JPH0332255A - Service signal transmission system - Google Patents

Abstract

PURPOSE:To send a service signal without changing the transmission speed and disturbing the code rule by converting a block code using a specific n-bit as the unit and a service signal into a block code in the unit of relevant n-bit, sending the result and applying inverse conversion to the block code to extract the service signal. CONSTITUTION:The system is provided with a sender side code conversion means 2 converting a block code in the unit of specific m-bit into a block code in the unit of n-bit among block codes in the unit of plural n-bit in response to the state of a service signal and a receiver side code conversion means 3 applying inverse conversion to the sender side code conversion means 2. Then the block code in the unit of specific m-bit and the service signal are fed to the sender side code conversion means 2, in which they are converted into a block code in the unit of relevant n-bit and the result is sent, the receiver side code conversion means 3 applies the inverse conversion to the code to extract the service signal. Thus, the service signal is sent without changing the transmission speed and disturbing te code rule.

Description

[Detailed Description of the Invention] (Summary) Regarding a service signal transmission method used in a digital transmission system, an object of the present invention is to enable service signals to be transmitted without changing the transmission speed or disturbing the coding rules. In a system that transmits signals using mBnB codes, when transmitting a service signal, the transmitting side assigns a block code of a plurality of n bits to a block code of a specific m bit, and transmits the service signal. Transmitting side code conversion means for converting the specific m-bit block code into a block code of one n bit among the plurality of n-bit block codes in accordance with the state; and a receiving side code converting means for performing a conversion operation opposite to that of the transmitting side code converting means on the receiving side. In addition, the code is converted into a block code in units of corresponding n bits and sent out, and the code conversion means on the receiving side performs inverse conversion to extract the service signal.

[Industrial application field]

The present invention relates to a service signal transmission method used in a digital transmission system.

In digital transmission systems, service signals (for example, bits for order wire signal monitoring and control) must be transmitted in order to transmit the main signal, but at this time, the transmission speed must not be changed and the coding rules must not be disturbed. It is necessary to be able to transmit service signals.

[Prior Art] First, when a signal (for example, a binary code) that has been digitized in the encoding part is sent to a transmission path, it is converted into a transmission code that is compatible with the transmission medium and transmission system, and then transmitted. There is a need to.

For example, in the case of an optical fiber transmission system, a binary symbol is used, but removing the DC component from the binary symbol, or even using a continuous pattern of "o" or "1" or a specific pattern, will cause problems. Request to be able to transmit data without using Bit 5 sequence
Various code configurations have been studied to realize den t (BSI), but one of them is
There is an mBnB code.

mBnB code (m, n are positive integers, m < n) is a block code (hereinafter referred to as mB
signal) into a block code (hereinafter abbreviated as nB signal) in units of n bits.
Among the 20 combinations of nB signals, those with a mark rate close to 2, and
A signal train with good BSI properties is constructed by using a pattern with a small number of consecutive O'' or 1n.

Next, FIG. 4 is a block diagram of a conventional example. The operation shown in FIG. 2 will be explained below.

In FIG. 4(a), the speed conversion section 11 increases the transmission speed of the input signal to create a gap, and the service signal insertion section 12 inserts the service signal into the gap and sends it out as an output signal to the transmission path.

Further, in FIG. 4(b), a service signal insertion section 13 inserts a service signal into an empty time slot provided in advance in the human signal and sends it out to the transmission path. In this case, the transmission speed of the output signal remains unchanged.

[Problem to be solved by the invention]

In the case of FIG. 4(a), an extra circuit such as a speed conversion section is required. In addition, in the case of Figure 4(b), if an error is detected at reception (jl, +1) using the nBmB code, a code that does not match the mBnB code is inserted, so the mBnB code error detection circuit is used. become unable.

That is, there is a problem in that the transmission rate must be changed or the coding rule must be disturbed in order to transmit the service signal.

An object of the present invention is to enable service signals to be transmitted without changing the transmission rate or disturbing the coding rules.

[Means to solve problems]

FIG. 1 shows a block diagram of the principle of the present invention.

In the figure, 2 assigns a plurality of n-bit block codes to a specific m-bit block code, corresponding to the state of the service signal.

3 is a transmitting side code converting means for converting the block code in units of the specific m bits into a block code in units of one n bits among the plurality of block codes in units of n bits; This is a receiving side code converting means that performs a conversion operation opposite to that of the receiving side code converting means.

Then, the specific block code in units of m bits and the service signal are added to the code conversion means on the transmitting side to convert into a block code in units of n bits and sent out, and the code conversion means on the reception side converts the block code and service signal into a corresponding block code in units of n bits. Perform reverse conversion to extract the service signal.

[Effect]

Here, as mentioned above, there are 2'' mB multiplied signal patterns,
There are 2'' patterns of the nB signal, and since 2''<2'', not all 22'' patterns are used.

Therefore, in the present invention, two types of n-bit buttons are assigned to patterns that appear relatively frequently (hereinafter referred to as @ constant patterns) among the m focus patterns of the mB multiplied signal. For example, 5.n that pattern. , n, the service signal is l
” is n.Use the pattern, “0゛′ is n,
By using patterns, service signals can be transmitted as information.

Furthermore, since the above specific pattern appears at an arbitrary time position, the service signal will be sampled and transmitted asynchronously. However, since no speed conversion is performed, service signals can be transmitted without changing the transmission speed or disturbing the coding rules.

[Embodiment] FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is an explanatory diagram of the operation of FIG. 2.

Here, the serial/parallel converter 21. Clock extractor 22.
3 frequency divider 23. ROM 24. Phase comparator 25. Voltage controlled oscillator 26, 4 frequency divider 27. The parallel/serial converter 28 is a component of the transmitting side code conversion means 2.

Also, the serial/parallel converter 31. 1 Kotoku extractor 32° 4 frequency divider 33. ROM 34. Phase comparator 35. Voltage controlled oscillator 36.3 Frequency divider 37. Parallel/serial converter 38. The WAD synchronization circuit 39 represents a component of the reception (if, IJ code conversion means 3).

First, m=3. A pattern is defined with n=4. 3
The B signal has eight patterns, but four are the transmission signals.
Since the B signal has 16 patterns.

Among these patterns, those with mark rate close to 2 and “Il
Select a pattern with few consecutive + or 0'' and decide as follows.

3B signal 4B signal (Original signal) (Transmission signal) 001 0011 01.0 0101 100 1001 011 0110 101 1010 iio tio.

111 1, 110 Alternate use 00I 000 0111 Alternate use 000 Here, among the above 3B signal patterns, olo has a higher occurrence frequency and is used for transmitting the service signal.

That is, when transmitting a service signal of 1°, 010-3
B signal is converted to 4B signal of 0101 and used, but when transmitting service signal °゛0'', 3B signal of oro is converted to 1
4B signals of 101 and 0010 are used alternately. Therefore.

If the 3B signal contains 010, then a service signal is superimposed and transmitted.

Since this code does not disturb the sign rule, the following RDS (Ru
There is no problem in detecting errors such as ning Di (abbreviation for H4tal Sum). Also, for example, the reason why 1101 and 0010 are used alternately is that the mark rate of both signals is 50%.
However, by using them alternately, the
This is because the numbers of '' become equal and the average mark rate becomes 50%.

Furthermore, RDS calculates the cumulative number by setting 1" to +1 and "0°' to -1. If there is no error, this value will be within a certain range, but if this value is outside the range, an error has occurred. It is thought that there are.

Now, the operation of FIG. 2 will be explained with reference to FIG.

(1) Transmitting side (see Figures 2(a) and 3(a)) First, convert the conversion table for converting the above 3B signal into 48 signals to R.
Although I have to write it to OM 24.

In order to perform the actual conversion operation, as shown in FIG.
This is a 6-person, 6-output, 7-conversion table for the signals and disparity signals sp and p.

Here, 2 For example, in case of IH, 1110 or 0001
The signal that instructs which pattern to use is the disparity signal, the P column is the disparity signal for 111 or 000, and the s1] column is the 010 signal for the service signal "'0" U. This is the disparity signal of

Note that *^ and *8 in FIG. 3(a) are inverted codes of A and II, but they are binary codes.

Next, we will explain the operation shown in Figure 2.
Assume that table a) has been written.

Now, the input 3B signal is applied to the serial/parallel converter 21 and converted into parallel signals of 3B1 to 3B3.

At this time, using the clock extracted from the 3B signal by the clock extractor 22 and the frequency-divided clock obtained by dividing this clock by 3 by the frequency divider 23, the 3B signal is input to the serial/parallel converter 23.
The B signal is input and output.

Now, if 3B1 to 3B3 are 010, it can be used to transmit the Zabis signal as described above, so it is 0 as the 2-service signal S.
”, sp is B, P is 8, and ROM 24 is input manually.The internal conversion table outputs 48 signals as 1, for example 1101., and the output side SP as *BP and 8 as P.Therefore, 411 signals are parallel / After being serially converted by the serial converter 28, it is sent out to the transmission line as a 4B signal, and the output side *B, II is returned to the input side.

Incidentally, after the output of the voltage controlled oscillator 26 is divided into 4 by the 4-frequency divider 27, the phases of the above-mentioned 3-frequency divider output and the d-divider output are compared by the 5-phase comparator 25 so that they match. The oscillation frequency of the voltage controlled oscillator 26 is controlled to synchronize input and output data.

Here, when the primary 311 signal is the old O, when the service signal "0P" is input again, the input terminal sp is *B, so 001O is sent out as a 4B signal, and the output side SP becomes H. , is returned to the input side.

However, when the service signal is "I", it is 0 as a 48 signal.
101 is sent to the parallel/serial converter↓, but since this pattern is not sent out alternately, 8 on the output side SP is returned as is as the input end SP.

Incidentally, the case where the 3B signal is ] and IL 000 is also similar to the above. In addition, FIG. 3 (aJ) indicates that "'arbitrary'" becomes "0" or "°1".

(2) Receiving side (see Figures 2(b) and 3(b)) The manually generated 411 signal is applied to the clock extractor 32 to extract the clock, and using this clock, the 4B signal is serial/ Although the parallel converter 31 is manually operated, synchronization is achieved by the word synchronization circuit 39.

2. For example, check whether the IB signal from an arbitrary position of the input signal matches a predetermined conversion rule. If it does not match, shift it by 1 pixel and check. Synchronization is maintained stably by performing forward protection and backward protection.

And then it was synchronized. After the II signal is converted from 4 inches to 464, it is input to the ROM and the 3B signal and S signal are extracted using the conversion table shown in FIG. 3(b). Series signal-S3
It is converted into and released.

Furthermore, as shown in the column S in Figure 3(b), the 1B signal is output while maintaining the previous state, but the one sent when the 311 signal 3 is 010 is taken as a service signal. Out/Se'bai. Note that 1 phase comparator 35. A voltage controlled oscillator 36 and a frequency divider 37 synchronize input and output data.

That is, the service signal can be superimposed by only partially changing the sign rule as described above, no extra circuit is required, and the sign rule is not disturbed.

(Effects of the Invention) As described in detail below, the present invention has the advantage that service signals can be transmitted without changing the transmission rate or disturbing the coding rules.

[Brief Description of the Drawings] Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of an embodiment of the present invention, Fig. 3 is an explanatory diagram of the operation of Fig. 2, and Fig. 4 is a diagram of the conventional example. A block diagram is shown. 5 HeP 0shi

Claims (1)

[Claims] An mBnB code (m
, n is a positive integer, and m < n). When transmitting a service signal, the transmitting side is required to input multiple n bits into a block code with a specific m bit as a unit. Allocating a block code as a unit, and assigning a block code in units of the specific m bits in units of one n bits among the plurality of block codes in units of n bits in accordance with the state of the service signal. A transmitting side code converting means (2) for converting into a block code with the specific m A block code in units of bits and a service signal are added to the transmitting side code converting means to convert into a corresponding block code in units of n bits and sent out, and the receiving side code converting means inversely converts the code to a service signal. A service signal transmission method characterized by extracting .