JP3000893B2 - Communication method and communication terminal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication method using an ISDN (Integrated Services Digital Network) and a communication terminal device used for implementing the communication method.

[0002]

2. Description of the Related Art One of services using a public telephone line network.
Toll-free service that charges the callee to the callee
(Registered trademark) (the same applies hereinafter) service. Since this charging process is performed under the control of the network service control station on the public telephone line network, a business operator or the like who intends to use the toll-free service submits a notification for receiving the service, and obtains a contract number in advance. You need to get it. However, such a procedure is troublesome when the free dial service is used continuously, but when it is used only for a short period of time. Therefore, there are various types of technologies that do not use the toll-free service provided by the public telephone network, but call back from the called communication terminal device to the calling communication terminal device to substantially charge the incoming call. It has been proposed. An example is shown below.

<First Prior Art> Once a call connection is made between a calling communication terminal and a called communication terminal, information for making a call back to the calling communication terminal is transmitted to the called communication terminal. The terminal device is notified, and then, the called-side communication terminal device calls back the calling-side communication terminal device.

[0004] <Second Prior Art> [0004] A communication terminal device receiving an incoming call from an ISDN stores the calling party number of the incoming call in a storage means, notifies the ISDN of the end of the call, and then stores it in the storage means Make a call to the stored calling number. This technique is disclosed in JP-A-5-14548 (title of the invention: toll-free terminal device).

[0005]

In the first prior art, it takes a long time to exchange information for callback, and the call connection is not performed once for exchanging the information. This has the disadvantage of charging the caller. In addition, there is a problem in security because of the method of performing call connection.

In the above-mentioned second prior art, the receiving side terminal device notifies the end of the call without responding to the call connection.
There is no charge to the caller for unnecessary calls. However, due to the characteristics of ISDN, the communication terminal on the calling side considers the possibility of connection to another communication terminal on the same bus as the communication terminal on the receiving side, and takes a call after receiving a notification of the end of call. There is a problem that it is necessary to wait for about 4 seconds until the backing is performed, and the time required for finally making a call becomes longer.

[0007] The present invention has been made in view of the circumstances described above, and it is possible for a called party to carry out communication while paying a communication charge only by processing on the communication terminal device side. It is an object of the present invention to provide a communication method and a communication terminal device in which the time required for a call connection procedure can be reduced.

[0008]

The invention according to claim 1 is
An originating communication terminal device transmitting a first call setup message identifying a called communication terminal device to a network, the receiving communication terminal device receiving the first call setup message from the network, and calling back; If it is ready to accept the request, it sends a call message to the network and starts timing, the originating communication terminal device sends a disconnection message by receiving the call message from the network, If the communication terminal device receives the disconnection message from the network before the end of the predetermined period of time, the communication terminal device determines that the calling communication terminal device has requested a callback,
Disconnecting the call, transmitting a second call setup message identifying the originating communication terminal device to the network,
The gist of the communication method is that the originating communication terminal device makes a call connection in response to the second call setup message. Also, in the invention according to claim 2, in the configuration according to claim 1, the receiving-side communication terminal device, when receiving the disconnection message from the network after a predetermined period of time has been measured, the transmitting-side communication terminal device A gist of the present invention is a communication method characterized in that it is determined that there is an abnormality in a procedure of a callback request by a communication terminal device, and the callback request is rejected. Further, the invention according to claim 3 is based on claim 1.
Or in the configuration according to 2, wherein the receiving communication terminal device, if not ready to accept a callback request, sends a response message to the network in response to the first call setup message from the calling communication terminal device. Transmitting, when the calling communication terminal device requests a callback to the called communication terminal device, disconnects the call in response to the response message received from the network. The method is the gist.

[0009] The invention according to claim 4 is the invention according to claim 1.
3. The configuration according to claim 1, wherein
The called communication terminal accepts the callback request
If not, the second communication from the originating communication terminal is performed.
Response message to the call setup message
And the originating communication terminal device transmits the
When the calling side does not request the calling side communication terminal
The response message received from the network if
A call connection with the called communication terminal device in response to the
The gist is a communication method characterized by the following.

The invention according to claim 5 relates to a receiving-side communication terminal device in the communication method according to claim 1, wherein the receiving-side communication terminal device receives a first call setup message from a network, and receives the first call setting message from the calling-side communication terminal device. If it is ready to accept the callback request, it sends a call message to the network and starts timing, and if it receives a disconnect message from the network before the end of the predetermined period of time, Communication means comprising: means for determining that the terminal device has requested a callback, disconnecting the call, and transmitting a second call setup message specifying the originating communication terminal device to the network. The terminal device is the gist.

[0011]

According to the first to fifth aspects of the present invention, the call connection is finally performed in response to the call setting message issued by the communication terminal device on the receiving side. Can communicate. Further, after the originating communication terminal device issues a call setup message, the originating communication terminal device issues a disconnection message, so that the terminating communication terminal device can immediately issue the call setup message. And the time required for the procedure for call connection is reduced.

[0012]

EXAMPLES In order to make the present invention easier to understand,
An example will be described. These examples show one embodiment of the present invention, and do not limit the present invention, and can be arbitrarily changed within the scope of the present invention.

FIG. 1 is a block diagram showing a configuration of a communication terminal device according to one embodiment of the present invention. This communication terminal device is a device that communicates with another communication terminal device via ISDN, and includes a CPU 1 that controls the operation of the entire device as shown in FIG. This CPU 1
It is connected to the ISDN via the DN interface 2, and according to a predetermined communication protocol,
Control of each unit for performing communication using N is performed. The operation of the embodiment described later is performed under the control of the CPU 1. This communication terminal device includes a memory 3 as storage means for various control information, a power supply 4, an LED 5 for displaying a call state, and a LAN provided in the premises.
(Local area network).

FIG. 2 is an operation sequence diagram showing the most characteristic communication procedure of this embodiment performed by the communication terminal device described above. In this figure, both communication terminal devices A and B are the communication terminal devices shown in FIG. The figure shows the operation when the communication terminal device A makes a callback request and the communication terminal device B accepts this request. FIG. 3 is a flowchart showing the operation of the communication terminal device A as the transmitting side, and FIG. 4 is a flowchart showing the operation of the communication terminal device B as the receiving side. Most of the processes shown in these flowcharts are shown in the operation sequence of FIG. In FIG. 3 and FIG. 4, a box (step code Sxxx) for convenience of description is attached to a box representing each process.
Also in the operation sequence diagram of FIG. 2, common reference numerals are used to clarify which of the steps in FIGS. 3 and 4 corresponds to each process illustrated in FIG. 2. Hereinafter, the operation of this embodiment will be described with reference to these drawings.

First, the communication terminal device A, which is the calling side, sets up a call setting message Setu including a calling number (telephone number of the communication terminal device A) and a called number (telephone number of the communication terminal device B).
p is sent to the ISDN, and a request for call setup with the communication terminal device B is made (step S101). The ISDN sends a call setup message Setup to the designated communication terminal device B to make a call.

When the communication terminal device B on the receiving side detects an incoming call (step S201), the call setting message Se.
The calling number (telephone number of the communication terminal device A) is extracted from the tup and written in the memory 3. Next, when the operation mode for accepting the callback request is set, the communication terminal device B sends a call message Alert to the ISDN.
Are continuously transmitted at predetermined intervals (steps S202 and S202).
203). Further, the communication terminal device B transmits the call message A
Simultaneously with the transmission of lert, the internal timer starts measuring a predetermined time. ISDN is the call message Ale
By transmitting rt to the communication terminal device A, it is notified that the call of the communication terminal device B has started.

The communication terminal device A on the transmitting side detects that the communication terminal device B is ready to accept the callback by detecting the reception of the call message Alert, and immediately sends a disconnection message Disc to the ISDN. (Steps S102 and S103). And I
The SDN transmits the disconnection message Disc to the communication terminal device B.
To send to.

As described above, the communication terminal device B as the receiving side is:
After the call message Alert is sent to the communication terminal device A, the disconnection message Disc will be received before the timing of the predetermined time by the timer ends (timeout) (step S204). As a result, the communication terminal device B recognizes that the communication terminal device A is requesting the callback. Then, the communication terminal device B sends out a release message Rel, and in response to this, the communication terminal device A
Sends a release completion message Rel Comp (steps S205 and S104). As described above, since the information channel (B channel) is not set by calling the communication terminal device A on the calling side, the communication terminal device A is not charged.

Thereafter, the communication terminal device B, which is the receiving side,
The calling number stored in the memory 3, that is, the telephone number of the communication terminal device A is read out, and the call setting message Setup using the telephone number of the communication terminal device A as the destination number is sent to the ISD.
N, and requests for a call setup with the communication terminal A (step S206). In this case, the communication terminal device A on the calling side
Has already issued the disconnection message, the communication terminal device B on the receiving side can immediately issue the call setup message without waiting time, and the time required for the procedure for call connection can be reduced. The ISDN sends a call setup message Setup to the designated communication terminal device A to make a call (step S105). Then, the communication terminal A receives the call setting request, and the normal connection procedure is performed by the communication terminal A.
(Steps S106 and S20)
7). Then, an information channel (B channel) is set by calling the communication terminal device B, and after the communication is completed, the communication terminal device B is charged.

The above is the operation when the communication terminal device B accepts the callback request from the communication terminal device A.

As described above, when the communication terminal device A requests a callback to the communication terminal device B, it is necessary to immediately transmit a disconnection message Disc to the ISDN after detecting the call message Alert. There is. If the disconnection message Disc is not immediately transmitted, the communication terminal B transmits the disconnection message Disc.
Before receiving c, the counting by the timer ends (step S204). In this case, the communication terminal device B
Transmits a disconnection message Disc (step S2).
21). Then, a release message Rel transmitted from the communication terminal device A in response to the disconnection message Disc
Is transmitted, and in response to this, a release completion message Rel Comp is transmitted to the communication terminal device A (step S22).
2). When the procedure of the callback request performed by the communication terminal device A is abnormal as described above, the request is rejected. Also in this case, since the information channel (B channel) is not set by the calling of the communication terminal device A on the calling side, the communication terminal device A is not charged.

Next, the operation when the communication terminal device B is not ready to accept the callback request will be described with reference to FIGS.

In this case, the call setup message Setup from the communication terminal A is transmitted to the communication terminal B via the ISDN.
(Step S201), the communication terminal device B transmits a response message Conn to the communication terminal device A via the ISDN (step S211). When the communication terminal device A accepts the response message Conn, communication is started between the communication terminal devices A and B (step S212). Such an operation is performed when the communication terminal A makes a normal call to the communication terminal B instead of a callback request.

There is a case where the communication terminal A makes a callback request but the communication terminal B is not ready to accept the request. In this case, a response message Conn is sent from the communication terminal device B to the call setup message Setup from the communication terminal device A, and the communication terminal device A receives the response message Conn, and the communication terminal device B issues a callback request. It is detected that it is not ready to accept (step S102). As a result, the communication terminal device A sends a disconnection message Disc (step S
111), and then transmits a release message Rel, and receives a release completion message Rel Comp transmitted by the communication terminal device A in response to this (step S112).
Also in this case, since the information channel (B channel) is not set by the calling of the communication terminal device A on the calling side, the communication terminal device A is not charged.

In the above-described embodiment, the calling communication terminal device transmits the disconnection message Dis within a predetermined time after the called communication terminal device sends the calling message Alert.
Whether or not a normal callback request has been made is determined based on whether or not c is transmitted. However, the method of determination is not limited to this. For example, in the case of making a callback request, the calling communication terminal device transmits a call setting message Setup including information indicating the fact, and the called communication terminal device determines whether or not such information exists. The presence or absence of a back request may be determined.

The communication terminal device has not only a function as the transmitting side communication terminal device and a function as the receiving side communication terminal device but also a communication terminal device functioning as only one of them. Is also good.

[0027]

As described above, according to the present invention, it is possible for the called party to carry out the communication while paying the communication charge only by the processing on the communication terminal side, and to perform the call connection in that case. This has the effect of reducing the time required for the procedure for

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a communication terminal device according to an embodiment of the present invention.

FIG. 2 is an operation sequence diagram showing an operation of the embodiment.

FIG. 3 is a flowchart showing the operation of the embodiment.

FIG. 4 is a flowchart showing the operation of the embodiment.

[Explanation of symbols]

A: originating communication terminal device; B: destination communication terminal device.

Claims (5)

(57) [Claims] 1. An originating communication terminal device sends a first call setup message specifying a called communication terminal device to a network, and the called communication terminal device sends the first call setting message from the network to the first communication terminal device.
Receiving the call setup message and accepting the callback request, transmits the call message to the network and starts timing, and the originating communication terminal device receives the call message from the network. When the receiving communication terminal device receives the disconnect message from the network before the end of the predetermined period of time, the calling communication terminal device requests a callback. Determining, disconnecting the call and transmitting a second call setup message identifying the calling communication terminal device to the network, wherein the calling communication terminal device responds to the second call setup message to make a call. A communication method comprising establishing a connection. 2. The reception-side communication terminal device, when receiving the disconnection message from the network after a predetermined period of time has ended, determines that there is an abnormality in the callback request procedure by the transmission-side communication terminal device. 2. The communication method according to claim 1, wherein the determination is made and the callback request is rejected. 3. The receiving communication terminal device, if not ready to accept a callback request, sends a response message to the network in response to a first call setup message from the calling communication terminal device, 2. The communication device according to claim 1, wherein the calling communication terminal device disconnects the call in response to the response message received from a network when requesting a callback to the called communication terminal device. 3. The communication method according to 2. 4. The receiving communication terminal device, if not ready to accept a callback request, transmits a response message to the network in response to a first call setup message from the calling communication terminal device, If the calling communication terminal device does not request a callback to the called communication terminal device, the calling communication terminal device establishes a call connection with the called communication terminal device in response to the response message received from the network. The communication method according to any one of claims 1 to 3, wherein the communication method is performed. 5. When the first call setup message is received from the network and the system is ready to accept the callback request from the calling communication terminal device, the call message is transmitted to the network and time counting is started. If a disconnection message is received from the network before the time period ends, the originating communication terminal determines that it is requesting a callback, disconnects the call, and disconnects the originating communication terminal. A communication terminal device comprising means for transmitting the specified second call setup message to a network.