JPH06152597A - Digital communication system and terminal - Google Patents

Abstract

PURPOSE:To realize a terminal for communication in the case all terminals to be connected to the same bus are not communicable by controlling the start of processing when receiving a 2nd incoming call message without starting the processing when receiving a 1st incoming call message by a parameter value. CONSTITUTION:The system is provided with an incoming call mode control section 43 which identifies 1st and 2nd incoming call messages, initial setting control section 41 which sets a binary parameter value, and incoming call control section 42 which starts an incoming call message processing in the 1st and 2nd incoming call messages when a parameter value is '0' and does not start the processing of the 1st incoming call message when the value is '1' and starts processing at the reception of the 2nd incoming call message. Therefore, when incoming call mode specification information is set to '1' to use the terminal, the terminal is operated only when a call start message from another terminal connected on the bus is not returned for the 1st incoming call message.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital communication system and its terminal.

[0002]

2. Description of the Related Art Conventionally, when an incoming call is received from the network, the network sends a first incoming call message meaning an incoming call to a terminal and receives a call start message meaning the acceptance of an incoming call from the terminal within a certain period of time. If not, the digital terminal connected to the terminal-network interface having a procedure for resending the second incoming message having the same content as the first incoming message to the terminal receives the first incoming message. The incoming call message processing operation was started both at the time and when the second incoming call message was received.

As a concrete example of the terminal-network interface, there is an interface between the integrated service digital network (ISDN) and the terminal specified in the I series recommendation of the International Telegraph and Telephone Consultative Committee (CCITT). This interface has a digital subscriber line with a bus structure and sends an incoming call message in a broadcast format to all terminals on the bus when a call arrives, and the communication specified by the information in the incoming call message can be performed. Only the terminal sends a call start message to the network to start calling. Then, when an incoming call is made from the network, the network means the first
Second call message having the same contents as the first call message when the call start message indicating the call acceptance is not received from the terminal within a certain time after the call message is transmitted to the terminal. Is being retransmitted to the terminal.

[0004]

When the above-mentioned conventional digital terminal is connected to the integrated service digital network (ISDN) specified in the I-series recommendation of the International Telegraph and Telephone Consultative Committee (CCITT), the same problem occurs. All the terminals connected to the bus process the first incoming call message, and all the terminals that are determined to be able to communicate send a calling start message to the network to start calling. If no terminal determines that communication is possible, no call start message arrives in the network.

Therefore, a terminal (for example, an answering machine) having a function of communicating only when a plurality of other terminals connected to the same bus cannot communicate is realized by the above-mentioned conventional digital terminal configuration. Is not possible.

[0006]

According to the first aspect of the present invention, there is provided a digital communication system, wherein when the network receives an incoming call, the network transmits a first incoming call message, which means an incoming call, to the terminal, and a predetermined time later. A terminal-network interface having a procedure for retransmitting to the terminal a second incoming call message having the same content as the first incoming call message when a call start message indicating acceptance of the incoming call is not received from the terminal. Further comprising a digital terminal connected to the digital terminal, the digital terminal identifying the first incoming call message and the second incoming call message,
When the preset binary parameter value is the first value, the incoming call message processing operation is started both when the first incoming call message is received and when the second incoming call message is received. When the parameter value is a second value, the incoming call message processing operation is not started when the first incoming call message is received, and the incoming call message processing operation is started when the second incoming call message is received. Is characterized by.

In the digital terminal of the second invention, when an incoming call from the network is received, the network transmits a first incoming call message, which means an incoming call, to the terminal and accepts the incoming call from the terminal within a predetermined time. In a digital terminal connected to a terminal-network interface having a procedure for retransmitting a second incoming call message having the same content as the first incoming call message to the terminal when the meaning call initiation message is not received An incoming call mode control unit that distinguishes the first incoming call message from the second incoming call message, an initial setting control unit that sets a binary parameter value in advance, and the parameter value is a first value. In this case, the incoming call message processing operation is started both when the first incoming call message is received and when the second incoming call message is received, and the parameter value is set to the second value. In this case, the incoming call control unit does not start the incoming call message processing operation when the first incoming call message is received, and starts the incoming call message processing operation when the second incoming call message is received. And

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a digital terminal showing an embodiment of the present invention.

The digital terminal of this embodiment is described as being connected to a home bus having two communication channels a and b and one signal channel c (for example, a basic interface of ISDN user network interface recommended by CCITT). .

FIG. 2 is a block diagram of the home bus in FIG. 1. First, connection of digital terminals will be described. Figure 2
In, the home bus 1 connects the home termination device 21 terminating the subscriber line 20 from the network 10 to each of the terminals 30 to 3x in a multi-drop format. Home bus 1 has terminals 30 to 3
It is composed of a pair of upstream lines 22 that transfer information from the network 10 to the network 10 and a pair of downstream lines 23 that transfer information from the network 10 to the terminals 30 to 3x.

Next, the configuration and operation of the digital terminal will be described with reference to FIG. In FIG. 1, the upstream line 22 of the home bus 1 is connected to the upstream line interface section 24, and the downstream line 23.
Are respectively connected to the downlink line interface unit 25, and the uplink line interface unit 24 multiplexes the communication channels a and b and the signal channel c and sends them to the uplink line 22. In addition to this, the uplink interface unit 24 also performs reception from the uplink 22 and separation of the monitor signal channel. The downlink interface unit 25 performs reception from the downlink 23 and separation of the communication channels a and b and the signal channel c. The signal channel c is connected to the signal transmitting / receiving unit 3,
The call channels a and b are connected to the terminal-specific function unit 6.
The signal transmitting / receiving unit 3 and the terminal-specific function unit 6 are connected to the control unit 4.

The key input section 5, the display section 7 and the calling section 8 are connected to the control section 4. Here, the terminal-specific function unit 6
Is a generic name of functional blocks unique to the terminal, such as a handset and a recording tape recorder. If the key input unit 5 is included in the terminal-specific function unit 6, the key input unit 5 can also be used as the key input unit 5. The display unit 7
Also, when the display unit is included in the terminal-specific function unit 6, it can be shared with it.

1 and 2, the signal from the network 10 is sent using the signal channel on the down line 23 of the home bus 1. The signal channel c is the downlink interface unit 2
The signal is separated by 5, the signal is extracted by the signal transmitting / receiving unit 3, and the extracted signal is sent to the control unit 4.

On the contrary, when the control unit 4 sends a signal to the network 10, the control unit 4 sends a signal to the signal transmission / reception unit 3, and the signal transmission / reception unit 3 converts the signal into a signal format to be sent to the network 10 and an upstream line interface. Send to section 24. The upstream line interface section 24 multiplexes the communication channels a and b and sends them to the signal channel on the upstream line 22 of the home bus 1.

In addition, from the other terminal on the same home bus to the network 1
The signal sent to 0 is on the up line 22, separated by the up line interface unit 24 as a monitor signal channel, and sent to the control unit 4.

The control unit 4 includes an initial setting control unit 41 and an incoming call control unit 42, and the initial setting control unit 41 includes an incoming call mode control unit 43. The initial setting control unit 41 is activated by a power-on signal from a power supply unit (not shown) or a reset key-on signal from the key input unit 5. The incoming call control unit 42 is activated when the control unit 4 receives a signal from the network 10 according to the above-described signal flow. The incoming call mode control unit 43 is activated during the operation of the initial setting control unit 41.

First, the operation at the time of initial setting will be described. When the initialization control unit 41 receives a power-on signal from a power supply unit (not shown) or a reset key-on signal from the key input unit 5, the call-in mode control unit 43 is always activated.

FIG. 3 is a flow chart showing the operation of the incoming call mode control unit in FIG. In FIG. 3, the incoming call mode control unit 43 sends to the display unit 7 a display signal inviting the user to input the operation mode at the time of receiving the incoming call message (step S31). The information designated by the user is input from the key input unit 5 to the incoming call mode control unit 43 (S3).
2). The incoming call mode control unit 43 stores in the control unit 4 whether this information is "0" or "1" as incoming call mode designation information (S33).

In the following description, normal incoming call message processing is designated when the incoming call mode designation information is "0", and processing is performed for the first incoming call message when it is "1". Suppose that the processing is specified only for the second incoming call message retransmitted.

Next, the operation when the incoming call control unit 42 receives an incoming call message from the network 10 will be described with reference to FIG. FIG. 4 is a flowchart showing the operation of the incoming call control unit in FIG.

When the incoming call control unit 42 receives the incoming call message from the network 10, the incoming call control unit 42 first determines whether the incoming call mode designation information is "0" or "1" (S41), and the incoming call is received. If the mode designation information is "1", it is determined whether the received message is the first incoming call message or the retransmitted second incoming call message (S42).

If the incoming call mode designation information is "0" in S41, or if it is "1" and the second incoming call message is in S42, the following operation is performed. The communication specified by the information in the incoming message (for example, phone / fax specification,
Determine whether you can specify circuit switching / packet switching, etc.)
If it is possible, a call start message is returned to the network 10 (S
43), a calling start signal is sent to the calling unit 8 (S4).
4). The call start message is sent to the signaling channel on the home bus 1 according to the signal flow described above.

When the incoming call mode designating information is "1" in S41 and the first incoming call message is in S42, the received message is accumulated (S45), and thereafter the processing completion display for this incoming call is displayed (S46). Do nothing except The accumulated messages are discarded after a certain period of time (a time obtained by adding a slight margin to the incoming message retransmission interval determined by the network 10).

Therefore, in this embodiment, if this incoming call mode designation information is set to "1" and this digital terminal is used,
This terminal operates only when no call start message is returned from another terminal connected to the same bus in response to the first incoming call message, and is given priority over other terminals. Can be lowered.

[0025]

As described above, the present invention facilitates non-priority incoming call processing to a plurality of terminals on the same bus, which is impossible with conventional terminals, by utilizing the retransmission procedure of the terminal / network interface. And it has a remarkable effect that it can be provided economically.

Further, since it can be set to both the normal terminal and the non-priority terminal, it has the effect of being versatile.

[Brief description of drawings]

FIG. 1 is a block diagram of a digital terminal showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of a home bus in FIG.

FIG. 3 is a flowchart showing an operation of an incoming call mode control unit in FIG.

FIG. 4 is a flowchart showing an operation of an incoming call control unit in FIG.

[Explanation of symbols]

 1 Home Bus 3 Signal Transmitter / Receiver 4 Controller 5 Key Input 6 Terminal Unique Function 7 Display 8 Caller 20 Subscriber Line 21 Home Terminator 22 Upline 23 Downline 24 Uplink Interface 25 Downlink Interface 30 , -3x terminal 41 initial setting control unit 42 incoming call control unit 43 incoming call mode control unit

Claims (2)

[Claims] 1. When an incoming call is received from the network, the network sends a first incoming call message meaning an incoming call to the terminal and receives a call start message meaning the acceptance of an incoming call from the terminal within a certain period of time. If not, a digital terminal connected to the terminal-network interface having a procedure for resending the second incoming message having the same content as the first incoming message to the terminal is provided, and the digital terminal is First
Of the first incoming call message and the second incoming call message, and the preset binary parameter value is the first
In the case of the value of, the incoming call message processing operation is started both when the first incoming call message is received and when the second incoming call message is received, and the parameter value is set to the second value.
In the case of the value of, the digital communication system is characterized in that the incoming call message processing operation is not started when the first incoming call message is received, and the incoming call message processing operation is started when the second incoming call message is received. . 2. When an incoming call is received from the network, the network sends a first incoming call message meaning an incoming call to the terminal and receives a call start message meaning the acceptance of an incoming call from the terminal within a certain period of time. If not, the first incoming call is made in the digital terminal connected to the terminal-network interface having a procedure for resending the second incoming message having the same content as the first incoming message to the terminal. An incoming call mode control unit that distinguishes between a message and the second incoming call message, an initial setting control unit that sets a binary parameter value in advance, and the first value if the parameter value is the first value. The incoming call message processing operation is started both when the incoming call message is received and when the second incoming call message is received, and when the parameter value is the second value, the first incoming call message is received. An incoming call control unit that does not start the incoming call message processing operation when the second incoming call message is received and starts the incoming call message processing operation when the second incoming call message is received.