JPS6021508B2 - Communication path test method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for testing a communication path, and more particularly to a method for testing a communication path established between a calling subscriber and an outgoing trunk of a time-division exchange on a call-by-call basis.

In the space division switching ≠ sword machine, the communication path is constructed of mechanical contacts, and a metallic line that can pass direct current as a communication path is constructed between the line circuit and the trunk, so that the subscriber's telephone is off-hook. In this state, a loop monitoring relay provided in the trunk is operated by the direct current flowing through the communication path of the terminal talic line, thereby confirming continuity between the trunk and the communication path of the subscriber's telephone institution for each call.

In other words, in the case of space division switching ≠ missed machine, it is sufficient to test the continuity of one DC circuit passing through the subscriber telephone, and therefore, depending on the operation of the loop monitoring relay installed in the trunk, the communication path It is easy to detect whether or not it has been configured. Furthermore, since the space division exchange that accommodates subscriber telephones is generally a two-wire exchange, testing of one communication path (DC circuit) was sufficient. However, in a time-division switch, the communication path device consists of a memory and a gate, and the communication path is a digital circuit that does not pass direct current, so it is impossible to test the communication path using direct current as in a space-division switch.

Furthermore, since the time-division switch performs four-wire switching, there are two communication paths with different signal transmission directions for one communication connection, and therefore it is necessary to conduct tests in consideration of the signal transmission direction. In addition, conducting a test by circulating a test number on a call path while both the calling and called subscriber telephones are off-hook may cause interference with the call. Undesirable.

As mentioned above, there are various problems in performing a channel test for each call in a time-division switching system.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a method for testing a communication path including an encoder and a decoder between a calling subscriber and an outgoing trunk, which is suitable for a time division switch. The purpose of this is, according to the invention, to make a time-shared exchange call with the called party in order to branch the signal from the outbound highway to the called party and the incoming highway from the called party, in the event that time-shared exchange ≠ chance. a branch circuit provided between the calling party and the time-division switching channel, and return switch means provided corresponding to each subscriber and returning the sending and receiving sides of the same subscriber between the calling party and the time-division switching communication path; and a circuit that detects a ringback tone signal from a signal branched from the incoming highway from the called party side in the branch circuit, and a circuit that detects a ringback tone signal from the signal branched from the incoming highway from the called party side and the called party of the branch circuit. a communication path testing device having a matching circuit with a signal branched from an outgoing highway to the called party side, and detects a ringback tone signal from a signal branched from an inbound highway from the called party side. During the call period after detection in the circuit, on the one hand, the back tone signal branched from the incoming highway of o from the called party side is guided directly from the branch circuit to the above-mentioned verification circuit, and on the other hand, the above-mentioned branch circuit The signal is guided from the time-division switching communication network to the callback switch means, the outbound highway to the called party, and the branch circuit to the verification circuit, and is verified by the verification circuit.

The following embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention. In the figure, B is the calling subscriber's telephone, LC is the 0 line circuit, 1 is the high-precision circuit for 2-to-4 line conversion, COD is the encoder, DEC is the decoder, HSW is the time division switching channel, and D
/1 is a branch circuit, OGT is an outgoing trunk, SPC is a communication path control device, SX, SY are signal return switch means, S
PTE is a communication path testing device, DET is its ringback tone signal detection circuit, and DCC is its digital verification circuit. Now, assume that subscriber telephone B makes a call.

A connection to the called party is established in a known manner by dialing digits from telephone B. This connection is made from the calling telephone B to its line circuit LC, //bibbit circuit, encoder COD, decoder DEC, time division switching channel HSW, branch circuit D/1, outgoing trunk OGT, outgoing highway HW, and It reaches the other party's office via an outgoing trunk line with an incoming highway HW2, and further extends to the called telephone. If the called telephone is free, a ringing signal is sent from the other party's station to it, and a ring back tone signal is sent to the calling subscriber via the trunk line, and if the called party answers, the call is possible. Become. The call signal sent from the calling subscriber's telephone B passes through the telephone B and the line circuit LC and reaches the hybrid circuit, from which it is sent to the encoder OD and time-division switching telephone line H.
SW, branch circuit D/1, outgoing trunk OGT, outgoing highway HW. It reaches the other subscriber via the outgoing route via
Call signals from the other subscriber are sent to the incoming highway HW2, outgoing trunk OGT, branch circuit D/1, and time-sharing switching path HS.
W, through the incoming call path via the decoder DEC, reaches the high-precision circuit, and then through the line circuit LC to the telephone B.
reach.

In the present invention, when both the calling and called telephones are connected and are not yet in a talking state, that is, during the ringback tone signal transmission period, that is, during the called telephone ringing period, the calling telephone B is contacted. , the above outgoing and incoming call paths between the outgoing trunk OGT and the hybrid date are tested simultaneously. In this embodiment, a ringback tone signal is used as a test signal when testing the communication path described above. When the calling telephone B is connected to the called telephone, a ringback tone signal is sent from the incoming highway HW2 as described above.

The communication path control device SPC controls the branch circuit D/1 to branch this signal also to the test line TL. This is led to the ringback tone signal detection circuit DET, and when this circuit detects it, it notifies the communication path control device SPC of the detection, and upon receiving this signal, the communication path control device SPC controls the switch means SX. Make this conductive. This switch means SX can be constituted by a relay, for example. The ringback tone signal branched to the test line TL is also input to a collation circuit DCC configured as a digital collation circuit. On the other hand, the ringback tone signal that is not branched at the branch circuit D/1 is sent to the time division switch HSW.
, reaches the hybrid circuit via the said incoming path via the decoder DEC, but without entering the hybrid circuit, passes through the switch means SX in the conductive state and passes through the encoder COD and the time division The branch circuit D/1 is reached via the above-mentioned outgoing route which reaches the outgoing highway HW via the exchange HSW.

Under the control of the speech path control device SPC, the above signal is dropped from the output highway HW to the test line TL2 in the branch/add switching circuit D/1, and is input to the above collation circuit DCC.

The collation circuit DCC collates the inputs from the test lines TL and TL2, and if they match, the matching information is sent to the call bribe control device SPC.

The communication path control device SPC determines that the communication path is correctly configured, restores the switching means SX, and controls the signal so as not to return the signal. If the called party answers, the call becomes possible. If they do not match, send mismatch information.

The call bribe control unit SPC determines that the call path is not configured correctly and takes appropriate action. For example, switch means SY
The signal is looped back, and in this state, a test for a communication path in which the encoder does not include OD and decoder DEC is performed in the same manner as above. At this time, if the matching circuit DCC detects a match, it is determined that there is a failure in the encoder COD or decoder DEC. If a mismatch is detected, it is determined that there is a failure in the time division switched communication path HSW. Furthermore, when it is determined that the above disorder occurs,
It is also possible to retry the connection. FIG. 2 is a block diagram of a different embodiment of the invention. In the figure, the symbols are the same as in FIG. 1, and 0 and D/1 are branch and insertion switching circuits, and DOSC is a digital test code generator.

In this embodiment, a test signal generated from the test signal generator AKINE C is transmitted to and from the input and output lines when the ringback tone signal is stopped, and a communication path test is performed. In FIG. 2, when calling subscriber telephone B is connected to the calling telephone as in FIG. 1, and a ringback tone signal is returned from the other party, the call path control Under the control of the SPC, the ringback tone signal is branched from the branching and insertion switching circuit D/1 to the detection line DL, and detected by the IJ ringback tone signal detection circuit DET. When it is detected that the first IJ back tone signal has disappeared and the pause period has started, this information is sent to the communication path control device SPC, and the communication path control device SPC 1, and the test equipment from the test signal generator DOSC is connected to the test line TL.
The test signal is inserted into the incoming highway HW2 via the outgoing highway HW2, and the test signal that has passed through the incoming and outgoing communication path from the outgoing highway HW is branched to the test line TL. 0 Therefore, if the incoming and outgoing communication paths are configured correctly, the test signal sent from the test signal generator DOSC will be transmitted from the test line TL2, the branch and insertion switching circuit D/1 to the time division switched communication path HSW and The incoming call goes through the decoder DEC, then the switching means SX in the conductive state as in the example of FIG. Then, it reaches the insertion switching circuit ○/1, where it branches to the test line TL and inputs it to the digital verification circuit DCC.

On the other hand, the test signal is branched from the output of the test signal generator U$C and is also directly input to the collation circuit DCC. Therefore, by detecting coincidence of the two inputs with the collation circuit DCC, the communication path test is carried out in exactly the same manner as in the embodiment of FIG. 1.
As described above, the present invention provides time-division switching; in an unlucky occasion, a communication path including an encoder and a decoder configured between a calling subscriber's telephone and an outgoing trunk is connected for each call, and a ringback tone signal is There is an advantage that the test can be carried out without any disturbance to the call during the transmission period, that is, while the called telephone is ringing.

In the embodiment shown in FIG. 1, the ringback tone signal sent from the other station is used as the test signal, so there is no need for a test signal generator, which has the advantage of simplifying and economical installation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the invention, and FIG. 2 is a block diagram of another embodiment of the invention. B: Calling subscriber's telephone, LC: Its line circuit, H: Hybrid circuit for 2-wire to 4-wire conversion, COD: Encoder, DEC: ...Decoder, HSW ...Time division switched communication path, D/1.
...branch circuit, or branch and insertion switching circuit, OGT...outgoing trunk, SPC...
Communication path control device, SX, SY... switch means for signal return, SPTE... communication path testing device, DET... ringback tone signal detection circuit, DCC... ...Same as digital verification circuit, DOSC...Digital test signal generator. Oh figure juice 2 figure

Claims (1)

[Claims] 1. In a time-division switching system, a signal is provided between the called party and the time-division switched communication path in order to branch signals from the outgoing highway of the called party and the incoming highway from the called party. a branch circuit provided, a turn-back switch means provided corresponding to each subscriber and for returning the sending side and the receiving side of the same subscriber between the calling party side and the time-division switched communication path; and the above-mentioned branch circuit. A circuit for detecting a ringback tone signal from a signal branched from an incoming highway from the called party side, and a signal branched from the incoming highway from the called party side and an outgoing highway to the called party side of the branch circuit. and a communication path testing device having a circuit for checking the branched signal, and the ringback tone signal is detected by the ringback tone signal detection circuit from the signal branched from the incoming highway from the called party side. During the telephone ring period,
On the one hand, the ringback tone signal branched from the incoming highway from the called party is guided directly from the branch circuit to the matching circuit, and on the other hand, from the branch circuit, the ring back tone signal is transmitted from the time-division switched communication path network to the callback switch means and from the called party's side. A communication route testing method characterized in that the signal is led to the collation circuit via an outbound highway and the branch circuit, and is collated in the collation circuit. 2. In the time division switch, the signal is branched from the outgoing highway to the called party side and the incoming highway from the called party side,
In addition, there is a branch and insertion switching circuit provided between the called party and the time-division switched communication path in order to insert a signal into the incoming highway from the called party, and a branch and insertion switching circuit provided corresponding to each subscriber. and a return switch means for looping back the sending and receiving sides of the same subscriber between the calling party and the time-division switched communication path, and a signal branched from the incoming highway from the called party in the branching and insertion switching circuit. a circuit for detecting a ringback tone signal, a digital test signal generator, and a verification circuit; During the ringback tone signal pause during the ringing period of the called telephone after being detected by the backtone signal detection circuit, the test signal from the digital test signal generator is transmitted to the called telephone by the branch and insertion switching circuit. The digital test signal is inserted into the incoming highway from the side and guided from the time-division switched communication path network to the above-mentioned return switch means, the outgoing highway to the called party side, and the above-mentioned branching and insertion switching circuit to the verification circuit. A communication path testing method characterized in that a test signal from a generator is directly guided to the collation circuit and collated in the collation circuit.