JPS60165157A - Automatic private branch exchange - Google Patents

Abstract

PURPOSE:To ensure always >1 idle private line by transmitting a long telephone warning tone to a long call talker when a private line connected to a private branch of automatic exchange is busy so as to cut off forcibly the line after a prescribed time. CONSTITUTION:Private line trunks TLT0-TLTn and a tone trunk TOT for warning sound transmission are provided. The private line trunk busy storage circuit 1 stores the busy and idle state of the TLT0-TLTn so as to store a talking time of a busy trunk to a private line trunk talking time storage circuit 2. A central controller CC supervises whether or not the TLT0-TLTn are busy by using the storage circuit 1. When all the trunks are busy, the CC identifies a trunk having the longest talking time among talking times stored in the storage circuit 2 and a private line trunk corresponding extension number storage circuit 4 reads an extension number in talking with the said trunk. Then a line circuit LC of the said extension number and the tone trunk TOT are connected so as to transmit a long telephone call warning tone to the talker. Furthermore, when the call surpasses the time of a forced cut-off time storage circuit 3, a restoration signal is transmitted so as to cut off the talking.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic private branch exchange system which has a dedicated line trunk and a tone trunk and is connected to other equipment through the dedicated line, and more specifically, an automatic private branch exchange system that has a dedicated line trunk and a tone trunk and is connected to other devices through the dedicated line. The present invention relates to an automatic private branch exchange device that takes into consideration securing an empty dedicated line when the dedicated line is busy.

In conventional automatic private branch exchanges of this type, if all leased line trunks are busy, a new call cannot be connected until at least one leased line trunk becomes free. Therefore, if the dedicated line is monopolized by long-distance callers, there is a drawback that the dedicated line cannot be used efficiently.

An object of the present invention is to eliminate the above-mentioned disadvantages, and to provide a long-distance service to long-distance callers when all leased lines connected to an automatic private branch exchange are busy or when more than a certain number of leased lines are busy. To provide an automatic private branch exchange device capable of securing at least one vacant dedicated line regardless of the usage status of the dedicated line by sending out a telephone caller and forcibly disconnecting 2 after a certain period of time.

To achieve the above object, an automatic private branch exchange device according to the present invention has a leased line trunk and a tone trunk, and stores the usage status of the leased line trunk in the automatic private branch exchange device connected to other devices by the leased line. A leased line trunk busy memory circuit, a leased line trunk talk time memory circuit that stores the talk time of the busy leased line trunk, a forced disconnection time memory circuit that stores a predetermined time, and a busy extension line. A leased line trunk compatible extension number storage circuit for storing numbers is provided, and the memory contents of the leased line trunk busy memory circuit are referred to when all leased lines are busy or when more than a certain number of leased lines are busy. The call time of the busy leased line trunk is read from the leased line trunk talk time storage circuit, and by comparing them, a leased line that meets a predetermined condition is identified, and the leased line trunk compatible extension number storage circuit reads the The identified extension subscriber using the leased line is identified, and an alarm sound is sent from the tone trunk to the extension subscriber or the other subscriber, and for a predetermined time period stored in the forced disconnection time storage circuit. If the identified leased line is not freed even after a period of time has elapsed, a restoration signal is sent to the leased line trunk.

According to the above configuration, exclusive use of the leased line by a specific person can be prevented, so that the leased line can be used efficiently, and the object of the present invention can be completely achieved. - Hereinafter, the present invention will be explained in more detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an automatic private branch exchange apparatus according to the present invention.

In the figure, FiXo, EXI -EXn, EXn
+i to EXn+m are m+n extension subscribers, and have corresponding line circuits LOo and LOl-LOn, respectively.

It is accommodated in L On+l-L On+m. For these n+m extension subscribers, n dedicated line trunks T
L T o * T L T 1 to T L Tn are provided, and a tone trunk TOT for sending out an alarm sound is further provided. The leased line trunk busy memory circuit 1, the leased line trunk talk time memory circuit 2, the forced disconnection time memory circuit 3, and the leased line trunk corresponding extension number memory circuit 4 are connected to a central control unit Co that controls exchange control. . The leased line trunk busy memory circuit is a circuit that stores the usage status (empty or busy) of each leased line trunk (TLT).

The leased line trunk talk time storage circuit 2 stores the leased line trunk (
This is a circuit that accumulates call time for each call time (TLT), and the call time is updated at regular intervals by the central control unit Co. - The contents stored in the leased line trunk call time storage circuit 2 are reset to 0 by the central controller OO when the call ends.

The forced disconnection time storage circuit 3 is a circuit that stores the time from when the long call warning sound is sent until the call is disconnected.

The leased line trunk compatible extension number storage circuit 4 is a circuit in which the leased line trunk (TLT) and the extension number in use are stored for each leased line trunk.

FIG. 3 is a flowchart illustrating the operation of the automatic private branch exchange system according to the present invention.

The main operating procedures will be explained below according to this flowchart.

As mentioned above, each leased line trunk I'LTo-TL is stored in the leased line trunk busy storage circuit 1 by the central controller CC.
The state of whether Tn is busy or empty is memorized, and the talk time of the busy leased line trunk is stored in the leased line trunk talk time storage circuit 2.
It will be stored in the memory. The central control unit 00 reads the contents of the leased line trunk busy memory circuit 1 at regular intervals and monitors whether all leased line trunks TLTo to TLTn are busy (FIG. 2(a)).

When all the leased line trunks TLTo to T L Tn are busy, each call time is read out from the leased line trunk talk time storage circuit 2, and compared, the leased line trunk with the longest talk time is identified (the Figure 2(b)). On the other hand, if all leased line trunks TLTO to TLTn are not busy, the process proceeds to the next step. When the longest leased line trunk of the call is identified, the central control unit OC then reads out the identified leased line trunk and the extension number in progress from the leased line trunk corresponding extension number storage circuit 4 (Fig. 2). (C)).

The central controller CC reads out the line circuit L of the extension number.
In order to connect the tone trunk TOT with the tone trunk TOT, the switch SW is closed for a very short period of time,
The OT sends out a long call warning sound to the caller (see Figure 2).
d)).

Thereafter, the central control unit CC monitors the termination of the call on the leased line trunk, and if the call is in progress for longer than the time read out from the forced disconnection time memory circuit, it sends a recovery signal to the leased line trunk; If the call ends within the time limit, the process moves to the next step (FIG. 2(f)).

When the restoration signal is sent to the dedicated line trunk, the connection between the extension subscriber who is currently talking and the dedicated line trunk is released at the same time, and the call is disconnected (FIG. 2 (g)). As a result, when the dedicated line trunk becomes empty, it can be connected to by other extension subscribers.

Although one embodiment has been described above, various other embodiments are possible.

For example, in this embodiment, when the leased line is in full use, the contents of the leased line trunk talk time storage circuit are read out.
However, the contents of the leased line trunk talk time storage circuit may be read out when the leased line is busy more than a certain number of times.

Also, although the leased line trunk with the longest talk time is identified, a leased line trunk with a talk time longer than a certain length or a fixed number of leased line trunks with a longer call time is also acceptable.

Furthermore, although the switch is closed between the line circuit of the extension number and the tone trunk for a very short period of time or one hour, it is also possible to close the switch between the leased line trunk and the tone trunk. .

It is also possible to configure each storage circuit with a storage area of a main storage device (not shown).

As explained above in detail, according to the present invention, if all leased lines are busy or more than a certain number of leased lines are busy, a long call alarm is sent to the long caller, and the caller is forcibly disconnected after a certain period of time. This has the effect of preventing long-distance callers from monopolizing the dedicated line.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an automatic private branch exchange apparatus according to the present invention, and FIG. 2 shows the apparatus shown in FIG. 1. 1 is a flowchart for explaining the operation of FIG. 1... Dedicated line trunk busy memory circuit 2... Dedicated line trunk talk time memory circuit 3... Forced disconnection time memory circuit 4... Dedicated line trunk compatible extension number memory circuit BXo
, EXt-EXn, EXn+t-FiXn+m...
Extension subscribers LOo, LO1~LOn, LOn+t-LOn+m
... Line circuit TLTo, T LTr ~ TLTn ... Dedicated line trunk TOT ... Tone trunk CC ... Central control unit SW ... Switch Patent applicant NEC Corporation Representative Patent attorney Hisashi Inoro Figure 1 Figure 2

Claims (1)

[Claims] In an automatic private branch exchange device having a leased line trunk and a tone trunk and connected to other devices by a leased line, a leased line trunk busy memory circuit for storing the usage status of the leased line trunk, and a leased line trunk busy memory circuit for storing the usage status of the leased line trunk, and a leased line trunk busy storage circuit for storing the usage status of the leased line trunk, A leased line trunk talk time memory circuit for storing trunk talk time, a forced disconnection time memory circuit for storing a predetermined time, and a leased line trunk compatible extension number memory circuit for storing a busy extension number, Referring to the memory contents of the leased line trunk busy memory circuit, if all leased lines are busy or more than a certain number of leased lines are busy, the leased line trunk talk time memory circuit stores the information of the busy leased line trunk. By reading out the call time and comparing them, a leased line that satisfies a predetermined condition is identified, and the identified extension subscriber using the leased line is identified by the leased line trunk compatible extension number storage circuit, and the extension subscriber using the identified leased line is identified. Sending an alarm sound from the tone trunk to the subscriber or the other subscriber, and when the identified leased line is not empty even after the predetermined time stored in the forced disconnection time storage circuit has elapsed; , an automatic private branch exchange device configured to send a recovery signal to the leased line trunk.