JPS5842678B2 - Early dial detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to early dial detection schemes, and more particularly to early dial detection schemes in trunk trunks of store program controlled switches.

In a connection between stations in a toll-dial telephone network, after the originating station activates the terminating station, a activation completion signal indicating when the terminating station will be able to receive the selection signal is sent back to the originating station, and then the originating station Selecting dialed digits is desirable to achieve reliable interoffice connectivity.

This requires the calling station to store and resend the dialed digits sent by the caller.

However, depending on the type or size of the originating station, the function of storing and retransmitting dialed digits may not be provided, and after receiving the trunk line route selection digits, the terminating station may be ready to receive dialed digits after selecting and capturing the trunk line for that route. At this point, a second dial tone is sent back, and after hearing it, the caller dials the subsequent digits, and the dialed digits are directly received at the destination station.

At this time, the caller does not necessarily dial after hearing the second dial tone, and in some cases dials subsequent digits consecutively after the trunk line route selection digit.

In this case, part of the dialed digits to be received by the terminating station may be sent before the terminating station is ready to receive the dialed digits, making it impossible to receive them.

It is clear that if the receiving station performs an exchange operation based on incompletely received digits that are different from the dialed digits of the caller, erroneous connections will occur.

Therefore, it is essential for the receiving station to detect the premature dialing.

Conventionally, an early dial detection means that was difficult to use was provided after the incoming call activation was detected.

An example of a trunk trunk equipped with this type of early dial detection means will be explained below with reference to FIG.

In FIG. 1, the ground is connected to the terminal RG of the trunk trunk as an incoming call activation signal from the originating station, and relay R is operated, and then relay B is operated.

Since the terminals 5No and R are brought into a conductive state by the contact r, the call processing program of the terminating exchange detects this state via the scanning device SCN and connects the terminals AI 7 Bl of the trunk trunk.
Close the network to connect the outgoing register trunk.

A second dial tone from the originating register trunk is transmitted back to the originating station via the network and trunk trunk.

After hearing the second dial tone, when the caller dials the connection number, the air applied to the terminal RG of the trunk line is intermittent in response to the dial pulse, so the relay R repeats the recovery operation, and the contact r connects the calling register trunk. The dial pulse sent by the caller is relayed to the calling register trunk.

When relay R is restored for the first time, relay C operates and holds the dial pulse while receiving it, and disconnects and terminates the trunk line side communication line from the dial pulse relay loop circuit.

When reception of the dialed digits is completed and the called party answers the call, the called party is connected to terminals A22 and B2 of the trunk trunk through the network, relay A of the trunk is activated, and terminals SN1 to R are connected by contact a. The call processing program then monitors the call status of the called party via the scanning device SCN.

1 or more indicates that the dialed digits have been received normally, but if the dialing pulse arrives at the receiving station after the call processing program detects the incoming call state and before the connection with the calling register trunk is completed, relay R
As a result of the recovery action, the continuity between terminals 5No and R is interrupted, and the call processing program, which monitors via the scanning device SCN until the connection with the originating register trunk is completed, detects the discontinuity and treats it as early dialing. The trunk trunk is then connected to the busy tone trunk through the network, and a busy tone is sent to the calling party to notify the caller of the unsuccessful connection.

As is clear from the above description, measures are taken for early dialing that occurs after incoming call activation is detected, but conventional measures are not effective for early dialing that occurs before incoming call activation is detected.

An object of the present invention is to make it possible to detect early dialing that occurs before activation of incoming calls on trunk trunks is detected, and to completely eliminate erroneous connections caused by early dialing.

This object is achieved by providing a means for monitoring the operating state of the relay which is kept in operation during the reception of the digital pulse at the same time as the activation of the incoming call is detected in the trunk line trunk.

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

FIG. 2 is a circuit example of a trunk trunk which is an improved version of the conventional trunk trunk shown in FIG. 1 by implementing the present invention. It is an explanatory diagram.

The difference in FIG. 2 from FIG. 1 is that a contact C of a diamond pulse holding relay C is inserted between terminals SN1 to R in parallel with contact a.

In FIG. 2, when there is a normal connection without early dialing, the same operation as the conventional trunk trunk shown in FIG. 1 is performed.

Next, if early dialing arrives immediately after a call arrives but before the call processing program detects the call, relay C operates when relay R is first restored, and contact C connects terminal SN.
A conductive state is established between 1 and R.

The call processing program is connected via the scanning device SCN to terminal 5No.
-R, and at the same time detects the activation of an incoming call by closing contact r, checks the continuity between terminals SN1 and R. If continuity is detected, it is assumed that early dialing has arrived, and the trunk trunk is connected to the network. to the busy tone trunk via the caller, and sends a busy tone to the caller to notify the caller of the unsuccessful connection.

Since the relay C is a slow recovery relay that is held during the dial pulse, even if early dialing is completed at the time of activation detection, the above-mentioned early dialing detection can be carried out satisfactorily.

(Figure 3) Note that terminals SN1 to R remain electrically conductive during normal connection, while receiving subsequent dialed digits, and even after the called party responds; however, in the call processing program, each connection processing process is handled separately. .

As is clear from the above description, according to the trunk line shown in FIG. 2, early dialing can be detected immediately after a call arrives, and the possibility of erroneous connection is further reduced compared to the conventional method.

It should be noted that FIG. 2 is merely an embodiment of the present invention, and the trunk trunk circuit may have many different signal formats or functions, but the effects of the present invention remain the same.

As described above, according to the present invention, it is possible to detect early dialing that occurs before the incoming call activation of the trunk trunk is detected by providing a means for monitoring the operating state of the relay that maintains operation during dial pulse reception at the same time as the activation of the incoming call is detected in the trunk trunk. This eliminates any misconnections caused by early dialing.

[Brief explanation of drawings]

Figure 1 is an example of a trunk line trunk circuit diagram according to the prior art;
The figure shows an example of a trunk line circuit diagram according to an embodiment of the present invention.
FIG. 3 is a diagram for explaining the operation of the trunk trunk shown in FIG. In the figure, R, B, C, A...Relay.

Claims (1)

[Claims] 1. An early dial detection method, which is characterized in that, in a trunk trunk of a storage program controlled exchange, means is provided for monitoring the operating state of a relay that maintains operation during reception of dial pulses at the same time as incoming call activation is detected.