JP2011188125A - Radio communication device, radio communication system, control method, and program - Google Patents

Abstract

A wireless communication system capable of preventing a decrease in throughput is provided.
A transmission side wireless communication apparatus A includes a sequence number indicating the number of remaining frames for burst transfer in a frame and transmits the frame to a reception side wireless communication apparatus B. The radio communication device B on the receiving side calculates the burst transfer end timing corresponding to the sequence number based on the sequence number included in the frame received by the radio communication device B. Then, when the calculated end timing is reached, it is determined whether it is necessary to forcibly end the reception of the frame for burst transfer. The reception of the transfer frame is forcibly terminated, and the reception of another frame after the burst transfer is resumed.
[Selection] Figure 1

Description

  The present invention relates to a technique for performing burst transfer.

  Compared with wired communication, wireless communication is more susceptible to communication paths, making it difficult to perform stable communication. However, the present situation is that high throughput is required even in such a communication environment.

  One technique for improving throughput in wireless communication is a wireless communication method using burst transfer. Burst transfer continuously transmits multiple frames to the same communication partner, and reduces overhead such as time for data transfer normal end confirmation processing and frame interval other than the transfer time of data to be actually transmitted. Is.

  As a wireless communication method using burst transfer, for example, there are a wireless communication method based on WiMedia PHY specifications and WiMedia MAC specifications by WiMedia Alliance. In this wireless communication method, after a long preamble frame, a short preamble frame or a long preamble frame is continuously transmitted / received at a short burst transfer frame interval without performing data transfer normal completion confirmation processing for each frame. Is the method.

  In this case, in the wireless communication device on the transmission side, information on the frame interval (information specifying whether the frame interval is for burst transfer) and information on the preamble type (long preamble or short preamble) are included in the header of the current frame. Information to be identified). Then, the radio communication device on the receiving side sets a reception waiting state for the subsequent frame based on the information on the frame interval included in the frame and the information on the preamble type.

  For example, when the information on the frame interval is information indicating the frame interval for non-burst transfer and the information on the preamble type is information indicating a long preamble, the receiving-side wireless communication device, After receiving the frame, it is determined that the burst transfer has been completed, the reception waiting state of the long preamble frame is set, and another frame after the burst transfer is received. In addition, the wireless communication device on the receiving side may receive information on a short preamble for burst transfer when the information on the frame interval is information indicating the frame interval for burst transfer and the information on the preamble type is information indicating a short preamble. Set the frame reception wait state and receive the burst transfer frame.

  However, under a communication environment that is easily affected by noise, it is conceivable that the reception of the frame fails, or that the frame is lost during burst transfer due to the occurrence of interrupt processing on the transmission side.

  For this reason, the wireless communication device on the receiving side may fail to receive the last frame in the burst transfer and cannot determine that the burst transfer has ended. In addition, the radio communication device on the receiving side cannot determine that the burst transfer has ended, and at this time, the information regarding the frame interval in the frame received immediately before the burst transfer is the burst transfer interval and the preamble. If the type-related information is a short preamble, it enters a state of waiting for receiving a preamble frame having a short burst transfer. As a result, other frames after the burst transfer cannot be normally received unless the reception wait state of the preamble frame having a short burst transfer is forcibly terminated. Even if the reception waiting state of a preamble frame with a short burst transfer is forcibly ended, if the time until the reception waiting state is forcibly ended is uselessly long, the receiving-side wireless communication device The number of frames that cannot be received increases, resulting in a decrease in throughput. For this reason, it is considered necessary to develop a mechanism for preventing a decrease in throughput.

  In addition, as a technical document filed prior to the present invention, there is a document that discloses a technique for improving throughput (for example, see Patent Document 1).

  In Patent Document 1 (Japanese Patent Laid-Open No. 2008-109471), a flag indicating the transfer of a plurality of frames and a transfer frame number indicating the number of frames are stored in the first frame of the plurality of frames. In addition, it is disclosed that a destination address is included in any one frame in a burst transfer.

  However, in the technique disclosed in Patent Document 1, if reception of the final frame in burst transfer fails, it cannot be determined that burst transfer has ended, and a reception wait state is maintained while maintaining the internal reception state. . For this reason, the technique disclosed in Patent Document 1 causes a reduction in throughput.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a wireless communication device, a wireless communication system, a control method, and a program capable of preventing a decrease in throughput.

  In order to achieve this object, the present invention has the following features.

<Wireless communication device>
A wireless communication apparatus according to the present invention is
A wireless communication device that performs burst transfer,
Transmission means for transmitting a frame including a sequence number indicating the number of remaining frames for burst transfer;
Based on the sequence number included in the received frame, calculating means for calculating the end timing of the burst transfer according to the sequence number;
When the end timing is reached, it is determined whether or not it is necessary to forcibly end the reception of the burst transfer frame. Means for forcibly terminating reception and resuming reception of another frame after burst transfer;
It is characterized by having.

<Wireless communication system>
A wireless communication system according to the present invention includes:
A wireless communication system including a first wireless communication device that performs burst transfer and a second wireless communication device,
The first wireless communication device is:
A transmission unit that includes a sequence number indicating the number of remaining frames for burst transfer in a frame and transmits the frame to the second wireless communication device;
The second wireless communication device is:
Based on the sequence number included in the received frame, calculating means for calculating the end timing of the burst transfer according to the sequence number;
When the end timing is reached, it is determined whether or not it is necessary to forcibly end the reception of the burst transfer frame. Means for forcibly terminating reception and resuming reception of another frame after burst transfer;
It is characterized by having.

<Control method>
The control method according to the present invention includes:
A control method performed by a wireless communication device that performs burst transfer,
A transmission step of transmitting a frame including a sequence number indicating the number of remaining frames for performing burst transfer;
Based on the sequence number included in the received frame, a calculation step for calculating the end timing of the burst transfer according to the sequence number;
When the end timing is reached, it is determined whether or not it is necessary to forcibly end the reception of the burst transfer frame. And a resuming step of forcibly terminating reception and resuming reception of another frame after burst transfer.

<Program>
The program according to the present invention is:
A program to be executed by a computer of a wireless communication device that performs burst transfer,
A transmission process in which a sequence number indicating the number of remaining frames for burst transfer is included in the frame and transmitted,
Based on the sequence number included in the received frame, a calculation process for calculating the end timing of burst transfer according to the sequence number;
When the end timing is reached, it is determined whether or not it is necessary to forcibly end the reception of the burst transfer frame. It is characterized in that the computer is executed to forcibly terminate reception and to resume the reception of another frame after burst transfer.

  According to the present invention, it is possible to prevent a decrease in throughput.

It is a figure which shows the system configuration example of the radio | wireless communications system of this embodiment. It is a figure which shows the example of a format of the frame used with the radio | wireless communications system of this embodiment. It is a figure which shows the example of a communication method in the burst transfer using a short preamble. It is a figure which shows the internal structural example of the radio | wireless communication apparatus which comprises the radio | wireless communications system of this embodiment. 6 is a diagram illustrating an example of processing operation of a radio communication device A on a transmission side. FIG. 6 is a diagram showing an example of processing operation of a radio communication device B on the receiving side. FIG.

<Outline of Wireless Communication System of this Embodiment>
First, the outline of the wireless communication system of the present embodiment will be described with reference to FIG.

  The wireless communication system according to the present embodiment is a wireless communication system that includes a first wireless communication apparatus A that performs burst transfer and a second wireless communication apparatus B.

  The first wireless communication apparatus A of the present embodiment includes a sequence number indicating the number of remaining frames for which burst transfer is performed, and transmits the frame to the second wireless communication apparatus B.

  The second wireless communication apparatus B of the present embodiment calculates the burst transfer end timing according to the sequence number based on the sequence number included in the frame received by the second wireless communication apparatus B. Then, when the calculated end timing is reached, it is determined whether it is necessary to forcibly end the reception of the frame for burst transfer. The reception of the transfer frame is forcibly terminated, and the reception of another frame after the burst transfer is resumed.

  As a result, the wireless communication system according to the present embodiment can receive another frame after the burst transfer when the end timing of the burst transfer is reached, thereby preventing a decrease in throughput. Hereinafter, the wireless communication system of the present embodiment will be described in detail with reference to the accompanying drawings.

<System configuration example of wireless communication system>
First, a system configuration example of the wireless communication system according to the present embodiment will be described with reference to FIG.

  The wireless communication system of the present embodiment includes a wireless communication device A and a wireless communication device B. In the present embodiment, the wireless communication device A is described as a transmission side, and the wireless communication device B is described as a reception side.

  The wireless communication system according to the present embodiment continuously transmits and receives a plurality of frames between the wireless communication apparatuses A and B without performing a data transfer normal end confirmation process for each frame. In this embodiment, a communication method based on WiMedia PHY specifications and WiMedia MAC specifications by the WiMedia Alliance is adopted as a wireless communication method, and burst mode communication therein will be described.

<Frame format>
Next, a frame format used in the wireless communication system of this embodiment will be described with reference to FIG.

  The format of each frame used when the wireless communication devices A and B of the present embodiment continuously transmit and receive a plurality of frames to the same communication partner includes a preamble 101, a header 102, and a payload 103, as shown in FIG. It consists of.

  The preamble 101 includes a known training signal. The header 102 includes information necessary for communication. The payload 103 includes data that is actually desired to be sent.

  There are two types of preamble 101, a long preamble case and a short preamble case. For the first frame in burst transfer, a long preamble is selected and used, and after the second frame, either one is selected and used.

  The header 102 includes a BM bit indicating information related to the frame interval with the subsequent frame, and a PT bit indicating information related to the preamble type. In addition, as an extension of the WiMedia communication system, a sequence number (SEQ) indicating the number of remaining frames in burst transfer is included.

  The BM bit is information for indicating the burst mode. In the case of burst transfer, BM = 1, and otherwise BM = 0. The PT bit is information for indicating the preamble type of the subsequent frame, and PT = 1 for the short preamble type and PT = 0 for the long preamble type. Further, in a frame-by-frame transmission / reception method that is not burst transfer, a frame using a long preamble is always used. In this case, BM = 0, PT = 0, and SEQ = 0.

<Example of communication method in burst transfer using short preamble>
Next, a communication method in burst transfer using a short preamble will be described with reference to FIG. FIG. 3 illustrates a case where the total number of frames for burst transfer is four.

  As shown in FIG. 3, the BM bit is BM = 1 except for the last frame, that is, in the first to third frames, because the frame interval with the subsequent frames is short. In the fourth frame which is the final frame, BM = 0.

  Regarding the PT bit, since the preamble of subsequent frames is short in the frames other than the last frame, that is, in the first to third frames, PT = 1. In the fourth frame, which is the final frame, PT = 0 since the frame after the end of burst transfer is always a long preamble frame.

  The sequence numbers SEQ are 3, 2, 1, 0 in the order of the first frame to the fourth frame (SEQ = 3 in the first frame, SEQ = 2 in the second frame, SEQ = in the third frame). 1, SEQ = 0 of the fourth frame).

  The MIFS shown in FIG. 3 represents each frame interval during burst transfer, and is shorter than the frame interval in transmission / reception that is not burst transfer.

  The preamble can be used for AGC (Auto Gain Control), frequency offset estimation processing, and the like. However, when the preamble is short, it is difficult to perform AGC and frequency offset estimation processing, as in the case where the preamble is long. For this reason, AGC and frequency offset estimation processing are performed in the first frame using a long preamble, and AGC and frequency offset estimation processing are omitted in the second and subsequent frames using a short preamble. The calculated gain value or frequency offset estimated value is used.

  However, if reception of the fourth frame, which is the last frame, fails, reception is waited while maintaining the state in which the frame finally received within the burst transfer (the state in which the frame with BM = 1 and PT = 1 has been received) is maintained. It becomes a state. That is, the reception wait state is maintained while the internal reception state of waiting for reception of a preamble frame having a short burst transfer is maintained. For this reason, if reception of the fourth frame, which is the final frame, fails, the frame after burst transfer cannot be received normally, leading to a reduction in throughput.

  For this reason, in the wireless communication system of this embodiment, the wireless communication apparatus A on the transmission side transmits a frame including a sequence number indicating the number of remaining frames for which burst transfer is performed. Then, the wireless communication device B on the receiving side calculates the end timing of burst transfer according to the sequence number based on the sequence number included in the received frame. Then, when the calculated end timing is reached, it is determined whether it is necessary to forcibly end the reception of the frame for burst transfer. The reception of the transfer frame is forcibly terminated, and the reception of another frame after the burst transfer is resumed. Thereby, since the frame after burst transfer can be received, it is possible to prevent a decrease in throughput. Hereinafter, specific control operations performed by the wireless communication devices A and B of the present embodiment will be described.

<Internal configuration example of wireless communication devices A and B>
First, an example of the internal configuration of the wireless communication devices A and B of the present embodiment will be described with reference to FIG. Note that the internal configuration examples of the wireless communication devices A and B of the present embodiment have substantially the same configuration, and will be described as the wireless communication device 10.

  The wireless communication device 10 of this embodiment includes an antenna 1, a transmission / reception unit 2, a sequence number calculation unit 3, a burst transfer end timing calculation unit 4, a reception forced end determination unit 5, and a control unit 6. Consists of.

  In the wireless communication device 10 of the present embodiment, at the time of data transmission, the control unit 6 transmits transmission data to the transmission / reception unit 2, and the transmission / reception unit 2 performs digital signal processing including error correction coding, compression coding, and digital modulation. To add a preamble. At this time, the transmission / reception unit 2 uses a long preamble or a short preamble specified by the control unit 6. Further, the transmission / reception unit 2 performs a conversion process from a digital signal to an analog signal and a frequency conversion process from a baseband signal to an RF signal. Thereafter, the transmission / reception unit 2 transmits the transmission data from the antenna 1 as a radio wave to the reception-side wireless communication device. If the BM bit is a frame with BM = 1, the control unit 6 controls the transmission / reception unit 2 to transmit at a short frame interval.

  In the wireless communication device 10 of the present embodiment, at the time of data reception, the transmission / reception unit 2 performs a frequency conversion process from an RF signal to a baseband signal, an extra frequency component removal process, an analog signal on the signal received by the antenna 1 To digital signal conversion. Further, the transmission / reception unit 2 performs a synchronization process using a preamble, performs various correction processes on the header 102 and the payload 103 shown in FIG. 2, performs digital signal processing including demodulation, decoding, and error correction, and sends the control unit 6 Pass digital data. Note that, when performing the above-described synchronization processing using the preamble, the transmission / reception unit 2 determines a reception waiting state of a frame to be received based on the information of the BM bit and PT bit received in the previous frame. When the information of the BM bit and the PT bit is not BM = 1 and PT = 1, the transmission / reception unit 2 enters a state of waiting for reception of a frame with a long preamble, and uses the preamble of the frame to perform AGC, frequency offset estimation processing, synchronization Perform processing. In addition, when the information of the BM bit and the PT bit is BM = 1 and PT = 1, the transmission / reception unit 2 is in a state of waiting for reception of a frame with a short preamble, and a gain value and a frequency offset estimation value calculated with a frame with a long preamble Perform synchronization processing using.

  When receiving a transmission command for burst transfer (including information on the total number of frames for burst transfer) from the control unit 6 during data transmission, the sequence number calculation unit 3 determines the total number of frames for burst transfer received from the control unit 6 Based on the information, a sequence number indicating the number of remaining burst transfer frames for each frame is calculated.

  For example, as shown in FIG. 3, in burst transfer, the first frame has a value of the total number of frames minus 1 (in FIG. 3, since the total number of frames is set to 4, it is 3). And 0 in the final frame. For frames that are not burst transfer, 0 is set. The sequence number calculation unit 3 notifies the control unit 6 of the calculated sequence number.

  The burst transfer end timing calculation unit 4 determines the burst transfer end timing based on the number of remaining frames (sequence number SEQ) of burst transfer when receiving a frame with BM = 1 and PT = 1 during data reception. calculate. The control unit 6 notifies the burst transfer end timing calculation unit 4 of the sequence number SEQ, so that the burst transfer end timing calculation unit 4 knows the number of remaining frames for burst transfer based on the sequence number SEQ. Can do. When the burst transfer end timing calculation unit 4 reaches the burst transfer end timing, the burst transfer end timing calculation unit 4 notifies the reception forced end determination unit 5 to that effect.

  Note that the burst transfer end timing is obtained by adding the adjustment time to the time obtained by multiplying the time per frame by the sequence number SEQ. However, the time per frame is the longest time that can be taken as a frame that can be burst-transferred, so that it is not erroneously determined that burst transfer has ended despite the presence of a burst-transfer frame. The adjustment time is the time from the time when the time obtained by multiplying the time per frame by the sequence number SEQ to the end of the frame. By calculating the end timing of burst transfer based on the number of remaining frames (sequence number SEQ) of burst transfer, the time per frame, and the adjustment time, the minimum necessary period is estimated, and the appropriate burst transfer The end timing can be calculated.

  The reception compulsory termination determination unit 5 receives the notification that the burst transfer end timing has been reached from the burst transfer end timing calculation unit 4, and the BM bit and PT included in the frame finally received by the wireless communication device Check the information with the bit. If the information of the BM bit and PT bit included in the frame finally received by the wireless communication device is BM = 1 and PT = 1, the reception of the final frame fails and the reception of the burst transfer frame is forced. It is determined that it is necessary to end automatically. Then, the control unit 6 is notified to forcibly terminate reception.

  The control unit 6 performs control such as generation of a predetermined frame format at the time of data transmission, control of a frame interval of burst transfer, and control of the transmission / reception unit 2 based on the preamble type at the time of data reception.

  For the PT bit at the time of frame format generation, the control unit 6 sets PT = 1 when the preamble type of the subsequent frame is short, and sets PT = 0 otherwise. For the BM bit, BM = 1 is set when the frame interval with the subsequent frame is a frame interval for burst transfer, and BM = 0 is set otherwise. For the sequence number SEQ, the sequence number received from the sequence number calculation unit 3 is used.

  The control unit 6 notifies the transmission / reception unit 2 of the above various information.If the PT bit of the previous frame is PT = 1, the control unit 6 instructs the transmission / reception unit 2 to use a short preamble, and if PT = 0, Instruct the transceiver 2 to use a long preamble. In addition, when BM = 1, the transmission / reception unit 2 is instructed to generate a frame at a burst transfer frame interval, and when BM = 0, a frame is generated at a more predetermined frame interval. The transmission / reception unit 2 is instructed as follows.

  The setting of the BM bit and the PT bit in burst transfer follows the method shown in FIG. In the transmission / reception method for each frame that is not burst transfer, a frame using a long preamble is always used, and BM = 0 and PT = 0.

  The BM bit and PT bit notified from the transmitting / receiving unit 2 to the control unit 6 at the time of data reception are used to determine the reception wait state for the subsequent frame, and when the frame reception fails, the control unit 6 The BM bit and PT bit of the received frame are held as final information. In addition, when the BM bit and PT bit notified from the transmission / reception unit 2 to the control unit 6 at the time of data reception are BM = 1 and PT = 1, the control unit 6 sends a sequence number to the burst transfer end timing calculation unit 4. Notify SEQ.

  In addition, when notified by the reception forced end determination unit 5 to forcibly end burst transfer reception, the control unit 6 forcibly ends the reception of the burst transfer frame, Control to resume frame reception.

  Note that the control unit 6 includes an application layer higher than the communication protocol layer.

<Processing operation example of wireless communication system of this embodiment>
Next, a processing operation example of the wireless communication system according to the present embodiment will be described with reference to FIGS. 5 and 6. In the present embodiment, a case will be described in which burst transfer including four frames using the short preamble frame shown in FIG. 3 is performed from the wireless communication apparatus A to the wireless communication apparatus B.

<Example of processing operation of wireless communication device A on transmission side>
First, an example of processing operation of the wireless communication apparatus A on the transmission side will be described with reference to FIG.

  When starting burst transfer, the control unit 6 notifies the sequence number calculation unit 3 of a transmission command in burst transfer (step S101). At this time, the control unit 6 notifies the sequence number calculation unit 3 of information (4 frames) on the total number of frames for burst transfer.

  When the sequence number calculation unit 3 receives a transmission command in burst transfer, the sequence number calculation unit 3 calculates the sequence number SEQ based on the information on the total number of frames in burst transfer (4 frames), and the remaining number for the first frame The number of burst transfer frames (3 frames) is calculated and notified to the control unit 6 (step S102).

  Next, the control unit 6 confirms whether it is the last frame of burst transfer (step S103). If it is not the last frame (step S103 / No), the control unit 6 receives the frame having information of BM = 1, PT = 1, SEQ = 3 as the first frame via the transmission / reception unit 2 and the antenna 1. To the wireless communication device B on the side (step S105).

  The control unit 6 performs the processing of steps S102 → S103 / No → S105 for the second frame and the third frame as well as the first frame described above. However, when the value of the sequence number SEQ calculated in the process of step S102 is the second frame, SEQ = 2, and in the third frame, SEQ = 1. In addition, since the information of the BM bit and PT bit in the previous frame for each frame, that is, the first frame and the second frame is BM = 1 and PT = 1, the first frame and the second frame, the second frame, The frame interval between the third frames is a frame interval for burst transfer. In addition, the preamble type used in the second frame and the third frame uses a short preamble. For this reason, in step S105, a frame having information of BM = 1, PT = 1, SEQ = 2 is transmitted as the second frame, and a frame having information of BM = 1, PT = 1, SEQ = 1 is sent. Transmit as the third frame.

  In the case of transmission processing of the fourth frame, which is the final frame, the control unit 6 sets the value of the sequence number SEQ calculated in step S102 to SEQ = 0. For this reason, the control unit 6 determines that it is the last frame of the burst transfer in the process of step S103 (step S103 / Yes), and sets the frame having the information of BM = 0, PT = 0, SEQ = 0 as the fourth frame. A frame (final frame) is transmitted to the radio communication apparatus B on the receiving side via the transmission / reception unit 2 and the antenna 1 (step S104). At this time, the control unit 6 uses a short preamble like the second frame and the third frame described above, and the frame interval between the third frame and the fourth frame (final frame) is the frame interval for burst transfer. To be sent.

<Example of processing operation of wireless communication device B on receiving side>
Next, an example of processing operation of the receiving-side wireless communication apparatus B will be described with reference to FIG.

  When the control unit 6 enters the reception state, it checks whether or not a frame with BM = 1 and PT = 1 has been received (step S201).

  When the control unit 6 receives the first frame of burst transfer transmitted from the wireless communication apparatus A via the antenna 1 and the transmission / reception unit 2, the control unit 6 transmits a frame having information of BM = 1, PT = 1, SEQ = 3. Will receive. Therefore, the control unit 6 determines that a frame with BM = 1 and PT = 1 has been received (step S201 / Yes), and notifies the burst transfer end timing calculation unit 4 of the sequence number SEQ = 3 included in the frame. (Step S202).

  The burst transfer end timing calculation unit 4 calculates the burst transfer end timing based on the sequence number SEQ notified from the control unit 6 (step S203). In this case, the burst transfer end timing calculation unit 4 adds the adjustment time to the time obtained by multiplying the longest time considered as one frame by the sequence number SEQ 3 ((the longest time × the sequence). The sequence number (SEQ = 3) + adjustment time) is a period in which the remaining burst transfer frames exist, and burst transfer end timing is calculated. However, the adjustment time in this case is the time from the time when the time obtained by multiplying the longest time considered as one frame by 3 which is the sequence number SEQ to the end of the first frame.

  Next, the burst transfer end timing calculation unit 4 checks whether or not the burst transfer end timing calculated in step S203 has been reached (step S204).

  When the wireless communication device B receives the first frame, the burst transfer end timing has not been reached (step S204 / No), so that the frame with BM = 1 and PT = 1 is waited for the reception of the next frame. It will not be received (step S201 / No). For this reason, the processing of step S202 and step S203 is omitted, and the confirmation of whether or not the burst transfer end timing of step S204 has been reached is repeated. In the next frame reception waiting state, since BM = 1 and PT = 1 are received in the first frame, a frame reception waiting state with a short burst transfer preamble is entered.

  When the wireless communication device B receives the second frame, the same processing as the first frame is performed except that the burst transfer end timing is updated. Also, when the wireless communication apparatus B receives the third frame, the same processing as that for the first frame is performed.

  Note that if the wireless communication device B has not received the fourth frame, which is the final frame, the wireless communication device B has not received the frame during the period in which the fourth frame should exist, so in step S201 No, and since the burst transfer end timing has not been reached, No is determined in step S204, and the processing of steps S201 / No → S204 / No is repeated until the burst end timing is reached. When the burst transfer end timing is reached (step S204 / Yes), the burst transfer end timing calculation unit 4 notifies the reception forced end determination unit 5 that the burst transfer end timing has been reached (step S205).

  The reception forced termination determination unit 5 confirms information on the BM bits and PT bits included in the final frame received by the wireless communication apparatus B, and confirms whether BM = 1 and PT = 1 are satisfied ( Step S206).

  In this case, since the reception of the fourth frame, which is the final frame, has failed, the information on the BM bit and the PT bit included in the final frame received by the wireless communication apparatus B is BM = 1, PT = 1 (Step S206 / Yes), the reception forced end determination unit 5 determines that it is necessary to forcibly end the reception of the burst transfer frame (step S207). Thereafter, the reception compulsory termination determination unit 5 notifies the control unit 6 to forcibly terminate reception of the burst transfer frame, and the control unit 6 receives the burst transfer frame when the notification is received. Is forcibly terminated, and control is performed so that reception of another frame after burst transfer is resumed.

  Also, when the wireless communication device B can receive the fourth frame, which is the final frame, it will receive a frame with BM = 0 and PT = 0, so it will not receive a frame with BM = 1 and PT = 1. If the burst transfer end timing has been reached (step S204 / Yes), the burst transfer end timing calculation unit 4 indicates that the burst transfer end timing has been reached, and the reception forced end determination unit 5 (Step S205). Then, the forced reception termination determination unit 5 confirms information on the BM bits and PT bits included in the final frame received by the wireless communication device B, and confirms whether BM = 1 and PT = 1 are satisfied. (Step S206).

  In this case, since the wireless communication device B can receive the fourth frame, which is the final frame, the information about the BM bit and the PT bit included in the final frame received by the wireless communication device B is BM = 1. PT = 1 is not satisfied (step S206 / No), and the reception forced end determination unit 5 determines that it is not necessary to forcibly end the reception of the burst transfer frame (step S209).

<Operation / Effect of Wireless Communication System of Present Embodiment>
As described above, in the wireless communication system according to the present embodiment, after a long preamble frame, a short preamble frame or a long preamble frame is confirmed for each frame at a short burst transfer frame interval. Use burst transfer for continuous transmission and reception without processing. In addition, the header of the current frame includes information regarding the frame interval of subsequent frames and information regarding the preamble type. In this case, the wireless communication device A on the transmission side includes a sequence number indicating the number of remaining frames for burst transfer in the header of each frame and transmits the sequence number to the wireless communication device B on the reception side. For example, when the total number of frames for burst transfer is 4, the sequence number SEQ is 3 in the first frame in burst transfer, and the sequence number SEQ is 0 in the fourth frame in burst transfer, that is, the last frame. Become. Then, the receiving-side radio communication device B can receive the frame including the sequence number SEQ so that the number of remaining burst transfer frames can be grasped based on the sequence number SEQ. B calculates the burst transfer end timing based on this sequence number SEQ. When the wireless communication device B on the receiving side reaches the burst transfer end timing, the information about the frame interval included in the frame finally received by the wireless communication device B on the receiving side is the frame interval for non-burst transfer. It is confirmed whether it is information indicating. Also, it is confirmed whether or not the information on the preamble type included in the frame finally received by the receiving-side radio communication apparatus B is information indicating a long preamble. If the information is not the frame interval for non-burst transfer and is not a long preamble, the wireless communication device B on the receiving side determines that reception of the last frame has failed and receives the burst transfer frame. It is forcibly terminated and reception of another frame after burst transfer is resumed. Thereby, since the radio | wireless communications system of this embodiment can receive the flame | frame after burst transfer, it can prevent the fall of a through-put.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

  For example, the control operation of each unit constituting the wireless communication apparatus of the present embodiment described above can be executed using hardware, software, or a combined configuration of both.

  In the case of executing processing using software, it is possible to install and execute a program in which a processing sequence is recorded in a memory in a computer incorporated in dedicated hardware. Alternatively, the program can be installed and executed on a general-purpose computer capable of executing various processes.

  For example, the program can be recorded in advance on a hard disk or ROM (Read Only Memory) as a recording medium. Alternatively, the program can be stored (recorded) temporarily or permanently in a removable recording medium. Such a removable recording medium can be provided as so-called package software. Examples of the removable recording medium include a floppy (registered trademark) disk, a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto optical) disk, a DVD (Digital Versatile Disc), a magnetic disk, and a semiconductor memory.

  In addition, the wireless communication device according to the present embodiment is not only executed in time series according to the processing operation described in the above embodiment, but also the processing capability of the device that executes the processing, or in parallel as necessary. It can also be constructed to run individually.

A, B Wireless communication apparatus 1 Antenna 2 Transmission / reception unit 3 Sequence number calculation unit 4 Burst transfer end timing calculation unit 5 Reception forced end determination unit 6 Control unit

JP 2008-109471 A

Claims (7)

A wireless communication device that performs burst transfer,
Transmission means for transmitting a frame including a sequence number indicating the number of remaining frames for burst transfer;
Based on the sequence number included in the received frame, calculating means for calculating the end timing of the burst transfer according to the sequence number;
When the end timing is reached, it is determined whether or not it is necessary to forcibly end the reception of the burst transfer frame. Means for forcibly terminating reception and resuming reception of another frame after burst transfer;
A wireless communication apparatus comprising: The calculating means includes
Included in the frame when the information regarding the frame interval included in the received frame is information indicating the frame interval for burst transfer, and the information regarding the preamble type included in the frame is information indicating a short preamble type. 2. The wireless communication apparatus according to claim 1, wherein a burst transfer end timing corresponding to the sequence number is calculated based on a sequence number to be transmitted. The calculating means includes
The time obtained by multiplying the time per frame by the sequence number and adding the time from the time when the time is obtained to the end of the received frame as the adjustment time is used as the burst transfer time. The wireless communication apparatus according to claim 1, wherein the wireless communication apparatus calculates the end timing. The restarting means includes
The information regarding the frame interval included in the frame finally received by the wireless communication apparatus is information indicating the frame interval for burst transfer, and the information regarding the preamble type included in the frame is information indicating the short preamble type. 4. The wireless communication apparatus according to claim 1, wherein in some cases, it is determined that it is necessary to forcibly terminate the wireless communication apparatus. 5. A wireless communication system including a first wireless communication device that performs burst transfer and a second wireless communication device,
The first wireless communication device is:
A transmission unit that includes a sequence number indicating the number of remaining frames for burst transfer in a frame and transmits the frame to the second wireless communication device;
The second wireless communication device is:
Based on the sequence number included in the received frame, calculating means for calculating the end timing of the burst transfer according to the sequence number;
When the end timing is reached, it is determined whether or not it is necessary to forcibly end the reception of the burst transfer frame. Means for forcibly terminating reception and resuming reception of another frame after burst transfer;
A wireless communication system comprising: A control method performed by a wireless communication device that performs burst transfer,
A transmission step of transmitting a frame including a sequence number indicating the number of remaining frames for performing burst transfer;
Based on the sequence number included in the received frame, a calculation step for calculating the end timing of the burst transfer according to the sequence number;
When the end timing is reached, it is determined whether or not it is necessary to forcibly end the reception of the burst transfer frame. And a resuming step of forcibly terminating reception and resuming reception of another frame after burst transfer. A program to be executed by a computer of a wireless communication device that performs burst transfer,
A transmission process in which a sequence number indicating the number of remaining frames for burst transfer is included in the frame and transmitted,
Based on the sequence number included in the received frame, a calculation process for calculating the end timing of burst transfer according to the sequence number;
When the end timing is reached, it is determined whether or not it is necessary to forcibly end the reception of the burst transfer frame. A program for forcibly terminating reception and causing the computer to execute resumption processing for resuming reception of another frame after burst transfer.

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