JPS639720B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a system for accommodating data terminals in a time-division switching system, particularly in a time-division switching system having a time-division communication path, in which data from a plurality of types of data terminals is transmitted as a baseband signal. At least the modem installed in each data terminal and the subscriber line circuit for data terminals can be made common, regardless of the type of data terminal, and the telephone The present invention relates to a method for accommodating data terminals in a time division switching system in which the terminals have substantially the same interface as the terminals and are accommodated in the time division switching system.

2. Description of the Related Art Telephone switching systems having time-division communication paths have been known for a long time, and data terminals are housed in such switching systems to perform switching processing. Conventionally, the following methods have been adopted as methods for accommodating such data terminals. That is, as is generally done in data switching networks, the data information is synchronized with the clock of the switching network and divided into blocks of a predetermined length, and framing bits and signal bits are assigned to each block. Information was added to the subscriber line in a so-called envelope format.

However, in this case, depending on the type of data terminal, devices for speed conversion and signal processing are required on the data terminal side and/or on the subscriber circuit side of the exchange, resulting in system unification. There was a problem with the lack of sex. Furthermore, since the selected signal format was different from that of a telephone, there was a problem with the uniformity of reception processing.

The present invention aims to solve the above problems, and the data terminal accommodating method in the time division switching system of the present invention includes a subscriber circuit for a telephone set corresponding to a telephone subscriber, and a dial/pulse telephone set. and a push-button telephone, and a time-division exchange having a time-division communication path for exchanging sampled signals in synchronization with a predetermined clock through time-division processing. In the system, a subscriber circuit for a data terminal that is commonly provided in multiple types of data terminals is provided for the data terminal, and a character for the data terminal that has substantially the same interface as the above-mentioned telephone receiver for the exchange control section is provided. A base having a receiver and corresponding to each of the plurality of types of data terminals mentioned above, and transmitting base band signals corresponding to the transmission speed of each corresponding data terminal to or receiving from the subscriber line. ·band·
A modem is installed, and baseband
The subscriber circuit for each data terminal is configured to transmit a baseband signal corresponding to the transmission speed of each data terminal on the subscriber line between the modem and the subscriber line for the data terminal. The baseband signal transmitted via the subscriber line is sampled at multiple points in synchronization with the above clock, and in the character receiver for the data terminal, the multiple points are sampled and returned to the baseband signal again. It is characterized by being configured to receive signal characters corresponding to each terminal. This will be explained below with reference to the drawings.

Fig. 1 shows the configuration of an embodiment of a time division switching system to which the present invention is applied, Fig. 2 shows an embodiment of the signal sequence between a data terminal and a switching center, and Fig. 3 shows the configuration of a baseband signal. An explanatory diagram of an embodiment for explaining multi-point sampling for passing through a time-division communication path is shown.

In FIG. 1, 1 is a dial pulse telephone, 2 is a push-button telephone, 3 is a data terminal A, 4 is a data terminal B, and 5 and 5 are base band modems, respectively, which connect each data terminal to a subscriber line. 6 is a subscriber line, 7 is a time division switching center, and 8 and 8 are subscriber circuits for telephones, respectively. Reference numerals 9 and 9 are subscriber circuits for data terminals, which are commonly used for dial/pulse telephones and push-button telephones, and have a common configuration corresponding to each data terminal regardless of the type of data terminal. 10 is a time division communication path, 11 is a push button telephone receiver, 12 is a dial/pulse telephone receiver, 13 is a receiver for data terminal A, 14 is a receiver for data terminal B, and 15 is a switch control. It represents the department.

Before explaining the data terminals, the call connections corresponding to telephones 1 and 2 will be explained. That is, as is well known, when a telephone subscriber, for example, takes off and hooks the telephone 1, the subscriber circuit 8 for the telephone
When the control unit 15 detects the formation of a loop in the subscriber line and determines that a call has been made, the control unit 15 connects the time division communication path 10 to connect the telephone subscriber (telephone 1) to the dial/pulse telephone receiver 12. Set the path. Next, based on the number of the called party received by the receiver 12, the control unit 15 sets a path to connect the calling party and the called party, and a conversation between the two parties is carried out. In this case, the voice information reaches the subscriber circuit 8 in the form of an analog signal and is sampled in the subscriber circuit 8 at the switching unit rate of the time-sharing channel 10, for example 64 Kb/s, and an analog-to-digital conversion takes place. .

In the case of the present invention, it is intended to accommodate various data terminals with substantially the same interface configuration as the telephone call connection described above, and the call (communication) connection is performed as follows. That is, a modem 5 is provided corresponding to each data terminal 3, 4, and a base band modem is used as the modem 5, and a base band modem is used to connect each data terminal 3, 4 to the subscriber line 6.
The system transmits and receives baseband signals at the transmission speed of the corresponding data terminal. When transmitting and receiving the base band signal, for example, when sending it to the subscriber line 6, it is basically enough to send the data information from the corresponding data terminal to the subscriber line 6 side as it is. The configuration is simple and there is no need to vary the configuration depending on the transmission speed of each data terminal. For this purpose, the base band modems 5, 5 shown in FIG. 1 can have a common configuration.

Data terminals 3 and 4 are generally low-speed,
For example, 50b/s, 100b/s, 200b/s, 300b/s
s, 1200 b/s, etc., which is much slower than the above-mentioned switching unit speed of 64 Kb/s for the above-mentioned telephone. For this reason, in the data terminal subscriber circuits 9, 9 shown in FIG. 1, data information transmitted as a baseband signal, for example, is sampled at multiple points using the 64 Kb/s clock. , to match the case of the audio signal corresponding to the above-mentioned telephone set. For this reason, the data terminal subscriber circuits 9, 9 can have substantially the same configuration regardless of the type of data terminal. Furthermore, in the receiver 13 for data terminal A and the receiver 14 for data terminal B,
The interface for the control section 15 is the same as the interface for the control section 15 in the push-button telephone receiver 11 and the dial/pulse telephone receiver 12, so that it is unified with that for the telephone. ing. In the illustrated case, the receiver 13 for data terminal A and the receiver 14 for data terminal B are assumed to exist separately depending on the type of data terminal, but in terms of hardware, multi-point sampling It goes without saying that after inversely converting the above, it is possible to share most of the configuration of the receiver by changing only the operating clock.

FIG. 2 shows an example of a signal sequence between a data terminal and an exchange. In the illustration, T is a transmission line (T line) and R is a reception line (R line).
In the case of the above-mentioned base band modem 5, since the subscriber line is a two-wire system, the subscriber line 6 is set to a two-way transmission system, as will be described later in FIG. While maintaining the same speed, the 1-bit time width is divided into the T section and the R section.

When the calling data terminal makes a call, the control unit 15
detects that the T line becomes logic "1" in the data terminal subscriber circuit 9, and notifies that the selection signal can be sent by setting the R line to logic "1". In response to this, the originating data terminal sends out a selection signal (character dial) via the T line. On the exchange 7 side, this is received by the receiver 13 for data terminal A, and after being decoded by the control section 15, the control section 15 sets the R line of the destination data terminal to logic "1". call. When the data terminal on the destination side responds, it issues an ID signal and an ACK signal to the data terminal on the origination side and the data terminal on the destination side, and data transmission and reception is started between the two data terminals. When a recovery request occurs at the originating data terminal, the exchange instructs the terminating data terminal to disconnect the R line by setting the R line to logic "0" and disconnects the R line from the originating data terminal. Logic "0"
The recovery request is recognized as follows. At the data terminal on the destination side, the T line is also set to logic "0" and disconnection is performed.

During the above-mentioned call connection, the data terminal subscriber circuit 9 shown in FIG.
The signal is sampled at multiple points using the clock of 1, and is passed through the time-division communication path 10.

FIG. 3 shows an explanatory diagram of an embodiment for explaining the operation for this purpose. The figure shows that the data terminal sends out a signal "10110..." via the T line, and at the same time the R
It is shown that a signal "11010..." is transmitted through the line. In this case, as mentioned above, in the base band modem 5, since the subscriber line is a two-wire system, the subscriber line is used as a bidirectional transmission system, and the time width of 1 bit width is used for the T line. It will be divided into R-line and R-line. That is, as shown in FIG. 3, on the subscriber line 6, the contents of the T line are adopted in the section for the T line, and the contents of the R line are adopted in the section for the R line. This state is shown as "1101101100..." as information on the "subscriber line" shown in FIG. but,
Data transfer rate remains unchanged.

In the data terminal subscriber circuit 9, multi-point sampling is performed using the aforementioned switching unit clock of, for example, 64 Kb/s (in the illustrated case, the frequency of the clock is lowered for simplicity). As a result, the information on the subscriber line 6
As shown in the figure "Multi-point sample output", , and passes through the time-division communication path 10. When the character receiver 13 cancels the multi-point samples in step 14, the contents of the subscriber line 6 are restored as shown in the bottom row of FIG. Of course, when data communication is carried out directly between the originating data terminal and the terminating data terminal without going through the character receiver 13 or 14, the data on the subscriber line corresponding to the terminating data terminal is As shown in the information at the bottom of FIG. 3, it is a baseband signal in which logic "1" and logic "0" are inverted.

In the character receiver 13 or 14 or in the destination data terminal, the information of the illustrated T line section is held for one bit width and used as reception information. That is, the information shown at the top of FIG. 3 is reproduced as received information.

As explained above, according to the present invention, it is possible to accommodate a data terminal in substantially the same manner as a telephone. (i) The base band modem has a simple configuration because it can send the data terminal signal as a base band signal to the subscriber line, and (ii) the subscriber circuit for the data terminal is (iii) the installation of character receivers allows the switch controller to follow the same sequence as for push-button and dial-pulse telephone receivers; The ability to process selection signals from data terminals, etc., allows data terminals to be accommodated without significant changes to the architecture of the switching system for telephones.

[Brief explanation of the drawing]

Fig. 1 shows the configuration of an embodiment of a time division switching system to which the present invention is applied, Fig. 2 shows an embodiment of the signal sequence between a data terminal and a switching center, and Fig. 3 shows the configuration of a baseband signal. An explanatory diagram of an embodiment for explaining multi-point sampling for passing through a time-division communication path is shown. In the figure, 1 and 2 are telephone sets, 3 and 4 are data terminals, 5 is a base band modem, 6 is a subscriber line, 7 is a time division exchange, 8 is a telephone subscriber circuit, and 9 is a data terminal. 10 is a time division communication path, 11 and 12 are receivers for telephones, 1
Reference numerals 3 and 14 represent data terminal receivers, and 15 represents an exchange control unit.

Claims (1)

[Scope of Claims] 1. A telephone subscriber circuit corresponding to a telephone subscriber is provided, and a telephone receiver corresponding to both or one of a dial pulse telephone and a push button telephone is provided, and a predetermined circuit is provided. In a time-division switching system having a time-division communication path in which signals sampled in synchronization with a clock are exchanged by time-division processing, a subscriber circuit for data terminals that is common to multiple types of data terminals is used as a data terminal. In addition, a character receiver for data terminals having substantially the same interface as the above-mentioned telephone receiver is provided for the exchange control section, and a character receiver is provided for each of the above-mentioned plurality of types of data terminals, respectively. A baseband signal that transmits or receives a baseband signal corresponding to the transmission speed of a data terminal to or from a subscriber line.
A modem is installed, and baseband
The subscriber circuit for each data terminal is configured to transmit a baseband signal corresponding to the transmission speed of each data terminal on the subscriber line between the modem and the subscriber line for the data terminal. The baseband signal transmitted via the subscriber line is sampled at multiple points in synchronization with the above clock, and in the character receiver for the data terminal, the multiple points are sampled and returned to the baseband signal again. A method for accommodating data terminals in a time division switching system, characterized in that the data terminals are configured to receive signal characters corresponding to each terminal.