JPH0927849A - Communication terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain redialing with one action from a callee side to a caller. SOLUTION: This terminal equipment is provided with a means 13 sending/ receiving caller number information (e.g. telephone number of caller), a call control signal including callee number information and an information signal, an memory 40 storing the caller number information in the call control signal at the arrival of a call, a switch 43 for re-communication request. When the switch 43 is operated after interruption of line after the reception of the call, a dial signal is sent to a terminal equipment having the caller number information stored in the memory 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal device suitable for application to, for example, an ISDN terminal device.

[0002]

2. Description of the Related Art For example, some conventional telephones using an analog line have a redial function. When this redial function is used, it is convenient to operate the one-touch redial key when redialing to the other party who made the final call, so that the trouble of redialing while looking at the telephone number list can be saved.

[0003]

However, the conventional redial function is effective only when the calling side makes a redial call, and there is a disadvantage that the called side cannot make a one-touch call to the last called party. Therefore, for example, in the case where the line is disconnected during the meeting by telephone and then the called party of the previous call is called to continue the meeting, the called party may call the called party on the telephone number list, etc. Therefore, it was troublesome to find out the telephone number of the calling side.

In view of the above problems, an object of the present invention is to enable one-touch redial from the incoming call side to the outgoing call side.

[0005]

A communication terminal device according to the present invention comprises means for transmitting and receiving a call control signal and information signal including calling number information (for example, a telephone number of a calling party) and called number information, and a means for receiving a call. The calling number stored in this memory has a memory for storing the calling number information in this call control signal and a switch for requesting re-communication, and when this switch is operated after a call is received and the line is disconnected. A signal for making a call is transmitted to a terminal having information.

According to the present invention, since the calling party number information of the last incoming communication is stored in the memory, it is possible to redial from the receiving side to the transmitting side by operating the switch. .

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a communication terminal device according to the present invention will be described below with reference to the drawings. This example is I
The present invention is applied to a communication terminal of SDN (Integrated Services Digital Network).

FIG. 2 shows an example of the ISDN network configuration. In FIG. 2, 1 is an ISDN (hereinafter, also simply referred to as "network"), and this network 1 is an ISDN arranged at each telephone station. Communication speed of exchanges 2A and 2B is 64 kb
B-channel circuit switching network 3 of ps, communication speed 384k
A high speed circuit switching network 4 such as bps (H0 channel), a packet switching network 5 and a common line signaling network 6 for transmitting control signals and the like are connected to each other.

A user's home 8 is connected to the ISDN exchange 2A via a subscriber line 7 composed of a two-wire metallic wire.
A DSU (Digital-data Service Unit) 9A in A is connected, and DSUs 9B, 9C ... Are connected in parallel with this DSU 9A. Similarly, the ISDN exchange 2B has a DS
U10A, 10B, 10C ... are connected and these DS
U9A, 9B ... And DSU10A, 10B .. function as a network terminator (NT) of the network 1.

In the user's house 8A, the DSU 9
A bus line 13 having a transmission line 11 and a reception line 12 and made of a 4-wire metallic wire is derived from A, and a digital telephone 14A, a computer 14B, a G4 type facsimile 14C and a terminal adapter (TA: Terminal) are provided on the bus line 13. Adapter) 14D, non-I
The SDN terminals 15 are connected in parallel in a 1: N wiring (bus wiring) format.

This interface is the smallest basic interface defined by ISDN, and this basic interface is logically two B's as shown in FIG.
It is composed of channels 16A and 16B and one D channel 17, and B channels 16A and 16B are 64 kbp each.
It transmits various user information bidirectionally at the communication speed of s,
The D channel 17 bidirectionally transmits call control information (call origination, termination, etc.) mainly for circuit switching and packet switching at a communication speed of 16 kbps.

However, since the signals of these (2B + D) channels are physically transmitted on one bus line in a time division manner, the nominal bit rate including control bits is 1.
It is 92 kbps.

Further, the communication protocol, which is generally a promise regarding the exchange of control information between a communication device and a communication network, is classified into several layers in appropriate functional units in order to facilitate expansion of communication functions. It is convenient and one of such classification methods is O by ISO (International Organization for Standardization).
There is a seven-layer standard protocol model standardized as an SI (Open System Interconnection) reference model.

FIG. 4 shows an example of a structure in which the ISDN user / network interface is hierarchized according to its standard protocol model. FIG. 4 shows a terminal device (TE: Terminal Endpoint) such as a digital telephone.
18 and 19 are network 1 via DSUs 9A and 10A, respectively.
, The terminal device 18 is connected to the layer 1 (20).
A), layer 2 (20B), layer 3 (20C) and layers 4 to 7 (20D), and the network 1 is layer 1
(21A), Layer 2 (21B), Layer 3 (21C)
Similarly, the terminal device 19 is also composed of seven layers of 22A to 22D.

Among these seven layers, the protocols from layer 1 to layer 3 are defined for the ISDN user / network interface, and layer 1 (physical layer)
Defines the electrical and physical conditions such as pin arrangement for connecting the terminal device to the network, Layer 2 (data link layer) defines the procedure such as detection and recovery of transmission errors occurring in the communication process, layer 2 3 (network layer) defines a method for transferring data between terminal devices via a network.

The information in layers 1 to 3 is S respectively.
_{In the case of 1 to} S ₃ , the information S _{1 of the} layer 1 is transmitted by AMI (Alternate Mark Inversion) code with 100% pulse width, and specifically, the low level “0” is represented by a positive or negative pulse. , High level "1" is represented without a pulse. Further, the information S ₁ has a frame structure of 48 bits (250 μs at 192 kbps) as shown in FIG. 5, and FIG. 5A shows a frame structure when it is transmitted from the DSU to the terminal device (TE), and FIG. Shows the frame structure when transmitted from the terminal device to the DSU.

In FIG. 5, F is a framing bit, L is a DC balanced bit, D is a D channel bit, E is a D echo channel bit, FA is an auxiliary frame bit, N is an inverted bit of FA, and B1 is the first bit. 1 B channel bit string, B2 is second B channel bit string, A
Is a bit used for activation, S is a spare bit, and M is a multi-framing bit.

The layer 1 information S ₁ is classified into an INFO signal having the meaning shown in Table 1.

[0019]

[Table 1]

The INFO signal shown in Table 1 is used to activate the layer 1 as described later. Further, the information S ₂ used in the layer 2 has a higher frame format than the signal S _{1 of the} layer 1, and the main frame types of the information S ₂ of the layer 2 and their contents are summarized in Table 2. Show.

[0021]

[Table 2]

In Table 2, the user information is transmitted through the B channel in the information transfer frame (I frame), but the I frame and the unnumbered frame (U frame) for call control are transmitted through the device D channel. Transmitted over.
The SABME command of the U frame is used to set the data link between the terminal device and the network side to the multi-frame confirmation operation mode, which is the layer 2 numbered information transfer frame. This is an operation mode in which I frames are transmitted in numerical order, and if a transmission error occurs, retransmission is performed for recovery. The DISC command is then used to terminate the multi-frame acknowledged mode of operation.

Further, in the information S ₃ used in layer 3, the call control signal of the D channel is classified into the following messages, and each of these messages realizes circuit switching and packet switching in the B channel. It is used for the B channel link setting of.

Call setup message This includes a calling number (telephone number, etc.), a called number, relay network selection information, transfer capability information, etc., and is used for a call setup request. Call setup acceptance message Used to notify that all call setup information has been received. Response message Used to notify the calling party that the called party has accepted the call. Disconnection message Used to request disconnection between terminals. Release message Used for a release request of the information channel or the like after disconnection of the information channel (B channel). Release completion message Used to notify release of information channels.

When the B channel information is transmitted from the terminal device (TE) to another terminal device via the network (ISDN) by using the information of the above layers 1 to 3, The communication operation with the network will be described with reference to FIG.

First, in step 101, for example, when the handset of the terminal device is off-hooked by the operator, the terminal device transmits the layer 1 <INFO 1> signal (see Table 1) to the network side, and the network responds to it in step 102. The <INFO 2> signal of layer 1 is returned. Then, in step 103, the terminal device sends the <INFO
3> signal is transmitted, a layer 2 activation display request signal is transmitted to the network side, and in step 104, the network transmits the <INFO 4> signal to the terminal device side to establish the layer 1 link and the terminal device. Layer 2 of is activated.

Next, the terminal device receives the layer 3 dial setting request for dialing the called number, which is the number on the called side, and in step 105, the SA of layer 2 is set.
The BME command (see Table 2) is transmitted to the network side, and in response to this, the network displays a dial setting display, which is a notice of dial setting, on the circuit system corresponding to layer 3 of the network, and then in step 106 the terminal device. UA command to the side.

As a result, dial setting confirmation indicating that dial setting is possible in the circuit system corresponding to layer 3 of the terminal device is performed, and the link of layer 2 is established. When the frame can be transmitted, layer 3 is activated.

Next, in response to the dialing of the called number by the operator, the terminal device transmits a call setup message of layer 3 including the calling number and the called number to the network side in step 107. The call setup message and the like are transmitted in a layer 2 information transfer frame (I frame). Upon completion of the reception of the layer 3 call setup message, the network transmits a layer 3 call setup acceptance message to the terminal device in step 108.

When the called number is vacant and the receiving side accepts the call, the network transmits a layer 3 response message to the terminal device side (step 108), and layer 3 information transmission on the B channel becomes possible. .

Subsequently, after the information transmission on the B channel is completed in step 110, for example, when the operator puts the handset on the hook, the terminal device transmits a layer 3 disconnection message to the network side in step 111, and in response thereto. When the layer 3 release message is transmitted from the network to the terminal device (step 112), the terminal device transmits the layer 3 to the network side.
Is transmitted (step 113).
The used B channel is released.

Then, in response to the dial release request from the circuit system corresponding to the layer 3 of the terminal device, the terminal device sends the layer 2 DISC command (Table 2) to the network side in step 114.
The network transmits a UA command to the terminal device (step 115) to terminate the multi-frame acknowledged mode of operation at Layer 2.

Next, in step 116, the network transmits a <INFO 0> signal of layer 1 indicating a signalless state to the terminal device (step 116), and in response to this, the terminal device transmits the signal to the network side in step 117. The communication operation ends by transmitting the layer 1 <INFO 0> signal indicating the signal state.

In the operation of FIG. 6, steps 105 to 109 and steps 111 to 115 are D for transmitting the call control signal, respectively.
The transmission is performed via a channel, and the transmission of step 110 is performed via a B channel for information transmission.

FIG. 1 shows the configuration of the control unit of the digital telephone 14A as the terminal device in the example of FIG.
In the figure, reference numeral 30 is a central processing unit (hereinafter referred to as CPU), and this CPU 30 has a working RAM, a program ROM and the like built therein. Further, 31 is a CPU 3 including a data bus, an address bus, a control bus, etc.
0 system bus, and the CPU 30 controls the digital telephone 14A via the system bus 31.

Reference numeral 32 denotes a communication control circuit for performing call control using the information of the D channel. At the time of transmission, the communication control circuit 32 sets the call of the layer 3 including the called number input from the CPU 30 via the system bus 31. A message is generated, this message is converted into a layer 1 signal and is supplied to the multiplexing circuit 34. When receiving a call, the communication control circuit 32 extracts the calling number N ₀ from the received layer 3 call setup message and sends it to the CPU 30.

Reference numeral 33 denotes a serial / parallel conversion circuit for B channel signals, and this conversion circuit 33 is the CPU 3 at the time of transmission.
A parallel B channel signal input from 0 through the system bus 31 is converted into a serial signal and supplied to the multiplexing circuit 34.

In this case, since the B channels are provided for two lines, these two B channels are referred to as B ₁ channel and B ₂ channel, respectively. When receiving, the serial / parallel conversion circuit 33 converts the received serial signals of the B ₁ channel and B ₂ channel into parallel signals, respectively, and supplies the converted signals to the CPU 30 via the system bus 31.

Further, the multiplexing circuit 34 is connected to the serial B ₁
A layer 1 signal having a nominal bit rate of 192 kbps (see FIG. 5) is formed from the channel signal, the B ₂ channel signal, the D channel signal, and the additional signal, and the layer 1 signal is transmitted via the transmitter 35 and the transmission transformer 36 to the DS.
The data is transmitted to the reception line 12 of the bus line 13 of U9A.
On the other hand, when a call arrives, the layer 1 signal transmitted from the network 1 via the DSU 9A is supplied from the transmission line 11 of the bus line 13 to the separation circuit 39 via the reception transformer 37 and the receiver 38.

This separation circuit 39 uses the B-channel signal and the D-channel signal from the layer 1 signal having the format structure of FIG.
Channel signals are separated and supplied to the communication control circuit 32 and the serial / parallel conversion circuit 33, respectively.

In FIG. 1, 40 is the first RA.
M and 41 represent the second RAM, and the first RAM 40
Can store at least one calling party number,
The RAM 41 is capable of storing, for example, 100 calling numbers and the number of incoming calls.

Reference numeral 42 denotes an input / output circuit, and the keyboard 43 is connected to the system bus 31 via the input / output circuit 42.
Connect. The keyboard 43 is provided with a transmitting side redial key and a receiving side redial key. The transmitting-side redial key is used for conventional redialing, and the receiving-side redial key is used for redialing on the receiving side as described later.

The operation of the digital telephone 14A shown in FIG.
As explained, the communication control circuit 32 receives the incoming call.
Included in the "call setup message" of the D channel for call control
Calling party number N₀And the extracted calling number N₀To
It is sent to the CPU 30. This CPU 30 has its calling number N
₀Is written in the first RAM 40 and its calling number N ₀
Check whether is already written in the second RAM 41.
Bell.

When the calling number N ₀ is written in the RAM 41, the CPU 30 increments the number of incoming calls corresponding to the calling number N ₀ by one. Also, the calling number N ₀
Is not written in the second RAM 41 and there is a blank in the second RAM 41, the CPU 30 sets the Chinese character “1” indicating the calling number N ₀ and the number of incoming calls to the blank in the second RAM 41. Write to. On the other hand, the second RA
When there is no blank in M41, the calling number N ₀ is not written.

After the information exchange corresponding to the incoming call is completed and the line is disconnected, the digital telephone 14
When A wants to connect a line to the calling side corresponding to the last incoming call via the network 1, the operator of this digital telephone 14A operates the called side redial key of the keyboard 43.

In response to this, the CPU 30 causes the first RA
The calling number N ₀ being written to M40 reads and sends the calling number N ₀ to the communication control circuit 32, the communication control circuit 32 is "call setup D channel the number N ₀ and the called party number Message ". Then, this "call setting message" is converted into a layer 1 signal and transmitted to the network 1 side, so that the line between the digital telephone 14A and the calling side corresponding to the last incoming call is connected. .

As described above, according to this example, there is an advantage that the callee side can redial the caller side for the last incoming call with one touch.

Further, in this example, when a predetermined period has passed,
The speed dials are registered in descending order of the number of incoming calls (that is, in descending order of incoming frequency) from the calling numbers written in the second RAM 41. Specifically, when the operator inputs a predetermined command from the keyboard 43, the CPU 30 reads the calling numbers from the second RAM 41 in the order of frequency of incoming calls and assigns the shortened codes to the calling numbers. Therefore, according to the present example, there is an advantage that the speed dial can be automatically registered.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0050]

According to the present invention, there is an advantage that the receiving side can redial the calling side with one touch.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a main part of an embodiment of a communication terminal device of the present invention.

FIG. 2 is a block diagram showing a network configuration of ISDN.

FIG. 3 is a diagram used for explaining ISDN.

FIG. 4 is a diagram used to explain ISDN.

FIG. 5 is a diagram used to explain ISDN.

FIG. 6 is a diagram used to explain ISDN.

[Explanation of symbols]

1 ISDN (network), 9A DSU, 13 bus line, 14A digital telephone, 40 first RAM, 4
1 second RAM, 43 keyboard

Claims (1)

[Claims] 1. A means for transmitting and receiving a call control signal including calling number information and called number information and an information signal, a memory for storing the calling number information in the call control signal when receiving a call, and a switch for requesting re-communication. And a signal for sending a call to a terminal having calling party number information stored in the memory when the switch is operated after receiving a line and disconnecting the line. Terminal device.