WO2002056555A1 - Multipoint communication service unit - Google Patents

Abstract

Circuit processing units (2a to 2n) of a multipoint communication service unit (1) have therein respective transmission buffers (21a to 21n) where data to be outputted to terminals (8a to 8n) is temporarily stored. The remaining amount of data in the transmission buffers (21a to 21n) is measured and transmitted to a device control unit (7). If the device control unit (7) judges from the transmitted remaining amount that the transmission buffers (21a to 21n) come almost to an overflow state or become an overflow state, the device control unit (7) notifies reception buffers, not shown, of the circuit processing units (2a to 2n) and discards the data sent from terminals.

Description

 Description Multipoint communication service unit Technical field

 The present invention relates to a multipoint communication service unit connected to a plurality of terminals and providing a multipoint communication service to the plurality of terminals.

Background art

 FIG. 1 is a configuration diagram showing a conventional multipoint communication service unit. In the figure, 1 is a multipoint communication service unit, 8a to 8f are terminals, and 9 is a line.

 When performing multipoint communication using the multipoint communication service unit 1, the multipoint communication service unit 1 and each of the terminals 8a to 8f exchange the mutually transmittable processing capacity. Communication is performed at the same communication speed including the rate of each media information.

 At this time, the multipoint communication service unit 1 and each of the terminals 8a to 8d are connected via the line 9, and after starting communication, the data from one selected terminal is copied. Sent to other terminals. As a method of selecting a terminal to copy the data, there is a method of detecting a speaker and transmitting the data from the speaker's terminal to another terminal.

Since the conventional multipoint communication service unit was configured as described above, it was assumed that transmission was performed at the same communication speed including the communication rate of each piece of media information between terminals 8a to 8n. If the communication conditions such as the communication speed and communication volume of each terminal are different, the multipoint communication service There was a problem that buffer overflow occurred in the unit and each terminal, and multipoint communication service could not be provided normally.

 The present invention has been made in order to solve the above-described problems. Even in a case where multipoint communication is performed between terminals having different communication conditions such as communication speed and communication data amount, the service unit 1 can be used. The purpose of the present invention is to obtain a multipoint communication service unit that can normally realize multipoint communication without causing a buffer overflow in each terminal. Disclosure of the invention

 The multipoint communication service unit according to the present invention detects whether or not the buffer for temporarily storing various media information of the multipoint communication service is in the state of overflow or overflow, and When the near-barf opening or the overflow state is detected, the amount of media information in the buffer is controlled so as to eliminate the near-overflow or overflow state. '

 This has the effect that multipoint communication can be executed normally. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a configuration diagram showing a conventional multipoint communication service unit. FIG. 2 is a configuration diagram showing a connection between the multipoint communication service unit and each terminal according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an example of a multiplex configuration unit of media information according to Embodiment 5 of the present invention. · FIG. 4 is an explanatory diagram showing an example of setting priorities for video data according to Embodiment 5 of the present invention. FIG. 5 is an explanatory diagram showing an example of a method of setting priorities in a video image according to Embodiment 7 of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, in order to explain this invention in greater detail, the preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Embodiment 1.

 FIG. 2 is a configuration diagram showing a connection between the multipoint communication service unit and each terminal according to the first embodiment of the present invention. In the figure, 1 is a multipoint communication service unit, 2a to 2n are line processing units, 21a to 21n are transmission buffers, 3a to 3n are media demultiplexing units, and 4 is a video processing unit. Reference numeral 5 is a voice processing unit, 6 is a data processing unit, 7 is a device control unit, 8a to 8n are terminals, 81a to 81n are reception buffers, and 9 is a line. Although not shown in FIG. 2, the device control unit 7 includes a line processing unit 2a to 2n, a media demultiplexing unit 3a to 3n, a video processing unit 4, an audio processing unit 5, and a data processing unit. It is assumed that these units are connected by signal lines (not shown) so that various instructions can be issued to each processing unit in the multipoint communication service unit 1 such as the processing unit 6. Although not shown in FIG. 2, the line processing units 2a to 2n are provided with reception buffers for receiving data transmitted from the corresponding terminals 8a to 8n. Each of the terminals 8a to 8n is provided with a transmission buffer for temporarily storing data to be transmitted to the multipoint communication service unit 1.

Here, the line 9 shown in FIG. 2 may be a circuit-switched network or a packet-switched network. In the case of a circuit-switched network, the communication speed may be different for each line or may be the same but may be multiplexed. Communication is possible even if the speed of the media information differs. In other words, the connected communication network is a circuit-switched network. The transmission rate of the communication path used by each terminal may be different from each other, and the transmission rate of the communication path used by each terminal may be the same, but the information rate of each piece of media information may be different. A plurality of different types may be used. Further, the communication network to be connected may be a packet switching network, and a plurality of types of media information having different information rates may be used. The same applies to other embodiments 2 to 10 described below.

 A plurality of line processing units 2a to 2n and a plurality of media demultiplexing units 3a to 3n are provided so that the terminals 8a to 8n can simultaneously enjoy the multipoint communication service. The number of units that can simultaneously enjoy the multipoint communication service is determined.However, as shown in Fig. 2, the number of line processing units 2a to 2n and Need not be the same.

 Next, the operation will be described.

 First, when an arbitrary terminal initiates a call and sends media information including voice, video, data, etc. using the multipoint communication service to the multipoint communication service unit 1, the multipoint communication service unit 1 The multipoint communication service is started, a communication channel is formed via the line 9 under the control of the device control unit 7, and a group that provides the multipoint communication service using the line processing units 2a to 2n is formed. The terminals 8a to 8n to be configured are connected to each other in each multipoint communication service group. In the following description, for convenience, the terminals 8a to 8n will be described as constituting the same group in which the same multipoint communication service is provided.

Then, in the multipoint communication service unit 1, the reception buffers (not shown) of the line processing units 2a to 2n corresponding to the arbitrary terminals 8a to 8n that made the call store the media information from the calling terminal. Under the control of the device control unit 7, and converts the media information into the corresponding media demultiplexing units 3a to 3a. n, and performs predetermined processing in the video processing unit 4, audio processing unit 5, data processing unit 6, etc., and sends them to the media demultiplexing units 3a to 3n in a predetermined group that provides the multipoint communication service. Multiplexed and sent to the corresponding line processing units 2a to 2II.

 Then, each of the line processing units 2 a to 2 n temporarily holds the media information to be transmitted to each of the terminals 8 a to 8 n by the built-in transmission buffer 21 a to 21 n, It transmits to each of the terminals 8a to 8n, measures the remaining amount of the transmission buffers 21a to 21n, and notifies the device control unit of the measured remaining amount.

 The device control unit 7 transmits the transmission buffers of the line processing units 2a to 2n based on the status of the transmission buffers 21a to 21n notified from the line processing units 2a to 2n. It is determined whether or not 21a to 21n are in the vicinity of the overflow mouth or in the overflow state.

 Then, when it is determined that the transmission buffer of a certain line processing unit is in the near-overflow state or in the overflow state, the device control unit 7 determines the line corresponding to the terminal that has transmitted the media information. A command is issued to the processing unit, and the receiving media information from the terminal input to the receiving buffer (not shown) is discarded so as to avoid the overflow or the overflow state.

 As described above, according to the first embodiment, when the transmission buffers 21a to 21n of the line processing units 2a to 2n become close to overflow or overflow, the overbuffers are immediately transmitted. By avoiding the near-row or overflow state, multipoint communication can be executed normally.

Also, media information is discarded in the reception buffer of the line processing unit corresponding to the terminal that sent the media information. The reception buffer capacity of 2a to 2n is the same, and the amount of media information transmitted to each terminal 8a to 8n is the same, and each line processing unit 2a to 2n is similarly When the overflow is about to occur or an overflow occurs, the media information is discarded only by the reception buffer of the line processing unit corresponding to the terminal that transmitted the media information, and all the line processing units 2a to 2n are efficiently processed. It is possible to avoid an overflow or near-overflow state in the transmission buffers 2 la to 2 In and the reception buffers 8 la to 8 In of the terminals 8 a to 8 n. Embodiment 2.

 Next, a second embodiment will be described. The configuration of the second embodiment is the same as that of the first embodiment and the like shown in FIG. 2, and only the operation will be described with reference to FIG.

 In the case of the second embodiment, as shown in FIG. 2, the terminals 8a to 8n each receive and temporarily store data transmitted by the multipoint communication service unit 1 in each of the terminals 8a to 8n. Each of the terminals 8a to 8n itself measures the remaining storage capacity of the reception buffer 81a to 81n.

 Then, each of the terminals 8a to 8n detects whether or not the built-in receiving buffers 8la to 81n are near the overflow port or in the overflow state. When the flow state is detected, each of the terminals 8 a to 8 n notifies the device control unit 7 of the communication control unit 1.

Then, the device control unit 7 responds to the notification from the terminal that has just entered the overflow state or the terminal that has entered the overflow-one state, so that one of the reception buffers 8 la to 8 In in each of the terminals 8 a to 8 n overflows. Upcoming or over If it is determined that the media is in the flow state, it issues a command to the line processing unit corresponding to the terminal that transmitted the media information, and inputs the received media from the terminal to the reception buffer (not shown) of the line processing unit. The information is discarded so that the overflow or the overflow state can be avoided. In the second embodiment, each of the terminals 8a to 8n has its own reception buffer 81a to 8In. Although it has been described that whether or not an overflow is about to occur or an overflow state is detected and the device control unit 7 of the communication control unit 1 is notified, the present invention is not limited to this. The terminals 8a to 8n only measure the remaining storage capacity of the reception buffers 81a to 81n and notify the multipoint communication service unit 1, and the reception buffers 8la to 81n Over the mouth Rui is in overflow opening one-state. Determines whether, of course may be performed by a multipoint communication service Interview device controller 7 of Knitting sheet 1 and the like.

 As described above, according to the second embodiment, any one of the reception buffers 81 a to 81 η of the terminals 8 a to 8 n that enjoy the multipoint communication service is assigned Even in the case of an upcoming or overflow state, the media information is discarded in the reception buffer or the transmission buffer of the line processing unit as in the case of Embodiment 1, so that the overflow immediately occurs. There is an effect that multipoint communication can be executed normally by avoiding the state of being close to one flow or an overflow state. Embodiment 3.

Next, a third embodiment will be described. Since the configuration of the third embodiment is the same as the configuration of the first embodiment shown in FIG. 2, only the operation will be described with reference to FIG. In the case of the third embodiment, the device control unit 7 of the multipoint communication service unit 1 communicates with the terminals 8 a to 8 via the media demultiplexing units 3 a to 3 n and the line processing units 2 a to 2 n at the start of communication. Communication and exchange of various communication parameters with n, grasping each other's processing capacity such as buffer capacity, and transmitting buffer in multipoint communication service unit 1 before starting multipoint communication service The reception buffers 8 la to 8 In in the terminals 21 a to 21 n or the terminals 8 a to 8 n store the amount of data to be transmitted, and when the overflow is near or over. It is determined whether or not an overflow condition exists.

 Then, when a reception buffer (not shown) of a certain line processing unit receives media information using a multipoint service, the device control unit 7 measures the amount of information and grasps the measured value and the communication value at the start of communication. Based on the processing capacity, the transmission buffers 21 a to 21 n of the multipoint communication service unit 1 or the reception buffers 81 a to 81 n of the terminals 8 a to 8 n are overflowed. If it is determined that the mouth is approaching or overflow, control is performed to discard the data from the corresponding terminal that is input to the reception buffer of the line processing unit that has received the media information.

 As described above, according to the third embodiment, at the start of communication or before the start of communication, etc., the mutual processing capabilities grasped by the capability exchange of communication control parameters between terminals 8a to 8n. The transmission buffers 21 a to 21 η of the line processing units 2 a to 2 n or the reception buffers 81 a to 8 In in the terminals 8 a to 8 n overflow based on Since it is avoided that the state is close or overflow, the multipoint communication can be executed normally. Embodiment 4.

Next, a fourth embodiment will be described. The configuration of Embodiment 4 is as follows. Since the configuration is the same as that of the first embodiment shown in FIG. 2, only the operation will be described with reference to FIG. The operations of the parts not described are the same as those of the first to third embodiments.

 In the case of Embodiment 4, the device control unit 部 of the multipoint communication service unit 1 includes the transmission buffers 21 a to 2 In of the line processing units 2 a to 2 n or the terminals 8 a to 8 n. If any one of the receiving buffers 81a to 81n, for example, the line processing unit 2b determines that the overflow is about to occur or is in the overflow state, the overflow buffer is near or overflows. The transmission buffer 21b of the line processing unit 2b in the state is notified and the transmission buffer 21b is stored when the transmission buffer 21b is input or the transmission buffer 21b is input. The transmission buffer 21b is discarded so that the transmission buffer 21b is close to the overflow or the overflow state can be avoided.

 As described above, according to the fourth embodiment, even if the transmission buffers 21a to 2In of the line processing units 2a to 2n are close to overflow or in the overflow state, Since the overflow or near-overflow state is avoided immediately, there is an effect that multipoint communication can be executed normally.

Also, instead of discarding the media information in the reception buffer of the line processing unit corresponding to the terminal that transmitted the media information, the transmission media information should be discarded in the transmission buffer of the line processing unit near or overflowing the overflow. Therefore, if the transmission buffer capacity of each line processing unit 2a to 2n is different, or if the maximum data amount or media type of the media information received by each terminal is different, for example, video and audio and data A terminal that receives the same multipoint communication service for various types of media information, such as a terminal that receives all media information, a terminal that receives only audio, and a terminal that receives only data overnight, , Maximum data reception Even if the volume / media type is different, the transmission buffer of each line processing unit 2a to 2n or the maximum data volume of media information received by each terminal / data can be discarded according to the media type This has the effect. Embodiment 5

 Next, a fifth embodiment will be described. Note that the configuration of the fifth embodiment is the same as the configuration of the first embodiment shown in FIG. 2, etc., and therefore only the operation will be described with reference to FIG. The operations of the parts not described are the same as those of the first to fourth embodiments.

 In the case of the fifth embodiment, the device control unit の of the multipoint communication service unit 1 transmits the transmission buffers 21 a to 21 n of the line processing units 2 a to 2 n, or the transmission buffers 21 a to 21 n of the terminals 8 a to 8 n. When it is determined that any of the reception buffer 8 1 a 8 1 n has entered the near-overflow or overflow state, it notifies the media demultiplexing sections 3 a to 3 n, In accordance with the state of the communication channel for each communication channel, for example, as shown in FIG. 3 to be described later, the data 'video' and audio are discarded from each media processing unit for each multiplexing configuration unit, or As shown in Fig. 4, one or more of the video processing unit 4, the audio processing unit 5, and the data processing unit 6 are notified and the media processing is performed for each meaningful unit of each media information. Discard data, video and audio from the department. ·

 As a result, the transmission buffers 2 la to 2 In of the line processing units 2 a to 2 n or the reception buffers 81 a to 8 In in the terminals 8 a to 8 n overflow. It can be avoided, and stable multipoint communication becomes possible. FIG. 3 is an explanatory diagram showing an example of a multiplex configuration unit of media information according to Embodiment 5 of the present invention.

As shown in FIG. 3, the media demultiplexers 3 a to 3 n Each piece of media information, such as data and data, is packetized and transmitted as a unit of multiplexing. For this reason, the media multiplexing / demultiplexing units 3 a to 3 n of the fifth embodiment are configured to transmit the transmission buffers 21 a to 21 n of the line processing units 2 a to 2 n in accordance with an instruction from the device control unit 7. Alternatively, to prevent the receiving buffers 81a to 81n in the terminals 8a to 8n from approaching the overflow or being in a state of overflow, the audio 1, video 1, video 2, For example, a plurality of frame units, a plurality of slice units, a plurality of macro block units, etc. shown in FIG. Perform disposal. In this way, the impact of discarding data can be reduced.

 FIG. 4 is an explanatory diagram showing an example of a method for setting a priority for video data according to the fifth embodiment. Taking the video data shown in Fig. 4 as an example, meaningful units of media information will be described.

 A video image is composed of a plurality of continuous frames, a frame is composed of a plurality of slices, and a slice is composed of a plurality of macro programs. It is configured. Therefore, according to the fifth embodiment, the video processing unit 4 transmits the transmission buffers 21 a to 21 η of the line processing units 2 a to 2 n or the terminal according to an instruction of the device control unit 7. When the receiving buffer 81a to 81n in 8a to 8n discards the video data so as to avoid the overflow or the overflow state, these units, That is, discarding is performed for each frame unit, for each slice unit, or for each Mac mouth block unit.

As described above, according to Embodiment 5, the transmission buffers 21 a to 21 n of the line processing units 2 a to 2 n or the reception buffers 81 a of the terminals 8 a to 8 n ~ 8 1n is in the state of overflow or overflow, and each media information is discarded for each meaningful unit of media information. Since the data is discarded, it is possible to effectively execute the multipoint communication by effectively avoiding the buffer overflow or the overflow state by means of a meaningful unit of the media information. There is. Embodiment 6

 Next, a sixth embodiment will be described. Since the configuration of the sixth embodiment is the same as the configuration of the first embodiment shown in FIG. 2, etc., only the operation will be described with reference to FIG. The operations of the parts not described are the same as those of the first to fourth embodiments.

 In the case of Embodiment 6, the device control unit 部 of the multipoint communication service unit 1 includes the transmission buffers 21 a to 21 η of the line processing units 2 a to 2 n or the terminals 8 a to 8 n. When it is determined that any of the receiving buffers 81a to 81n is in the vicinity of overflow or overflow, the media demultiplexing sections 3a to 3n give priority to each piece of media information. , Or based on the priority order set in the media information in advance, so that media with lower priority order are discarded.

 For example, if the priority is assigned in ascending order of data amount such as data> audio> video, discard the images in descending order of priority and in descending order of data amount. Of course, on the contrary, it is of course possible to assign a higher priority to the data with the larger data amount and to discard the media information with the smaller data amount in order.

As described above, according to the sixth embodiment, media information is discarded in order based on the priority order of each piece of media information, and communication processing is performed preferentially, for example, from important media information having a higher priority order. The transmission buffer 21a to 21n of the line processing units 2a to 2n or the reception buffer 8.1a to 81n in the terminal 8a to 8n overflows. I tried to avoid it, Multipoint communication can be executed normally by avoiding the buffer overflow or the overflow state more effectively. Implementation φ form 7.

 Next, a seventh embodiment will be described. Note that the configuration of the seventh embodiment is the same as the configuration of the first embodiment shown in FIG. 2, and therefore, only the operation will be described with reference to FIG. The operations of the parts not described are the same as the operations of the first to fourth embodiments.

 In the case of the seventh embodiment, the device control unit の of the multipoint communication service unit 1 transmits the transmission buffers 21 a to 21 η of the line processing units 2 a to 2 n or the reception within the terminals 8 a to 8 n. When it is determined that any one of the buffers 8 la to 8 In is near overflow or overflow, the video processing unit 4, the audio processing unit 5, and the data processing unit 6 are notified. Then, in each of the video processing unit 4, the audio processing unit 5, and the data processing unit 6, for each media information, each transmission from each of the terminals 8a to 8n within the same media information, and for the same transmission Even the same media information is to be discarded from low priority data according to the priority set for the constituent unit.

 FIG. 5 is an explanatory diagram showing an example of a priority setting method using video data as an example according to Embodiment 7 of the present invention.

 Video data encoded by MPEG is frequency-converted in units specified by the MPEG standard, and is converted from low-frequency components to high-frequency components. Therefore, for example, a higher priority is set to the transform coefficients of the low-frequency components with a predetermined threshold as a boundary.

Thus, in Embodiment 7, the multipoint communication service unit 1 When the transmission buffers 21a to 21n of the line processing units 2a to 2n or the reception buffers 81a to 8In in the terminals 8a to 8n are in the overflow state, the video data is discarded. In this case, it is possible to discard the high-frequency components with low importance based on the priority order and transmit the conversion coefficients of the low-frequency components with high importance.

 In the seventh embodiment, in each of the video processing unit 4, the audio processing unit 5, and the data processing unit 6, in each of the media information, each transmission from each of the terminals 8a to 8n in the media information is performed. Also, in the same transmission, it has been described that the low priority data is discarded in accordance with the priority set for the information unit. However, the present invention is not limited to this. A priority order is assigned in the audio processing unit 5 and the data processing unit 6. For example, in the video processing unit 4 having a low priority order, video information having a lower priority order is discarded. If the transmission buffer 21a to 21n of 2a to 2n or the reception buffer 81a to 81n in the terminal 8a to 8n cannot cancel the overbuff state, the following The audio processing unit 5 in the priority order discards the audio information based on the priority order. Well, also, the video processing unit 4, voice processing unit 5, may be put on the priority mechanism to all of Meda information irrespective of the data processing unit 6.

As described above, according to the seventh embodiment, each transmission from each of the terminals 8a to 8n within the same media information, or even the same media information of the same transmission, according to the priority set in the configuration unit, The transmission buffers 21a to 2In of the line processing units 2a to 2n or the reception buffers 8la to 8In in the terminals 8a to 8n are made to discard low-priority data. Since overflow is avoided, even if the transmission buffers 21a to 21 of the line processing units 2a to 2n are close to overflow or are in an overflow state, they are immediately and Avoid multi-point communication more effectively There is an effect that can be performed.

Embodiment 8

 Next, an eighth embodiment will be described. The configuration of the eighth embodiment is the same as the configuration of the first embodiment or the like shown in FIG. 2, and therefore, only the operation will be described with reference to FIG. The operations of the parts not described are the same as those of the first to fourth embodiments.

 In the case of the eighth embodiment, the device control unit 7 of the multipoint communication service unit 1 includes the transmission buffers 21 a to 21 η of the line processing units 2 a to 2 η or the terminals 8 a to 8 η. If it is determined that one of the receiving sofas 8 1 a to 8 In has entered the over-flow or near-over state, the media demultiplexing sections 3 a to 3 n and the line Through the processing units 2a to 2n, etc., an instruction is issued to request the terminal that is the source of the media information that is near the overflow or the overflow state to request a decrease in the transmission rate. .

 Then, the terminal requested to decrease the transmission rate reduces the transmission rate based on the request and decreases the transmission data.

 In the eighth embodiment, it has been described that the terminal that is the source of the media information that has reached the state of overflow or overflow has been requested to reduce the transmission rate. The present invention is not limited to this, and it is a matter of course that an instruction to reduce the transmission rate may be given to all terminals 8a to 8n that receive the multipoint communication service.

As described above, according to Embodiment 8, the transmission rate at the terminal that is the source of the media information is reduced, and transmission buffers 2 la to 2 In of line processing units 2 a to 2 n are overloaded. By avoiding near-flow or overflow condition, it is possible to avoid over-close-close or over-close condition immediately and more effectively. However, there is an effect that multipoint communication can be executed normally. Embodiment 9

 Next, a ninth embodiment will be described. Note that the configuration of the ninth embodiment is the same as the configuration of the first embodiment shown in FIG. 2, and therefore, only the operation will be described with reference to FIG. The operations of the parts not described are the same as those of the first to fourth embodiments.

 In the case of the ninth embodiment, as in the case of the third embodiment and the like, the device control unit of the multipoint communication service unit 1 sets the media demultiplexing units 3 a to 3 n and the line processing unit at the start of communication. Using 2a to 2n, control to communicate various communication parameters with the terminals 8a to 8n, grasp the processing capacity such as the buffer capacity of each other, and before starting multipoint communication, How much data is left in the transmission buffer 21 a to 21 η in the multipoint communication service unit 1 or the reception buffer 81 a to 81 n in the terminal 8 a to 8 η Determining whether or not the flow is about to be reached when the flow is about to occur. Then, similarly to the third embodiment, the transmission buffers 2 la to 2 In of the multipoint communication service unit 1 or the reception buffers 81 a to 8 n of the terminals 8 a to 8 n. If it is determined that any one of 1 n is about to overflow or has entered an overflow state, the overflow is performed via the media demultiplexing units 3 a to 3 n and the line processing units 2 a to 2 n. It instructs the terminal that is the source of the media information that has just come in or has overflowed to request a decrease in the transmission rate.

Then, the terminal requested to decrease the transmission rate reduces the transmission rate based on the request and decreases the transmission data. 'In Embodiment 9, the terminal that is the source of the media information that is about to overflow or has overflowed is notified of the transmission rate. Although it has been described that the reduction is requested, the present invention is not limited to this, and an instruction to reduce the transmission rate may be given to all terminals 8a to 8n that receive the multipoint communication service. Of course it is good.

 As described above, according to the ninth embodiment, similarly to the eighth embodiment, the transmission rate of the terminal that is the source of the media information is reduced, and the transmission buffer of the line processing units 2a to 2n is reduced. In this way, it is possible to avoid the over-flow state or the overflow state of the over-flow state or the over-flow state immediately or more effectively. There is an effect that multipoint communication can be executed normally while avoiding an overflow situation. Embodiment 10

 Next, a tenth embodiment will be described. The configuration of the tenth embodiment is the same as the configuration of the first embodiment shown in FIG. 2, and therefore, only the operation will be described with reference to FIG. The operation of the parts not described is the same as in the first to third embodiments.

In the case of the tenth embodiment, the device control unit 7 of the multipoint communication service unit 1 includes all buffers for temporarily storing media information provided by the same multipoint communication service, that is, the line processing unit shown in FIG. Any of the transmission buffers 21 to 211 of 2a to 2n or the reception buffers 8la to 8In in the terminals 8a to 8n is near or overflowing. If it is determined that the terminal has entered the state, based on the communication control parameters used during the communication, the terminal having the lowest capability determines the transmission rate at which transmission and reception can be performed, and the media demultiplexing unit 3a To 3n and all terminals 8a to 8n that receive the provision of the multipoint communication service via the line processing units 2a to 2n, or all terminals that can be media information transmission sources. Instruct the terminal which has the lowest capability to reduce the transmission rate to a transmission rate at which transmission and reception can be performed.

 Then, the terminal requested to decrease the transmission rate reduces the transmission rate based on the request and decreases the transmission data.

 As described above, according to Embodiment 10, the transmission rate at which the terminal having the lowest capability can transmit and receive is determined based on the communication control parameters used during communication, and the same multipoint communication is performed. All terminals that receive the service 8a

Since the transmission rate is reduced to the transmission rate for 88 n, etc., the transmission buffers 21 a 2 21 n of the line processing units 2 a 2 2 n are used for the transmission near the overflow. Alternatively, even if an overflow occurs, it is possible to avoid the problem more quickly and effectively, and the multipoint communication can be executed normally. Industrial applicability

 As described above, the multipoint communication service unit according to the present invention is suitable for avoiding the overflow of transmission and reception and preventing multipoint communication, and performing multipoint communication normally.

Claims

Scope of Claim 1. A multipoint communication service unit connected to a plurality of terminals and providing various media information to the plurality of terminals by a multipoint communication service.  It detects whether the buffer for temporarily storing various media information of the multipoint communication service is near overflow or overflow status, and if it detects the above overflow or overflow status, A multipoint communication service unit, wherein the amount of media information in the buffer is controlled so as to eliminate the near-overflow or near-overflow state. 2. The multi-point communication service unit described in claim 1 is a transmission buffer provided in the unit and temporarily storing data to be transmitted to each terminal. G. 3. The multipoint communication service unit according to claim 1, wherein the buffer is a reception buffer provided in each terminal and temporarily storing data received by each terminal. 4. The multipoint communication service unit according to claim 1, wherein near-overflow or overflow status is detected based on communication control parameters transmitted / received to / from a terminal at the start of communication. 5. By discarding the media information for each communication channel according to the state of each communication channel, the near-overflow or overflow can be achieved. 2. The multipoint communication service unit according to claim 1, wherein the amount of media information in the buffer is controlled so as to eliminate the state. 6. The amount of media information in the buffer so that the overflow or near-overflow condition is eliminated by discarding the media information for each multiplexing system unit according to the state of each communication channel for each communication channel. 6. The multipoint communication service unit according to claim 5, wherein the multipoint communication service unit controls the communication. 7. In accordance with the state of each communication channel for each communication channel, the media information is discarded at meaningful delimiters for decoding each piece of media information, so that the near-overflow state or the overflow state can be resolved. 6. The multipoint communication service unit according to claim 5, wherein the amount of media information in the buffer is controlled. 8. Prioritize each media information and discard the media information with the lowest priority in order to eliminate the media information in the buffer so as to eliminate the overflow or overflow status. 2. The multipoint communication service unit according to claim 1, wherein an amount of the multipoint communication service is controlled. 9. By assigning priorities to different types of coded information in the same media information and discarding the coded information with the lowest priority in order, it is possible to overwrite or overwrite 2. The multipoint communication service unit according to claim 1, wherein the amount of media information in the buffer is controlled so as to eliminate the state. 10. Control the amount of media information in the buffer so that the overflow or near-overflow condition is eliminated by instructing the terminal that is the source of the media information to reduce the amount of transmitted media information. The multipoint communication service unit according to claim 1, wherein: 1 1. Determine the transmission rate at which media information provided by the same multipoint communication service can be temporarily transmitted and received while avoiding or nearing the overflow of all buffers that temporarily store media information provided by the same multipoint communication service. 10. The multipoint communication service unit according to claim 10, wherein all terminals participating in the communication service are instructed to suppress the subsequent transmission rate and the transmission rate to the above determined transmission rate. . 12. The multipoint communication service unit according to claim 1, wherein a communication network to be connected is a circuit switching network, and a plurality of types of communication paths used by each terminal have different transmission rates. . 1 3. The communication network to be connected is a circuit-switched network, and the transmission rate of the communication path used by each terminal is the same, but the information rate of each piece of media information is different from each other. A multi-point communication service kit according to item 1.  14. The multipoint communication service unit according to claim 1, wherein the communication network to be connected is a packet switching network, and a plurality of types of media information have different information rates.