JPH03108827A - Transmission system setting system - Google Patents

Abstract

PURPOSE:To allow the operator to attain automatic setting surely without visiting a remote station by using frame bits so as to send a setting data such as a transmission code or the like without malfunctioning the synchronization forward protection. CONSTITUTION:When one multi-frame is taken as one stage, it is discriminated at first as out of synchronism in the case that synchronization is detected consecutively for n-stage, then hunting operation is transited. When the synchronization is dissident for only one stage among n-stages, it is not discriminated as out of synchronism but the synchronization state is continued. The forward protection of the synchronization circuit to send a setting data for converting a transmission code of a receiver from an AMI code into a B8ZS code. A pattern detection circuit 31 separates a setting data added by a transmitter 11 from an inputted signal and supplies the resulting data to terminals 32-1-32-12 of setting changeover section 32 is parallel. The setting changeover section 32 switches the setting of the AMI code and the B8ZS code.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transmission method setting system for controlling a transmission method on a receiving side by remote control on a transmitting side.

[Conventional technology]

For example, when primary group PCM (pulse code modulation) transmission is performed, two transmission signals generated by a terminal device are converted into codes that match the characteristics of the transmission path and then transmitted.

The code format for transmitting signals is AMI specified in G701 of the CCITT (International Telegraph and Telephone Consultative Committee) recommendation.
code, and the B8ZS code specified in the same <0703.

The AMI code alternately transmits 1; positive and negative polarity codes each time a double code "l" occurs. On the other hand, the B8ZS code extracts a block of eight consecutive 0's from a bipolar code string and replaces it with a special code pattern prepared separately, and is different from the AMI code except for this code replacement. are the same. Therefore, in general, transmission equipment using the B8ZS code can change the AMI by switching.
Transmission using codes is also possible.

When switching the transmission code of data transmitted between such code-switchable transmission devices, a switch, etc. is installed on the board on which the encoding circuit is mounted, and settings are made manually. . When the transmission code is switched, a predetermined test signal is transmitted when the line is opened, and the same transmission code is set on both the transmitting and receiving sides, and a line opening test is performed to see if the signal is transmitted normally. If it is confirmed in the line opening test that no errors occur during the transmission of the test signal, the line will be opened as if a normal transmission code has been set.

[Problem to be solved by the invention]

The test signal transmitted in such a line opening test usually uses a general signal pattern transmitted over the line. For example, when an audio signal is transmitted, the test signal rarely has consecutive "0"s, but is often all "1"s. For this reason, even if a test signal is sent using the B8ZS code, the code conversion described above will not be performed because there will not be 8 or more consecutive "0" bits, and a test signal with the same code as the AMI code will be sent out. .

Therefore, even if an incorrect transmission code is set and the settings of the transmitting side device and the receiving side device are different, the setting error may not be discovered depending on the test signal used when the line is opened. If a line was opened with incorrect settings and the error was discovered after the service was put into service and the settings were to be changed, it was necessary to disconnect all lines and perform a switch operation, and the service had to be stopped. .

Furthermore, in the past, a maintenance person had to go to the equipment to set the transmission code of a remote station, which was a very time-consuming and difficult task.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a transmission method setting system that allows the setting of a transmission device to be set without error by remote control.

[Means to solve the problem]

The transmission method setting system of the present invention includes (i) a pattern generation circuit that generates a predetermined pattern signal in synchronization with a frame signal of a pulse code modulated signal, and a pattern signal and a frame signal generated by this pattern generation circuit. (ii) a frame synchronization circuit for a pulse code modulated signal transmitted from the transmission means; and a pattern detection circuit for detecting a pattern signal. The receiving means includes a circuit, and a setting switching means for switching settings according to a pattern signal detected by the pattern detection circuit.

In other words, the transmission method setting system of the present invention uses one multiframe out of n multiframes as a subframe within a range where forward protection of frame synchronization is maintained, and inserts transmission method setting data into this subframe. This is what I did.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples.

FIG. 1 shows a circuit configuration of a transmission method setting system according to an embodiment of the present invention.

The transmission method setting system includes a transmitting device 11 and a receiving device 12. Frame signal generation circuit 13 of transmitter 11
generates a frame signal 14 for frame synchronization of the primary group PCM (pulse code change m) signal. The frame signal 14 constitutes one multiframe with 12 bits.

For example, the signal “100011011100” (F
frameAlignment Signal and MultiframeAlignment Signal
al) is now output.

Setting data for changing the settings of the receiving device 12 by remote control is input to the pattern generating circuit 16 of the transmitting device 11 from the setting data input terminals 17-1 to 17-12.

The pattern generation circuit 16 is configured to output a subframe signal 18 in which a subframe synchronization bit and a check pit are added to the input setting data based on the frame signal 14 generated by the frame signal generation circuit 13.

The selector 19 is supplied with a PCM signal 21 created by a PCM device (not shown). Selector 19 is PCM
Frame signal generation circuit 13 for each frame of signal 21
The frame signal 14 generated is added one bit at a time and sent to the transmission path.

Furthermore, the selector 19 changes the frame signal 14 into the frame signal 14 by one multiframe every n (n indicates an integer) multiframe and sends the subframe signal 18 to the transmission path. The selector 19 receives the start signal 23 output from the start switch 22 and sends out the subframe signal 18.

The frame synchronization circuit 26 of the receiving device 12 of the remote station performs frame synchronization of the primary group PCM signal transmitted via the transmission line 27. The PCM signal 28 whose primary group has been synchronized by the frame synchronization circuit 26 is supplied to a signal processing section and a subframe synchronization circuit 29 (not shown). The subframe synchronization circuit 29 synchronizes the subframes and inputs them to the pattern detection circuit 31. The pattern detection circuit 31 separates the setting data added by the transmitting device 11 from the manually inputted signal, and supplies it to the terminals 32-1 to 32-12 of the setting switching section 32 in parallel. In the setting switching unit 32, settings are switched between the AMI code and the B8ZS code using a changeover switch (not shown) based on the supplied setting data D2.

The operation of the transmission method setting system configured as described above will be described next.

In general, frame synchronization, including multiframe synchronization,
Forward protection is performed to protect against code errors on the transmission path. That is, when one multi-frame is defined as one stage, it is determined that synchronization has been lost for the first time when synchronization cannot be detected in n stages in a row, and a hunting operation is started. However, 1
If only one of the stages is out of synchronization, it is not determined that the synchronization is out of synchronization, and the synchronization state is continued. In this embodiment, the forward protection of this synchronization circuit is used to change the transmission code of the receiving device to A.
Setting data for changing from MI code to B8ZS code is transmitted.

2 and 3 show the structure of the frame signal 14 and subframe signal 18 added to the PCM signal 21 by the selector 19.

In Figure 2, only the bit signals added to each frame are extracted, and the frame signal 14 indicated by "1F" is divided into 3 multi-frames and the subframe signal 18 indicated by "D".
1 multiframe is added repeatedly. Frame signal 14 "F" and subframe signal 18 "D" each constitute one multiframe with 12 bits. The frame signal generation circuit 13 outputs a signal "100011011100" shown in Table 4 of CCITT Recommendation G704 corresponding to each bit of one multiframe.

FIG. 3 shows the structure of the multiframe signal 18 output from the pattern generation circuit 16, in which each multiframe of subframe synchronization bit D1, setting data D2, and check bit D3 is output in order. As the subframe synchronization bit D+, a code string that is preset between the transmitting and receiving devices 11 and 12, which is different from the frame synchronization signal 14, is used. The setting data D2 is also stored in advance in the transmitting/receiving device 11.
, 12, and the setting data input terminals 17-1 to 1
It is input from 7-12. Check bit D is added to detect bit errors in setting data D2.

When the start signal 23 is input from the start switch 22, the selector 19 changes one multiframe out of every four multiframes into the frame signal 14 and sends the subframe signal 18 to the transmission line.

Subframe signal 18 is sent to the arrangement of FIG. Since this subframe signal 18 needs to be transmitted only when the line is opened, the selector 19 adds setting data to the PCM signal 21 and sends it out only during the initial setting when the start signal 23 is supplied.

The frame synchronization circuit 26 of the receiving device 12 of the remote station performs frame synchronization of the primary group PCM signal transmitted via the transmission line 27. The PCM signal 28 in which the primary group has been synchronized is supplied to a signal processing section and a subframe synchronization circuit 29 (not shown). The subframe synchronization circuit 29 detects the subframe synchronization bit D and performs subframe synchronization,
A PCM signal 28 is supplied to the pattern detection circuit. The pattern detection circuit 31 separates the setting data D2 from the supplied PCM signal 28, and outputs the setting data D2 to the terminals 32-1 to 3 of the setting switching section 32.
2-12 in parallel. In the setting switching section 32,
Based on the supplied setting data D2, the setting is switched from the AMI code to the B8ZS code by a changeover switch (not shown).

During active use after the transmission code has been changed by the initial settings, the selector 19 adds only the frame synchronization signal 14 to the PCM signal 21, and adds B12. Normal data transmission using S codes takes place.

In the embodiments described above, changing the transmission code has been explained, but by changing the contents of the setting data input from the setting data input terminal, the setting of the setting switching unit is switched to, for example, only a specific line of the receiving device 12 to be in a busy state. It is also possible.

〔Effect of the invention〕

As described above, according to the present invention, setting data such as transmission codes is transmitted using frame bits without causing synchronization forward protection to malfunction, so that settings can be automatically made without the operator having to go to a remote station. This makes it possible to operate the communication network more efficiently and reliably. Furthermore, since there is no need to allocate a special time slot to transmit the configuration data, the configuration data can be transmitted efficiently.

[Brief explanation of drawings]

The drawings are for explaining one embodiment of the present invention, of which Fig. 1 is a circuit configuration diagram of a transmission method setting system, and Fig. 2 is a circuit configuration diagram of a transmission method setting system.
The figure is an explanatory diagram for explaining the bit configuration of a frame signal and subframe signal added to a PCM signal, and FIG. 3 is an explanatory diagram for explaining the configuration of the subframe signal. 11... Transmitting device, 12... Receiving device, 13... Frame signal generation circuit, 16...
...Pattern generation circuit, 17-1 to 17-12...Setting data input terminal, 19...Selector, 26...Frame synchronization circuit, 29...・Subframe synchronization circuit,
31...Pattern detection circuit, 32...Setting switching unit. Director NEC Corporation

Claims (1)

[Scope of Claims] A pattern generation circuit that generates a predetermined pattern signal in synchronization with a frame signal of a pulse code modulated signal, and a pattern signal generated by this pattern generation circuit and the frame signal that are predetermined. a transmitting means comprising a frame signal switching circuit for transmitting the frame signals in sequence; a frame synchronization circuit for pulse code modulated signals transmitted from the transmitting means; a pattern detection circuit for detecting the pattern signal; and the pattern detection circuit. 1. A transmission method setting system comprising: a receiving means having a setting switching means for switching settings according to a pattern signal detected by the transmission method setting system.