JPH0470137A - Signaling transmission system - Google Patents

Abstract

PURPOSE:To suppress the deterioration of characteristics in the case of in-sloting by transmitting signaling while not being sampled at comparatively high speed but by being coded to a character. CONSTITUTION:On the transmission part, a signaling recognition part 1 receives signaling and recognizes the number of dial pulses, a code conversion part 2 converts the number of dial pulses to the character composed of a prescribed code, and an encoder part 3 transmits signaling after inserting this character to a sound code. On the reception side, a decoder part 4 separates the inserted character from the received sound code, a code restorage part 5 converts the character to the number of dial pulses, and a signaling reproduction part 6 reproduces signaling from a reference dial pulse corresponding to this number of dial pulses. Therefore, the bit rate of signaling to be transmitted by in-slot can be lowered. Thus, the deterioration of the sound signal characteristics can be suppressed.

Description

[Detailed Description of the Invention] [Summary] The purpose of the present invention is to provide a signaling transmission method that prevents deterioration of voice signal quality by reducing the rate of pit steals, and which is capable of receiving signaling and dialing. A signaling recognition unit that recognizes the number of pulses, a code conversion unit that converts the recognized number of dial pulses into a character consisting of a predetermined code, and an encoding unit that inserts the character into a voice code and transmits it on the transmitting side. and a decoding unit that separates the inserted character from the received voice code, a code restoring unit that converts the separated character into a dial pulse number, and a reference dial pulse according to the dial pulse number. The receiving side is provided with a signaling reproducing unit that reproduces the signaling from the received signal.

[Industrial application field]

The present invention relates to a system for transmitting signaling, and more particularly to a signaling transmission system in which signaling is converted into characters and transmitted along with voice codes in an in-person system. .

In recent years, as the quality of voice transmission has improved, the signaling transmission method has been shifting from the conventional in-slot transmission method to the out-slot transmission method.

However, there is still a strong demand for the in-slot method in devices such as TDM that aim to efficiently utilize lines.

Therefore, there is a need for a signaling transmission system that can perform in-slot transmission of signaling and high-quality voice transmission.

[Prior Art] As a signaling transmission method in a conventional audio coding transmission system, a method is generally used in which data obtained by sampling the signaling at a constant cycle is inserted as is into the audio code using an in-slot method and transmitted. There is.

For example, in the conventional in-slot 32 kbps compression coding transmission system, a voice code is pit-stealed once every eight frames, and data obtained by sampling the signaling is embedded therein and transmitted.

[Intelligence B that the invention attempts to solve] However, in this type of system, there is a large proportion of pit steals, so when communicating using equipment such as MODEM or FAX, there is a problem that the quality of the transmitted signal deteriorates significantly. is occurring.

The present invention aims to solve the problems of the prior art, and is capable of preventing deterioration of audio signal quality by reducing the pit steal rate in an in-slot signaling transmission system, and also improving signaling. The purpose is to provide a signaling transmission method that allows correct transmission.

[Means to solve the problem]

As shown in FIGS. 1(a) and 1(b), the basic configuration of the present invention is such that, on the transmitting side shown in FIG. 1(a), a signaling recognition unit 1 receives signaling and recognizes the number of dial pulses. The code converter 2 converts the recognized dial pulse number into a character consisting of a predetermined code, and the encoder 3 inserts this character into a voice code and transmits it.

On the receiving side shown in (b), the decoding section 4 separates the inserted characters from the received voice code, and the code restoring section 5 converts the separated characters into a dial pulse number and reproduces the signaling. The section 6 reproduces signaling from the reference dial pulses in accordance with the number of dial pulses.

Further, in the above-described configuration, the present invention converts the off-hook or on-hook state into a character consisting of a predetermined code in the code conversion section 2, and restores this character into a signal indicating the off-hook or on-hook state in the code restoration section 5. It was designed to do so.

[Effect]

The transmitting side receives the signaling, recognizes the number of dial pulses, converts the recognized number of dial pulses into a character consisting of a predetermined code, inserts this character into the voice code, encodes it, multiplexes it, and transmits it. .

On the receiving side, the inserted characters are separated from the received voice code, the separated characters are converted to the number of dial pulses, and the signaling is reproduced from the reference dial pulse according to the number of dial pulses, so the in-slot Therefore, the bit rate of the signaling to be transmitted can be lowered, and therefore the deterioration of the characteristics of the audio signal can be minimized.

Further, in the above invention, the transmitting side converts the off-hook or on-hook state into a character consisting of a predetermined code and transmits it through an in-slot, and the receiving side restores this character to a signal indicating the off-hook or on-hook state. As a result, the signaling status on the transmitting side can be accurately conveyed to the receiving side.

〔Example〕

FIG. 2(a) shows the configuration of an embodiment of the present invention, and shows an in-slot audio transmission device, where (a) is the transmitting side and et al. is the receiving side. be.

In the second part, on the transmitting side shown in (a), 11 is a counter, for example, composed of a binary counter,
Count the number of dial pulses. Reference numeral 12 denotes a buffer section, which is composed of, for example, a flip-flop, and stores the count value of the counter 11.

13 is a codebook, which is a read-only memory (R
OM) and stored in the buffer section 12.
<Convert the number of spaces into a predetermined code and output it. The code book 13 also stores codes indicating off-hook or on-hook states.

14 is a format conversion unit, which is composed of a shift register, and converts the output data of the codebook 13 into 64kP.
It is converted into a CM signal and output in response to the S Out pulse. Reference numeral 15 denotes a KOG consisting of an LSI, which inserts the signaling data SIG from the format converter 14 into an audio code consisting of a 64k PCM signal from an audio section (not shown) in slot, and converts the signal into a 32 kADPC.
Convert to M signal and output.

On the receiving side shown in FIG. 2 (b), 16 is L
A decoder consisting of an SI, the input 32kAD
The PCM signal is converted into a 64k PCM signal and outputted to an audio section (not shown), and the signaling data S.G. inserted in the in-slot is separated. Reference numeral 17 denotes a format converter, which is composed of a shift register and which converts signaling data STG consisting of a 64kPCM signal.
is converted into a predetermined code according to the pulse.

Reference numeral 18 denotes a buffer section, which is composed of, for example, a flip-flop, and stores the code output from the format conversion section 17.

A codebook 19 is composed of a ROM, and converts the code stored in the buffer section 18 into the number of pulses and outputs the same. In the code book 19, codes corresponding to off-hook or on-hook are also converted into signals indicating off-hook or on-hook, respectively, and output. Reference numeral 20 denotes a counter, for example, a binary counter, which counts reference dial pulses from a reference dial pulse generator (not shown) according to the number of pulses output from the codebook 19, and outputs a mask signal at the end of the count. Occur. Reference numeral 21 denotes a dial pulse restoring section, which is composed of a gate, and starts outputting a reference dial pulse when converting the code in the codebook 19, and stops outputting when a mask signal is generated from the counter 20, thereby converting the encoder into an encoder. Regenerate the signaling input at.

FIG. 3 is an example of a codebook, and shows that on-hook, numbers 0 to 9, and off-hook are represented by 4-pinto binary codes.

FIGS. 4(a) to (C) show signals of various parts in the embodiment of FIG. 2, where (a) shows a dial pulse, Φ) is on the transmitting side, and (C) is on the receiving side. The signals of each part are shown.

The dial pulses are generated at intervals of the timer value t, as shown in FIG. 4(a). The timer value t is generally called a minimum pause, and since the next digit pulse will not arrive within this time, the count value of the counter 11 is latched in the buffer section 12 when this period has elapsed. .

In normal operation, on the transmitting side, when the timer value t has elapsed, the count value of the counter 11 is latched in the buffer unit 12, and signaling is recognized. Then, it is converted into a code (character) by referring to the code book 13, and outputted as 4-bit data through the format converter 14 in synchronization with the system clock 4007.

In Fig. 4(b), code 5 '0101°' is output in response to the number of dial pulses '5', and code 7 '0111°' is output in response to the number of dial pulses '7'. It has been shown that

In the KOG 15, the signaling data SIG consisting of a 64 kbps PCM signal from the format converter 14 is inserted into the 64 kbps PCM signal of the audio signal, converted into a 32 kbps ADPCM signal, and transmitted.

On the receiving side, the decoder 16 converts the 32 kbps ADPCM signal into a 64 kbps PCM signal and separates the signaling data SIG.
7, it is converted into a code (character) and held in the buffer section 18, and is converted into the number of dial pulses with reference to the code book 19.

Then, the counter 20 and the dial pulse restoring section 21 reproduce the signaling by outputting reference dial pulses equal to this number of dial pulses.

In FIG. 4(C), as signaling, a dial pulse of "5" is output in response to code 5 "0101", and a dial pulse of "7" is output in response to code 7 "0111". It has been shown that

Furthermore, on the transmitting side, if the signaling is fixed in an off-hook or on-hook state, a code indicating off-hook is issued, as shown in Figure 4 (°C).
1111” or the code “o o
The receiving side can restore this and generate a signal indicating off-hook or on-hook, as shown in Figure 4(C), so the receiving side can correctly check the signaling status. can convey.

FIGS. 5(a) and 5(b) are diagrams illustrating the timing of the bin-to-steel operation according to the present invention, in which (a) shows the transmitting side and (b) shows the receiving side.

As shown in (a), in response to the bit steal timing signal number that occurs once in eight times on the transmitting side, 64
It is shown that by inserting signaling into an audio signal consisting of kPCM in slot, the signal is converted into an audio signal consisting of 32k ADPCM and sent out, with a signaling bit inserted as shown by diagonal lines. .

As shown in (b), on the receiving side, the same 8
According to the Bi-not-Style timing signal that is generated once per cycle, the signaling bits are extracted from the audio signal consisting of 32 kADPCM, the signaling is reproduced, and the signal is converted into an audio signal consisting of 64 kPCM and output. .

FIG. 6 shows an example of the configuration of the dial pulse restoring section, in which 31 is a timing pulse generator, 32 is a pulse mask circuit, and 33 is a selector.

The timing pulse generator 31 generates a signal indicating the timing of in-slot insertion of signaling. The pulse mask circuit 32 allows the timing signal from the timing pulse generator 31 to pass when an instrument is set, and masks the timing signal in other cases. Selector 33
receives the out-slot ADPCM signal and signaling signal, and normally selects the ADPCM signal, but
ii When a timing signal is generated from the pulse mask circuit 32,
By selecting a signaling signal, an ADPCM multiplied signal of the in-slot into which the signaling is inserted is output.

[Effects of the Invention] As explained above, according to the present invention, the signaling is coded into characters and transmitted without being sampled and transmitted at a relatively high speed, so the bit rate of the signaling can be lowered. Therefore, it is possible to minimize the deterioration of characteristics when inserted. Furthermore, since the off-hook or on-hook status on the transmitting side can be coded into characters and transmitted to the receiving side, the signaling status can be accurately conveyed. The present invention greatly contributes to improving the performance of an in-slot audio transmission device.

[Brief explanation of drawings]

FIGS. 1(a) and (b) are diagrams showing the basic configuration of the present invention, FIGS. 2(a) and (b) are diagrams showing an embodiment of the present invention, and FIG. 3 is a diagram illustrating a codebook. Figure 4(a),
(b). (C) is a diagram showing the signals of each part in the embodiment of FIG. 2, FIGS. 5(a) and (b) are diagrams showing the timing of pit steal according to the present invention, and FIG. 6 is an example of the configuration of the dial pulse restoring section. FIG. 1 is a signaling recognition section, 2 is a code conversion section, 3 is an encoding section, 4 is a decoding section, 5 is a code restoration section, and 6 is a signaling reproduction section.

Claims (2)

[Claims] (1) A signaling recognition unit (1) that receives signaling and recognizes the number of dial pulses; a code conversion unit (2) that converts the recognized number of dial pulses into a character consisting of a predetermined code; Encoding unit that inserts into the code and transmits it (
3) on the transmitting side, a decoding unit (4) that separates the inserted characters from the received voice code, and a code restoring unit (5) that converts the separated characters into a dial pulse number. ), and a signaling reproducing unit (6) for reproducing signaling from a reference dial pulse according to the number of dial pulses on a receiving side. (2) The code conversion unit (2) converts the off-hook or on-hook state into a character made of a predetermined code, and the code restoration unit (5) restores the character to a signal indicating the off-hook or on-hook state. The signaling transmission system according to claim 1, characterized in that: