JPH07123247B2 - Digital data transmission method - Google Patents

Description

The present invention relates to a digital data transmission method in a digital communication network.

〔Overview〕

The present invention relates to a digital data transmission method in a digital communication network in which a control signal and a data signal are embedded in an envelope on a channel-by-channel basis and multiplexed and transmitted in parallel, using a plurality of envelopes transmitted on the same transmission line. By constructing frames and transmitting a multi-frame pattern that identifies the relative transmission line delay between individual envelopes using the status bits in a specific envelope in this multi-frame, the same transmission line with different relative delays is transmitted. The signal is divided and transmitted.

[Conventional technology]

In a digital communication network, data signals and control signals from terminals are added with frame bits by a multiplexer, time-division multiplexed, and transmitted in units of envelopes.

FIG. 3 is a diagram showing this envelope. F is the status bit framing bit, D ₁ to D ₆ is the data bits, S is sampled control signal.

When transmitting between stations, 20 channels for envelopes for 2.4 kb / s data, 10 channels for envelopes for 4.8 kb / s data, 5 channels for envelopes for 9.6 kb / s data. Are multiplexed and transmitted to digital 0th order group signals of 64 kb / s.

FIG. 4 is a diagram for explaining the frame structure of the 0th-order transmission line. FIG. 5 is a diagram for explaining a frame pattern used in the 0th-order transmission line.

FIG. 4 (b) shows a 64 kb / s subgroup frame structure. Here, the envelopes for 2.4 kb / s data shown in FIGS. 4 (c) and (d) are multiplexed in 20 channels. Has become. F'in FIGS. 4 (c) and 4 (d) is CCITT shown in FIG. 5 when it is multiplexed on the 0th-order transmission line.
Replaced with the standard X.50 frame pattern. Therefore, this F'is an empty bit. FIG. 4 (a) shows a bit array of each channel to be multiplexed, and F is a framing bit. An X.50 frame pattern corresponding to the frame number shown in FIG. 5 is inserted into this framing F. In addition, A of FIG. 5 is a game alarm bit.

[Problems to be solved by the invention]

In this way, when transmitting on the 0th-order group transmission line using the X.50 frame pattern, the terminal speed is 2.4 kb / s,
Only 4.8 kb / s and 9.6 kb / s. Especially, at the terminal speeds of 4.8 kb / s and 9.6 kb / s, the same zero-order group envelope is 4.
Two must be used for transmission at 8 kb / s and four for 9.6 kb / s.

If we use two different 0th order envelopes, we get 4.8kb /
When the data of s is transmitted, if the delays of the 0th-order transmission lines are different, the arrival times of the envelopes are different, so that the continuity of the data cannot be maintained.

FIG. 6 is a diagram for explaining the drawbacks of the conventional digital data transmission system. 4.8 kb / s data transmitted by FIG. 6 (s), FIGS. 6 (t) and (u) are envelopes sent to the 0th order transmission line with different relative delays, FIG. 6 (t ′),
(U ') is the envelope transmitted using the transmission path, and FIG. 6 (s') is the data resulting from the transmission. Here, a case where (u ') is one envelope larger than (t') for different relative delays of the 0th order group transmission line is shown. Thus, it can be seen that the data (s) to be transmitted and the result (s') transmitted have different bit arrangements and that normal transmission is not performed.

If the same next group transmission line must be used when transmitting the same data, if the 2.4 kb / s signal is accommodated in 19 channels in the 0th group transmission line, the remaining envelope is 1 It becomes individual and can accommodate only 2.4 kb / s signal. Furthermore, even when there are a plurality of 0th-order group transmission lines, even if the number of extra envelopes is commensurate with the transmission of 4.8 kb / s, it is not possible to perform 4.8 kb / s transmission using this.

It is an object of the present invention to provide a digital data transmission method which makes it possible to divide and transmit the same data by using a plurality of transmission lines having different relative delays.

[Means for solving problems]

The present invention is a digital data transmission method for constructing an envelope of a control signal and a data signal for each channel of a low-speed channel signal, multiplexing the envelope in accordance with a CCITT Recommendation X.50 multiplexing sequence, and transmitting it as a high-speed signal form. In a digital data transmission method for transmitting a signal of the same channel in parallel by combining a plurality of transmission lines, a plurality of n envelopes transmitted through the one transmission line are combined to form a multiframe, and among the n envelopes, A bit of a multi-frame pattern for identifying the above-mentioned multi-frame is inserted in the status bit in which the control signal is inserted for a specific envelope, and the data is transmitted on each transmission line. At the receiving side, this is transmitted for each transmission line. Detects a multi-frame pattern and delays transmission between multiple transmission lines. Characterized by reorganizing the data transmitted by correcting the transmission delay difference to recognize the difference.

[Work]

Generally, the relative delay difference of the 0th-order group transmission line is finite, and it is several envelopes when converted into the number of envelopes.

In the present invention, for example, a multiframe having twice the relative delay difference is assembled by using the status bit in the envelope, and the control information and the multiframe information are transmitted. After detecting the relative delay difference of a plurality of envelopes from this multi-frame information and correcting the relative delay difference, the divided transmitted data is reorganized to use a plurality of transmission paths with different relative delay differences. Enabled digital data transmission.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an apparatus for realizing the digital data transmission method of the present invention.

FIG. 2 is a diagram for explaining a signal transmission process of the method of the present invention.

In FIG. 1, a data signal (s) and a control signal RS
Are input to envelope creating circuits 101 and 102 which multiplex those signals into envelopes. Envelopes (t) assembled by the envelope creating circuits 101 and 102,
(U) is input to the multi-frame creation circuits 103 and 104, respectively, and becomes multi-frame signals (v) and (w) having 8 envelopes as one multi-frame, and sent to the 0th-order group transmission lines 105 and 106, respectively. . This 0th group transmission line 10
The multi-frame signals (v ') and (w') transmitted through 5 and 106 are respectively stored in the elastic memory.
It is input to 107, 108 and multi-frame synchronization detection circuits 109, 110. The multi-frame signals (t ′) and (u ′) read out from the elastic memories 107 and 108 with the same multi-frame number are input to the envelope decomposing circuits 111 and 112, respectively, where the data signals (e) and It is separated into (f) and control signals (g) and (h).

The reference signal (x) output from the multi-frame synchronization detection circuit 109 is input to the elastic memories 107 and 108, and the multi-frame information (y) and (z) output from the multi-frame synchronization detection circuits 109 and 110, respectively. ) Is
It is inputted to the elastic memories 107 and 108 and the envelope decomposing circuits 111 and 112, respectively.

The data signals (e) and (f) are sent to the data assembling circuit 113.
The data signal (s') that has been input and transmitted is assembled and output. Also, control signals (g) and (h)
Is connected to an OR gate 114, and is output as a control signal CD from the OR gate 114.

The frame structure of the 0th-order transmission lines 105 and 106 is the frame structure shown in FIG. 4 and uses the frame pattern shown in FIG. Therefore, the 0th-order group transmission lines 105 and 106
Input and the envelope bit position at the output of _{(F ', D 1 ~D 6} , S) is known.

In the envelope generation circuits 101 and 102, the data signal (s)
Is a control signal RS and an envelope (t) every 6 bits,
(U) is assembled. The envelopes (t) and (u) thus assembled are used in the multiframe generation circuits 103 and 104.
Then, 8 envelopes are set to 1 multiframe, and a multiframe pattern (an alternating pattern of 1/0 in this case) is inserted into the S bit once every 4 times, and multiframe signals (v) and (w) Become. The multi-frame signals (v) and (w) are transmitted through the 0th-order group transmission paths 105 and 106, respectively, so that the multi-frame signals (v ′) and
(W '). In this embodiment, the 0th-order group transmission line 106 is 0
This is a transmission line having a delay of 24 envelopes larger than that of the next-group transmission line 105.

In the multi-frame synchronization detection circuits 109 and 110, 1 /
The 0 alternating pattern is found to detect the multi-frame number, and the data is written in the elastic memories 107 and 108 according to the multi-frame number.

The reading from the elastic memories 107 and 108 is performed in order from the multiframe number 1 as the center (multiframe number 5) of the multiframe of the multiframe signal (v ′) by the reference signal (x), respectively.

The multi-frame signals (t ') and (u') read out in such a manner that the multi-frame numbers match with each other are data signals (e) and (f) and a control signal (g) in the envelope decomposing circuits 111 and 112. , (H). The separated data signals (e) and (f) are converted into data signals (e) and (f) in units of 6 bits of data in the envelope by the data assembling circuit 113.
The data signals (s) before transmission are rearranged in the order of (f) and are restored and output as data signals (s ′).

On the other hand, in the envelope disassembling circuits 111 and 112, the multiframe information (y) and (z) are used to remove the multiframe pattern, and the bits omitted by the removal of this multiframe pattern are filled in by the immediately preceding S to obtain the control signal. (G),
Output (h). The control signals (g) and (h) are 2
It is a signal transmitted by being divided into the transmission paths of the system, and is output as the control signal CD by taking the logical sum of the signals by the OR gate 114. That is, the control signal RS on the transmitting side is reconstructed as the control signal CD on the receiving side.

〔The invention's effect〕

As described above, the present invention transmits the relative phase difference information of the transmission path together with the control signal, and the receiving side extracts the relative phase difference information from this multiframe to correct the relative delay difference, thereby Data transmission can be performed by dividing the same signal using different transmission paths.

That is, by transmitting the same data in parallel,
There is an effect that a plurality of 0th-order transmission lines can be effectively used and an economical data transmission network can be constructed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an apparatus for realizing the digital data transmission method of the present invention. FIG. 2 is a diagram for explaining a signal transmission process according to the method of the present invention. FIG. 3 is an explanatory diagram of the envelope. FIG. 4 is a view for explaining the frame structure of the 0th-order transmission line. FIG. 5 is a diagram for explaining a frame pattern used in the 0th-order transmission line. FIG. 6 is a diagram for explaining the drawbacks of the conventional digital data transmission system. 101, 102 ... Envelope creation circuit, 103, 104 ... Multi-frame creation circuit, 105, 106 ... Zero-order transmission line, 10
7, 108 ... Elastic memory, 109, 110 ... Multi-frame sync detection circuit, 111, 112 ... Envelope decomposition circuit, 113 ... Data assembling circuit.

Claims (2)

[Claims] 1. A digital data transmission method for constructing an envelope of a control signal and a data signal for each channel of a low-speed channel signal, multiplexing the envelope according to a CCITT Recommendation X.50 multiplexing sequence, and transmitting it as a high-speed signal form. Then, in a digital data transmission method in which a plurality of transmission lines are combined and signals of the same channel are transmitted in parallel, a plurality of n envelopes transmitted through the one transmission line are combined into a multiframe, and among these n envelopes, For the specific envelope of, the control signal is inserted into the status bit, the bit of the multi-frame pattern for identifying the above multi-frame is inserted and transmitted on each transmission line, and on the receiving side, for each transmission line This multi-frame pattern is detected and transmitted between multiple transmission lines. Digital data transmission wherein the reorganizing transmitted by correcting the transmission delay difference recognizes delay difference data. 2. The digital data transmission method according to claim 1, wherein the multi-frame is composed of at least twice as many envelopes as the relative delay difference between the transmission lines.