication data, and in a case in which that communication data indicates the second data attribute, if the number of times that communication data has been retransmitted exceeds N (where N is an integer equal to or greater than 1 but smaller than M), the first transmitting section discontinues the retransmission of that communication data.
4 . The transmitting and receiving system of claim 3 , wherein after the discontinuation of the retransmission of the communication data indicating the second data attribute, if communication data that is next to be transmitted indicates the second data attribute and that communication data relates to the communication data the retransmission of which was discontinued, the first transmitting section does not transmit that communication data indicating the second data attribute, and if the communication data that is next to be transmitted indicates the first data attribute, the first transmitting section transmits that communication data indicating the first data attribute.
5 . The transmitting and receiving system of claim 1 , wherein the transmitter further includes a measurement section for measuring a time period between the receipt of the communication data by the data input section and completion of transmission of that communication data by the first transmitting section; and
in a case in which the time period measured by the measuring section exceeds a predetermined time period, if communication data that is next to be transmitted indicates the second data attribute, the first transmitting section does not transmit that communication data indicating the second data attribute, and if the communication data that is next to be transmitted indicates the first data attribute, the first transmitting section transmits that communication data indicating the first data attribute.
6 . The transmitting and receiving system of claim 1 , wherein when the first transmitting section transmits the communication data indicating the first data attribute, the first transmitting section transmits that communication data at a first transmission rate, and when the first transmitting section transmits the communication data indicating the second data attribute, the first transmitting section transmits that communication data at a second transmission rate, which is faster than the first transmission rate.
7 . A transmitter for transmitting communication data indicating either a first data attribute or a second data attribute having a lower priority in communications than the first data attribute and for receiving an acknowledgement signal from a receiver, the transmitter comprising:
a data input section for receiving the communication data,
an analysis section for determining a data attribute of the communication data received by the data input section, and
a transmitting section in which an allowable number of retransmissions for communication data indicating the second data attribute is limited, wherein if the analysis section determines that the communication data indicates the first data attribute, the transmitting section transmits that communication data and requests that an acknowledgement signal be sent back, and if the analysis section determines that the communication data indicates the second data attribute, the transmitting section transmits that communication data and requests that the acknowledgement signal be sent back according to the allowable number of retransmissions,
wherein where the transmitting section transmits the communication data indicating the first data attribute, if the acknowledgement signal is not sent back, the transmitting section retransmits that communication data, and where the transmitting section transmits the communication data indicating the second data attribute, the transmitting section retransmits that communication data in accordance with the allowable number of retransmissions and presence or absence of the acknowledgement signal sent back; and
the allowable number of retransmissions for the communication data indicating the second data attribute is smaller than that for the communication data indicating the first data attribute.
8 . The transmitter of claim 7 , wherein when the analysis section determines that the communication data indicates the first data attribute, the transmitting section transmits that communication data and requests that the acknowledgement signal be sent back, and when the analysis section determines that the communication data indicates the second data attribute, the transmitting section transmits that communication data without requesting that the acknowledgement signal be sent back; and
where the transmitting section transmits the communication data indicating the first data attribute, if the acknowledgement signal is not sent back, the transmitting section retransmits that communication data, and where the transmitting section transmits the communication data indicating the second data attribute, the transmitting section does not retransmit that communication data.
9 . The transmitter of claim 7 , wherein the transmitting section transmits the communication data received by the data input section and requests that the acknowledgement signal be sent back; and
if the acknowledgement signal for the communication data is not sent back, the transmitting section retransmits that communication data, but in a case in which that communication data indicates the first data attribute, if the number of times that communication data has been retransmitted exceeds M (where M is an integer equal to or greater than 2), the transmitting section discontinues the retransmission of that communication data, and in a case in which that communication data indicates the second data attribute, if the number of times that communication data has been retransmitted exceeds N (where N is an integer equal to or greater than 1 but smaller than M), the transmitting section discontinues the retransmission of that communication data.
10 . The transmitter of claim 9 , wherein after the discontinuation of the retransmission of the communication data indicating the second data attribute, if communication data that is next to be transmitted indicates the second data attribute and that communication data relates to the communication data the retransmission of which was discontinued, the transmitting section does not transmit that communication data indicating the second data attribute, and if the communication data that is next to be transmitted indicates the first data attribute, the transmitting section transmits that communication data indicating the first data attribute.
11 . The transmitter of claim 7 , further comprising a measurement section for measuring a time period between the receipt of the communication data by the data input section and completion of transmission of that communication data by the transmitting section,
wherein in a case in which the time period measured by the measuring section exceeds a predetermined time period, if communication data that is next to be transmitted indicates the second data attribute, the transmitting section does not transmit that communication data indicating the second data attribute, and if the communication data that is next to be transmitted indicates the first data attribute, the transmitting section transmits that communication data indicating the first data attribute.
12 . The transmitter of claim 7 , wherein when the transmitting section transmits the communication data indicating the first data attribute, the transmitting section transmits that communication data at a first transmission rate, and when the transmitting section transmits the communication data indicating the second data attribute, the transmitting section transmits that communication data at a second transmission rate, which is faster than the first transmission rate.
13 . The transmitter of claim 7 , wherein the communication data indicating the first data attribute contains picture data that is referred to when other picture data is decoded; and
the communication data indicating the second data attribute contains picture data that is not referred to when other picture data is decoded.
14 . The transmitter of claim 7 , wherein the communication data indicating the first data attribute contains audio data; and
the communication data indicating the second data attribute contains video data.
15 . A transmitting method in which a transmitter receives communication data indicating either a first data attribute or a second data attribute having a lower priority in communications than the first data attribute and receives an acknowledgement signal from a receiver, the method comprising the steps of:
(a) determining a data attribute of the communication data received by the transmitter;
(b) if it is determined in the step (a) that the communication data indicates the first data attribute, transmitting that communication data and requesting that an acknowledgement signal be sent back, and if it is determined in the step (a) that the communication data indicates the second data attribute, transmitting that communication data and requesting that the acknowledgement signal be sent back according to an allowable number of retransmissions for the communication data indicating the second data attribute; and
(c) where the communication data indicating the first data attribute is transmitted in the step (b), if the acknowledgement signal is not sent back, retransmitting that communication data, and where the communication data indicating the second data attribute is transmitted in the step (b), retransmitting that communication data in accordance with the allowable number of retransmissions and presence or absence of the acknowledgement signal sent back,
wherein the allowable number of retransmissions for the communication data indicating the second data attribute is smaller than that for the communication data indicating the first data attribute.
16 . The transmitting method of claim 15 , wherein if it is determined in the step (a) that the communication data indicates the first data attribute, in the step (b) that communication data is transmitted and the acknowledgement signal is requested to be sent back, and if it is determined in the step (a) that the communication data indicates the second data attribute, in the step (b) that communication data is transmitted without requesting that the acknowledgement signal be sent back; and
if, in the step (b), the communication data indicating the first data attribute is transmitted but the acknowledgement signal is not sent back, that communication data is retransmitted in the step (c), and if, in the step (b), the communication data indicating the second data attribute is transmitted, that communication data is not retransmitted in the step (c).
17 . The transmitting method of claim 15 , wherein, in the step (b), the communication data received by the transmitter is transmitted and the acknowledgement signal is requested to be sent back; and
in the step (c), if the acknowledgement signal for the communication data transmitted in the step (b) is not sent back, that communication data is retransmitted, but in a case in which that communication data indicates the first data attribute, if the number of times that communication data has been retransmitted exceeds M (where M is an integer equal to or greater than 2), the retransmission of that communication data is discontinued, and in a case in which that communication data indicates the second data attribute, if the number of times that communication data has been retransmitted exceeds N (where N is an integer equal to or greater than 1 but smaller than M), the retransmission of that communication data is discontinued.
18 . The transmitting method claim 17 , further comprising the step of:
(d) after the discontinuation of the retransmission of the communication data indicating the second data attribute in the step (c), if communication data that is next to be transmitted indicates the second data attribute and that communication data relates to the communication data the retransmission of which was discontinued, canceling transmission of that communication data indicating the second data attribute, and if the communication data that is next to be transmitted indicates the first data attribute, transmitting that communication data indicating the first data attribute.
19 . The transmitting method of claim 15 , further comprising the steps of:
(d) measuring a time period between the receipt of the communication data by the transmitter and completion of transmission of that communication data by the transmitter; and
(e) in a case in which the time period measured in the step (d) exceeds a predetermined time period, if communication data that is next to be transmitted indicates the second data attribute, canceling transmission of that communication data indicating the second data attribute, and if the communication data that is next to be transmitted indicates the first data attribute, transmitting that communication data indicating the first data attribute.
20 . The transmitting method of claim 15 , wherein in the step (b), when the communication data indicating the first data attribute is transmitted, that communication data is transmitted at a first transmission rate, and when the communication data indicating the second data attribute is transmitted, that communication data is transmitted at a second transmission rate, which is faster than the first transmission rate.