Title of Invention
RADIO COMMUNICATION DEVICE, RADIO COMMUNICATION METHOD AND
[0001]
RADIO COMMUNICATION SYSTEM
Technical Field
The present invention relates to a radio communication device, a radio
10 communication method and a radio communication system.
Background Art
[0002]
For radio communication, wireless local area network (LAN) standards such as
15 IEEE802.11 have been set. As the wireless LAN standards, higher standards that
support higher communication rates using the same frequency band tend to be set in
sequence. For example, a higher standard than IEEE802.11a, IEEE802.1 tn, has
already been set.
[0003]
20 In the case of radio communication including communication conforming to a
wireless LAN standard as mentioned above, it is necessary to avoid collisions of
communication in the same frequency band. To this end, for example, in IEEE802.1 I,
a Request To Send/Clear To Send (RTS/CTS) mechanism has been introduced. In this
mechanism, a radio communication device that will perform data transmission performs
25 communication for ensuring communication time with another nearby radio
communication device before data transmission.
[0004]
When a higher standard and a lower standard such as IEEE802.11 a and
IEEE802.1in are permitted to coexist in the same frequency band, for example,
30 communication for the RTS/CTS needs to be performed according to the lower standard
so that a radio communication device corresponding only to the lower standard can also
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receive the RTS/CTS. Asa result, even during transmission and reception according to
the higher standard, .low-speed communication is performed according to the lower
standard and overhead of the higher standard increases, and thus full performance may
not be exhibited.
5 [0005]
In Patent Literature I below, an example of technology for avoiding a
communication collision without using a sequence such as the RTS/CTS in an
environment in which two communication schemes of higher and lower standards
coexist is disclosed.
10 [0006]
For example, in wireless LAN standards, a standard that is referred to as
IEEE802. i i ac and supports a further higher communication rate has recently been set
above IEEE802.lla and IEEE802.11n. In this way, coexistence of three
communication schemes constituting classes in radio communication is being realized.
15
Citation List
[Patent Literature]
[0007]
Patent Literature 1: JP 2006-50526A
20
Summary of Invention
Technical Problem
[0008]
- However, when three communication schemes constituting classes in radio
25 communication coexist, a method such as the Request To Send/Clear To Send
(RTS/CTS) further increases overhead of an upper standard , and it is impossible to
exhibit full performance.
[0009]
The present invention has been achieved in consideration of these problems, and
30 is intended to provide an improved new radio communication device, radio
communication method and radio communication system capable of enabling
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coexistence of the three communication schemes constituting the classes while
suppressing overhead.
Solution to Problem
5 [0010]
According to an aspect of the present invention in order to achieve the
above-mentioned object, there is provided a radio communication device including: a
packet generation unit for generating a packet including first decoding information that
can be recognized by a radio communication device corresponding to a first
10 communication scheme, second decoding information that can be recognized by a radio
communication device corresponding to a second communication scheme and third
decoding information that can be recognized by a radio communication device
corresponding to a third communication scheme; and a transmission unit for transmitting
the packet generated by the packet generation unit.
15 [0011]
This configuration allows decoding information that can be recognized by
respective communication schemes to be included in one packet, and it is possible to
enable the three communication schemes constituting classes to coexist while
suppressing overhead.
20 [0012]
The radio communication device corresponding to the first communication
scheme may correspond only to the first communication scheme, the radio
communication device corresponding to the second communication scheme may also
correspond to the first communication scheme, and the radio communication device
25 corresponding to the third communication scheme may also correspond to the first
communication scheme and the second communication scheme.
[0013]
The packet may include the second decoding information following the first
decoding information, and the third decoding information following the second decoding
30 information.
[0014]
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The first decoding information may include information for calculating a first
duration in which the radio communication device corresponding only to the first
communication scheme is caused to keep performing a receiving operation, and the
second decoding information may include information for calculating a second duration
5 in which the radio communication device that corresponds to the second communication
scheme but does not correspond to the third communication scheme is caused to keep
performing a receiving operation.
[0015]
The first duration and the second duration may end at different times.
10 [0016]
The first decoding information may include first continuation information
indicating presence of the second decoding information to the radio communication
device corresponding to the second communication scheme and the radio
communication device corresponding to the third communication scheme, and the
15 second decoding information may include second continuation information indicating
presence of the third decoding information to the radio communication device
corresponding to the third communication scheme.
[0017]
When the radio communication device corresponding only to the first
20 communication scheme is not within a range in which the packet is transmitted, the
packet generation unit may generate the packet without the first decoding information.
[0018]
When the radio communication device that corresponds to the second
communication scheme but does not correspond to the third communication scheme is
25 not within a range in which the packet is transmitted, the packet generation unit may
generate the packet without the second decoding information.
[0019]
According to another aspect of the present invention in order to achieve the
above-mentioned object, there is provided a radio communication device including: a
30 reception unit for receiving a packet including first decoding information that can be
recognized by a radio communication device corresponding to a first communication
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scheme, second decoding information that can be recognized by a radio communication
device corresponding to a second communication scheme and third decoding
information that can be recognized by a radio communication device corresponding to a
third communication scheme; and a packet analysis unit for analyzing the packet
5 received by the reception unit.
[0020]
The packet may include the second decoding information following the first
decoding information, and the third decoding information following the second decoding
information.
1o [0021]
The first decoding information may include first continuation information
indicating presence of the second decoding information to the radio communication
device corresponding to the second communication scheme and the radio
communication device corresponding to the third communication scheme, and the
15 second decoding information may include second continuation information indicating
presence of the third decoding information to the radio communication device
corresponding to the third communication scheme.
[0022]
The reception unit may keep perfonning a receiving operation on the basis of
20 information included in the third decoding information according to the first
communication scheme, the second communication scheme and the third
communication scheme.
[0023]
According to still another aspect of the present invention in order to achieve the
25 above-mentioned object, there is provided a radio communication method including the
steps of. generating a packet including first decoding information that can be recognized
by a radio communication device corresponding to a first communication scheme,
second decoding information that can be recognized by a radio communication device
corresponding to a second communication scheme and third decoding information that
30 can be recognized by a radio communication device corresponding to a third
Communication scheme; and transmitting the packet generated in the generating step.
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[0024]
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According to yet another aspect of the present invention in order to achieve the
above-mentioned object, there is provided a radio communication method including the
steps of. receiving a packet including first decoding information that can be recognized
5 by a radio communication device corresponding to a first communication scheme,
second decoding information that can be recognized by a radio communication device
corresponding toa second communication scheme and third decoding information that
can be recognized by a radio communication device corresponding to a third
communication scheme; and analyzing the packet received in the receiving step.
10 [0025]
According to yet another aspect of the present invention in order to achieve the
above-mentioned object, there is provided a radio communication system including: a
first radio communication device having a packet generation unit for generating a packet
including first decoding information that can be recognized by a radio communication
15 device corresponding to a first communication scheme, second decoding information
that can be recognized by a radio communication device corresponding to a second
communication scheme and third decoding infonnation that can be recognized by a
radio communication device corresponding to a third communication scheme, and a
transmission unit for transmitting the packet generated by the packet generation unit;
20 and a second radio communication device having a reception unit for receiving the
packet, and a packet analysis unit for analyzing the packet received by the reception
unit.
Advantageous Effects of Invention
25 [0026]
According to the above-described present invention, it is possible to permit
three communication schemes constituting classes to coexist while suppressing
overhead.
30 Brief Description of Drawings
[0027]
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[Fig. 1] Fig. I is a diagram showing an example of a radio communication system
according to an embodiment of the present invention.
[Fig. 2] Fig. 2 is a diagram illustrating an example of communication when a Request To
Send/Clear To Send (RTS/CTS) mechanism is used in the radio communication system
5 of Fig. 1.
[Fig. 3] Fig. 3 is a diagram showing a configuration of a radio communication device
according to an embodiment of the present invention.
[Fig. 4] Fig. 4 is a diagram showing an example of a frame configuration of a packet
relating to a first embodiment of the present invention.
10 [Fig. 5] Fig. 5 is a diagram illustrating operation of each radio communication device
receiving a packet in a radio communication system relating to the same embodiment.
[Fig. 6] Fig. 6 is a diagram illustrating an example of a relationship between durations
relating to a modified example of the same embodiment.
[Fig. 7] Fig. 7 is a diagram showing an example of a frame configuration of a packet
15 relating to a second embodiment of the present invention.
[Fig. 8] Fig. 8 is a diagram showing in detail a frame configuration of a packet relating
to the same embodiment.
[Fig. 9] Fig. 9 is a diagram showing an example of a frame configuration of a packet
relating to a third embodiment of the present invention.
20 [Fig. 10] Fig. 10 is a flowchart illustrating operation during data transmission of a radio
communication device relating to a fourth embodiment of the present invention.
[Fig. 11] Fig. 11 is a flowchart illustrating operation during data reception of the radio
communication device relating to the same embodiment.
25 Description of Embodiments
[0028]
Hereinafter, preferred embodiments of the present invention will be described in
detail with reference to the appended drawings. Note that, in this specification and the
drawings, elements that have substantially the same function and structure are denoted
30 with the same reference signs, and repeated explanation is omitted.
[0029]
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In this specification and the drawings, a plurality of elements having
substantially the same functional configuration may be distinguished according to
different alphabetic characters added after the same sign. For example, a plurality of
elements having substantially same the functional configuration may be distinguished as
5 radio communication devices 100A and I OOB according to necessity. However, when
there is no particular need to distinguish a plurality of elements having substantially the
same functional configuration, only the common symbol is given. For example, when
there is no particular need to distinguish the radio communication devices 100A and
100B, they are simply referred to as radio communication devices 100.
to [0030]
A description will be given in the following order.
1. Radio Communication System According to Embodiment of Present
Invention
2. Radio Communication Device According to Embodiment of Present
15 Invention
3. Embodiments of Present Invention
3-1. First Embodiment
3-1-1. Configuration of Packet
3-1-2. Operation of Radio Communication Device Performing Transmission
20 and Reception
3-1-3. Operation of Other Radio Communication Devices
3-1-4. Effect of Present Embodiment
3-1-5. Modified Example
3-2. Second Embodiment
25 3-2-1. Configuration of Packet
3-2-2. Example of Operation of Radio Communication Device
3-2-3. Effect of Present Embodiment
3-3. Third Embodiment
3-3-1. Configuration of Packet
30 3-3-2. Case to Which Present Embodiment Can Be Applied
3-3-3. Effect of Present Embodiment
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3-4. Fourth Embodiment
3-4-1. Operation of Radio Communication Device During Data Transmission
3-4-2. Operation of Radio Communication Device During Data Reception
4. Additions
5 [0031]
<1.
Invention>
Radio Communication System According to Embodiment of Present
Fig. I is a diagram showing an example of a radio communication system
according to an embodiment of the present invention. A radio communication system
10 1 includes radio communication devices 10A, 10B, 20A, 20B, 100A and 100B. The
radio communication devices are each, for example, a personal computer (PC), a home
image processing device (DVD recorder, video deck, or the like), a personal digital
assistant (PDA), a home game machine, an electric appliance, a portable image
processing device, a portable game machine, and the like. In the radio communication
15 system 1, communication is performed by such radio communication devices.
[0032]
In the radio communication system 1, three communication schemes including a
first communication scheme, a second communication scheme and a third
communication scheme coexist in the same frequency band. The radio communication
20 devices 10A and 10B correspond to the first communication scheme, the radio
communication devices 20A and 20B correspond to the second communication scheme,
and the radio communication devices 100A and 100B correspond to the third
communication scheme.
[0033]-
25 Here, the first communication scheme, the second communication scheme and
the third communication scheme are three communication schemes constituting classes.
In other words, the second communication scheme is a higher standard than the first
communication scheme, and the third communication scheme is a higher standard than
the second communication scheme.
30 [0034]
In the radio communication system 1, the radio communication devices
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corresponding to the respective communication schemes have compatibility with
communication schemes corresponding to lower standards. In other words, the radio
communication devices IOA and I OB corresponding to the first communication scheme
correspond only to the first communication scheme, the radio communication devices
5 20A and 20B corresponding to the second communication scheme also correspond to the
first communication scheme, and the radio communication devices IOOA and IOOB
corresponding to the third communication scheme also correspond to the first
communication scheme and the second communication scheme.
[0035]
10 Fig. 2 is a diagram illustrating an example of communication when a Request
To Send/Clear To Send (RTS/CTS) mechanism is used to transmit data from the radio
communication device lOOA to the radio communication device 100B in the radio
communication system 1 as described above. In addition to the radio communication
device I OOA that is a transmission source and the radio communication device I OOB that
15 is a transmission destination, the radio communication device IOA is shown as a radio
communication device in the radio communication system 1.
[0036]
The radio communication device I00A first transmits an RTS 31 that requests
transmission of data. The RTS 31 is received by the radio communication device 100E
20 that is a transmission destination and the other radio communication device I OA.
[0037]
The radio communication device 100B transmits a CTS 33 indicating that
preparation for data reception has been completed as a response to the RTS 31. The
radio communication device lOOA having received the CTS 33 transmits data 35. The
25 radio communication device 100B that has finished receiving the data 35 transmits an
ACID 37 indicating that reception has been completed normally.
[0038]
Meanwhile, when the RTS 31 is received, the radio communication device I OA
sets a network allocation vector (NAV) 39. The NAV 39 is a transmission suppression
30 period for preventing a communication collision occurring when another radio
communication device transmits data while the radio communication device 100A and
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the radio communication device 100B are performing data transmission and reception.
[0039]
The radio communication device IOA having set the NAV 39 is controlled not
to start data transmission for a predetermined time designated by the RTS 31, for
5 example, a time until the ACK 37 is transmitted after the RTS 31 is received.
[0040]
As mentioned above, the radio communication device 10A corresponds to the
first communication scheme. Accordingly, the radio communication device 100A
needs to transmit the RTS 31 using the first communication scheme that the radio
10 communication device l0A can recognize. This is because, when the radio
communication device IOA is not able to recognize the RTS 31, the radio
communication device 10A is not able to set the NAV 39 and may cause a
communication collision by, for example, starting transmission of other data during
transmission of the data 35.
15 [0041]
Transmission and reception of the data 35 between the radio communication
device IOOA and the radio communication device 100B corresponding to the third
communication scheme can be performed using a high-speed transmission rate used in
the third communication scheme. However, transmission and reception of the RTS 31
20 and the like should be performed using a low-speed transmission rate used in the first
communication scheme. Accordingly, overhead due to transmission and reception of
the RTS 31 becomes relatively large, and performance of the third communication
scheme is not able to be fully exhibited.
[0042]-
25 In the radio communication system 1 according to the embodiment of the
present invention, the three communication schemes constituting the classes coexist as
described above.
[0043]
<2. Radio Communication Device According to Embodiment of Present
30 Invention >
Fig. 3 is a diagram showing a configuration of a radio communication device
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100 according to an embodiment of the present invention. The radio communication
device 100 has an interface 151, a. data buffer 153, a packet generation unit 155, a
transmission unit 157, an antenna 159, a reception unit 161, a packet analysis unit 163, a
control unit 165 and a storage unit 167.
5 [0044]
The interface 151 performs input and output of data transmitted and received
between an external communication device and the radio communication device 100 via,
for example, a network. The data buffer 153 temporarily stores transmission data input
to the interface 151 or reception data to be output from the interface 151.
to [0045]
The packet generation unit 155 generates a packet transmitted by the radio
communication device 100. For example, when data is transmitted, the packet
generation unit 155 generates a packet by adding a control header to data stored in the
data buffer 153. In the control header, decoding information for decoding the data is
15 included.
[0046]
The transmission unit 157 transmits the packet generated by the packet
generation unit 155 to another radio communication device of the radio communication
system I through the antenna 159. When the communication scheme corresponding to
20 the radio communication devices 100 supports multi-input multi-output (MIMO), the
antenna 159 may consist of a plurality of antennas.
[0047]
The reception unit 161 receives a packet from another radio communication
device--of the radio communication system I through the antenna 159. The packet
25 analysis unit 163 analyzes the packet received by the reception unit 161. For example,
when data is received, the packet analysis unit 163 decodes the data on the basis of
decoding information obtained by analyzing a control header included in the packet, and
stores the decoded data in the data buffer 153.
[0048]
30 The control unit 165 controls operation of the packet generation unit 155, the
transmission unit 157, the reception unit 161 and the packet analysis unit 163. The
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storage unit 167 stores information necessary for the control unit 165 to perform a
process.
[0049]
Each function of the radio communication devices 100 may be implemented as
5 dedicated hardware or implemented as software using a computer. In this case, the
computer properly has a central processing unit (CPU), storage devices such as a hard
disk drive (HDD), a read only memory (ROM) and a random access memory (RAM), a
communication device connected to networks such as LAN and the Internet, input
devices such as a mouse and a keyboard, and a drive for reading from and writing to a
10 removable storage medium such as a magnetic disk, an optical disc or a semiconductor
memory. Each function of the radio communication devices 100 may be implemented
when the CPU executes a program stored in the storage devices or the removable storage
medium or a program obtained via a network.
[0050]
15 <3. Embodiment of Present Invention>
[3-1. First Embodiment]
(3-1-1. Configuration of Packet)
Fig. 4 is a diagram showing an example of a frame configuration of a packet
200 relating to a first embodiment of the present invention. The packet 200 includes
20 first decoding information 201, second decoding information 202, third decoding
information 203, and data 210.
[0051]
The first decoding information 201 can be recognized by a radio communication
device-corresponding to the first communication scheme, and includes information of a
25 packet length or a transmission rate necessary to receive data. The second decoding
information 202 is included following the first decoding information 201, can be
recognized by a radio communication device corresponding to the second
communication scheme, and includes information of a packet length or a transmission
rate necessary to receive data.
30 [0052]
The third decoding information 203 is included following the second decoding
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information 202, can be recognized by a radio communication device corresponding to
the third communication scheme, and includes information of a packet length or a
transmission rate necessary to receive data. The data 210 can be recognized by a radio
communication device corresponding to the third communication scheme, and is
5 transmitted using the packet length and the transmission rate included in the third
decoding information 203.
[0053]
(3-1-2. Operation of Radio Communication Device Performing Transmission
and Reception)
10 When the radio communication device 100 performs data transmission, first, the
packet generation unit 155 adds the first decoding information 201, the second decoding
information 202 and the third decoding information 203 each as a control header to the
data 210 stored in the data buffer 153, thereby generating the packet 200.
[0054]
15 Next, the transmission unit 157 transmits the packet 200 through the antenna
159.
[0055]
Meanwhile, when the radio communication device 100 performs data reception,
first, the reception unit 161 receives the packet 200 through the antenna 159.
20 [0056]
Next, the packet analysis unit 163 analyzes a control header included in the
packet 200. In the control header, the first decoding information 201, the second
decoding information 202 and the third decoding information 203 is included. The
packet-analysis unit 163 decodes the data 210 on the basis of information obtained by
25 analyzing any piece of the decoding information, and stores the decoded data in the data
buffer 153.
[0057]
(3-1-3. Operation of Other Radio Communication Devices)
Fig. 5 is a diagram illustrating operation of each radio communication device
30 receiving the packet 200 transmitted by the radio communication device 100A in the
radio communication system 1 relating to the first embodiment of the present invention.
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As described above, the radio communication device I OA corresponds only to the first
communication scheme, the radio communication device 20A corresponds to the first
communication scheme and the second communication scheme, and the radio
communication device 100E corresponds to all of the first communication scheme, the
5 second communication scheme and the third communication scheme.
[0058]
The radio communication device 1OA can only recognize the first decoding
information 201 included in the packet 200. The radio communication device 10A is
not able to recognize the other portions of the packet 200 in accordance with the second
to communication scheme or the third communication scheme, but keeps performing a
reception operation during a first duration tI calculated from the packet length and the
transmission rate included in the first decoding information 201.
[0059]
The radio communication device 20A can recognize the first decoding
15 information 201 and the second decoding information 202 included in the packet 200.
The radio communication device 20A is not able to recognize the other portion of the
packet 200 in accordance with the third communication scheme, but keeps performing a
reception operation during a second duration t2 calculated from the packet length and
the transmission rate included in the second decoding information 202.
20 [0060]
The radio communication device 100E can recognize all the information
included in the packet 200. The radio communication device 100E keeps performing a
reception operation during a third duration t3 calculated from the packet length and the
transmission rate included in the third decoding information 203, and receives and
25 decodes the data 210 on the basis of the information included in the third decoding
information 203.
[0061]
Since a radio communication device does not start transmission while
performing a reception operation, the radio communication device IOA is controlled not
30 to start transmission during the first duration it, and the radio communication device
20A is controlled not to start transmission during the second duration Q. In other
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words, it is possible to obtain the same effect as in a case in which a NAV is set
according to a sequence of the RTS/CTS.
[0062]
(3-1-4. Effect of Present Embodiment)
5 In the above-described first embodiment of the present invention, when the
three communication schemes constituting the classes coexist, a radio communication
device that corresponds only to a lower communication scheme can be controlled not to
start data transmission during a predetermined time without using a sequence such as the
aforementioned RTS/CTS, and it is possible to suppress overhead when communication
10 is performed using an upper communication scheme.
[0063]
(3-1-5. Modified Example)
Fig. 6 is a diagram illustrating an example of a relationship between durations
calculated from packet lengths and transmission rates included in respective pieces of
15 decoding information. In this example, a second duration t2 is a time from when
transmission of data 210 is finished until an acknowledgement (ACK) of the data 210 is
sent. Meanwhile, a first duration tl extends beyond the time when the ACK is sent.
[0064]
In this way, by setting a time when the first duration tl ends and a time when
20 the second duration t2 ends to different times, it is possible to perform communication
during a time t4 from when the ACI{ is sent until the first duration tl cods on the
assumption that there is no radio communication device capable of decoding only first
decoding information, that is, no radio communication device corresponding only to the
first communication scheme.
25 [0065]
Using the. above-described configuration, for example, a time in which only a
radio communication device corresponding to a higher communication scheme can
communicate is ensured to perform communication without regard for the presence of a
radio communication device corresponding only to a lower communication scheme
30 during this time, and thus overhead can be further suppressed when communication is
performed using the higher communication scheme.
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[3-2. Second Embodiment]
(3-2-1. Configuration of Packet)
Fig. 7 is a diagram showing an example of a frame configuration of a packet
5 200 relating to a second embodiment of the present invention. In the present
embodiment, first decoding information 201 includes first continuation information 221.
Also, second decoding information 202 includes second continuation information 222.
[0067]
The first continuation information 221 is information indicating that the second
to decoding information 202 is following the first decoding information 201 to a radio
communication device corresponding to the second communication scheme and a radio
communication device corresponding to the third communication scheme.
[0068]
For example, a specific combination of values of a packet length and a
15 transmission rate included in the first decoding information 201 can be the first
continuation information 221. In this case, when the values of the packet length and
the transmission rate included in the first decoding information 201 are the specific
combination, the radio communication device corresponding to the second
communication scheme and the radio communication device corresponding to the third
20 communication scheme determine that the second decoding information 202 is
following the first decoding information 201.
[0069]
The second continuation information 222 is information indicating that third
decoding information 203 is following the second decoding information 202 to the radio
25 communication device corresponding to the third communication scheme.
[0070]
For example, a specific combination of values of a packet length and a
modulation scheme included in the second decoding information can be the second
continuation information 222. In this case, when the values of the packet length and
30 the modulation scheme included in the second decoding information 202 are the specific
combination, the radio communication device corresponding to the third communication
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scheme determines that the third decoding information 203 is following the second
decoding information 202.
[0071]
(3-2-2. Example of Operation of Radio Communication Device)
5 Fig. 8 is a diagram 'showing a packet configuration when the three
communication schemes respectively in accordance with IEEE802.11a, IEEE802.1in
and 1EEE802.1 lac of wireless LAN standards coexist, as a detailed example of a frame
configuration of the packet 200 relating to the second embodiment of the present
invention. An 802.11a physical (PHY) header corresponds to the first decoding
10 information 201, an 802.11n PHY header corresponds to the second decoding
information 202, and an 802.1lac PHY header corresponds to the third decoding
information 203.
[0072]
Operation of a case in which the radio communication device 100 relating to the
15 second embodiment of the present invention performs data transmission will be
described using the example. First, the control unit 165 causes the packet generation
unit 155 to generate an 802.1 la PHY header so that values ofa transmission rate and a
packet length (not shown) included in a legacy signal (L-SIG) portion can be a
predetermined specific combination.
20 [0073]
Next, the control unit 165 causes the packet generation unit 155 to generate an
802.1 In PITY header so that values of a modulation and coding scheme (MCS) and a
length (packet length) included in a high throughput signal (HT-SIG) portion can be a
predetermined specific combination.
25 [0074]
Furthermore, the control unit 165 causes the packet generation unit 155 to
generate an 802.11 ac PITY header with a value necessary for receiving actual data 210.
The packet generation unit 155 generates the packet 200 by adding the respective
generated PHY headers to the data 210 as shown in Fig. 8, and the transmission unit 157
30 transmits the packet 200 through the antenna 159.
[0075]
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Next, operation of a case in which the radio communication device 100 relating
to the second embodiment of the present invention performs data reception will be
described using the example. First, the control unit 165 determines whether values of a
transmission rate and a packet length included in an L-SIG portion of an 802.1 la PHY
5 header analyzed by the packet analysis unit 163 are a predetermined specific
combination. When the values of the transmission rate and the packet length are the
predetermined specific combination, the control unit 165 causes the packet analysis unit
163 to analyze an 802.11 In PHY header in succession.
[0076]
10 Next, the control unit 165 determines whether values of an MCS and a length
included in an HT-SIG portion of the 802.11n PHY header analyzed by the packet
analysis unit 163 are a predetermined specific combination. When the values of the
MCS and the length are the predetermined specific combination, the control unit 165
causes the packet analysis unit 163 to analyze an 802.1 lac PHY header in succession.
15 [0077]
Also, the control unit 165 causes the reception unit 161 to keep performing a
reception operation according to the content of the 802.1 lac PHY header analyzed by
the packet analysis unit 163, and causes the packet analysis unit 163 to decode the data
210. The packet analysis unit decodes the data according to the content of the 802.1lac
20 PHY header and stores the decoded data in the data buffer 153.
[0078]
(3-2-3. Effect of Present Embodiment)
In the above-described second embodiment of the present invention, when the
three communication schemes constituting the classes coexist, a radio communication
25 device that corresponds to a plurality of communication schemes can readily determine
whether or not there is decoding information of a communication scheme of a higher
class.
[0079]
[3-3. Third Embodiment]
30 (3-3-1. Configuration of Packet)
Fig. 9 is a diagram showing an example of a frame configuration of a packet
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200 relating to a third embodiment of the present invention. According to the present
embodiment, first decoding information 201 or second decoding information 202 is
omitted from the packet 200.
[0080]
5 When it is possible to perform communication on the assumption that no radio
communication device corresponding only to the first communication scheme is within a
range in which the packet 200 is transmitted by the transmission unit 157, the control
unit 165 of the radio communication unit 100 controls the packet generation unit 155 to
generate the packet 200 without the first decoding information 201.
10 [0081]
Also, when it is possible to perform communication on the assumption that no
radio communication device that corresponds to the second communication scheme but
does not correspond to the third communication scheme is within the range in which the
packet 200 is transmitted by the transmission unit 157, the control unit 165 controls the
15 packet generation unit 155 to generate the packet 200 without the second decoding
information 202.
[0082]
(3-3-2. Case to Which Present Embodiment Can Be Applied)
When the modified example of the first embodiment of the present invention
20 described above is applied, communication can be performed on the assumption that
there is no radio communication device corresponding only to a lower communication
scheme for a predetermined time. For example, the above-described third embodiment
of the present invention can be applied for the predetermined time. Also, when it is
given-as setting information that no radio communication device corresponding to a
25 specific communication scheme is in the radio communication system 1, the third
embodiment of the present invention can be applied.
[0083]
(3-3-3. Effect of Present Embodiment)
In the above-described third embodiment of the present invention, unnecessary
30 pieces of information among a plurality of pieces of decoding information can be
omitted, and it is possible to further suppress overhead according to the situation in
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which communication schemes coexist.
[0084]
SP262712 W000
[3-4. Fourth Embodiment]
(3-4-1. Operation of Radio Communication Device during Data Transmission)
5 Fig. 10 is a flowchart illustrating operation of the radio communication device
100 relating to a fourth embodiment of the present invention during data transmission.
[0085]
First, the packet generation unit 155 reads data 210 stored in the data buffer 153
(step S301). Next, the packet generation unit 155 adds third decoding information 203
10 including information for decoding the data 210 according to the third communication
scheme to the data 210 (step S303).
[0086]
Here, the control unit 165 determines whether or not the second communication
scheme is being used within a range in which a packet 200 is transmitted (step S305).
15 For example, when it is a time in which a radio communication device that corresponds
to the second communication scheme but does not correspond to the third
communication scheme is performing a reception operation due to a previously
transmitted packet 200, the control unit 165 can determine that the second
communication scheme is not being used.
20 [0087]
When the second communication scheme is being used in the radio
communication system 1, the packet generation unit 155 adds second decoding
information 202 to the data 210 (step S307). When the second communication scheme
is not being used, this step is skipped.
25 [0088]
In addition, the control unit 165 determines whether or not the first
communication scheme is being used within the range in which the packet 200 is
transmitted (step S309). For example, when it is a time in which a radio
communication device that corresponds only to the first communication scheme is
30 performing a reception operation due to the previously transmitted packet 200, the
control unit 165 can determine that the first communication scheme is not being used.
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[0089]
When the first communication scheme is being used in the radio communication
system 1, the packet generation unit 155 adds first decoding information 201 to the data
210 (step S311). When the first communication scheme is not being used, this step is
5 skipped.
[0090]
Through this process, the packet 200 is generated. The transmission unit 157
transmits the generated packet 200 through the antenna 159 (step S313).
[0091]
10 (3-4-2. Operation of Radio Communication Device During Data Reception)
Fig. 11 is a flowchart illustrating operation during data reception of the radio
communication device 100 relating to the fourth embodiment of the present invention.
[0092]
First, the reception unit 161 receives a packet 200 through the antenna 159 (step
15 S401). Next, the packet analysis unit 163 analyzes initial decoding information
included in the packet 200 (step S403).
[0093]
Here, the control unit 165 determines whether or not the analyzed decoding
information is valid decoding information (step S40S). For example, when the
20 analyzed decoding information is not valid decoding information such as decoding
information of a higher class not to be handled by the radio communication device 100,
the control unit 165 causes the reception unit 161 to finish a packet receiving operation.
When previously analyzed decoding information has been stored in the storage unit 167,
the control unit 165 sets only a time calculated from a packet length and a transmission
25 rate included in the decoding information as a transmission suppression period (step
S407).
[0094]
When the decoding information analyzed in step S403 is valid decoding
information, the control unit 165 determines whether or not the radio communication
30 device 100 corresponds to a communication scheme of a higher class than a
communication scheme of the analyzed decoding information (step S409). When the
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radio communication device 100 corresponds to a communication scheme of a higher
class than the communication scheme of the analyzed decoding information, the control
unit 165 additionally determines whether or not continuation information is included in
the analyzed decoding information (step S41 1).
5 [0095]
When the radio communication device 100 does not correspond to a
communication scheme of a higher class than the communication scheme of the
decoding information analyzed in step S403, or no continuation information has been
included in the analyzed decoding information, the control unit 165 determines the
to analyzed decoding information as decoding information for decoding the data 210.
[0096]
At this time, the control unit 165 additionally determines whether or not the
radio communication device 100 corresponds to the packet length, the transmission rate
and the like included in the decoding information (step S413). This is because there is
15 a case in which the same communication scheme is not able to correspond to all of
transmission rates and the like.
[0097]
When the radio communication device 100 does not correspond to the packet
length, the transmission rate and the like included in the decoding information, the
20 control unit 165 causes the reception unit 161 to finish the packet receiving operation,
and sets only a time calculated from the packet length and the transmission rate included
in the decoding information as a transmission suppression period (step S415).
[0098]
When the radio communication device 100 corresponds to the packet length, the
25 transmission rate and the like included in the decoding information, the control unit 165
causes the reception unit 161 to keep performing the reception operation to receive the
data 210 for the time calculated from the packet length and the transmission rate
included in the decoding information.
[0099]
30 When the radio communication device 100 corresponds to a communication
scheme of a higher class than the communication scheme of the decoding information
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analyzed in step S403 (step S409) and continuation information has been included in the
analyzed decoding information (step S411), the control unit 165 stores the analyzed
decoding information in the storage unit 167 (step 5419) and starts analysis of the next
decoding information (step S403).
5 [0100]
<4. Additions>
The preferred embodiments of the present invention have been described above
with reference to the accompanying drawings, whilst the present invention is not limited
to the above examples, of course. A person skilled in the art may find various
10 alternations 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
invention.
[0101]
For example, the embodiments are applied to the case in which three
15 communication schemes constituting classes coexist, but the present invention is not
limited to this example. For example, the embodiments may be applied to a case in
which four or more communication schemes constituting classes coexist.
[0102]
In other words, the first communication scheme may not be the lowest class.
20 Also, the second communication scheme may not be a class immediately above the first
communication scheme. Furthermore, the third communication scheme may be neither
a class immediately above the second communication scheme nor the highest class.
[0103]
Also in this case, by applying provision of a packet length and a transmission
25 rate for causing a radio communication device corresponding only to a lower
communication scheme to keep performing a reception operation, extension of a time for
causing a radio communication device corresponding to a specific communication
scheme to keep performing a reception operation, omission of decoding information of a
communication scheme not present within a range in which a packet is transmitted, and
30 the like in the sane way as to the embodiments of the present invention, it is possible to
realize coexistence of communication schemes of the respective classes while
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suppressing overhead.
Reference Signs list
[0104]
5 100 Radio communication device
151 Interface
153 Data buffer
155 Packet generation unit
157 Transmission unit
10 159 Antenna
161 Reception unit
163 Packet analysis unit
165 Control unit
167 Storage unit
15 200 Packet
201 First decoding information
202 Second decoding information
203 Third decoding information
210 Data
20 221 First continuation information
222 Second continuation information
ti First duration
t2 Second duration
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26/3 1
CLAIMS
Claim I
SP262712WO00
A radio communication device comprising:
a packet generation unit for generating a packet including first decoding
5 information that can be recognized by a radio communication device corresponding to a
first communication scheme, second decoding information that can be recognized by a
radio communication device corresponding to a second communication scheme and
third decoding information that can be recognized by a radio communication device
corresponding to a third communication scheme; and
10 a transmission unit for transmitting the packet generated by the packet
generation unit.
Claim 2
The radio communication device according to claim 1,
15 wherein the radio communication device corresponding to the first
communication scheme corresponds only to the first communication scheme,
wherein the radio communication device corresponding to the second
communication scheme also corresponds to the first communication scheme, and
wherein the radio communication device corresponding to the third
20 communication scheme also corresponds to the first communication scheme and the
second communication scheme.
Claim 3
The radio communication device according to claim 2,
25 wherein the packet includes the second decoding information following the first
decoding information, and the third decoding information following the second decoding
information.
Claim 4
30 The radio communication device according to claim 3,
wherein the first decoding information includes information for calculating a
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first duration in which the radio communication device corresponding only to the first
communication scheme is caused to keep performing a receiving operation, and
wherein the second decoding information includes information for calculating a
second duration in which the radio communication device that corresponds to the second
5 communication scheme but does not correspond to the third communication scheme is
caused to keep performing a receiving operation.
Claim 5
The radio communication device according to claim 4,
10 wherein the first duration and the second duration end at different times.
Claim 6
The radio communication device according to claim 3,
wherein the first decoding information includes first continuation information
15 indicating presence of the second decoding information to the radio communication
device corresponding to the second communication scheme and the radio
communication device corresponding to the third communication scheme, and
wherein the second decoding information includes second continuation
information indicating presence of the third decoding information to the radio
20 conununication device corresponding to the third communication scheme.
Claim 7
The radio communication device according to claim 1,
wherein, when the radio communication device corresponding only to the first
25 communication scheme is not within a range in which the packet is transmitted, the
packet generation unit generates the packet without the first decoding information.
Claim 8
30
The radio communication device according to claim 1,
wherein, when the radio communication device that corresponds to the second
communication scheme but does not correspond to the third communication scheme is
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not within a range in which the packet is transmitted, the packet generation unit
generates the packet without the second decoding information.
Claim 9
5 A radio communication device comprising:
a reception unit for receiving a packet including first decoding information that
can be recognized by a radio communication device corresponding to a first
communication scheme, second decoding information that can be recognized by a radio
communication device corresponding to a second communication scheme, and third
to decoding information that can be recognized by a radio communication device
corresponding to a third communication scheme; and
a packet analysis unit for analyzing the packet received by the reception unit.
Claim 10
15 The radio communication device according to claim 9,
wherein the packet includes the second decoding information following the first
decoding information, and the third decoding information following the second decoding
information.
20 Claim 11
The radio communication device according to claim 10,
wherein the receiving unit corresponds to the first communication scheme, the
second communication scheme and the third communication scheme, and keeps
performing a receiving operation on the basis of information included in the third
25 decoding information.
Claim 12
The radio communication device according to claim 10,
wherein the first decoding information includes first continuation information
30 indicating presence of the second decoding information to the radio communication
device corresponding to the second communication scheme and the radio
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communication device corresponding to the third communication scheme, and
wherein the second decoding information includes second continuation
information indicating presence of the third decoding information to the radio
communication device corresponding to the third communication scheme.
5
Claim 13
A radio communication method comprising the steps of:
generating a packet including first decoding information that can be recognized
by a radio communication device corresponding to a first communication scheme,
10 second decoding information that can be recognized by a radio communication device
corresponding to a second communication scheme and third decoding information that
can be recognized by a radio communication device corresponding to a third
communication scheme; and
transmitting the packet generated in the generating step.
15
Claim 14
A radio communication method comprising the steps of
receiving a packet including first decoding information that can be recognized
by a radio communication device corresponding to a first communication scheme,
20 second decoding information that can be recognized by a radio communication device
corresponding to a second communication scheme, and third decoding information that
can be recognized by a radio communication device corresponding to a third
communication scheme; and
- analyzing the packet received in the receiving step.
25
Claim 15
A radio communication system comprising:
a first radio communication device having a packet generation unit for
generating a packet including first decoding information that can be recognized by a
30 radio communication device corresponding to a first communication scheme, second
decoding information that can be recognized by a radio communication device
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5
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corresponding to a second communication scheme and third decoding information that
can be recognized by a radio communication device corresponding to a third
communication scheme, and a transmission unit for transmitting the packet generated by
the packet generation unit; and
a second radio communication device having a reception unit for receiving the
packet, and a packet analysis unit for analyzing the packet received by the reception
unit.