JPH0412080B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixed connection signal processing system that does not require special circuits or switching of signal paths when establishing a fixed connection in a time division exchange.

A fixed connection is when a subscriber A accommodated in a certain station A fixed connection between subscriber A and a trunk line.

If such a fixed connection is established, subscriber A in the above example is physically housed in station This is a local call and has the advantage of lower telephone charges if there are many calls to the Y station area.

FIG. 1 conceptually explains a fixed connection in a time division switch. Subscriber A is connected to the time division network (hereinafter referred to as TD-NW) 2 of the X station through a subscriber circuit (hereinafter referred to as LC) 1, but is not controlled by the CC3 of the X station and is connected to the digital It is controlled by CC 7 of station Y, which is connected via terminals (hereinafter referred to as DT) 4 and 5 and a digital trunk line 6. On this occasion,
Control signals between subscriber A and station Y, that is, ringing signals, off-hook and on-hook signals, are transmitted and received through the TD-NW of station X.

This control method for fixed connections is
In the case of a time division switch exchanged by TD-NW,
This is especially necessary. FIG. 2 illustrates fixed connections in a space division switch. In the case of a space-division switch, a space-division network (SD-
As a digital terminal connecting NW) 11 and digital trunk line 12, a channel bank 13, which is a carrier terminal station having an analog-digital interchange function (A-D), is provided. Therefore, since each channel can be divided by the channel bank 13, there is no need to pass both the call signal and the control signal through the network. On the other hand, in the case of a time-division switch, the analog-to-digital switching function is included in the LC, so it is desirable to split the channel through the LC, and therefore the control signals must pass through the network. A method is needed.

Conventionally, as a fixed connection signal processing method in a time division switch, a method has been used in which the number of bits per channel in the TD-NW is increased and a fixed connection signal is placed on the increased bits.

FIG. 3 conceptually shows a conventional fixed connection signal processing system. The audio signal and fixed connection control signal between LC1 and DT4 are TD-NW2
are sent and received via the same channel. The control signal for the fixed connection consists of a ringing signal and off-hook and on-hook signals as described above. Note that the LC 1 has a ringing signal generator (hereinafter referred to as RG) 21, and has a function of sending out a ringing signal to the subscriber in response to a ringing signal.

FIG. 4 shows the channel bit configuration within the TD-NW in the conventional system. In the figure, a indicates the bit configuration when no fixed connection is made, and consists of 8 bits of audio. b shows the bit configuration for fixed connection, which consists of 8 bits of audio and 1 bit of control signal for fixed connection. For 1 bit of the control signal, "1" indicates off-hook and "0" indicates on-hook in the case of a channel in the DT direction, and "1" in the case of a channel in the LC direction.
Assume that "0" indicates ringing transmission and "0" indicates ringing disconnection.

In LC, one bit of the control signal in the channel is extracted to control ringing signal transmission.
Also, off-hook and on-hook signals are inserted into one bit of the control signal in the channel. Such control is performed by signals from the CC when a fixed connection is not made, so it is necessary to switch control signals within the LC depending on whether a fixed connection is made or not.

FIG. 5 shows the configuration of the LC in the conventional system. The control signal bit corresponding to the ringing signal from the TD-NW is taken out to the register (REG) 23 via the dropper (D) 22, and is controlled to be switched by the selector (SEL) 24 together with the control signal from the CC to eliminate the ringing. RG2 is added to the signal sending control circuit 25, and the control circuit 25 thereby
A paging signal from 1 is sent to the subscriber. Also, an off-hook or on-hook signal from a subscriber is detected by an off-hook and on-hook detection circuit 26 and sent to the CC as a control signal bit, or sent to the inserter (I) via a register (REG) 27.
28 into the channel.

Furthermore, in the conventional system, since one bit is provided for a control signal, a memory area for a fixed connection is required in the speech path memory (hereinafter referred to as SPM) in the TD-NW.

FIG. 6 shows the configuration of a TD-NW in a conventional system. The 9-bit signal from the DT passes through the selector (SEL) 29 and is written to the SPM 30 for channel switching as shown in a, and the required channel switching control is performed by the control memory (HLM) 31 for channel switching control. After that,
Output to LC. Therefore, in the SPM 30, 9 bits are required for each channel, which is 1 bit more than when no fixed connection is made. Note that the register (REG) 32 has a 9-bit all-zero signal as a no-call pattern.
When there is no call, this signal is sent to SPM3 via SEL29.
Configured to write to 0.

In this way, in the conventional fixed connection signal processing method, it is necessary to switch the signal path depending on whether a fixed connection is used or not, and therefore an extra signal line is required, which not only requires a large amount of hardware but also makes operation difficult. becomes complicated. Furthermore, an extra memory area is required for the fixed connection, which not only increases cost, but also requires a circuit for the fixed connection even when no fixed connection is required.

The present invention aims to eliminate such drawbacks of the prior art, and its purpose is to eliminate the need for signal path switching depending on whether or not there is a fixed connection, and to reduce the memory area for fixed connections. The purpose is to provide a method that does not require this.

The fixed connection signal processing method of the present invention is based on the TD-NW
By providing an audio signal channel and a control signal channel for fixed connections within the LC, the signal paths are automatically switched, which simplifies the configuration of the LC and saves extra memory space for fixed connections. It is not necessary for this purpose.

Examples will be described in detail below.

FIG. 7 conceptually shows an embodiment of the fixed connection signal processing method of the present invention. TD− for fixed connection
Within NW2, the voice signal channel and fixed connection signal channel are DT4 and LC1, corresponding to the subscribers.
Make a fixed connection between the The channel configuration of this fixed connection signal is performed using specific bits among the 8 bits, as shown in FIG. This signal is input at DT4 in FIG. DT
The configuration of No. 4 consists of a dropper and an inserter, and this is a CCITT standard and is self-explanatory. This fixed connection signal is connected to the
In a channel signal, this signal is inserted into the 8th bit of an 8-bit audio signal once every 6 frames. This signal is separated by the DT4, resulting in two channels: an audio signal channel and a fixed connection signal channel. No fixed connection
In DT, such channel separation is not performed. DT with fixed connection and DT without fixed connection
The hardware configuration itself is different from DT. In Figure 1, TD-NW8 of station Y contains 1
Only a channel is provided, and its ringing control signal, on-hook/off-hook signal becomes a connection control signal with a normal opposite exchange, is sent to CC7, processed there, and sent to the connected subscriber circuit.

FIG. 8 shows an example of the configuration of the subscriber circuit LC in the fixed connection signal processing system of the present invention. In this Figure 8, the inserter (I) 2 uses a fixed connection signal channel different from the audio signal channel.
In order to make it easier to understand the signal flows of 8 and dropper (D) 22, each signal flow of TD-NW is shown separately. The inserter (I) 28 and dropper (D) 22 constitute a fixed connection signal circuit 34. This LC
can be used for both fixed and non-fixed connections. The LC has a circuit for an audio signal channel and a circuit for a fixed connection signal channel. Here, a fixed connection is a state in which ringing signals are sent and on-hook and off-hook detection signals are exchanged with the opposite exchange, completely unrelated to the control device of the exchange, and a non-fixed connection is a state in which ringing signals are transmitted and on-hook and off-hook detection signals are exchanged with the opposite exchange, regardless of the control device of the exchange. This refers to the state in which it controls whether or not to send a signal, and sends on-hook and off-hook detection signals to the control device of the exchange.

In the case of ringing signal transmission processing, when a fixed connection is established, the control device CC recognizes that this LC is in a fixed connection state, and the control device CC sends a “0” signal.
Send it to the OR circuit 33 of LC1. From the TD-NW, the fixed connection signal channel is connected to the fixed connection signal circuit 34 of LC1, and the dropper (D) 22 in LC1 is connected to the fixed connection signal circuit 34 of LC1.
The ringing control signal is separated from the fixed connection signal channel and sent to the OR circuit 33. This ringing control signal is a repeating signal of "1" and "0", and since the signal from CC is always "0",
A ringing control signal, which is a fixed connection signal, from the TD-NW is sent to the ringing transmission control circuit 25 via the OR circuit 33, and ringing is performed for the subscriber according to the signal from the opposite exchange. On the other hand, when the connection is not fixed (non-fixed connection),
As shown in Figure 9, CC switches SEL29 to the exchange control memory indicated by HLM31 and REG3
2, and the TD-NW writes all "0"s, which are the contents of REG32, into the fixed connection signal channel of the SPM 30. At this time,
Contrary to the fixed connection, the signal from the dropper (D) 22 is always "0", so the ringing control signal, which is a repeating signal of "1" and "0" from CC, passes through the OR circuit 33 and becomes a ringing signal. The signal is sent to the transmission control circuit 25, and ringing is performed to the subscriber according to the signal from the CC.

Off-hook and on-hook detection circuit 2 which then detects the calling and dialing pulses of that subscriber.
At the same time, the control signal from 6 is inserted into the fixed connection signal channel via the inserter (I) 28.
Output in parallel to control device CC. When the LC is used for a fixed connection, the CC does not perform any processing on the signal to the CC, and only the signal on the fixed connection signal channel is sent to TD at a particular bit on the channel in Figure 10. - It is sent to the opposite exchange via the NW 2, DT 4 and digital trunk line 6, and the exchange performs signal detection processing, dial tone transmission and outgoing connection processing.

On the other hand, when the connection is not fixed (non-fixed connection), the CC does not connect the fixed connection signal channel to the fixed connection signal circuit 34 of the LC. and C.C.
Off-hook and on-hook are processed in , and dial tone transmission and outgoing connection processing are performed.

Figure 11 shows the inserter (I) 28 and dropper (D).
22 circuit examples are shown. The inserter circuit uses an 8-bit shift register to convert a parallel signal into a serial signal, and always inputs a 0 level signal to bits 0 to 6, and also inputs an off-hook and on-hook signal from the off-hook and on-hook detection circuit 26 to the 7th bit. Input the signal.

The dropper circuit uses an 8-bit shift register to convert serial signals to parallel signals.
A 0 level signal is always outputted from the 0th to 6th bits, and a ringing control signal is outputted from the 7th bit. In this way, in the LC of the present invention,
A selector is not required for switching control signals, and only an OR circuit is required.

FIG. 9 shows an example of the configuration of a TD-NW in the fixed connection signal processing system of the present invention. The 8-bit audio signal channel and the fixed connection signal channel from the DT are respectively written to the SPM 30 as shown in a and b through the SEL 29,
Replacement control is performed by the HLM 31 and output to the LC. Therefore, an 8-bit configuration is sufficient for the SPM 30, and no extra memory area is required. Note that when there is no call, an all-zero no-call pattern is written from the REG 32 to the SPM 30 via the SEL 29, as in the case of FIG.

As explained above, according to the fixed connection signal processing system of the present invention, it is not necessary to switch the signal path depending on whether there is a fixed connection, and therefore the configuration of the subscriber circuit is simplified. It is also advantageous because no extra memory area is required for fixed connections.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram conceptually showing a fixed connection in a time division switch, Fig. 2 is an explanatory diagram showing a fixed connection in a space division switch, and Fig. 3 is a block diagram conceptually showing a conventional fixed connection signal processing system. Figure, 4th
5 is a block diagram showing the structure of a subscriber circuit in the conventional method. FIG. 6 is a block diagram showing the structure of the time division network in the conventional method.
FIG. 7 is a block diagram showing an embodiment of the fixed connection signal processing method of the present invention, FIG. 8 is a block diagram showing an example of the configuration of a subscriber circuit in the method of the present invention, and FIG. 9 is a block diagram showing an example of the structure of the subscriber circuit in the method of the present invention. FIG. 10 is a diagram showing a channel bit configuration of a fixed connection signal, and FIG. 11 is a diagram showing an example of a time division network configuration in
Inserter (I) 28 and dropper (D) 2 shown in the figure
FIG. 2 is a diagram showing a second circuit example. 1, 9... Subscriber circuit (LC), 2, 8... Time division network (TD-NW), 3, 7... Control device (CC), 4, 5... Digital terminal (DT), 6...Digital trunk line, 11...Space division network (SD-NW), 12...Digital trunk line, 13...Channel bank, 21...
Ringing signal generator (RG), 22...Dropper (D),
23, 27, 32...Register (REG), 24,
29... Selector (SEL), 25... Ringing signal transmission control circuit, 26... Off-hook and on-hook detection circuit, 28... Inserter (I), 30
...Speech path memory (SPM), 31...Control memory (HLM), 33...OR circuit.

Claims (1)

[Scope of Claims] 1. In a digital trunk line in a time division exchange, a subscriber circuit, and a digital communication path in which a plurality of sets of channels connecting the digital trunk line and the subscriber circuit are digitally multiplexed, Connecting the digital trunk line and the subscriber circuit using the two channels by allocating two channels of the multiplexed channels of the same number of bits to a voice signal channel and a control signal channel, respectively; A repeating signal of 1 and 0, which is a ringing control signal generated in the opposing exchange connected via the digital trunk line and sent to the subscriber circuit via the digital communication path, and a signal generated in the control device of the own exchange. The subscriber circuit is provided with an OR circuit that inputs a repeating signal of 1 and 0, which is a ringing control signal sent to the subscriber circuit, and disables the ringing control signal from the local exchange control device when the connection is fixed. (“0”) and transmits the ringing control signal sent via the dropper using a specific bit in the control signal channel for fixed connection from the destination exchange control device transmitted via the digital communication path. On the other hand, when the connection is non-fixed, the control signal channel receives a no-call pattern (all 0s) in the digital communication path.
The OR circuit inserts a signal and sets a specific bit in the control signal channel for fixed connection to 0, and the OR circuit extracts the ringing control signal for non-fixed connection from the local exchange control device. By controlling the circuit, the ringing signal is sent out, and the on-hook and off-hook signals detected in the subscriber circuit and sent to the controller (CC) of the local exchange are sent to the control signal channel for the fixed connection. An inserter is installed in the subscriber's circuit that uses specific bits to send the signal to the other party's exchange controller via the digital communication path and the digital trunk line, and when the connection is fixed, the own exchange controller sends control signals to the own exchange. It performs internal processing that is always ignored, and also performs processing to detect on-hook and off-hook in the other exchange by sending control signals to the other exchange via the inserter.On the other hand, when a non-fixed connection is established, the CC transmits the fixed connection signal channel to the subscriber. A fixed connection signal processing method that is characterized by performing on-hook and off-hook detection processing in the control device of the local exchange using control signals to the local exchange without connecting to the fixed connection signal circuit of the circuit (LC).