JP3058584B2 - Wide area button telephone system and ISDN telephone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of ISs connected to an ISDN network and distributed at a plurality of points.
The present invention relates to a key telephone system including a DN telephone (hereinafter referred to as a wide area key telephone system) and an ISDN telephone used in the system.

[0002]

2. Description of the Related Art In a general key telephone system, a main unit is connected to a telephone network, and a plurality of key telephones as a plurality of extension telephones are connected to the main unit. Line connection with a key telephone,
Calls between extension telephones (extension calls) are controlled.

In the key telephone system, when an incoming call through the telephone network is received by any telephone in the system,
Answer can be made on any telephone in the system.
However, the conventional key telephone system can realize its function within the range of a plurality of key telephones that can be connected to the main unit with a cable. I couldn't get it.

[0004] A transfer function is a method for linking between persons at such remote locations. For example, telephones having this type of transfer function, such as the transfer function of an answering machine, are also widely used.

For example, in the transfer function of an answering machine, the telephone number of one specific transfer destination is registered in the answering machine in advance. When there is an incoming call to the answering machine, the answering machine temporarily answers the call and re-calls the telephone having the preset telephone number. The transfer function is realized by linking the calls.

In the case of an ISDN network, the above-described call transfer function can be realized without making a temporary response by using the call transfer service of the ISDN network. Also in this case, the user sets a telephone number of a specific transfer destination in the ISDN telephone in advance. When the ISDN telephone receives an incoming call from the network via the D channel, when no one responds to the incoming call for a certain period of time, or when the telephone is in use, the above-mentioned presetting is performed. Redial (transfer request) to the telephone with the same telephone number. Then, ISDN
The network transfers the incoming call to the transfer destination telephone number based on the transfer request.

[0007] Thus, even at a distance, the two telephones connected via the telephone network can be
Call forwarding can be performed.

[0008]

By the way, when an incoming call is received at one of a plurality of telephones distributed at a plurality of points distant from each other via a telephone network, the incoming call is transmitted to the plurality of telephones. If any one of the telephones can answer the call, it is very convenient to construct a wide area button telephone system equivalent to constructing one key telephone system with these plural telephones.

In order to realize such a wide-area key telephone system, the above-mentioned answering machine transfer function and ISDN
It is conceivable to use the transfer service of the network.

However, in the case of the above-described answering machine transfer function and the transfer service of the ISDN network, only one telephone set can receive the transfer at a time. For this reason, even if the above-described transfer function or transfer service is used, when an incoming call is received at any one of a plurality of telephones distributed at three or more locations via the telephone network. However, it is not possible to realize a function in which any one of the plurality of telephones can respond to the incoming call.

It is an object of the present invention to realize the above-mentioned wide area telephone system and to provide an ISDN telephone constituting the wide area telephone system.

[0012]

A wide area key telephone system according to the present invention comprises a plurality of ISDN telephones installed at multiple points via an ISDN network.
Each of the ISDN telephones includes a calling unit, an operation unit that receives a button input operation by a user, and a storage unit that stores a telephone number of at least one of the plurality of ISDN telephones other than its own telephone. A control unit having a function of transmitting a control command for receiving a D-channel packet switching service of the ISDN network and a function of receiving and decoding the control command;
A display unit for displaying an incoming state of the N telephone, and each control unit of the ISDN telephone uses the telephone number of the storage unit when receiving an incoming call to the line of the own telephone. Outgoing call information indicating that there is an incoming call on the line of the own telephone as a D channel packet of the ISDN network,
When a D-channel packet containing the incoming information is received, the incoming state of the ISDN telephone that transmitted the incoming information is displayed on the display unit, and the incoming state to another ISDN telephone is displayed on the display unit. When the user performs a transfer request operation through the key input operation unit, the information of the transfer request is transmitted to the incoming IS
When the D-channel packet is transmitted to the DN telephone and the D-channel packet including the transfer request information is received, the incoming call is transmitted to the ISDN telephone that transmitted the transfer request by an incoming transfer service of an ISDN network. A message requesting that the IS
It is characterized in that it is transmitted to a DN network.

[0013]

In the present invention having the above configuration, a plurality of ISDN telephones connected to an ISDN network are grouped. The grouping is performed by storing the telephone numbers of all other ISDN telephones in the group in the respective storage units of the ISDN telephones. When a call arrives at a certain ISDN telephone A in the group, the telephone A transmits to all other ISDN telephones a D-channel packet indicating that the telephone A has arrived. Is done.

The other ISDN telephone which has received the D-channel packet including the information on the incoming call to telephone A displays on the display unit that telephone A is in a receiving state. Thus, all the ISDN telephones in the group notify their users that there is an incoming call to the ISDN telephones A in the group.

[0015] When a response operation is performed on any other ISDN telephone in the group while the other ISDN telephone indicates that it is in a receiving state, the incoming call is received by the arbitrary other ISDN telephone. be able to.

That is, if one ISDN telephone B is
When responding to the incoming call to the SDN telephone A, the control unit of the telephone B transmits the information of the transfer request to the incoming I
The packet is transmitted to SDN telephone A as a D channel packet.

Upon receiving this D-channel packet, ISDN telephone A sends a call transfer request message including the telephone number of ISDN telephone B as a transfer destination to the ISDN network.

In response to the call transfer request message, the ISDN network changes the incoming call to ISDN telephone A to IDN
Transfer to SDN telephone B. Therefore, an incoming call to any one of the ISDN telephones A in the group can be answered by any other ISDN telephone B in the same group as this telephone A, and the incoming call can be transmitted via the ISDN network. ISDN grouped at remote locations
It is possible to realize a wide area button telephone system in which a telephone functions as one key telephone system.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the wide area key telephone system according to the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 2 shows a general outline of a wide area key telephone system according to the first embodiment. The wide area key telephone system according to the first embodiment comprises: A plurality of, in this example, three ISDN telephones 1, 2, 3 constituting one group are connected to a line L, respectively.
It is configured to be connected to the ISDN network 4 via L1, L2 and L3.

The grouping of the three ISDN telephones 1, 2, and 3 is performed by each of the telephones 1, 2, and 3 storing the telephone numbers of the other telephones in the group in the storage unit. The storage of the telephone number is performed, for example, by a user or a telephone contractor. In FIG. 2, a telephone 0 connected to the ISDN 4 indicates an ISDN telephone outside the group. However, the storage unit may store the telephone numbers of all the ISDN telephones to be grouped, including the telephone numbers of the own telephones.

In this embodiment, as described later, it is possible to respond to an incoming call to a line to which all ISDN telephones in a group constituting the wide area key telephone system are connected. That is, the wide area button telephone system of this embodiment operates as if one telephone is connected to a plurality of lines in the group.

Each of the ISDN telephones 1 to 3 has the same configuration, and FIG. 3 shows an external view thereof, and FIG. 4 shows a circuit configuration thereof.

As shown in FIG. 3, the IS of this embodiment
The DN telephone includes a transmitter / receiver 11, a telephone main body 12, and a connection cord 13 for connecting between the transmitter / receiver 11 and the telephone main body 12. The telephone body 12 is provided with a dial button 21 composed of a number button, a “*” button, and a “#” button, a line selection button group 22, and a line status display group 23.

Each line selection button of the line selection button group 22 can be used for capturing the line of the own telephone (hereinafter referred to as own line) and the line of another telephone in the group (hereinafter referred to as other line). The line selection buttons to be set are provided corresponding to the maximum number of ISDN telephones to be grouped. In this embodiment, 1
One line is allocated to one ISDN telephone, but IN
In the case of 2B + D of S net 64, B channel is 2
Considering that channels can be used, two line selection buttons are set for capturing per line.

In this embodiment, up to three ISDN telephones can be grouped. Therefore, the line selection button group 22 includes the line selection button buttons 22a and 22a.
b, 22c, 22d, 22e, and 22f are provided, and one pair of buttons is allocated to the own line, and the other two pairs of buttons are allocated to lines of other telephones in the group. Assigned to.

For example, in the case of the ISDN telephone 1, the setting of the line selection buttons 22a to 22f is performed as follows.

Line selection button 22a: B0 of own line L1
Channel selection line selection button 22b: Channel B1 channel of own line L1 Line selection button 22c: Response of incoming call to B0 channel of other line L2 Line selection button 22d: Call reception of B1 channel of other line L2 Response line selection button 22e: For response to incoming call to B0 channel of other line L3 Line selection button 22f: For response of incoming call to B1 channel of other line L3.

The line status display group 23 is composed of line status indicators corresponding to the respective line selection buttons of the line selection button group 22. In the case of this embodiment,
Six line status indicators 23a to 23f are provided corresponding to the six line selection buttons 23a to 23f, respectively, and the lines to which the respective line selection buttons 22a to 22f are assigned are being received, being used, Display the line status such as transferring.

Each of the line status indicators 23a to 23f has a built-in red lamp and a green lamp for displaying the line status. The lighting and blinking states of these lamps indicate the following line states.

Red lamp lit: other phone in use Red lamp flashing: Incoming call on other line Green lamp lit: own phone in use Green lamp flashing: Transferring

For example, each of the line status indicators 23a to 23f of the ISDN telephone 1 is set as follows in the case of this embodiment, similarly to the line selection buttons 22a to 22f.

Line status indicator 23a: B0 of own line L1
Channel status display Line status display 23b: B1 channel status display of own line L1 Line status display 23c: B0 channel status display of other telephone 2 Line status display 23d: B1 channel status display of other telephone 2 Line Status display 23e: Status display of B0 channel of other telephone 3 Line status display 23f: Status display of B1 channel of other telephone 3

The line status indicators 23a to 23f
When the line selection buttons 22a to 22f are set, the control unit of the ISDN telephone, which will be described later, automatically sets the state of the line of the adjacent line selection button in each line status indicator. Is what you do.

Next, the IS of this embodiment shown in FIG.
The circuit configuration of the DN telephone will be described. That is, as shown in FIG. 4, the ISDN telephone of this embodiment
The control unit 100 includes a microcomputer, and includes a line interface unit 31, a communication unit 32, an operation unit 33, a display unit 34, and a storage unit 35 in which various controls are performed by the control unit 100.

The line interface unit 31 is connected to the ISDN line L, and is connected to the ISDN line L
Control the transfer of data between 0 and ISDN
The transmission / reception of a call voice signal between the line L and the call unit 32 is controlled.

The communication unit 32 includes the handset 11, emits a reception voice from the speaker of the handset 11, and transmits the transmission voice collected by the microphone of the handset 11 to the line interface unit 31. To the ISDN line L via

The operation unit 33 includes a hook switch corresponding to on-hook and off-hook by raising and lowering the handset 11,
The control unit 100 includes a dial button 21 and a line selection button group 22, receives a button operation input by a user, and outputs a button operation signal corresponding to the button operation input.
To supply.

The control unit 100 determines which button has been operated from the button operation signal, and performs control according to the button operation. Although not shown in FIG. 3 for simplicity of description and because it has nothing to do with the present invention, the operation unit 33 includes a button for abbreviated dial and an operation button for a one-touch dial. There is also.

The display unit 34 includes the line status display group 23. The display control signal from the control unit 100 turns on and off the red and green lamps of the line status indicators 23a to 23f. Controlled.

The storage unit 35 stores the telephone numbers of at least other ISDN telephones in the group described above. In the case of this embodiment, three ISDN telephones 1, 2,.
The telephone numbers of the telephone numbers other than the telephone number are stored. The storage unit 35 also stores telephone numbers such as speed dials and one-touch dials.

As described above, the telephone numbers of the other ISDN telephones to be grouped are set by the operator of the telephone installation work or the user himself / herself so as to constitute the wide area telephone system, and are stored in the storage unit 35. It is memorized.

According to the present invention, a wide area key telephone system is realized by using a D channel packet switching service. In order to configure the wide area key telephone system, the control unit 100 of each ISDN telephone requires a D channel packet telephone system. Transmission and reception functions.

FIG. 5 is a functional block diagram in which, among the processing functions of the control unit 100, in particular, those processing function parts for realizing the main parts of the present invention are extracted and shown.

That is, the control unit 100 includes a packet switching processing unit 101, a circuit switching message processing unit 102,
An operation input decoding unit 103 and a call control processing unit 104 are provided.

The packet switching processing unit 101 receives control information from the call control processing unit 104 and receives
The incoming call information and transfer request to be transmitted to the SDN telephone are generated as a D channel packet and transmitted to the destination (one or all of the other ISDN telephones in the group) indicated by the control information.

The packet switching processing unit 101 also receives a D channel packet from another telephone via the line interface unit 31 and supplies it to the call control processing unit 104. Then, the packet switching processing unit 101 transmits another ISD
The status information of the N telephones is sent to the call control processing unit 104.

The circuit switching message processing unit 102 transmits and receives a line effect message such as an outgoing call, an incoming call, a response, and a transfer request to and from the ISDN network based on a control signal from the call control processing unit 104. Then, the circuit switching message processing unit 102 determines the line state of the own telephone (the state of the own line).
Is supplied to the call control processing unit 104.

The operation input decoding unit 103 includes an operation unit 33
, And determines which button has been pressed, and supplies the determination result to the call control processing unit 104.

The call control processing unit 104 receives the information on the state of the other telephone from the packet switching processing unit 101, the information on the own line state from the circuit switching message processing unit 102, and the discrimination result from the operation input decoding unit 103. , Display unit 3
4 supplies a display control signal for controlling the lighting and blinking of the display lamps of the line status indicators 23a to 23f to the display unit 34, and, if necessary, the telephone of another ISDN telephone stored in the storage unit 35. The number is read out, and a control signal for transmitting necessary information to the destination of the telephone number by a D channel packet is transmitted to the packet switching processing unit 101.

In the first embodiment having the above hardware configuration, one ISD in a group
A function of a main part of the present invention, which enables a response from another ISDN telephone in the group when the N telephone receives a call, is shown in the sequence diagram of FIG. 7 will be described below with reference to a line state transition diagram of FIG.

<Transmission> First, a sequence at the time of transmission from the ISDN telephone according to this embodiment will be described with reference to the line state transition diagrams of FIG. 6 and FIG.

FIG. 6 shows one ISDN of this embodiment.
FIG. 7 is a state transition diagram of the own line of the telephone, and FIG. 7 is a state transition diagram of another line. In FIG. 6, when the own line is not used and is in the idle state S1, the line status indicator of the corresponding own line has both the red lamp and the green lamp turned off.

In the idle state S1, when an off-hook operation is performed, the own-line selection button is pressed, a dial button operation is performed, and a calling operation is performed.
The call control processing unit 104 of the control unit 100 controls the circuit switching message processing unit 102 to
1 is transmitted to the ISDN network through the ISDN network 1, the telephone numbers of all the other ISDN telephones constituting the group are called from the storage unit 35, the packet switching processing unit 101 is controlled, and all the other ISDN telephones are controlled. , The line use information is transmitted by the D channel packet DP1. Then, the call control processing unit 104 changes the state of the own line from the idle state S1 to the calling state S2, controls the display unit 34, sets the line state indicator of the own line to a green lamp lighting state, and Displays that the line is in use.

At this time, in another ISDN telephone, the D-channel packet D
Upon receiving P1, the call control processing unit 104 determines the information of the received packet as the line use information. The call control processor 104 of the other ISDN telephone receives the determination result of the line use information and shifts the line state from the other line idle state S11 to the other line use state S12 as shown in FIG. , The corresponding other line status indicator on the display unit 34 is turned on by the red lamp.

When the user stops on-hook operation by on-hook operation because the other party does not respond to the outgoing call, the call control processing unit 104 of the ISDN telephone sets
By recognizing this from the determination result from the operation input decoding unit 103, calling the telephone numbers of all the other ISDN telephones constituting the group from the storage unit 35, and controlling the packet switching processing unit 101, As shown in 6,
D channel packet DP2 allows all other IS
It sends outgoing call abandonment information to the DN telephone.

Then, the call control processing unit 104 returns the state of the own line to the idle state S1, controls the display unit 34, and turns off both the red lamp and the green lamp of the corresponding line state indicator of the own line. Return to the state.

On the other hand, in another ISDN telephone, the packet switching processing section 102 receives the D-channel packet DP2, and the call control processing section 104 determines the information of the received packet as the information abandoned during transmission. And this other ISD
The call control processing unit 104 of the N telephone returns the line state from the other line busy state S12 to the other line idle state S11 based on the discrimination result of the outgoing call abandonment information as shown in FIG. The corresponding other line status indicator of the unit 34 returns the red lamp and the green lamp to an extinguished state.

In the own-line calling state S2 of FIG. 6, when the other party answers the call, the response information is transmitted to the call control processing unit 104 via the circuit switching message processing unit 102.
Therefore, the call control processing unit 104 shifts the state of the own line to the state S3 during the own line communication, controls the display unit 34, and turns on the green lamp of the corresponding line state indicator of the own line. Let At this time, the control unit 100 controls the line interface unit 31 and the communication unit 32 to form a communication link. The other ISDN telephone keeps the state S12 in which another line is being used.

When the on-hook operation is performed on the ISDN telephone that has made the call, the call control processor 104
Recognizes the fact from the determination result from the operation decoding unit 103, calls the telephone numbers of all the other ISDN telephones forming the group from the storage unit 35, controls the packet switching processing unit 101, As shown in FIG.
D channel packet DP3 allows all other IS
Call termination display information is transmitted to the DN telephone.

Then, the ISDN telephone that has made the call returns the state of its own line to the idle state S1.
The display unit 34 is controlled to return both the red lamp and the green lamp of the corresponding line status indicator of the own line to the extinguished state.

On the other hand, in another ISDN telephone, the packet switching processing unit 101 receives the D channel packet DP2, and the call control processing unit 104 determines the information of the received packet as the end display information. Then, the call control processing unit 104 of the other ISDN telephone receives the discrimination result from the end-of-call display information and changes the line state from the other line in use state S12 to the other line idle state S11 as shown in FIG. Back to
The corresponding other line status indicator on the display unit 34 is returned to the off state of the red lamp and the green lamp.

<Incoming Call> Next, the sequence at the time of incoming call in the first embodiment will be described with reference to the state transition diagrams of FIG. 6 and FIG. In the following description, among a plurality of ISDN telephones in a group, an ISDN telephone that has received an incoming call on its own line is referred to as telephone R, and another ISDN telephone that issues a transfer request for the incoming call is referred to as telephone T. .

When the own line is in the idle state S1, IS
When there is an incoming call to the DN telephone R, an incoming message is sent from the ISDN network 4 via the D channel. Therefore, in the control unit 100 of the telephone R, this is received by the circuit switching message processing unit 102, and the call control processing unit 104
Calls the telephone numbers of all the other ISDN telephones forming the group from the storage unit 35, controls the packet switching processing unit 101, and transmits the D channel packet DP4 to all of the other ISDN telephones by the D channel packet DP4. Sends incoming display information.

Further, the call control processing unit 104 of the ISDN telephone set R which has received the incoming call has a line status indicator of its own line on the display unit 34 (for the sake of simplicity, B0 channel, B1 channel for each telephone line). The display control signal is sent to the user, the red lamp is flashed, the speaker is sounded, and the user is informed that the telephone R is receiving a call, that is, the terminal is receiving a call. Inform.

On the other hand, in another ISDN telephone which has received the D channel packet D4, the call control processing section 104 determines the information of the received packet as the incoming call display information. Then, the call control processing unit 104 of the other ISDN telephone sets
Based on the discrimination result with the incoming call display information, as shown in FIG. 7, the state of the corresponding other line is changed from the idle state S11 to the state of receiving another line S13, and the corresponding other line is displayed on the display unit 34. The line status indicator is turned on and off with the red lamp blinking, and the speaker is sounded to notify the user that there is an incoming call to another line whose red lamp is blinking.

In response to an incoming call of the ISDN telephone R to its own line, the line selection button of the operation unit 33 of the ISDN telephone R whose corresponding line status indicator is blinking red is operated, and the handset 11 When an off-hook operation is performed, the operation input is discriminated by the operation input decoding unit 103, and upon receiving the discrimination output, the call control processing unit 104 determines that there is an incoming call response, and the line interface unit 31 and the communication unit 32 , Generate a call link, and put the call into a call state.

Then, the call control processor 104 of the telephone set R
Calls the telephone numbers of all the other ISDN telephones constituting the group from the storage unit 35, controls the packet switching processing unit 101, and, as shown in FIG. The busy display information is transmitted to the ISDN telephone. Then, the line state of the own line is shifted to the state S3 during the own line communication, and the display unit 34 is controlled so that the line state indicator of the own line that has received the incoming call is turned on by the green lamp.

On the other hand, in another ISDN telephone that has received the D channel packet D5, the call control processing unit 104 determines that the information of the received packet D5 is busy display information.
Then, the call control processing unit 104 of the other ISDN telephone set
Shifts the state of the corresponding other line from the state of receiving another line S13 to the state of using other line S12 based on the determination result of the busy display information, as shown in FIG. The line status indicator of the other line corresponding to the line receiving the incoming call of the ISDN telephone R is turned on by a red lamp.

When the user performs an on-hook operation on the ISDN telephone set R that has received the incoming call, the call control processing unit 104 recognizes the fact from the determination result from the operation input decoding unit 103 and recognizes the fact. Calls the telephone numbers of all the other ISDN telephones forming the group, and controls the packet switching processing unit 101 to transmit the D-channel packet DP3 to all the other ISDN telephones as shown in FIG. To send the call end display information.

Then, the state of the own telephone set R is returned to the idle state S1, and the display unit 34 is controlled to turn off both the red lamp and the green lamp of the corresponding line state indicator of the own line. return.

On the other hand, in another ISDN telephone, the packet switching processing unit 101 receives the D channel packet DP2, and the call control processing unit 104 determines that the information of the received packet is the end display information. Then, based on the discrimination result with the end-of-call display information, the call control processing unit 104 of the other ISDN telephone sets the state of the other line (the line receiving the incoming call of the telephone R) as shown in FIG. Line in use state S12
To the other line idle state S11, and
The line status indicator of the other line corresponding to the line of the ISDN telephone R is returned to the state where the red lamp and the green lamp are turned off.

Further, when the incoming call is abandoned without responding to the incoming call at the ISDN telephone set R, that is, when the other party interrupts the call, the process is as follows.

In the ISDN telephone set R, if the control unit 100 determines in the state S4 that the own line is receiving an incoming call, for example, the call control processing unit 104 through the circuit switching message processing unit 102 determines that the incoming call should be abandoned due to the interruption of the call originating from the other party. The processing unit 104 calls the telephone numbers of all the other ISDN telephones constituting the group from the storage unit 35, controls the packet switching processing unit 101, and
D channel packet DP for all N phones
6 sends out the incoming call abandonment information.

Then, the call control processor 104 of the telephone set R
Returns the state of the own line to the idle state S1, and controls the display unit 34 to return both the red lamp and the green lamp of the corresponding line state indicator of the own line to the off state.

In the other ISDN telephones that have received the D channel packet DP6, the call control processing unit 104 determines that the information of the received packet DP6 is the abandonment information. Then, the call control processing unit 104 of the other ISDN telephone sets
Based on the determination result with the incoming call abandonment information, as shown in FIG. 7, the state of the other line (the line of the telephone R) is returned from the state of receiving another line S13 to the other line idle state S11,
The line status display of the other line corresponding to the line of the telephone R on the display unit 34 returns the red lamp and the green lamp to the off state.

Next, during an incoming call, the IS
A case will be described in which another ISDN telephone T in the group performs a response operation to the incoming call and a transfer request is made before the incoming call response is made on the DN telephone R.

The ISDN telephone R that has received a call is in its own line receiving state S4, and all other I
In the SDN telephone, when the status of the other line corresponding to the incoming ISDN telephone is “other line incoming”, the other IDN
It is assumed that the user presses a line selection button indicating that another line is being received at any ISDN telephone T among the SDN telephones. Then, in the control unit 100 of the other ISDN telephone T, the operation input decoding unit 10
3, the button operation is determined, and the call control processing unit 104
Calls the telephone number of the ISDN telephone set R corresponding to the incoming line from the storage unit 35, controls the packet switching processing unit 101, and receives the incoming call by the D channel packet DP11 as shown in FIG. The transfer request information is transmitted to the ISDN telephone set R of the above.

In the transfer request information of the D channel packet DP11, the identification information of the ISDN telephone T which has requested the transfer is included as the transfer destination information. As the identification information, for example, the telephone number of the transfer request source itself is used. In addition, since the telephone number of another ISDN telephone is stored in each ISDN telephone, if the identification information is such that the stored own telephone number can be read by another ISDN telephone, The telephone number need not be used as the identification information.

The ISDN that sent this transfer request
In the telephone set T, the call control processing unit 104 shifts the state of the other line from the state of receiving another line S13 to the state of requesting transfer S14, controls the display unit 34, and controls the other unit corresponding to the ISDN telephone R. Make the line status indicator of the line blink the green lamp.

In the ISDN telephone set R in the own-line incoming call receiving state S4, the D-channel packet DP11 is received by the packet switching processing unit 101. Then, the call control processing unit 1
At 04, it is determined that the information of the received packet DP11 is transfer request information from another telephone, and the telephone number of the transfer destination (the telephone number of the telephone T which issued the transfer request) is determined from the transfer request information. Information is also extracted.

Then, as shown in FIG. 6, in the telephone set R, the call control processing unit 104 controls the circuit switching message processing unit 102 to send a call transfer request message CM1 of the call transfer service of the ISDN network to the network. I do. The call transfer request message CM1 includes the telephone number of the ISDN telephone T that has transmitted the transfer request as a transfer destination. However, the caller telephone number included in the incoming call information to the ISDN telephone R and the telephone number of the transfer source ISDN telephone R are not included in the message CM1.

Then, after transmitting the call transfer request message CM1 to the ISDN network 4, the ISDN telephone set R returns the call control processing unit 104 of the telephone set R to the idle state S1 and displays the line. The unit 34 is controlled to return both the red lamp and the green lamp of the line status indicator corresponding to the own line to the off state.

On the other hand, the ISDN telephone T which has issued the transfer request
Then, the state of the own line is changed from the idle state S1 to the transfer requesting state S5 by the internal message "Transfer standby" MS1 corresponding to the operation of the line selection button of the other line corresponding to the ISDN telephone set R that has received the call. Then, the call control processing unit 104 controls the display unit 34 to set the line status indicator of the own line to a state in which a green lamp blinking transfer request is in progress.

Then, the state S during the transfer request of the own line is
When there is an incoming call to the ISDN telephone T that has issued the transfer request of 5, the telephone T automatically responds to this incoming call and goes off-hook. Then, the call control processing unit 104
From the storage unit 35, all the other I
The telephone number of the SDN telephone is called, the packet switching processor 101 is controlled, and the busy information is transmitted to all the ISDN telephones other than the telephone T by using the D channel packet DP7.

The control section 100 of the telephone set T changes the line state of its own line from the transfer request state to the busy state S3 by the transfer completion internal message MS2.
The state of the other line corresponding to the ISDN telephone set R is changed from the state of requesting transfer S14 to the idle state S11. Then, the display unit 34 is controlled so that the line status indicator of the own line is turned on by the green lamp, and the line status indicator of the other line corresponding to the ISDN telephone R is turned off by the red and green lamps. .

Then, in all the other ISDN telephones including the ISDN telephone R that has received the D channel packet DP7, the state of the other line corresponding to the ISDN telephone T is set to the state in which the other line is in use, and displayed in the same manner as described above. The unit 34 is controlled by the control unit 100, and the line status indicator of the other line corresponding to the ISDN telephone T is turned on by the red lamp.

As described above, an incoming call to any telephone in the group can be answered by any other telephone. For example, when there is an incoming call from any ISDN telephone 0 connected to the ISDN network 4 shown in FIG. 2 to the ISDN telephone 2, the other ISDN telephones 1 FIG. 1 shows a sequence in a case where a response to an incoming call to the telephone number 2 is made by operating a corresponding other line selection button.

First, when an outgoing call from the telephone 0 to the telephone 2 is made to the ISDN 4, the ISDN 4
An incoming call is made to the telephone 2. This incoming call includes the caller number of telephone 0, that is, the telephone number.

As described above, the telephone 2 that has received the incoming call sets the line status indicator of its own line to the flashing red lamp indicating that the incoming call is being received, and also receives the incoming call including the identification data such as the telephone number of the telephone 2. The display information is set as the D channel packet DP4, and the telephone
It transmits via the DN network 4. The telephone 1 has an ISDN network 4
, And the line status display corresponding to the line of the telephone 2 in the line status display group of the telephone 1 is changed to the incoming call display with the flashing red lamp.

Next, the telephone set 2 sets the incoming call display information including the identification data of the telephone set 2 to the remaining telephone sets 3 in the group as the D channel packet DP4 in the IS.
It is sent via the DN network 4. The telephone 3 transmits the D channel packet DP4 to the ISDN network 4 in the same manner as the telephone 1.
, And the line status display corresponding to the line of the telephone 2 in the line status display group of the telephone 1 is changed to the incoming call display with the flashing red lamp.

Thus, the fact that there is an incoming call to telephone 2 is also notified to the users of other telephones 1 and 3 in the group.

In this incoming call display state, the user of the telephone 1
When the line selection button of the other line corresponding to the telephone set 2 is pressed, a transfer request including the identification information of the telephone set 1 as a transfer destination is transmitted from the telephone set 1 to the telephone set 2 via the D channel packet DP11 over the ISDN network. Sent through. At this time, the other line status indicator of the telephone 1 corresponding to the telephone 2 changes from the flashing red lamp to the flashing green lamp, and the line status indicator corresponding to the own line of the telephone 1 also flashes the green lamp. And the user is informed that the transfer is being requested.

The telephone 2 receives the D-channel packet DP11 of the transfer request via the ISDN 4 and
A message CM1 of a call transfer request with the transfer destination set to the telephone set 1 is sent to the DN network 4. And phone 2
Deletes the incoming call display on the line status indicator of the own line, and turns off the own line with both the red and green lamps turned off.

Upon receiving the call transfer request message CM1 from the telephone 2, the ISDN network 4 transfers the incoming call to the telephone 2 to the telephone 1 designated by the transfer destination included in the call transfer request. , The incoming call is made to the telephone 1. The telephone 1 which has performed a response operation to the incoming call to the telephone 2 and transmitted the transfer request automatically answers the incoming call. Thus, communication between the telephone 0 and the telephone 1 is started.

[0096] As described above, a plurality of ISDs which are installed at remote positions via the ISDN network and form a group are provided.
The N telephone operates as one wide-area key telephone system.

In the first embodiment described above,
When sending an incoming transfer request message CM1 to the ISDN network from an ISDN telephone that has received a transfer request from another telephone as a data packet, the message C
M1 can include not only the telephone number of the transfer destination but also the telephone number of the telephone of the transfer source that issued the request message CM1.
In the case where the transfer destination telephone number can be included in the incoming call information to the transfer destination ISDN telephone, the transfer destination ISDN telephone that has received the transfer is called the transfer source telephone number in the call reception information. The number makes it possible to reliably recognize that the incoming call is a call for which a transfer request has been made.

In the first embodiment described above,
In the ISDN telephone R that has received the incoming call, when the state of the own line is incoming, there is no response operation on the own telephone, no transfer request from another ISDN telephone, and
When a predetermined period of time has elapsed, the answering machine function is activated, the answering machine automatically responds to the incoming call, transmits the answering machine response message to the other party, activates the function to record the other party's message, waits for the other party to disconnect the line, and waits for the other party to disconnect. You may make it return to the idle state S1.

[Second Embodiment] The hardware configuration of the wide area key telephone system and the ISDN telephone according to the second embodiment is almost the same as that of the first embodiment shown in FIGS. It is the same, and the functional block diagram of the ISDN telephone is the same as that shown in FIG. The second embodiment is different from the first embodiment in processing at the time of incoming call and at the time of transfer.

The following description of the second embodiment focuses mainly on the differences from the first embodiment.

FIG. 8 shows a state transition diagram of the own line in the case of the second embodiment, and FIG. 9 shows a state transition diagram of another line.

In the second embodiment, there is an incoming call to one ISDN telephone R whose own line in the wide area key telephone system is in the idle state S1.
When there is no response operation to the telephone R, an automatic response is made. Alternatively, it automatically responds to the incoming call without waiting for the predetermined time. Then, as shown in FIG. 8, the telephone set R sends a response message CM2 to the ISDN network 4 and acquires a caller number (caller phone number).

Then, the communication between the other party and the telephone set R is started by the automatic response.
Therefore, a voice message such as "Please wait a moment" is sent to the other party. Therefore, in the case of the second embodiment, the control unit 100 of the ISDN telephone includes:
Means for generating and sending the message are provided.

Then, the telephone set R sends out the incoming call display information to all of the other ISDN telephone sets in the group as described above by using the D channel packet DP4 *.
At this time, the incoming call display information of the D channel packet DP4 * includes not only the telephone number of the telephone set R that has received the incoming call but also the caller number.

The other ISDN telephones which have received the incoming call display information by the D channel packet DP4 * change the state of the other line corresponding to the ISDN telephone R which has received the incoming call from the idle state S11 to the incoming state S13. Set the line status indicator of the line so that the red lamp is blinking. Further, the other ISDN telephone stores the caller number in the incoming call display information in a memory for confirming the incoming call after the transfer request.

When the display indicating that an incoming call is being made to another line is being performed, the other line selection button corresponding to the incoming ISDN telephone R is set to an arbitrary one of the other ISDN telephones T. When the operation (response operation) is performed, a transfer request is transmitted from the telephone set T to the telephone set R by a D-channel packet D11 in exactly the same manner as in the first embodiment.

In the second embodiment, simultaneously with the transmission of the transfer request, the caller number of the incoming call stored in the memory is called out as the internal message “waiting for transfer” MS3. Then, the telephone T shifts to the transfer requesting state S14, and as described above, the telephone R
Make the line status indicator of the other line corresponding to the green line blink. Further, in the telephone set T, the line status indicator of the own line is also turned on and off by the green lamp in response to the internal message MS3, and the state of the own line is transited to the state S5 in which the transfer is requested.

When receiving the transfer request from the telephone T, the ISDN telephone R suspends the incoming call response, and sets the transfer destination to the telephone T to transmit the in-communication transfer request message CM3.
Send to SDN network. Then, the telephone R changes its own line state to the idle state S1.

The ISDN network which has received the call transfer request message CM3 from the telephone set R causes the telephone set T which has performed the answering operation to receive the held call. State S during transfer request
The telephone T receiving the incoming call on its own line, which is the caller ID No. 5, transmits the caller ID included in the incoming call and the internal message “transfer standby” M
The caller numbers obtained as S3 are compared, and if they match, it is determined that the call is the one requested by the user. If they do not match, it is determined that the call is not the one requested by the user but is another incoming call. (Judgment step JD1 in FIG. 8).

When it is determined that the call is requested by itself, the call control processing unit 104 of the telephone set T stores all the other ISDNs constituting the group from the storage unit 35.
The telephone number of the telephone is called, and the packet switching processing unit 10
1 is transmitted to all other ISDN telephones except the telephone T by using the D channel packet DP7.

In the same manner as in the first embodiment, the control unit 100 of the telephone set T changes the line state of its own line from the transfer request to the busy state S3 by the transfer completion internal message MS2. The state of the other line corresponding to the ISDN telephone R is changed from the transfer requesting state S14 to the idle state S11, the display unit 34 is controlled, and the line state indicator of the own line is turned on by a green lamp. , The line status indicators of the other lines corresponding to the ISDN telephone R are turned off in both red and green lamps.

When it is determined that the incoming call is not a request call but another incoming call, it is determined whether or not there is a free line (determination step JD2 in FIG. 8).
At this time, the call control processing unit 104 of the telephone set T stores all the other ISDNs constituting the group from the storage unit 35.
The telephone number of the telephone is called, and the packet switching processing unit 10
1 to control all other ISDN telephones except the telephone T to transmit the incoming call display information by the D channel packet DP8, and shift to the state S4 of receiving the own line.

If it is determined in step JD2 that there is no free line, a call rejection message CM4 is sent to the ISDN network, and the state of transfer requesting state S5 is continued.

Other operations are the same as those of the first embodiment.

As in the case of the sequence of FIG. 1 of the first embodiment, when there is an incoming call from any ISDN telephone 0 connected to the ISDN network 4 shown in FIG. FIG. 10 shows a sequence according to the second embodiment in a case where another ISDN telephone 1 responds to an incoming call to telephone 2 by operating a corresponding other line selection button.

In the second embodiment, when an incoming call is received by telephone 2, telephone 2 automatically answers. And
While the telephone 0 and the telephone 2 are communicating (in FIG. 10, communication is indicated by being surrounded by a hexagon), incoming display information including the caller number is transmitted from the telephone 2 to another telephone by the D channel packet DP4 *. Send to 1 and 3.

Then, by the response operation on the telephone 1, the transfer request is transmitted by the D-channel packet DP11 to the ISDN.
When transmitted from the telephone 1 to the telephone 2 via the network 4, the telephone 2 suspends the communication with the telephone 0 and sends a transfer request during communication to the ISDN network instructing the telephone T as a transfer destination. Then, the ISDN 4 causes the telephone 1 to receive the call from the telephone 0. As described above, after confirming whether or not the call is a request call by comparing the caller ID, the telephone T automatically responds, and communication between the telephone 0 and the telephone 1 is started.

In the case of the second embodiment, a telephone which has issued a transfer request in response to an incoming call to another telephone certainly confirms whether the incoming call after the request is the requested call. can do.

[Third Embodiment] The hardware configuration of the wide area key telephone system and the ISDN telephone according to the third embodiment is also substantially the same as that of the first embodiment shown in FIGS. It is the same, and the functional block diagram of the ISDN telephone is the same as that shown in FIG. The third embodiment is different from the first and second embodiments in processing at the time of incoming call and at the time of transfer.

In the third embodiment, as in the second embodiment, an automatic answer is made to an incoming call, but the automatic answer is caused by a response operation of another telephone to the incoming call. This is performed after a transfer request is issued.

FIG. 11 shows the operation sequence of the main part of the third embodiment. In this sequence, as in the above-described two embodiments, any ISDN telephone 0 connected to the ISDN network 4 shown in FIG.
When there is an incoming call, another ISDN telephone 1
In this case, a response to an incoming call to the telephone set 2 is made by operating a corresponding line selection button of another line.

The sequence shown in FIG. 11 of the third embodiment is such that the telephone 1 sends a transfer request to the telephone 2 by a response operation and the telephone 2 receives the transfer request via the ISDN 4. This is exactly the same as the case of the first embodiment shown in FIG.

In the third embodiment, the telephone 2 which has received the transfer request from the telephone 1 automatically responds to the incoming call from the telephone 0 and suspends it. After that, similarly to the second embodiment, a communication transfer request instructing the telephone set T as a transfer destination is transmitted to the ISDN 4. The subsequent sequence is the same as in the second embodiment.

In the case of the third embodiment, unless any one of the telephones in the group performs a response operation, a communication state is not established and useless billing can be prevented.

In the case of the third embodiment,
When the telephone that received the call does not perform a response operation and there is no transfer request from another telephone and the predetermined time has elapsed, the answering machine function is activated and the answering machine responds automatically to send the answering machine response message to the other party. Alternatively, the ISDN telephone may be configured to activate the function of recording the message of the other party, wait for the line disconnection of the other party, and return to the own line idle state S1.

[Fourth Embodiment] Although the first to third embodiments all use the transfer service of the ISDN network, the fourth embodiment uses the ISD
Does not use the transfer service of the N network. In the fourth embodiment, for example, 2B + D in the INS net 64,
The fact that one channel can use two B channels is used.

An ISDN telephone constituting the wide area key telephone system according to the fourth embodiment is not shown in FIG.
A function is provided for connecting the call link on channel 0 and the call link on channel B1.

In the fourth embodiment, when an incoming call arrives at a certain telephone, a call link is formed by automatically answering the call in the same manner as in the second embodiment. And
The incoming call display information is transmitted to the other telephones in a D channel packet. However, in the fourth embodiment, unlike the second embodiment, it is not necessary to determine whether or not the call is a call for which a transfer request has been made. As in the case of the third embodiment, a D-channel packet DP4 may be used.

Thereafter, when there is a transfer request (including the telephone number of the telephone) from another telephone, in the fourth embodiment, the telephone which has transmitted the transfer request receives the incoming B The call is transmitted on the B channel different from the channel. Then, the other telephones requesting the transfer automatically answer and form another call link. Then, the telephone having received the incoming call can connect the two call links and connect the incoming call to the telephone which has issued the transfer request, and can perform communication.

FIG. 12 shows an operation sequence of a main part of the fourth embodiment. In this sequence, as in the above-described two embodiments, any ISDN telephone 0 connected to the ISDN network 4 shown in FIG.
When there is an incoming call, another ISDN telephone 1
In this case, a response to the incoming call to the telephone 2 is made by operating the corresponding other line selection button.

In the sequence shown in FIG. 12, until the telephone 2 receives the transfer request and the call link between telephone 0 and telephone 2 is held, the D-channel packet for transmitting the incoming call display information includes the caller telephone number. Is the same as the sequence in FIG. 10 in the case of the second embodiment, except that DP4 not including

In the fourth embodiment, after holding the communication link between telephone 0 and telephone 2, telephone 2
Makes a call during communication to another telephone B, which is vacant, to the telephone 1 which has transmitted the transfer request. IS
The DN network 4 causes the telephone 1 to receive the call. The telephone 1 requesting the transfer automatically responds to the incoming call. Thus, a communication link is formed between the telephone 2 and the telephone 1, and the telephone 2 connects the two communication links formed. As a result, the telephone 0 and the telephone 1 are communicatively linked, and are in communication.

As a modification of the fourth embodiment, a configuration utilizing a service of a three-party call of the ISDN network can be adopted. That is, in the case of this modification,
After holding the communication link between the telephone 0 and the telephone 2, the telephone 2 receiving the incoming call transmits a service request for, for example, a three-party call in the mixing mode to the telephone 1 which has issued the transfer request by calling during the call. I do. Thereby, the telephone 0 and the telephone 1 can perform communication. In this variant, the ISDN telephone need not have a configuration for connecting two call links.

[0134]

As described above, according to the present invention, a plurality of I / Os installed at multiple points via an ISDN network are provided.
By grouping the SDN telephones by storing the telephone numbers of the other ISDN telephones, when an incoming call is made to any one of the ISDN telephones in the group, any one of the ISDN telephones in the group receives the incoming call. An incoming call can be answered, and a wide area button telephone system can be configured by a plurality of ISDN telephones installed at multiple points via an ISDN network.

In the case of the second aspect of the present invention, when automatically responding to an incoming call and transmitting information on the incoming call to another ISDN telephone using a D channel packet, the caller ID of the incoming call is changed to another ISDN telephone. , It is possible to confirm whether or not the incoming call transferred to the ISDN telephone having issued the transfer request is the call requested by the user.

Further, in the case of claim 4, it becomes possible to construct a wide area key telephone system without using the transfer service of the ISDN network.

[Brief description of the drawings]

FIG. 1 is a first view of a wide area key telephone system according to the present invention;
FIG. 9 is a sequence diagram for describing an incoming sequence of a main part of the embodiment.

FIG. 2 is a system configuration diagram of a wide area key telephone system according to an embodiment of the present invention;

FIG. 3 is a diagram showing an appearance of an embodiment of an ISDN telephone according to the present invention.

FIG. 4 is a circuit diagram of an ISDN telephone according to an embodiment of the present invention;

FIG. 5 is a functional block diagram of a main part of one embodiment of the ISDN telephone according to the present invention.

FIG. 6 is a state transition diagram of an own line of the ISDN telephone according to the first embodiment of the present invention;

FIG. 7 is a state transition diagram of another line of the first embodiment of the ISDN telephone according to the present invention;

FIG. 8 is a state transition diagram of an own line of an ISDN telephone according to a second embodiment of the present invention.

FIG. 9 is a state transition diagram of another line of the second embodiment of the ISDN telephone according to the present invention.

FIG. 10 is a sequence diagram for explaining an incoming sequence of a main part of the second embodiment of the wide area key telephone system according to the present invention.

FIG. 11 is a sequence diagram for explaining an incoming call sequence of a main part of the wide area key telephone system according to the third embodiment of the present invention.

FIG. 12 is a sequence diagram for explaining an incoming sequence of a main part of a fourth embodiment of the wide area key telephone system according to the present invention;

[Explanation of symbols]

 1, 2, 3 ISDN Telephone 4 ISDN Network 11 Handset 12 Body 13 Connection Code 21 Dial Button 22 Line Selection Button Group 22a to 22f Line Selection Button 23 Line Status Display Group 23a to 23f Line Status Display 31 Line Interface Unit 32 Communication unit 33 Operation unit 34 Display unit 35 Storage unit 100 Control unit

Claims (6)

(57) [Claims] 1. An ISDN telephone comprising: a plurality of ISDN telephones installed at multiple points via an ISDN network; each of the ISDN telephones includes: a communication unit; and an operation unit for receiving a button input operation by a user. A storage unit for storing at least the telephone numbers of ISDN telephones other than the own telephone among the plurality of ISDN telephones, and a function of transmitting and receiving a control command for receiving a D-channel packet switching service of the ISDN network; A control unit having a function of decoding by decoding
And a display unit for displaying an incoming state of the N telephone. Each of the control units of the ISDN telephone uses the telephone number of the storage unit when the line of the own telephone arrives. To the ISDN telephone, the incoming information to the line of the own telephone is transmitted as a D-channel packet of the ISDN network. When the user operates a transfer request through the key input operation unit while displaying the state on the display unit, and displaying the incoming call state to another ISDN telephone on the display unit, information on the transfer request is displayed. Is transmitted to the receiving ISDN telephone in the D-channel packet, and the D-channel packet including the transfer request information is transmitted. Upon receiving the door, due call forwarding services ISDN network,
A message requesting the ISDN telephone that sent the transfer request to transfer the incoming call is sent to the ISDN telephone.
A wide area button telephone system for transmitting to a network. 2. An ISDN telephone comprising: a plurality of ISDN telephones installed at multiple points via an ISDN network; each of the ISDN telephones includes: a communication unit; and an operation unit for receiving a button input operation by a user. A storage unit for storing at least the telephone numbers of ISDN telephones other than the own telephone among the plurality of ISDN telephones, and a function of transmitting and receiving a control command for receiving a D-channel packet switching service of the ISDN network; A control unit having a function of decoding by decoding
And a display unit for displaying an incoming state of the N telephone. Each of the control units of the ISDN telephone automatically responds to the incoming call when the line of the own telephone arrives, and the storage unit of the storage unit The other IS using a telephone number
To the DN telephone, the incoming call information to the line of the own telephone and the caller number of the incoming call are transmitted in the D channel packet of the ISDN network, and when the D channel packet including the incoming information is received, the When the incoming state of the ISDN telephone that has transmitted the incoming information is displayed on the display unit, and when the incoming state to another ISDN telephone is displayed on the display unit, the user operates the transfer request through the key input operation unit. , The information of the transfer request is transmitted to the terminating ISDN telephone in the D-channel packet, and when the D-channel packet including the information of the transfer request is received, by the call transfer service of the ISDN network,
A message requesting the ISDN telephone that sent the transfer request to transfer the incoming call is sent to the ISDN telephone.
Sending the call to the network, and determining whether or not the call from the ISDN network after issuing the transfer request is a call for which transfer is requested based on the caller number, and automatically answering the call. A wide area button telephone system characterized in that it is determined whether or not to do so. 3. An ISDN telephone comprising a plurality of ISDN telephones installed at multiple points via an ISDN network, wherein each of the ISDN telephones has a communication unit and an operation unit for receiving a button input operation by a user. A storage unit for storing at least the telephone numbers of ISDN telephones other than the own telephone among the plurality of ISDN telephones, and a function of transmitting and receiving a control command for receiving a D-channel packet switching service of the ISDN network; A control unit having a function of decoding by decoding
And a display unit for displaying an incoming state of the N telephone. Each of the control units of the ISDN telephone uses the telephone number of the storage unit when the line of the own telephone arrives. To the ISDN telephone, the incoming information to the line of the own telephone is transmitted as a D channel packet of the ISDN network, and when the D channel packet including the incoming information is received, the incoming of the ISDN telephone that transmitted the incoming information is received. When the user operates a transfer request through the key input operation unit while displaying the state on the display unit, and displaying the incoming call state to another ISDN telephone on the display unit, information on the transfer request is displayed. Is transmitted to the receiving ISDN telephone in the D-channel packet, and the D-channel packet including the transfer request information is transmitted. Upon receiving the bets, after responding temporarily by transfer service during communication of the ISDN network, and sending the transfer request ISD
A wide area button telephone system, wherein a message requesting N telephones to transfer the incoming call is transmitted to the ISDN network. 4. An ISDN telephone comprising a plurality of ISDN telephones installed at multiple points via an ISDN network, wherein each of the ISDN telephones comprises a telephone call unit and an operation unit for receiving a button input operation by a user. A storage unit for storing a telephone number of at least one of the plurality of ISDN telephones other than the own telephone;
A control unit having a function of transmitting a control command for receiving the D-channel packet switching service of the ISDN network and a function of receiving and decoding the control command; and a display unit for displaying an incoming state of the other ISDN telephone. The respective control units of the ISDN telephone, when receiving a line of the own telephone, to the other ISDN telephone using the telephone number of the storage unit, the incoming information to the line of the own telephone, When the D channel packet containing the incoming information is received and transmitted by the D channel packet of the ISDN network, the incoming state of the ISDN telephone which transmitted the incoming information is displayed on the display unit, and another ISDN is displayed by the display unit. When displaying the incoming call state to the telephone, the user operates the transfer request through the key input operation unit. When the D-channel packet including the transfer request information is received, the information of the transfer request is transmitted to the receiving ISDN telephone in the D-channel packet. After answering and holding the incoming call, the I which sent the transfer request
A wide area button telephone system, wherein another call link is provided with an SDN telephone, and the held incoming call is connected to a call link provided with the ISDN telephone that has transmitted the transfer request. 5. A communication unit, an operation unit for receiving a button input operation by a user, a storage unit for storing a telephone number of another ISDN telephone connected via an ISDN network, and a D channel packet of the ISDN network A control unit having a function of transmitting a control command for receiving an exchange service and a function of receiving and decoding the control command; and a display unit for displaying an incoming state of the other ISDN telephone. The control unit of the ISDN telephone includes: When receiving an incoming call to the own line, sending the incoming information to the other ISDN telephone using the telephone number of the storage unit to the other ISDN telephone in a D channel packet of the ISDN network; When a D channel packet containing information is received, an incoming call state of the ISDN telephone which transmitted the incoming call information is displayed on the display unit. When the user performs a transfer request through the key input operation unit while displaying the incoming call state to another ISDN telephone on the display unit, the information of the transfer request is displayed on the incoming ISDN telephone. Is transmitted in the D-channel packet, and when the D-channel packet including the information of the transfer request is received, the incoming call transfer service of the ISDN network
A message requesting the ISDN telephone that sent the transfer request to transfer the incoming call is sent to the ISDN telephone.
An ISDN telephone for transmitting to a network. 6. A communication unit, an operation unit for receiving a button input operation by a user, a storage unit for storing a telephone number of another ISDN telephone connected via an ISDN network, and a D channel packet of the ISDN network A control unit having a function of transmitting a control command for receiving an exchange service and a function of receiving and decoding the control command; and a display unit for displaying an incoming state of the other ISDN telephone. The control unit of the ISDN telephone includes: When receiving an incoming call to the own line, sending the incoming information to the other ISDN telephone using the telephone number of the storage unit to the other ISDN telephone in a D channel packet of the ISDN network; When a D channel packet containing information is received, an incoming call state of the ISDN telephone which transmitted the incoming call information is displayed on the display unit. When the user performs a transfer request through the key input operation unit while displaying the incoming call state to another ISDN telephone on the display unit, the information of the transfer request is displayed on the incoming ISDN telephone. When the D channel packet containing the information of the transfer request is received, the ISD which responds to the incoming call for itself, suspends the incoming call, and transmits the transfer request
An ISDN telephone, wherein another telephone link is provided with the N telephone, and the held incoming call is connected to a telephone link provided with the ISDN telephone that has transmitted the transfer request.