JP5330015B2 - Video transmission terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, when wireless communication of moving image data is performed using a packet, since CTS (occupancy time information) is imparted to each packet, a transmission rate may be reduced and a moving image is not displayed in real time because of a delay time. <P>SOLUTION: An image transmitting apparatus divides one frame of moving image data into a plurality of packets and transmits them to a receiving-side wireless terminal after adding to a head of the first packet one command (occupancy time information) inhibiting transmission from any other wireless terminal before completion of transmission of the final packet. Furthermore, a period of time for vertical synchronism provided in each frame is released to the other wireless terminal as a radio space, the radio space is effectively utilized at high speed and with low delay. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a moving image transmission terminal that transmits a captured moving image to a receiver by wireless communication and displays the captured moving image almost in real time when shooting.

  2. Description of the Related Art Conventionally, the progress of high-speed wireless data communication technology has been remarkable, and wired / wireless LANs that communicate information within a relatively small area have been widely used in personal computers due to the cost reduction of components. Under such circumstances, wireless LANs that do not require laying of communication lines are rapidly adopted and widely recognized because PCs can be moved and used freely.

  IEEE802.11b and IEEE802,11g are widely used as interface standards in this wireless LAN. Both of these IEEE802.11b and IEEE802,11g are wireless communications using the same frequency 2.4 GHz band, IEEE802.11b was developed first, and later, IEEE802.11g with higher speed was developed.

  Among these, IEEE802.11g employs a modulation method different from that of IEEE802.11b in order to perform high-speed communication. A wireless LAN device having only IEEE802.11b that is already distributed in the market cannot receive a new signal of a new IEEE802.11g high-speed modulation scheme. On the other hand, a wireless LAN device used for the later IEEE802.11g is generally configured to be able to transmit and receive IEEE802.11b signals.

  On the other hand, in IEEE802.11b and IEEE802.11g, occupancy time information called NAV (Network Allocation Vector) is added to the head of a packet for notification. The device that has received the message does not transmit to the target receiving device during the occupation time. However, devices that only support IEEE802.11b cannot receive the NAV provided at the beginning of the IEEE802.11g packet due to the difference in the modulation method described above, and this causes unnecessary collisions over the air. Can be considered.

  As a countermeasure, a technique called CTS (Clear to Send) to Self has already been developed before a packet for sending IEEE802.11g data. This CTStoSelf is an IEEE802.11g device that sends a CTS packet of 11b modulation scheme before sending an IEEE802.11g data packet, and the IEEE802.11g that follows the CTS packet in the NAV value included in the CTS. By setting the time required to transmit the 11g packet, the transmission of the IEEE802.11b device is stopped. As a result, it is possible to avoid a collision between an IEEE802.11g device and a device that supports only IEEE802.11b, which cannot recognize an IEEE802.11g signal.

  In addition, when considering a moving image transfer system using a wireless LAN or the like, in applications such as TV broadcasting and movie playback, the delay time due to the wireless system is only for vision, so the overall delay in the image. If this happens, it will not be a serious problem. However, remote operation using the received moving image, for example, when wirelessly transmitting a moving image taken with a camera and operating the device in real time while viewing the moving image display, the actual status of the subject is displayed. In order to eliminate the difference (the difference with time) from the current state of the subject, it is desirable that the delay time is as close to zero as possible.

  In order to shorten such a delay time, for example, it is effective to use a wireless transmission method disclosed in Patent Document 1. In general, when a moving image is compressed in units of frames, the image can be compressed only after one frame is accumulated. However, as disclosed in Patent Document 1, by compressing after dividing one frame of an image. , You can start compression quickly. The delay time can be further shortened by the earlier start. Use of the wireless transmission method disclosed in Patent Document 1 is effective for reducing the delay time.

JP 2005-143668 A

  Normally, when a moving image is compressed in units of frames, it can be compressed only after the image is accumulated for one frame. However, as disclosed in Patent Document 1, by compressing after dividing one frame of an image. , You can start compression quickly. The delay time can be further shortened by the earlier start.

  However, even if the communication speed of wireless transmission is improved due to technological innovation, it is not sufficient for transmitting high-resolution moving images. To transmit moving images wirelessly, transmission is performed per unit time using image compression technology. At present, the amount of data that must be reduced is reduced, and if a moving image is transmitted after compression, the delay time becomes longer.

  Furthermore, in order to transmit a high-resolution moving image, there is a demand for transmitting data at a higher speed by drawing out wireless performance to the limit. In the CTS to Self technique described above, as shown in FIGS. 3A and 3B, CTS is assigned to each packet Pa. Therefore, in high-speed transmission, the occupation time of CTS cannot be ignored and the effective transmission rate is reduced. Is generated. Here, FIG. 3A shows a mode without CTS to Self, and FIG. 3B shows a mode with normal CTS to Self. In addition, as described above, in the transmission of moving images, the current wireless transmission speed is not sufficient, and there is a desire to continue to use the radio without interruption as much as possible. There is also a problem of allowing radio use and effectively utilizing radio wave resources.

  Therefore, an object of the present invention is to provide a moving image transmitting terminal that achieves both of improvement of transmission efficiency (effective transmission rate), effective utilization of radio waves, and reduction of delay time.

  In order to achieve the above object, an embodiment according to the present invention provides a plurality of packets of one frame or one field of moving image every frame time or every field time on a wireless network including a plurality of terminals. A transmission unit that performs predetermined transmission, a setting unit that sets a time for occupying the wireless network to transmit the moving image of the one frame or one field as an occupancy time, and the one frame or one Prior to transmitting a moving image of a field, a moving image transmitting terminal comprising: notification means for notifying a terminal other than the communication target on the wireless network that the wireless network is occupied for the occupied time I will provide a.

  Also, in the moving image transmission terminal according to the embodiment of the present invention, the setting means configures the moving image of one frame or one field on the wireless network from the time when the notification is transmitted to the wireless network. The occupation time is set to a time longer than the time until the start of transmission of the first packet.

Furthermore, according to an embodiment of the present invention, on a wireless network including a plurality of terminals, a moving image of one frame or one field is divided into a plurality of packets every frame time or every field time. A transmission step of transmitting the frame, a setting step of setting a time for occupying the wireless network to transmit the moving image of the one frame or one field as an occupying time, and transmitting the moving image of the one frame or one field Prior to this, there is provided a moving picture transmission method comprising a notification step of notifying a terminal other than a communication target on the wireless network that the wireless network is occupied for the occupied time.

  According to the present invention, it is possible to provide a moving image transmission terminal that achieves both of improvement in transmission efficiency (effective transmission rate), effective utilization of radio waves, and reduction in delay time.

FIG. 1 is a block diagram showing the overall configuration of a communication system including a moving image transmission terminal according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration example of the processing control unit illustrated in FIG. 1. FIG. 3 is a diagram showing image data obtained by the CTS to Self technique. FIG. 4A is a diagram illustrating uncompressed frame unit or field unit image data output from the imaging unit. FIG. 4B is a diagram showing image data compressed by MPEG processing. FIG. 4C shows the received image data. FIG. 4D shows image data displayed after the received image data is expanded. FIG. 5A is a diagram illustrating image data for each frame output from the imaging unit 2. FIG. 5B is a diagram illustrating image data obtained by dividing one frame of image data into packet units and performing image compression. FIG. 5C shows the received image data. FIG. 5D is a diagram showing the image data displayed after the received image data is expanded. FIG. 6 is a diagram illustrating image data on the time axis when wireless communication is performed by dividing an image of one frame using general CTS to Self. FIG. 7 is a diagram showing image data (for one frame) on the time axis when wireless communication is performed by dividing an image into packets in the wireless communication according to the present embodiment. FIG. 8 shows image data on the time axis when an image of one frame is divided into a plurality of packets and wirelessly communicated as the second embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing the overall configuration of a communication system including a moving image transmission terminal according to the first embodiment of the present invention.

  In this communication system, a network composed of a plurality of image transmission apparatuses 1 and a plurality of image receiving apparatuses 11 is constructed, and wireless network communication is performed with an appropriately selected partner (image receiving apparatus 11). In FIG. 1, one image transmitting apparatus 1 and one image receiving apparatus 11 are representatively shown. In the following description, when the number of transmitting devices and receiving devices to be communicated is within a limited number, the same applies to direct communication instead of network communication using a LAN or the like. Further, the image data is in units of one frame and one field, but in the following description, the image data is described in units of one frame. Of course, the present invention can be equally applied to either one frame or one field of image data.

  The image transmission device 1 captures an image by generating an image signal, a signal processing for the image signal, a processing control unit 3 for setting and notifying an occupation time described later, and a compression process for the image data. It comprises a compression unit 4 to be applied, a radio unit (transmission means) 5 that converts image data into a radio wave signal and transmits the radio signal, and an antenna 6 that performs transmission.

  In a detailed configuration, the imaging unit 2 receives a subject lens imaged on a light receiving surface and generates an image signal (analog signal) by photoelectric conversion, and a photographing lens 21 for forming a subject image. (CCD or the like) 22.

  As illustrated in FIG. 2, the processing control unit 3 includes a signal processing unit 23 that digitizes a moving image (image signal) in units of one frame with respect to the image signal input from the imaging unit 2. A memory unit 24 for storing digitized image data in units of frames, a setting unit 25 for setting a time for occupying the wireless network to transmit the image data, and a method for transmitting the image data. First, the wireless unit is configured to transmit to the other terminals other than the communication target (image receiving device 11) on the wireless network together with the output data from the compressing unit 4 for notifying that the wireless network is occupied for the occupied time. And a CPU 26 that gives instructions to 5 and performs calculation and control in the processing control unit 3. The signal processing unit 23 may have a function of performing image processing such as noise removal as necessary. Further, the memory unit 24 stores a vertical synchronization signal period for displaying a moving image on a display unit to which one frame of moving image is transmitted, or a time obtained by subtracting the vertical synchronization signal period from the one frame time.

  The compression unit 4 reads the image data from the memory unit 24 of the processing control unit 3, compresses the image data so as to be within the target transfer rate determined by the limitation of the effective transmission rate of the wireless unit 5, and performs the wireless unit 5. To send. The compression unit 4 is provided according to the design specifications of the system and is not necessarily a necessary component.

  The wireless unit 5 performs digital modulation or the like on image data, divides a frame of moving image into a plurality of packets (or wireless packets) every frame time or every field time, The transmission antenna 6 transmits the signal as a radio signal. The wireless unit 5 also performs wireless communication for function information and wireless network occupation notification on image data.

Next, the image receiving device 11 will be described in detail.
The image receiving device 11 is expanded by an antenna 12 that receives a wireless signal transmitted from the image transmitting device 1, a wireless unit 13 that demodulates the received wireless signal, and a decompressing unit 14 that decompresses compressed image data. The image processing unit 15 performs image processing (including signal conversion) for displaying high-quality image data, and the display unit 16 displays an image. The image processing unit 15 includes a memory 27 for recording image data and application programs in addition to a CPU that performs image processing. Further, the memory 27 stores a vertical synchronization signal period or a time obtained by subtracting the vertical synchronization signal period from one frame time when the received moving image of one frame is displayed on the display unit 16. In this configuration, a radio signal (image data or the like) received by the antenna 12 is input to the radio unit 13. The radio unit 13 demodulates the radio signal to generate image data in units of packets and information related to the image data. Thereafter, the decompression unit 14 restores the compressed image data to the original size of the image data to be decompressed, and writes it in the memory 27 in the image processing unit 15 in units of frames. The image processing unit 15 reads the image data, performs image processing for high-quality display, and displays the image data on the display unit 16 including a liquid crystal panel. At this time, the image processing unit 15 performs a process for making the image easier to see and a process for making the image more visible, and displays the image on the display unit 16 for sending.

Next, a delay time in transmission / reception of image data will be described.
In general, in order to wirelessly transmit moving images without interruption, it is desirable that there is no interruption in wireless transmission. However, as a characteristic of radio, temporary interruption of radio transmission due to external noise, interference, unintentional change of antenna direction in the case of mobile communication is inevitable.

  When a moving image is transferred through a wireless LAN, generally, a moving image is stored in a memory for a certain period of time (generally about 1 to 3 seconds), and then read out to sequentially reproduce the moving image. As a result, even if a short interruption occurs, the reproduced image is not interrupted by continuously reproducing the moving image stored in the memory. However, when this method is used, it is obvious that the delay time increases between the actual state of the subject and the state of the displayed subject.

Another factor for extending the delay time is a delay time related to image compression, which will be described in detail with reference to FIGS. 4 (a) to (d) and FIGS. 5 (a) to (d).
4A to 4D show the delay time and the flow of image data when inter-frame compression is used by MPEG or the like. FIG. 4A is a diagram illustrating uncompressed frame unit or field unit image data output from the imaging unit 2. FIG. 4B is a diagram showing image data compressed by MPEG processing. FIG. 4C shows the received image data. FIG. 4D shows image data displayed after the received image data is expanded.

  In general, for compression of moving images, not the compression processing in units of image frames using JPEG or the like, but the fact that there is little difference in image data between frames as represented by MPEG or the like is used. Therefore, inter-frame compression that obtains a high compression rate is preferred. In MPEG and the like, as shown in FIG. 4B, there is a frame that performs only intra-frame compression called an intra picture, once in 15 frames. Although the overall image data amount can be reduced by this compression, the data amount of the intra picture frame shown at the top of FIG. 4B is smaller than that of the frame using the difference between frames. Will increase. In FIG. 4B, 1_F (frame 1) corresponds to an intra picture. As shown in FIG. 4C, this 1_F requires several times the communication time with respect to other frames when transmission or reception is performed. For this reason, when the received image data is displayed, the processing of 1_F takes time, so that a delay time occurs as shown in FIG. In addition, when performing display, if the playback is not performed at the same vertical synchronization frequency as that of the imaging system, the motion of the screen becomes unnatural and smooth, so all frames after the intra picture frame are equal to the maximum delay time of the intra picture frame. Just need to play later late.

  As described above, when image compression is performed by MPEG, the delay time increases due to variations in the compression ratio between frames more than an increase in pure delay time of compression. In other words, when the captured image is displayed by wireless communication, the situation before the actual delay of the subject is displayed as an image.

Next, a method for dividing and compressing an image of one frame into packet units (Pa) will be described in detail.
FIGS. 5A to 5D are diagrams showing a delay time and a flow of image data generated when image compression is used after packet division for each frame. As an example, a technique disclosed in the invention of claim 1 (claim 2) will be described. Here, FIG. 5A is a diagram illustrating image data for each frame output from the imaging unit 2. FIG. 5B is a diagram illustrating image data obtained by dividing one frame of image data into packet units and performing image compression. FIG. 5C shows the received image data. FIG. 5D is a diagram showing the image data displayed after the received image data is expanded.

  In this example, one frame is divided into seven to perform wireless communication. It can be seen that the delay in each process such as compression, wireless transmission, and decompression is about 1/7 of one frame, and the delay time is sufficiently shorter than one frame.

  From the above description, it can be seen that the communication method in FIG. 4 described above generates a delay longer than at least two frames as compared with the communication method in FIG.

  Further, paying attention to the density of wireless line data transmission, the communication method in FIG. 5 has a blank period of wireless transmission corresponding to the Vsync vertical synchronization period of the CCD or the display system. On the other hand, in the communication method in FIG. 4, the density of wireless data is not synchronized with the frame frequency.

Next, with reference to FIGS. 5 to 7, moving image communication by the moving image transmitting terminal of the present embodiment will be described. In the image data described below, an image is handled in units of one frame. Here, a unit of one frame will be described as an example.
FIG. 6 is a diagram illustrating image data on the time axis when wireless communication is performed by dividing an image of one frame using general CTS to Self. The image data 11g is given a CTS 11b at the head of each packet 11g, and the occupation time by NAV is set. FIG. 6 shows a conventional example for comparison with the present embodiment.

  FIG. 7 shows image data (for one frame) on the time axis when wireless communication is performed by dividing one frame of image into packets in the wireless communication according to the present embodiment. The time required for this wireless communication is set by CTS as NAV (occupation time information). Communication (transmission / reception) of image data is performed within the set occupation time.

  In setting the occupation time, as described above, when the inter-frame correlation such as MPEG is not used, a clear blank period of the wireless packet cannot be set for the vertical synchronization signal. For this reason, the radio space cannot be regularly opened to other radio terminals.

  On the other hand, as shown in FIG. 5, when one frame is divided and then compressed and transmitted as a packet, if the time required to send the packet is sufficiently shorter than the vertical synchronization time, it is clear. It is possible to secure a blank period in simple wireless communication. If this blank period is used, it is possible to open a radio space to other transmitting terminals.

Next, the delay time will be described.
The delay time in the present embodiment is a basic unit time for processing image data for a plurality of basic units divided (a time obtained by adding the time required for compression processing, transmission / reception, and expansion processing). That is, the processing of each divided image data (packet) is started after being accumulated once, so that the accumulation time and the substantial processing time are delayed.

  For example, the data transfer from the compression unit 4 to the wireless unit 5 is started after the compression of the image data for each packet unit is completed. Furthermore, since the image data transmitted from the wireless unit 5 is received in units of packets, the decompression unit 14 starts decompression processing after the data for the packet is accumulated.

  As described above, since the basic unit time required for packet processing is equally delayed between the packets, the number of image divisions is increased and one packet is reduced, so that each processing time is overwritten. It can be seen that the time is shortened. In order to simplify the data structure, it is preferable to set the image division unit to one wireless packet. However, if the size of one packet is made too small in order to shorten the delay time under this condition, the packet is reduced. Since the ratio of the header portion necessary for one-time transmission increases and the wireless transmission efficiency decreases, it is necessary to make a trade-off.

  When the conventional method shown in FIG. 6 is applied to the present embodiment, the total time in which one CTS is assigned to the head side of each packet becomes the occupation time.

  As described above, the conventional method originally enables transmission / reception in a large number of wireless terminals at the same time by assigning a CTS to the head of each packet and setting only the occupation time for the packet. On the other hand, since CTS is not required for each packet, transmission completion in one wireless terminal is delayed. In addition, if another wireless terminal occupies a gap between packets, the transmission completion timing changes, so that it is difficult to predict the delay time.

  On the other hand, since the communication method shown in FIG. 7 in the present embodiment is in the form of a plurality of packets in which image data for one frame is continuous in time series, an image for one frame is included in the leading packet. Since only one CTS in which NAV (occupation time information) is set is given as a command necessary for data transmission, the number of CTSs corresponding to a number obtained by subtracting one from the total number of packets as compared with the conventional method. This eliminates the time required to eliminate interruptions from other wireless terminals in the middle of the frame.

  In the present embodiment, the memory 27 of the image processing unit 15 performs vertical synchronization from the vertical synchronization signal period or one frame time or one field time when the received moving image of one frame or one field is displayed on the display unit 16. The time obtained by subtracting the signal period is stored. Based on the time obtained by subtracting the vertical synchronizing signal period from these vertical synchronizing signal periods or one frame time or one field time, the image processing unit 15 is a time obtained by subtracting the vertical synchronizing signal period from one frame time or one field time. Is set as the occupation time.

  As described above, according to the present embodiment, it is necessary to transmit / receive a packet for one frame or one field at the head of the first packet when transmitting a packet of image data of one frame or one field in a moving image. Transmission of all image data (for one frame or for one field) is possible by adding a single CTS with a long time (occupied time) set as NAV, thus improving transmission efficiency (effective transmission speed) In addition, it is possible to achieve both a short delay time and efficient sharing of the wireless space with other wireless terminals.

  In particular, the communication and processing of one CTS attached to the head of the first packet is completed before the compression processing of the head packet of one frame is completed and the transmission is started, so that the CTS transmission time relationship is determined. The delay time can be made unaffected.

  Therefore, the moving image transmission terminal of the present embodiment can be applied to a device that performs remote operation, for example, an arm operation system of a machine tool, an operation system of a production line in which a plurality of manufacturing apparatuses are connected by a transport mechanism, and the like. it can. By using these systems, there is no difference between the current state of the subject and the state of the displayed subject when operating while looking at the subject (imaging target) displayed on the screen. Therefore, an accurate operation can be performed.

Next, a second embodiment will be described.
FIG. 8 shows image data (one frame) on the time axis when an image of one frame is divided into a plurality of packets and wireless communication is performed in the wireless communication according to the present embodiment.

  In the first embodiment described above, the time required for wireless transmission for one frame is set as the occupation time as the NAV. In the present embodiment, further, a reduction in the occupation time is realized. In other words, if for some reason the occupancy time is set longer than the actual transmission time, or if the transmission of the last packet is completed before the occupancy time, even after the transmission of the last packet is completed If it is within the occupation time, it is a wasteful time during which no communication is performed.

  Usually, in order to prevent communication from being superimposed (interference) at the same frequency, many wireless systems including a wireless LAN are currently in use of the radio frequency used for the transmission before starting the transmission. An operation called carrier sense is performed to intercept whether there is any. If it is being used by another system or wireless terminal, it waits until communication at that frequency is completed.

  In this embodiment, this carrier sense is used. In other words, if transmission of the last packet in the series of packets shown in FIG. 8 is started, even if the time occupied by the NAV has been exceeded, other wireless terminals are not using carrier sense. Until the transmission of the last packet is completed, collision is avoided by waiting for the start of transmission.

  Therefore, the occupation time that must be ensured by the NAV, that is, the minimum time during which transmission from other wireless terminals is prohibited, constitutes one field or one frame from the completion of CTS transmission as shown in FIG. The period until the start of transmission of the last packet to be transmitted. The setting unit 25 sets this period.

  As described above, according to the present embodiment, by ending the occupation time after starting the transmission of the last packet, the transmission of the last packet can be started together with the completion of the transmission of the last packet. The period during which transmission of other wireless terminals is prohibited is minimized. Therefore, according to the present embodiment, when the moving image transmitting terminal is transmitting, it is possible to restrict interference from other wireless terminals to prevent interference and to effectively use the wireless space.

  In the first and second embodiments described above, IEEE802.11b / 11g is described as an example, but it is needless to say that the present invention is not limited thereto. For example, it can be easily applied to a communication system having a function of stopping transmission for a certain period of time using a protocol or a command, and an equivalent effect can be obtained.

  In addition, in the image data, one frame with a progressive frame or one frame with an interlace field is taken as an example. However, the image data is not particularly limited, and may be set as appropriate according to design specifications.

The embodiment described above includes the following inventions.
(1) In a wireless image transmission system in which each frame or field of moving image data generated in synchronization with a certain vertical synchronizing signal is divided into two or more packets and transmitted, each field or frame A radio that transmits a wireless packet including a command for prohibiting wireless transmission of another wireless device that uses the same frequency for a time required to transmit a packet for one frame or one field before transmitting the leading wireless packet Image transmission system.

  (2) The wireless image transmission system according to (1), wherein a time necessary for transmitting wireless packets for one frame or one field is a time obtained by subtracting a vertical synchronization blanking period from a vertical synchronization period.

  (3) The time required for transmitting the wireless packet for one frame or one field is set to one frame from the completion of transmission of a wireless packet including a command for prohibiting wireless transmission of another wireless device using the same frequency. Alternatively, the wireless image transmission system according to (1), wherein a time longer than a time until transmission of the last wireless packet constituting one field is started.

  DESCRIPTION OF SYMBOLS 1 ... Image transmission apparatus, 2 ... Imaging part, 3 ... Processing control part, 4 ... Compression part, 5 ... Radio | wireless part (transmission means), 6 ... Antenna, 11 ... Image receiving apparatus, 12 ... Antenna, 13 ... Radio | wireless part, 14 DESCRIPTION OF SYMBOLS ... Decompression part, 15 ... Image processing part, 16 ... Display part, 21 ... Shooting lens, 22 ... Imaging element, 23 ... Signal processing part, 24 ... Memory part, 25 ... Setting part, 26 ... CPU, 27 ... Memory.

Claims (7)

Transmitting means for dividing a moving image of one frame or one field into a plurality of packets every one frame time or every one field time on a wireless network including a plurality of terminals, and performing predetermined transmission;
Setting means for setting a time for occupying the wireless network to transmit the moving image of one frame or one field as an occupancy time;
Prior to transmitting the moving image of one frame or one field, notifying means for notifying the terminal other than the communication target on the wireless network that the wireless network is occupied for the occupied time;
A moving picture transmitting terminal comprising: The vertical synchronization signal period when the moving image is displayed on the display unit of the transmission destination terminal that transmits the moving image of one frame or one field by the moving image transmission means, or the one frame time or one field time Storage means for storing the time obtained by subtracting the vertical synchronization signal period from
The setting means includes the vertical synchronization signal period from the one frame time or one field time based on the vertical synchronization signal period or a time obtained by subtracting the vertical synchronization signal period from the one frame time or one field time. The moving image transmitting terminal according to claim 1, wherein a time obtained by subtracting is set as the occupied time.   The setting means has a time longer than the time from the time when the notification is completed to be transmitted on the wireless network until the time when the last packet constituting the moving image of one frame or one field is started to be transmitted on the wireless network. The moving picture transmitting terminal according to claim 1, wherein the occupying time is set.   The setting means sets the time from the time when transmission of the notification is completed on the wireless network to the time when transmission of the last packet constituting the moving image of one frame or one field starts on the wireless network. The moving image transmitting terminal according to claim 1, wherein the moving image transmitting terminal is set as follows.   The setting means is configured to end the occupation time after starting transmission of the last packet constituting the moving image of one frame or one field on the wireless network from the time when transmission of the notification is completed on the wireless network. The moving image transmitting terminal according to claim 1, wherein an occupation time is set. A transmission step of performing predetermined transmission by dividing a moving image of one frame or one field into a plurality of packets every one frame time or every one field time on a wireless network including a plurality of terminals;
A setting step of setting a time for occupying the wireless network to transmit the moving image of one frame or one field as an occupancy time;
Prior to transmitting the moving image of one frame or one field, a notification step of notifying the terminal other than the communication target on the wireless network that the wireless network is occupied for the occupied time;
A moving image transmission method comprising: A transmission step of performing predetermined transmission by dividing a moving image of one frame or one field into a plurality of packets every one frame time or every one field time on a wireless network including a plurality of terminals;
A setting step of setting a time for occupying the wireless network to transmit the moving image of one frame or one field as an occupancy time;
Prior to transmitting the moving image of one frame or one field, a notification step of notifying the terminal other than the communication target on the wireless network that the wireless network is occupied for the occupied time;
A video transmission program for executing

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