JPH06350699A - Ring signal transmitting circuit - Google Patents

Abstract

PURPOSE:To increase the number of subscriber lines which can be stored by providing the timing control circuit group which controls the operation timings of ring relay contacts and using a ring signal generator having a certain current driven capability. CONSTITUTION:In the case of the ring signal which is turned on for one second and is turned off for two seconds, the circuit is so constituted that three ring relay contact control lines are inputted to one timing control circuit 5. Even if ring turning-on requests of three lines (n), n+1, and n+2 are simultaneously inputted to the timing control circuit in this state, opportunity for ring turning- on/off is given to each line once for three seconds, and the timing of this opportunity is different among respective lines by one second. Consequently, the ring signal is actually outputted to lines (n), n+1, and n+2 in order even when the ring turning-on/off request is simultaneously inputted to these three lines (n), n+1, and n+2 from PCM-IN. Thus, simultaneous output of ring transmission of three lines does not occur.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subscriber carrier or an exchange subscriber trunk, and more particularly to a ring signal transmission circuit.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional ring signal transmitting circuit is a subscriber signal conversion circuit (SLIC) group 6 for mutually converting an analog connection signal of a subscriber line and a digital information signal. , Digital information signal and P
Subscriber signal conversion circuit control unit 7 for mutually converting the CM signal
And a ring relay contact group 8 for sending a ring signal to a subscriber, and a ring signal generator 9 commonly used for a plurality of subscriber lines for supplying a ring signal.

In such a conventional ring signal transmission circuit, the subscriber signal conversion circuit control unit 7 is provided in the PCM IN.
When the ring-on request for the line n is detected, the contacts assigned to the line n in the ring relay contact group 8 are operated to send the ring signal to the line n. After this arbitrary time, the subscriber signal conversion circuit control unit 7 causes the PCM IN
If a ring-off request for line n is detected,
The ring relay contact 8 is restored and the ring signal transmission to the line n is stopped.

Similarly, according to the ring on / off request for the lines n + 1, n + 2, ..., The corresponding ring relay contact 8 is operated / restored and the ring signal is sent / stopped. At this time, sending / stopping the ring signal for each line operates independently of each other.

[0005]

In this conventional ring signal transmission circuit, the transmission / reception of ring signals to respective lines is performed.
Since the stoppages were realized independently of each other, when the usage rate of each line increases, or as shown in the ring sending timing chart of FIG. 4, there is an extremely random probability that ring signals are sent simultaneously for several lines. A situation occurs that must be done. The maximum number of ring signals that must be sent at the same time (maximum number of simultaneous ring lines) is generally the number of subscriber lines accommodated in one ring signal generator, the average calling rate of each line, and the average hold rate. Although it can be calculated from the time and the call loss rate by the Erlang loss formula, the average call rate, the average hold time, and the call loss rate of each line here are uniquely determined quantities that cannot be changed at the time of circuit design.

Therefore, when the ring signal generator is used in common for a plurality of lines, there is a probability that the ring signal must be sent to the subscribers of the maximum number of simultaneous ring lines, and therefore the ring signal output corresponding to that number. A ring signal generator capable of driving current must be prepared.

In other words, when using a ring signal generator having a certain current driving capability, the maximum number of subscriber lines that can be accommodated cannot exceed the number derived from the Erlang loss equation. there were.

An object of the present invention is to provide a ring signal transmitting circuit which eliminates such drawbacks.

[0009]

SUMMARY OF THE INVENTION A ring signal transmitting circuit of the present invention comprises a subscriber signal conversion circuit group for mutually converting an analog connection signal of a subscriber line and a digital information signal, the digital information signal and PCM. Subscriber signal conversion circuit control unit for mutually converting signals, ring relay contact group for sending ring signals to subscribers, and ring commonly used for a plurality of subscriber lines for supplying ring signals It is characterized by comprising a signal generator and a timing control circuit group for controlling the operation timing of the ring relay contact.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 shows a ring signal transmitting circuit according to an embodiment of the present invention. This ring signal sending circuit includes a subscriber signal conversion circuit (SLIC) group 6 for mutually converting an analog connection signal of a subscriber and a digital information signal, and a subscriber for mutually converting a digital information signal and a PCM signal. A signal conversion circuit control unit 7, a ring relay contact group 8 for sending a ring signal to a subscriber, and a ring signal generator 9 commonly used for a plurality of subscriber lines for supplying a ring signal. , A timing control circuit group 5 for controlling the operation timing of the ring relay contacts.

Next, the operation of this embodiment will be described.

The subscriber signal conversion circuit control unit 2 is a PCM.
When a ring-on request for line n is detected in IN, the contacts assigned to line n of ring relay contact group 3 are operated via timing control circuit 5,
Send a ring signal to. After this arbitrary time, when the subscriber signal conversion circuit control unit 2 detects a ring-off request for the line n in the PCM IN, the ring relay contact 3
Is restored via the timing control circuit 5, and the ring signal transmission to the line n is stopped.

Similarly, according to the ring on / off request for the lines n + 1, n + 2, ..., The corresponding ring relay contact 3 is controlled / operated by the timing control circuit 5 to operate / restore, and the ring signal is sent / stopped. Will be realized.

Considering, for example, a ring signal of 1 second on and 2 seconds off as shown in FIG. 2, in this case, a circuit configuration for inputting three lines of ring relay contact control lines to one timing control circuit 5 To build. As a result, the ring on / off request information for three lines is input to one timing control circuit. In this state, the timing control circuit makes an operation request to each ring relay contact at the timing unique to each line so that the outputs do not overlap at the same time even if the ring-on requests for three lines n, n + 1, n + 2 are input at the same time. Design to do. In other words, in this case, there is an opportunity to ring on / off for each line only once every 3 seconds, and an opportunity to turn on / off each line is once every second. It is given with a shift. Therefore, even if ring ON / OFF requests are simultaneously input from the PCM IN to the three lines n, n + 1, and n + 2, the ring signals actually output to the lines are sequentially output to the lines n, n + 1, and n + 2. Like

[0016]

As described above, the present invention is, for example,
In the case of a ring signal having a cycle of second on / second off, three lines are set as one set to control the timing of ring transmission, so that at least simultaneous output of ring transmission of these three lines does not occur, and a constant current drive is performed. When using a capable ring signal generator, the result is that the maximum number of subscriber lines that can be accommodated can in this case be set to a number three times greater than the number derived from the Erlang loss equation.

[Brief description of drawings]

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

FIG. 2 is a ring transmission timing chart of the ring transmission circuit shown in FIG.

FIG. 3 is a block diagram of a conventional ring signal transmission circuit.

FIG. 4 is a ring transmission timing chart of the ring transmission circuit shown in FIG.

[Explanation of symbols]

 1,6 Subscriber signal conversion circuit (SLIC) group 2,7 Subscriber signal conversion circuit control unit 3,8 Ring relay contact group 4,9 Ring signal generator 5 Timing control circuit group

Claims (2)

[Claims] 1. A subscriber signal conversion circuit group for mutually converting an analog connection signal of a subscriber line and a digital information signal, and a subscriber signal conversion circuit control section for mutually converting the digital information signal and a PCM signal. A ring relay contact group for sending a ring signal to a subscriber, a ring signal generator commonly used for a plurality of subscriber lines for supplying a ring signal, and an operation timing of the ring relay contact. A ring signal transmitting circuit, comprising: a timing control circuit group for controlling. 2. The control circuit of the timing control circuit group controls the timing of the ring signal of each line within the block when the block is handled in units of several lines. The ring signal transmission circuit described.