JPH09186775A - Wide area key telephone system and isdn telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To build up the wide area key telephone system equivalent to that plural ISDN telephone sets located at multi-points via an ISD network build up one key telephone system. SOLUTION: Each of ISDN telephone sets stores telephone numbers of the plural ISDN telephone sets being components of a wide area key telephone system at its storage section. When an incoming call comes to a line of its own telephone set, the telephone number stored in the storage section is used to send incoming call information to other ISDN telephone sets by a D channel packet of the ISD network. The other ISDN telephone sets receiving the D channel packet display the incoming call state of the ISDN telephone set sending the incoming call information on their display sections. When the user makes an operation of a transfer request in the other ISDN telephone sets, the information of the transfer request is sent to the ISDN telephone set receiving an incoming call in the D channel packet. The ISDN telephone set receiving the D channel packet of transfer request sends information of requesting to the ISDN so as to transfer the receiving call to the ISDN telephone set sending the transfer request by the transfer service of the ISD network.

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 and installed at a plurality of points.
The present invention relates to a button telephone system including a DN telephone (hereinafter referred to as a wide area telephone telephone system) and an ISDN telephone used for this system.

[0002]

2. Description of the Related Art In a general button 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 the button telephone of
Controls calls between extension telephones (extension calls).

In the key telephone system, when an incoming call through the telephone network is received at any of the telephones in the system,
You can answer with any phone in the system.
However, the conventional button telephone system can realize its function within the range of a plurality of button telephones that can be connected to the main device by a cable. For example, a telephone call from the head office in Tokyo to a branch office in Osaka. I couldn't get it.

There is a transfer function as a method for linking persons in such remote places. 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, one specific transfer destination telephone number is registered in advance in the answering machine. When the answering machine receives an incoming call, this answering machine makes a temporary reply and redials to the telephone set with the preset telephone number. The transfer function is realized by linking calls.

Further, in the case of the ISDN network, the above-mentioned call forwarding function can be realized by utilizing the call forwarding service of the ISDN network without making a temporary response. Also in this case, the user sets a telephone number of a specific transfer destination in the ISDN telephone in advance. Then, when the ISDN telephone receives an incoming call from the network through the D channel, if no one answers the incoming call for a certain period of time or if the telephone is in use, the preset setting is made. Redial (transfer request) the phone with the same phone number. Then ISDN
Based on this transfer request, the network transfers the incoming call to the transfer destination telephone number.

In this way, between two telephones connected via the telephone network, even if they are located far from each other,
Call transfer can be performed.

[0008]

By the way, when an incoming call is received by one of a plurality of telephones distributed at a plurality of points distant from each other via a telephone network, the plurality of telephones are called in response to the incoming call. If any of the telephones can respond, a wide area button telephone system equivalent to one button telephone system constructed by these plural telephones can be constructed, which is very convenient.

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

However, in the case of the transfer function of the answering machine and the transfer service of the ISDN network described above, only one telephone set can receive the transfer at a time. Therefore, even if the transfer function or transfer service described above is used, when an incoming call arrives at any one of a plurality of phones distributed over three or more places via the telephone network. However, it is not possible to realize a function capable of responding to an incoming call with any one of these plural telephones.

An object of the present invention is to realize a wide area button telephone system as described above, and to provide an ISDN telephone that constitutes this wide area button telephone system.

[0012]

A wide area button 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 call unit, an operation unit that receives a button input operation by a user, and a storage unit that stores the telephone numbers of at least other ISDN telephones among the plurality of ISDN telephones. A control unit having a function of sending 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, and the other ISD
A display unit for displaying the incoming call status of the N telephone, and each control unit of the ISDN telephone uses the telephone number of the storage unit to receive the incoming call to the line of the own telephone. To the ISDN telephone set, the incoming call information indicating that there is an incoming call on the line of the own telephone is sent out as a D channel packet of the ISDN network,
When a D channel packet including the incoming call information is received, the incoming call status of the ISDN telephone that has transmitted the incoming call information is displayed on the display unit, and the incoming call status to another ISDN telephone is displayed on the display unit. When the user performs a transfer request operation through the key input operation unit during the operation, the transfer request information is sent to the IS of the incoming call.
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 service of the ISDN network causes the ISDN telephone that has transmitted the transfer request to receive the incoming call. A message requesting that the IS
It is characterized in that it is transmitted to the DN network.

[0013]

In the present invention having the above structure, a plurality of ISDN telephones connected to the 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 an ISDN telephone set A in the group receives an incoming call, the telephone set A sends to all the other ISDN telephone sets the incoming call information indicating that the telephone set A has arrived by a D channel packet. To be done.

The other ISDN telephones which have received the D channel packet including the information of the incoming call to the telephone A display on the display unit that the telephone A is in the incoming call state. As a result, all the ISDN telephones in the group notify their respective users that the ISDN telephone A in the group has received a call.

Then, when another ISDN telephone set in the group indicates that the other ISDN telephone set is in the incoming call state, when the response operation is performed by the other ISDN telephone set, the incoming call is received by the other ISDN telephone set. be able to.

That is, one ISDN telephone B is connected to another I
When responding to the incoming call to the SDN telephone A, the control unit of the telephone B sends the information of the transfer request to the I
D channel packet is sent to SDN telephone A.

When the ISDN telephone set A receives this D channel packet, it sends a call transfer request message containing the telephone number of the ISDN telephone set B as a transfer destination to the ISDN network.

Upon receiving the transfer request message for the call transfer, the ISDN network makes an incoming call to the ISDN telephone set A.
Transfer to SDN phone B. Therefore, an incoming call to any one ISDN telephone set A in the group can be answered by any other ISDN telephone set B in the same group as this telephone set A, and it can be transmitted over an ISDN network. Grouped ISDNs in remote locations
It is possible to realize a wide area button telephone system that causes a telephone to function as a single button telephone system.

[0019]

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

[First Embodiment] FIG. 2 shows an overview of the entire wide area button telephone system according to the first embodiment. The wide area button telephone system according to the first embodiment is as follows. A plurality of ISDN telephones 1, 2 and 3 in this example, which constitute one group, are connected to the line L respectively.
It is configured to be connected to the ISDN network 4 via 1, L2 and L3.

The grouping of the three ISDN telephones 1, 2, and 3 is performed because each of the telephones 1, 2, and 3 stores the telephone numbers of the other telephones in the group in the storage unit. The telephone number is stored, for example, by the user or by a telephone builder. In FIG. 2, the telephone set 0 connected to the ISDN network 4 is an ISDN telephone set outside the group. However, the storage unit may store the telephone numbers of all ISDN telephones including the telephone numbers of its own telephone.

In this embodiment, as will be described later, it is possible to respond to an incoming call to a line to which all the ISDN telephones in the group constituting the wide area 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. FIG. 3 shows its external appearance, and FIG. 4 shows its circuit configuration.

As shown in FIG. 3, the IS of this embodiment is
The DN telephone comprises a handset 11, a telephone body 12, and a connection cord 13 connecting the handset 11 and the telephone body 12. The telephone body 12 is provided with a dial button 21 including a number button, “*” button, and “#” button, a line selection button group 22, and a line status indicator group 23.

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

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

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

Line selection button 22a: B0 of own line L1
Channel selection button 22b for capturing the channel B1 channel for capturing the local line L1 Channel selection button 22c: Answering an incoming call to the B0 channel of the other line L2 Line selection button 22d: An incoming call to the B1 channel of the other line L2 For response line selection button 22e: For response of 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 indicator group 23 comprises 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, and the lines to which the respective line selection buttons 22a to 22f are assigned are receiving or in use. Display the line status such as transferring.

To display the line status, each of the line status indicators 23a to 23f has a built-in red lamp and green lamp. Then, the lighting and blinking states of these lamps indicate the following line states.

Red lamp is lit: Other telephone is in use Red lamp is blinking: Incoming call is received to another line Green lamp is lit: Own telephone is in use Green lamp is blinking: Transfer is in progress.

Then, 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, like the line selection buttons 22a to 22f.

Line status indicator 23a: B0 of own line L1
Channel status display 23b: Status display of B1 channel of own line L1 Line status display 23c: Status display of B0 channel of other telephone 2 Line status display 23d: Status display of B1 channel 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-23f
When the line selection buttons 22a to 22f are set, each line status indicator automatically displays the line status of the adjacent line selection button. Is to 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 is
A control unit 100 equipped with a microcomputer, and a line interface unit 31, a call unit 32, an operation unit 33, a display unit 34, and a storage unit 35, which are controlled by the control unit 100, are provided.

The line interface unit 31 is connected to the ISDN line L, and the ISDN line L and the control unit 10 are connected.
It controls the exchange of data with 0 and ISDN.
It controls the exchange of a call voice signal between the line L and the call section 32.

The call section 32 includes the handset 11, the received voice is emitted from the speaker of the handset 11, and the voice transmitted by the microphone of the handset 11 is transmitted to the line interface section 31. Via the ISDN line L.

The operation unit 33 includes a hook switch corresponding to on-hook and off-hook by raising and lowering the handset 11.
It 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 the control unit 100.
To supply.

The control section 100 discriminates which button is operated from the button operation signal, and performs control according to the button operation. Although not shown in FIG. 3 for simplification of description and because it is not related to the present invention, when the operation unit 33 includes a button for speed dial and an operation button for one-touch dial. There is also.

The display unit 34 includes the line status indicator group 23, and the display control signal from the control unit 100 causes the above-mentioned red and green lamps of the line status indicators 23a to 23f to be turned on or blinking. Controlled.

The storage unit 35 stores the telephone numbers of at least other ISDN telephones in the above-mentioned group. In the case of this embodiment, three ISDN telephones 1, 2,
The telephone numbers other than the own telephone of 3 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 other ISDN telephones to be grouped so as to constitute the wide area button telephone system are set in the storage unit 35 by the operator or the user himself who installs the telephones. Remembered.

In the present invention, the wide area button telephone system is realized by utilizing the D channel packet switching service. To configure the wide area button telephone system, the control unit 100 of each ISDN telephone sets the D channel packet system. It has the function of transmitting and receiving.

FIG. 5 is a functional block diagram showing, among the processing functions of the control unit 100, particularly the processing function portions that realize the essential parts of the present invention.

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

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

The packet exchange processing unit 101 also receives a D channel packet from another telephone through the line interface unit 31 and supplies it to the call control processing unit 104. Then, the packet switching processing unit 101 determines that another ISD
Information on the state of the N telephones is sent to the call control processing unit 104.

The circuit switching message processing unit 102 transmits / receives a line effect message such as an outgoing call, an incoming call, a response, and a transfer request to / from the ISDN network based on a control signal from the call control processing unit 104. Then, the line exchange message processing unit 102 determines the line state of the own telephone (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.
A button operation input including a hook operation by the user is received through, and which button is pressed is determined, and the determination result is supplied to the call control processing unit 104.

The call control processing unit 104 receives the information on the status of the other telephone from the packet switching processing unit 101, the information on the own line status from the circuit switching message processing unit 102, and the determination result from the operation input decoding unit 103. , Display 3
No. 4 of the line status indicators 23a to 23f is supplied with a display control signal for controlling the lighting and blinking of the display lamps to the display unit 34, and if necessary, the telephone of another ISDN telephone stored in the storage unit 35. A control signal for reading the number and transmitting necessary information to the other party of the telephone number by a D channel packet is transmitted to the packet exchange processing unit 101.

In the first embodiment having the above hardware configuration, one ISD in the group
When the N telephone receives an incoming call, the function of the main part of the present invention, which enables the other ISDN telephones in the group to respond to the incoming call, will be described with reference to the sequence diagram of FIG. 1 and FIGS. This will be described below with reference to the line state transition diagram of No. 7.

<Calling> First, the sequence at the time of calling from the ISDN telephone of this embodiment will be described using the line state transition diagrams of FIGS. 6 and 7.

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, both the red lamp and the green lamp of the corresponding line status indicator of the own line are turned off.

In the idle state S1, when the off-hook operation is performed, the own line selection button is pressed, the dial button operation is further performed, and the calling operation is performed,
The call control processing unit 104 of the control unit 100 controls the circuit switching message processing unit 102 to control the line interface unit 3
1 sends a call command to the ISDN network, 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 controls all the other ISDN telephones. In response, 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 ringing state S2, controls the display unit 34, and sets the line state indicator of the own line to the green lamp lit state, Display line busy.

At this time, in the other ISDN telephone, the packet exchange processing unit 101 causes the D channel packet D
Upon receiving P1, the call control processing unit 104 determines that the information of the received packet is the line usage information. The call control processing unit 104 of the other ISDN telephone receives the determination result from the line use information and shifts the line state from the other line idle state S11 to the other line in use state S12 as shown in FIG. The corresponding other line status indicator on the display unit 34 is turned on.

When the user makes an on-hook operation to cancel the call because the other party does not respond to the call, the call control processor 104 of the ISDN telephone sets
From the determination result from the operation input decoding unit 103, the fact is recognized, the telephone numbers of all the other ISDN telephones forming the group are called from the storage unit 35, the packet switching processing unit 101 is controlled, and As shown in 6,
D channel packet DP2 allows all other IS
Abandon midway transmission information is sent to the DN telephone.

Then, the call control processing unit 104 returns the state of the own line to the idle state S1 and controls the display unit 34 to turn 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 other ISDN telephones, the packet exchange processing unit 102 receives the D channel packet DP2, and the call control processing unit 104 determines the information of the received packet as the midway transmission abandonment information. And other ISD
The call control processing unit 104 of the N telephone returns the line state from the state S12 in which another line is in use to the line idle state S11, and displays it, as shown in FIG. The other line status indicator corresponding to the section 34 is returned to the off state of the red lamp and the green lamp.

In the own-line calling state S2 of FIG. 6, when the other party responds to the call, the response information is sent 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 call, controls the display unit 34, and turns on the green lamp of the line state indicator corresponding to the own line. Let At this time, the control unit 100 controls the line interface unit 31 and the call unit 32 to form a call link. The other ISDN telephone continues the state S12 in which the other line is being used.

Then, when an on-hook operation is performed in the ISDN telephone that has originated the call, the call control processor 104
Recognizes that 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
The end call display information is sent 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, and
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 off state.

On the other hand, in other ISDN telephones, the packet exchange 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 call termination display information. Then, the call control processing unit 104 of the other ISDN telephone receives the determination result from the call-end display information, and as shown in FIG. 7, changes the line state from the state S12 in which the other line is being used to the other line idle state S11. Back to
The other line status indicator corresponding to 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 case of the first embodiment will be described with reference to the state transition diagrams of FIGS. 6 and 7. In the following description, among a plurality of ISDN telephones in the group, the ISDN telephone having an incoming call on its own line is referred to as a telephone telephone R, and another ISDN telephone that issues a transfer request for the incoming telephone call is referred to as a telephone 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 through the D channel. Therefore, the control unit 100 of the telephone R receives the message at the circuit switching message processing unit 102 and the call control processing unit 104.
Calls the telephone numbers of all the other ISDN telephones that make up the group from the storage unit 35, controls the packet switching processing unit 101, and uses the D channel packet DP4 to all the other ISDN telephones. Sends the incoming call display information.

The call control processor 104 of the ISDN telephone R that receives the call receives the line status indicator of its own line of the display unit 34 (for simplicity of the following description, for each telephone line, B0 channel, B1 channel The display control signal is sent to the user, the red lamp is blinked, and the speaker is sounded to inform the user that his / her own telephone R is receiving the call, that is, the call is being received on the own line. Inform.

On the other hand, in the other ISDN telephones that have received the D channel packet D4, the call control processing unit 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 is
Based on the discrimination result from 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 incoming state S13 of the other line, and the corresponding other line of the display unit 34 is changed. The line status indicator is made to blink the red lamp and the speaker is sounded to inform the user that the other line where the red lamp is blinking is receiving a call.

In response to an incoming call to the own line of the ISDN telephone R, the line selection button in the operating section 33 of the ISDN telephone R in which the red lamp of the corresponding line status indicator is blinking is operated, and the handset 11 When the off-hook operation is performed by, the operation input decoding unit 103 determines the operation input, and in response to the determination 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. Control call, generate call link and put into call.

Then, the call control processing unit 104 of the telephone set R
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 uses the D channel packet DP5 as shown in FIG. The busy display information is sent to the ISDN telephone. Then, the line state of the own line is shifted to the state S3 during the own line call, and the display unit 34 is controlled so that the line state indicator of the own line which receives the incoming call is in the green lamp lighting state.

On the other hand, in the other ISDN telephones that have 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.
7, the state of the corresponding other line is shifted from the state S13 of receiving the other line to the state S12 of using the other line, as shown in FIG. The line status indicator of the other line corresponding to the line received by the 34 ISDN telephone R is turned on with the 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 this from the determination result from the operation input decoding unit 103, and the storage unit 35. To call the telephone numbers of all the other ISDN telephones that make up the group, control the packet switching processing unit 101, and send all other ISDN telephones by the D channel packet DP3 as shown in FIG. And sends the end call 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 so that both the red lamp and the green lamp of the corresponding line state indicator of the own line are turned off. return.

On the other hand, in other ISDN telephones, the packet exchange 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 call-end display information. Then, 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 set R) to the other state, as shown in FIG. 7, based on the determination result from the call-end display information. Status of line in use S12
From the other line idle state S11,
The red lamp and the green lamp of the line status indicator of the other line corresponding to the above line of the ISDN telephone R are turned off.

When the ISDN telephone set R that has received an incoming call abandons the incoming call without responding to the incoming call, that is, when the other party interrupts the outgoing call, the following occurs.

In the ISDN telephone R, when the control unit 100 determines that the call is abandoned due to the call interruption of the other party in the state S4 while the call is being received by the call control processing unit 104 through the circuit switching message processing unit 102, the call control is performed. The 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 controls the other ISD telephones.
D channel packet DP for all N telephones
In step 6, the incoming call abandonment information is transmitted.

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

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

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

Now, the ISDN telephone set R that has received a call is in the state S4 of receiving a call on its own line, and all other I
In the SDN telephone, when the state of the other line corresponding to the ISDN telephone being called is the other line called, the other I
It is assumed that the user presses the line selection button displaying the incoming call of the other line on any ISDN phone T of the SDN phones. Then, in the control unit 100 of the other ISDN telephone T, the operation input decoding unit 10
The button operation is determined in step 3, and the call control processing unit 104
Calls the telephone number of the ISDN telephone R corresponding to the other line which is receiving the incoming call 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 sent to the ISDN telephone R.

The transfer request information of the D channel packet DP11 includes the identification information of the ISDN telephone set T that is the transfer request source as the transfer destination information. As this identification information, for example, the telephone number itself of the transfer request source is used. Since each ISDN telephone stores the telephone number of another ISDN telephone, if the stored telephone number is identification information that can be read by another ISDN telephone, The telephone number does not have to be 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 other line receiving state S13 to the transfer requesting state S14, controls the display unit 34, and responds to the ISDN telephone R. Make the line status indicator of the line blink green.

In the ISDN telephone set R which is in the incoming state S4 of the own line, the packet switching processing unit 101 receives the D channel packet DP11. Then, the call control processing unit 1
In 04, it is determined that the information of the received packet DP11 is the transfer request information from another telephone, and the transfer destination telephone number (the telephone number of the telephone T that has 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 the incoming call transfer request message CM1 of the incoming call forwarding service of the ISDN network to the network. To do. The incoming call transfer request message CM1 includes the telephone number of the ISDN telephone T that has sent the transfer request as a transfer destination. However, the caller telephone number and the telephone number of the transfer source ISDN telephone R included in the incoming call information to the ISDN telephone R are not included in this message CM1.

Then, after the ISDN telephone set R sends the incoming call transfer request message CM1 to the ISDN network 4, the call control processing section 104 of the telephone set R returns the state of its own line to the idle state S1 and displays it. By controlling the unit 34, both the red lamp and the green lamp of the line status indicator corresponding to the own line are turned off.

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

Then, the state S during the transfer request of this own line is made.
When an ISDN telephone T that has issued a transfer request of 5 receives an incoming call, the telephone T automatically answers the incoming call and goes off hook. Then, the call control processing unit 104
All other I's forming a group from the storage unit 35.
The telephone number of the SDN telephone is called, the packet exchange processing unit 101 is controlled, and the in-use information is transmitted to all other ISDN telephones other than the telephone T by the D channel packet DP7.

Further, the control unit 100 of the telephone set T changes the line state of its own line from the transfer requesting state to the busy state S3 by the transfer completion internal message MS2, and
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. Then, by controlling the display unit 34, the line status indicator of the own line is turned on in the green lamp, and the line status indicators of other lines corresponding to the ISDN telephone R are turned off in both the red and green lamps. .

Then, in all the other ISDN telephones including the ISDN telephone R that received the D channel packet DP7, the state of the other line corresponding to the ISDN telephone T is the state in which the other line is being used and is 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.

As described above, an incoming call to any telephone in the group can be answered by any other telephone. For example, when an ISDN telephone 2 receives an incoming call from an arbitrary ISDN telephone 0 connected to the ISDN network 4 shown in FIG. FIG. 1 shows a sequence in the case where the response to the incoming call for No. 2 is made by operating the corresponding other line selection button.

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

As described above, the telephone set 2 which has received the incoming call sets the line status indicator of its own line to the blinking red lamp indicating the incoming call, and the incoming call including identification data such as the telephone number of the telephone set 2 is received. With the display information as the D channel packet DP4, first the IS is set to the telephone 1 in the group.
It is transmitted via the DN network 4. The telephone 1 is an ISDN network 4
This D-channel packet DP4 is received via the line status indicator corresponding to the line of the telephone 2 in the group of line status indicators of the telephone 1, and the red lamp blinks to indicate the incoming call.

Next, the telephone set 2 similarly sets the incoming call display information including the identification data of the telephone set 2 for the remaining telephone sets 3 in the group as the D channel packet DP4 and the IS.
It is sent via the DN network 4. The telephone 3 transmits this D channel packet DP4 to the ISDN network 4 in the same manner as the telephone 1.
The line status indicator corresponding to the line of the telephone 2 in the group of line status indicators of the telephone 1 is displayed via the red lamp blinking.

As a result, the user of the other telephones 1 and 3 in the group is notified that the telephone 2 has received an incoming call.

In this incoming call display state, the telephone set of the telephone 1 is set so that the user of the telephone 1 can answer the incoming call of the telephone 2.
When the line selection button of the other line corresponding to the telephone 2 is pressed, the telephone 1 sends a transfer request including the identification information of the telephone 1 as a transfer destination to the telephone 2 through the ISDN network with the D channel packet DP11. Sent through. At this time, the other line status indicator corresponding to the telephone 2 of the telephone 1 is changed from the red lamp blinking to the green lamp blinking state, and the line status indicator corresponding to the own line of the telephone 1 is also the green lamp blinking state. The user is informed that the transfer request is being made.

The telephone set 2 receives this transfer request D channel packet DP11 via the ISDN network 4, and
The incoming call transfer request message CM1 having the transfer destination as the telephone 1 is sent to the DN network 4. And telephone 2
Deletes the incoming call display on the line status indicator of the own line and enters the own line idle state with both the red and green lamps off.

Upon receiving the incoming 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 forwarding destination included in the incoming call forwarding request. , Makes an incoming call to the telephone 1. The telephone 1 which has performed the response operation to the incoming call to the telephone 2 and has sent the transfer request automatically answers the incoming call. As a result, communication is started between the telephone 0 and the telephone 1.

As described above, a plurality of ISDs, which are installed at distant positions via the ISDN network and form a group,
The N telephone operates as one wide area button telephone system.

Incidentally, in the above-mentioned first embodiment,
When an ISDN telephone that has received a transfer request from another telephone as a data packet sends an incoming call transfer request message CM1 to the ISDN network, the message C
In the case where M1 can include not only the telephone number of the transfer destination but also the telephone number of the transfer source telephone that has issued the request message CM1, and at the time of transfer, from the ISDN network,
When it is possible to include the transferee telephone number in the incoming call information to the ISDN telephone of the forwarding destination, the ISDN telephone of the forwarding destination that received the incoming call of the forwarding is the telephone of the forwarding origin in the incoming call information. With the number, it is possible to reliably recognize that the incoming call is the call requested to be transferred.

In the above first embodiment,
In the ISDN telephone R that has received the incoming call, when its own line is in the incoming state, there is no response operation on the own telephone, and there is no transfer request from another ISDN telephone.
When a predetermined time or more has passed, activate the answering machine function, automatically answer an incoming call, send an answering machine answer message to the other party, activate the function to record the other party's message, and then wait for the other party to disconnect the line. You may make it return to the idle state S1.

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

The following description of the second embodiment will focus on the differences from the first embodiment.

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

In the second embodiment, there is an incoming call at one ISDN telephone R in which the own line in the wide area 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 the fixed time. Then, as shown in FIG. 8, the telephone set R sends a response message CM2 to the ISDN network 4 and also acquires a caller number (caller telephone number).

Then, by this automatic response, communication is started between the other party and the telephone R. At this time, the telephone R
A voice message such as "Please wait, please" is sent from the other party. Therefore, in the case of the second embodiment, the control unit 100 of the ISDN telephone is
Means for generating and transmitting the message are provided.

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

The other ISDN telephones receiving the incoming call display information by the D channel packet DP4 * change the state of the other line corresponding to the received ISDN telephone R from the idle state S11 to the incoming call state S13, Make the line status indicator of the line blink red. Further, the other ISDN telephone stores the caller number in the incoming call display information in the memory in order to confirm the incoming call after the transfer request.

While the incoming call display to the other line is displayed, the other line selection button corresponding to the ISDN phone R receiving the call is displayed on any one of the other ISDN phones T. When an operation (response operation) is performed, a transfer request is sent from the telephone set T to the telephone set R by the D channel packet D11, just as in the case of the first embodiment described above.

In the second embodiment, at the same time as the transfer request is sent out, the caller number of the incoming call stored in the memory is called as the internal message "standby for transfer" MS3. The telephone set T then shifts to the transfer requesting state S14 and, as described above, the telephone set R.
Set the line status indicator of the other line corresponding to to make the green lamp blink. Also, in the telephone set T, the line status indicator of the own line is also made to blink in the green lamp by the internal message MS3, and the state of the own line is transited to the state S5 in which transfer is requested.

When the ISDN telephone set R receives the transfer request from the telephone set T, the ISDN telephone set R holds the answered incoming call and sets the transfer destination as the telephone set T to the in-communication transfer request message CM3.
It is sent to the SDN network. Then, the telephone set R changes the state of its own line to the idle state S1.

When the ISDN network receives the transfer request message CM3 during communication from the telephone set R, the ISDN network makes the telephone set T which has responded by receiving the call on hold. Status S during transfer request
The telephone set T, which has received an incoming call on its own line of No. 5, has a caller number included in the incoming call and an internal message “waiting for transfer” M
The caller numbers obtained as S3 are compared, and if they match, it is determined that the call is the one requested by itself, and if they do not match, it is determined that the call is not the one requested by itself but another call. (Decision step JD1 in FIG. 8).

When the call control processor 104 of the telephone set T determines that the call is the one requested by itself, the call control processor 104 of the telephone set T stores all the other ISDNs constituting the group from the memory 35.
The telephone number of the telephone is called, and the packet exchange processing unit 10
Controls 1 to send the in-use information to all other ISDN telephones other than the telephone T by the D channel packet DP7.

Further, similarly to the case of the first embodiment, the control unit 100 of the telephone T changes the line state of its own line from the transfer requesting state to the talking state S3 by the transfer completion internal message MS2. The status of the other line corresponding to the ISDN telephone R is changed from the transfer requesting status S14 to the idle status S11, the display unit 34 is controlled, and the line status indicator of the own line is lit with the green lamp. , The line status indicator of the other line corresponding to the ISDN telephone R is turned off.

When it is determined that the incoming call is not the request call but another incoming call, it is determined whether or not there is a free line (decision step JD2 in FIG. 8).
At this time, the call control processing unit 104 of the telephone T concerned stores all the other ISDNs forming the group from the storage unit 35.
The telephone number of the telephone is called, and the packet exchange processing unit 10
Controls 1 to send the incoming call display information to all other ISDN telephones other than the telephone T by the D channel packet DP8, and shifts to the state S4 in which the own line is being called.

When it is judged in the judgment step JD2 that there is no available line, the incoming call rejection message CM4 is sent to the ISDN network, and the state of the transfer requesting state S5 is continued.

Other operations are similar to those of the first embodiment.

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

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

Then, in response to the response operation on the telephone set 1, the transfer request is sent to the ISDN by the D channel packet DP11.
When the data is 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 the in-communication transfer request to the ISDN network instructing the telephone T as the transfer destination. Therefore, the ISDN network 4 makes the telephone set 1 receive the call from the telephone set 0. As described above, the telephone set T automatically confirms whether or not it is a request call by comparing the caller numbers, and then automatically responds, and communication between the telephone set 0 and the telephone set 1 is started.

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

[Third Embodiment] The hardware configurations of the wide area button telephone system and the ISDN telephone according to the third embodiment are almost the same as those of the first embodiment shown in FIGS. The functional block diagram of the ISDN telephone is the same as that shown in FIG. The third embodiment differs from the first and second embodiments in the processing at the time of incoming call and transfer.

In the third embodiment, similarly to the second embodiment, an automatic response is made to an incoming call, but the automatic response is caused by a response operation of the other telephone to the incoming call. It is performed after a transfer request is made.

FIG. 11 shows the operation sequence of the essential parts of the third embodiment. This sequence is also the same as in the above-described two embodiments, any ISDN telephone set 0 to ISDN telephone set 2 connected to the ISDN network 4 shown in FIG.
When there is an incoming call to another ISDN telephone 1
Then, the response to the incoming call to the telephone set 2 is made by operating the line selection button of the corresponding other line.

In the sequence of FIG. 11 of the third embodiment, until 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 network 4, This is exactly the same as the case of the first embodiment shown in FIG.

In the third embodiment, the telephone set 2 which has received the transfer request from the telephone set 1 automatically answers the incoming call from the telephone set 0 and puts it on hold. Then, thereafter, similarly to the second embodiment, the in-communication transfer request instructing the telephone set T as the transfer destination is transmitted to the ISDN network 4. The subsequent sequence is the same as in the case of the second embodiment.

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

In the case of the third embodiment,
When there is no response operation on the phone that received the call, and there is no transfer request from other phones, and when a predetermined time or more has elapsed, the answering machine function is activated and the answering machine answering message is automatically sent to the other party. The ISDN telephone may be configured such that, after the function of recording the message of the other party is activated, it waits for the other party to disconnect the line and returns to the own line idle state S1.

[Fourth Embodiment] The above first to third embodiments all utilize the transfer service of the ISDN network, but the fourth embodiment is the ISD.
Do not use the transfer service of N network. In the fourth embodiment, for example, the INS net 64 is 2B + D,
The fact that two B channels can be used on one line is utilized.

Although not shown, the ISDN telephone which constitutes the wide area button telephone system of the fourth embodiment is
It is provided with a function of connecting a call link on channel 0 and a call link on channel B1.

In the fourth embodiment, when an incoming call arrives at a certain telephone set, an automatic response is made in the same manner as in the second embodiment to form a call link. And
The incoming call display information is transmitted to the other telephone as a D channel packet. However, in the fourth embodiment, unlike the second embodiment, it is not necessary to judge and confirm whether or not the call is a call for which transfer is requested. As in the case of the third embodiment, the D channel packet DP4 may be used.

After that, when there is a transfer request (including the telephone number of the telephone) from another telephone, in the fourth embodiment, the telephone B that has transmitted the transfer request receives the incoming call. The transmission is performed on the B channel, which is different from the channel. The other telephone requesting the transfer then automatically answers and forms another call link. Then, the telephone receiving the call can connect the two call links and connect the incoming call to the telephone that has issued the transfer request to communicate.

FIG. 12 shows the operation sequence of the essential parts of the fourth embodiment. This sequence is also the same as in the above-described two embodiments, any ISDN telephone set 0 to ISDN telephone set 2 connected to the ISDN network 4 shown in FIG.
When there is an incoming call to another ISDN telephone 1
Then, the response to the incoming call to the telephone set 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 withholds the call link between the telephone 0 and the telephone 2, the D channel packet for transmitting the incoming call display information is the caller telephone number. The sequence is the same as the sequence of FIG. 10 in the case of the second embodiment, except that DP4 that does not include is included.

In the fourth embodiment, after the communication link between the telephone 0 and the telephone 2 is put on hold, the telephone 2
Makes an outgoing call during communication to the telephone set 1 which has transmitted the transfer request, by using the other free B channel. IS
The DN network 4 makes the telephone set 1 receive this call. The telephone 1 requesting the transfer automatically responds to this incoming call. Therefore, although a communication link is formed between the telephone 2 and the telephone 1, the telephone 2 connects the two formed communication links. As a result, the telephone set 0 and the telephone set 1 are linked for communication and are in communication.

As a modified example of the fourth embodiment, it is possible to adopt a configuration using a three-party call service of the ISDN network. That is, in the case of this modification,
After holding the communication link between the telephone 0 and the telephone 2, the telephone 2 that receives the incoming call sends a service request for a three-way call in the mixing mode, for example, to the telephone 1 that has issued the transfer request by calling during the call. I do. Thereby, the telephone 0 and the telephone 1 can communicate with each other. In the case of this variant, the ISDN telephone does not have to have a configuration connecting two call links.

[0134]

As described above, according to the present invention, a plurality of I's installed at multiple points through the ISDN network.
By grouping SDN telephones by storing the telephone numbers of other ISDN telephones, when any one of the ISDN telephones in the group receives an incoming call, any ISDN telephone in the group A wide-area button telephone system can be configured by a plurality of ISDN telephones that can respond to incoming calls and are installed at multiple points via the ISDN network.

Further, in the case of the invention of claim 2, when the incoming call is automatically answered and the information about the incoming call is transmitted to the other ISDN telephone by the D channel packet, the caller number of the incoming call is set to the other ISDN telephone. Therefore, it is possible to confirm whether or not the incoming call transferred to the ISDN telephone which has issued the transfer request is the call requested by itself.

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

[Brief description of the drawings]

FIG. 1 is a first wide area button telephone system according to the present invention.
FIG. 7 is a sequence diagram for explaining an incoming sequence of the main part of the embodiment of FIG.

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

FIG. 5 is a functional block diagram of essential parts of an embodiment of an ISDN telephone according to the present invention.

FIG. 6 is a state transition diagram of the own line of the first embodiment of the ISDN telephone according to 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 the own line of the second embodiment of the ISDN telephone according to 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 the incoming sequence of the main part of the second embodiment of the wide area telephone system according to the present invention.

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

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

[Explanation of symbols]

 1, 2, 3 ISDN telephone 4 ISDN network 11 Handset 12 Main body 13 Connection code 21 Dial button 22 Line selection button group 22a-22f Line selection button 23 Line status indicator group 23a-23f Line status indicator 31 Line interface unit 32 Call unit 33 Operation unit 34 Display unit 35 Storage unit 100 Control unit

Claims (6)

[Claims] 1. An ISDN telephone comprising a plurality of ISDN telephones installed at multiple points via an ISDN network, each of the ISDN telephones having a call section and an operation section for receiving a button input operation by a user. A storage unit for storing the telephone numbers of ISDN telephones other than its own telephone among the plurality of ISDN telephones, and a control command transmission function and reception for receiving the D channel packet switching service of the ISDN network. And a control unit having a function for decoding and ISDs other than the above.
And a display unit for displaying the incoming call status of the N telephone set, and each control unit of the ISDN telephone set uses the telephone number of the storage unit when receiving an incoming call to the line of the own telephone set. The incoming call information to the line of the own telephone is sent to the ISDN telephone by a D channel packet of the ISDN network, and when the D channel packet including the incoming call information is received, the incoming call of the ISDN telephone that transmitted the incoming call information is received. When the user performs a transfer request operation through the key input operation unit while the status is displayed on the display unit and the incoming call status to another ISDN telephone is displayed on the display unit, the transfer request information is displayed. Is sent in the D channel packet to the ISDN telephone receiving the call, 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 has sent the transfer request to transfer the incoming call is sent to the ISDN.
Wide-area button telephone system characterized by sending to the network. 2. A plurality of ISDN telephones installed at multiple points via an ISDN network, each of the ISDN telephones having a call section and an operation section for receiving a button input operation by a user. A storage unit for storing the telephone numbers of ISDN telephones other than its own telephone among the plurality of ISDN telephones, and a control command transmission function and reception for receiving the D channel packet switching service of the ISDN network. And a control unit having a function for decoding and ISDs other than the above.
And a display unit for displaying the incoming call status of the N telephone, and each control unit of the ISDN telephone automatically responds to the incoming call when the line of the own telephone is received, Other IS using the telephone number
The incoming call information to the line of the own telephone and the caller number of the incoming call are sent to the DN telephone by the D channel packet of the ISDN network, and when the D channel packet including the incoming call information is received, When the incoming state of the ISDN telephone that has transmitted the incoming call information is displayed on the display unit and the incoming state to the other ISDN telephone is displayed on the display unit, the user operates the transfer request through the key input operation unit. When the D channel packet including the transfer request information is transmitted to the ISDN telephone that is receiving the call, the D channel packet including the transfer request information is received.
The ISDN telephone that has sent the transfer request sends a message requesting the ISDN telephone to transfer the incoming call.
A call received from the ISDN network after being sent to the network and issuing the transfer request is judged based on the caller number to determine whether or not the call is a call requested by itself, and an automatic response is made to the call. A wide area button telephone system characterized in that it is decided whether or not to do so. 3. A plurality of ISDN telephones installed at multiple points via an ISDN network, each of the ISDN telephones having a call section and an operation section for accepting a button input operation by a user. A storage unit for storing the telephone numbers of ISDN telephones other than its own telephone among the plurality of ISDN telephones, and a control command transmission function and reception for receiving the D channel packet switching service of the ISDN network. And a control unit having a function for decoding and ISDs other than the above.
And a display unit for displaying the incoming call status of the N telephone set, and each control unit of the ISDN telephone set uses the telephone number of the storage unit when receiving an incoming call to the line of the own telephone set. When the DDN packet of the ISDN network is transmitted to the ISDN telephone by receiving the incoming call information to the line of the own telephone, and when the D channel packet including the incoming call information is received, the incoming call of the ISDN telephone that transmitted the incoming call information is received. When the user performs a transfer request operation through the key input operation unit while the status is displayed on the display unit and the incoming call status to another ISDN telephone is displayed on the display unit, the transfer request information is displayed. Is transmitted to the ISDN telephone that is receiving the call in the D channel packet, and the D channel packet including the transfer request information. 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 sent to the ISDN network. 4. A plurality of ISDN telephones installed at multiple points via an ISDN network, each of the ISDN telephones having a call section and an operation section for receiving a button input operation by a user. A storage unit for storing the telephone numbers of at least other ISDN telephones other than its own telephone among the plurality of ISDN telephones,
A control unit having a control command sending function 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 the incoming state of the other ISDN telephone are provided. When each of the control units of the ISDN telephones receives an incoming call on the line of its own telephone, it uses the telephone number of the storage unit to inform the other ISDN telephone of incoming call information to the line of its own telephone, When the D-channel packet of the ISDN network is transmitted and the D-channel packet including the incoming call information is received, the incoming call status of the ISDN telephone that transmitted the incoming call information is displayed on the display unit, and the display unit displays another ISDN. When the incoming call status to the telephone is displayed, the user operates the transfer request through the key input operation unit. When the D channel packet including the transfer request information is transmitted to the ISDN telephone receiving the incoming call, the D channel packet including the transfer request information is automatically transmitted to the ISDN telephone receiving the incoming call. After responding and holding the incoming call, the transfer request is sent I
A wide area button telephone system characterized in that another call link is provided between the SDN telephone and the held incoming call is connected to a call link provided between the ISDN telephone that has sent the transfer request. 5. A call section, an operation section for receiving a button input operation by a user, a storage section for storing the telephone numbers of other ISDN telephones connected via an ISDN network, and a D channel packet for the ISDN network. The control unit of the ISDN telephone is provided with a control unit having a function of transmitting a control command for receiving the exchange service and a function of receiving and decoding the control command, and a display unit for displaying the incoming state of the other ISDN telephone. When the incoming call to the own line is made, the incoming call information to the own line is sent to the other ISDN telephone by using the telephone number of the storage unit as a D channel packet of the ISDN network, and the incoming call is made. When a D channel packet containing information is received, the incoming state of the ISDN telephone that has transmitted the incoming information is displayed on the display section. However, when the user makes a transfer request operation through the key input operation unit while the display unit displays the incoming call status to another ISDN phone, the information of the transfer request is sent to the ISDN phone that is receiving the call. When the D channel packet including the information of the transfer request is received, the incoming transfer service of the ISDN network
The ISDN telephone that has sent the transfer request sends a message requesting the ISDN telephone to transfer the incoming call.
An ISDN telephone characterized by transmitting to the network. 6. A call unit, an operation unit that receives a button input operation by a user, a storage unit that stores the telephone numbers of other ISDN telephones connected via an ISDN network, and a D channel packet of the ISDN network. The control unit of the ISDN telephone is provided with a control unit having a function of transmitting a control command for receiving the exchange service and a function of receiving and decoding the control command, and a display unit for displaying the incoming state of the other ISDN telephone. When the incoming call to the own line is made, the incoming call information to the own line is sent to the other ISDN telephone by using the telephone number of the storage unit as a D channel packet of the ISDN network, and the incoming call is made. When a D channel packet containing information is received, the incoming state of the ISDN telephone that has transmitted the incoming information is displayed on the display section. However, when the user makes a transfer request operation through the key input operation unit while the display unit displays the incoming call status to another ISDN phone, the information of the transfer request is sent to the ISDN phone that is receiving the call. When the D channel packet containing the information of the transfer request is received, the ISD that has transmitted the transfer request after responding to the incoming call to itself and holding the incoming call
An ISDN telephone, wherein another call link is provided between the N telephone and the held incoming call is connected to a call link provided between the ISDN telephone that has sent the transfer request.