The present disclosure relates to a transmission control device, a
10 transmission control method, a reception control device, and a reception control
method.
Background Art
[0002]
15 Recently, vartous technologies related to a wireless local area network
(LAN) have become widespread. For example, as a wireless LAN technology, a
protocol referred to as a block acknowledgement (hereinafter also referred as "block
ACK") for sequentially transmitting a plurality of pieces of data from a transmissionside
communication device and then collectively returning reception confirmation
20 from a reception-side communication device is used. For example, a method of
performing an acknowledgement associated with the most recently transmitted
transmission sequence indicator during block acknowledgement is disclosed (for
example, refer to Patent Literature I).
25
Patent Literature
[0003}
Citation List
Patent Literature 1: JP 2011-l25035A
30 Disclosure oflnvention
Technical Problem
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[0004]
However, even in the case in which a sequence number space is shared
among a plurality of pieces of data transmitted from the transmission-side
communication device, it is desired to provide a technology capable of performing
5 processing on desired data in the reception-side communication device.
Solution to Problem
[0005]
According to the present disclosure, there is provided a transmission control
10 device including: a communication control unit that controls transmission of a
plurality of pieces of data including respective sequence numbers; and a data
generation unit that generates, as information indicating one or a plurality of pieces
of data to be processed in a reception device among the plurality of pieces of data,
number information indicating the sequence numbers included in the one or plurality
15 of pieces of data to be processed. The communication control unit controls
transmission of the number information to the reception device.
[0006]
According to the present disclosure, there is provided a transmission control
method including: controlling transmission of a plurality of pieces of data including
20 respective sequence numbers; generating, as information indicating one or a plurality
of pieces of data to be processed in a reception device among the plurality of pieces
of data, number information indicating the sequence numbers included in the one or
plurality of pieces of data to be processed; and controlling transmission of the
number information to the reception device.
25 [0007]
According to the present disclosure, there is provided a reception control
device including: a communication control unit that controls reception, from a
transmission device, of number infonnation indicating sequence numbers included in
one or a plurality of pieces of data to be processed, as information indicating the one
30 or plurality of pieces of data to be processed among a plurality of pieces of data
including respective sequence numbers; and a data acquisition unit that acquires the
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number information.
[0008]
According to the present disclosure, there is provided a reception control
method including: controlling reception, from a transmission device, of number
5 information indicating sequence numbers included in one or a plurality of pieces of
data to be processed, as information indicating the one or plurality of pieces of data
to be processed among a plurality of pieces of data including respective sequence
numbers; and acquiring the number information.
10 Advantageous Effects oflnvention
[0009]
As described above, according to the present disclosure, even when a
sequence number space is shared among a plurality of pieces of data transmitted
from a transmission-side communication device, a technology capable of performing
Hi processing on desired data in a reception-side communication device is provided.
20
Note that the effects described above are not necessarily limitative. With or in the
place of the above effects, there may be achieved any one of the effects described in
this specification or other effects that may be grasped from this specification.
Brief Description of Drawings
[0010]
[FIG. I] FIG. I is a view illustrating a configuration example of a communication
system common to each embodiment ofthe present disclosure.
[FIG. 2] FIG. 2 is a view illustrating a configuration example of a communication
25 device.
[FIG. 3] FIG. 3 is a view for describing a sequence of a transmitting operation
according to a first embodiment of the present disclosure.
[FIG. 4] FIG. 4 is a view for describing a sequence of a receiving operation according
to the first embodiment of the present disclosure.
30 [FIG. 5] FIG. 5 is a view for describing a sequence of a receiving operation according
to the first embodiment ofthe present disclosure.
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[FIG. 6] FIG. 6 is a view for describing a sequence of a receiving operation according
to the first embodiment of the present disclosure.
[FIG. 7] FIG. 7 is a view illustrating a format configuration example of a general
aggregate data frame.
5 [FIG. 8] FIG. 8 is a view illustrating a format configuration example of a flush frame
according to the first embodiment of the present disclosure.
[FIG. 9] FIG. 9 is a view for describing a sequence of a transmitting operation
according to a second embodiment of the present disclosure.
[FIG. 1 0] FIG. I 0 is a view for describing a sequence of a receiving operation
10 according to the second embodiment ofthe present disclosure.
[FIG. II] FIG. II is a view illustrating a format configuration example of a beacon
signal according to a second embodiment of the present disclosure.
[FIG. 12] FIG. 12 is a view illustrating a configuration example of flush information
according to the second embodiment of the present disclosure.
15 [FIG. 13] FIG !3 is a view illustrating a header configuration example to which the
flush information of the present disclosure is added.
[FIG. 14] FIG. 14 is a view illustrating a flowchart of an operation related to a
transmission-side communication device.
[FIG. 15] FIG. 15 is a view illustrating a flowchart of an operation related to a
20 reception-side communication device.
[FIG. 16] FIG. 16 is a block diagram illustrating an example of a schematic
configuration of a smartphone.
[FIG. 17] FIG. 17 is a block diagram illustrating an example of a schematic
configuration of a car navigation device.
25 [FIG. 18] FIG. 18 is a block diagram illustrating an example of a schematic
configuration of a wireless access point.
30
Mode(s) for Carrying out the Invention
[0011]
Hereinafter, (a) preferred embodiment(s) of the present disclosure will be
described in detail with reference to the appended drawings. In this specification
5
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and the appended drawings, structural elements that have substantially the same
function and structure are denoted with the same reference numerals, and repeated
explanation of these structural elements is omitted.
[0012]
Note that, in this description and the drawings, structural elements that have
substantially the same function and structure are sometimes distinguished from each
other using different alphabets or numerals after the same reference sign. However,
when there is no need in particular to distinguish structural elements that have
substantially the same function and structure, the same reference sign alone is
10 attached.
[0013]
The description will be given in the following order.
1. Description of problem
2. Configuration common to each embodiment
15 3. first embodiment
4. Second embodiment
5. Application example
6. Conclusion
[0014]
20 <1. Description of problem>
Recently, various technologies related to wireless local area network (LAN)
have become widespread. For example, as a wireless LAN technology, a protocol
referred to as a block ACK for sequentially transmitting a plurality of pieces of data
from a transmission-side communication device and then collectively returning
25 reception confirmation from a reception-side communication device is used. In
such a protocol, a sequence number of a start data frame requesting
acknowledgement is described in a request frame of the block ACK, and the
reception-side communication device returns the sequence number of the data frame
received from this statiing sequence number in a bitmap format.
30 [0015]
In this protocol, for example, when unicast communication is performed, a
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sequence number is managed for each destination communication device, and the
sequence number is defined so that one is added each time a data frame and a
management frame are transmitted. On the other hand, when multicast
communication is performed, an implementation in which a single sequence number
5 space is shared for a plurality of multicast communications without preparing a
sequence number space for each of the multicast communications is possible. As
an example, a method of performing an acknowledgement associated with the most
recently transmitted transmission sequence indicator during a block
acknowledgement is disclosed (for example, JP 2011-125035A).
10 [0016]
However, if a single sequence number space is shared by a plurality of
multicast communications, a sequence number assigned to each multicast frame
becomes a toothless value. Therefore, although transfer of a certain multicast frame
is originally ended, because another multicast frame exists, a buffer of a reception-
15 side communication device cannot be flushed. As a result, a situation in which,
although reception of a frame to be received by itself is completed, an arrival of a
frame which does not need to be received by itself is continuously waited for may
occur. Here, flush means, for example, a process of opening data in a buffer or
delivering the data to an upper layer.
20 [0017]
When transmission of a management frame such as a beacon signal is
performed while data is being continuously transmitted from a transmission-side
communication device, inconsecutiveness may occur in a sequence number when a
sequence number for multicast communication is also shared for a management
25 frame. In the method of perfmming an acknowledgement associated with a
transmission sequence indicator as disclosed in the above literature, because a
transmission sequence number (TSN) is added for each request for a block
acknowledgement, the method cannot be used to flush data in internal sequence
number units of a block acknowledgement.
30 [0018]
<2. Configuration common to each embodiment>
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In the embodiments of the present disclosnre, a method for solving such a
problem is mainly proposed. Before describing each embodiment of the present
disclosure, a configuration common to each of the embodiments of the present
disclosure will be described first. FIG. 1 is a view illustrating a configuration
5 example of a communication system common to each of the embodiments of the
present disclosure. As illustrated in FIG. 1, a communication system 1 includes
communication devices 10-1 to 10-4 and constitutes a wireless network with the
communication devices 10-1 to 10-4. Although the communication system 1
includes four communication devices 10 in the example illustrated in FIG. 1, the
10 number of communication devices 10 included in the communication system 1 is not
particularly limited.
[0019]
The function of each of the communication devices 10-1 to 10-4 is not
limited. For example, the communication device 10-4 may function as an access
15 point. In that case, while using the communication device 10-4 as an access point,
the communication devices 10-1 to 10-3 can perform wireless communication under
the control of the access point (the communication device 1 0-4). Alternatively, the
access point may not be particularly present
20
[0020]
As illustrated in FIG. 1, for example, the communication device 10-1 may
communicate with the communication device 10-2 and the communication device
10-4. The communication device I 0-2 may communicate with the communication
device 10-1, the communication device 10-3, and the communication device 10-4.
The communication device 10-3 may communicate with the communication device
25 10-2 and the communication device 10-4. The communication device 10-4 may
communicate with the communication device 10-1, the communication device 10-2,
and the communication device 10-3.
[0021]
Here, as described above, when the communication device 10-4 functions as
30 an access point, first multicast data may be transmitted from the communication
device l 0-4 to the communication device 10-1 and the communication device 1 0-2.
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Also, second multicast data may be transmitted from the communication device 10-4
to the communication device 10-2 and the communication device 10-3. Further,
third multicast data may be transmitted from the communication device I 0-4 to the
communication device 10-1 and the communication device 10-3.
5 [0022]
Each of the communication devices I 0-1 to 10-4 may also function as a
transmission-side communication device (or a transmission control device) or may
also function as a reception-side communication device (or a reception control
device). Next, a configuration example of the communication device I 0 will be
10 described. FIG. 2 is a view illustrating a configuration example of the
communication device l 0. Here, although the communication device 10-4, which
serves as an access point, and the other communication devices 10-1 to 10-3 are
described as having the same configuration for convenience, the communication
device I 0-4 may be connected to the Internet via a wired network when, for example,
15 the communication device 10-4 functions as an access point.
[0023]
As illustrated in FIG. 2, the communication device 10 includes an interface
unit 201, a transmitting buffer unit 202, a buffer management unit (storage control
unit) 203, a transmission data frame construction unit 204, a wireless signal
20 transmission processing unit (communication control unit) 205, a multicast
transmission sequence management unit 206, and a flush frame construction unit
(data generation unit) 207. A flush frame will be described below.
[0024]
Further, the communication device 10 includes an access control unit 208,
25 an antenna control unit 209, and antenna elements 210A and 2IOB. Further, the
communication device 10 includes a wireless signal reception processing unit
(communication control unit) 211, a reception data frame extraction unit (data
acquisition unit) 212, a receiving buffer unit 213, a flush frame extraction unit 214,
and a multicast reception sequence management unit 215.
30 [0025]
The interface unit 20 I includes an input unit for inputting information from
SP3G3752WOOO
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a user or an output unit for outputting information to the user. The transmitting
buffer unit 202 stores data to be transmitted to another communication device. The
buffer management unit 203 manages a use status of an internal memory space
arranged as a buffer. The transmission data frame construction unit 204 constructs
5 transmission data having a predete1mined wireless transmission data frame format.
The wireless signal transmission processing unit 205 converts a data frame to be
transmitted from a baseband signal into a high-frequency signal.
[0026]
The multicast transmission sequence management unit 206 manages a
10 communication sequence for multicast communication. The flush frame
construction unit 207 constructs a flush frame for multicast communication. The
access control unit 208 controls access of communication on a wireless transmission
path based on a predetermined wireless communication protocol. The antenna
control unit 209 transmits a signal on the wireless transmission path and controls an
15 antenna that receives the signal from the wireless transmission path. The antenna
elements 21 OA and 2lOB transmit or receive the signals as a plurality of antenna
elements.
[0027]
The wireless signal reception processing unit 21 I converts a high-frequency
20 signal received via the antenna into a baseband signal. The reception data frame
extraction unit 212 extracts data from the baseband signal as a predetermined data
frame. The receiving buffer unit 2 I 3 temporarily stores received user data until a
predetermined unit of data that can be output to the interface unit is collected. The
flush frame extraction unit 214 extracts the flush frame according to the present
25 disclosure from the received baseband signal. The multicast reception sequence
management unit 215 manages the reception sequence of the multicast
communication.
[0028]
<3. First embodiment>
30 Next, the first embodiment of the present disclosure will be described. FIG.
3 is a view for describing a sequence of a transmitting operation according to the first
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embodiment of the present disclosure. As illustrated in FIG 3, in the
communication system I, three flows of multicast communication MA, MB, and MC
are performed. Pieces of multicast data MA#l to MA#4 are stored as the multicast
communication MA in the transmitting buffer, Pieces of multicast data MB#l and
5 MB#2 are stored as the multicast communication MB in the transmitting buffer, and
pieces of multicast data MC#l and MC#2 are stored as the multicast communication
MC in the transmitting buffer.
[0029]
ln the transmission-side communication device, the multicast transmission
10 sequence management unit 206 adds a sequence number for multicasting to the
above multicast data, and the wireless signal transmission processing unit 205
controls transmission of the multicast data. First, the transmission-side
communication device adds a sequence number SN:l to the multicast data MA#I
and transmits the multicast data MA#I, adds a sequence number SN:2 to the
15 multicast data MB#l and transmits the multicast data MB#I, and adds a sequence
number SN:3 to the multicast data MC#l and transmits the multicast data MC#L
As described above, although an individual sequence number is added to each piece
of multicast data to be transmitted, the sequence number becomes an inconsecutive
value for each flow of multicast communication.
20 [0030]
Further, the transmission-side communication device adds a sequence
number SN:4 to the multicast data MA#2 and transmits the multicast data MA#2,
adds a sequence number SN:5 to the multicast data MA#3 and transmits the multicast
data MA#3, adds a sequence number SN:6 to the multicast data MB#2 and transmits
25 the multicast data MB#2, adds a sequence number SN:7 to the multicast data MA#4
and transmits the multicast data MA#4, and adds a sequence number SN:S to the
multicast data MC#2 and transmits the multicast data MC#2.
[0031]
Here, in the transmission-side communication device, for example, an end
30 of the transmission of the multicast data stored in the transmitting buffer is a trigger
for the wireless signal transmission processing unit 205 to control transmission of the
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flush frame according to the present disclosure. The flush frame is information
(number information) indicating one or a plurality of pieces of data to be processed
in the reception-side communication device among the multicast data and indicates a
sequence number included in each of the one or plurality of pieces of data to be
5 processed.
[0032]
The wireless signal transmission processing unit 205 may control
transmission by multicast communication of the flush frame. Further, the flush
frame may be defined for each flow of the multicast communication. For example,
10 as illustrated in FIG. 3, in the transmission-side communication device, the flush
frame construction unit 207 generates a flush frame: Flash A of the multicast
communication MA, a flush frame: Flash B of the multicast communication MB, and
a flush frame: Flash C of the multicast communication MC.
15
[0033]
When the flush frames are subject to multicast transmission, a
predetermined sequence number may not he added to the flush frames, but a
predetermined sequence number may be added thereto as a type of management
frame and sent. Specifically, as illustrated in FIG. 3, a sequence number SN:9 is
added to Flash A, a sequence number SN: I 0 is added to Flash B, and a sequence
20 number SN:IO is added to Flash C. Then, the wireless signal transmission
processing unit 205 controls transmission ofthe flush frames.
[0034]
According to the transmission-side communication device, even when a
sequence number space is shared among the plurality of pieces of multicast data
25 transmitted from the transmission-side communication device, predetermined
processing on desired data can be performed in the reception-side communication
device.
[0035]
In the example illustrated in FIG. 3, each of a plurality of data frames
30 transmitted from the transmission-side communication device to the reception-side
communication device is described independently. However, aggregation
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processing may be performed on the plurality of data frames as necessary in the
transmission-side communication device, and the plurality of data frames may be
combined as a single physical layer (PHY) burst and transmitted to the reception-side
communication device.
5 [0036]
FIG. 4 is a view for describing a sequence of a rece1vmg operation
according to the first embodiment of the present disclosure. FIG. 4 illustrates a
receiving operation of the reception-side communication device performing the
multicast communication MA and illustrates an operation of extracting only
10 multicast data to be processed from multicast data transmitted, with inconsecutive
sequence numbers attached thereto, from the transmission-side communication
device and reconstructing the data. First, multicast data received by the multicast
communication is stored in the receiving buffer unit 213.
15
[0037]
For example, as illustrated in FIG. 4, in the reception-side communication
device, the wireless signal reception processing unit 211 controls reception of the
pieces of multicast data MA-l to MA-4 related to the multicast communication MA,
and the buffer management unit 203 stores the pieces of multicast data MA-l to MA-
4 to be received from reception data extracted by the reception data frame extraction
20 unit 212 in the receiving buffer unit 213. After the multicast communication ends,
25
in the reception-side communication device, the wireless signal reception processing
unit 21 I controls reception of a flush frame transmitted from the transmission-side
communication device.
[0038]
As illustrated in FIG. 4, it is assumed that the flush frame: Flash A is
received in the reception-side communication device. The multicast reception
sequence management unit 215 may acquire the flush frame and specify the pieces of
multicast data MA-l to MA-4 to which sequence numbers SN:l, SN:4, SN:S, and
SN :7 indicated by the flush frame are attached as multicast data to be processed.
30 [0039]
According to the configuration of the reception-side communication device,
SP363752WOOO
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even when a sequence number space is shared among the plurality of piece of
multicast data transmitted from the transmission-side communication device,
predetermined processing on desired data can be performed in the reception-side
communication device. Further, in the reception-side communication device,
5 predetermined processing may be performed on the specified pieces of multicast data
MA -1 to MA -4 to be processed.
[0040]
The predetermined processing is not limited. For example, in the
reception-side communication device, the multicast reception sequence management
10 unit 215 may determine whether the pieces of multicast data MA-l to MA-4 to be
processed are received with reference to the flush frame. Then, when it is
determined that the pieces of multicast data MA-l to MA-4 to be processed are
received, the buffer management unit 203 may deliver the pieces of multicast data
MA-l to MA-4 to be processed from the receiving buffer uuit 213 to an upper layer
15 application (the interface unit 201 ).
[0041]
Further, for example, when it is determined that the pieces of multicast data
MA-l to MA-4 to be processed are received, the buffer management unit 203 may
flush the pieces of multicast data MA-l to MA-4 to be processed from the receiving
20 buffer unit 213.
[0042]
Further, the multicast reception sequence management unit 215 may
determine whether reception of the pieces of multicast data MA-l to MA-4 to be
processed is completed within a predetermined period with reference to the flush
25 frame. Further, when il is determined that the reception of the pieces of multicast
data MA-l to MA-4 to be processed is not completed even after the lapse of the
predetennined period, the buffer management unit 203 may flush received data to be
processed among the pieces of multicast data MA-l to MA-4 to be processed from
the receiving buffer unit 213.
30 [0043]
FlG. 5 IS a v1ew for describing a sequence of a receiving operation
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according to the first embodiment of the present disclosure. FIG. 5 illustrates a
receiving operation of the reception-side communication device performing the
multicast communication MB and illustrates an operation of extracting only
multicast data to be processed from multicast data transmitted, with inconsecutive
5 sequence numbers attached thereto, from the transmission-side communication
device and reconstructing the data. First, multicast data received by the multicast
communication is stored in the receiving buffer unit 213.
[0044]
For example, as illustrated in FIG. 5, in the reception-side communication
10 device, the wireless signal reception processing unit 211 controls reception of the
pieces of multicast data MB-1 and MB-2 related to the multicast communication MB,
and the buffer management unit 203 stores the pieces of multicast data MB-1 and
MB-2 to be received from reception data extracted by the reception data frame
extraction unit 212 in the receiving buffer unit 213. After the multicast
15 commooication ends, in the reception-side communication device, the wireless signal
reception processing unit 211 controls reception of the flush frame transmitted from
the transmission-side communication device.
[0045]
As illustrated in FIG. 5, it is assumed that the flush frame: Flash B is
20 received in the reception-side communication device. The multicast reception
sequence management unit 215 may acquire the flush frame and specify the pieces of
multicast data MB-1 and MB-2 to which sequence numbers SN:2 and SN:6 indicated
by the flush fi·ame are attached as multicast data to be processed.
25
[0046]
According to the configuration of the reception-side communication device,
even when a sequence number space is shared among the plurality of multicast data
transmitted from the transmission-side communication device, predetermined
processing on desired data can be perfonned in the reception-side communication
device. Further, in the reception-side communication device, predetem1ined
30 processing may be performed on the specified pieces of multicast data MB-1 and
MB-2 to be processed.
SP363752WOOO
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[0047]
The predetermined processmg 1s not limited. For example, in the
reception-side communication device, the multicast reception sequence management
unit 215 may determine whether the pieces of multicast data MB-1 and MB-2 to be
5 processed are received with reference to the flush frame. Then, when it is
determined that the pieces of multicast data MB-1 and MB-2 to be processed are
received, the buffer management unit 203 may deliver the pieces of multicast data
MB-1 and MB-2 to be processed from the receiving buffer unit 213 to an upper layer
application (the interface unit 201).
10 [0048]
Further, for example, when it is determined that the pieces of multicast data
MB-1 and MB-2 to be processed are received, the buffer management unit 203 may
flush the pieces of multicast data MB-1 and MB-2 to be processed from the receiving
buffer unit 213.
15 [0049]
Further, the multicast reception sequence management unit 215 may
determine whether reception of the pieces of multicast data MB-1 and MB-2 to be
processed is completed within a predetermined period with reference to the flush
frame. Further, when it is determined that the reception of the pieces of multicast
20 data MB-1 and MB-2 to be processed is not completed even after the lapse of the
predetermined period, the buffer management unit 203 may flush received data to be
processed of the pieces of multicast data MB-1 and MB-2 to be processed from the
receiving buffer unit 213.
[0050]
25 FIG. 6 is a VIeW for describing a sequence of a receiving operation
according to the first embodiment of the present disclosure. FIG. 6 illustrates a
recelV!ng operation of the reception-side communication device performing the
multicast communication MC and illustrates an operation of extracting only
multicast data to be processed from multicast data transmitted, with inconsecutive
30 sequence numbers attached thereto, fi-om the transmission-side communication
device and reconstructing the data. First, multicast data received by the multicast
16/45
communication is stored in the receiving buffer unit 2 I 3.
[0051]
SP363752WOOO
For example, as illustrated in FIG. 6, in the reception-side communication
device, the wireless signal reception processing unit 2 I I controls reception of the
5 pieces of multicast data MC-1 and MC-2 related to the multicast communication MC,
and the buffer management unit 203 stores the pieces of multicast data MC-1 and
MC-2 to be received from reception data extracted by the reception data frame
extraction unit 212 in the receiving buffer unit 213. After the multicast
communication ends, in the reception-side communication device, the wireless signal
10 reception processing unit 2 I I controls reception of the flush frame transmitted from
the transmission-side communication device.
[0052]
As illustrated in FIG. 6, it is assumed that the flush frame: Flash C is
received in the reception-side communication device. The multicast reception
15 sequence management unit 215 may acquire the flush frame and specify the pieces of
multicast data MC-1 and MC-2 to which sequence numbers SN:3 and SN:8 indicated
by the flush frame are attached as multicast data to be processed.
[0053]
According to the configuration of the reception-side communication device,
20 even when a sequence number space is shared among the plurality of pieces of
multicast data transmitted from the transmission-side communication device,
predetermined processing on desired data can be performed in the reception -side
communication device. Further, in the reception-side communication device,
predetermined processing may be perfonned on the specified pieces of multicast data
25 MC-1 and MC-2 to be processed.
[0054]
The predetermined processing IS not limited. For example, in the
reception-side communication device, the multicast reception sequence management
unit 215 may determine whether the pieces of multicast data MC-1 and MC-2 to be
30 processed are received with reference to the flush frame. Then, when it is
detennined that the pieces of multicast data MC-1 and MC-2 to be processed arc
5
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received, the buffer management unit 203 may deliver the pieces of multicast data
MC-1 and MC-2 to be processed from the receiving buffer unit 213 to an upper layer
application (the interface unit 201).
[0055]
Further, for example, when it is determined that the pieces of multicast data
MC-1 and MB-C to be processed are received, the buffer management unit 203 may
flush the pieces of multicast data MC-1 and MC-2 to be processed from the receiving
buffer unit 213.
[0056]
10 Further, the multicast reception sequence management unit 215 may
detennine whether reception of the pieces of multicast data MC-1 and MC-2 to be
processed is completed within a predetermined period with reference to the flush
frame. Further, when it is determined that the reception of the pieces of multicast
data MC-1 and MC-2 to be processed is not completed even after the lapse of the
15 predetermined period, the buffer management unit 203 may flush received data to be
processed of the pieces of multicast data MC-1 and MC-2 to be processed from the
receiving buffer unit 213.
[0057]
Although the case in which a flush frame of a single flow is received is
20 illustrated in FIGS. 4 to 6, it is also assumed that a flush frame for each flow is
received. In such a case, the multicast reception sequence management unit 215
may determine whether one or a plurality of pieces of data to be processed related to
all flows are received with reference to a flush frame for each of the flows. Also,
when it is determined that the one or plurality of pieces of data to be processed
25 related to all of the flows are received, the buffer management unit 203 may flush the
one or plurality of pieces of data to be processed related to all of the flows from the
receiving buffer unit 213.
[0058]
TI1e multicast reception sequence management unit 215 may determine
30 whether one or a plurality of pieces of data to be processed related to some of the
flows are received with reference to the flush frame for each of the flows. When it
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is determined that the one or plurality of pieces of data to be processed related to
some of the flows are received, the buffer management unit 203 may flush the one or
plurality of pieces of data to be processed related to some of the flows from the
receiving buffer unit 213 and may not flush the one or plurality of pieces of data to
5 be processed related to remaining flows from the receiving buffer unit 213.
[0059]
FIG 7 is a view illustrating a format configuration example of a general
aggregate data frame. In the example illustrated in FIG. 7, as a single PHY burst, a
MAC Protocol Data Unit (MPDU), which is a plurality of pieces of user data, is
10 configured as an aggregated MPDU (A-MPDU) sub-frame. The A-MPDU subframe
has an MPDU delimiter, an MPDU, and padding.
[0060]
Each MPDU has a MAC header, a frame body, and a frame check sequence
(FCS), and a fragment number and a sequence number are stored in a sequence
15 control part of the MAC header. That is, a single sequence number is added to a
single piece of user data included in a single MPDU, and the piece of user data is
transferred.
[0061]
FIG. 8 is a view illustrating a format configuration example of the flush
20 frame according to the first embodiment of the present disclosure. The flush frame
is transmitted as a management frame handled as a single MPDU, a flush control
field is configured as a payload body in the MAC header, and an FCS is added
thereto. The flush control field includes a control parameter including various
pieces of control information, a flow ID for identifying a flow, a start sequence
25 number indicating the start of a sequence number to be flushed, a sequence number
bitmap indicating a predetennined number starting from the start sequence number,
and the like.
[0062]
The first embodiment of the present disclosure has been described above.
30 According to the first embodiment of the present disclosure, even when unreachable
multicast data is present, a sequence number thereof may be specified. Here, the
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reception-side communication device may return block acknowledgement to the
transmission-side communication device as necessary and receive re-transmitted data.
[0063]
Further, an example in which a flush frame is transmitted with an end of
5 transmission of a series of data stored in the transmitting buffer unit 202 as a trigger
has been described above. However, the trigger for the transmission of the flush
frame is not particularly limited. For example, the trigger for the transmission of
the flush frame may be a predetermined data transmission being performed or a lapse
of a predetermined time after first multicast data is transmitted.
10 [0064]
Further, an operation of a communication device that functions as a
transmission-side communication device and an operation of a communication
device that functions as a reception-side communication device among the
communication devices 10-1 to 10-4 have been separately described above.
15 However, each of the communication devices I 0-1 to l 0-4 may have the functions of
both the transmission-side communication device and the reception-side
communication device or may have a function of only one of the transmission-side
communication device and the reception-side communication device.
[0065]
20 <4. Second embodiment>
Next, the second embodiment of the present disclosure will be described.
FIG. 9 is a view for describing a sequence of a transmitting operation according to
the second embodiment of the present disclosure. In the second embodiment of the
present disclosure, when a transmission-side communication device is operating as
25 an access point that transmits a predetermined beacon signal, number information
(hereinafter, also referred to as "flush information") is added to the beacon signal,
and a reception-side communication device is notified of the flush information at a
predetermined cycle by the beacon signal. Referring to FIG. 9, multicast
communication MD is performed from the transmission-side communication device,
30 and a flow of the multicast communication MD is present.
[0066]
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Here, although an access point of a wireless network transmits a beacon
signal at a predetermined cycle, the beacon signal may be present as a management
frame. Therefore, the multicast transmission sequence management unit 206 adds a
predetermined sequence number to a beacon signal, and the wireless signal
5 transmission processing unit 205 controls transmission of the beacon signal to which
the sequence number is added. Here, a sequence number SN:l is added to a beacon
signal and the beacon signal is transmitted, a sequence number SN:2 is added to
multicast data MD-! and the multicast data MD-! is transmitted, and a sequence
number SN:3 is added to multicast data MD-2 and the multicast data MD-2 is
10 transmitted.
[0067]
A sequence number SN :4 is added to another management frame and the
other management frame is transmitted, a sequence number SN :5 is added to
multicast data MD-3 and the multicast data MD-3 is transmitted, a sequence number
15 SN:6 is added to multicast data MD-4 and the multicast data MD-4 is transmitted,
and a sequence number SN:7 is added to multicast data MD-5 and the multicast data
MD-5 is transmitted. Also, a sequence number SN:8 is added to another
management frame and the other management frame is transmitted. Then, flush
information: Flash D of the present disclosure is added to the next beacon signal and
20 the beacon signal is transmitted.
[0068]
FIG. I 0 is a v1ew for describing a sequence of a rece1vmg operation
according to the second embodiment of the present disclosure. FIG. 10 illustrates a
receiving operation of the reception-side communication device performing the
25 multicast communication MD and illustrates an operation of reconstructing data by
extracting only multicast data to be processed from data received by the reception
data frame extraction unit 212 from multicast data sent from the transmission-side
communication device as inconsecutive sequence numbers and reconstructing the
data. First, the multicast data to be received, received by the multicast
30 communication, is stored in the receiving buffer unit 213.
[0069]
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As illustrated in FIG I 0, it is assumed that a beacon signal in which the
flush information: Flash D is set is received in the reception-side communication
device. The multicast reception sequence management unit 215 may extract the
flush information: Flash D from the beacon signal and specify the pieces of multicast
5 data MA-l to MA-5 to which the sequence numbers SN:2, SN3, SNS, SN6 and SN7
indicated by the flush information are attached as multicast data to be processed.
[0070]
As in the first embodiment of the present disclosure, according to the
configuration of the reception-side communication device, even when a sequence
10 number space is shared among the plurality of pieces of multicast data transmitted
from the transmission-side communication device, predetermined processing can be
performed on desired data in the reception-side communication device. Further, in
the reception-side communication device, predetermined processing may be
performed on the specified multicast data MA-l to MA-5 to be processed. As in
15 the first embodiment of the present disclosure, the predetermined processing is not
limited.
[0071]
FIG 1 1 illustrates a format configuration example of a beacon signal
according to the second embodiment of the present disclosure. As illustrated in FIG
20 II, a beacon signal is transmitted as a management frame handled as a single MPDU
and is configured as an FCS in a payload of the beacon signal in a MAC header.
The beacon payload includes information for setting various parameters, and flush
information according to the second embodiment may also be included therein.
[0072]
25 FIG 12 is a vtew illustrating a configuration example of the flush
information according to the second embodiment of the present disclosure. The
flush information includes an element type for designating an element type, a length
indicating a length of the flush information, a control parameter including various
pieces of control information, a flow ID for identifying a flow, a start sequence
30 number indicating a start of a sequence number to be flushed, and a sequence number
bit map indicating a predetermined number starting from the start sequence number.
SP363752WOOO
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[0073]
FIG. 13 is a view illustrating a header configuration example to which the
flush information of the present disclosure is added. In the example illustrated in
FIG. 13, a flush control header is added in front of or the end of an A-MPDU sub-
5 frame in which an MPDU, wbich is a plurality of pieces of user data, is aggregated as
a single PHY burst.
[0074]
The flush control header includes a control parameter including various
pieces of control information, a flow ID for identifYing a flow, a start sequence
10 number indicating a start of a sequence number to be flushed, and flush information
(for example, a sequence number bitmap indicating a predetermined number starting
from the start sequence number). Further, a header check sequence for determining
whether an error occurs in the header portion may be added to the flush control
header.
15 [0075]
FIG. 14 is a view illustrating a flowchart of an operation related to a
transmission-side communication device. The transmission-side communication
device determines whether data to be transmitted is accepted from an application
device connected thereto via an interface (S 10 I), and when the data to be transmitted
20 is accepted, stores the data in a transmitting buffer (S!02). Further, the
transmission-side communication device grasps a use status of a wireless
transmission path (S 1 03), and, when the transmission path is available at a target
beacon transmission time: TBTT (S I 04), acquires a beacon parameter (S I 05).
[0076]
25 Then, the transmission-side communication device sets a transmission
30
sequence number of a beacon signal which is a management frame (S I 06), transmits
the beacon signal for which the transmission sequence number is set (S I 07), and
saves the latest sequence number added to the transmitted beacon signal (S I 08).
[0077]
If management data is present in the transmitting buffer (Sl09), the
transmission-side communication device acquires transmission sequence number
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information (SilO), transmits management data, in which a value obtained by
incrementing the latest sequence number is set, as a frame (SIll), and saves the
latest sequence number added to the transmitted management frame (S 112). Here,
when multicasting or broadcasting the management data, the frame is transmitted
5 using a sequence number for multicasting.
[0078]
Then, when transmission data of multicast communication is stored in the
transmitting buffer (Sll3), the transmission-side communication device acquires
sequence number information for multicasting (S 114), transmits multicast data, for
10 which a value obtained by incrementing the sequence number is set, as a frame
(S 115), and saves the latest sequence number added to the transmitted management
frame (S 116).
[0079]
Further, the transmission-side communication device saves the sequence
Hi number in association with a transmission sequence number corresponding to a flow
for the multicast communication (S 11 7). That is, when a flow of a plurality of
multicast communications is shared, a value of a sequence number transmitted for
each of the flows of the multicast is saved.
20
[0080]
Then, when transmission of a senes of multicast communications rs
completed for each of the multicast flows (SI18), the transmission-side
communication device checks the use of the flush frame of the present disclosure
(S 119), and when corresponding to the flush frame (S 120), the transmission-side
communication device acquires information of the transmitted sequence number
25 corresponding to the flow of the multicast communication (S 121) and constructs a
flush frame as a frame of management data (S 122). Although an example of
constructing a flush frame is shown here, when a beacon signal in which flush
information is set is transmitted, a beacon signal in which flush information is set
may be constructed.
30 [0081]
If data to be unicast-transmitted is present in the transmitting buffer (Sl23),
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the transmission-side communication device acqmres a transmission sequence
number corresponding to a destination reception-side communication device (8 124),
transmits unicast data, in which a value obtained by incrementing the sequence
number is set, as a frame (8125), and saves the latest sequence number
5 corresponding to the reception-side communication device (8126).
[0082]
Further, when the transmission-side communication device receives an ACK
frame addressed to itself (8 127), if it is determined that unreachable data is present
therein from information of the ACK frame (8 128), the transmission-side
10 communication device extracts the unreachable data from the transmitting buffer
(S 129) and re-transmits the data (8 130). On the other hand, if it is determined that
unreachable data is not present (if receipt of all data is confirmed), the transmissionside
communication device deletes data related to the sequence of the multicast
communication from the transmitting buffer (8 131 ).
15 [0083]
FIG. 15 is a view illustrating a flowchart of an operation related to the
reception-side communication device. When the reception-side communication
device receives (unicast) data addressed to itself (8151), the reception-side
communication device acquires reception sequence number information for unicast
20 (S152), and if it is determined that unreachable data is received from the value for
the unicast sequence number included in the received data (S 153), the reception-side
communication device stores the received data in the receiving buffer (8154).
[0084]
For example, there is a case in which the reception-side communication
25 device determines that additional received data is not sent from information such as
More Data Bit in header information of a data frame. In such a case, the receptionside
communication device determines that reception of a series of data is completed
(SI55), delivers the data to an upper layer (SI56), and flushes data from the start
sequence number to the latest sequence number from the receiving buffer (8157).
30 On the other hand, when the reception of the series of data is not completed, the
reception-side communication device activates a reception unicast timer (8 158).
SP363752WOOO
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[0085]
When multicast data addressed to itself is received in the reception-side
communication device (S 159), the reception-side communication device acquires
reception sequence number information for multicast (S160). Next, when it is
5 determined that unreachable data is received from a value of a multicast sequence
number included in the received data (S 161 ), the reception-side communication
device stores the received data in the receiving buffer (S162), and updates
information ofthe reception sequence number for multicast (S 163). Here, when the
reception is completed with inconsecutive sequence numbers (S 164), the reception-
10 side communication device activates a reception multicast timer (S 165).
[0086]
On the other hand, when all data of the multicast communication is received
with consecutive sequence numbers, the reception-side communication device, for
example, determines that a series of the received data is completed from information
15 such as More Data Bit in the header information ofthe data frame in some cases. In
such a case, the reception-side communication device shifts the operation to S171.
[0087]
When a flush frame of multicast communication addressed to itself is
received in the reception-side communication device (S 166), the reception -side
20 communication device extracts a list of maps of sequence numbers that can be
flushed in the multicast communication from information of flush sequence numbers
of the multicast communication (S 167). Then, the reception-side communication
device temporarily saves the sequence numbers (S 168) and acquires a list of received
numbers of the multicast communication received by itself (Sl69).
25 [0088]
Here, if reception of all of the series of sequence numbers of the multicast
communication is completed (S 170), the reception-side communication device may
perform a process of delivering the series of multicast data to an upper layer (S 171 ).
When the multicast data is delivered to the upper layer, for example, control may be
30 performed such that image information is output to a display connected thereto via an
interface. Further, the reception-side communication device flushes the received
26/45
data from the receiving buffer of the sequence numbers (S 172).
[0089]
SP363752WOOO
If reception setting of another multicast communication is not performed
(8173), the reception-side communication device flushes received data from the start
5 sequence number up to the latest sequence number (8174). Alternatively, if a
flushable sequence number of a frame to be used other than the multicast
communication is added to the flush frame, the reception-side communication device
may flush the frame from the receiving buffer.
10
[0090]
On the other hand, it is assumed that data of a series of sequence numbers of
the multicast communication is not available. In such a case, when the reception
multicast timer times out (8175), the reception-side communication device displays a
reception error of the multicast frame (8 176) and reads a series of sequence numbers
of the multicast communication which is temporarily saved (8 177). Then, the
15 reception-side communication device shifts the operation to S 172 and flushes
received data corresponding to the sequence numbers from the receiving buffer.
[0091]
When the reception unicast timer times out (8 178), the reception-side
communication device displays a reception error of the unicast frame (8179). Then,
20 the reception-side communication device shifts the operation to S174 and flushes the
received data from the start sequence number up to the latest sequence number from
the receiving buffer.
25
[0092]
<5. Application examples>
The technology according to the present disclosure is applicable to various
products. In one example, the communication device I 0 may be implemented as a
mobile terminal such as smartphones, tablet personal computers (PCs), notebook PCs,
portable game terminals, or digital cameras, a fixed-type terminal such as television
receivers, printers, digital scanners, or network storages, or a car-mounted terminal
30 such as car navigation de"vices. ln addition, the communication device I 0 may be
implemented as a terminal (also referred to as machine type communication (MTC)
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terminal) which performs machine-to-machine (M2M) communication, such as smart
meters, vending machines, remote monitoring devices, and point of sale (POS)
terminals. Furthermore, the communication device I 0 may be a wireless
communication module mounted in such terminals (e.g., integrated circuit modules
5 configured in one die).
[0093]
On the other hand, in one example, the communication control device may
be implemented as a wireless LAN access point (also referred to as a wireless base
station) having or not having a router function. In addition, the communication
10 control device may be implemented as a mobile wireless LAN router. Furthermore,
the communication control device may be a wireless communication module
mounted on such devices (e.g., integrated circuit modules configured in one die).
[0094]
15
[ 5-L First application example]
FIG 16 is a block diagram illustrating an example of a schematic
configuration of a smartphone 900 to which the technology of the present disclosure
can be applied. The smartphone 900 is configured to include a processor 901, a
memory 902, a storage 903, an externally connected interface 904, a camera 906, a
sensor 907, a microphone 908, an input device 909, a display device 910, a speaker
20 911, a wireless communication interface 913, an antenna switch 914, an antenna 915,
a bus 91 7, a battery 918, and an auxiliary controller 919.
[0095]
The processor 90 I may be, in one example, a central processing unit (CPU)
or a system on chip (SoC), and controls functions of an application layer and other
25 layers of the smartphone 900. The memory 902 includes a random access memory
(RAM) and a read only memory (ROM), and stores programs executed by the
processor 90 I and data. The storage 903 can include a storage medium such as a
semiconductor memory or a hard disk. The externally connected interface 904 is an
interface for connecting an externally attached device such as a memory card or a
30 universal serial bus (USB) device to the smartphone 900.
[0096]
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The camera 906 has, in one example, an image sensor such as a charge
coupled device (CCD) or a complementary metal oxide semiconductor (CMOS), and
generates a captured image. TI1e sensor 907 can include a sensor group including,
in one example, a positioning sensor, a gyro sensor, a geomagnetic sensor, an
5 acceleration sensor, and the like. The microphone 908 converts voice input to the
smartphone 900 into an audio signal. The input device 909 includes, in one
example, a touch sensor that detects touches on a screen of the display device 910, a
key pad, a keyboard, buttons, switches, and the like, and accepts an operation or
information input from a user. The display device 910 has a screen such as a liquid
10 crystal display (LCD) or an organic light emitting diode (OLED) display, and
displays an output image of the smartphone 900. The speaker 911 converts an
audio signal output from the smartphone 900 into voice.
[0097]
The wireless communication interface 913 supports one or more wireless
15 LAN standards such as IEEE 802.1la, lib, llg, lin, llac, and Had, and executes
wireless LAN communication. The wireless communication interface 913 can
communicate with other devices via a wireless LAN access point in the infrastructure
mode. In addition, the wireless communication interface 913 can directly
communicate with other devices in a direct communication mode such as an ad hoc
20 mode, and Wi-Fi Direct (registered trademark). In Wi-Fi Direct mode, unlike ad
hoc mode, one of two terminals operates as an access point, but communication is
performed directly between the terminals. The wireless communication interface
9!3 can typically include a baseband processor, a radio frequency (RF) circuit, a
power amplifier, and the like. The wireless communication interface 913 may be a
25 single-chip module on which a memory for storing a communication control program,
a processor for executing the program, and a relevant circuit are integrated. The
wireless communication interface 913 may support other types of wireless
communication schemes such as a short-range wireless communication scheme, a
close proximity wireless communication scheme, or a cellular communication
30 scheme, in addition to the wireless LAN scheme. The antem1a switch 914 switches
a connection destination of the antenna 915 among a plurality of circuits (e.g.,
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circuits for different wireless communication schemes) included in the wireless
communication interface 913. The antenna 915 has a single antenna element or a
plurality of antenna elements (e.g., a plurality of antenna elements constituting a
MIMO antenna), and is nsed for transmission and reception of a wireless signal
5 through the wireless communication interface 913.
[0098]
Moreover, the configuration of the smartphone 900 is not limited to the
example of FIG. 16, and may include a plurality of antennas (e.g., an antenna for a
wireless LAN and an antenna for a proximity wireless communication scheme). In
' 10 this case, the antenna switch 914 may be omitted from the configuration of the
smartphone 900.
[0099]
The bus 917 connects the processor 901, the memory 902, the storage 903,
the externally connected interface 904, the camera 906, the sensor 907, the
15 microphone 908, the input device 909, the display device 910, the speaker 911, the
wireless communication interfuce 913, and the auxiliary controller 919 to one
another. The battery 918 supplies electric power to each of the blocks of the
smartphone 900 illustrated in FIG. 16 via a power supply line partially indicated by
dashed lines in the figure. The auxiliary controller 919 operates the required
20 minimum functions of the smartphone 900, in one example, in the sleep mode.
IOlOO]
In the smartphone 900 illustrated in FIG. !6, the wireless signal transmission
processing unit 205, the access control unit 208, and the wireless signal reception
processing unit 211 described with reference to FIG. 2 may be implemented in a
25 wireless communication interface 913. Also, at least some of the wireless signal
transmission processing unit 205, the access control unit 208, and the wireless signal
reception processing unit 211 may be implemented in a processor 901 or an auxiliary
controller 919. For example, the wireless signal transmission processing unit 205
converts a baseband signal into a high-frequency signal. The access control unit
30 208 controls access of communication on the wireless transmission path according to
a predetermined wireless communication protocol. Further, the wireless signal
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reception processing unit 211 extracts the baseband signal from the high-frequency
signal.
[0101)
Moreover, the smartphone 900 may operate as a wireless access point
5 (software AP) by the processor 901 executing an access point function at the
application level. In addition, the wireless communication interface 913 may have
the wireless access point function.
10
[0102)
[5-2. Second application example]
FIG. 17 is a block diagram illustrating an example of a schematic
configuration of a car navigation device 920 to which the technology according to
the present disclosure can be applied. The car navigation device 920 is configured
to include a processor 921, a memory 922, a global positioning system (GPS) module
924, a sensor 925, a data interface 926, a content player 927, a storage medium
15 interface 928, an input device 929, a display device 930, a speaker 931, a wireless
communication interface 933, an antenna switch 934, an antenna 935, and a battery
938.
[0103)
The processor 921 may be, in one example, a CPU or SoC, and controls a
20 navigation function and other functions of the car navigation device 920. The
memory 922 includes a RAM and a ROM, and stores programs executed by the
processor 921 and data.
[01 04)
The GPS module 924 measures the position (e.g., latitude, longitude, and
25 altitude) of the car navigation device 920 using GPS signals received from a GPS
satellite. The sensor 925 can include a sensor group including, in one example, a
gyro sensor, a geomagnetic sensor, and a barometric pressure sensor. The data
interface 926 is connected to, in one example, an in-vehicle network 941 via a
terminal that is not illustrated, and acquires data generated on the vehicle side such as
30 car speed data.
[0105)
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The content player 927 reproduces the content stored in a storage medium
(e.g., CD or DVD) inserted into the storage medium interface 928. The input
device 929 includes, in one example, a touch sensor that detects touches on a screen
of the display device 930, buttons, switches, and the like, and accepts an operation or
5 information input from the user. The display device 930 has a screen such as an
LCD or an OLED display, and displays a navigation function or an image of content.
The speaker 931 outputs sound of the navigation function or the content to he
reproduced.
[0106]
10 The wireless communication interface 933 supports one or more wireless
LAN standards such as IEEE 802.lla, llb, llg, lin, llac, and !lad, and executes
wireless LAN communication. The wireless communication interface 933 can
communicate with other devices via a wireless LAN access point in the infrastructure
mode. In addition, the wireless communication interface 933 can directly
15 communicate with other devices in a direct communication mode, such as an ad hoc
mode and Wi-Fi Direct. The wireless communication interface 933 can typically
have a baseband processor, an RF circuit, a power amplifier, and the like. The
wireless communication interface 933 may be a single-chip module on which a
memory for storing a communication control program, a processor for executing the
20 program, and a relevant circuit are integrated. The wireless communication
interface 933 may support other types of wireless communication schemes such as a
short-range wireless communication scheme, a close proximity wireless
communication scheme, or a cellular communication scheme, in addition to the
wireless LAN scheme. The antenna switch 934 switches a connection destination
25 of the antenna 935 among a plurality of circuits included in the wireless
communication interface 933. The antenna 935 has a single antenna element or a
plurality of antenna clements, and is used for transmission and reception of a
wireless signal from the wireless communication interface 933.
[0107]
30 Moreover, the configuration of the car navigation device 920 is not limited
to the example of FIG. 17, and may include a plurality of antennas. In this case, the
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antenna switch 934 may be omitted from the configuration of the car navigation
device 920.
[0108]
The battery 938 supplies electric power to each of the blocks of the car
5 navigation device 920 illustrated in FIG. 17 via a power supply line partially
indicated by a dashed line in the figure. In addition, the battery 938 accumulates
electric power supplied from the vehicle side.
[0109]
In the car navigation device 920 illustrated in FIG. 17, the wireless signal
10 transmission processing unit 205, the access control unit 208, and the wireless signal
reception processing unit 211 described with reference to FIG. 2 may be
implemented in a wireless communication interface 933. Also, at least some of the
wireless signal transmission processing unit 205, the access control unit 208, and the
wireless signal reception processing unit 211 may be implemented in a processor 921.
15 For example, the wireless signal transmission processing unit 205 converts a
baseband signal into a high-frequency signal. The access control unit 208 controls
access of communication on the wireless transmission path according to a
predetermined wireless communication protocol. Further, the wireless signal
reception processing unit 211 extracts the baseband signal from the high-frequency
20 signal.
[0110]
Further, the wireless communication interface 933 may operate as the
above-described communication control device and may provide wireless connection
to a terminal carried by a user who rides in a vehicle.
25 [Olll]
Further, the technology according to the present disclosure may be
implemented as an in-vehicle system (or vehicle) 940 including one or more blocks
of the above-described car navigation device 920, the in-vehicle network 941, and a
vehicle-side module 942. The vehicle-side module 942 generates vehicle-side data
30 such as vehicle speed, engine rpm, or failure information, and outputs the generated
data to the in-vehicle network 941.
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[0112]
[5-3. Third application example]
FIG 18 is a block diagram illustrating an example of a schematic
configuration of a wireless access point 950 to which the technology according to the
5 present disclosure can be applied. The wireless access point 950 is configured to
include a controller 951, a memory 952, an input device 954, a display device 955, a
network interface 957, a wireless communication interface 963, an antenna switch
964, and an antenna 965.
10
[0113]
The controller 951 may be, in one example, a CPU or a digital signal
processor (DSP), and operates various functions (e.g., access restriction, routing,
encryption, firewall, and log management) of the Internet Protocol (!P) layer and
higher layers of the wireless access point 950. The memory 952 includes a RAM
and a ROM, and stores a program to be executed by the controller 951 and various
Hi kinds of control dam (e.g., a terminal list, a routing table, an encryption key, security
settings, and a log).
[0 114]
The input device 954 includes, in one example, a button or a switch, and
accepts an operation from a user. The display device 955 includes an LED lamp or
20 the like, and displays operation status ofthe wireless access point 950.
[0115]
The network interface 957 is a wired communication interface that connects
the wireless access point 950 to the wired communication network 958. The
network interface 957 may include a plurality of connection terminals. The wired
25 communication network 958 may be a LAN such as Ethernet (registered trademark)
or a wide area network (WAN).
[0116]
The wireless communication interface 963 supports one or more wireless
LAN standards such as IEEE 802.lla, llb, llg, lin, llac, and !lad, and provides
30 wireless connection to a neighboring tenninal by functioning as an access point.
The wireless communication interface 963 can typically have a baseband processor,
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an RF circuit, a power amplifier, and the like. The wireless communication
interface 963 may be a single-chip module on which a memory for storing a
communication control program, a processor for executing the program, and a
relevant circuit are integrated. The antenna switch 964 switches a connection
5 destination of the antenna 965 among a plurality of circuits included in the wireless
communication interface 963. The antenna. 965 has a single antenna element or a
plurality of antenna elements, and is used for transmission and reception of a
wireless signal from the wireless communication interface 963.
10
[0117]
In the wireless access point 950 illustrated in FIG. I 8, the wireless signal
transmission processing unit 205, the access control unit 208, and the wireless signal
reception processing unit 211 described with reference to FIG. 2 may be
implemented in a wireless communication interface 963. Also, at least some of the
wireless signal transmission processing unit 205, the access control unit 208, and the
15 wireless signal reception processing unit 211 may be implemented in a controller 951.
For example, the wireless signal transmission processing unit 205 converts a
baseband signal into a high-frequency signaL The access control unit 208 controls
access of communication on the wireless transmission path according to a
predetermined wireless communication protocoL Further, the wireless signal
20 reception processing unit 211 extracts the baseband signal from the high-frequency
signaL
[0118]
<6. Conclusion>
As described above, according to the embodiments of the present disclosure,
25 there is provided a transmission control device that includes a communication control
unit that controls transmission of a plurality of pieces of data including respective
sequence numbers, and a data generation unit that generates, as information
indicating one or a plurality of pieces of data to be processed in a reception device
among the plurality of pieces of data, number information indicating the sequence
30 numbers included in the one or plurality of pieces of data to be processed, in which
the communication control unit controls transmission of the number information to
the reception device.
[0119]
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SP363752WOOO
According to the configuration, even when a sequence number space is
shared among the plurality of pieces of multicast data transmitted from the
5 transmission-side communication device, predetermined processmg can be
perfonned on desired data in the reception-side communication device.
[0 120]
Further, by usmg flush information, when a sequence number of a
transmission-side communication device is shared for multicast communication, data
10 received by a reception-side communication device may be flushed from a buffer.
The transmission-side communication device may transmit a flush frame for each
multicast flow and manage a single sequence number space for multicast
communication of a plurality of other flows. Also, the reception-side
communication device can simplify a management method of a sequence number of
15 desired multicast communication, which is designated as destination itself.
[0121]
The reception-side communication device can easily separate pieces of data
sent using the same sequence number in the data frame and the management frame.
Also, even when the reception-side communication device receives flush information
20 which is not required by itself, the reception-side communication device can easily
grasp the latest sequence numbers thereof By defining a flush frame in which flush
information is defined, when the reception-side communication device receives a
flush frame of a flow designated as a destination itself, the reception-side
communication device can flush received data from a buffer without waiting for a
25 predetermined timeout time.
[0122]
30
By defining a flush information element for a beacon signal, the receptionside
communication device can flush a multicast frame to be collected by itself even
when the reception-side communication device receives a multicast frame used in
another adjacent network. Further, by storing flush information as header
information of a data frame, the flush information can be sent to the reception-side
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communication device without sending another frame.
[0123]
SP363752WOOO
The preferred embodiments of the present disclosure have been described
above with reference to the accompanying drawings, whilst the present disclosure is
5 not limited to the above examples. A person skilled in the art may find various
alterations and modifications within the scope of the appended claims, and it should
be understood that they will naturally come under the technical scope of the present
disclosure.
10
[0124]
Although a process using the block ACK has been described above as an
example, embodiments of the present disclosure are not limited thereto and can be
applied to any delivery confirmation processing.
[0125]
Further, a program for causing hardware, such as a CPU, ROM and RAM
15 built into a computer, to exhibit functions similar to the functions included in the
above described the communication device I 0 can be created. Further, a recording
medium can also be provided which records these programs and is capable of
performing reading to the computer.
[0126]
20 Further, the effects described in this specification are merely illustrative or
25
exemplified effects, and are not limitative. That is, with or in the place of the above
effects, the technology according to the present disclosure may achieve other effects
that are clear to those skilled in the art from the description of this specification.
[0 127]
Additionally, the present technology may also be configured as below.
(1)
A transmission control device including:
a communication control unit that controls transmission of a plurality of
pieces of data including respective sequence numbers; and
30 a data generation unit that generates, as information indicating one or a
plurality of pieces of data to be processed in a reception device among the plurality
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of pieces of data, number information indicating the sequence numbers included in
the one or plurality of pieces of data to be processed,
in which the communication control unit controls transmission of the
number information to the reception device.
5 (2)
10
The transmission control device according to (l ), in which the
communication control unit controls transmission of the number information by
multicast communication.
(3)
The transmission control device according to (2), in which the number
information is defined for each flow of the multicast communication.
(4)
The transmission control device according to any one of (1) to (3), in which
the communication control unit controls transmission of a management frame
15 including the number information to the reception device.
(5)
The transmission control device according to any one of (1) to (3 ), in which
the communication control unit controls transmission of a beacon signal including
the number information to the reception device.
20 (6)
25
The transmission control device according to any one of (1) to (3), in which
the communication control unit controls transmission of a data frame for which the
number information is set in header information to the reception device.
(7)
A transmission control method including:
controlling transmission of a plurality of pieces of data including respective
sequence numbers;
generating, as information indicating one or a plurality of pieces of data to
be processed in a reception device among the plurality of pieces of data, number
30 infmmation indicating the sequence numbers included in the one or plurality of
pieces of data to be processed; and
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controlling transmission ofthe number information to the reception device.
(8)
A reception control device including:
a communication control unit that controls reception, from a transmission
5 device, of number information indicating sequence numbers included in one or a
plurality of pieces of data to be processed, as information indicating the one or
plurality of pieces of data to be processed among a plurality of pieces of data
including respective sequence numbers; and
a data acquisition unit that acquires the number information.
10 (9)
The reception control device according to (8), including:
a storage control unit that flushes the one or plurality of pieces of data to be
processed from a storage area in a case in which it is determined that the one or
plurality of pieces of data to be processed are received with reference to the number
15 information.
(10)
The reception control device according to (9), in which, in a case in which
number information for each flow is received, the storage control unit refers to the
number information for each of the flows and, in a case in which it is determined that
20 one or plurality of pieces of data to be processed related to all of the flows are
received, flushes the one or plurality of pieces of data to be processed related to all of
the flows from the storage area.
(II)
The reception control device according to (9), in which, in a case in which
25 number information for each flow is received, the storage control unit refers to the
number information for each of the flows and, in a case in which it is determined that
one or plurality of pieces of data to be processed related to some of the flows are
received, flushes the one or plurality of pieces of data to be processed related to some
of the flows from the storage area and does not flush the one or plurality of pieces of
30 data to be processed related to the rest ofthe flows.
(12)
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The reception control device according to (8), including:
a storage control unit that delivers the one or plurality of pieces of data to be
processed from a storage area to an upper layer in a case in which it is determined
that the one or plurality of pieces of data to be processed are received with reference
5 to the number information.
(13)
The reception control device according to (8), including:
a storage control unit that flushes received data to be processed from a
storage area in a case in which it is determined that reception of the one or plurality
10 of pieces of data to be processed is not completed even after a lapse of a
predetermined period with reference to the number information.
(14)
A reception control method including:
controlling reception, from a transmission device, of number information
15 indicating sequence numbers included in one or a plurality of pieces of data to be
processed, as information indicating the one or plurality of pieces of data to be
processed among a plurality of pieces of data including respective sequence
numbers; and
acquiring the number information.
20
Reference Signs List
[0128]
1 communication system
10
25 201
communication device
interface unit
202 transmitting buffer unit
203 Buffer management unit
204 transmission data frame construction unit 204
205 wireless signal transmission processing unit
30 206
207
multicast transmission sequence management unit 206
flush frame construction unit
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208 access control nnit
209 antenna control unit
210 antenna element
211 wireless signal reception processing unit
5 212 reception data frame extraction unit
213 receiving buffer unit
214 flush frame extraction unit
215 multicast reception sequence management unit
SP363752WOOO

CLAIMS
Claim I
A transmission control device comprising:
a communication control unit that controls transmission of a plurality of
5 pieces of data including respective sequence numbers; and
10
a data generation unit that generates, as information indicating one or a
plurality of pieces of data to be processed in a reception device among the plurality
of pieces of data, number information indicating the sequence numbers included in
the one or plurality of pieces of data to be processed,
wherein the communication control unit controls transmission of the number
information to the reception device.
Claim 2
The transmission control device according to claim 1, wherein the
15 communication control unit controls transmission of the number information by
multicast communication.
Claim 3
The transmission control device according to claim 2, wherein the number
20 information is defined for each flow of the multicast communication.
Claim 4
The transmission control device according to claim 1, wherein the
communication control unit controls transmission of a management frame including
25 the number information to the reception device.
Claim 5
The transmission control device according to claim 1, wherein the
communication control unit controls transmission of a beacon signal including the
30 number information to the reception device.
5
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Claim 6
The transmission control device according to claim I, wherein the
communication control unit controls transmission of a data frame for which the
number information is set in header information to the reception device.
Claim 7
A transmission control method comprising:
controlling transmission of a plurality of pieces of data including respective
sequence numbers;
10 generating, as information indicating one or a plurality of pieces of data to
15
be processed in a reception device among the plurality of pieces of data, number
information indicating the sequence numbers included in the one or plurality of
pieces of data to be processed; and
controlling transmission of the number information to the reception device.
Claim 8
A reception control device comprising:
a communication control unit that controls reception, from a transmission
device, of number information indicating sequence numbers included in one or a
20 plurality of pieces of data to be processed, as information indicating the one or
plurality of pieces of data to be processed among a plurality of pieces of data
including respective sequence numbers; and
a data acquisition unit that acquires the number information.
25 Claim 9
The reception control device according to claim 8, comprising:
a storage control unit that flushes the one or plurality of pieces of data to be
processed from a storage area in a case in which it is determined that the one or
plurality of pieces of data to be processed are received with reference to the number
30 information.
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Claim 10
The reception control device according to claim 9, wherein, in a case in
which number information for each flow is received, the storage control unit refers to
the number information for each of the flows and, in a case in which it is determined
5 that one or plurality of pieces of data to be processed related to all of the flows are
received, flushes the one or plurality of pieces of data to be processed related to all of
the flows from the storage area.
Claim I J
10 The reception control device according to claim 9, wherein, in a case in
which number information for each flow is received, the storage control unit refers to
the number information for each of the flows and, in a case in which it is determined
that one or plurality of pieces of data to be processed related to some of the flows are
received, flushes the one or plurality of pieces of data to be processed related to some
15 of the flows from the storage area and does not flush the one or plurality of pieces of
data to be processed related to the rest of the flows.
20
Claim 12
The reception control device according to claim 8, comprising:
a storage control unit that delivers the one or plurality of pieces of data to be
processed from a storage area to an upper layer in a case in which it is detennined
that the one or plurality of pieces of data to be processed are received with reference
to the number information.
25 Claim 13
The reception control device according to claim 8, comprising:
a storage control unit that flushes received data to be processed from a
storage area in a case in which it is determined that reception of the one or plurality
of pieces of data to be processed is not completed even after a lapse of a
30 predete1mined period with reference to the number information.
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Claim 14
A reception control method comprising:
controlling reception, from a transmission device, of number infonnation
indicating sequence numbers included in one or a plurality of pieces of data to be
5 processed, as information indicating the one or plurality of pieces of data to be
processed among a plurality of pieces of data including respective sequence
numbers; and