JP6416619B2 - Wireless communication apparatus, wireless communication method, and computer program - Google Patents

Description

  The present invention relates to a wireless communication device, a wireless communication method, and a computer program.

  In a communication network, protocols are multi-layered by a seven-layer model of an OSI (Open Systems Interconnection) reference model, and protocol design is performed for each layer. In Patent Document 1, based on such a hierarchical protocol design, a wireless communication apparatus capable of performing wireless resource allocation in consideration of upper layer information such as QoS (Quality of Service) required by an application layer is disclosed. Disclose. In Patent Document 2, the bandwidth occupancy for each access category assigned by the higher protocol layer is determined. If the bandwidth occupancy is equal to or greater than the threshold, the random delay setting range (CWmin and CWmax) of the priority control parameter is set to a predetermined value. Disclosed is a wireless LAN communication device that reduces the collision probability and transmission delay by increasing temporarily only. In Non-Patent Document 1, a value (Fake section) that is dynamically changed according to the communication status is added during the NAV (Network Allocation Vector) period of the RTS (Request To Send) frame, and the Fake section is added except for the proposed terminal. A method of increasing the transmission opportunity of the proposed terminal by waiting is disclosed.

JP 2009-224836 A International Publication No. 2012/120772

Yuta Kumagai, Satoshi Ohzato, Yasuhiko Kato, “High-priority media access control using dynamic control of NAV period in wireless LAN”, IEICE, IEICE Technical Report, vol. 112, no. 494 , AN2012-73, pp. 131-136, March 2013

  However, in the above-described conventional technology, when the wireless section is congested, there is a possibility that a wireless communication period corresponding to a period for which communication is desired to be guaranteed in an upper protocol layer cannot be secured.

  The present invention has been made in consideration of such circumstances, and a wireless communication device, a wireless communication method, and a wireless communication device that can contribute to securing a wireless communication period corresponding to a period in which communication is desired to be guaranteed in an upper protocol layer or the like, It is another object of the present invention to provide a computer program.

(1) According to an aspect of the present invention, a short signal transmission unit that repeatedly transmits a short signal at a time interval shorter than a time when wireless communication devices around the wireless communication device end standby for signal transmission, and the short signal A data transmission unit for transmitting a data signal during a period in which the transmission unit repeatedly transmits the short signal, and the time interval for the repeated transmission of the short signal is set to DIFS from the data transfer time of the short signal to the data transfer time. It is a wireless communication apparatus that is between values obtained by adding .
(2) According to one aspect of the present invention, a short signal transmission unit that repeatedly transmits a short signal at a time interval shorter than a time when wireless communication devices around the wireless communication device end standby for signal transmission, and the short signal A data transmission unit that transmits a data signal during a period in which the transmission unit repeatedly transmits the short signal, and the short signal is a CTS (Clear to Send) frame signal, and a NAV (Network The Allocation Vector) period is the time from the transmission of the transmission data waiting for transmission to the completion of reception of the acknowledge signal when there is transmission data waiting for transmission, and 0 when there is no transmission data waiting for transmission. A wireless communication device.
(3) According to one aspect of the present invention, a short signal transmission unit that repeatedly transmits a short signal at a time interval shorter than a time when wireless communication apparatuses around the wireless communication apparatus end standby for signal transmission, and the short signal A data transmission unit that transmits a data signal during a period in which the transmission unit repeatedly transmits the short signal, the short signal is a CTS (Clear to Send) frame signal, and the transmission of the CTS frame signal is a CTS frame After receiving the signal, the wireless communication apparatus waits for a random time in a range from the NAV period to a value obtained by adding DIFS to the NAV period .
(4) According to one aspect of the present invention, a short signal transmission unit that repeatedly transmits a short signal at a time interval shorter than a time when wireless communication devices around the wireless communication device end standby for signal transmission; and the short signal A data transmission unit that transmits a data signal during a period in which the transmission unit repeatedly transmits the short signal, and the start time of the repeated transmission of the short signal is determined from the specified period start time around the wireless communication device This is a wireless communication device that is a time traced back by the data transfer time of the maximum data frame length of the wireless communication device.
( 5 ) One aspect of the present invention is the wireless communication apparatus according to any one of (1) to (4) , wherein the data transmission unit does not perform carrier sense before transmitting the data signal.
( 6 ) One aspect of the present invention is the wireless communication apparatus according to any one of (1) to (5) , wherein the short signal is transmitted at a minimum rate of MCS (Modulation and Coding Scheme).
(7) In one aspect of the present invention, from an upper communication protocol layer, and a period information receiving unit for receiving period information indicating a period start time of the period to be guaranteed communications and period end time, the above (1) The wireless communication device according to any one of (6) .

( 8 ) According to one aspect of the present invention, the short signal transmission unit repeatedly transmits the short signal at a shorter time interval than the wireless communication devices around the own wireless communication device finish waiting for signal transmission. step a, the data transmission unit, a data transmission step of transmitting a data signal during a period in which the short signal transmission unit transmits repeatedly the short signal, seen including a time interval of repeated transmission of the short signal is short signals This is a wireless communication method that is between the data transfer time and the value obtained by adding DIFS to the data transfer time .
(9) According to one aspect of the present invention, the short signal transmission unit repeatedly transmits the short signal at a shorter time interval than the wireless communication devices around the own wireless communication device finish waiting for signal transmission. A data transmission step in which the data transmission unit transmits a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal, and the short signal is a CTS (Clear to Send) frame signal. The NAV (Network Allocation Vector) period indicated by the CTS frame signal is the time from the transmission of the transmission data waiting for transmission to the completion of the reception of the acknowledge signal when there is transmission data waiting for transmission. This is a wireless communication method in which 0 is set when there is no waiting transmission data.
(10) According to one aspect of the present invention, the short signal transmission unit repeatedly transmits the short signal at a shorter time interval than the wireless communication devices around the own wireless communication device finish waiting for signal transmission. A data transmission step in which the data transmission unit transmits a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal, and the short signal is a CTS (Clear to Send) frame signal. The transmission of the CTS frame signal is a wireless communication method in which after receiving the CTS frame signal, the CTS frame signal waits for a random time from the NAV period to a value obtained by adding DIFS to the NAV period.
(11) According to one aspect of the present invention, the short signal transmission unit repeatedly transmits the short signal at a time interval shorter than the wireless communication devices around the own wireless communication device finish waiting for signal transmission. And a data transmission step in which the data transmission unit transmits a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal, and a start time of the repeated transmission of the short signal is designated This is a wireless communication method, which is a time that is retroactive from the period start time by the data transfer time of the maximum data frame length of the wireless communication devices around the wireless communication device.

( 12 ) One embodiment of the present invention is a short circuit in which a short signal is repeatedly transmitted to a computer included in a wireless communication device repeatedly at a time interval shorter than a time when wireless communication devices around the wireless communication device end standby for signal transmission. A computer program for executing a signal transmission step and a data transmission step of transmitting a data signal during a period in which the short signal transmission step repeatedly transmits the short signal, and a time interval of the repeated transmission of the short signal is The computer program is between the data transfer time of the short signal and the value obtained by adding DIFS to the data transfer time .
(13) One embodiment of the present invention is a short circuit in which a short signal is repeatedly transmitted to a computer included in a wireless communication device repeatedly at a shorter time interval than wireless communication devices around the wireless communication device end standby for signal transmission. A computer program for executing a signal transmission step and a data transmission step of transmitting a data signal during a period in which the short signal transmission step repeatedly transmits the short signal, wherein the short signal is CTS (Clear to Send) A NAV (Network Allocation Vector) period indicated by the CTS frame signal is a frame signal, and when there is transmission data waiting to be transmitted, the period from the transmission of the transmission data waiting for transmission to the completion of reception of the acknowledge signal A computer program that sets time and 0 when there is no transmission data waiting to be transmitted A.
(14) One embodiment of the present invention is a short circuit in which a short signal is repeatedly transmitted to a computer included in a wireless communication device repeatedly at a time interval shorter than a time when wireless communication devices around the wireless communication device end standby for signal transmission. A computer program for executing a signal transmission step and a data transmission step of transmitting a data signal during a period in which the short signal transmission step repeatedly transmits the short signal, wherein the short signal is CTS (Clear to Send) The transmission of the CTS frame signal is a computer program that waits for a random time from the NAV period to the value obtained by adding DIFS to the NAV period after receiving the CTS frame signal.
(15) One embodiment of the present invention is a short circuit in which a short signal is repeatedly transmitted to a computer included in a wireless communication device repeatedly at a time interval shorter than a time when wireless communication devices around the wireless communication device end standby for signal transmission A computer program for executing a signal transmission step and a data transmission step of transmitting a data signal during a period in which the short signal transmission step repeatedly transmits the short signal, and a start time of the repeated transmission of the short signal is This is a computer program that is a time that is backed by the data transfer time of the maximum data frame length of the wireless communication devices around the specified wireless communication device from the specified period start time.

  According to the present invention, there is an effect that it is possible to contribute to securing a wireless communication period corresponding to a period in which communication is desired to be guaranteed in an upper protocol layer or the like.

1 is a configuration diagram showing a wireless communication system 1 according to an embodiment of the present invention. It is a figure which shows the example of the short signal which concerns on one Embodiment of this invention. It is a flowchart which shows an example of operation | movement of the radio | wireless communication apparatus 10 which concerns on one Embodiment of this invention. It is explanatory drawing of the radio | wireless communications system 1 which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram showing a wireless communication system 1 according to an embodiment of the present invention. The wireless communication system 1 according to the present embodiment includes a plurality of wireless communication devices. The wireless communication system 1 shown in FIG. 1 includes four wireless communication devices 10, 20, 30, and 40 for convenience of explanation. The wireless communication device 10 transmits a data signal including transmission data to the wireless communication device 20 by wireless communication. When receiving the data signal from the wireless communication device 10, the wireless communication device 20 transmits an acknowledge (ACK) signal indicating that the reception is completed to the wireless communication device 10.

  The wireless communication device 10 illustrated in FIG. 1 includes a transmission unit 100, a period information reception unit 101, a start time determination unit 102, and an end time determination unit 103. The transmission unit 100 includes a data transmission unit 104, a short signal transmission unit 105, and a data transmission unit 106.

  The period information receiving unit 101 receives the period information A. The period information A indicates the specified period start time ST and period end time SP. The period information A indicates, for example, a period start time ST and a period end time SP of a period for which communication is desired to be guaranteed. The period information receiving unit 101 receives period information A from, for example, an upper communication protocol layer. The period information A indicates, for example, a period start time ST and a period end time SP of a period for which a host application wants to guarantee communication. An example of the upper application is an application that performs real-time processing.

  An example of the higher-order application is an application that provides virtual reality data to the wireless communication device 20. The wireless communication apparatus 20 includes, for example, a haptic sensing / feedback device capable of presenting a haptic sensation. The tactile force sensing / feedback device of the wireless communication device 20 presents a tactile force sense based on the data received from the wireless communication device 10. Thereby, a tactile sensation is presented to the user having the wireless communication device 20. For example, the upper application of the wireless communication device 10 notifies the wireless communication device 20 of the timing at which a player hits a tennis ball during a tennis match. In this case, the period information A transmitted from the upper application of the wireless communication apparatus 10 to the period information receiving unit 101 includes the period start time ST and the period end time SP of the period in which the tennis ball is assumed to arrive at the player. Indicates. During the period from the period start time ST to the period end time SP indicated by the period information A, the tennis ball hits the player from the upper application of the radio communication device 10 to the tactile force sensing / feedback device of the radio communication device 20. If the timing to be struck is notified, the user having the wireless communication device 20 hits the tennis ball in the virtual space, and as the feedback of the tactile sensation, the accurate timing to present the tactile sensation from the haptic sensing / feedback device It becomes. For this reason, in this embodiment, the period from the period start time ST indicated by the period information A to the period end time SP is secured as a radio communication period for transmitting a data signal from the radio communication apparatus 10 to the radio communication apparatus 20. Plan.

  The period information receiving unit 101 outputs the received period information A to the start time determining unit 102 and the end time determining unit 103.

  Based on the period start time ST indicated by the period information A, the start time determination unit 102 determines a start time S1 that is a time for starting repeated transmission of the short signal. The start time determination unit 102 notifies the transmission unit 100 of the determined start time S1. Based on the period information A, the end time determination unit 103 determines an end time S2, which is a time to end the repeated transmission of the short signal, based on the period end time SP indicated by the period information A. The end time determination unit 103 notifies the transmission unit 100 of the determined end time S2.

  The transmission unit 100 transmits a radio signal. The data transmission units 104 and 106 transmit a data signal among wireless signals. The data transmission unit 104 performs carrier sense before transmitting a data signal to check whether there is a free wireless channel, and transmits a data signal using the free wireless channel only when there is a free wireless channel. To do. On the other hand, the data transmission unit 106 transmits a data signal using a radio channel without performing carrier sense before transmitting the data signal.

  The short signal transmission unit 105 transmits a short signal among radio signals. The short signal transmission unit 105 transmits a short signal using a radio channel without performing carrier sense before transmitting the short signal. The radio channel through which the short signal transmission unit 105 transmits a short signal is the same as the radio channel through which the data transmission unit 106 transmits a data signal. The short signal transmission unit 105 starts repetitive transmission of the short signal at the start time S1. The short signal transmission unit 105 ends the repeated transmission of the short signal at the end time S2.

  In the wireless communication system 1, the wireless communication devices 10, 20, 30, 40 wait for transmission of a signal using the wireless channel that has received the short signal for at least a predetermined transmission waiting time Th after receiving the short signal. . The short signal transmission unit 105 repeatedly transmits the short signal with the time interval TI between the last bit of the short signal and the start bit of the next short signal as an interval less than the transmission standby time Th. As a result, the other radio communication devices 20, 30, and 40 that receive the short signal transmitted from the radio communication device 10 receive the next short signal before the transmission standby time Th elapses after receiving the short signal. Therefore, it continues to wait for transmission of a signal using the wireless channel that has received the short signal. Therefore, the wireless communication device 10 can secure a wireless communication period for transmitting a data signal using a wireless channel for transmitting a short signal. Thus, if the data transmission unit 106 uses a wireless channel in which a wireless communication period is ensured by transmission of a short signal for transmission of the data signal, transmission can be performed without performing carrier sense before transmitting the data signal. Data collision can be avoided.

  As the transmission standby time Th, for example, the time taken for the wireless communication devices 10, 20, 30, and 40 to determine the unused state of the wireless channel in the carrier sense can be mentioned. Thereby, the other radio communication devices 20, 30, 40 that receive the short signal transmitted from the radio communication device 10 are in an unused state after receiving the short signal for the radio channel that has received the short signal. Since the next short signal is received before the determination, it is determined by the carrier sense that the radio channel is still in use and the transmission of the data signal using the radio channel is kept waiting. Therefore, the wireless communication device 10 can secure a wireless communication period for transmitting a data signal using a wireless channel for transmitting a short signal.

  FIG. 2 is a diagram illustrating an example of a short signal according to the present embodiment. In the example of FIG. 2, the short signal is a CTS (Clear To Send) frame signal. The CTS frame signal is used in a wireless LAN wireless communication apparatus that conforms to the IEEE 802.11 standard. The frame structure of the CTS frame signal consists of a total of 14 octets including a frame control field (2 octets), a duration field (2 octets), a receiver address field (6 octets), and an FCS field (4 octets).

  In a wireless LAN wireless communication apparatus compliant with the IEEE 802.11 standard, the time taken to determine whether a wireless channel is not used in carrier sense is DIFS (Distributed Access Inter Frame Space). Therefore, the time interval TI when the short signal transmission unit 105 repeatedly transmits the short signal is expressed as “T ≦ TI ≦ (T + DIFS)” using the short signal transfer time T and DIFS. be able to. Thereby, as illustrated in FIG. 2, the wireless communication device 10 transmits the next CTS frame signal before the DIFS has elapsed since the transmission of the CTS frame signal. The other wireless communication devices 20, 30, and 40 that receive the CTS frame signal transmitted from the wireless communication device 10 receive the CTS frame signal for the wireless channel that has received the CTS frame signal before the DIFS has elapsed. Since the next CTS frame signal is received, it is determined by carrier sense that the radio channel is still in use, and the transmission of a data signal using the radio channel is kept waiting. Therefore, the wireless communication device 10 can secure a wireless communication period for transmitting a data signal using a wireless channel for transmitting a CTS frame signal.

  An RTS (Request to Send) frame signal may be used as the short signal. However, the frame structure of the RTS frame signal is 20 octets obtained by adding a transmitter address (6 octets) to the frame structure of the CTS frame signal. For this reason, the signal using the CTS frame signal as the short signal can reach the signal farther without error.

  Next, an example of the operation of the wireless communication device 10 according to the present embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing an example of the operation of the wireless communication device 10 according to the present embodiment. In the following description, a CTS frame signal is taken as an example of a short signal.

(Step S10) The period information receiving unit 101 receives period information A from, for example, an upper communication protocol layer. The period information receiving unit 101 acquires the period start time ST and the period end time SP from the received period information A.

(Step S20) The start time determination unit 102 uses the period start time ST and the data transfer time MT of the maximum data frame length of the radio communication devices 20, 30, and 40 around the own radio communication device 10, and The start time S1 is determined by “start time S1 = ST−MT”. The determined start time S1 is a time that is traced back from the period start time ST by the data transfer time MT of the maximum data frame length of the radio communication devices 20, 30, and 40 around the own radio communication device 10. In this way, even when other wireless communication devices 20, 30, 40 other than the wireless communication device 10 are transmitting data, other wireless communication is performed by receiving the short signal before the period start time ST. The devices 20, 30, and 40 can be shifted to a transmission standby state by carrier sense.

(Step S30) The end time determination unit 103 uses the period end time SP and DIFS to determine the end time S2 by “end time S2 = SP-DIFS”. According to the determined end time S2, the resumption of data transmission of the wireless communication devices 20, 30, 40 other than the wireless communication device 10 can be made after the period end time SP.

(Step S40) The radio communication device 10 determines whether the current time is within the period from the start time S1 to the end time S2. If the current time is within the period (step S40; YES), the process proceeds to step S50. If the current time is out of the period (step S40; NO), the process ends.

(Step S50) The radio communication device 10 determines whether a CTS frame signal is received from another priority device. The other priority device is a wireless communication device in which the wireless communication device 10 is set in advance to be the priority device among the wireless communication devices 20, 30, and 40 other than the wireless communication device 10. The priority device has the same configuration as the wireless communication device 10. If the CTS frame signal is received (step S50; YES), the process proceeds to step S60. If a CTS frame has not been received (step S50; NO), the process proceeds to step S70.

(Step S60) The radio communication apparatus 10 sets the NAV period stored in the received CTS frame signal as the minimum value, sets the value obtained by adding DIFS to the NAV period as the maximum value, and ranges from the minimum value to the maximum value After waiting for a random time, the process proceeds to step S80.

(Step S70) The radio communication apparatus 10 sets the transfer time T of the CTS frame signal as the minimum value, sets the value obtained by adding DIFS to the transfer time T of the CTS frame signal as the maximum value, and ranges from the minimum value to the maximum value After waiting for a random time, the process proceeds to step S80. This standby in step S70 is preferable in order to avoid collision of transmission data between the wireless communication device 10 and another priority device.

(Step S80) The wireless communication apparatus 10 determines whether there is transmission data waiting to be transmitted. If there is transmission data waiting for transmission (step S80; YES), the process proceeds to step S90. If there is no transmission data waiting for transmission (step S80; NO), the process proceeds to step S110.

(Step S90) The short signal transmission unit 105 stores “data transfer time + ACK transmission wait time + ACK transfer time” as the NAV period in the duration field of the CTS frame signal to be transmitted. Thereafter, the process proceeds to step S100. The data transfer time is a transfer time of transmission data waiting for transmission. The ACK transmission waiting time is a transmission waiting time of the ACK signal. The ACK transfer time is the transfer time of the ACK signal.

(Step S100) The short signal transmission unit 105 transmits a CTS frame signal and a data signal. Thereafter, the process proceeds to step S130.

(Step S110) The short signal transmission unit 105 stores “0” as the NAV period in the duration field of the CTS frame signal to be transmitted. Thereafter, the process proceeds to step S120.

(Step S120) The short signal transmission unit 105 transmits a CTS frame signal. Thereafter, the process proceeds to step S130.

(Step S130) The radio communication device 10 determines whether the current time is within the period from the start time S1 to the end time S2. If the current time is within the period (step S130; YES), the process returns to step S50. If the current time is out of the period (step S130; NO), the process ends.

  In steps S90 and S110, the NAV period stored in the duration field of the CTS frame signal transmitted by the short signal transmission unit 105 contributes to ensuring fairness among the priority apparatuses that transmit the CTS frame signal. In step S90, the wireless communication device 10 has transmission data waiting for transmission. In this case, the NAV period stored in the duration field of the CTS frame signal transmitted by the short signal transmission unit 105 is defined as “data transfer time + ACK transmission wait time + ACK transfer time”. The NAV period indicated by the CTS frame signal is the time from the transmission of transmission data waiting for transmission to the completion of reception of the acknowledge signal. On the other hand, in step S110, the wireless communication device 10 has no transmission data waiting to be transmitted. In this case, the NAV period stored in the duration field of the CTS frame signal transmitted by the short signal transmission unit 105 is set to “0”.

  The other priority apparatus that has received the CTS frame signal waits for transmission of the CTS frame signal and the data signal only during a random time R within a range from the NAV period to the time obtained by adding DIFS to the NAV period. For example, when the NAV period is 800 μs, the random time R is a random number in a range of 800 ≦ R << (800 + DIFS). On the other hand, when the NAV period is 0, the random time R is a random number in the range of 0 ≦ R << DIFS. When the other priority device waits for the NAV period or longer, when the wireless communication device 10 transmits data, there is a possibility that data transmission may be hindered due to a collision with the CTS frame signal and the data signal of the other priority device. It can be avoided. In addition to ensuring the fairness between the priority devices by setting the waiting time for transmission of the CTS frame signal and the data signal to a random number in the range from the NAV period to the time obtained by adding DIFS to the NAV period. It is possible to keep other wireless communication devices other than the priority device waiting for transmission by carrier sense.

  According to the above-described embodiment, it is possible to contribute to securing a wireless communication period corresponding to a period for which communication is desired to be guaranteed in an upper protocol layer or the like by repeatedly transmitting a short signal.

  Note that the wireless communication device 10 may transmit data that does not have a high priority other than data that has a high priority and that requires a transmission period guarantee. For this reason, the data transmission unit 104 and the combination of the short signal transmission unit 105 and the data transmission unit 106 may be switched and used in accordance with an instruction from an upper protocol layer or the like.

  The wireless communication device 20 to which the wireless communication device 10 transmits a data signal preferably has the same configuration as the wireless communication device 10. This is because of the countermeasure against the hidden relationship between the wireless communication devices as shown in FIG. In FIG. 4, wireless communication devices 10 and 20 are priority devices having the configuration of the wireless communication device 10 shown in FIG. 1, and wireless communication devices 30 and 40 are non-priority devices. The signal reachable range of the wireless communication device 10 is A10, and the signal reachable range of the wireless communication device 20 is A20. Here, the signal of the wireless communication device 10 reaches the wireless communication devices 20 and 30, but does not reach the wireless communication device 40. On the other hand, the signal of the wireless communication device 20 reaches the wireless communication devices 10 and 40 but does not reach the wireless communication device 30. Therefore, in order to prevent the data signal from each of the wireless communication device 10 and the wireless communication device 20 from being alienated to the other wireless communication devices 30 and 40, the wireless communication device 10 and the wireless communication device 20 are repeatedly operated. It is preferable to transmit a short signal. It is also preferable that the short signal is transmitted at the minimum rate of MCS (Modulation and Coding Scheme). As a result, the noise resistance of the short signal is increased, and the signal can reach farther.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

Further, a computer program for realizing each step shown in FIG. 3 may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Here, the “computer system” may include an OS and hardware such as peripheral devices.
“Computer-readable recording medium” refers to a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disk), and a built-in computer system. A storage device such as a hard disk.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... Wireless communication system 10, 20, 30, 40 ... Wireless communication apparatus, 100 ... Transmission part, 101 ... Period information receiving part, 102 ... Start time determination part, 103 ... End time determination part, 104 ... Data transmission part, 105 ... Short signal transmission unit, 106 ... Data transmission unit

Claims (15)

A short signal transmission unit that repeatedly transmits a short signal at a time interval shorter than a wireless communication device around the wireless communication device ends waiting for signal transmission; and
A data transmission unit that transmits a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal ; and
The time interval for repeated transmission of the short signal is between the data transfer time of the short signal and the value obtained by adding DIFS to the data transfer time.
Wireless communication device. A short signal transmission unit that repeatedly transmits a short signal at a time interval shorter than a wireless communication device around the wireless communication device ends waiting for signal transmission; and
A data transmission unit that transmits a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal; and
The short signal is a CTS (Clear to Send) frame signal,
When there is transmission data waiting for transmission, the NAV (Network Allocation Vector) period indicated by the CTS frame signal is the time from the transmission of the transmission data waiting for transmission until the reception of the acknowledge signal is completed. 0 if there is no transmission data
Wireless communication device. A short signal transmission unit that repeatedly transmits a short signal at a time interval shorter than a wireless communication device around the wireless communication device ends waiting for signal transmission; and
A data transmission unit that transmits a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal; and
The short signal is a CTS (Clear to Send) frame signal,
The transmission of the CTS frame signal waits for a random time in a range from the NAV period to the value obtained by adding DIFS to the NAV period after receiving the CTS frame signal.
Wireless communication device. A short signal transmission unit that repeatedly transmits a short signal at a time interval shorter than a wireless communication device around the wireless communication device ends waiting for signal transmission; and
A data transmission unit that transmits a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal; and
The start time of the repeated transmission of the short signal is a time that is back from the specified period start time by the data transfer time of the maximum data frame length of the wireless communication device around the wireless communication device.
Wireless communication device. The wireless communication apparatus according to claim 1, wherein the data transmission unit does not perform carrier sense before transmitting the data signal. The short signal is a radio communications device according to any one of claims 1 5, which is transmitted by the lowest rate of MCS (Modulation and Coding Scheme). From the upper communication protocol layer, the radio communication apparatus according to any one of claims 1 to 6 comprising the period information receiving unit for receiving period information indicating a period start time of the period to be guaranteed communications and period end time . A short signal transmitting unit that repeatedly transmits a short signal at a time interval shorter than a wireless communication device around the wireless communication device ends waiting for signal transmission; and
Data transmission unit, viewed contains a data transmission step of transmitting a data signal during a period in which the short signal transmission unit transmits repeatedly the short signal,
The time interval for repeated transmission of the short signal is between the data transfer time of the short signal and the value obtained by adding DIFS to the data transfer time.
Wireless communication method. A short signal transmitting unit that repeatedly transmits a short signal at a time interval shorter than a wireless communication device around the wireless communication device ends waiting for signal transmission; and
A data transmission step for transmitting a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal;
The short signal is CTS (Clear to Send) frame signal,
The NAV (Network Allocation The Vector) period is the time from the transmission of the transmission data waiting for transmission until the completion of the reception of the acknowledge signal when there is transmission data waiting for transmission, and 0 when there is no transmission data waiting for transmission. ,
Wireless communication method. A short signal transmitting unit that repeatedly transmits a short signal at a time interval shorter than a wireless communication device around the wireless communication device ends waiting for signal transmission; and
A data transmission step for transmitting a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal;
The short signal is CTS (Clear to Send) frame signal,
The transmission of the CTS frame signal waits for a random time in a range from the NAV period to the value obtained by adding DIFS to the NAV period after receiving the CTS frame signal.
Wireless communication method. A short signal transmitting unit that repeatedly transmits a short signal at a time interval shorter than a wireless communication device around the wireless communication device ends waiting for signal transmission; and
A data transmission step for transmitting a data signal during a period in which the short signal transmission unit repeatedly transmits the short signal;
The start time of the repeated transmission of the short signal is a time that is back from the specified period start time by the data transfer time of the maximum data frame length of the wireless communication device around the wireless communication device.
Wireless communication method. In the computer provided in the wireless communication device,
A short signal transmission step of repeatedly transmitting a short signal at a time interval shorter than the wireless communication devices around the own wireless communication device finish waiting for signal transmission;
A data transmission step of transmitting a data signal during a period in which the short signal transmission step repeatedly transmits the short signal ;
The time interval for repeated transmission of the short signal is between the data transfer time of the short signal and the value obtained by adding DIFS to the data transfer time.
Computer program. In the computer provided in the wireless communication device,
A short signal transmission step of repeatedly transmitting a short signal at a time interval shorter than the wireless communication devices around the own wireless communication device finish waiting for signal transmission;
A data transmission step of transmitting a data signal during a period in which the short signal transmission step repeatedly transmits the short signal;
The short signal is CTS (Clear to Send) frame signal,
The NAV (Network Allocation The Vector) period is the time from the transmission of the transmission data waiting for transmission until the completion of the reception of the acknowledge signal when there is transmission data waiting for transmission, and 0 when there is no transmission data waiting for transmission. ,
Computer program. In the computer provided in the wireless communication device,
A short signal transmission step of repeatedly transmitting a short signal at a time interval shorter than the wireless communication devices around the own wireless communication device finish waiting for signal transmission;
A data transmission step of transmitting a data signal during a period in which the short signal transmission step repeatedly transmits the short signal;
The short signal is CTS (Clear to Send) frame signal,
The transmission of the CTS frame signal waits for a random time in a range from the NAV period to the value obtained by adding DIFS to the NAV period after receiving the CTS frame signal.
Computer program. In the computer provided in the wireless communication device,
A short signal transmission step of repeatedly transmitting a short signal at a time interval shorter than the wireless communication devices around the own wireless communication device finish waiting for signal transmission;
A data transmission step of transmitting a data signal during a period in which the short signal transmission step repeatedly transmits the short signal;
The start time of the repeated transmission of the short signal is a time that is back from the specified period start time by the data transfer time of the maximum data frame length of the wireless communication device around the wireless communication device.
Computer program.

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