JPH0220130A - Adpcm transcoder - Google Patents

Abstract

PURPOSE:To prevent occurrence of the shutting-out phenomenon when an ADPCM uncodable signal is transmitted by separating an ADPCM codable and uncodable signals, transmitting with an ADPCM transmission line after the former converts the code and transmitting with a PCM signal transmission line when the latter is in the condition of the PCM signal. CONSTITUTION:When a PCM signal inputted from PCM primary group signal input terminals 3 and 4 is an ADPCM codable signal, after it is code-converted to an ADPCM signal by a CODEC circuit 9, it is outputted from an ADPCM primary group output terminal 12 to an external part. At the time of the ADPCM uncodable signal, it is branched by a branching inserting circuit 23 and outputted through a PCM primary group output terminal 25 to the external part. The ADPCM signal inputted from an ADPCM primary group signal input terminal 15 is code-converted to a PCM signal by the CODEC circuit 9 and inputted from a PCM primary group signal input terminal 26. The ADPCM uncodable signal is branched by the branching inserting circuit 23, the signals are constituted to a PCM primary group signal format with a format converting circuit 8 and outputted from PCM primary group signal output terminals 19 and 20.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to ADPCM transcoders, and in particular to ADPCM transcoders.

The present invention relates to measures to prevent so-called lock-out that occurs when transmitting signals that cannot be encoded using ADPCM. .

[Conventional technology]

Conventionally, this type of ADPCM) Lancecoder.

When transmitting a signal that cannot be encoded as an ADPCM, the signal that cannot be encoded as an ADPCM signal is transmitted as a PCM signal using two time slots of the ADPCM signal format.

[Problem that the invention seeks to solve]

As mentioned above, in the case of a conventional ADPCM) transcoder, when transmitting an ADPCM non-encodable signal.

In order to transmit the PCM signal as it is, it is necessary to use two time slots of the ADPCM signal format. Therefore, when data is transmitted using an ADPCM) transcoder, if there is one channel on which an ADPCM unencodable signal is transmitted, the number of channels on which an ADPCM encodeable signal is transmitted is reduced by one (in other words, it is shut out). , Therefore, there is a problem that the number of transmittable channels is reduced by the number of signal channels that cannot be encoded with ADPCM.

[Means for solving problems]

ADPCM of the present invention) In the transcoder, the receiving PCM
The primary group signal is input, code-converted to an internally processed code, and outputted from the format conversion section (described later). Transmission P
and a PCM line interface unit that converts the code of the CM primary group signal onto a transmission line and outputs it to the outside.

ADPCM receiver' (7-tap) inputs all received ADPCM primary group signals and converts them into internally processed codes, and also converts the transmitted ADPCM primary group signals output from the format converter (described later) into transmission line codes and outputs them to the outside. 7 Ace HfS inputs the output of the PCM line interface section, extracts signaling information and alarm information, and then outputs it to the C0DEC' section, which will be described later.
The ADPCM signal output from the ODEC section is input, and the AD
After format-converting the PCM signal into a predefined ADPCM signal format, it is output to the ADPCM line interface section, while receiving the received ADPCM signal output from the ADPCM line interface section and extracting signaling information and alarm information, and then outputting it to the C0DEC5. At the same time, the PCM signal output from the CODEC section and the ADPCM unencodable signal output from the add/drop circuit, which will be described later, are input, and a PCM signal 7 ohms is generated according to the output from the channel arrangement control circuit, which will be described later. a format converter that outputs the PCM line input signal to the PCM line input/receiving section; and a format converter that converts the PCM signal output from the format converter into an ADPCM signal and outputs the ADPCM signal from the format converter.
A CODEC unit that converts the code of a DPCM signal into a PCM signal, and a CODEC unit that inputs the output of the format conversion unit and converts the code of the DPCM signal into a PCM signal.
Extract the ADPCM IP unencodable signal from the primary group signals and output the number of channels to a channel arrangement control circuit to be described later.1. Arranging the ADPCM non-encodable signals and the number of channels according to the output from the channel arrangement control circuit and outputting them to a separately provided PCM line interface circuit, and outputting them from the separately provided PCM line interface circuit. A separately provided PCM primary group signal board 100 is provided, and the channel number information extracted therefrom is output to a channel arrangement control circuit to be described later.

ADPCM according to the output from the channel arrangement control circuit
A drop-and-add unit that separates unencodable signals; and input of channel number information from the drop-and-add unit.

A channel arrangement control circuit that controls the channel arrangement of the PCM primary group signal, the ADPCM primary group signal, and the separately provided PCM primary group signal, and the A and DPCM codes transmitted through the separately provided PCM primary group signal transmission path. It has a separately provided PCM line interface circuit that receives a signal that cannot be converted into an internal processing code, converts the code into an internal processing code, and converts the output signal from the two-branch/add circuit into an all-transmission line code.

〔Example〕

Next, the present invention will be explained with reference to examples.

FIG. 1 is a diagram showing an embodiment of the present invention (when three systems are implemented).

With reference to FIG. 1, l, 2, 3, 4.5. and 6 are PCM primary group signal input terminals, 7 PCM line interface circuits (PLI), 8 H format conversion circuits (F'MT), 9 are CODEC circuits, 10 are ADPCM line interface circuits, 11, 12° and 13 are ADPCM primary group signal output terminals, respectively.

! 4,15. and 16 ADPCM primary group signal input terminals, 17.18, 19.20, 21. and 22 are PCM primary group signal output terminals, and 23 is a branch/add circuit.

24 is an ADPCM coded non-codable signal layer line interface circuit, 25 is an ADPCM coded non-codable signal layer, 26 is an input terminal for the ADPCM 1 codeable signal, and 27 is a channel arrangement control circuit. (CHCON
T).

PC input from PCM primary group signal input terminals I and 2
The M signal is converted by the PCM line interface circuit 7 from a transmission line code to an internally processed code, subjected to alarm detection and synchronization processing, and then input to the format conversion circuit 8 .

The format conversion circuit 8 extracts the signaling information of the input PCM signal, adjusts the timing for processing in the CoDFC circuit 9, and converts this signaling information into a C
Output to the ODEC circuit 9.

The CODEC circuit 9 converts the 8-bit PCM signal of each channel into a 4-bit ADPCM signal and outputs it to the format conversion circuit 8 again.

In the format conversion circuit 8, the channel array control circuit 27
According to the channel arrangement information output from CoDF
The International Telegraph and Telephone Consultative Committee (CCITT:
tional Telegraph and Telegraph
phone consultant
e) Configuring the ADPCM signal format as described in Recommendation G.761.

It is output to the ADPCM line/interface circuit 10.

At this time, an ADPCM unencodable signal (for example, digital data or 9600
If a high-speed voice band modem signal of bps or higher is included, this signal is branched by the add/drop circuit 23, so to speak.
The signal is not ADPCM encoded and is outputted to the outside from the PCM primary group signal output terminal 7J via the PCM line interface circuit 24. Therefore, the format conversion circuit 8 inserts an idle code into the corresponding channel.

ADPCM line interface circuit 10 transmits A
ADP converts the DPCM primary group signal into a transmission line code
It is output to the outside from the CM primary group signal output terminal 11. .

Further, the received ADPCM signal inputted from the ADPCM primary group signal input terminal 14 is converted from a transmission line code to an internal processing code by the ADPCM line interface circuit 10, is subjected to alarm detection and synchronization processing, and is sent to the format conversion circuit 8. Enter! 'I'm sure.

The format conversion circuit 8 extracts the /bnaring information of the input ADPCM signal, adjusts the timing for processing in the CODEC circuit 9, and converts this 7gnaly/g information to C.
Output to the ODEC circuit 9.

(4 pins for each channel in CODEC circuit 9) ADPC
The M signal is code-converted into a PCM signal (8 bits) and outputted to the format conversion circuit 8 again.

In the format conversion circuit 8, the channel array control circuit 27
The PCM signal output from the CODEC circuit '1NI9 according to the channel arrangement information output from the input ADPC
Constructs the signal format of the PCM primary group signal specified in CCITT Recommendation G, 704 from the Siddering information and Allano information extracted from the M signal and the ADPCM unencodable signal extracted from the add/drop circuit 23. and outputs it to the PCM line interface circuit 7.

At this time, the add/drop circuit 23, which will be described later, inputs an ADPCM unencodable signal input from the PCM primary group input terminal 26.
If a DPCM unencodable signal is not detected, the format conversion circuit 8 allocates the output signal from the CODEC circuit 9 to the corresponding channel instead of the output signal from the add/drop circuit 23.

The PCM line interface circuit 7 converts the transmission PCM primary group signal outputted from the format conversion circuit 8 into a transmission line code, and outputs it to the outside from PCM primary group signal output terminals 17 and 18.

Similarly, if the PCM signal input from the PCM primary group signal input terminals 3 and 4 is an ADPCM encodeable signal, it is code-converted into an ADPCM signal by the CODEC circuit 9 and then sent to the outside from the ADPCM primary group signal output 1 12. is output to. On the other hand, if the signal cannot be encoded using ADPCM, it is branched by the add/drop circuit 23 and outputted to the outside via the PCM primary group signal output terminal 25.

AD input from ADPCM primary group signal input terminal 15
The PCM signal is code-converted into a PCM signal by the CoDFC circuit 9 and inputted from the PCM primary group signal input terminal 26. ADPCM unencodable signals are branched by a branch/add circuit 23, and these signals are configured into a PCM primary group signal format by a format converter circuit 8.
The signals are output from the PCM primary group signal output terminals 19 and 20 to the outside.

Similarly, if the PCM signal input from the PCM primary group signal input terminals 5 and 6 is an ADPCM encodeable signal, it is converted into an ADPCM signal by the CODEC circuit 9, and then sent from the ADPCM primary group signal output terminal 13. On the other hand, if it is a signal that cannot be encoded using ADPCM, it is branched by the add-drop circuit 23 and outputted to the outside via the PCM primary group output terminal 25.

AD input from ADPCM primary group signal input terminal 16
The PCM signal is code-converted into a PCM signal by the CODEC circuit 9, while the ADPCM unencodable signal inputted from the PCM primary group signal input terminal 26 is sent to the add/drop circuit 2.
3, and these signals are configured into a PCM primary group signal format in a format conversion circuit 8 and converted into a PCM primary group signal format.
The signals are output from the primary group signal output terminals 21 and 22 to the outside.

In the branch/add circuit 23, the PCM primary group input terminal 1゜2.3
, 4. Only ADPCM unencodable signals are extracted from the PCM primary group signals input from 5 and 6, and rearranged into the signal format shown in FIG. 2 according to the channel arrangement information output from the channel arrangement control circuit 27. The ADPCM unencodable signal inputted from the PCM primary group input terminal 26 and having the signal format shown in FIG. 2 is extracted.

In Figure 2, the ADPCM of the maximum 10 channel per two PCM primary group signals (expressed as a system in the figure)
A signal format is shown that allows the transmission of non-codable signals.

Referring to FIG. 2, time slot 0 is for transmitting the framing pattern and the number of transmission channels of the ADPCM non-encodable signal, and time slot 16 is for transmitting the framing pattern and the number of transmission channels for the ADPCM non-encodable signal.
This is for transmitting bunaling information.

By the way, channels that can transmit ADPCM non-encodable signals per system are based on the original PCM primary group signal channel of channel assignment specified in International Telegraph and Telephone Advisory Committee Recommendation G, 761 TABLE 7/G, 761. If we use 10 channels, we can transmit the number of channels of ADPCM non-encodable signals to the opposite station.

The opposite station can decode the channel correspondence between the ADPCM unencodable signal and the PCM primary group signal from this channel assignment.

An example of this is shown in FIG. 3, where Nl, N2 . N3. With N4 and N5 bits,
System 1, that is, ADPC contained in the PCM primary group signals input from PCM primary group input terminals 1 and 2.
M indicates the total number of non-encodable signals, N1, N2, N3, N4 and N5 of frame 5 and frame 7, ie system 2.

Indicates the total number of ADPCM unencodable signals included in the PCM primary group signals input from PCM primary group input terminals 3 and 4, and Nl and N of frames 9 and 11.
2. N3. System 3 or PCM with N4 and N5 bits
The total number of ADPCM unencodable signals included in the PCM primary group signals inputted from the primary group input terminals 5 and 6 is shown.

This results in 2, for example, N1=N2=N3=0°N4=
If N5=1, the total number of ADPCM unencodable signals is 3, so channels 6 and 22 of the PCM primary group signals inputted from the PCM primary group input terminal 1 and input from the PCM primary group input terminal 2 are It can be seen that channel 6 of the PCM primary group signal transmits an ADPCM unencodable signal.

For example, the signal format shown in FIG.
If a signal that cannot be encoded by CM is to be transmitted, a conventional ADPCM transcoder can transmit only 150 channels in total for the three systems because the transmission capacity is reduced by the amount of signal channels that cannot be encoded by ADPCM, but with the present invention. For example, it is possible to transmit up to a maximum capacity of 180 channels.

〔Effect of the invention〕

As explained above, in the present invention, ADPCM encodeable signals and ADPCM unencodable signals are separated.

The former is code-converted to ADPCM, and then format-converted to the signal format specified by CCI TT.

The latter is transmitted using the ADPCM transmission path, while the latter is transmitted using the PCM transmission path.
By format-converting the signal as it is into a predetermined signal format and transmitting it using a PCM signal transmission path, it is possible to prevent the lock-out phenomenon that occurs when transmitting an ADPCM-encodable OT signal. be.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of an ADPCM) transcoder of the present invention, FIG. 2 is a diagram showing a signal format used in the present invention, and FIG. 3 is a diagram showing a frame format used in the present invention. be. 1.2, 3, 4, 5, 6.26... PCM primary group signal input terminal, 7.24... PCM line inter 781 circuit (PLI), 8... Format conversion circuit (F
M? ). 9...CoDFC circuit, 10-ADPCM line interface circuit (ALI), 11, 12,
l 3... ADPCM primary group signal output terminal, 14,1
5.16... ADPCM primary group signal input terminal, 17,
18, 19, 20, 21. 22.25... PCM primary group signal output terminal, 23...
- Branch/add circuit (D/I), 27...Channel array control circuit (CHCONT).

Claims (1)

[Claims] 1. A PCM line interface unit which receives a received PCM primary group signal, converts the received PCM primary group signal into a predetermined internal processing code, converts the transmitted PCM primary group signal into a transmission line code, and outputs the converted signal. and receive A
an ADPCM line interface unit which receives a DPCM primary group signal, converts the received ADPCM primary group signal into a predetermined code, converts the transmitted ADPCM primary group signal into a transmission line code, and outputs the same;
An internal processing code from the M line interface unit is input, signaling information and alarm information are extracted from the internal processing code, an ADPCM signal is input, and the ADPCM signal is format-converted into a predefined ADPCM signal format. While being output to the ADPCM line interface unit, the received ADPCM signal output from the ADPCM line interface unit is input, and the signaling information and alarm information are extracted, and the PCM signal and the ADPCM non-codable signal are input, and the PCM signal is a format conversion section that configures a format and outputs it to the PCM line interface section; and a format conversion section that converts the PCM signal outputted from the format conversion section into an ADPCM signal and converts the ADPCM signal outputted from the format conversion section into a PCM signal. A CODEC unit that performs code conversion and the output of the format conversion unit are input, extracts the ADPCM unencodable signal from the PCM primary group signal, outputs the number of channels thereof, and outputs the ADPCM unencodable signal from the PCM primary group signal. While arranging and outputting the signal and the number of channels, P
receiving the CM primary group signal and outputting channel number information;
a drop/add unit that separates an ADPCM unencodable signal;
The channel number information from the add/drop unit is input, and the PCM
a channel array control circuit that controls channel arrays of the primary group signal, the ADPCM primary group signal, and the PCM primary group signal;
a PCM line interface circuit that receives an ADPCM unencodable signal transmitted through a PCM primary group signal transmission line and converts the code into the internal processing code, and converts the output signal from the add/drop unit into the transmission line code; An ADPCM transcoder comprising: