JPH03272248A - Digital communication system - Google Patents

Abstract

PURPOSE:To realize a variable band allocation system and equipment able to use a proper network resource by providing a means designating a call originating and a call incoming terminal equipment band through the use of request band information form the call originating terminal equipment, request band information from the call incoming terminal equipment, and allocation enable band information of a digital communication network. CONSTITUTION:A CPU 25 recognizes a current cell transmission quantity while monitoring a cell generation/separation section 23 at all times and sends request band information to a digital communication network 3 in the case of making communication. Upon the receipt of a call setting message from a network 3, a call incoming terminal equipment TE 2 decides whether itself makes variable communication or fixed communication. In the case of the variable communication, allocation enable band information beta is decided as operating band information gamma and a message is sent to the network 3. When the allocation enable band information beta is larger than the request band information alpha of the call incoming terminal equipment TE 2, the request band information alphais decided as the operating band information gamma and a message is sent to the network 3.

Description

[Detailed Description of the Invention] [Summary] Regarding a variable bandwidth allocation method for available bandwidth when performing variable bandwidth communication between a comprehensive digital integrated broadband service network and terminal devices connected thereto, appropriate network resources are provided. With the aim of providing a variable bandwidth allocation method that enables the use of TE, the digital communication network side that receives the requested bandwidth information requested from the terminal equipment, in the communication system that allocates the communication band, requested bandwidth information requested by the receiving terminal device TE,
Bandwidth specifying means for specifying band information of the originating terminal device TE and the destination terminal device TE based on allocatable bandwidth information grasped by the digital communication network side, and monitoring the amount of communication traffic on the digital communication network side. and includes a used band changing means that notifies the changed band when the band status changes, and when the originating terminal device TE and the destination terminal device TE are communicating via the digital communication network, the communication band known to the network side is provided. When there is a change in the communication band, the used band changing means notifies the originating terminal device TE and the destination terminal device TE of the change in the communication band.

[Industrial application field]

The present invention relates to a variable bandwidth allocation system for available bandwidth when performing variable bandwidth communication between a broadband service comprehensive digital communication network and terminal devices connected thereto.

In recent years, with the spread of data communications, not only conventional voice but also important data has come to be communicated using public lines, and future communication networks will require high-quality transfer and exchange. It is currently attracting attention as a network for communication services that can provide not only 64 Kb/s audio and low-speed data, but also high-speed data of about 150 Mb/s for TV-like moving images and high-definition TV. Broadband Service Comprehensive Digital Integrated Network (hereinafter referred to as B)
-ISDN(: Broadband -Integr
ated 5 services, DigitalNetw
ork) has reached the practical stage, and various interfaces are being standardized. Unlike conventional switching methods, BTSDN uses asynchronous transfer mode (hereinafter referred to as AT).
M(:85ynchronousTransfer M
(referred to as ode)), information of different speeds such as audio, low-speed data, and moving images can be handled in the same way. In other words, in an ATM network, information in different bands is transferred and exchanged while being accommodated in units of a fixed length called cells to distinguish them from conventional packet communications.

In this ATM, each time communication information is generated, a cell (ATM
The VBR (information transfer unit) that generates and transfers the information transfer unit (
Variable Bit Rate) communication, and CBR (Constant Bit Rate) communication, which periodically transfers cells regardless of the presence or absence of information like in conventional communication.
) There is communication.

FIG. 7 is a diagram showing a communication image, and (a) in the figure shows C
An image of BR communication is shown, and (b) of the same figure shows an image of VBR communication. In the figure, a transmission slot regularly allocated to a subscriber is composed of a plurality of cells, and the total number of cells is the maximum amount of transmission information that can be transmitted at one time. In the CBR communication shown in FIG. 7(a), since 12 cells are always transferred at regular intervals such as t1 to t4,
The amount of information transmitted per unit time is constant, and traffic management on the network side can be handled in the same way as with conventional circuit switching technology.

On the other hand, in the VER communication shown in FIG. 7(b), the interval at which cells are transferred is irregular due to the communication principle described above, and when the amount of information is large as in t8, multiple cells are transferred per unit time corresponding to the amount of information. For example, 19 cells may be sent, or if there is no amount of information per unit time, no cells may be sent at all as in t6. For this reason, the bandwidth of transmitted information is not constant even during communication, and for example, the maximum value is 150 Mb.
It can accommodate fluctuations such as a minimum value of 30 Mb/s and can efficiently accommodate moving image information and the like in which the amount of communication information changes greatly. Furthermore, since line data and packet data are multiplexed on a cell-by-cell basis without distinction, different data can be transferred flexibly and transmission paths can be used efficiently, so it is expected to be a future communication method. Such a terminal performs processing such as regulating waiting when a large amount of data is to be transmitted, or thinning out processing data of an encoding circuit that processes the signal in the case of image data.

[Conventional technology]

FIG. 8 is a diagram showing a conventional call setup processing sequence. -Terminal device TEI used in VBR communication for boat fishing,
TE2 can roughly recognize the amount of bandwidth used according to the transmission content, and notifies network 3 of the bandwidth information (maximum value, average value, etc.) to be used when setting up a call.On the other hand, network 3 It grasps the situation and determines whether the request from the terminal device TE is in an acceptable band.Since the network side handles input information from five different terminal lines, the band of the request from a certain terminal is wJ3. If the bandwidth exceeds the allocatable bandwidth, the communication is determined to be impossible (NG) and the terminal device making the request is notified of the inability to communicate.

The terminal device that receives this notifies the network 3 of information (maximum value, average value, etc.) about the bandwidth to be reused for a certain period of time.

If the requested bandwidth is within the Wi3 allocable bandwidth, communication is possible (
OK) and call setup (SE
TUP) Send a message ■″.

The terminal device TE2 determines whether or not to accept this communication, and if it is in a state where it can be accepted, it sends a response to the terminal device (C
ONN) Send a message ■″, ■″. If acceptance is not possible, a disconnect (Disc) message will be sent.

Following the above steps, the line will be connected and communication will be possible.

[Problems to be Solved by the Invention] In this conventional configuration, if the bandwidth requested by the terminal device TE1 at the time of call setup is larger than the bandwidth allowable on the network 3 side, the communication is not accepted and the connection is disconnected.

Therefore, communication cannot be performed until the allowable bandwidth on the network 3 side satisfies the required bandwidth, and the terminal equipment must make repeated calls until the bandwidth is allowed. Invalidation processing will also be applied to the third side.

Furthermore, when the terminal device TE1 cannot communicate in the required band, there is a disadvantage that communication is not allowed even if communication is desired even if the communication quality is temporarily lowered.

Furthermore, even if communication is allowed and communication is started between the terminal devices TEI and 2, it is not allowed to change the communication band due to traffic fluctuations on the network side, and the availability of resources such as communication lines on the network side is not allowed. There was a problem that it could not be used effectively.

The present invention solves this problem and aims to provide a variable bandwidth allocation system and device that enables appropriate use of network resources.

[Failure to solve the problem]

FIG. 1 is an explanatory diagram of the principle of the present invention, and shows a schematic diagram of the configuration of a wideband service comprehensive digital communication system. In the figure, ■, 2 is a terminal device TE of ISDN capable of VER communication, and 3 is a B-1 SDN network.

4 is a band specifying means within 13-ISDN, which specifies the received requested band information α and currently available allocatable band information β.
The used band information T used for communication is determined from the above.

Reference numeral 5 denotes a used bandwidth monitoring means, which monitors the current amount of used bandwidth within the terminal device.

Reference numeral 6 denotes a used band determining means, which determines the received used band information T.
57 is a bandwidth changing means that determines the bandwidth information (γ) to be used for communication based on the required bandwidth information θ of the own terminal device. Send the changing bandwidth amount ε.

The first feature of the present invention is that the requested bandwidth information α requested from the originating terminal device TEI, the requested bandwidth information θ requested from the receiving terminal device TE2, and the allocatable bandwidth information β grasped by the digital communication network 3 side , the originating terminal device TEI
and a band specifying means 4 for specifying a communication band γ between the destination terminal device TE2 and the destination terminal device TE2.

The second feature is that the digital communication network 3 side is equipped with a used band changing means 7 that monitors the amount of communication traffic and notifies the changed band when the band status changes, and the originating terminal device TEI and the destination terminal device TE2 During communication via the digital communication network 3, when there is a change in the communication band known to the network side, the use band changing means 7
1 and the destination terminal device TE2 are notified of the change in communication band.

A third feature is that the originating terminal device TEI is provided with a used bandwidth monitoring means 5 for monitoring the current amount of used bandwidth; The point is that the maximum value α of is added to the call setting signal and sent to the digital communication network 3.

A fourth feature is that the called terminal device TE2 is provided with a used band determining means 6 for determining the used band information ζ to be used for communication from the received allocatable band information δ and the required band information θ of the own terminal device. When the allocatable bandwidth information δ is received from the digital communication network 3, the usable bandwidth determining means 6 determines the usable bandwidth information ζ to be used for communication from the requested bandwidth information θ of the own terminal device.

[For production]

In the present invention, when setting up a call, the terminal equipment sends the maximum amount of bandwidth to be used for communication to the network 3 as requested bandwidth information α. The network 3 receives the requested bandwidth α, compares it with the available bandwidth information β that can be currently provided for communication, and determines the available bandwidth information γ.

The other terminal device TE2 receives the allocatable bandwidth information γ1 2 , compares it with the requested bandwidth information θ of its own terminal device, and determines the used bandwidth information ε.

Also, if there is a change in the band status of 8M3 during communication,
This band change amount ζ is calculated by both terminal devices TE2. Send to TE2. Then, the communication band between the terminal equipment and the TE 2 can be changed in accordance with the fluctuation of the network side band.

〔Example〕

FIG. 2 is a configuration diagram of an embodiment of a terminal device. In the figure, information data from an information generation unit 21 and control information from a D channel control unit 22 are packed into packets called cells by a cell generation/separation unit 23 and sent to a network via a line accommodation unit 24.
sent to. The CPU 25 is always connected to the cell generation/separation unit 23
The network 3 recognizes the current cell transmission amount while monitoring the current cell transmission amount, and causes the network 3 to transmit requested bandwidth information when performing communication.

FIG. 3 shows a configuration diagram of an embodiment of ATM communication nodes that constitute an I5DN network. Generally, TSDNfi is the third
It is composed of a plurality of ATV communication nodes shown in the figure.

In the figure, 31 is a line accommodating unit that accommodates the line from the terminal;
2 is an incoming cell number monitoring function that monitors the traffic volume of the ATM communication node; 33 is an intra-network traffic monitoring/management function unit that manages the traffic volume of the entire 15DNl; and 34 is a multiplexing cell unit that outputs the multiplexed cells to the destination line. A.T.
M exchange function section, 35 line accommodation sections for accommodating connection lines between nodes, 36 a CPU, and 37 a memory.

The requested bandwidth information α included in the call setup message from the terminal device TE is received by the line accommodation section 31. Then, the incoming cell number monitoring function section 32, which constantly monitors the current traffic amount, transmits this requested bandwidth information α to the intra-network traffic monitoring/management function section 33. Is it possible for the intra-network traffic monitoring/management function unit 33 to receive the allocatable bandwidth from the incoming cell count monitoring function 32 provided for each ATM communication node, and to accept the bandwidth requested by this terminal device TE? to judge. The method for this determination will be described below. Now, cells from the terminal 3 4 device TE in the communication state are switched by the ATM exchange function unit 4, multiplexed for each destination line, and asynchronously sent to the inter-node connection line via the line accommodation unit 35. be done. In this way, it is connected to the communication partner terminal device TE2 via a plurality of nodes.

FIG. 4A is a diagram showing a processing flow when a call is set up by the calling terminal device, and FIG. 4B is a diagram showing a processing flow when a call is set up by the network 3.
FIG. 4C is a diagram showing the processing flow when a call is set up by the receiving terminal device. # symbols in the figure indicate input/output between devices.

The processing flow when setting up a call will be explained below.

In FIG. 4A, when transmission information is generated, the originating terminal device TEI determines whether to communicate using fixed communication or variable communication (step 400). When fixed communication is used (NO in step 400), fixed requested bandwidth information BWO is set (step 401). and,
It is sent to #1 of network 3 in a call setup (SETUP) message (step 402).

When performing variable communication (YES in step 401), depending on the type of information to be sent (e.g. audio, data video),
A predetermined usage bandwidth (for example, the maximum value) is set as the requested bandwidth information BWO (step 403), and call setup (SETU) is performed.
P) Transmit the message to #l of network 3 (step 404).

In FIG. 4B, when the 8N3 receives this call setup (SETUP) message from the originating terminal device TE1 (step 405), the requested bandwidth information BWO is compared with the allocatable bandwidth information BWI, which is the allocatable band of the network 3. (Step 406).

When the requested bandwidth information BWO is larger than the allocatable bandwidth information BW1 and the originating terminal device requests fixed communication (No in step 407), a disconnection (DISC) message indicating that the request cannot be accepted because it is not permissible is sent. is returned to terminal device #4 (step 408).

When the requested bandwidth information BWO is larger than the allocatable bandwidth information BW1 and the originating terminal device TE requests variable communication (YES in step 407), the allocatable bandwidth information BWI is transmitted to the communication partner end 56. It is sent to #2 in a call setup (SETUP) message to device TE2 (step 409).

On the other hand, the requested bandwidth information BWO is better than the allocatable bandwidth information BW.
I, and when the originating terminal device requests fixed communication (NO in step 410), the requested bandwidth information B
The request for fixed communication in WO is sent to the # of the destination terminal device TE2.
2 (step 411).

When the requested bandwidth information BWO is smaller than the allocatable bandwidth information BW1 and the originating terminal device TEI requests variable communication (YES at step 410), the requested bandwidth information B
The WO is used as the requested bandwidth information and sent to #2 in a call setup (SETUP) message to the communication destination terminal device TE2 (step 412).

In FIG. 4C, the called terminal equipment TE2 receives a call setup (SETUP) message from the network 3 (step 41).
3), the own terminal determines whether to perform variable communication or fixed communication (step 414).

When both the originating terminal device and the terminating terminal device TE2 are in variable communication (YES in step 415), the allocatable bandwidth information BWO or BWI from the network 3 is compared with the requested bandwidth information BW2 of the terminating terminal device TE2 (step 416). ). Then, when the allocatable bandwidth BWO or BWI is smaller than the requested bandwidth information BW2 of the receiving terminal (YES in step 416),
S) Step 417: Determine the available bandwidth information BWO or BWI as the used bandwidth information BW3, and send a response (CONN) message with this BW3 to #3 of the network 3.
). On the other hand, when the allocatable bandwidth information BWO or BWI is larger than the requested bandwidth information BW2 of the receiving terminal device TE2 (NO in step 416), the requested bandwidth information BW2 is determined as the used bandwidth information BW3, and this BW3 is assigned to #3 of the network 3. Send a response (CONN) message with (Step 4)
18).

When the originating terminal device TEI is in fixed communication mode and the terminating terminal device TE2 is in variable communication mode (NO in step 415), allocatable bandwidth information BWO and requested bandwidth information BW2 are compared (step 419). Then, when the allocatable band information BWO is smaller than the requested band information BW2 of the receiving terminal device TE2 (YES at step 420), the allocatable band information BWO is determined as the used band information BW3, and this BW3 is assigned to #5 of the network 3.
A response (CONN) message is sent (step 420). On the other hand, when the allocatable bandwidth information BWO is larger than the requested bandwidth information BW2 of the receiving terminal device TE2 (NO at step 419), a disconnection (DISC) message indicating refusal of reception of fixed communication called the allocatable bandwidth information BWO is sent to the # of the network 3. 5 (step 421).

When the originating terminal device TEI uses variable communication and the receiving terminal device TE2 uses fixed communication (YES at step 422), the allocatable bandwidth information BWO or BWI is compared with the requested bandwidth information BW2 (step 423).

Then, when the allocatable bandwidth information BWO or BWI is smaller than the requested bandwidth information BW2 of the receiving terminal TE2 (YES in step 423), the fixed communication with the requested bandwidth information BW2 cannot be accepted, so a disconnection (DISC) message is sent to the network. 3, #3 (step 424). on the other hand,
The allocatable bandwidth information BWO or BWI is sent to the receiving terminal device TE.
2 (step 42).
3: No), the requested bandwidth information BW2 is used as the used bandwidth information BW3
Finally, step 425), this BW3 is added to #3 of network 3.
Sends a response (CONN) message with .

When both the originating terminal device TEI and the receiving terminal device TE2 are in fixed communication (No in step 422), it is determined whether the allocatable bandwidth information BWO and the requested bandwidth information BW2 match (step 426). If they are equal (YES in step 426), the requested bandwidth information BWO is determined as the used bandwidth information BW3 (step 427), and a response (CONN) message carrying this BW3 is transmitted to #5 of the network 3. On the other hand, if they are not equal (No in step 426)
, and sends a Disc message (step 428).

In this way, the called terminal device TE2 uses the usage band 9. 0 Determine area information BW3.

In FIG. 4B, when the originating terminal device TEI is variable communication, the network 3 receives usage band information BW from the terminating terminal device TE2.
A response (CONN) message containing a 3 or a disconnection (DI
SC) When the message is received (step 429), the message is sent as is to #6 of the originating terminal device TEI (step 430). On the other hand, the originating terminal device TEI
When is a fixed communication, a response (CONN) message or a disconnection (DISC) message containing the used band information BW3 is received from the receiving terminal device TE2 (step 43).
1) and the above message as is on the sending terminal device.
4 (step 432).

In FIG. 4A, the terminal equipment is connected to the network 3 during the variable communication state.
response (CONN) message or disconnection (DIS) from
C) When a message is received (step 433), it is determined which message was received (step 4
34).

When a disconnection (DISC) message is received (YES in step 434), communication is abandoned (step 43).
5).

When a response (CONN) message is being received (NO in step 434) and when the other party's terminal is in variable communication (YES in step 436), the used band information BW
In '3, variable communication is performed (step 437). On the other hand, when a response (CONN) message is being received (NO in step 434), and when the other party terminal uses fixed communication (No in step 436), fixed communication is performed using the usage band information BW3 (step 438). .

If the terminal device TEI receives a response (CONN) message or a disconnection (DISC) message from the network 3 during the fixed communication state (step 439), it is determined which message was received (step 440).

If a disconnection (DISC) message is received (YES in step 440), communication is abandoned (step 4).
41).

When a response (CONN) message is received (NO in step 440), fixed communication is performed in the used band BW3 (step 442).

Call setup is performed using the processing flow described above.

FIG. 5 is a diagram showing a processing flow for changing the band status during communication. During communication, the band status BW3 of the network 3 is the band status BW.
4 (step 500), the band change information B
Notify W4 to terminal devices TEI and TE2 (Step 5
01). Terminal device TE1. ．． When the TE2 receives the notification of the band change (steps 502, 503), the requested band change information BWO', BWI' currently requested by its own terminal device is sent to the TE2.
is sent to network 3 (steps 504, 505).

When Part 3 receives the requested bandwidth information BWO' of the terminal device and the requested bandwidth change information BWI' of the terminal device T'E2 (step 506), Part 3 receives the requested bandwidth change information BWO' received from the terminal devices TE1 and TE2. ' and BWI' are compared (step 507).

If the requested bandwidth change information BWO' from the terminal device TEI is smaller than the requested band change information BW1' from the terminal device TE2 and smaller than the band change information BW4 (YES in step 508), the band change from this terminal device is performed. Step 5: Change the information BWO' to the used band change information BW5.
09), sends an INFO message containing this BW5 to both terminal devices TEI and TE2 (step 510).
).

On the other hand, if the requested bandwidth change information BWO' from the terminal device is smaller than the requested band change information BWI' from the terminal device TE2 and larger than the band change information BW4 (NO in step 508), the band change information of the network 3 BW4 is set as the used band change information BW5 (step 511), and an INFO message carrying this BW5 is sent to both terminal devices TE1 and TE2 (step 510).

If the requested bandwidth change information BW1' from the terminal device TE2 is smaller than the requested band change information BWO' from the terminal device TEI and smaller than the band change information BW4 (YES in step 512), the band change from this terminal device TE2 is performed. The information BWI' is used as the band change information BW5 (step 513), and an INFO message carrying this BW5 is sent to both terminal devices TEI and TE2 (step 510).

If the requested band change information BWI' from the terminal device TE2 is smaller than the requested band change information BWO' from the terminal device TE1 and larger than the band change information BW4 (No in step 512), the band change information BW4 of the network 3 is Step 514L sends an INFO message carrying RKBW5 to both terminal devices and TE2 as used band change information BW5 (step 510).

The terminal equipment, TE2, receives this used band change information BW5 (steps 515, 516), and thereby changes this BW5.
Enter the communication state with W5 (steps 517, 51
8).

FIG. 6 is a diagram showing an embodiment of the present invention, and shows a control sequence during call setup and communication.

Consider a case where the terminal device transmits band BWO information to the terminal device TE2.

First, the terminal device TEI sends a call setup (SETUP) message to the network 3. This call setup message is a CBR
The message includes the type of communication indicating communication or VBR communication, requested bandwidth information BWO1 indicating the maximum requested bandwidth, and information indicating that the available bandwidth can be changed.

Network 3 that received this call setup (SETUP) message
is a call setting reception (CALL PROC) to the terminal equipment.
■ Return the message. Line 3 includes allocatable bandwidth information BWI indicating the current available bandwidth recognized by network traffic monitoring/management function 33 and terminal device TE1.
The requested bandwidth information BWO from
The allocatable bandwidth information BWO or BWI is determined by the processing from step 05 to step 412. Then, this allocatable bandwidth information BWO or BWI is sent to the terminal device TE2 in a call setup (SETUP) message to the terminal device TE2.

When the terminal device TE2 receives the call setup (SETUP) message, it returns the ALERT message 2!16- to the terminal device. The terminal device TE2 is the fourth
In the processing from step 413 to step 428 in Figure C, it is determined whether communication is to be performed by VER communication or CBR communication, and used band information BW3 is determined. Then, messages (CONN, REL, RE
L COM.

■ Return any of the DISCs. When sending a response (CONN) message, it carries information such as the communication type indicating whether the receiving side is CBR communication or VBR communication, the determined usage band information BW3, and information indicating whether the usage band can be changed.

The network 3 receives the response (CONN) message and recognizes the communication type and used band information BW3. Then, this response (CONN) message is directly notified to the terminal device TEI.

The terminal equipment receives the received response (CONN) message, recognizes the communication type and the used band information BW3, and enters a communication state under these conditions. Then, a response confirmation (CONN ACT) message indicating the connection is sent back to the terminal device TE2.

The terminal device TE2 also receives a response confirmation (CO) from the terminal device TEI.
NN ACT) By receiving the message, the response (
CONN) Enters the communication state under the conditions included in the message.

Next, let us consider the processing flow for changing the bandwidth when the line connection is VBR communication and variable designation is made.

The congestion state of network 3 is constantly changing, and now consider a case where the allocatable bandwidth of navy blue 3 changes from BW3 to BW4.

In step 501 of FIG. 5, the network 3 puts the band change information BW4 into the INFO message and sends it to each terminal device TEI, T
■' Notify E2.

Each terminal device TEI and TE2 that received this received the message! Input each requested bandwidth change information BWO', BWl' to A3.
■', ■' The network 3 performs the processing from step 506 to step 510 in FIG. 5 and receives the received requested bandwidth change information BWO', BWI.
' is used to determine the usage change band information BW7 8 5. Then, this use change band information BW5 is put in the INFO message, and the terminal devices TEl and TE2
■' to be sent to.

y13 sends the BW5 determined here to the network traffic monitoring/management function 33 to each terminal device TEl, TE2.
is set to MM26.

In this way, the allocatable bandwidth information can be changed in response to changes in the traffic situation of the network 3 even during the communication state.

In addition, when the terminating terminal equipment TE2 side wants to know the requested bandwidth of the originating terminal equipment during call setup, the network 3 sends the requested bandwidth information of the originating terminal equipment and the allocatable bandwidth information of '1iii3 to the terminating terminal equipment. The notification may be sent to the device TE2.

In order to notify the terminal device TE side of the allocatable band,
Even when sufficient bandwidth is not secured, communication can be performed using the minimum allowable bandwidth, and unnecessary call setup operations with the network side are eliminated.

Second, even if sufficient bandwidth is not allocated to the terminal device TE at the time of call setup, there is a possibility that sufficient bandwidth can be secured during communication due to subsequent changes in network conditions.

Thirdly, from the network side, it can be used as a means to reduce traffic during communication during congestion, thereby making it possible to quickly return to the normal state during congestion.

Fourthly, from the terminal device TE side, it is possible to know the changing state of the network band, which was not known before, so that the allocated band can be easily changed.

〔Effect of the invention〕

As described above, according to the present invention, it becomes possible to use available bandwidth flexibly and effectively in response to changes in network conditions in B-ISDN.

For this reason, firstly, when setting up a call, the network assigns

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a block configuration diagram of a terminal device according to the present invention. FIG. Figure 4B shows the processing flow of the device (when setting up a call), Figure 4B shows the processing flow on the network side (when setting up a call), Figure 4C shows the processing flow of the receiving terminal (when setting up a call), and Figure 5 shows the band status during communication. FIG. 6 is a diagram showing an embodiment of the present invention. FIG. 7 is a diagram showing a communication image. (a) An image of CBR communication (b) An image of VER communication FIG. This is a conventional process sequence when setting up a call. The main parts in Figure 1 are as follows. 1... Terminal device TE 2... Terminal device TE 3... Digital communication network 4... Bandwidth specifying means 5... Bandwidth monitoring means Bandwidth determining means Bandwidth changing means Requested bandwidth information network for the device Allocatable bandwidth information determined by the allocatable bandwidth information network of area information TE2) 1 (Used bandwidth information determined by the allocatable bandwidth information terminal device TE2 from the requested bandwidth information network of area information TE2)

Claims (1)

[Claims] 1. In a communication system in which the digital communication network (3) side that receives the requested bandwidth information requested from the terminal device allocates the communication band, the requested bandwidth information requested from the originating terminal device TE (1). information(
α), requested bandwidth information (θ) requested from the terminating terminal device TE (2), and allocatable bandwidth information (β) grasped by the digital communication network (3) side, the originating terminal device T
Bandwidth information (
A digital communication system characterized by comprising a band specifying means (4) for specifying γ). 2. In a communication system where the digital communication network (3) receives the requested bandwidth information requested from the terminal device and allocates the communication band, the digital communication network (3) side monitors the amount of communication traffic and informs the digital communication network (3) of the band status. It is equipped with a used band changing means (7) that notifies a changed band at the time of change, and when the originating terminal device TE (1) and the destination terminal device TE (2) are communicating via the digital communication network (3), the network When there is a change in the communication band that is known to the user, the use band changing means (7) causes the originating terminal device TE (1) and the destination terminal device TE (2) to change the communication band. A digital communication system characterized by notifying. 3. The originating terminal device TE (1) is provided with a used bandwidth monitoring means (5) for monitoring the current amount of used bandwidth, and the originating terminal device TE (1) monitors the used bandwidth monitoring means (5) at the time of call setup.
5) The calling side of the digital communication system according to claim 1 or 2, wherein the maximum value (α) of the amount of bandwidth to be used is added to the call setting signal and sent to the digital communication network (3). Terminal device. 4 In the destination terminal device TE (2), a usable bandwidth determining means for determining the usable bandwidth information (ζ) to be used for communication from the received allocatable bandwidth information (δ) and the required bandwidth information (θ) of the own terminal device. (6) is provided, and when the allocatable bandwidth information (δ) is received from the digital communication network (3), the usage bandwidth determining means (6) determines the bandwidth to be used for communication based on the required bandwidth information (θ) of the own terminal device. The receiving terminal device of a digital communication system according to claim 1 or 2, characterized in that the used band information (ζ) is determined.