EP1006689A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Packet retransmission control using priority information
Assignee: Panasonic Corp
•
Filing: 1999-11-30
•
Granted: —
•
Expires: 2019-11-30
Abstract
Abstract A data transmission apparatus for relaying data transmitted from the transmitting end in units of packets, each packet having additional information relating to its sequence number, priority, and data reproduction time, comprises: a receiving unit for receiving packets transmitted from the transmitting end; a priority decision unit for deciding the priority of each of the received packets; a retransmission packet storage unit for storing packets the priorities of which are equal to or higher than a predetermined value, as retransmission packets, on the basis of the priority of each packet decided by the priority decision unit; a retransmission instruction receiving unit for receiving a retransmission request from a terminal at the receiving end; a retransmission decision unit for deciding whether retransmission of the packet for which the retransmission request has been made should be performed or not, on the basis of the retransmission request and the storage status of the retransmission packets in the retransmission packet storage unit; a transmission queue management unit for setting the transmission order of the received packets and the packets which have been decided as packets to be retransmitted, on the basis of additional information which is given to each packet; and a transmission unit for transmitting the data of these packets in the transmission order set by the management unit. Therefore, the transmission quality in a radio section in real-time transmission is improved and, further, the number of retransmission times is reduced.
Inventors
- 👤 Hideaki Fukushima
- 👤 Seiji Horii
- 👤 Tatsuya Ohnishi
- 👤 Makoto Hagai
- 👤 Yoshinori Matsui
- 👤 Akihiro Miyazaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 07:17
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/12; H04L1/16; H04L1/18; H04L1/1809; H04L1/0078; H04L1/0079; H04L1/008; H04L1/1607; H04L1/1642; H04L1/1829; H04L1/1835; H04L1/1838; H04L1/1854; H04L1/1867; H04L1/1874; H04L1/1877; H04L1/1887
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
218 words
A data transmission method for performing continuous data
transmission from the transmitting end to the receiving end in
units of packets, each packet having additional information
relating to its sequence number, priority, and data reproduction
time at the receiving end, while successively reproducing data of
packets received at the receiving end, said method comprising the
steps of: at the transmitting end, giving priority information to each packet to be transmitted;
and storing, as retransmission data, only data of packets the
priorities of which are equal to or higher than a predetermined
value, in a retransmission buffer; at the receiving end, when a transmission error is detected, detecting the priority
information of an error packet; and when the detected priority is equal to or higher than the
predetermined value, outputting a retransmission request for the
error packet to the transmitting end by indicating the sequence
number of this error packet; at the transmitting end, only when the data of the packet having the sequence number
which is indicated by the retransmission request from the
receiving end is stored in the retransmission buffer,
retransmitting the data of this packet to the receiving end; and discarding the data stored in the retransmission buffer in
order starting from a packet which cannot be in time for data
reproduction at the receiving end.
Claim 2
Dependent Claim
66 words
The data transmission method of Claim 1 wherein, when the
retransmission buffer is filled up to its capacity, an updation
process is performed, in which the retransmission data are
retained while the data stored in the retransmission buffer are
discarded in order, starting from a packet of the earliest
reproduction time, on the basis of the reproduction time of each
packet stored in the retransmission buffer.
Claim 3
Dependent Claim
48 words
The data transmission method of Claim 1 wherein, when the
data transmitted from the transmitting end to the receiving end
is video data based on MPEG, a packet which contains data
corresponding to frames coded by utilizing intra-frame
correlation is regarded as a packet having a high priority.
Claim 4
Dependent Claim
112 words
The data transmission method of Claim 1 wherein: at the transmitting end, the additional information relating
to the sequence number and the priority of a predetermined packet
is also embedded in a subsequent packet to be transmitted after
the predetermined packet; and at the receiving end, in the case where a transmission error
has occurred in the predetermined packet and the additional
intonation of the predetermined packet has an error, a
retransmission request for the predetermined packet as an error
packet is made on the basis of the additional information of the
predetermined packet which is embedded in the subsequent packet,
when the subsequent packet transmitted after the predetermined
packet is received.
Claim 5
Dependent Claim
105 words
The data transmission method of Claim 4 wherein: at the transmitting end, the process of embedding the
sequence number of a predetermined high priority packet in a
subsequent packet which follows the predetermined high priority
packet is continuously performed until a high priority packet
next to the predetermined high priority packet is transmitted;
and at the receiving end, the sequence number of another packet
which is embedded in the received packet is extracted, and when a
transmission error has occurred in the packet of the extracted
sequence number, a retransmission request for this error packet
is made by indicating the sequence number of this packet.
Claim 6
Dependent Claim
221 words
A data transmission apparatus for relaying data which are
successively transmitted from the transmitting end in units of
packets, each packet having additional information relating to
its sequence number, priority, and data reproduction time at the
receiving end, said apparatus comprising: a receiving unit for receiving the packets transmitted from
the transmitting end; a priority decision unit for deciding the priority of each of
the received packets; a retransmission packet storage unit for storing packets the
priorities of which are equal to or higher than a predetermined
value, as retransmission packets, on the basis of the priority of
each packet decided by the priority decision unit; a retransmission instruction receiving unit for receiving a
retransmission request from a terminal at the receiving end; a retransmission decision unit for deciding whether
retransmission of the packet for which the retransmission request
has been made should be performed or not, on the basis of the
retransmission request and the storage status of the
retransmission packets in the retransmission packet storage unit; a transmission queue management unit for setting the
transmission order of the received packets and the packets which
have been decided as packets to be retransmitted, on the basis of
the additional information; and a transmission unit for transmitting the data of these
packets in the transmission order set by the management unit.
Claim 7
Dependent Claim
175 words
A data receiving apparatus for receiving data which are
transmitted from the transmitting end in units of packets, each
packet having additional information relating to its sequence
number, priority, and data reproduction time at the receiving end,
and successively reproducing the data for each packet, said
apparatus comprising: a receiving unit for receiving the packets transmitted from
the transmitting end; an error packet detection unit for detecting error packets in
which errors have occurred during transmission, and outputting
normal packets which have been transmitted without transmission
errors, on the basis of the data of the received packets; a packet priority decision unit for receiving the output from
the error packet detection unit, and deciding error packets the
priorities of which are equal to or higher than a predetermined
value; and a retransmission instruction output unit for outputting a
retransmission request for each of the error packets the
priorities of which are decided as being equal to or higher than
the predetermined value, to the transmitting end, by indicating
the sequence number of this error packet.
Claim 8
Dependent Claim
289 words
A data transmission method in which data transmission from
the transmitting end to the receiving end is continuously
performed in units of packets, each packet having additional
information relating to its sequence number, priority, and data
reproduction time at the receiving end, while successively
reproducing data of packets which have arrived at the receiving
end and, at this time, only packets which can be in time for data
reproduction at the receiving end are retransmitted, said method
comprising the steps of: at the transmitting end, giving a data reproduction time at the receiving end to
each packet to be transmitted; and storing, as retransmission data, only data of packets the
priorities of which are equal to or higher than a predetermined
value, in a retransmission buffer; at the receiving end, when a transmission error is detected, detecting the
reproduction time for an error packet and the arrival time of the
error packet, and deciding an arrival time limit in accordance
with the reproduction time; and when the error packet has arrived before the arrival time
limit, outputting a retransmission request for the error packet
to the transmitting end by indicating the sequence number of this
error packet; at the transmitting end, when the data of the packet having the sequence number
indicated by the retransmission request from the receiving end is
stored in the retransmission buffer, retransmitting data of the
packet the transmission time of which does not pass the
reproduction time, to the receiving end, while discarding data of
the packet the transmission time of which has passed the
reproduction time; and discarding the data stored in the retransmission buffer
in order starting from a packet which cannot be in time for data
reproduction at the receiving end.
Claim 9
Dependent Claim
66 words
The data transmission method of Claim 8 wherein, when the
retransmission buffer is filled up to its capacity, an updation
process is performed, in which the retransmission data are
retained while the data stored in the retransmission buffer are
discarded in order, starting from a packet of the earliest
reproduction time, on the basis of the reproduction time of each
packet stored in the retransmission butter.
Claim 10
Dependent Claim
44 words
The data transmission method of Claim 8 wherein the arrival
time limit is decided based on at least one of the allowable
packet delay time decided at the receiving end, and the packet
transmission delay time between the transmitting end and the
receiving end.
Claim 11
Dependent Claim
112 words
The data transmission method of Claim 8 wherein: at the transmitting end, additional information relating to
the sequence number and the reproduction time corresponding to a
target packet to be transmitted is embedded in a subsequent
packet to be transmitted after the target packet; and at the receiving end, when a transmission error of the
target packet has occurred and the additional information of the
target packet has an error, a retransmission request for the
target packet as an error packet is made on the basis of the
additional information of the target packet which is embedded in
the subsequent packet, when the subsequent packet transmitted
after the target packet is received.
Claim 12
Dependent Claim
274 words
A data transmission apparatus for relaying data which are
successively transmitted from the transmitting end in units of
packets, each packet having additional information relating to
its sequence number, priority, data reproduction time at the
receiving end, said apparatus comprising: a receiving unit for receiving the packets transmitted from
the transmitting end; a priority decision unit for deciding the priority of each of
the received packets; a reproduction time decision unit for deciding packets which
cannot be in time for reproduction at the receiving end, amongst
the packets to be transmitted to the receiving end; a retransmission packet storage unit for storing packets the
priorities of which are equal to or higher than a predetermined
value, as retransmission packets, on the basis of the priority of
each packet decided by the priority decision unit; a retransmission instruction receiving unit for receiving a
retransmission request from a terminal at the receiving end; a retransmission decision unit for deciding whether
retransmission of the packet for which the retransmission request
has been made should be performed or not, on the basis of the
retransmission request and the storage status of the
retransmission packets in the retransmission packet storage unit; a transmission queue management unit for setting the
transmission order of the received packets and the packets which
have been decided as packets to be retransmitted, on the basis of
the additional information; and a transmission unit for transmitting, in the transmission
order set by the management unit, the data of packets other than
the packets which are decided as packets that cannot be in time
for reproduction at the receiving end, by the reproduction time
decision unit.
Claim 13
Dependent Claim
217 words
A data receiving apparatus for receiving data which are
transmitted from the transmitting end in units of packets, each
packet having additional information relating to its sequence
number, priority, and data reproduction time at the receiving end,
and successively reproducing the data for each packet, said
apparatus comprising: a receiving unit for receiving the packets transmitted from
the transmitting end; an error packet detection unit for detecting error packets in
which errors have occurred during transmission, and outputting
normal packets which have been transmitted without transmission
errors, on the basis of the data of the received packets; a reproduction time decision unit for detecting the
reproduction time given to each error packet detected by the
error packet detection unit and the arrival time of the error
packet at the receiving end, and setting the arrival time limit
based on the reproduction time, and deciding whether or not the
error packet has arrived at the receiving end before the arrival
time limit; and a retransmission instruction output unit for outputting a
retransmission request only for the error packet which has
arrived at the receiving end before the arrival time limit, to
the transmitting end, by indicating the sequence number of the
error packet, on the basis of the result of the decision in the
reproduction time decision unit.
Claim 14
Dependent Claim
287 words
A data transmission method for performing continuous data
transmission from the transmitting end to the receiving end in
units of packets, each packet having additional information
relating to its sequence number, priority, and data reproduction
time at the receiving end, while successively reproducing data of
packets arrived at the receiving end, said method comprising the
steps of: at the transmitting end, giving a data reproduction time and priority information to
each packet to be transmitted; and storing, as retransmission data, only data of packets the
priorities of which are equal to or higher than a predetermined
value, in a retransmission buffer; at the receiving end, when a transmission error is detected, detecting the
priority information of an error packet, the reproduction time of
the error packet, and the arrival time of the error packet; setting the arrival time limit of the error packet on the
basis of the reproduction time; and when the detected priority is equal to or higher than the
predetermined value and the error packet has arrived before the
arrival time limit, outputting a retransmission request for this
error packet to the transmitting end by indicating the sequence
number of this error packet; at the transmitting end, when data of the packet having the sequence number indicated
by the retransmission request from the receiving end is stored in
the retransmission buffer, retransmitting only data of the packet
the transmission time of which does not pass the reproduction
time, to the receiving end, while discarding data of the packet
the transmission time of which has passed the reproduction time;
and discarding the data stored in the retransmission buffer in
order starting from a packet which cannot be in time for
reproduction at the receiving end.
Claim 15
Dependent Claim
110 words
The data transmission method of Claim 14 wherein: at the transmitting end, additional information relating to
the sequence number, the priority, and the reproduction time of a
predetermined packet is embedded in a subsequent packet to be
transmitted after the predetermined packet; and at the receiving end, when a transmission error of the
predetermined packet has occurred and the additional information
of the predetermined packet has an error, a retransmission
request for the predetermined packet as an error packet is made
on the basis of the additional information of the predetermined
packet which is embedded in the subsequent packet, when the
subsequent packet transmitted after the predetermined packet is
received.
Claim 16
Dependent Claim
104 words
The data transmission method of Claim 15 wherein: at the transmitting end, the process of embedding the
sequence number of a predetermined high priority packet in a
subsequent packet which follows the predetermined high priority
packet is continuously performed until a high priority packet
next to the predetermined high priority packet is transmitted;
and at the receiving end, the sequence number of another packet
which is embedded in the received packet is extracted, and when a
transmission error has occurred in the packet of the extracted
sequence number, a retransmission request for this packet is made
by indicating the sequence number of this packet.
Claim 17
Dependent Claim
83 words
The data transmission method of Claim 15 wherein, at the
transmitting end, when additional information relating to the
sequence number and the reproduction time corresponding to each
packet is embedded in a subsequent packet to be transmitted after
the packet, a difference between additional information relating
to the sequence number and the reproduction time corresponding to
the subsequent packet and the additional information relating to
the sequence number and the reproduction time corresponding to
the previous packet is embedded as the additional information.
Claim 18
Dependent Claim
113 words
A data transmission method for performing data transmission
between a distribution server and a terminal through a relay
server in units of packets, and successively reproducing data of
packets received at the terminal, said method comprising the
steps of: when a transmission error has occurred between the relay
server and the terminal, performing retransmission of an error
packet by the relay server in response to a retransmission
request from the terminal; and when a transmission error has occurred between the
distribution server and the relay server, performing
retransmission of an error packet by the distribution server in
response to a retransmission request which has been transmitted
from the terminal through the relay server.
Claim 19
Dependent Claim
51 words
The data transmission method of Claim 18 wherein, when a
transmission error has occurred between the distribution server
and the relay server, a retransmission request is transmitted
from the relay server to the distribution server, and
retransmission of an error packet to the relay server is
performed by the distribution server.
Claim 20
Dependent Claim
256 words
A data transmission apparatus for relaying data which are
successively transmitted from a distribution server, in units of
packets each having additional information relating to its
sequence number, priority, data reproduction time at the
receiving end, said apparatus comprising: a receiving unit for receiving the packets transmitted from
the transmitting end; a priority decision unit for deciding the priority of each of
the received packets; a retransmission packet storage unit for storing packets the
priorities of which are equal to or higher than a predetermined
value, as retransmission packets, on the basis of the priority of
each packet decided by the priority decision unit; a retransmission instruction receiving unit for receiving a
retransmission request from a terminal at the receiving end; a retransmission decision unit for deciding whether
retransmission of the packet for which the retransmission request
has been made is to be performed or not, on the basis of the
retransmission request and the storage status of the
retransmission packets in the retransmission packet storage unit; a retransmission instruction output unit for outputting the
retransmission request for the error packet requested by the
terminal, to the distribution server, on the basis of the result
of the decision in the retransmission decision unit; a transmission queue management unit for setting the
transmission order of the received packets and the packets which
have been decided as packets to be retransmitted, on the basis of
the additional information; and a transmission unit for transmitting the data of these
packets in the transmission order set by the management unit.
Claim 21
Dependent Claim
338 words
A data transmission method for performing continuous data
transmission from the transmitting end to the receiving end in
units of packets, each packet having additional information
relating to its sequence number, priority, and data reproduction
time at the receiving end, while successively reproducing data of
packets received at the receiving end, said method comprising the
steps of: at the transmitting end, when a packet the priority of which is equal to or higher
than a predetermined value is transmitted as a high priority
packet, storing data of this high priority packet, as
retransmission data, in a retransmission buffer; managing the value of the transmitting end high priority
sequence number which corresponds to the number of transmitted
high priority packets, and the value of the sequence number of
the high priority packet so that these values are correlated with
each other; and transmitting a subsequent packet which follows the high
priority packet after embedding the value of the transmitting end
high priority sequence number in this subsequent packet; at the receiving end, extracting the value of the transmitting end high priority
sequence number which is embedded in the received packet; managing the value of the receiving end high priority
sequence number which corresponds to the number of received high
priority packets; when the value of the extracted transmitting end high
priority sequence number is not equal to the value of the
receiving end high priority sequence number, outputting a
retransmission request to the transmitting end, by indicating the
value of the transmitting end high priority sequence number which
is obtained on the basis of the value of the receiving end high
priority sequence number; and updating the value of the receiving end high priority
sequence number; at the transmitting end, only when data of the packet having the sequence number
corresponding to the value of the transmitting end high priority
sequence number which is indicated by the retransmission request
from the receiving end is stored in the retransmission buffer,
retransmitting the data of this packet to the receiving end.
Claim 22
Dependent Claim
178 words
The data transmission method of Claim 21 wherein: at the receiving end, when the value of the transmitting end
high priority sequence number embedded in the received packet is
not equal to the value of the receiving end high priority
sequence number, a retransmission request is output to the
transmitting end, by listing the values ranging from the value
obtained by adding 1 to the receiving end high priority sequence
number, to the value of the transmitting end high priority
sequence number, as the values of the transmitting end high
priority sequence numbers, or by designating the range as the
range of the values of the transmitting end high priority
sequence numbers; and at the transmitting end, the sequence numbers corresponding
to the values of the plural transmitting end high priority
sequence numbers which are indicated by the retransmission
request from the receiving end are retrieved, and only when data
of the packets having the sequence numbers obtained by the
retrieval are stored in the retransmission buffer, the data of
the packets are retransmitted to the receiving end.
Claim 23
Dependent Claim
117 words
The data transmission method of Claim 21 wherein: at the receiving end, the retransmission request is
performed continuously be several times, indicating the value of
a transmitting end high priority sequence number; and at the transmitting end, the sequence number corresponding
to the value of the transmitting end high priority sequence
number which is indicated by the retransmission request from the
receiving end is retrieved, and data of the packet having the
sequence number obtained by the retrieval is retransmitted to the
receiving end and, simultaneously, the correspondence between the
value of the sequence number obtained by the retrieval and the
value of the transmitting end high priority sequence number
indicated by the receiving end is deleted.
Claim 24
Dependent Claim
296 words
A data transmission apparatus for relaying data which are
successively transmitted from the transmitting end in units of
packets, each packet having additional information relating to
its sequence number, priority, data reproduction time at the
receiving end, said apparatus comprising: a receiving unit for receiving the packets transmitted from
the transmitting end; a transmission queue management unit for setting the
transmission order of the received packets and packets which are
decided as packets to be retransmitted; a transmission unit for transmitting data of these packets in
the transmission order set by the transmission queue management
unit; a priority decision unit for deciding the priority of each of
the received packets; a retransmission packet storage unit for storing packets the
priorities of which are equal to or higher than a predetermined
value, as retransmission packets, on the basis of the priority of
each packet decided by the priority decision unit; a sequence number management unit for managing the value of
the transmitting end high priority sequence number which
corresponds to the number of transmitted high priority packets,
and the value of the sequence number of the high priority packet
so that these values are correlated with each other; a high priority sequence number insertion unit for embedding
the value of the transmitting end high priority sequence number
in a subsequent packet which follows the high priority packet; a retransmission instruction receiving unit for receiving a
retransmission request indicating the high priority sequence
number, from a terminal at the transmitting end; and a retransmission decision unit for deciding whether
retransmission of the packet for which the retransmission request
has been made is to be performed or not, on the basis of the
retransmission request and the storage status of the
retransmission packets in the retransmission packet storage unit.
Claim 25
Dependent Claim
270 words
A data receiving apparatus for receiving data which are
transmitted from the transmitting end in units of packets, each
packet having additional intonation relating to its sequence
number, priority, and data reproduction time at the receiving end,
and successively reproducing the data for each packet, said
apparatus comprising: a receiving unit for receiving the packets transmitted from
the transmitting end; an error packet detection unit for detecting an error packet
in which an error has occurred during transmission, and
outputting a normal packet which has been transmitted without
transmission errors, and the value of the transmitting end high
priority sequence number which corresponds to the number of
transmitted high priority packets and is embedded in the normal
packet; a high priority sequence number management unit for managing
the value of the receiving end high priority sequence number
which corresponds to the number of normal high priority packets
which have been received without transmission errors, on the
basis of the output from the error packet detection unit; a retransmission sequence number decision unit for comparing
the value of the transmitting end high priority sequence number
from the error packet detection unit with the value of the
receiving end high priority sequence number, and when these
values are not equal, deciding the value of the transmitting end
high priority sequence number for which a retransmission request
is to be made, on the basis of the value of the receiving end
high priority sequence number; and a retransmission instruction output unit for outputting a
retransmission request to the transmitting end, by indicating the
value of the decided transmitting end high priority sequence
number.
Claim 26
Dependent Claim
94 words
A data structure of a packet for performing data
transmission from the transmitting end and the receiving end,
wherein: said packet comprises a header section containing relevant
information indicating the attribute of the packet, and a data
section containing data to be transmitted; and said header section comprises at least first and second
header information, amongst first header information indicating
the sequence number corresponding to the packet, second header
information indicating the priority of the packet, and third
header information indicating the reproduction time at the
receiving end, of the data to be transmitted.
Claim 27
Dependent Claim
28 words
The packet data structure of Claim 26 wherein the header
section of the packet includes attribute information of a packet
which has already been transmitted before the packet.
Claim 28
Dependent Claim
40 words
The packet data structure of Claim 27 wherein the header
section of the packet includes the first and second information
or the first and third information, as attribute information of a
packet which has already been transmitted before the packet.
Claim 29
Dependent Claim
50 words
The packet data structure of Claim 26 wherein the header
section of the packet includes the value of the high priority
sequence number corresponding to the number of high priority
packets which have been transmitted before the packet and having
the priorities equal to or higher than a predetermined value.
References Cited (Backward Citations)
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