JPH01149544A - System for stuff synchronizing communication - Google Patents

Abstract

PURPOSE:To add a subsignal such as an alarm signal without lowering the transmitting efficiency of data by utilizing the data at the time of inserting a stuff among frame data, multiplexing the subsignal and transmitting it. CONSTITUTION:At a transmitting side, in response to a stuff insertion instructing signal at the time of reading the frame data from a channel board 1, the subsignal is inserted into the data at the time of inserting the stuff of the data by a stuff control circuit 2. By a multiplexing part 3, according to the stuff insertion instructing signal, and stuff designations of the data of respective channels are executed in the frame data. At a receiving side, the frame data received by a separating circuit 4 are separated for respective channels. By the contents of the stuff designation bits of the separated frame data, the subsignal contained in the position of the data at the time of inserting the stuff is detected by a subsignal detecting circuit 5. Thus, the subsignal can be transmitted in being inserted into an old data position not to be used at the time of inserting the stuff, and the subsignal can be increased without deleting the data.

Description

[Detailed Description of the Invention] [Summary] The purpose of this invention is to add sub-signals such as alarm signals without reducing data transmission efficiency with respect to a stuff synchronous communication method that performs carrier multiplexing and separation in the stuff synchronous method. On the transmitting side, in response to a stuff insertion instruction signal from the channel board when frame data is read from the channel board, a stuffing control circuit inserts a sub-signal into the data when stuffing the data, and the multiplexer inserts the stuffing into the data. Specify the data stuffing for each channel according to the insertion instruction signal,
On the receiving side, a separation circuit separates the received data for each channel, and a sub-signal detection circuit detects the sub-signal included in the position of the data at the time of stuff insertion from the contents of the stuff specification of the separated data. has.

[Industrial application field]

The present invention relates to a stuff synchronous communication system, and more particularly to a stuff synchronous communication system that performs transport multiplexing and demultiplexing in a stuff synchronous system.

Currently, 3 45Mbps data are bundled to 140Mbp.
Data transmission that is multiplexed with s data is carried out between stations using dedicated lines, but maintenance signals as sub-signals are multiplexed into the data to monitor the status of each station. , and an increase in this maintenance signal is becoming necessary.

[Prior Art] The well-known stuff synchronization method is a method that brings each asynchronous digital signal into a synchronous relationship by appropriately inserting/deleting extra codes in the code string of multiple digital signals with different clock frequencies. As shown in Figure 6, the data from the data terminal is sent to each channel board C.
Store in H3 and transport multiplexing device! Multiplexing is performed in view of the fact that when the fMUX is used to bundle and transmit the data, the bit rate stored in the channel board CH3 and the bit rate read out to the multiplexer MUX, that is, the bit rate sent out from the multiplexer MUX, are different. After synchronizing the stuff in the device MUX (inserting stuff) and sending it to the transmission line, the receiving side separates the input data for each channel, stores each channel data in each channel board CHR, and reverses the data from the sending side. The data is sent to the terminal while being destuffed.

At this time, on the transmitting side, the monitoring signal AL from the monitoring bag ffM is
M is further multiplexed in a multiplexer MUX.

The format of the frame used in this method is the seventh
This frame format is as shown in the figure. This frame format is a multiplexed version of 3 channels, and the frame is divided into 6 sets, each of which has 159 bits, for a total of 95 bits.
It consists of 4 bits. Among these, the first set is a frame synchronization pattern and data “1” for frame detection.
to "49" (each data is further composed of D1 to D), and the No.
” to rloIJ, and the second set consists of three stuff specification bits sr+, sat, 32 bits and data “1
The first set consists of three stuff specification bits S21% S2 R150, an alarm bit X for maintenance only (SEND), a parity bit P, an auxiliary bit, and data r154J to "203". and the Vth set has three stuff specification bits S
41, s4g, S43 and data r204J to r255J
and the Vth set consists of three stuff specification bits S S I % S % 2, Ss! and data when inserting stuff #D1 to #D, and data "256" to r3
06J.

FIG. 8 shows a transmitting side transport multiplexing device that performs data transmission using such a frame format. In the figure, 1 is a channel board provided for each channel and serving as a buffer for temporarily storing data. The memory 11 compares the phase between the input and output signals of the memory 11, and when the phase of the output data and the phase of the input data match, it is determined that the read operation has caught up with the write operation, and a predetermined output signal is output. and a phase comparator 12 for generating the signal.

Further, reference numeral 20 denotes a read clock generation section 21 for reading data stored in the memory 11, a control clock generation section 22 for generating a read clock that is the basis of this read clock generation section 21, and a read clock generation section 22 for generating a read clock when stuffing is inserted. This stuff control circuit includes a stuff control section 23 that controls the read clock from the section 21. Note that the control clock generator 22 may be omitted and the read clock generator 21 may generate the control clock. 3 is a multiplexing unit that multiplexes all channels, frame patterns, etc. using each channel data from the memory in each channel board and the stuffing control signal (phase comparison result) from the stuffing control unit 23; The bit rate of output data from 11 is 45Mbp
s, the bit rate of the output data from the multiplexer 3 is 140 Mbps.

FIG. 9 shows the separation circuit 4 on the receiving side for the transmitting side in FIG.
This separation circuit 4 includes a frame synchronization section 41 that detects a frame synchronization pattern, a separation section 42 that separates data for each channel, and a separation section 42 that is interconnected with the frame synchronization section 41 and outputs various control clocks. a destuff control unit 44 that generates a destuff identification status signal from the frame clock from the control clock generation unit 43 and the channel data separated by the separation unit 42; It is composed of a write clock generation section 45 that generates a write clock based on the status signal and a control clock signal from a control clock generation section 43 (corresponding to the control clock signal in FIG. 8), and outputs data from the separation section 42. is written to the subsequent channel board (not shown) by the write clock from the write clock generator 45.

Next, the operation of the apparatus shown in FIGS. 8 and 9 will be explained along with the time charts shown in FIGS. 10 and 11, respectively. Note that the symbols attached to these time charts correspond to the symbols shown in FIGS. 8 and 9, respectively.

The data written in the memory 11 is read out by the read clock (2) from the read clock generator 21. This read clock (2) is a clock generated from the control clock generator 22 (corresponding to the waveform on the right side of the clock (2) in FIG. 10) as is, unless stuffing is performed. Therefore, the data read out by this read clock becomes as shown on the right side of the data signal ■ in FIG. In addition, the clock ■
The tooth extraction part is set in advance by the control clock generator 22.

In this way, data ■ is read from the memory 11, multiplexed with other channel data in the multiplexer 3, and transmitted to the receiving side, but since the read clock of the memory 11 is faster than the write clock, it is left as is. If you do so, the read operation will catch up with the write operation and you will not be able to read. In order to avoid this, the phase comparator 12 compares the phases of the input data and output data of the memory 11, generates a phase difference signal, and sends it to the stuff controller 23.
send to In response to this, the stuff control unit 23 generates a signal that becomes "1" when the phase difference signal decreases, and clock
The tooth extraction cuts the next clock of the part (the tooth extraction is predetermined at one clock next to the part) and temporarily prohibits reading data from the memory 11. Then, the signal from the phase comparator 12 to the stuff control unit 23 is sent to the multiplexing unit 3 after adjusting the timing to correspond to the part of the clock ■ such as the signal ■. Along with data multiplexing, as shown in Figure 6, the stuff designation is uniformly set to ``l'' or ``0'' for the channel (channel CHI in the figure).At this time, when stuffing is inserted, the data is , data in Figure 10 ■
As shown on the left side of , since no new data is read out, data D (hereinafter referred to as #D1) is transmitted with the old data left as is.

On the receiving side, after frame synchronization is performed on the received high-order group data ■ by the frame synchronization unit 41,
Synchronize with various control clocks @, [phase] generated in step 3. The data ■ is separated into low-order group data @ of each channel by the separation unit 42.

In addition, the destuffing control unit 44 also controls the stuffing designation bits (Sll to SS in channel CHI,
) is "1" or "0°°," and if there are many "1"s, the output is "l", and 10"
A destuff identification status signal (2) is output with a value of 10'' when there are more cases.

This majority vote originally means that the stuff specification bits are the same °1
” or “0°”,
Since it can change depending on the state of the transmission path, the one with the largest number is determined to be "true".

The destuff identification status signal [phase] determined in this way is sent to the write clock generator 45 along with the signal @.
is input to the channel board and output as the write clock [phase] for the channel board. In this case, stuff specification bit S
If the majority vote of ++ to SS+ is "1°", it is identified as destuffing, and the write clock is in a state where one extra tooth is missing, as shown in the signal ■.This signal @(
The left part of Figure 11) is the readout clock in Figure 10.
It can be seen that it corresponds to the left side of .

[Problem that the invention seeks to solve]

In such a staff synchronous communication system, if an attempt is made to multiplex the alarm bit by adding it to the maintenance-only bit First, in that case, there was a problem that the transmission efficiency decreased.

Therefore, an object of the present invention is to realize a staff synchronous communication system that can add sub-signals such as alarm signals without reducing data transmission efficiency.

[Means for solving problems]

In the present invention, we have focused on the fact that the data #D1 to #D at the time of stuff insertion in the frame format shown in FIG. This method attempts to multiplex and transmit sub-signals using data #D1 to #D during stuff insertion.

FIG. 1 shows a conceptual diagram of a staff synchronous communication system according to the present invention to achieve the above object.
When frame data is read from channel board l, the stuff control circuit 2 inserts a sub-signal into the stuff data in response to the channel board 1 to 9 stuff insertion indicator code, and the multiplexer 3 inserts a sub-signal into the data. Stuffing the data of each channel is performed according to the stuffing insertion instruction signal. Also, on the receiving side, the separation circuit 4 separates the received data for each channel, and the stuffing is performed based on the contents of the stuffing designation bit of the separated data. The sub signal included in the position of the time data is detected by the sub signal detection circuit 5.

[For production]

In the stuff synchronous communication system according to the present invention shown in FIG. 1, the channel board 1 reads input frame data in response to a read signal from the stuff control circuit 2, and the multiplexer 3 multiplexes each channel data.

When the frequencies of the write clock and read clock of the channel board 1 are different, and the read catches up with the write, the stuff control circuit 2 generates a stuff insertion instruction signal based on the phase comparison signal from the channel board 1. In response, a sub-signal such as an alarm signal is inserted into the frame data read from the channel board 1 at a predetermined position of stuff insertion data and sent to the multiplexer 3. The multiplexer 3 specifies stuffing in the frame data in accordance with the stuffing insertion instruction signal described above.

On the receiving side, a separation circuit 4 separates the received frame data for each channel. Then, the contents of the stuff specification bits of the separated frame data (whether there are many “1” or “0”
The sub-signal detection circuit 5 detects the sub-signal included in the data position when stuffing is inserted.

As a result, it is possible to insert and transmit a sub-signal in an old data position that is not used during stuff insertion, and by detecting this on the receiving side, it is possible to increase the sub-signal without deleting the data itself.

〔Example〕

Hereinafter, an embodiment of the staff synchronous communication system according to the present invention will be described.

2 and 3 respectively show a transmitting side and a receiving side used as an embodiment of the staff synchronous communication system according to the present invention, and FIGS. 4 is a time chart showing the operation of the circuit shown in FIG. 3; Note that for convenience of explanation, only one channel is shown.

First, in FIG. 2, as the stuff control circuit 2,
In addition to the conventional read clock generation section 21, stuff control section 23, and control clock generation section 22, a sub signal such as an alarm signal is used as an input signal, and the sub signal sampling clock from the control clock generation section 22 is used as a clock. The stuff insertion instruction signal (
An AND gate 26 between the phase comparison result signal (matched to the position of the data at the time of stuff insertion), an AND gate 27 between the inverted signal of this AND gate 26 and the output data of the memory 11, and the output of this AND gate 27. It includes the output of AND gate 25 and OR gate 2B. still,
The output of the OR gate 2B is input to the multiplexer 3 as channel CHI data.

In addition, in FIG. 3, the conventional frame synchronization unit 4
1, the separation unit 42, the control clock generation unit 43, the destuffing control unit 44, and the write clock generation unit 45, as well as the data sampling clock at the time of stuff insertion from the control clock generation unit 43 and the destuffing control unit. 44, and a D-type flip-flop 47 that uses the output of the AND gate 46 as a clock signal and uses the channel frame data output from the separation section 42 as an input signal to generate a sub-signal. A sub-signal detection circuit 5 is provided.

Next, the operation on the transmitting side will be explained with reference to FIGS. 2 and 4. Note that the waveforms 1 to 2 shown in FIG. 4 are similar to the waveforms shown in FIG. 10, and their explanation will be omitted.

As shown in the figure, the sub-signal sampling clock ■ generated by the control clock generating section 22 is generated at a position corresponding to the position in the frame of data #D1 (see FIG. 7) at the time of stuff insertion, and the sub-signal sampling clock ■ is generated by flip-flopping the sub-signal data ■. P24
Obtain data ■ by sampling. Therefore, the AND output of this data ■ and the sub signal sampling clock ■
is sent to the OR gate 28 as RZ (Return-to-Zero) sub-signal data. In addition, by ANDing the sub signal sampling clock ■ and the stuff insertion instruction signal output from the stuff control unit 23 in the AND gate 26, the output of the AND gate 27 becomes data ■, and at this time, the output of the AND gate 27 becomes data ■. Since the data corresponding to the data position of signal data ■ is removed, OR gate 2B
The output ■ is inputted to the multiplexer 3 with sub signal data ■ inserted as shown.

As is well known, in the multiplexing section 3, when multiplexing the data (2) of each channel, the stuff insertion instruction signal (2) from the stuff control section 23 is simultaneously input, and if this stuff insertion instruction is received, For example, all the stuff designation bits in the frame format shown in FIG. 7 are set to "1". Therefore, for this purpose, although not shown, a buffer is provided in the multiplexer 3 to store one frame and wait for a stuff insertion instruction.

On the receiving side shown in FIGS. 3 and 5, the signals ■ to [
11, but the stuff insertion data (#Dl
) sampling clock @ and destuff control unit 44
A sub-signal sampling clock [phase] is obtained by logically ANDing the output of the destuff identification status signal 146 with the destuff identification status signal 2, which is used as a clock and the destuff identification status signal 2 is used as an input signal. 47 generates a sub-signal output [phase] which can be used by subsequent equipment (not shown) to monitor alarm conditions on the transmitting side.

In the above description of the embodiment, explanation has been given for l channels, but it goes without saying that the same operation is performed for other channels as well.

□ [Effects of the Invention] As described above, according to the stuff synchronous communication method of the present invention, the sub-signal is inserted using the stuff insertion data in the frame data, so there is no need to newly provide a dedicated bit for the sub-signal. For example, if the frame length is 954, it is possible to transmit sub signals and maintain a certain transmission efficiency.
bit, the main signal bit rate is 139.264Mbp
When s, the stuffing rate is 0.5343 and the stuffing cycle is 7.
7.997KHz, maximum sub signal transmission speed is 11.99
1Hz.

[Brief explanation of the drawing]

FIG. 1 is a block diagram conceptually showing a staff synchronous communication method according to the present invention, FIG. 2 is a block diagram showing a transmitting side system of the staff synchronous communication method according to the present invention, and FIG. FIG. 4 is a block diagram showing the system on the receiving side of the staff synchronous communication method according to the present invention, FIG. 4 is a time chart diagram for explaining the operation on the transmitting side of the staff synchronous communication method according to the present invention, and FIG. A time chart diagram for explaining the operation on the receiving side of such a staff synchronous communication system, FIG. 6 is a system diagram of a general staff synchronous communication system including a multiplexed alarm signal, and FIG. 7 is an example of the present invention and a conventional example. Figure 18 is a block diagram showing the transmitting side system of the conventional stuff synchronous communication method, and Figure 9 is the receiving side of the conventional stuff synchronous communication method. A block diagram showing the system of FIG. 10 is a time chart diagram for explaining the operation of the transmitting side of the conventional staff synchronous communication method, and FIG. 11 is a time chart diagram for explaining the operation of the receiving side of the conventional staff synchronous communication method. This is a time chart diagram. In FIG. 1, ■... Channel board, 2... Stuff control circuit, 3... Multiplexer, 4... Separation circuit, 5... Sub-signal detection circuit. In the figures, the same reference numerals indicate the same or corresponding parts. r＋＋＋＋＋＋＋＋＋＋＋＋＋＋＋＋＋＋（F＋＋＋
H - ++++ - +++++++++++ + J anti -Fig. 2 Figure 3 Fig.

Claims (2)

[Claims] (1) On the transmitting side, frame data is sent to the channel board (
1) In response to a stuff insertion instruction signal from the channel board (1) when reading from the data, the stuff control circuit (2) inserts a sub signal into the data when stuffing the data, and the multiplexer (3) inserts a sub signal into the data. Stuffing the data of each channel is performed according to the stuffing instruction signal, and on the receiving side, the separation circuit (4) separates the received data for each channel, and inserts the stuffing based on the stuffing specification contents of the separated data. A stuff synchronous communication system characterized in that a sub signal included in the position of time data is detected by a sub signal detection circuit (5). (2) The staff synchronous communication system according to claim 1, wherein the sub-signal is an alarm signal.