JPH0533096Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a digital exchange having a testing function for multi-frequency signal receivers.

[Conventional technology]

Conventionally, in space-division switching equipment that handles analog signals, even when connected to the opposite station via a digital transmission line, when it is necessary to add loss to the trunk line in order to maintain a reasonable call quality, this loss is lost at the end. It was given at the station equipment. In a time-division exchange that handles digital signals, if a digital transmission line is used, it is possible to directly interface with the digital transmission line, so no terminal equipment is required. Therefore, it is necessary to insert transmission loss within the station. In addition, since the insertion loss differs depending on the type of connection and the type of opposing station, it is necessary to prepare various insertion losses (for example, 3dB, 5dB, 6dB, etc.). A time-division variable transmission loss insertion device has been proposed.

On the other hand, in time-division switching equipment, the switch part can be made of semiconductor components, making it possible to speed up switching, and connecting and disconnecting by directly controlling the time-division channel network, which is made up of electronic components such as memory gates. , switching, etc. can be performed instantaneously. Therefore, signal control that was conventionally performed outside the communication network, for example, in a trunk, can be performed in the communication network.

Examples of this include changing the transmission level of a tone signal, such as a howler sound, or a multi-frequency signal;
Particularly in the case of howler sounds, it is possible to gradually increase the output level at appropriate timings.

[Problem that the invention attempts to solve]

Conventionally, when transmitting howler sounds, a howler trunk is connected to a telephone whose handset has been forgotten.
The transmission level of the howler sound was gradually increased in the howler trunk over a certain period of time. Therefore, a means for gradually increasing the transmission level is required for each Haulah trunk, and it is impossible to simultaneously send Haulah sound to multiple telephones using one Haulah trunk because the transmission start times are different for each. .

Furthermore, it is necessary for a multi-frequency signal receiver to be able to correctly receive signals only when the signal reception level is within a certain range, and therefore tests are performed by sending signals with different reception levels. In the case of a time-division switch, conventionally, in order to change the reception level of a multi-frequency signal, a multi-frequency signal transmitter is first connected to a test equipment via a time-division channel network, and then the test equipment is connected to a time-division channel network. A test circuit is connected to the multi-frequency signal receiver under test via a network to form a test circuit from the multi-frequency signal transmitter to the multi-frequency signal receiver under test, and the test equipment inserted in the middle is used to eliminate various losses. gave. Therefore, conventionally, a special test device as described above was required.

As mentioned above, conventionally, in order to obtain a tone signal whose transmission level changes, a means for changing the signal transmission level must be provided in the tone signal transmission device (for example, Howler Trunk) or the multifrequency signal receiver test device. There was a problem that I couldn't solve.

The present invention uses the above-mentioned time-division variable transmission loss insertion device to level-adjust the tone signal passing through a time-division communication network, which is equipped with the above-mentioned time-division variable transmission loss insertion device on the highway in the time-division communication path network. It is an object of the present invention to provide a tone signal level control method that eliminates the above problems.

[Means for solving problems]

According to the present invention, a time-division variable transmission loss insertion device is inserted into the highway in a time-division communication network, and the time-division variable transmission loss insertion device is inserted into the signal of each channel input to the insertion device. The input signal to the time-division communication network is configured to be able to selectively send out a signal at the same level as the input signal or a signal at a level obtained by giving a predetermined amount of attenuation to the input signal, respectively, under the control of a common control device. The time-division variable transmission loss insertion device applies various attenuations in stages to the signal sent from the tone signal generator connected to the end and reaches the output end via the communication channel of the time-division communication network. The tone signal generator is configured as a howler sound transmitter with a constant level, and the tone signal generator is configured as a howler sound transmitter with a constant level, and the howler sound signal that reaches the output end of the tone signal generator via the communication channel of the time-division communication network is The feature is that the addresses of various pad information input ROMs read from the pad switch control memory provided in the time-division variable transmission loss insertion device are read out and controlled in stages to reduce the insertion loss in stages and transmit howler sound. The problem is solved by a digital switching system.

〔Example〕

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

FIG. 1 is a connection diagram of an embodiment of the present invention, FIG. 2 is a connection diagram of an example of a time-division variable transmission loss insertion device constructed according to the present invention, and FIG. Connection configuration diagrams of different examples of the configured time-division variable transmission loss insertion device (the diagram is for explaining the principle), Figure 4 is a connection diagram for multi-frequency signal receiver testing, Figure 5 The figure shows a howler tone delivery circuit and its connection to a subscriber telephone.

FIG. 1 shows an example of a time-division channel network. In the figure, IHW ₁ to IHW _n are input highways, TS ₁₁ to _{TS 1n} are primary time switches, SS are spatial switches, and TS ₂₁ to TS _2n is a secondary time switch,
The communication path network shown in FIG. 1 is generally referred to as a T-S-T type communication path network. However, the application of the present invention is not limited to this format. In addition, SPMF ₁ ~
SPMF _n is a primary time switch TS ₁₁ ~
TS _1n call memory, TSM ₁ to TSM _n are time switch control memory, CTR is channel counter,
HSM ₁ to HSM _n are highway control memory,
SPMB ₁ to SPMB _n are each secondary time switches.
TS ₂₁ ~ TS _2n call memory, OHW ₁ ~ OHW _n are output highways, and GHW _a1 ~ GHW _an ,
GHW _b1 ~GHW _bn is intermediate highway, DPS ₁ ~
DPS _n is a time division variable transmission loss insertion device.

The channel counter CTR uses the synchronization clock given to it as the highway IHW ₁ ~ IHW _n , OHW ₁
~OHW It is a cyclic counter that returns the counting output to 0 when counting the number of time slots given to one frame of _n , and the counting output is sent to the primary time switch TS ₁₁ ~TS _1n . Call memory SPMF ₁ ~ Write address of SPMF _n ,
Also, the call memory of secondary time switches TS ₂₁ to TS _2n
Used as the read address for SPMB ₁ to SPMB _n .

In the communication path network shown in Fig. 1, for example, information on time slot ta of incoming highway IHW ₁ is sent to time slot tb of outgoing highway OHW _n , and information on time slot tb of incoming highway IHW _n is sent to outgoing highway OHW n. The case of transmitting to time slot ta of OHW ₁ will be explained.

The time switch control memory TSM ₁ of the primary time switch TS ₁₁ has the same number of addresses as the number of time slots in one frame of the intermediate highway GHW _a1 , and is configured so that it is sequentially accessed in the order of the addresses and its contents are read out. The address data of the communication memory SPMF ₁ is written into each address by a common control device (not shown) of the communication path network.

The call memory SPMF ₁ is accessed by the channel counter CTR in the order of the write addresses, and the input information of the input highway IHW ₁ is written in the order of the addresses, that is, sequentially. In this case, at the time slot ta of the input highway IHW ₁ , the channel counter CTR designates the number of the time slot ta as an address, and the information on the time slot ta is written to the address ta.

In this case, since ta is written as address information by the common control device (not shown) in the area addressed at time slot ti (a≠i) of the time switch control memory TSM ₁ ,
At time slot ti, the address information ta is read out, thereby accessing the address ta of the communication memory SPMF ₁ , and reading out the information written at the address to the intermediate highway GHW _a1 .
In other words, the time slot of input highway IHW ₁
The information on ta is placed on time slot ti of intermediate highway GHW _a1 .

Spatial Switch SS has an entrance intermediate highway.
Highway control memories HSM ₁ to HSM _n are provided corresponding to GHW _a1 to GHW _an , respectively. This memory has the same configuration as the time switch control memory TSM ₁ , but each address has input intermediate highways GHW _a1 to GHW _an and output intermediate highways.
Gates G ₁₁ ~ _{G 1n} connected to GHW _b1 ~ GHW _bn ,
, G _n1 to G _nn are written by a common control device (not shown).

In this case, the time slot ti of the highway control memory HSM ₁ for the incoming intermediate highway GHW _a1
Since information specifying gate G _1n is written in the address read at time slot ti, gate G _1n is specified and conducts at time slot ti.
The information placed on the time slot ti of the incoming intermediate highway GHW _a1 is output to the outgoing intermediate highway GHW _bn at the same time slot ti.

On the other hand, time slot tb of input highway IHW _n
Using the above information as well, you can get to Chuo Highway GHW _b1.
Place it in time slot ti.

Time-division variable transmission loss insertion devices DPS ₁ -DPS _n are connected to the intermediate highways GHW _b1 -GHW _bn , respectively. This time division variable transmission loss device DPS ₁
~DPS _n will be explained in detail later.

Here, the outputs (address data) of the time switch control memories TSM ₁ to TSM _n of the primary time switches TS ₁₁ to _{TS 1n} are also output to the respective secondary time switches.
It is given to the respective call memories SPMB ₁ -SPMB _n as write address data for the call memories SPMB ₁ -SPMB _n of TS ₂₁ -TS _2n . Therefore, the information on the time slot tb of the incoming highway IHW _n is loaded onto the time slot ti of the intermediate highway GHW _b1 as described above and reaches the speech memory SPMB ₁ of the secondary time switch TS ₂₁ . The information ta read from the time switch control memory TSM ₁ at time slot ti is written to the call memory as a write address.
Also given to SPMB ₁ , the above intermediate highway
Address information on time slot ti of GHW _b1
ta, i.e. for sequential read,
Write to the address read at time slot ta.

The information written to the address ta of the communication memory SPMB ₁ is read out by the output information at the time slot ta of the channel counter CTR, and this information is transferred to the time slot ta of the outgoing highway OHW ₁ .
It is output on the

In this way, the information on the time slot tb of the incoming highway IHW _n is output in accordance with the time slot ta of the outgoing highway OHW ₁ . Similarly, the information on the time slot ta of the inbound highway IHW ₁ is outputted in the time slot tb of the outbound highway OHW _n , and the desired exchange connection is established.

Note that MPX ₁ to MPX _n are multiplexers for multiplexing information, and DMPX ₁ to DMPX _n are demultiplexers for separating information, which are provided as necessary.

FIG. 2 is a diagram showing an example of the connection configuration of _the time-division variable transmission loss insertion devices DPS ₁ to DPS _n in FIG. The output is output to Highway GHW ₂ with a certain amount of attenuation.

In the figure, ROM ₀ , ROM ₁ , ROM ₂ , ROM ₃
~ROM _o is read-only memory, SEL is selector, and PSM is pad switch control memory.

The input from the highway GHW ₁ is time division multiplexed digital information with, for example, an 8-bit PCM code placed in each time slot. Read-only memory ROM ₀ , ROM ₁ , ROM ₂ , ROM ₃ ~
Each ROM _o has an address corresponding to the above PCM code, and each address corresponds to an address.
Read-only memory for PCM code
In ROM ₀ , the same PCM code is used, and in read-only memories ROM ₁ , ROM ₂ , ROM ₃ to ROM _o , the level of the signal corresponding to the input PCM code is set to different fixed attenuation amounts d ₁ , d ₂ , d. ₃ , ~d _o
The converted PCM code corresponding to the attenuated signal is stored. For example, if an 8-bit PCM code is input from highway GHW ₁ at time slot ti, each read-only memory ROM ₀ ,
PCM codes equivalent to the above PCM code, d ₁ , d ₂ , d ₃ , ~d _o (dB) from the addresses corresponding to the above PCM codes of ROM ₁ , ROM ₂ , ROM ₃ , ~ROM _o (dB)
Read the attenuated converted PCM code to selector SEL.

Here, the pad switch control memory PSM has the same configuration as the time switch control memory TSM ₁ , and the address read in each time slot contains information regarding the attenuation given to the information in each time slot as a common control (not shown). Written by the device. Now time slot
If information corresponding to the read-only memory ROM _p (p=0 to n) is written in the address read out at time slot ti, this information is read out at time slot ti, and this information is sent to the selector.
When SEL is reached, the output of read-only memory ROM _p is selected and sent to highway GHW ₂ . Therefore, the information input to the highway GHW ₁ according to the time slot ti is attenuated in the read-only memory ROM _p , i.e. 0 in the case of ROM ₀ , otherwise d ₁ , d ₂ , d ₃ ~ Output to highway GHW ₂ after receiving d _o (dB) attenuation. That is,
The highway is controlled by a common control device (not shown).
The information input to GHW ₁ is 0 (no attenuation), d ₁ , d ₂ ,
Attenuation of d ₃ to d _o (dB) can be selectively applied.

FIG. 3 is a connection configuration diagram of a different configuration example of the time-division variable transmission loss insertion device. In the figure, ROM is a read-only memory, with areas A ₀ , A ₁ , A ₂ , ~
Having A _o . Other symbols correspond to those in FIG. 2. In this case, the above area is specified by 3-bit information (n≦7), and the area A ₀ ,
A ₁ , A ₂ to _{A o} each have an address corresponding to, for example, an 8-bit PCM code, similar to the read-only memories ROM ₀ , ROM ₁ , ROM ₂ , ROM ₃ to ROM _o , etc. in FIG. For each address, for the PCM code corresponding to the address, the same PCM code is assigned in area A ₀ , and the same PCM code is assigned to areas A ₁ , A ₂ to A _o
In this case, converted PCM codes attenuated by d ₁ , d ₂ , and d _o (dB) are stored.

Now, in time slot ti, the highway
When attempting to attenuate the information input from GHW ₁ by, for example, d ₂ (dB), the three bits specifying area A ₂ , for example 010, are added to the address read out from the pad switch control memory PSM at time slot ti. Write from the control device.
At time slot ti, the 3-bit information specifying area _A3 read from the pad switch control memory PSM and the 8-bit PCM code from the input intermediate highway GHW ₁ are input as ROM read address information, and the address specified by the above 3 bits is input. The information at the address specified by the received 8-bit PCM code in area A ₂ , that is, the 8-bit converted PCM code that is attenuated by d ₂ (dB) with respect to the input 8-bit PCM code, is the highway GHW _2. is read out. In this way, the read-on memory ROM area is set to the address corresponding to each time slot of the pad switch control memory PSM.
By writing the 3 bits corresponding to A ₀ , A ₁ , A ₂ to _{A o} , a predetermined attenuation (attenuation 0, _{d 1} , d ₂ to d _o ) can be given. That is, the device shown in FIG. 3 has the same function as the device shown in FIG.

This time-division variable transmission loss insertion device can be realized by a read-only memory as shown in FIGS. 2 and 3, but is not limited to this, and can be realized by digital processing that causes a loss in a call. It is also possible to use other means such as using a digital multiplier to multiply the input PCM code by a coefficient that gives a predetermined amount of attenuation and output the result, i.e., a variable digital pad using a digital multiplication method. .

Now, in Fig. 1, if the output of the continuous digital tone generator DTG is applied to an appropriate time slot of the incoming highway IHW _n through the multiplexer MPX _n , such as tb above, and the above exchange is performed, the outgoing highway It can be placed in time slot ta of OHW ₁ . At this time, the continuous tone signal sent from the tone generator DTG is sent via the intermediate highway GHWb ₁ and the time division transmission loss insertion device DSP ₁ having the connection configuration shown in FIGS. 2 and 3. Therefore, the level of the tone signal output to the time slot ta of the outgoing highway OHW ₁ can be controlled by controlling the pad switch control memory (PSM) of the variable transmission loss insertion device DPS ₁ . That is, the attenuation amounts d ₁ , d ₂ , ~d _o, etc. explained in FIGS. 2 and 3 are set in advance to desired values, and the desired value of these is set in the pad switch control memory (PSM). 1
This is done by specifying one.

Next, the case of howler transmission will be explained.

In this case, a howler sending circuit that sends out a constant level of howler (digital tone signal) is used as the digital tone signal generator DTG in Fig. 1, and the howler is inserted in the time-division variable transmission loss insertion devices DPS ₁ to DPS _n . For example, let the loss be d ₁ <d ₂ <~<
Set it so that d _o . Assume that the receiving side of the circuit that should transmit the Howler tone corresponds to the time slot ta of the outgoing highway OHW ₁ . Then, by making the exchange connection as described above, the Howler transmission circuit (DTG) will be connected to the Howler tone transmission circuit (time slot ta of the outgoing highway OHW ₁ ) via the time division variable transmission loss insertion device DPS ₁ . Become. If you want to gradually increase the howler sound, reduce the insertion loss in stages prepared in advance in the common control device (not shown) (the loss inserted by the transmission loss insertion device DPS ₁ )
The above-mentioned howler tone is transmitted by sequentially changing the loss selection information in the pad switch control memory (PSM) under software control according to the switching mode (d _n → ~ → d ₂ , → d ₁ → 0). The level of the signal received by the circuit is gradually increased step by step to achieve the above.

FIG. 5 is a diagram illustrating a howler tone sending circuit and its connection to a subscriber telephone.

To send a howler, first the test access relay TAR of the subscriber circuit LC to which the telephone Tel to which the howler should be sent (in this case the telephone Tel is in an off-hook state) is connected is controlled by the central control (not shown) of the exchange. It is operated by the command (SD) from the device (CC). Contacts tar ¹ to ^{tar 4} of the test access relay TAR are switched, and the test access line TAL of this subscriber circuit LC is connected to the howler tone sending circuit.
Connect to HTS. On the other hand, the digital signal for Hauler output from the digital tone signal generator DTG is connected to the switching network (NW) as described above.
It is connected to the Howler tone transmission circuit HTS via.
This digital signal is sent to the Howler tone sending circuit.
When input to the HTS, it is converted to an analog signal by the DA conversion circuit DA ₂ , and since the Howler tone is higher than the tone level of a normal tone signal, it is sent to an amplifier.
The signal is amplified by about 30 dB in the AMP and sent from the transformer T to the telephone Tel via the test access line TAL of the subscriber circuit LC and contacts tar ² and tar ⁴ .

The A relay of the howler tone transmission circuit HTS monitors the on-hook/off-hook state of the subscriber's telephone Tel, and its contact a allows the subscriber's circuit to be
Notifies the LC of the on-hook/off-hook status of the telephone that is sending howlers. i.e. telephone Tel
However, when it is off-hook, the A relay operates and closes its contact a, and when it is on-hook, the A relay is restored and its contact a is opened. In the subscriber circuit LC,
The operation of the A relay of the Howratone sending circuit HTS is monitored by the AS relay according to the open/closed state of its contact a.
The status is communicated to the central control unit (CC) via the SCAN line.
to communicate.

When the subscriber who was sending the howler notices that he has taken the phone off the hook due to the howler and picks up the phone, the A relay is restored, contact a opens, and the AS relay of the subscriber circuit LC is restored, so the central control unit (CC) Based on the status of the monitored SCAN line, it knows if the telephone is on-hook and stops sending howlers.

In the subscriber circuit LC, HYB is a 2-wire/4-wire conversion circuit, AD ₁ is an AD conversion circuit, and DA ₁ is a DA conversion circuit.

In addition, as mentioned above, the multi-frequency signal receiver (PB
signal and MF signal) accurately receives only input multifrequency signals whose levels are within a certain range,
You need to be able to analyze that information. Automatic testing of the reception level sensitivity of receivers connected to an exchange has conventionally been carried out using a time-division channel network TD-SW (in this case, a conventional method without a time-division variable transmission loss insertion device), as shown in Fig. 4. For example, the time-division variable transmission loss insertion device DSP ₁ ~
DSP _n is removed), the multi-frequency signal transmitter MF-S and the multi-frequency signal receiver MF-R are
The multi-frequency signal generated by the transmitter MF-S is attenuated by the test circuit TST, and the multi-frequency signal at an appropriate level is This was done by inputting the test signal to the receiver MF-R. The symbols in FIG. 4 correspond to those in FIG. 1.

According to the present invention, in FIG. 4, a time-division channel network TD-SW having time-division variable transmission loss insertion devices DPS ₁ to DPS _n as shown in FIG. Directly connect the transmitter MF-S and receiver MF-R using a time division communication path,
Time-division variable transmission loss insertion device in the communication path
Tests are performed by controlling DPS _n by a common control device (not shown) and inputting test signals of various levels to the receiver MF-R. This eliminates the need for the test circuit TST. Then, it is sufficient to set only one communication path.

According to the present invention, in addition to the above, a common control device (not shown) controls the tone signal sent from one continuous digital tone signal generator to give various fixed attenuations at fixed timings. This makes it possible to create and send out various new signal tones.

[Effect of idea]

As described above, according to the present invention, a tone signal of a constant level sent from the input end of a time-division channel network can be extracted from the output end after being subjected to various attenuations, and in this case, the level of the tone signal can be Control can be performed in the communication network, and there is an effect that it is not necessary to provide individual level adjustment sections in each signal sending circuit (howler sending circuit, etc.) to obtain signals of various levels.

In the case of howler transmission, there is no need for a level adjustment section in the howler transmission circuit, and it is possible to simultaneously send gradually increasing howler sounds with different transmission start times from one howler transmission circuit at a constant level to multiple telephones. In the case of testing multi-frequency signal receivers, there is no need for a test circuit to adjust the signal level, making it more economical to test various attenuations at various timings using a single existing tone signal source. By providing a variety of different new modes of yet soft tones, this is advantageous when new tones are required for new services. Another advantage is that the time-division variable transmission loss insertion device provided for good transmission of audio signals can be used efficiently.

[Brief explanation of the drawing]

FIG. 1 is a connection diagram of an embodiment of the present invention, FIG. 2 is a block diagram of an example of a time-division variable transmission loss insertion device constructed by the present invention that can be used in the above embodiment, and FIG. Similarly, FIG. 4 is a block diagram of a different example of the time-division variable transmission loss insertion device. FIG. 4 is a block diagram of an example in which the present invention is applied to a test of a multi-frequency signal receiver. FIG. FIG. 3 shows a connection to a subscriber telephone; IHW ₁ ~IHW _n ...Inbound highway, TS ₁₁ ~ _{TS 1n}
...Primary time switch, GHW _a1 ~ GHW _an ,
GHW _b1 ~GHW _bn ...Intermediate highway, SS...
Spatial switch, DPS, DPS ₁ to _{DPS n} ... Time division variable transmission loss insertion device, TS ₂₁ to _{TS 2n} ... Secondary time switch, OHW ₁ to OHW _n ... Exit highway,
SPMF ₁ ~ SPMF _n , SPMB ₁ ~ SPMB _n ... Call memory, TSM ₁ ~ TSM _n ... Time switch control memory, G ₁₁ ~ G _1n , ~, G _n1 ~ G _nn ... Gate,
HSM ₁ ~HSM _n ...Highway control memory,
MPX ₁ ~ MPX _n ...Multiplexer, DMPX ₁ ~
DMPX _n ...Demultiplexer, DTG...Digital tone signal generator, CTR...Channel counter, GHW ₁ , GHW ₂ ...Highway,
ROM, ROM ₀ , ROM ₁ , ROM ₂ , ROM ₃ , ~,
ROM _o ...Read-only memory, SEL...Selector, PSM...Pass switch control memory, A ₀ ,
A ₁ , A ₂ ~ A _o ... Read-only memory ROM area, TD-SW ... Time division communication network, MF-S ...
Multi-frequency transmitter, MF-R...Multi-frequency receiver, TST
...Test circuit,,,...Time division communication path.

Claims (1)

[Claim for Utility Model Registration] A time-division variable transmission loss insertion device is inserted into a highway in a time-division communication network, and the time-division variable transmission loss insertion device is common to signals of each channel input to the insertion device. It is configured to be able to selectively send a signal at the same level as the input signal or a signal at a level obtained by giving a predetermined amount of attenuation to the input signal under the control of a control device, and is connected to the input end of the time division telephone network. The time-division variable transmission loss insertion device controls the time-division variable transmission loss insertion device to apply various attenuations in stages to the signal transmitted from the tone signal generator and reaching the output end through the communication channel of the time-division communication network. The tone signal generator is configured as a howler sound transmitter with a constant level, and the time-division variable transmission is applied to the howler sound signal that reaches the output end of the tone signal generator via the communication channel of the time-division call. Various pad information input read from the pad switch control memory provided in the loss insertion device
Controls reading of ROM addresses in stages,
A digital switching device characterized by reducing insertion loss in stages and transmitting howler sound.