JPH0385045A - Terminal equipment - Google Patents

Abstract

PURPOSE:To prevent useless transmission by starting the transmission based on the detected operating state of a B-channel. CONSTITUTION:An operation panel 7 is operated to receive a call setting command. A main control section 8 sends a call setting message SET to a bus 13 through a B-channel via a transmission section 1. The message SET is sent to an ISDN line 12 via a DSU 11. A line use detection section 6 detects a call setting reception message and a reply message from the D-channel on the bus 13, informs them to the main control section 8 to start the transmission control of picture information. Since either of the two B-channels of the line 12 is designated by a reception message, the control section 8 discriminates it that the designated B-channel is usable and which of scanner transmission and memory transmission is to be designated is discriminated by a panel 7. In the case of the scanner transmission to be designated, a scanner section is started to command the transmission of the picture information to the transmission section 1 and the transmission section 1 sends the picture information to the usable B-channel. Thus, useless transmission is not repeated and sure transmission is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a terminal device connected to a line of a digital integrated service network.

(Prior Art) FIG. 5 illustrates a connection mode between a line of a digital integrated service network (hereinafter referred to as 15DN) and a terminal device. In the figure, a digital line terminal unit (hereinafter referred to as DSU)
11 is the l5DN line (hereinafter referred to as the SDN line) 12
and the bus 13 as an interface.

Each terminal device 14-1 to 14-8 is connected to the bus 13. The 15DN line 12 has two B channels for transmitting user information such as voice and images, and
One D channel for transmitting m information is allocated. Each of the terminal devices 14-1 to 14-8 shares each B channel and D channel on the bus 13.
The l5DN can be accessed through SUI 1.

In such a configuration, a communication procedure when a call is made from one terminal device connected to the bus 13 will be described with reference to FIG.

First, for example, a call setting message 5 is sent from the terminal device 14-1.
When ETUP is sent, this call setup message 5ETU
P is transmitted to ISDN via DSUI 1. l5
When the DN receives the call setup message 5ETUP, it transmits the call setup message 5ETUP to the terminal device on the called side, and also sends a call setup acceptance message containing information specifying which of the two B channels is available. CALLPROC is transmitted to the originating terminal device 14-1. On the other hand, when the terminal device on the called side receives the call setup message 5ETUP, it sends a response message C0NN.
is transmitted to the l5DN. Furthermore, this response message C
0NN is transmitted from the 15DN to the calling side terminal device 14-1.

Such message transmission and reception is performed using the D channel, and after the above message transmission and reception, user information is transmitted and received between the calling side terminal device 14-1 and the receiving side terminal device using the B channel. .

At this time, the terminal device 14-1 on the calling side uses the B channel specified by the call setting acceptance message CALLPROC.

When the transmission of the user information is completed, the following messages are sent and received using the D channel again. First, the terminal device 14-1- on the calling side sends a disconnection message Dis.
c is transmitted to the l5DN.

The l5DN responds to the disconnection message DISC, transmits the disconnection message Dis to the terminal device on the called side, and sends a release message REL to the terminal device 14 on the calling side.
-1. The terminal device on the receiving side responds to the disconnection message Disc and sends a release message REL to l5DN.
to be transmitted. Thereafter, a release completion message RELCOMP is transmitted from the terminal device 14-1 on the calling side to the 15DN, and the same release completion message RELCOMP is transmitted from the 15DN to the terminal device on the receiving side. As a result of the above message transmission and reception, the line between the calling side terminal device 14-1 and the receiving side terminal device is disconnected.

Next, when the terminal device 14-1 on the calling side makes a call, the terminal device on the called side is, for example, in communication, and therefore the called terminal device cannot accept the incoming call, as shown in FIG. Messages like these are sent and received.

That is, the call setup message 5ETUP from the calling terminal device 14-1 is accepted at the I5DN, and the ISD
Even if the call setup message S ETUP is transmitted from N to the called terminal device, the called terminal device does not send a response message C0NN, but instead sends a release completion message R.
Send ELCOMP to l5DN. l5DN sends the call setup reception message CALLPROC to the terminal device 1 on the calling side.
4-1, and then sends the release completion message R.
When E L COMP is received, a disconnection message DIS
C is transmitted to the originating terminal device 14-1.

After this, a release message REL and a release completion message RELCO are sent between the calling side terminal device 14-1 and l5DN.
MP is exchanged, and this causes the originating terminal device 14-1 to
The call ends without any communication taking place between the terminal device on the called side and the terminal device on the called side.

Next, when a call is made from the terminal bag 5f14-1 on the calling side, the other two terminal devices connected to the bus 13
Therefore, if the terminal device 14-1 cannot use the B channels, messages are sent and received as shown in FIG. 8.

That is, even if the calling side terminal device 14-1 sends the call setup message 5ETUP to the l5DN, the l5DN
Since the two B channels assigned to the SDN line 12 are in use, the call setup acceptance message CALL
Instead of PROC, a release completion message RELCOMP is sent to the originating terminal device 14-1. This means that the call setup by the calling side terminal device 14-1 has failed.

Therefore, it can be said that the I5DN side recognizes the usage status of each B channel assigned to the I5DN line.

Here, conventional terminal devices do not know the usage status of each B channel, and therefore may perform call setup even though each B channel is in use, resulting in repeated call setup failures. Ta. In addition, call setup from one terminal device is limited to a predetermined number of times (e.g., 3 times) within a predetermined period of time (e.g., 3 minutes), so call settings cannot be made frequently, and therefore the B channel It is not always possible to set up a call when the station is free. In other words, if there is a vacant B channel and the B channel becomes in use due to a call setup from another terminal device, the terminal must wait until the B channel becomes vacant again.

[Problem to be solved by the invention]

As described above, in conventional terminal devices, call setup may be repeated needlessly even though each B channel is in use, resulting in a problem that the waiting time becomes long.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a terminal device that does not wastefully repeat call setup even when each B channel is in use.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes, in a terminal device connected to a line of a digital integrated service network, a detection means for detecting the usage status of a B channel of the line by monitoring a D channel of the line. and control means for starting a call based on the B channel usage status detected by the detection means when there is a call request.

(Function) According to the present invention, when there is a call request, the call is started based on the detected usage status of the B channel, so it is possible to prevent unnecessary calls from being repeated. can.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a facsimile device to which an embodiment of the terminal device according to the present invention is applied, and this facsimile device is used as a terminal device connected to the bus 13 shown in FIG.

In the figure, a transmission section 1 is an interface connected to a bus 13, and sends and receives signals to and from the bus 13. A scanner section 2 reads a document and sends image information to a transmission section 1 or a memory section 3.

The memory section 3 stores image information from the scanner section 2,
Image information input manually from the bus 13 via the transmission section 1 is stored. The memory control section 4 is for controlling the memory section 3. The printer section 5 records an image on recording paper based on the image information manually inputted from the memory section 3 or the image information manually inputted from the bus 13 via the transmission section 1. Line usage detection section 6
monitors the D channel on bus 13 via transmission section 1;
A message transmitted on the D channel has been detected, and the 6th
The various messages shown in Figures 8 through 8 are detected. When operated, the operation panel 7 manually issues various commands and displays information necessary for operation. The main control section 8 controls this facsimile machine in an integrated manner.

In such a configuration, the operating procedure for transmitting image information will be described with reference to the flowchart in FIG. 2.

First, when a command for call setup is input by operating the operation valve 7, the main control section 8 responds to this command and sends a call setup message 5ETUP to the bus 13 via the transmission section 1 on the D channel. do. This call setup message S ETUP is sent from the / Assume that response messages C0NN are sent back to the facsimile machine sequentially on the D channel.In this case, the line usage detection section 6 in the facsimile machine receives the call setup acceptance message CALLPR from the D channel on the bus 13 through the transmission section 1.
sequentially detecting OC and the response message C0NN;
These messages are notified to the main filJ1mM8.

When the main 14 control unit 8 is notified of the response message C0NN, it determines that it can communicate with the terminal device on the receiving side, and starts controlling the transmission of image information. At this time, l5DN four-wire 12
Since either of the two B channels assigned to the main control unit 8 is specified by the call setup acceptance message CALL, PROC, the main control unit 8 determines that the specified B channel can be used (step 101). Once this determination is made, it is determined which of scanner transmission and memory transmission has been designated by the operation on the operating system panel 7 (step 102). Here, if the original is set in the scanner section 2 in advance and scanner transmission is specified, the main control section 8 starts the scanner section 2 and controls the exit of the image information to the transmission section 1 from the scanner section. 2
(Step 103). In response to this, the scanner section 2 reads the set original and sends image information to the transmission section 1. The transmitter 1 sends this image information to the available channel on the bus 13. This image information is sent from the bus 13 via the DSUI 1 to the 15DN line 12, and further transmitted from the ISDN to the other party's terminal device.

Further, if the image information is stored in the memory section 3 in advance and memory transmission is specified in advance in step 102, the main control section 8 instructs the memory control section 4 to send the image information to the transmission section 1. command (step 104). In response to this,
The memory control section 4 causes the memory section 3 to send image information to the transmission section 1. This image information is sent from the transmission unit 1 to the available channel on the bus 13, and is sent to the DSUII-ISD.
N line 12-ISDN→transmitted to the other party's terminal device.

Such step 103 or step 10
When the transmission of the image information in step 4 is completed, a disconnection message Dis as shown in FIG.
c. The corner broadcast message REL and the release completion message RELCOMP are sent and received, and the B channel that was being used is released.

Next, when making a call from this facsimile device, a call setup message 5ETUP is transmitted from the facsimile device to the l5DN on the D channel, and in response, the l5DN sends a release completion message RELCO as shown in FIG.
When the MP is transmitted to the facsimile machine on the D channel, the line usage detection unit 6 in this facsimile machine
detects the release completion message RELCOMP from the D channel on the bus 13 via the transmission section 1, and notifies the main control section 8 of this message. The main control unit 8 transfers this release completion message RELCOMP to the call setup message 5.
Since it was received immediately after sending ETUP, l5D
It is determined that the two B channels assigned to the N line 11 are both in use (step 101). In this case, if operation panel transmission is specified, the main control section 8 starts up the scanner section 2 and instructs the scanner section 2 to send image information to the memory section 3. In response to this, the original is read by the scanner section 2, and the image information sent from the scanner section 2 is sent to the memory section 3 and stored therein. Also, if memory transmission is specified by operation on the operation panel 7,
The image information previously stored in the memory section 3 is retained as is. Therefore, if it is determined that both B channels cannot be used, the image information is temporarily stored in the memory section 3 (step 105).

Thereafter, the line usage detection unit 6 in this facsimile machine continues to monitor the D channel on the bus 13 via the transmission unit 1 (step 106). Here, since the two B channels are each used by each of the other terminal devices connected to the bus 13, when the communication of one of these terminal devices is terminated, one B channel is used. When released, the release completion message RELCOMP shown in FIGS. 6 to 8 is always sent to the D channel on the bus 13 at this time.

Therefore, the line usage detection unit 6 in this facsimile machine sends a release completion message R from the D channel on the bus 13.
When ELCOMP is detected (step 106), this message is notified to the main control section 8. When the main control unit 8 is notified of this release completion message RELCOMP, l5
It is determined that one of the two B channels assigned to the DN line 12 is free, and the call setup message 5 is sent.
ETUP is sent from the transmission section 1 to the bus 13. It is assumed that this call setting message 5ETUP is transmitted to the 15DN, and in response, the 15DN returns a call setting acceptance message CALLPROC and a response message C0NN shown in FIG. 6, for example. In this case, the line usage detection section 6 in the facsimile machine sequentially detects the call setting acceptance message CALLPROC and the response message C0NN from the D channel on the bus 13 through the transmission section 1, and notifies the main control section 8 of these messages. . When the main control unit 8 is notified of the response message C0NN, it determines that it can communicate with the terminal device on the called side, and starts controlling the transmission of image information. That is, the main control unit 8 determines that the B channel specified by the call setup acceptance message CALLPROC can be used.Step 107
), if this determination is made, the memory section/
The memory control unit 4 controls the exit of the image information once stored in the memory controller 4.
(Step 104). In response to this, the memory control section 4 causes the memory section 3 to send the image information to the transmission section 1. This image information is sent from the transmission unit 1 to the available channel on the bus 13, and is transmitted from the DSUll-ISDN line 12 to the ISDN to the other party's terminal device.

When the image information transmission is finished in this way, a disconnection message DIS shown in FIG.
C1 release message REL and release completion message R
ELCOMP is sent and received, and the B channel that was being used is released.

Further, in step 106, the line usage detection unit 6 detects the
Release completion message RELCOMP while monitoring channel
is detected and one B channel becomes vacant, the facsimile machine transmits a call setup message 5ETUP to the 15DN, and in response, for example, the call setup acceptance message CALLPROC and the disconnection message Disc shown in FIG. is transmitted to the facsimile machine on the D channel, the line usage detection unit 6 transmits the call setup acceptance message CALLPR from the D channel on the bus 13.
sequentially detecting OC and the disconnection message DISC;
These messages are notified to the main control section 8. Upon receiving this disconnection message Disc, the main control section 8 determines that communication is impossible due to the terminal device on the receiving side rejecting the call, and does not start controlling the transmission of image information. After this, a release message REL and a release completion message RELCOM shown in FIG. 7 are sent between this facsimile machine and the 15DN.
P is sent and received.

Here, even though one B channel is vacant, communication is not possible because the receiving side rejects the call, so the number of outgoing calls is a predetermined number of times (for example, 3 minutes).
The facsimile machine continues to make calls, for example, once every minute, so that the number of calls does not exceed three times (for example, three times) (step 107).

That is, if the call setup message 5ETUP is sent again from the facsimile device to the l5DN after one minute, and the communication procedure shown in FIG. The call will be repeated (step 107). If the call setup message 5ETUP is sent from the facsimile device to the l5DN in step 107 and the communication procedure shown in FIG. 6 is performed in response, the memory N5
The image information in 3 is transmitted to the other party's terminal device, and the communication ends. Furthermore, if the call setup message 5ETUP is sent from the facsimile device to the l5DN in step 107, and the communication procedure shown in FIG. It detects the completion message RELCOMP and notifies the main control wholesaler 8 of this message. The main controller 8 transfers this release completion message RELCOMP to the call setup message 5ET.
Since the UP was received immediately after being sent, it is determined that the two B channels assigned to the 15DN line 12 are both in use, and the process returns to step 106. As a result, the line use detection ms6 continues to monitor the D channel on the bus 13 and waits for the release completion message RELCOMP to appear. Then, release completion message RELCO
When MP is detected, one B channel becomes vacant, and the process returns to step 107.

Next, before reaching step 101, upon the first call from this facsimile device, a call setup message SETUP is transmitted from the facsimile device to the ISDN on the D channel, and in response, for example, a Call setting acceptance message CALLPR shown in Figure 7
When the OC and the disconnection message DISC are sequentially returned to the facsimile machine on the D channel, the line usage detection unit 6 in this facsimile machine sends the call setup reception message CALLPROC from the D channel on the bus 13.
and the disconnection message DISC are sequentially detected, and the main control unit 8 is notified of these messages. Upon receiving this disconnection message DISC, the main control section 8 determines that communication is impossible due to the terminal device on the receiving side rejecting the call, and does not start controlling the transmission of image information. At this time, although one vacant B channel is designated by the call setup acceptance message C0NN, the main control unit 8 determines that this B channel cannot be used (step 101).

Then, if the scanner transmission is specified by the operation on the operation panel 7, the main control unit 8 transmits the data to the scanner unit 2.
The image information is sent to the memory unit 3 from the memory unit 3. In response to this, the original is read by the scanner section 2, and the image information sent from the scanner section 2 is sent to the memory section 3 and stored therein. Furthermore, if memory transmission is designated by an operation on the operation panel 7, the image information previously stored in the memory section 3 is retained as is. Therefore, if it is determined that the designated B channel cannot be used, the image information will be temporarily stored in the memory section 3 (
Step 1o5).

Here, one B channel is free, but
Communication is not possible because the receiving party rejects the call.
Jumping to the next step 106, the facsimile machine continues making calls, for example, once every minute (step 1o7). Then, if the call setup message 5ETUP is sent again from the facsimile device to the l5DN one minute later, and the communication procedure shown in FIG. The call will be repeated (step 107). Also, in this step 107, l5 is sent from the facsimile machine.
If the call setup message 5ETUP is sent to the DN and the communication procedure shown in FIG. 6 is performed in response, the image information in the memory section 3 is transmitted to the terminal device of the other party, and communication is started. finish. Furthermore, in step 107, the facsimile machine sends a call setup message 5 to the l5DN.
If ETUP is sent and a communication procedure as shown in FIG. 8 is performed in response, the line usage detection unit 6
The release completion message RELCOMP is detected by
Return to step 106 above. At this time, since both the two B channels are in use, the line usage detection section 6 detects that the bus 1
Release completion message RELCOMP to D channel on 3
Keep watching to see if it appears. When the release completion message RELCOMP is detected, one B channel is vacant, so the process returns to step 107.

Therefore, as shown in the transition diagram of FIG. 3, if the facsimile device requests an empty B channel (Yes in step 201), that is, when two B channels are in use, the line usage detection unit 6 detects that the bus 1 If the release completion message RELCOMP is to be detected from the upper D channel, there is no free B channel (step 2o2).

Here, if the release completion message RELCOMP is detected, there is a free B channel, and by transmitting the call setup message 5ETUP from the facsimile machine to the l5DN, it is possible to supplement the free B channel of the two B channels. It is possible (step 203, step 204). Further, if the facsimile machine does not request a free B channel (No in step 201), there is a free B channel, and the facsimile machine sends the l5DN.
2 by transmitting a call setup message 5ETUP to
A vacant B channel among the two B channels can be supplemented (Step 2o3, Step 204).

By the way, in the above embodiment, since the call setup acceptance message CALLPROC specifying one of the two B channels assigned to the I5DN line 12 is transmitted from the I5DN to the facsimile machine, the B channel to be used is determined on the I SDN side. This means that it is specified by . However, it is also possible to specify which B channel to use out of the two B channels on the facsimile machine side. In this case, the two B channels are channel B1 and channel B2.
For example, as shown in FIG. 4(a), channel B
A call setup message 5ETUP containing information specifying 1 is sent from the facsimile machine to the 15DN. Here, if channel B1 is vacant, a response message C0NN is sent back from 15DN to the facsimile machine, and in response, the facsimile machine transmits image information using channel B1. If channel B1 is not available, the release completion message RELCOMP is returned from the 15DN to the facsimile machine as shown in FIG. 4(b), and in response to this, the facsimile machine waits for the use of channel B1. becomes. In this way, when one of the two B channels is designated on the facsimile machine side, the procedure of the flowchart shown in FIG. 2 is performed in the facsimile machine only for the designated B channel.

As described above, in the facsimile apparatus of this embodiment, when both B channels are in use and image information cannot be transmitted, the image information is temporarily stored in the memory section and the D channel continues to be monitored. When the release completion message RELCOMP appears on the D channel, it determines that the B channel is free and starts making a call.If the other party's terminal device does not reject the call, the image information in the memory is transferred to the B channel. to send it to the other party's terminal device. Therefore, even if each B channel is in use, call setup is not repeated needlessly, and communication can be performed promptly when a B channel becomes available.

In this embodiment, a facsimile machine is exemplified as a terminal device, but the present invention is not limited to this, and the present invention can be applied to any terminal device. Furthermore, it is of course possible to apply the present invention to each terminal device connected to the bus 13 shown in FIG. 5. Furthermore, when a release completion message appears on the D channel, it is determined that the B channel is free. It doesn't matter if you decide.

〔Effect of the invention〕

As explained above, according to the present invention, a call is started based on the detected usage status of the B channel, so there is no need to repeat unnecessary calls, and when the B channel is free Since it is possible to perform communication quickly, it is possible to provide a terminal device that can perform transmission reliably.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a facsimile machine to which an embodiment of the terminal device according to the present invention is applied, FIG. 2 is a flowchart used to explain the operation of the embodiment shown in FIG. 1, and FIG. The figure is a transition diagram showing each state in the embodiment shown in Figure 1, Figure 4 is a diagram illustrating various messages sent and received between the terminal device and the I5DN, and Figure 5 is the transition diagram between the terminal device and the ISDN. The block diagrams illustrating the connection mode and FIGS. 6 to 8 are diagrams illustrating various messages sent and received between the terminal device and the 15DN, respectively. DESCRIPTION OF SYMBOLS 1... Transmission section, 2... Scanner section, 3... Memory section, 4... Memory control section, 5... Printer section, 6.
...Line usage detection unit, 7...Operation panel,
8... Main control unit, 11... Digital line terminal device, 12... 15DN line, 13... Bus, 14-1
~14-8...Terminal device. Figure 3 (C1) Cb) Figure 4 Figure 6 Figure 7 Figure 8

Claims (1)

[Scope of Claims] In a terminal device connected to a line of a digital integrated service network, by monitoring the D channel of the line,
1. A terminal device comprising: a detection means for detecting a channel usage state; and a control means for starting a call based on the B channel usage state detected by the detection means when a call request is received.