JPS6312422B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention uses a line/packet selective communication system, more specifically, in a digital switching network, to communicate by selectively switching a terminal to a line switching mode or a packet switching mode based on an instruction from a terminal or a switch. Regarding the method.

Circuit switching networks and packet switching networks exist as digital switching networks, but conventionally, terminals are fixedly accommodated in a specific network. FIG. 1 is a diagram showing a conventional terminal accommodation system, where 1, 2, 3, and 4 are terminals,
5, 6, 7, 8 are home line termination devices, 9, 10,
11 and 12 are subscriber lines, 13 is a circuit exchange, and 14
is a packet switch. The terminals 1 and 2 are fixedly housed in a line exchange 13 via in-home line termination devices 5 and 6 and subscriber lines 9 and 10.
4 is the home line terminal device 7, 8, subscriber line 11, 1
2, it is fixedly housed in the packet exchange 14. When joining a switching network, a user selects and joins one of the networks.

For users of data exchange networks, the communication method (line or packet) can be switched for each call or during a call, depending on the type of communication (conversational type, file transfer type, etc.), the amount of communication information, and the communication partner. There are times when you want to communicate using In order to realize such communication mode selection using the conventional technology, it is necessary to simultaneously provide terminals 1 and 3 accommodated in each network as shown in FIG. , terminals, etc. are required, which is inconvenient in use. FIG. 2 is a diagram showing another connection example according to the prior art, in which 15 is a terminal having a common connection procedure for the line exchange 13 and the packet exchange 14, and 16 is a changeover switch. In this connection example, a terminal 15 is connected to a line switching network, line termination devices 5, 7 compatible with a packet switching network, and subscriber lines 9, 1.
1 is prepared, and the communication mode is changed by switching the network using the changeover switch 16. In the example shown in FIG. 2, subscriber lines and line termination devices are required for each of the circuit switching network and the packet switching network, which is uneconomical.

The present invention accommodates one terminal in both a circuit switching equipment and a packet switching equipment via one subscriber line and a communication mode switching device, and selectively switches between circuit switching mode communication and packet switching mode communication for each call or even during a call. The purpose is to economically provide both line and packet communication modes.

Next, the present invention will be explained with reference to the drawings.

FIG. 3 is a block diagram showing the connection configuration of the first embodiment of the present invention, in which 17 is a terminal, 18 is a network control device, 19 is a line termination device, 20 is a communication mode switching device, and 21 is a subscriber line. It is. In this embodiment, the communication mode switching device 20 is provided independently of the exchange. The network control device 18 includes an operation section for requesting communication mode switching, a display section for displaying the status of the communication mode, a signal transmitting/receiving circuit for transmitting and receiving signals for switching the communication mode, and a control section.

The subscriber line 21 is a communication channel (a communication path for transmitting call control signals between the terminal 17 and the circuit switch 13 or the packet switch 14 and data signals between the terminals) and a control channel (a communication channel for transmitting a call control signal between the terminal 17 and the line switch 13 or the packet switch 14 and a data signal between the terminals) This is a multiplex transmission path for transmitting signals by multiplexing them with the device 20 (a communication path for transmitting control signals related to communication mode switching requests) by the line termination device 19. The communication mode switching device 20 connects the terminal 17 and the circuit switch 13 or the terminal 17 and the packet switch 14 based on control signals from the network control device 18 or the circuit switch 13 or the packet switch 14. The procedure will be explained using the sequence diagram FIG. 4. In FIG. 4, solid lines are signals on the communication channel, and dotted lines are signals on the control channel.

Case 1: When switching from circuit switching mode to packet switching mode at the user's request, for example, when the communication mode switching device 20 is set to circuit switching mode and the terminal 17 is in a communicable state in circuit switching mode, network control is performed. When switching to packet switching mode upon request from device 18.

The communication mode switching device 20 is set to the line switching mode, and the terminal 17 and the line exchange 13 are in a ready state where they can make or receive a call, and the ready signal 22
is exchanged between the terminal 17 and the line exchange 13. The network control device 18 and the communication mode switching device 20 are in a ready state in which they can transmit and receive control signals, and ready signals 23 are being exchanged. Network control device 18
sends packet exchange mode designation signal 2 to the control channel.
4 to the communication mode switching device 20. When the device 20 receives the packet switching mode designation signal 24, it switches the communication mode and connects the terminal 17 and the packet switch 14. Communication mode switching device 20
is a switching completion signal 25 indicating completion of communication mode switching.
is notified to the network control device 18 using the control channel. As a result, the communication channel between the terminal 17 and the packet exchange 14 becomes ready, and the ready signal 22 is exchanged between the terminal 17 and the packet exchange 14. The communication channel to the line exchange 13 is in a ready state with the communication mode switching device 20, and a ready signal 22 is exchanged between the communication mode switching device 20 and the line exchange 13. The terminal 17 becomes ready to make a call in the packet exchange mode, and the communication mode selection is completed.

Switching from packet switching mode to circuit switching mode can be realized in the same way.

Case 2: When switching from packet switching mode to line switching mode in response to an instruction from the exchange, for example, when the communication mode switching device 20 is set to packet switching mode and the terminal 17 is in an empty state where it can communicate in packet switching mode. When switching to circuit switching mode based on instructions from circuit switching equipment 13.

Since the communication mode switching device 20 is set to the packet switching mode, the terminal 17 and the packet switching device 14 are in a ready state, and the ready signal 22 is being exchanged between the terminal 17 and the packet switching device 14.
When the communication mode switching device 20 detects the incoming call signal 26 from the line exchange 13, it switches the communication mode, connects the terminal 17 and the line exchange 13, and transmits the incoming call signal 26-1 to the terminal 17. The communication channel to the packet switch 14 is connected to the communication mode switching device 2.
0 and becomes ready state, and the communication mode switching device 20
A ready signal 22 is exchanged between the packet switch 14 and the packet switch 14. Note that switching to the packet switching mode based on an instruction from the packet switching device 14 can be realized in the same manner.

Case 3: As a second example of switching the communication mode based on an instruction from the exchange, the communication mode switching device 20 is set to the packet switching mode, and the terminal 17 receives a call from the circuit switching 13 while communicating in the packet switching mode. If it gets hot.

The terminal 17 is talking through the packet switch 14, and a data signal 26-2 is being transmitted between the terminal 17 and the packet switch 14. The communication mode switching device 20 receives the incoming call signal 26 from the circuit exchange 13.
When detecting this, the device 20 sends a circuit-switched incoming call indication signal 27 to the network control device 18 using the control channel. The network controller 18 receives the circuit switched incoming call indication signal 27 and indicates the incoming call from the circuit switch 13. When the terminal 17 ends communication in the packet switching mode and accepts an incoming call from the circuit exchange 13, the terminal 17 sends a disconnection signal 28 to the packet exchange 14, and receives a disconnection confirmation signal 29 from the packet exchange 14. It receives the data, terminates communication in the packet exchange mode, and enters the empty state of the packet exchange mode. Thereafter, as in case 2, switch the communication mode and connect the terminal 17 and line exchange 13 to receive the incoming call signal 2.
6-1 is transmitted to the terminal 17.

When the terminal 17 continues communication in the packet exchange mode, it does not send out the disconnection signal 28, but instead sends an incoming call rejection signal 30 from the network control device 18 to the control channel. When the communication mode switching device 20 receives the incoming call rejection signal 30, it sends the incoming call rejection signal 30- to the line exchange 13 in response to the incoming call signal 26.
Sends 1. As a result, the state between the line exchange 13 and the communication mode switching device 20 becomes ready for the line exchange mode. Note that switching from circuit switching mode to packet switching mode can be realized in the same way.

In addition, as an application example of Case 3 above, the communication channel between the communication mode switching device 20 and the packet switch 14 is not disconnected, and the data signal transfer state (state in which the data signal 26-2 can be sent and received) is maintained, but temporarily. It is also possible to perform communication in circuit switching mode by applying the above technology.

Furthermore, a method of immediately rejecting an incoming call during communication without displaying an incoming call display can be realized by applying the technology described above.

FIG. 5 shows the signal format between the multiple subscriber line 21 and communication mode switching device 20 and the line exchange 13 or packet exchange 14. 31 is a synchronization bit (F bit), 31-1 is a data bit (D bit), 31-2 is a state control bit (S bit), and 31-3 is an 8-bit unit (envelope).
It is time to switch. Switching timing 31-3
is the timing when the signal from the terminal 17 is applied to the communication mode switching device 20 so as not to break the envelope synchronization when switching the signal from the line switch 13 to the packet switch 14 or vice versa, and this timing is detected by the F bit pattern. .

FIG. 6 shows a block diagram of a configuration example of a communication mode switching device 20 that implements this embodiment. 32 encodes the encoding format of the signal on the multiple subscriber line 21 in the device 20.
a code conversion circuit that converts the signal into the coded format;
33 is a separation circuit for the communication channel and control channel on the multiplex subscriber line 21; 34 is a signal generation circuit for sending signals to the circuit exchange 13 and the packet exchange 14; a ready signal generation circuit 35; and an incoming call rejection signal generation circuit 36. , a selection circuit 37, an F bit generation circuit 38, an S bit generation circuit 39, and an envelope signal assembly circuit 40. Reference numeral 41 denotes a selection circuit which selects either the signal transmitted from the terminal 17 through the communication channel or the signal transmitted from the signal generation circuit 34 under control from the control circuit 45, and sends the selected signal to the line exchange 13. 42 and packet switching equipment 14; and a selection circuit 44 that selects one of the signals sent from line switching equipment 13 and packet switching equipment 14 and sends it to terminal 17. 46 is a multiplexing circuit that multiplexes the communication channel and the control channel onto the multiple subscriber line 21; 47 is a code conversion circuit that converts the signal from the multiplex circuit 46 into the encoded format of the signal on the multiple subscriber line 21; It is. Reference numeral 48 denotes a signal transmission/reception circuit, which receives and analyzes control signals related to communication mode requests transmitted from the network control device 18 through the control channel, and a signal reception analysis circuit 49 that assembles control signals to be sent to the network control device 18. Call origination and recovery signals, as well as line switching equipment 13 and packet switching equipment 14, are transmitted as call control signals on the communication channel from assembly transmitting circuit 50 and terminal 17 to circuit switching equipment 13 and packet switching equipment 14.
It consists of a detection circuit 51 for incoming call and recovery signals as call control signals from. 52 is a clock supply circuit.

When the communication mode switching device 20 is set to the circuit switching mode, the terminal 17 and the circuit switching device 13
is in the ready state (exchanging the ready signal 22), the selection circuit 42 transmits the signal from the terminal 17 to the circuit exchange 13, and the selection circuit 44 transmits the signal from the terminal 17 to the circuit exchange 1.
It functions to transmit signals from 3 to terminal 17.
A ready signal generation circuit 35 is connected to the packet switch 14.
and ready signal 22 from S bit generation circuit 39
The envelope signal assembling circuit 40 assembles the data bit (D bit) indicating the state control bit (S bit), the state control bit (S bit), and the synchronization bit (F bit) from the F bit generation circuit 38 into an envelope signal, and the ready signal 22 is sent to the selection circuit 43. Send it through.
For example, if it is a ready signal specified in CCITT Recommendation In addition, if it is a ready signal specified in Recommendation
It is 0.

When the user requests to change the communication mode (for example, sends the packet exchange mode designation signal 24) (case 1 in FIG. 4). The packet exchange mode designation signal 24 transmitted on the control channel is received and analyzed by the signal reception analysis circuit 49, and is notified to the control circuit 45. The control circuit 45 determines processing based on the current state (ready state between the terminal 17 and the line exchange 13) and the received signal, instructs the selection circuits 42, 43, and 44 to switch modes, and also instructs the signal assembly and transmission circuit 5.
0 to notify completion of switching. Signal assembly and transmission circuit 50
assembles a switch completion signal 25 and communicates it to the transmission network controller 18 on the control channel through the multiplexing circuit 46. As described above, the terminal 17 and the packet exchange 14 are connected, and the ready signal 22 is exchanged between them.

The communication mode switching device 20 is set to packet switching mode, and the terminal 17 and the packet switching device 1
4 is in ready state (exchange ready signal 22)
When a call is received from the line exchange 13 at the same time as in the case (Case 2 in FIG. 4). Signal detection circuit 51
The incoming call signal 26 is detected and notified to the control circuit 45. The control circuit 45 determines the processing based on the current state (ready state between the terminal 17 and the packet switch 14) and the received signal, and selects the selection circuit 4.
2, 43, and 44 to switch modes. As a result, the terminal 17 and the line exchange 13 are connected, and the incoming call signal 26-1 is transmitted to the terminal 17.

When the terminal 17 receives a call from the circuit switch 13 while communicating through the packet switch 14 (case 3 in FIG. 4). The signal detection circuit 51 is case 2
Similarly, the detection information is notified to the control circuit 45. The control circuit 45 determines processing based on the current state (the terminal 17 and the packet exchange 14 are communicating) and the received signal, instructs the signal assembly and transmission circuit 50 to send the incoming call display signal 27, and performs signal assembly. Transmission circuit 5
0 sends the signal 27 to the network controller 18. When receiving the call rejection signal 30 from the network control device 18, the signal reception analysis circuit 49 receives and analyzes it, and notifies the control line 45. The control circuit 45 sends the call rejection signal 30 - 1 from the call rejection signal generation circuit 36 to the line exchange 13 . In addition, call rejection signal 3
When communication in the packet switching mode is terminated by an instruction from the terminal 17 instead of sending 0, a ready signal 22 is sent between the terminal 17 and the packet switching equipment 14.
is replaced, and the operation is the same as in case 2 above.

Although the above example shows a case where the communication mode switching means is an independent device, it is also possible to add a communication mode switching means within the circuit switch 13 or the packet switch 14 and control the mode switching by the control device of the switch. It is. In this case, the signal transmitting/receiving circuit 48 is connected to the line exchange 13 or the packet exchange 1.
The function of the control circuit 45 can be realized by the control device of the line exchange 13 or the packet exchange 14. Further, the function of the selection circuit 41 can also be realized by an exchange switch of the line exchange 13.

In the first embodiment shown in FIG. 3, the control signal related to the communication mode request is transmitted through a communication channel and another control channel. As a second embodiment, a control signal related to a communication mode request is also transmitted through a communication channel, and the communication mode switching device 20
A system for operating the terminal 17 and connecting the circuit switch 13 or the packet switch 14 will be explained with reference to FIG. FIG. 7a is a block diagram of a second embodiment of the present invention, and FIG. 7b is a sequence diagram.

When the communication mode switching device 20 is set to the line switching mode, the ready signal 22 is exchanged between the terminal 17 and the line exchange 13, as shown in the sequence diagram of FIG. 7b. In order for the terminal 17 to communicate in the packet exchange mode, it is necessary to connect the terminal 17 and the packet exchange 14 and to exchange ready signals 22.

Terminal 17 sends a call signal 53 to line exchange 13. The line exchange 13 receives the call signal 53 from the terminal 1.
7 detects a call, connects the communication channel of the terminal 17 to the dial receiving circuit and sends a dial ready signal 54.
is sent to the terminal 17. When the terminal 17 receives the dial enable signal 54, it sends a communication mode change request to the circuit exchange 13 using a dial signal 55 predetermined as a communication mode designation signal. When the line exchange 13 receives the dial signal 55 (communication mode change request), it identifies the communication mode change request, sends a confirmation signal 56 indicating that the signal has been received to the terminal 17, and then sends a disconnection instruction signal 5
Sends 7. The terminal 17 sends a disconnection confirmation signal 58 and disconnects once. The line exchange 13 sends a communication mode change signal 59 to the communication mode switching device 20. The communication mode switching device 20 receives the communication mode change signal 59 from the line exchange 13, switches the selection circuit 41, and sends a switching completion signal 60 to the line exchange 13. When the selection circuit 41 of the communication mode switching device 20 operates, the terminal 17 and the packet switch 14 become ready, and the communication mode change is completed.

This second embodiment eliminates the need for a control channel and therefore eliminates the need for network controller 18 compared to the first embodiment shown in FIG.

Although the case where the communication mode switching device 20 is controlled by the line exchange 13 has been described above, control from the packet exchange 14 is also possible.

In this method, the communication mode switching means is
A terminal 17 and a line switch 13 or a terminal 17 and a packet switch 14 can be connected by providing the terminal 17 and the line switch 13 or the terminal 17 and the packet switch 14, and communication can be performed using the respective switching systems. This is applicable to the terminal 17 having the following connection procedure. Further, in the case of terminals having different connection procedures, according to the present invention, the connection can be realized by the connection shown in FIG. 61 is line exchange 13
62 is a terminal that has a connection procedure to the packet exchange, and 63 is a changeover switch. When a communication mode request is made to the communication mode switching device 20, signals are transmitted and received between the communication mode switching device 20 and the changeover switch 63, and the changeover switch 63 is operated in synchronization with the communication mode changeover, thereby adjusting the connection procedure of the exchange. It is also possible to communicate with each compatible terminal.

As explained above, according to the present invention, it is possible to select between circuit switching mode communication and packet switching mode communication on each call or during a call in accordance with a request from a terminal or exchange. This has the effect of economically realizing the most suitable communication method depending on the communication type (conversational type, file transfer type, etc.), the amount of communication information, and the communication partner by sharing the subscriber line terminal device.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a conventional terminal accommodating system in a digital switching network, FIG. 2 is a diagram of a different terminal accommodating system according to the prior art, and FIG. 3 is a block diagram showing the connection configuration of the first embodiment of the present invention. FIG. 4 is a sequence diagram of the communication mode request procedure in the embodiment of FIG.
Fig. 5 is a diagram showing a signal format, Fig. 6 is a block diagram of a configuration example of a communication mode switching device, Fig. 7a
is a block diagram showing the connection configuration of the second embodiment of the present invention, FIG. 7b is a sequence diagram of the communication mode request procedure in the second embodiment, and FIG. FIG. 3 is a connection diagram of an embodiment of the invention. 1, 2, 3, 4... terminal, 5, 6, 7, 8...
In-home line termination device, 9, 10, 11, 12... Subscriber line, 13... Line exchange, 14... Packet switch, 15... Terminal, 16... Changeover switch, 17... Terminal, 18... Network control device, 19...
...Line termination device, 20...Communication mode switching device,
21...Subscriber line, 22, 23...Ready signal,
24...Packet exchange mode designation signal, 25...
Switching completion signal, 26, 26-1...Incoming call signal, 2
6-2...Data signal, 27...Circuit-switched incoming call display signal, 28...Disconnection signal, 29...Disconnection confirmation signal, 30, 30-1...Incoming call rejection signal, 31...
Synchronization bit, 31-1...Data bit, 31-
2...Status control bit, 31-3...Switching timing, 32...Code conversion circuit, 33...Separation circuit, 34...Signal generation circuit, 35...Ready signal generation circuit, 36...Call rejection signal generation circuit, 37
...Selection circuit, 38...F bit generation circuit, 39
... S bit generation circuit, 40 ... Envelope signal assembly circuit, 41, 42, 43, 44 ... Selection circuit, 45 ... Control circuit, 46 ... Multiplexing circuit, 4
7... Code conversion circuit, 48... Signal transmission/reception circuit,
49... Signal reception analysis circuit, 50... Signal assembly and transmission circuit, 51... Detection circuit, 52... Clock supply circuit, 53... Calling signal, 54... Dial ready signal, 55... Dial signal, 56 ... Confirmation signal, 57 ... Disconnection instruction signal, 58 ... Disconnection confirmation signal, 59 ... Communication mode change signal, 60 ... Switching completion signal, 61, 62 ... Terminal, 63 ... Changeover switch.

Claims (1)

[Claims] 1 In a digital switching network that accommodates digital terminals that send and receive digital information and selectively provides either circuit-switched communication or packet-switched communication to the digital terminals using a circuit switch or a packet switch, the digital terminal A communication mode switching means for switching between communication by switching and communication by packet switching is provided in the digital switching network, and the communication mode switching means can receive an instruction from the exchange even from an instruction given from a digital terminal. A line/packet selective communication system characterized by being configured to switch the communication mode of a digital terminal even from an instruction.