JPH1063588A - Transmitting access control system for multimedia information - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize a transmission line by making it hard to generate the collision, etc., of information at the time of connecting plural terminal equipments through a common transmission line and transmitting picture information and voice information with plural time attributes through the use of the common transmission line. SOLUTION: In order to transmit multimedia information from a terminal equipment A to a terminal equipment D, a starting message is transmitted to all the terminals, each terminal equipment analyzes the starting message and a terminal equipment to be an arbiter transmits an arbiter arbitration message to the other terminal equipments and becomes the arbiter. An arbiter 10 calculates the transmission timing of each terminal equipment by means of a timing arbitration part 18 based on information sent to the arbiter 10 from each terminal equipment through the transmission line 50 to inform each terminal of the timing through the use of a timing information message, and each terminal equipment transmits picture information and voice information based on obtained timing information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a real-time multimedia information transmission / reception system such as a video conference for handling packet-switched traffic, and more particularly to a transmission / reception system having a mechanism free from collision on a transmission line. The present invention relates to a multimedia information transmission / reception system that can effectively use the bandwidth of a road.

[0002]

2. Description of the Related Art In an information communication system in an office or the like, a local area network (hereinafter, referred to as LAN) is widely used.

FIG. 12 shows a configuration of a conventional packet switching type multimedia information transmitting / receiving system using such a LAN. 12, a terminal device (A) 310 to a terminal device (F) 360 are connected to each other via a transmission line 370, and a terminal device (A) 310 to a terminal device (D) 340 has a camera (A). ) 315, camera (B) 325,
Camera (C) 380 and camera (D) 345 are connected.

[0004] The terminal device (C) 330 includes a channel state detecting unit 338 for determining the presence or absence of data on the transmission path 370 and a transmission data storage unit for storing transmission data of multimedia information.
333, a reception data storage unit 334 for storing the received multimedia information, a transmission unit 331 for transmitting the multimedia information stored in the transmission data storage unit 333, and a reception unit for receiving the multimedia information from the transmission path 370. 332, a decoder unit 335 for decoding the received multimedia information,
It comprises an output unit 336 for displaying the decoded multimedia information on the screen and outputting the audio, and an encoder unit 337 for encoding the multimedia information input from the camera (C) 380. Terminal device (A) 310 to terminal device (D) 340
Has a similar configuration, and transmits and receives information having a time axis such as multimedia information.

[0005] Further, the terminal device (E) 350 includes a channel state detecting section 358 for determining the presence or absence of data on the transmission path 370,
Input section for inputting information such as text to be sent data
355, a transmission data storage unit 353 for storing transmission data,
A reception data storage unit 354 for storing received information, and a transmission unit 351 for transmitting information stored in the transmission data storage unit 353
And a receiving unit 352 for receiving information from the transmission path 370, and an output unit 356 for displaying the received information on the screen and outputting the sound. Terminal device (E) 350 and terminal device (F) 3
60 transmits and receives information having no time axis such as character information.

[0006] The operation of the multimedia information transmitting / receiving system configured as described above will be described below. First, the multimedia information input from the camera (C) 380 is encoded by the encoder unit 337 and stored in the transmission data storage unit 333. If data exists in the transmission data storage unit 333, the channel state detection unit 338 determines whether there is data on the transmission path 370. Here, when there is no data on the transmission path 370, the terminal device (C) 330 outputs the data stored in the transmission data storage unit 333 through the transmission unit 331. Since each terminal device has such a function, for example, the terminal device (A) 310
A video conference or the like is realized between the terminal and the terminal device (B) 320.

On the other hand, a method called circuit switching using a time division multiplexing method is widely used (published by Nikkei BP,
Nikkei Datacom 2 Time Division Multiplexer). In this method, one line is divided every time and a line is fixedly allocated.

[0008] Further, as a commercialized example, there is StarWorks of the United States Starlight. This is because the center device can transmit information having a time axis to each terminal device by allocating the bandwidth of the transmission path when transmitting the video information stored in the center device.

[0009]

However, in the configuration using the conventional packet switching method, as shown in FIG. 13, at time T1, the terminal device (E) 350
Is being transmitted, the channel state detection unit 338 of the terminal device (A) 310 transmits the multimedia information data 411 to be transmitted to the terminal device (A) 310 in order to detect that the transmission line 370 is occupied. Cannot be sent. When the transmission of such multimedia information fails, for example, it is necessary to wait until the transmission path 370 is in an empty state before transmitting. Therefore, when a terminal device that transmits and receives multimedia information having a time axis and a terminal device that transmits and receives information without a time axis coexist on the transmission path 370, or only a terminal device that transmits and receives multimedia information is used. When configured, there is a problem that transmission and reception of multimedia information having a time axis are delayed.

[0010] In addition, in the configuration based on the circuit switching system, in order to identify an assigned terminal, information including an identifier must be transmitted without fail. The point that transmission is impossible is the overhead of the bandwidth of the transmission path.

On the other hand, the method of polling from the center device to each terminal device has a problem that it is difficult to control the transmission time from each terminal device and it is impossible to allocate a band.

[0012] Further, in the example of StarWorks of Starlight, transmission is limited to transmission from the center device, and transmission line allocation for transmission from the terminal device is impossible.
Video conferences with two-way communication cannot be realized.

The present invention solves the above-mentioned conventional problems, and has a mechanism for preventing occurrence of a collision on a transmission line when handling multimedia information having real-time properties such as a video conference. It is an object of the present invention to provide a multimedia information transmission access control method capable of effectively utilizing a path band.

[0014]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a multimedia system in which a plurality of terminal devices are connected by a transmission line to realize mutual communication between the terminal devices. In an information transmitting and receiving system, means for dynamically giving a terminal device a representative right by arbitration between respective terminal devices, and an arbiter which is a terminal device having a representative right,
Means for calculating timing information for arbitrating the timing of transmitting multimedia information; means for notifying the terminal device of the timing information; and means for transmitting the multimedia information based on the timing information when each terminal device transmits the multimedia information. Means for transmitting to a transmission path.

According to a second aspect of the present invention, in addition to the first aspect, the terminal device includes means for notifying an arbiter of a band required for transmitting multimedia information in advance. It is.

According to another aspect of the present invention, there is provided a multimedia information transmitting / receiving system for connecting a plurality of terminal devices via a transmission line to realize mutual communication between the terminal devices. Means for dynamically giving the terminal device the representation right by arbitration between the respective terminal devices,
An arbiter, which is a terminal device having a representation right, for calculating trigger information for arbitrating the timing of transmitting multimedia information of each terminal device, a means for notifying the terminal device of the trigger information, Means for transmitting the multimedia information to the transmission path based on the trigger information when transmitting the multimedia information.

According to a fourth aspect of the present invention, in addition to the third aspect of the present invention, the terminal device further comprises means for notifying an arbiter of a band required for transmitting multimedia information in advance. It is.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
1 shows a schematic configuration of a multimedia information transmitting / receiving system according to the embodiment. In FIG. 1, a terminal device (A) 10, a terminal device (B) 20, a terminal device (C) 30, a terminal device (D) 40, a terminal device (E) 70, and a terminal device (F)
90 are connected to each other via a transmission line 50, and the terminal device (A) 10 to the terminal device (D) 40 include a camera (A) 60,
Camera (B) 25, Camera (C) 80 and Camera (D) 45
Is connected.

The terminal device (A) 10 includes a transmitting unit 11 for realizing an output from the terminal device (A) 10 and a use state on the transmission path 50, and determines a transmission timing of data having no time attribute. A channel state detection unit 42 for determining, a reception unit 12 for receiving information from the transmission path 50, a transmission data storage unit 13 for storing encoded data for transmission, and a reception data storage for storing received data. Unit 14, a decoder unit 15 for decoding the received encoded multimedia information, an output unit 16 for outputting the decoded multimedia information, and a camera (A) connected to capture the multimedia information An encoder unit 17 that encodes the multimedia information input through 60, a timing arbitration unit 18 that determines the transmission timing of the terminal device connected to the transmission path 50,
An arbitration unit 19 for determining an arbiter having an arbitration right from the terminal devices (A) 10 to (D) 40.

The terminal device (C) 30 includes a transmitting unit 31 for realizing an output from the terminal device (C) 30, a channel state detecting unit 48 for determining a transmission timing of data having no time attribute, Receiver 32 for receiving information from transmission line 50
A transmission data storage unit 33 for storing encoded data for transmission, a reception data storage unit 34 for storing received data, and a decoder unit 35 for decoding received encoded multimedia information. An output unit 36 for outputting the decoded multimedia information; and an encoder unit for encoding the multimedia information input through a camera (C) 80 connected to capture the multimedia information.
37, a timing arbitration unit 38 for determining the transmission timing of the terminal device connected to the transmission line 50, and the terminal devices (A) 10 to
An arbitration unit 39 for determining an arbiter having an arbitration right from among the terminal devices (D) 40. The terminal device (B) 20 and the terminal device (D) 40 have the same configuration as the terminal device (C) 30.

Further, the terminal device (E) 70 transmits a data from the terminal device (E) 70, a transmitting unit 71 for realizing an output from the terminal device (E) 70, a receiving unit 72 for receiving information from the transmission line 50, and the input data. A transmission data storage unit 73 for storing the received data, a reception data storage unit 74 for storing the received data, and a channel state for observing the use state on the transmission path 50 and determining the transmission timing of the data having no time attribute. It comprises a detection section 75, an output section 76 for outputting received data, and an input section 77 for inputting information such as text. The terminal device (F) 90 has the same configuration as the terminal device (E) 70. The terminal devices (A) 10 to (D) 40 have a function of transmitting and receiving multimedia information having a time attribute, while the terminal device (E) 70 and the terminal device (F) 90 It has a function to send and receive information without attributes.

FIG. 2 shows the relationship between the time and the transmitting terminal for data on the transmission line of the multimedia information transmitting / receiving system, with the horizontal axis representing time and the vertical axis representing the transmitting device. The data 101 on the transmission path is transmitted from the terminal device (C) 30 at time T1, and occupies the transmission path for the time Tex.

FIG. 3 shows messages used for communication between each terminal device and the arbiter. Before the terminal starts transmitting multimedia information, it transmits a start message (a). The start message (a) includes a control code 150 indicating a start message, a terminal identifier 151 for identifying a terminal transmitting the multimedia information, and a start identifier 152 indicating a start message.

The arbiter arbitration message (b) has a control code 181 indicating that it is an arbiter arbitration message.
And a terminal identifier 182 indicating the arbiter. The end message (c) includes a control code 160 indicating that the message is an end message, a terminal identifier 161 for identifying a terminal transmitting the multimedia information, and an end identifier 162 indicating that the message is an end message. .

The timing information message (d) is a control code 170 indicating that it is a timing information message transmitted from the arbiter to each terminal device, and the terminal identifier 17
1, 173, 175, and the transmission timing of the terminal device indicated by these terminal identifiers, the relative time 172, 174, 176 from the timing information message, and the transmission time 177 that each terminal transmits to the transmission path respectively. You.

The operation of the multimedia information transmitting / receiving system of the first embodiment configured as described above will be described below.

First, from the situation where no multimedia information is transmitted and received between the terminal devices, the terminal devices (A) 10, the terminal device (B) 20, the terminal device (C) 30, and the terminal device (D) After the arbiter (the terminal device (A) in this example) is selected from the 40 and a terminal device other than the arbiter makes a request to the arbiter to acquire the right to provide a service, the arbiter determines the transmission timing of the terminal device. A process flow from arbitrating the timing information to receiving the timing information by the terminal device (B) 20, the terminal device (C) 30, and the terminal device (D) 40 will be described.

In FIG. 2, when the terminal devices (A) 10 to (D) 40 try to transmit multimedia information,
It is assumed that start messages 99 to 102 have been transmitted to all terminals. The terminal device name (here, A
To D), a small ASCII code is used as the arbiter. The start message transmitted from each terminal device is analyzed by each terminal device. For example, the terminal device (B) does not transmit the arbiter arbitration message because it receives the start message 99 from the terminal device (A) and determines that the terminal device (A) can be the arbiter.

The terminal device (A) receives the start messages 100 to 102 of the terminal device (D) from the terminal device (B), and the terminal device (A) itself receives the arbiter (hereinafter, the terminal device (A) is referred to as the arbiter). Therefore, the terminal number of the terminal device (A) is inserted into the arbiter arbitration message (b), and the arbiter arbitration message 103 is transmitted to all terminals. The terminal device (B) to the terminal device (D) recognize from the arbiter arbitration message 103 that the terminal device (A) is the arbiter.

The arbiter 10 has a time interval Tbet that can be transmitted by the terminal device based on the number of terminal devices to which the service is to be provided, a arbiter 10 and a reference time of each terminal device.
The relative times Ta, Tb, Tc, Td, and Teno from Ts are calculated in the timing arbitration unit 18 in FIG. Here, the reference time Ts is a time when the reception of the timing information message from the arbiter is completed. Also, from Tbet (Teno-Ta)
Is the band not allocated to each terminal device,
It is used as a band for exchanging information having no time axis such as the end message (c). The arbiter 10 uses the timing information message (d) shown in FIG. 3 to determine whether the channel state detection unit 42 detects an empty transmission path 50, using the terminal device (B) 20, the terminal device (C) 30, and the terminal device (C). (D) 40 is the timing information message (d) 122 of FIG.
Notify.

The terminal device (C) 30 stores the received timing information message (d) in the reception data storage unit 34. When the received data storage unit 34 determines that the received data is the timing information message (d) with reference to the control code 170 of the timing information message (d) in FIG. The transmission time 177 is extracted and transferred to the timing arbitration unit 38. When the timing arbitration unit 38 receives the relative time 174 and the transmission time 177, it resets the counter and starts measuring time. When the terminal device (C) 30 counts the relative time 174, the terminal device (C) 30 activates data transmission to the transmission unit 31 and resets the counter. The transmission unit 31 extracts the data from the transmission data storage unit 33 and transmits the data 106 for the transmission time 177. After that, time is measured and when the count value matches the relative time,
Send data.

Similarly, the terminal device (B) 20 and the terminal device (D) 40 correspond to the terminal identifier 171 and the terminal identifier 175 in the timing information message (d) of FIG.
And extract the relative time 176 and the transmission time 177 to obtain the data 10
5 and data 107 are transmitted. After this, the arbiter
10. The terminal device (B) 20, the terminal device (C) 30, and the terminal device (D) 40 transmit data 108, 109, 110, and 111 by counting the relative time from the arbiter 10. This is because also in the arbiter 10, the timing arbitration unit 18 controls transmission.

Next, an operation in the case where the terminal device (E) 70 and the terminal device (F) 90 that transmit and receive data having no time axis share a transmission path will be described. Terminal device (E) 70
Receives data input from the input unit 77, and
When the data is stored in 73, the channel state detection unit 75 waits until the transmission path 50 becomes unused. When detecting the unused state, the channel state detection unit 75 controls the transmission unit 71,
The data 120 and 121 shown in FIG.

Next, an operation when the terminal device (D) 40 ends transmission in such a six-party communication will be described. When the terminal device (D) 40 completes the transmission, after detecting the vacancy of the transmission path 50, the terminal device (D) 40 shown in FIG.
Is transmitted to the arbiter 10. The arbiter 10 that has received the end message (c) sends the relative time Ta ′, Tb ′, Tc ′,
And Teno 'and the time interval Tbet' are calculated. The arbiter 10 uses the timing information message (d) of FIG. 3 to notify the terminal device (B) 20 and the terminal device (C) 30 of the updated relative time and transmission time using the data 113 of FIG. Using the updated relative time, the arbiter 10, the terminal device (B) 20, and the terminal device (C) 30 transmit data 114, 115, 116, 117, 118, and 119 at determined timing.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
An embodiment will be described. FIG. 4 shows a schematic configuration of a multimedia information transmitting / receiving system according to the second embodiment of the present invention. In FIG. 4, a terminal device (A) 10, a terminal device (B) 20, a terminal device (C) 30, a terminal device (D) 40, a terminal device (E) 70, and a terminal device (F)
90 are connected to each other via a transmission line 50, and the terminal device (A) 10 to the terminal device (D) 40 include a camera (A) 60,
Camera (B) 25, Camera (C) 80 and Camera (D) 45
Is connected.

The terminal device (A) 10 has a transmitting unit 11 for realizing an output from the terminal device (A) 10 and observes a use state on the transmission path 50, and determines a transmission timing of data having no time attribute. A channel state detection unit 42 for determining, a reception unit 12 for receiving information from the transmission path 50, a transmission data storage unit 13 for storing encoded data for transmission, and a reception data storage for storing received data. Unit 14, a decoder unit 15 for decoding the received encoded multimedia information, an output unit 16 for outputting the decoded multimedia information, and a camera (A) connected to capture the multimedia information An encoder unit 17 that encodes the multimedia information input through 60, a timing arbitration unit 18 that determines the transmission timing of the terminal device connected to the transmission path 50,
An arbitration unit 19 for determining an arbiter having an arbitration right from the terminal devices (A) 10 to (D) 40.

The terminal device (C) 30 includes a transmitting unit 31 for realizing an output from the terminal device (C) 30, a channel state detecting unit 48 for determining a transmission timing of data having no time attribute, Receiver 32 for receiving information from transmission line 50
A transmission data storage unit 33 for storing encoded data for transmission, a reception data storage unit 34 for storing received data, and a decoder unit 35 for decoding received encoded multimedia information. An output unit 36 for outputting the decoded multimedia information; and an encoder unit for encoding the multimedia information input through a camera (C) 80 connected to capture the multimedia information.
37, a timing arbitration unit 38 for determining the transmission timing of the terminal device connected to the transmission line 50, and the terminal devices (A) 10 to
An arbitration unit 39 for determining an arbiter having an arbitration right from among the terminal devices (D) 40. The terminal device (B) 20 and the terminal device (D) 40 have the same configuration as the terminal device (C) 30.

Further, the terminal device (E) 70 transmits a signal from the terminal device (E) 70, a transmitting unit 71 for realizing an output from the terminal device (E) 70, a receiving unit 72 for receiving information from the transmission line 50, and transmits the input data. A transmission data storage unit 73 for storing the received data, a reception data storage unit 74 for storing the received data, and a channel state for observing the use state on the transmission path 50 and determining the transmission timing of the data having no time attribute. It comprises a detection section 75, an output section 76 for outputting received data, and an input section 77 for inputting information such as text. The terminal device (F) 90 has the same configuration as the terminal device (E) 70. The terminal devices (A) 10 to (D) 40 have a function of transmitting and receiving multimedia information having a time attribute, while the terminal device (E) 70 and the terminal device (F) 90 It has a function to send and receive information without attributes.

The above is the same as the configuration of FIG. The difference from the configuration in FIG. 1 is that the center device (A) 10 has an encoding control unit 41 and a decoding control unit 43, and the terminal device (B) 20, the terminal device (C) 30, and the terminal device (D) 40 have This is the point that the decoding control unit 44 and the decoding control unit 46 are provided.

FIG. 5 shows the relationship between the time and the transmitting terminal for data on the transmission path of the multimedia information transmitting / receiving system, with the horizontal axis representing time and the vertical axis representing the transmitting device.

FIG. 6 shows a structure of a message from the terminal device in the present embodiment. 6, a start message (aa) includes a control code 150, a terminal identifier 151,
It has a start identifier 152, and this configuration is similar to the configuration of FIG. The difference from the configuration of FIG. 3 is that a necessary band 153 is provided in the start message.

The change message (ab) includes a control code 155 indicating a change message, a terminal identifier 156 for identifying a terminal transmitting the multimedia information, and a change identifier 157 indicating a change message. And a required band 158 for designating a band. The arbiter arbitration message (b) includes a control code 155 indicating that the message is an arbiter arbitration message, and a terminal identifier 156 indicating the arbiter. End message (c)
Is a control code 160, a terminal identifier 161, an end identifier 16
Consists of two. The above configuration is the same as the configuration in FIG. The timing information message (d) is a control code
170, terminal identifiers 171, 173, 175, and relative times 172, 17
4, 176 and transmission times 185, 186, 187.

The operation of the multimedia information transmitting / receiving system of the second embodiment configured as described above will be described below.

First, from the situation that no multimedia information is transmitted and received between the terminal devices, the terminal device (A) 10, the terminal device (B) 20, the terminal device (C) 30, and the terminal device (D) After the arbiter (the terminal device (A) in this example) is selected from the 40 and a terminal device other than the arbiter makes a request to the arbiter to acquire the right to provide a service, the arbiter determines the transmission timing of the terminal device. A process flow from arbitrating the timing information to receiving the timing information by the terminal device (B) 20, the terminal device (C) 30, and the terminal device (D) 40 will be described.

The difference from the multimedia information transmitting / receiving system of the first embodiment is that a band on a transmission path required by each terminal device is specified in a start message transmitted by the terminal device. In FIG. 5, the terminal device (D) 40 attempts to transmit multimedia information from the terminal device (A) 10 and transmits start messages 199 to 202 to the required band 15 in FIG.
Suppose that 3 is specified and sent to all terminals. The same arbiter determination method as described in the first embodiment is used.

Therefore, the terminal device (A) (hereinafter referred to as an arbiter) 10 is connected from the terminal device (B) 20 to the terminal device (D).
Since the terminal device (A) receives the start message of 40 and determines that the terminal device (A) itself becomes the arbiter, the terminal number of the terminal device (A) is inserted into the arbiter arbitration message 203 and the arbiter arbitration message 203 is transmitted to all terminals. . The terminal device (D) 40 to the terminal device (D) 40 recognize that the terminal device (A) 10 is the arbiter from the arbiter arbitration message 203.

The arbiter 10 includes a time interval Tbet that can be transmitted by the terminal device from the number of terminal devices to which the service is to be provided and the required bandwidth declared by the terminal device, a reference time Ts of the arbiter 10 and each terminal device. Relative time from Ta,
Tb, Tc, Td and Teno are calculated in the timing arbitration unit 18 of FIG. Here, the reference time Ts is a time when the reception of the timing information message from the arbiter is completed. Further, a value obtained by subtracting (Teno-Ta) from Tbet is a termination message (c) as a band not allocated to each terminal device.
It is used as a bandwidth for exchanging information that does not have a time axis.

The arbiter 10 uses the timing information message (d) shown in FIG. 6 to determine whether the channel state detector 42 detects that the transmission path 50 is empty, using the terminal device (B) 20 and the terminal device (C) 30. Then, the terminal device (D) 40 is notified of the timing information message (d) 222 of FIG. The required bandwidth specified by the terminal device is reflected in the transmission time of the timing information message (d) 222.

The terminal device (C) 30 stores the received timing information message (d) 222 in the received data storage unit 34. When the received data storage unit 34 determines that the received data is the timing information message (d) with reference to the control code 170 of the timing information message (d) in FIG. And the transmission time 186 are extracted and transferred to the timing arbitration unit 38.

In the timing arbitration unit 38, the relative time 17
When 4 and the transmission time 186 are received, the counter is reset and time measurement is started. When the terminal device (C) 30 counts the relative time 174, the terminal device (C) 30 activates data transmission to the transmission unit 31 and resets the counter.

The transmitting section 31 takes out the data from the transmission data storage section 33 and transmits the data 206 for the transmission time 186. Thereafter, time is measured for periodic data transmission, and when the count value matches the relative time, the data is transmitted.

Similarly, the terminal device (B) 20 and the terminal device (D) 40 have the terminal identifier 171 and the terminal identifier 175 in the timing information message (d) of FIG.
The transmission time 185 and the relative time 176 and the transmission time 187 are extracted, and the data 205 and the data 207 are transmitted. Thereafter, the arbiter 10, the terminal device (B) 20, and the terminal device (C)
The terminal 30 and the terminal device (D) 40 transmit the data 208, 209, 210, 211 by counting the relative time. This is because also in the arbiter 10, the timing arbitration unit 18 controls transmission.

The operation when the terminal device (E) 70 and the terminal device (F) 90 for transmitting and receiving data having no time axis share the transmission line 50 is the same as that described in the first embodiment. The same is true.

Next, an operation when the terminal device (D) 40 terminates transmission in such a six-party communication will be described. When the terminal device (D) 40 completes the transmission, after detecting the vacancy of the transmission line 50, the terminal device (D) 40 shown in FIG.
Is transmitted to the arbiter 10. The arbiter 10 that has received the end message (c) receives the relative time Ta ′, Tb ′, Tc ′,
And Teno 'and the time interval Tbet' are calculated. The arbiter 10 notifies the terminal device (B) 20 and the terminal device (C) 30 of the updated relative time and transmission time using the timing information message (d) of FIG. 6 indicated by the data 213 of FIG. Using the updated relative time, arbiter 10,
The terminal device (B) 20 and the terminal device (C) 30 transmit data 214, 215, 216, 217, 218, and 219 at a determined timing.

Further, by using the change message (ab) instead of the end message (c), when the required bandwidth of the terminal device changes, the terminal device reports to the arbiter and sets the relative time and the transmission time to the timing information message (d). Can be updated.

As described above, according to the second embodiment, by changing the band to be used in accordance with the multimedia information transmitted by the terminal device and notifying the center device, the timing information corresponding to the change can also be obtained. Since the communication is performed with the band, the band on the transmission path can be used effectively.

(Third Embodiment) Next, the third embodiment of the present invention will be described.
An embodiment will be described. FIG. 7 shows a schematic configuration of a multimedia information transmitting / receiving system according to the third embodiment of the present invention. In FIG. 7, a terminal device (A) 10, a terminal device (B) 20, a terminal device (C) 30, a terminal device (D) 40, a terminal device (E) 70, and a terminal device (F)
90 are connected to each other via a transmission line 50, and the terminal device (A) 10 to the terminal device (D) 40 include a camera (A) 60,
Camera (B) 25, Camera (C) 80 and Camera (D) 45
Is connected.

The terminal device (A) 10 has a transmitting unit 11 for realizing an output from the terminal device (A) 10, observes a use state on the transmission line 50, and determines a transmission timing of data having no time attribute. A channel state detection unit 42 for determining, a reception unit 12 for receiving information from the transmission path 50, a transmission data storage unit 13 for storing encoded data for transmission, and a reception data storage for storing received data. Unit 14, a decoder unit 15 for decoding the received encoded multimedia information, an output unit 16 for outputting the decoded multimedia information, and a camera (A) connected to capture the multimedia information An encoder unit 17 that encodes the multimedia information input through 60, a timing arbitration unit 18 that determines the transmission timing of the terminal device connected to the transmission path 50,
An arbitration unit 19 for determining an arbiter having an arbitration right from the terminal devices (A) 10 to (D) 40.

The terminal device (C) 30 includes a transmitting unit 31 for realizing an output from the terminal device (C) 30, a channel state detecting unit 48 for determining a transmission timing of data having no time attribute, Receiver 32 for receiving information from transmission line 50
A transmission data storage unit 33 for storing encoded data for transmission, a reception data storage unit 34 for storing received data, and a decoder unit 35 for decoding received encoded multimedia information. An output unit 36 for outputting the decoded multimedia information; and an encoder unit for encoding the multimedia information input through a camera (C) 80 connected to capture the multimedia information.
37, a timing arbitration unit 38 for determining the transmission timing of the terminal device connected to the transmission line 50, and the terminal devices (A) 10 to
An arbitration unit 39 for determining an arbiter having an arbitration right from among the terminal devices (D) 40. The terminal device (B) 20 and the terminal device (D) 40 have the same configuration as the terminal device (C) 30.

Further, the terminal device (E) 70 transmits the input data, the transmitting unit 71 for realizing the output from the terminal device (E) 70, the receiving unit 72 for receiving the information from the transmission path 50. A transmission data storage unit 73 for storing the received data, a reception data storage unit 74 for storing the received data, and a channel state for observing the use state on the transmission path 50 and determining the transmission timing of the data having no time attribute. It comprises a detection section 75, an output section 76 for outputting received data, and an input section 77 for inputting information such as text. The terminal device (F) 90 has the same configuration as the terminal device (E) 70. The terminal devices (A) 10 to (D) 40 have a function of transmitting and receiving multimedia information having a time attribute, while the terminal device (E) 70 and the terminal device (F) 90 It has a function to send and receive information without attributes.

The above is the same as the configuration of FIG. The difference from the configuration of FIG. 1 is that the terminal device (A) 10 has a trigger generation unit.
51, a terminal device (B) 20, a terminal device (C) 30, and a terminal device (D) 40 provided with a trigger generator 56.

FIG. 8 shows the relationship between the time and the transmitting terminal for data on the transmission line of the multimedia information transmitting / receiving system, with the horizontal axis representing time and the vertical axis representing the transmitting device.

FIG. 9 shows the structure of a message from a terminal device according to the third embodiment. In FIG. 9, the start message (a) includes a control code 150 and a terminal identifier 151.
And a start identifier 152. The arbiter arbitration message (b) includes a control code 181 indicating an arbiter arbitration message and a terminal identifier 182 indicating an arbiter.
It consists of. The end message (c) is the control code 16
0, a terminal identifier 161, and an end identifier 162. The above configuration is the same as the configuration in FIG. The difference from the configuration of FIG. 3 is that, instead of the timing information message,
The trigger information message (d) is exchanged. The trigger information message (d) includes a control code 170, terminal identifiers 171, 173, and 175, and the number of triggers 191, 192, and 193.
And a transmission time 177.

The operation of the multimedia information transmitting / receiving system according to the third embodiment configured as described above will be described below. The difference from the multimedia information transmitting and receiving systems of the first and second embodiments is that the transmission timing of each terminal device is designated as a trigger signal by an arbiter every time.

First, from the situation where no multimedia information is transmitted / received between the terminal devices, the terminal devices (A) 10, the terminal device (B) 20, the terminal device (C) 30, and the terminal device (D) After the arbiter (the terminal device (A) in this example) is selected from the 40 and a terminal device other than the arbiter makes a request to the arbiter to acquire the right to provide a service, the arbiter determines the transmission timing of the terminal device. Arbitration of the trigger information, and the terminal device (B) 2
The process flow until the terminal device (C) 30 and the terminal device (D) 40 receive the trigger information message will be described.

In FIG. 8, it is assumed that the terminal device (A) 10 transmits terminal information (D) 40 to all terminals in an attempt to transmit multimedia information. The same arbiter determination method as described in the first embodiment is used. Therefore, the terminal device (A) (hereinafter referred to as arbiter) 10
Receives the start message of the terminal device (D) 40 from the terminal device (B) 20 and determines that the terminal device (A) itself becomes the arbiter. Therefore, the terminal number of the terminal device (A) is inserted into the arbiter arbitration message 103. Then, an arbiter arbitration message 103 is transmitted to all terminals.

The terminal device (B) 20 to the terminal device (D) 40 recognize from the arbiter arbitration message 103 that the terminal device (A) (hereinafter, referred to as arbiter) is an arbiter. The arbiter 10 has a time interval Tbet that the terminal device can transmit from the number of terminal devices that want to provide the service, and a relative time Ta, Tb, Tc, Td from the arbiter 10 and the reference time Ts of each terminal device. Teno is calculated in the timing arbitration unit 18 of FIG. Here, the reference time Ts is a time when the reception of the trigger information message from the arbiter is completed.

The value obtained by subtracting (Teno-Ta) from Tbet is used as a band not allocated to each terminal device, and as a band for exchanging information having no time axis such as the end message (c). The arbiter 10 uses the trigger information message (d) shown in FIG.
0, the terminal device (C) 30 and the terminal device (D) 40 are notified of the trigger information data (d) 125 of FIG. Furthermore, Ta, T
At the timing determined by b, Tc, Td, Tbet, and Teno, the arbiter 10 activates a trigger to secure the transmission right of each terminal on the transmission path as shown in FIG.

At this time, the duration of the trigger signal 223 for establishing the transmission right of the arbiter 10 is longer than the duration of the trigger signals 224, 225, and 226 for establishing the transmission right of each terminal device. It can be determined as a reference trigger signal, and by counting the number of occurrences of the trigger signal from this reference trigger signal, it is possible to know the transmission timing of the own terminal device.

The terminal device (C) 30 stores the received trigger information message (d) in the received data storage unit 34. In the received data storage unit 34, when it is determined that the received data is the trigger information message (d) with reference to the control code 170 of the trigger information message (d) in FIG. The transmission time 177 is extracted and transferred to the trigger generator 56. The trigger generator 56 resets the counter with a reference trigger signal from the arbiter 10, and counts subsequent trigger signals.

When the terminal device (C) 30 counts the number of times of trigger 192, the terminal device (C) 30 activates the transmission unit 31 for data transmission.
The transmission unit 31 extracts data from the transmission data storage unit 33 and transmits data 106 upon receiving a data transmission instruction from the trigger generation unit 56. After transmitting the multimedia information, the count value is reset each time a reference trigger signal is received. Thereafter, the trigger signal is counted, and when the count value matches the number of triggers, data is transmitted.

Similarly, the terminal device (B) 20 and the terminal device (D) 40 determine the terminal identifier 171 and the terminal identifier 175 in the trigger information message (d) of FIG. Extract transmission time 177 and data 10
5 and data 107 are transmitted. After this, the arbiter
10, the terminal device (B) 20, the terminal device (C) 30, and the terminal device (D) 40, based on the number of triggers and the transmission time,
The data 108, 109, 110, and 111 are transmitted. This is because, also in the arbiter 10, the trigger generator 51 controls the transmission based on the reference trigger signal.

Next, the terminal device (E) 70 and the terminal device (F) 90 for transmitting and receiving data having no time axis are connected to the transmission line 50.
The operation when sharing is described. Terminal device (E)
When the data is input from the input unit 77 and the data is stored in the transmission data storage unit 73, the channel state detection unit 75 waits until the transmission path 50 becomes unused. When detecting the unused state, the channel state detection unit 75 controls the transmission unit 71 to transmit the data 120 in FIG. When the terminal device (E) 70 attempts to continue transmission beyond the time T2, a reference trigger signal is transmitted from the center device (A) 10. Here, the terminal device (E) 70 includes a channel state detection unit.
At 75, a collision is detected on the transmission line 50, and the terminal device (E)
The transmission of 70 data is immediately stopped.

Channel state detector 75 of terminal device (E) 70
Monitors the status of use of the transmission path 50, and transmits data 121 when the transmission path 50 becomes unused. As described above, the trigger signal not only notifies the transmission timing of the terminal device but also secures the transmission path from transmission data having no time axis on the transmission path.

Next, an operation when the terminal device (C) 30 terminates transmission in such a six-party communication will be described. When the terminal device (C) 30 ends the transmission, FIG.
9 is transmitted to the arbiter 10 after detecting that the transmission path 50 is empty. The center device (A) 10 that has received the end message (c)
In the timing arbitration unit 18, the relative times Ta 'and T in FIG.
Calculate b ', Tc' and Teno 'and time interval Tbet'.
The arbiter 10 uses the trigger information message (d) in FIG. 9 to notify the terminal device (B) 20 and the terminal device (D) 40 of the updated number of triggers and transmission time using the data 113 in FIG. Using the updated trigger count and transmission time, the arbiter 10, the terminal device (B) 20, and the terminal device (D) 40 transmit the data 114, 115,
116, 117, 118 and 119 are transmitted.

(Fourth Embodiment) Finally, a fourth embodiment of the present invention will be described. FIG. 10 shows a schematic configuration of a multimedia information transmitting / receiving system according to the fourth embodiment of the present invention. In FIG. 10, a terminal device (A) 10, a terminal device (B) 20, a terminal device (C) 30, a terminal device (D) 40, a terminal device (E) 70, and a terminal device (F) 90 Are connected to each other through
A camera (A) 60, a camera (B) 25, a camera (C) 80, and a camera (D) 45 are connected to the terminal devices (A) 10 to (D) 40.

The terminal device (A) 10 has a transmitting unit 11 for realizing an output from the terminal device (A) 10, observes a use state on the transmission line 50, and determines a transmission timing of data having no time attribute. A channel state detection unit 42 for determining, a reception unit 12 for receiving information from the transmission path 50, a transmission data storage unit 13 for storing encoded data for transmission, and a reception data storage for storing received data. Unit 14, a decoder unit 15 for decoding the received encoded multimedia information, an output unit 16 for outputting the decoded multimedia information, and a camera (A) connected to capture the multimedia information An encoder unit 17 that encodes the multimedia information input through 60, a timing arbitration unit 18 that determines the transmission timing of the terminal device connected to the transmission path 50,
An arbitration unit 19 for determining an arbiter having an arbitration right from the terminal devices (A) 10 to (D) 40;
The terminal device can be triggered at a timing determined by Tb, Tc, Td, Tbet, and Teno, and the trigger signal is counted from a reference trigger signal as a starting point. And a trigger generating unit 51 for starting transmission.

Further, the terminal device (C) 30 includes a transmitting unit 31 for realizing an output from the terminal device (C) 30, a channel state detecting unit 48 for determining a transmission timing of data having no time attribute, Receiver 32 for receiving information from transmission line 50
A transmission data storage unit 33 for storing encoded data for transmission, a reception data storage unit 34 for storing received data, and a decoder unit 35 for decoding received encoded multimedia information. An output unit 36 for outputting the decoded multimedia information; and an encoder unit for encoding the multimedia information input through a camera (C) 80 connected to capture the multimedia information.
37, a timing arbitration unit 38 that determines the transmission timing of the terminal device connected to the transmission path 50, and counts a trigger signal starting from a reference trigger signal. You can call
And a trigger generator 56 that can trigger the terminal device at a timing determined by Ta, Tb, Tc, Td, Tbet, and Teno. The terminal device (B) 20 and the terminal device (D) 40 have the same configuration as the terminal device (C) 30.

Further, the terminal device (E) 70 transmits a data from the terminal device (E) 70, a transmitting unit 71 for realizing an output from the terminal device (E) 70, a receiving unit 72 for receiving information from the transmission path 50, and transmits the input data. A transmission data storage unit 73 for storing the received data, a reception data storage unit 74 for storing the received data, and a channel state for observing the use state on the transmission path 50 and determining the transmission timing of the data having no time attribute. It comprises a detection section 75, an output section 76 for outputting received data, and an input section 77 for inputting information such as text. The terminal device (F) 90 has the same configuration as the terminal device (E) 70. The terminal devices (A) 10 to (D) 40 have a function of transmitting and receiving multimedia information having a time attribute, while the terminal device (E) 70 and the terminal device (F) 90 It has a function to send and receive information without attributes.

The above is the same as the configuration of FIG. The difference from the configuration in FIG. 7 is that the terminal device (A) 10 has an encoding control unit.
41, a decoding control unit 43, a terminal device (B) 20, a terminal device (C) 30, and a terminal device (D) 40 in which an encoding control unit 44 and a decoding control unit 46 are provided.

In FIG. 11, a start message (aa)
Is a control code 150, a terminal identifier 151, a start identifier 15
This configuration is similar to the configuration of FIG. The difference from the configuration of FIG. 9 is that a necessary band 153 is provided in the start message. Change message (ab)
Is a control code 155 indicating a change message.
, A terminal identifier 156 for identifying a terminal transmitting the multimedia information, a change identifier 157 indicating a change message, and a required band 158 indicating a required band. The arbiter arbitration message (c) includes a control code 181 indicating an arbiter arbitration message,
It is composed of a terminal identifier 182 indicating an arbiter. The end message (c) includes the control code 160 and the terminal identifier 161.
And an end identifier 162. The above configuration is similar to the configuration of FIG. Trigger information message (d)
Is composed of a control code 170, terminal identifiers 171, 173, and 175, trigger counts 191, 192, and 193, and transmission times 185, 186, and 187.

The operation of the multimedia information transmitting / receiving system of the fourth embodiment configured as described above will be described below. The difference from the multimedia information transmitting / receiving system of the third embodiment is that the bandwidth required by each terminal device can be declared. When each terminal device transmits a start message, a bandwidth required by each terminal device is specified. The arbiter creates a trigger information message based on the message and transmits it to each terminal device.

According to the second and fourth embodiments, the band used is changed according to the multimedia information transmitted by the terminal device, and is notified to the arbiter, so that the timing information corresponding to the change is obtained. , Communication can be effectively used on the band on the transmission path.
Such a change of the band may be set by the arbiter itself and notified to the terminal device, or may be configured so that only one of the terminal device and the arbiter can make the change.

Further, the timing at which each terminal device transmits an end message or a change message to the arbiter 10 can be transmitted at a timing assigned to each terminal device.

Further, in the first and second embodiments, a plurality of arbiters can determine timing information while cooperating. Further, in the third and fourth embodiments, a plurality of arbiters can determine trigger information while cooperating.

[0087]

As described above, according to the present invention, when information having a time attribute is transmitted and received between terminal devices, the arbiter dynamically allocates a transmission band to each terminal device, and transmits information from the arbiter. , The transmission timing of each terminal device is secured by itself, so that each terminal device can transmit and receive information having a time attribute without causing a collision. Further, by providing the terminal device with a mechanism for notifying the necessary band of the transmission data in advance, the arbiter can allocate a necessary and sufficient band, and it is possible to provide a system capable of operating resources without waste.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a multimedia information transmitting / receiving system according to a first embodiment of the present invention;

FIG. 2 is a timing chart of data transmission from each terminal to a transmission path according to the first embodiment of the present invention;

3A is a format diagram showing a data structure of a start message in the first embodiment, FIG. 3B is a format diagram showing a data structure of an arbiter arbitration message in the first embodiment, and FIG. FIG. 9D is a format diagram showing a data structure of an end message according to the embodiment; FIG. 9D is a format diagram showing a data structure of timing information according to the first embodiment;

FIG. 4 is a block diagram showing a configuration of a multimedia information transmitting / receiving system according to a second embodiment of the present invention;

FIG. 5 is a timing chart of data transmission from each terminal to a transmission path according to the second embodiment of the present invention;

FIG. 6A is a format diagram showing a data structure of a start message according to the second embodiment;
Format diagram showing the data structure of the change message in the second embodiment, (b) format diagram showing the data structure of the arbiter arbitration message in the second embodiment, and (c) data of the end message in the second embodiment A format diagram showing a configuration, (d) a format diagram showing a data configuration of timing information in the second embodiment,

FIG. 7 is a block diagram showing a configuration of a multimedia information transmitting / receiving system according to a third embodiment of the present invention;

FIG. 8 is a timing chart of data transmission from each terminal to a transmission path according to the third embodiment of the present invention;

9A is a format diagram illustrating a data structure of a start message according to the third embodiment, FIG. 9B is a format diagram illustrating a data structure of an arbiter arbitration message according to the third embodiment, and FIG. FIG. 14D is a format diagram illustrating a data structure of an end message according to the third embodiment; (d) a format diagram illustrating a data structure of timing information according to the third embodiment;

FIG. 10 is a block diagram showing a configuration of a multimedia information transmitting / receiving system according to a fourth embodiment of the present invention;

11A is a format diagram illustrating a data structure of a start message according to the fourth embodiment, FIG. 11A is a format diagram illustrating a data structure of a change message according to the fourth embodiment, and FIG. A format diagram showing a data configuration of an arbiter arbitration message in the embodiment, (c) a format diagram showing a data configuration of an end message in the fourth embodiment, and (d) a data configuration of timing information in the fourth embodiment. Format diagram,

FIG. 12 is a block diagram showing a configuration of a conventional information transmitting / receiving system;

FIG. 13 is a timing chart of data transmission from each terminal to a transmission line in a conventional information transmission / reception system.

[Explanation of symbols]

 10 Terminal device (A), arbiter 11, 31, 71 Transmitting unit 12, 32, 72 Receiving unit 13, 33, 73 Transmitting data storage unit 14, 34, 74 Receiving data storage unit 15, 35 Decoder unit 16, 36, 76 Output unit 17, 37 Encoder unit 18, 38 Timing arbitration unit 19 Arbitrate unit 20 Terminal device (B) 25 Camera (B) 30 Terminal device (C) 40 Terminal device (D) 41, 44 Coding control unit 45 Camera (D ) 42, 48, 75 Channel state detector 43, 46 Decoding controller 51, 56 Trigger generator 50 Transmission line 60 Camera (A) 70 Terminal (E) 77 Input 80 Camera (C) 90 Terminal (F )

Claims (4)

[Claims] In a multimedia information transmitting / receiving system for connecting a plurality of terminal devices via a transmission path and realizing mutual communication between the terminal devices, a representative right is dynamically given to a terminal device by arbitration between the respective terminal devices. Means for giving, arbiter which is a terminal device having a representative right, means for calculating timing information for arbitrating the timing of transmitting multimedia information, means for notifying the timing information to the terminal device, Means for transmitting to the transmission path based on the timing information when the terminal device sends out the multimedia information. A transmission access control method for the multimedia information. Means for notifying the arbiter of a band required for the terminal device to transmit multimedia information in advance, wherein the arbiter secures a necessary band by notifying a band of the timing information. 2. The transmission access control method for multimedia information according to claim 1, wherein 3. A multimedia information transmitting / receiving system that connects a plurality of terminal devices via a transmission path and realizes mutual communication between the terminal devices. Means for providing, arbiter which is a terminal device having a representation right, means for calculating trigger information for arbitrating timing for transmitting multimedia information, and trigger for transmitting the multimedia information by the arbiter to the terminal device. Means for notifying the transmission of multimedia information. 4. The system according to claim 1, further comprising: a means for notifying the arbiter of a band required for the terminal device to transmit multimedia information in advance, and transmitting the trigger information so that the arbiter secures a necessary band by notifying the band. 4. The transmission access control method for multimedia information according to claim 3, wherein the calculation is performed.