JPH0799526A - Communication control system - Google Patents

Abstract

PURPOSE:To allow the system to cope with a setting request of a new communication connection with flexibility by reducing bands of existing communication connection so as to supplement deficiency of idle bands. CONSTITUTION:Communication connection information representing a margin band being an idle communication band of a line is stored and managed in a communication connection management section 23 of a memory 13 in a terminal equipment. When a new communication connection setup request comes from a communication program in its own terminal equipment memory 13 or other terminal equipment, a management section 23 calculates a communication band required for the requested connection and when the communication band cannot be confirmed as a margin band, the band of the set communication connection is revised partly to a degree not lower than the lower limit and the band is allocated to a new communication connection. Simultaneously communication band information data of a management table 24 are updated. Thus, even when no margin is in existence in the communication band, a required band is secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control system, and more particularly to a communication control system suitable for application to a multimedia terminal which establishes a plurality of connections within a predetermined communication band and communicates between programs.

[0002]

2. Description of the Related Art In a terminal device connected to a switching network such as ISDN, when a connection setting request for communicating with another terminal device is received from a program running on the terminal device, or when the above ISDN is used. When a request for setting a communication connection with the own terminal is received from another connected terminal device, the communication control unit sets a new communication connection having a communication band according to the request.

Conventionally, in such inter-terminal communication, the band allocated to the communication connection remains unchanged until the communication connection is released, and the band is not changed during the communication. Also, the size of the communication band that can be used for terminal-to-terminal communication is predetermined for each terminal, and the unused band at the time of setting a new communication connection is insufficient, and the communication band requested by the program If it could not be secured, the setting of a new communication connection was rejected.

In terminal devices using a communication network, service functions such as remote login, file transfer, moving image communication, etc. are diversified, and recently, for example, conference systems and consultation systems are connected to each other via a network. A system has been put into practical use in which a plurality of windows are formed on a terminal screen, a connection is set for each window, and a plurality of types of communication services are simultaneously executed between terminals.

[0005]

As described above, when a plurality of communication services are used at the same time by the same terminal device, the conventional connection setting method described above requires a new communication if there is no margin in the communication band allowed to the terminal. There was a problem that the communication service could not be executed with various communication connections.

An object of the present invention is to provide a communication control system which has flexibility in band allocation of communication connections and is capable of executing a service by setting a new communication connection within the restriction of an allowable communication band. .

[0007]

In order to achieve the above object, according to the present invention, a plurality of communication connections are set on a line having a predetermined communication band, and a plurality of programs are exchanged with another terminal device. In a communication control method for a communication system that performs communication, an unused communication band in the line is stored, and when there is a request for setting a new communication connection, the unused communication band is set in the new communication connection. When the required communication band is insufficient, the communication band of any existing communication connection is reduced to compensate for the insufficient communication band, and then the new communication connection is set. To do.

In order to determine the room for band reduction in an existing communication connection, when requesting a new communication connection setting, for example, the upper limit value and the lower limit value of the communication band required by the communication connection are declared to the request source. The control device stores the upper limit value and the lower limit value of the communication band and the current value of the communication band actually assigned for each communication connection that has been set, and the unused communication band has a new communication connection. If the lower limit of the communication band required in step 1 is insufficient, the communication band of the existing communication connections whose current value is larger than the lower limit is reduced within the range not lower than the lower limit.

However, a communication connection for which a new setting request is made is treated as a priority over other existing communication connections, and when the unused communication band is less than the upper limit value of the band requested by the new communication connection, The band of another existing communication connection may be reduced and the upper limit of the band may be assigned to the new communication connection. When the unused communication band satisfies the upper limit value of the communication band required for the new communication connection, the new communication connection is set with the requested upper limit communication band.

When it is preferable to express the required communication band by the quality level of information (moving image), such as moving image communication, the relationship between the value of the moving image level and the communication band is defined in advance. , When requesting the setting of the communication connection, the value of the video level is declared instead of the value of the communication band described above,
Convert the declared moving image level value to a communication band value and compare the unused communication band with the communication band required by the new communication connection, and the insufficient communication band due to the change of the communication band of the existing communication connection. May be supplemented.

Further, the priority is stored for each existing communication connection, and if the unused communication band is insufficient for the communication band required by the new communication connection, the priority of the existing communication connections The communication band may be reduced in order from the lowest communication connection.

[0012]

According to the communication control method of the present invention, even if the communication band is used by the existing communication connection and the remaining unused band is insufficient for the band for the newly requested communication connection, Since the shortage of unused bandwidth is compensated by reducing the bandwidth of the communication connection, new communication connection setting and information service using this communication connection become possible.

[0013]

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

FIG. 1 shows an example of the overall configuration of a communication system to which the present invention is applied. In the figure, reference numeral 1 is a communication network such as ISDN, and 10-1 and 10-2 are terminal devices which are connected to the communication network 1 and have a function of communicating with other terminal devices.

FIG. 2 shows an example of the configuration of the terminal device. In this terminal device, the moving image information input from the moving image input device 11 is encoded by the moving image encoding device 12 and then written in the memory 13 or the storage device 18. The moving image information stored in the memory 13 or the storage device 18 is read out under the control of the processor (CPU) 17 and sent to the communication network 1 via the communication control unit 14. The moving image information is sent to the partner terminal device connected by the communication connection.

On the other hand, the encoded moving image information transmitted from the partner device is received by the communication control unit 14 via the communication network 1 and written in the received image area of the memory 13 or a predetermined received image area of the storage device 18. Be done. The moving image information of the received image area is read out and supplied to the moving image decoding device 15 under the control of the CPU 17, and the decoded moving image information is combined with other screen information by the image combining device 16. After that, it is output to the display device 16.

The CPU 17 is connected via the internal bus 19 to the moving picture coding device 11, the moving picture decoding device 15, the communication control unit 14, the memory 13 and the storage device 18 described above, and various types stored in the memory 13. According to the program, the moving image communication control described later and other information processing operations are executed.

FIG. 3 shows the structure of the memory 13. 21,
Reference numeral 22 denotes an application program (such as a conference function or a mail function) that transmits / receives data information or moving image information via a communication connection established with another terminal device and outputs the transmitted / received information to a display device ( Hereinafter, in this specification, an application program having such a communication function is referred to as a communication program), 23 is a communication connection management unit (communication connection management program), and 24 is a table for managing the bandwidth of the communication connection. .

The communication connection management section 23 uses an unused communication band (marginal band) that can be allocated to a new communication connection on the communication connection management table 24.
And storing and managing information about the already set communication connection, when there is a request for setting a new communication connection from the communication program, or when there is a request for setting a new communication connection from another terminal device, It is judged whether the communication band required by the new communication connection can be secured with the above-mentioned margin band. If it cannot be secured, a part of the band of the already set communication connection is changed to a new communication connection. Perform allocation processing.

FIG. 4 shows a flow chart of a program routine which is one of the functions of the communication connection management unit 23 and which is executed when a communication connection control request is generated. When there is a communication connection control request, it is determined whether this connection control request is generated from any communication program of the terminal itself (step 30). If it is from the communication program of the own terminal, if it is a request for setting a new connection (step 3)
1), the communication connection setting process is executed (step 32), and if it is a release request for the already set connection (step 33), the communication connection release process is executed (step 34). Executes other processing according to the control request (step 3
5).

If the communication connection control request is from another terminal device (step 36), if it is a new connection setting request (step 37), the communication connection setting reception process is executed. If the request is to release the already set connection (step 39), the communication connection release reception process is executed (step 40), and if it is the communication band change request (step 41), the communication band is changed. Reception processing is executed (step 42), and if it is a moving image level change request (step 4)
3), the receiving process of the video level change is executed (step 4
4) If none of the above applies, other processing corresponding to the control request is executed (step 45).

FIG. 5 shows the communication connection management table 2
4 shows a configuration of an unused communication band management area 50 formed in FIG. In this area, the value of the marginal band (unused band) excluding the privately used band due to the connection setting is stored in the communication band allowed for the terminal.

FIG. 6 shows the configuration of the management area for the set communication connection information in the communication connection management table. This management area stores a plurality of records corresponding to each connection, and each record includes an identifier 51 for identifying each communication connection, a communication program name 52 using the communication connection, and a terminal device address 53 of the communication partner. And classification information 54 indicating whether the communication connection is used for video communication, and the current communication status 5
5, the priority 56 of the communication connection registered by the communication program, the upper limit value 57 of the band requested by the communication program to allocate to the communication connection, the lower limit value 58 of the band requested to be allocated to the communication connection by the communication program, and the communication The value (current value) 59 of the band currently allocated to the connection is included. In this embodiment, for the connection for video communication, the upper limit value of bandwidth is 5
7, the lower limit value 58 and the current value 59 are set to the moving image level values instead of the actual values of the communication band.

FIG. 7 shows a table showing the relationship between the moving image level, the coding level and the required communication band. This table defines the number of frames 61 per unit, the image quality 62, and the required communication band 63 corresponding to the moving image level 60. The moving image level is specified from the communication program for moving image processing. When there is a connection setting request,
The communication connection management unit 23 refers to the above table and converts it into the value of the required communication band.

FIG. 8 shows the structure of the moving picture coding apparatus 12. The moving image information input from the moving image input device 11 is encoded by the coder 71 and sequentially input to the first-in first-out queue (FIFO) 72. The encoded moving image information in the FIFO 72 is transferred to the internal bus 19 by the CPU 17.
Read out. Reference numeral 73 denotes an interface register for storing the data length of the encoded moving image information in the FIFO 72, flag information indicating whether the head of the outer FIFO is the beginning of the encoded moving image frame, and type information of the frame. Reference numeral 74 is an interrupt flag for generating an interrupt signal when there is a change in the status of the encoding process such as the occurrence of a processing error. By writing a request command in the command register 75, the communication program for moving image processing issues various control requests such as a request to change the encoding level to the processor 76 that integrally controls the encoding process.

FIG. 9 shows the structure of the moving picture decoding apparatus 15. Reference numeral 81 is a first-in first-out queue (FIFO) 81 for sequentially storing the encoded moving image information given via the internal bus 19, and 82 is the FIFOIO 81.
It is a length register 82 indicating the length of data (encoded moving image information) stored therein. 83 is FIFO8
1 is a decoder for decoding the coded moving image information extracted from No. 1 and outputting it to the image synthesizing device 16. The processor 86, which integrally controls the decoding process, sets flag information in the interrupt flag 84 and generates an interrupt signal when a change in the situation in the decoding process occurs, such as the occurrence of a processing error. The external user (program) issues various requests to the processor 86 by writing request commands in the command register 85.

FIG. 10 is a flow chart showing details of the communication connection setting process 32 shown in FIG. When a communication connection setting request is received from the moving picture processing communication program in the terminal device, it is judged whether or not the communication connection to be set is for moving picture communication (step 9).
3) If it is for moving picture communication, referring to the conversion table shown in FIG. 7, the communication band 63 corresponding to the moving picture level 60 designated by the communication connection setting request is generated.
Is calculated (step 94), and the necessary communication band is secured (step 95). If the communication connection to be set is not for moving image communication, the communication program performs the process for ensuring the communication band specified by the communication connection setting request (step 95). Details of the processing for securing the communication band will be described later with reference to FIG.

Next, it is determined whether or not the communication band has been secured (step 96). If the bandwidth can be secured in the communication bandwidth securing process (step 95), the value of the secured communication bandwidth is indicated by the parameter. If the required bandwidth is not secured, the requesting communication program is notified of the failure of the communication connection setting (step 9).
7). If the communication band is successfully secured, the value of the newly secured communication band is subtracted from the current value of the unused communication band in the unused communication band management area 50 formed in the communication connection management table 24. Is updated to a value indicating the remaining communication band (step 9).
8). In addition, in the management area of the already set communication connection information of the communication connection management table 24, the information about the communication connection for which the setting request is made this time is registered (step 99), and the value of the communication band to be secured is set for the partner device. A lower limit value is specified and a communication connection setting request is transmitted (step 100).

Waiting for a response to the above-mentioned communication connection setting request from the partner device (step 101), and when an affirmative response is given, the communication program of the request source is notified that the communication connection setting was successful (step 10).
2). If a negative response is received from the partner device, the registration information relating to the communication connection is deleted from the communication connection management table 24 (step 103), and the value of the unused communication band is set in the unused communication band management area. The value before the bandwidth of the connection is secured is returned (step 104), and the requesting communication program is notified that the setting of the communication connection has failed (step 97).

FIG. 11 is a flow chart showing the details of the communication band securing processing routine 95 in FIG. In the communication band securing processing routine, first, the unused communication band at the present time is obtained from the unused communication band management area in the communication connection management table 24 (step 11).
0), the value of the unused communication band is compared with the value of the communication band newly requested this time (step 111). If the unused communication band is larger than the upper limit of the communication band required by the new communication connection (including the case where it is equal),
The result parameter is set to a state indicating that the communication band has been successfully secured with the upper limit value. When the unused band is insufficient for the upper limit value but the lower limit value is satisfied, the result parameter is set to the value of the current unused band or to the state indicating that the communication band has been successfully secured at the lower limit value (step 112). .

If the unused communication band is smaller than the lower limit of the communication band required by the new communication connection, the communication band of another communication connection that has already been set is reduced, as described in detail in FIG. Processing is performed to increase the value of the unused communication band (step 113), and then the value of the unused communication band and the value of the requested communication band are compared again (step 114). If the unused communication band is larger (including the case where it is equal), the result parameter is set to a state indicating that the band can be secured with the value of the unused communication band (step 112), and if the unused communication band is smaller, Then, the result parameter is set to a state indicating that the communication band has not been secured (step 115), and the process returns to the original routine shown in FIG. It should be noted that the band securing notification may be performed with the lower limit value in the requested communication connection.

In the above embodiment, when the unused bandwidth is less than the lower limit value, the bandwidth reduction processing of the other communication connection is performed, but the new communication connection is requested over the other existing communication connection. When the bandwidth cannot be secured with the upper limit value (step 111), the bandwidth reduction processing 113 for another communication connection may be executed.

FIG. 12 is a flow chart showing the details of the communication band reduction processing routine 113 for another communication connection in FIG. First, as the initialization process, in order to carry out the communication band reduction process from the connection with the lower priority, the value of the search priority (parameter) for specifying the connection to be reduced is set to the lowest value (step 120). ), The data of the registered first record (first registration item) is read in the management area of the set communication connection information of the communication connection management table 24 (step 121), and the priority of the communication connection matches the search priority. Check whether to do (step 12)
2).

If they match, it is judged whether or not the communication connection is for moving picture communication (step 123),
For moving image communication, the current value 59 of the moving image level of the connection registered in the communication connection management table 24 shown in FIG. 6 is the lower limit value 58 of the moving image level.
It is determined whether or not it is larger (step 124), and if it is larger, in order to make up for the shortage of the communication band of the new communication connection requested this time, within a range not falling below the lower limit value 58 of the registered moving image level. Calculate new video level by lowering video level and communication bandwidth (step 125)
After that, the process for changing the moving image level of the connection, which will be described later with reference to FIG. 13, is performed (step 126). However, for simplicity, the new moving image level may be set as the moving image level lower limit value.

If the connection is not for moving image communication in the judgment step 123, the communication connection management table 24 is referred to and the current communication band value of the communication connection is compared with 59 and the lower limit value 58 ( Step 127). If the current value is larger than the current value, in order to compensate for the shortage of the communication band of the new communication connection requested this time, the communication band reduced within the range not lower than the lower limit of the above communication band is obtained (step 128), A process of changing the communication band of the connection, which will be described later with reference to FIG. 14, is performed (step 129). For simplification, the current value of the communication band may be reduced to the lower limit value of the communication band at once.

When these changing processes are completed, or when the priority of the communication connection does not match the search priority in step 122, or in steps 124 and 127, the current value of the moving image level or the communication band is lower than the lower limit value. If not, the unused communication band 50 is compared with the communication band (upper limit value or lower limit value) requested by the new connection (step 13).
0), if the unused communication band is larger, this routine ends.

If the unused communication band is insufficient, the communication connection targeted for the reduction processing is also the final data record (final registration item) registered in the communication connection management table 24. It is determined whether or not (step 130) and if it is not the final registration item,
The next data record (item) is read from the communication connection management table 24 (step 132), the process returns to step 122, and the same processing is repeated.

When the reduction processing target is the final data record (final registered item) in the judgment step 131, it is judged whether or not the current search priority (parameter) is the highest value (step 133). ), If it is the highest value, this routine is terminated, and if not, the value of the search priority parameter is increased by one level (step 134), and the process returns to step 121. In addition, when the priority is not given to the communication connection, steps 120, 122, 133, and 134 may be omitted.

FIG. 13 is a flow chart showing details of the moving image level changing process 26 in FIG. A moving image level change request is transmitted to the terminal device of the communication partner connected by the communication connection that has been changed, and a response from the partner device is awaited (step 140). When the response from the partner device to the moving image level change request is a negative response, a flag indicating that the change has failed is set in FIG.
The process returns to the original routine shown in 2 (step 142). If there is an affirmative response from the partner device, it is determined whether or not the video information is being transmitted (step 143). If the video information is not being transmitted, the process proceeds to step 146, and if the video information is being transmitted. , The transmission of the video information is interrupted (step 14
4) Request the moving picture coding device to change the coding level of the moving picture corresponding to the new moving picture level (step 1).
45).

When the process of changing the moving picture coding level is completed, it is judged whether moving picture information is being received (step 14).
6) If not being received, the process proceeds to step 149. If it is being received, the operation of receiving the moving image information is interrupted (step 14).
7) Request the video decoding device to change the video decoding level corresponding to the new video level (step 14).
8). When the moving picture decoding level changing process is completed, the communication connection is released (step 149),
The value of the unused communication band registered in the unused communication band management table is updated (step 150). here,
From the value of the communication band required at the video level before the change, subtract the value of the communication band required at the new video level,
This value is added to the value of the current unused communication band. When this is finished, the current video level registered in the communication connection management table is updated to the new video level (step 15).
1) Set a communication connection for transmitting / receiving the moving image information of the new moving image level (step 152).

If the moving image information is being transmitted (step 152), the moving image information transmitting operation is restarted (step 1).
53), if the video information is being received (step 1)
55), the operation of receiving the moving image information is restarted (step 15).
6). When the transmission / reception restart processing is completed, a flag indicating success in changing the moving image level is set, and the process returns to the original routine shown in FIG.

FIG. 14 is a flow chart showing the details of the communication band change processing routine 129 in FIG.
First, when a communication band change request is transmitted to the partner device (step 160) and a negative response to the communication band change request is received from the partner device (step 161), a flag indicating failure of the band change is set. Return to the original routine shown in 12. When an affirmative response is received, the data transmission / reception operation is interrupted (step 163), the communication connection is released (step 164), and the value of the unused communication band registered in the unused communication band management table is set. The value is updated (step 165). Here, the difference between the value of the communication band until then and the value of the new communication band is added to the value of the current unused communication band. When this is finished, the current communication band registered in the communication connection management table is updated to a new communication band (step 166), a communication connection having the new communication band is set (step 167), and data transmission / reception is restarted. After that (step 168), a flag indicating success in changing the communication band is set, and the process returns to the original routine shown in FIG.

FIG. 15 is a flow chart of the communication connection release processing routine 34 executed when a communication connection release request is received from the communication program.
When a communication connection release request is transmitted to the partner device (step 172) and a negative response to the release request is received from the partner device (step 173), the requesting communication program indicates that the communication connection release has failed. This is notified (step 174), and this routine ends. When a constant response is received from the partner device, the data of the communication connection registered in the communication connection management table is deleted (step 175) and the value of the unused communication band registered in the unused communication band management table is deleted. Is added to the value of the communication band used by the released communication connection (step 176), and the requesting communication program is notified that the communication connection has been released successfully (step 177). Exit the routine.

FIG. 16 shows a flowchart of the communication connection setting request reception processing routine 38 which is executed when a communication connection setting request is received from another terminal device.

In the communication connection setting request, the value of the communication band to be secured and the lower limit value thereof are designated. Steps 93 to 96 and steps 98 to 99 are the same as the flowchart shown in FIG. 10 executed when there is a communication connection setting request from the communication program in the own device. If the securement of the communication band fails in step 96, a negative response to the communication connection setting request is transmitted to the partner device (step 181), and this routine ends. If the communication band is successfully secured in step 96, the unused communication band management table is updated (step 98) and the connection is registered in the communication connection management table (step 99). , A positive response of the communication connection setting is transmitted (step 182), and this routine ends.

FIG. 17 shows a flowchart of the moving image level change request receiving process 44 executed when a moving image level change request is received from another terminal device. First, it is determined whether the requested new moving image level is higher than the current moving image level (step 192). If the new moving image level is lower, the process proceeds to step 143. If the new moving image level is higher, the new moving image level is set. After the value obtained by subtracting the communication band assigned to the current video level video communication from the communication band required for the video communication is set as the value of the communication band to be newly added (step 193), the communication band securing process ( Step 95)
And the success / failure check (step 96). Steps 95 to 96 are the same as those shown in FIG. If the securing of the communication band fails, the process proceeds to step 194, a negative response about the moving image level change is transmitted to the partner device, and this routine ends.

Steps 143 to 156 are the same as those shown in FIG. 13. After changing the coding level of the moving picture being transmitted and the decoding level of the moving picture being received in steps 143-148, the other party After sending an affirmative response to the device about the change of the moving image level (step 195), in steps 149 to 156, after releasing the communication connection, updating the table, setting a new communication connection, and restarting the moving image transmitting / receiving operation, this Finish the routine.

FIG. 18 is a flow chart showing the details of the communication band change request reception processing routine 42 which is executed when a communication band change request is received from another terminal device. First, it is determined whether or not the requested new communication band is larger than the current communication band (step 202), and if the new communication band is smaller, the process proceeds to step 163. If the new communication band is larger, the value obtained by subtracting the value of the current communication band from the value of the new communication band is set as the value of the communication band to be newly added (step 203) to secure the additional communication band. A process (step 95) and a success / failure check of band securing are performed (step 96). Steps 95 to 96 are the same as those shown in FIG. If the securing of the band fails, a negative response to the communication band change request is transmitted to the partner device (step 204), and this routine ends. Steps 163 to 168 are the same as those shown in FIG. 14, the data transmission / reception operation is interrupted in step 163, and an affirmative response of the communication band change request is transmitted to the partner device (step 205), and then steps 164 to 16
In step 8, the communication connection is released, the table is updated, the new communication connection is set, and the data transmission / reception operation is restarted.

FIG. 19 is a flow chart showing the details of the communication connection release request reception processing routine 40 which is executed when a communication connection release request is received from another terminal device. Steps 175-176 are the same as those shown in FIG. 15, and these steps 175-1
After updating the table at 76, an affirmative response to the communication connection release request is transmitted to the partner device (step 212), and this routine is ended.

FIG. 20 shows the nut of the control command for the communication connection. Reference numeral 220 is a communication header used by the communication control unit, and 221 is a communication connection management header used by the communication connection management unit. The communication band change request, the response to the communication band change request, the moving image level change request, and the moving image level are described above. Information indicating a command type such as a response to a change request is set.

Reference numeral 222 is an area in which various parameters required for each request / response are set. In the case of the request for changing the communication band and the request for changing the moving image level, as indicated by 223, a field 2 indicating the identifier of the communication connection
24 and a field 225 indicating a new communication band or moving image level after the change. If the command is a response, a code indicating positive or negative is set as indicated by 226.

According to the above-mentioned embodiment, even if the available communication band is small and the band required for a new communication connection is insufficient, it is possible to reduce the communication band of another communication connection that has already been allocated. Allows you to set up a new communication connection.

FIG. 21 is a flow chart of a routine executed by the communication connection management unit when it receives a request for changing the communication condition for a specific communication connection from the communication program of its own terminal. This routine is a part of the other processing 35 shown in FIG.

First, it is determined whether or not the communication connection is for moving picture communication (step 232), and if it is for moving picture communication, the current moving picture level is compared with the lower limit value of the moving picture level requested to be changed. (Step 233). If the current video level is lower, the lower limit of the video level requested to be changed is set to the new video level (step 2
34), subtracting the communication band required for the current moving image level from the communication band required for the new moving image level, and setting this as the newly required communication band (step 235),
The process of securing the communication band (step 95) and the success / failure check (step 96) are performed. Steps 95 to 96 above
Is the same as that shown in FIG.

If the communication connection is not for moving image communication, the current communication band is compared with the lower limit of the communication band requested to be changed (step 236). If the current communication band is smaller, The lower limit value of the communication band requested to be changed is set as the new communication band (step 237), the value of the current communication band is subtracted from the value of the new communication band, and this is set as the newly required communication band (step 238). Band securing processing is performed (step 95).

When the bandwidth is not secured in the communication bandwidth securing process, the requesting communication program is notified that the communication conditions have not been changed, and this routine is terminated.

If the above communication band is successfully secured,
If the communication connection is for moving image communication (step 239), the moving image level changing process (step 12)
6) is performed, and if the communication connection is not for moving image communication, communication band change processing (step 129) is performed.

In step 233, if the current moving picture level is not lower than the lower limit value of the moving picture level requested to be changed,
The current moving image level is compared with the upper limit value of the changed moving image level (step 240), and if the current moving image level is larger, the upper limit value of the changed moving image level is set to the new moving image level (step 241). ), The moving image level changing process (step 126) is performed.

If the current communication band is not smaller than the lower limit value of the changed communication band in step 236, it is judged in 242 whether the current communication band is larger than the upper limit value of the changed communication band. If larger, the new communication band is set in 243. The upper limit of the changed communication band is set, and the communication band changing process is performed at 129.

The moving image level changing process (126) and the communication band changing process (129) are the same as those shown in FIG. After these processes are executed, it is judged whether or not the change process is successful (step 244). If the change process is successful, the value of the communication condition of the communication connection is requested on the communication connection management table. The value of the communication condition is updated (step 245), the success of the change of the communication condition is notified to the requesting communication program (step 246), and this routine is ended.

When the current moving image level is not higher than the upper limit value of the moving image level requested to be changed in step 240, or when the current communication band is not higher than the upper limit value of the changed communication band in step 242, Similar to the above, steps 245 and 246 are executed, and this routine ends. If the change of the moving image level and the change of the communication band have failed (step 244), the communication program of the request source is notified that the change of the communication condition has failed (step 247), similarly to the case of failing to secure the communication band. ),
This routine ends.

FIG. 22 shows a flowchart of a routine executed by the communication connection management section when it receives a request (reservation) of a communication band from the communication program of its own terminal, as another embodiment of the present invention. In this embodiment, each communication program reserves (reserves) an unused communication band in advance, and the band change control can be performed within this communication band.

First, a process of securing a communication band (step 9)
5) is performed to judge whether or not the band is secured (step 9).
6). These steps 95 to 96 are the same as those shown in FIG. If you fail to secure the communication band,
The requesting communication program is notified of the failure to secure the communication band (step 254), and this routine ends. When the communication band is successfully secured, the unused communication band management table is updated (step 253), and the success of the communication band is notified to the requesting communication program (step 253), and then this routine is ended.

FIG. 23 shows the structure of the unused communication management table updated in step 252. In this embodiment, the value of the unused communication band is stored in association with the communication program name 260 that secures the communication band. Communication programs that have not made a request to secure a communication band are handled collectively under the program name “Other”.

The communication band previously reserved by the above-mentioned reservation request is, for example, steps 98 and 104 in FIG.
When updating the unused communication bandwidth management table in step 150 of FIG. 13, step 165 of FIG. 14, and step 176 of FIG. 15, the unused communication bandwidth management table is registered in correspondence with the communication program related to the communication connection. Update the unused communication band value for the existing value.

Also in the communication band securing process shown in FIG. 11, the unused communication band handled in steps 110, 111 and 114 is the unused communication band management table corresponding to the communication program related to the communication connection, as described above. The value registered in is targeted. Further, in the communication band reduction processing of FIG. 12, steps 121, 131, 1
When the registration item is read from the communication connection management table in 32, it is performed corresponding to the communication program related to the communication connection.

According to this embodiment, it is possible to flexibly allocate a bandwidth to a communication connection within the secured communication band without being affected by the communication connection set by another communication program.

[0068]

As is apparent from the above description, according to the present invention, when a request for setting a new communication connection is made, even if the unused communication band is insufficient, it is already set. By reducing the communication band in the communication connection of, it is possible to secure the required band,
It is possible to set a new communication connection.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a communication system to which the present invention is applied.

FIG. 2 is a diagram showing an example of a configuration of a communication terminal 10.

FIG. 3 is a diagram showing programs and tables prepared in a memory of a communication terminal.

FIG. 4 is a program flowchart showing the function of a communication connection management unit.

FIG. 5 is a configuration diagram of an unused communication bandwidth management table.

FIG. 6 is a configuration diagram of a communication connection management table.

FIG. 7 is a table configuration diagram showing a relationship among a moving image level, an encoding level, and a communication band.

FIG. 8 is a diagram showing a configuration of a moving image encoding device 12 in FIG.

9 is a diagram showing a configuration of a moving image decoding device 15 in FIG.

FIG. 10 is a communication connection setting process 32 in FIG.
The flowchart which shows the detail of FIG.

11 is a flowchart showing details of a communication band securing process 95 in FIG.

12 is a flowchart showing details of communication band reduction processing 113 in FIG.

13 is a flowchart showing details of moving image level changing processing 126 in FIG.

FIG. 14 is a flowchart showing details of communication band change processing 129 in FIG.

15 is a flowchart showing details of the communication connection release process in FIG.

16 is a flowchart showing details of a communication connection setting request reception process 38 in FIG.

17 is a video level change request reception process 4 in FIG. 4;
4 is a flowchart showing details of 4.

FIG. 18 is a communication band change request reception process 42 in FIG.
The flowchart which shows the detail of FIG.

19 is a flowchart showing details of the communication connection release request reception process in FIG.

FIG. 20 is a diagram showing the structure of a communication connection control command.

FIG. 21 is a flowchart of a routine executed by a communication connection management unit when a communication condition change request is received.

FIG. 22 is a flowchart of a routine executed by a communication connection management unit when a communication band securing request is received.

FIG. 23 is a diagram showing the configuration of an unused communication management table.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Communication network, 10-1 ... Terminal device, 95 ... Communication band securing process, 113 ... Other bandwidth reduction process.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H04M 3/00 B 8426-5K H04N 7/173 8732-5K H04L 11/20 103 A

Claims (11)

[Claims] 1. A communication control method for a communication system for setting a plurality of communication connections on a line having a predetermined communication band and performing a plurality of inter-program communication with another terminal device, When the unused communication band in the line is stored and a request for setting a new communication connection is made, if the unused communication band is insufficient for the communication band required for the new communication connection, any existing A communication control system characterized in that the new communication connection is set after reducing the communication band of the communication connection to compensate for the insufficient communication band. 2. A request for setting a new communication connection,
Have the requester declare the upper and lower limits of the communication band required for the communication connection, and set the upper and lower limits of the communication band for each configured communication connection and the current value of the communication band actually assigned. If the unused communication band is insufficient for the lower limit value of the communication band required for the new communication connection, the existing communication connections are The communication control system according to claim 1, wherein the communication band is reduced within a range not lower than the lower limit value. 3. A request for setting a new communication connection,
Have the requester declare the upper and lower limits of the communication band required for the communication connection, and set the upper and lower limits of the communication band for each configured communication connection and the current value of the communication band actually assigned. If the unused communication band is insufficient for the upper limit value of the communication band required for the new communication connection, the existing communication connections are The communication control system according to claim 1, wherein the communication band is reduced within a range not lower than the lower limit value. 4. When the unused communication band satisfies the upper limit value of the communication band required for the new communication connection, the new communication connection is set in the communication band of the upper limit value,
The new communication connection is set in the unused communication band or the communication band of the lower limit value when the unused communication band is insufficient for the upper limit value but satisfies the lower limit value. 2. The communication control method described in 2. 5. A relationship between a moving image level value indicating a moving image quality and a communication band is defined in advance, and when the newly requested communication connection is for moving image communication, the value of the communication band is replaced with the value. The value of the moving image level is declared, the value of the declared moving image level is converted into the value of the communication band, and the comparison process between the unused communication band and the communication band required by the new communication connection, and the existing The communication control system according to any one of claims 1 to 4, wherein supplementary processing of the insufficient communication band is performed by changing the communication band of the communication connection. 6. A priority is stored for each existing communication connection, and if the unused communication band is insufficient for the communication band required by the new communication connection, the priority of the existing communication connections The communication control system according to claim 1, wherein the communication band is to be reduced in order from the lowest communication connection. 7. A communication control method for a communication system for setting a plurality of communication connections on a line having a predetermined communication band and performing a plurality of inter-program communication with another terminal device, The unused communication band in the line is stored, and when there is a request for setting a new communication connection, if the unused communication band is short of the communication band required for the new communication connection, the above-mentioned shortage occurs. In order to supplement the communication band, the communication band is reduced in any of the existing communication connections, and the terminal device as the communication partner is requested to change the communication band for the communication connection targeted for the above reduction. Regarding the above-mentioned communication control, the new communication connection is set after the communication band is reduced in both terminal devices. Method. 8. A request for setting a new communication connection,
Have the requester declare the upper and lower limits of the communication band required for the communication connection, and set the upper and lower limits of the communication band for each configured communication connection and the current value of the communication band actually assigned. If the unused communication band is insufficient for the upper limit value of the communication band required for the new communication connection, the existing communication connections are The communication control method according to claim 7, wherein the communication band is reduced within a range not lower than a lower limit value. 9. A request for setting a new communication connection,
Have the requester declare the upper and lower limits of the communication band required for the communication connection, and set the upper and lower limits of the communication band for each configured communication connection and the current value of the communication band actually assigned. If the unused communication band is insufficient for the lower limit value of the communication band required for the new communication connection, the lower limit value of the existing communication connections whose current value is larger than the lower limit value is stored. The communication control method according to claim 7, wherein the communication band is reduced within a range not less than the above. 10. If the unused communication band satisfies the upper limit value of the communication band required for the new communication connection, the new communication connection is set with the communication band of the upper limit value, and the unused communication band is The communication control method according to claim 9, wherein when the upper limit value is insufficient but the lower limit value is satisfied, the new communication connection is set in the unused communication band or the communication band of the lower limit value. 11. A priority is stored for each existing communication connection, and if the unused communication band is insufficient for the communication band required by the new communication connection, the priority of the existing communication connections The communication control method according to any one of claims 7 to 10, wherein the communication band is to be reduced in order from the lowest communication connection.