JP3106962B2 - Data transmission path identification information generation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to the identification information generating system of the data transmission path, have a backup transmission line one to particular working path plurality of, information via the backup transmission line
When information is transmitted, the route of the transmission path followed by the information
The present invention relates to an identification information generation system for a data transmission path that generates identification information indicating the following .

[0002]

2. Description of the Related Art FIG. 2 is an overall configuration diagram of a synchronous terminal apparatus including a data transmission path identification information generating system.

[0003] A synchronous terminal device is a device for generating and terminating a transmission signal using a clock that is frequency-synchronized with a reference clock of a transmission system.

[0004] This synchronous terminal device is a terminal used in a transmission system having one spare transmission line for a plurality of active transmission lines in order to secure a communication line when a failure occurs in the device or the transmission line. Device.

As shown in FIG. 1, the transmission system is, for example,
Four working transmission paths A to D, one protection transmission path E, high-speed interfaces (HSIF) 500 to 507 provided in the respective working transmission paths A to D, and a high-speed interface provided in the protection transmission path E Interface (HSIF) 508, 509
And switching units 510 to 517 provided in the protection and working transmission lines A to E, respectively, and selection units 520 to 527 provided in the protection and working transmission lines A to E, respectively.

In this transmission system, for example, it is assumed that an active transmission line B is used. If the transmission path B is normal, the information is transmitted to the switching unit 511 and the high-speed interface 5.
02, the current transmission path B, the high-speed interface 503, and the selection unit 525.

On the other hand, when a failure occurs in the active transmission line B, the information is transmitted to the switching unit 511, the selection units 521 and 520, the high-speed interface 508, the standby transmission line E, the high-speed interface 509, the switching units 514, 515, and the selection unit 525. Is transmitted via

Next, an outline of the operation of the transmission system will be described. First, an in-apparatus reference clock / frame pulse generation unit (not shown) generates an in-apparatus clock / frame pulse synchronized with a reference clock of the transmission system, and each unit in the apparatus (in this description, each of the switching units 510 to 517 ). Are distributed in the same frame.

In each of the switching units 510 to 517, a signal inputted from the upstream is read out in the buffer memory by the distributed clock / frame pulse in the apparatus (so-called clock / frame pulse replacement).

Thus, even if the signal from the upstream is interrupted, the clock / frame pulse can be transmitted to the downstream switching unit, and the spread of the signal interruption can be minimized.

When a plurality of active transmission lines are provided as in this transmission system, a plurality of switching units are required.

Since the switching of the clock / frame pulse described above is performed in each of the switching units 510 to 517, each time the signal passes through one switching unit, a signal delay corresponding to the capacity of the buffer memory and the signal circuit is generated.

That is, when four switching units are provided as shown in FIG. 2, the signal delay increases from the switching units 514 to 517. Further, the frame phase of the input signal from the upstream switching unit of each of the switching units 514 to 517 with respect to the in-device frame is different for each switching unit.

The switching units 510 to 517 delay the readout frame pulse from the buffer memory in accordance with the frame phase of the input signal in the apparatus frame in order to reduce the size of the buffer memory.

Since the input frame phases at the switching units 510 to 517 are different as described above, in order to determine the delay amount of the frame pulse read from the buffer memory, it is necessary to recognize the order of the switching unit. There is a need to.

For this reason, the identification information of the number of the switching unit is inserted into the signal and transmitted to the downstream switching unit, and the downstream switching unit determines from the received identification information the number of the switching unit of the own switching unit. By recognizing, the delay amount of the frame pulse delay unit is determined.

Next, the configuration and operation of the switching unit will be described. FIG. 3 is a configuration diagram of an example of a conventional switching unit.

FIG. 1 shows a switching unit 514 of the active transmission line A and a switching unit 515 of the active transmission line B as an example.

Although the switching units 514 to 517 shown in FIG. 1 have the same configuration, the switching unit 515 will be mainly described.

The switching unit 515 extracts the identification information from the information input from the upstream (switching unit 514) and holds the identification information, and determines whether or not the identified information is continuously received for a certain number of frames. Information monitoring unit 205 for monitoring
When the identified information is received continuously for a certain number of frames, the protection circuit 206 in which the identified information is stored as correct information, and a clock, a frame pulse, and information from the upstream are input, and the information is input by the clock. And a frame pulse delay unit for delaying the frame pulse in the self-switching unit 515 to the optimum read phase in the buffer memory 203 based on the identification information obtained by the protection circuit 206. 207, an identification information generation unit 208 that generates identification information to be sent downstream (switching unit 516) based on the identification information from the identification information holding unit 204, and an identification information generation unit 208 that generates information read from the buffer memory 203. Identification information insertion unit 202 for inserting the identified identification information, and output from the identification information insertion unit 202 A branching unit 220 for branching and outputting the obtained information, and a selecting unit 525 to which one of the branching outputs of the branching unit 220 is input, and the other branching output of the branching unit 220 is provided in a downstream (switching unit 516) buffer. Output to memory.

The clock and frame pulse to each of the switching units 514 to 517 are supplied to an internal reference clock / frame pulse generation unit 5 provided outside the switching units 514 to 517.
30 and the frame pulse delay unit (2
07, 107, etc.).

That is, when information is read from the buffer memory 203, clock / frame pulse switching is performed.

Next, the operation will be described. The identification information holding unit 204 extracts identification information from the information input from the branch unit 120 of the switching unit 514. The identification information monitoring unit 205 checks whether the same identification information is received continuously for a certain number of frames.

When the identification information is received continuously for a certain number of frames, the identification information monitoring unit 205 determines that the identification information is correct and stores it in the protection circuit 206.

On the other hand, when a certain number of frames are not received continuously, the identification information monitoring unit 205 determines that the identification information is erroneous information and does not store it in the protection circuit 206.

Information is stored in the buffer memory 203 by the branching unit 120 of the switching unit 514 using the clock and frame pulse of the switching unit 514.

On the other hand, the in-device reference clock / frame pulse is input to the frame pulse delay unit 207 from the in-device reference clock / frame pulse generation unit 530, and the clock / frame pulse includes the identification read out from the protection circuit 206. A predetermined delay is given based on the information, and the information is read from the buffer memory 203 with the frame pulse after the delay.

The identification information generation unit 208 includes the identification information holding unit 2
04 based on the identification information read from the
Generate identification information to be sent to 6). Then, the generated identification information is inserted into the information read from the buffer memory 203 by the identification information
Output to

Then, the information from the branching unit 220 is sent to the selecting unit 525 and the downstream (switching unit 516).

Here, if the upstream (switching unit 514) is removed, there is no input clock / frame pulse.
Identification information cannot be confirmed. At this time, since the identification information immediately before being removed is held in the identification information holding unit 204, the identification information is read out from the identification information holding unit 204 and transmitted to the downstream switching unit 516.

In this case, even if the switching unit 514 is inserted again, since the identification information based on the input identification information before the removal to the downstream switching unit is transmitted, the identification information does not change by the insertion.

Incidentally, this type of transmission line switching technique is disclosed in Japanese Patent Application Laid-Open Nos. 4-33438 and 61-146.
No. 038.

[0033]

However, depending on the method of removal, the contact and peeling of the connector may be repeated temporarily, which may cause noise on the signal line and take in erroneous information. In some cases, the transfer of the clock / frame pulse may not be performed normally.

FIG. 4 is a timing chart of frame pulses and information input to the switching unit, and FIG. 5 is a timing chart of frame pulses and information input to the switching unit when the upstream switching unit is removed.

FIG. 4 is a diagram of counting from the input of the frame pulse.
This indicates that the identification information is inserted at the bit position.

FIG. 5 shows the relationship between the frame pulse signal entering the switching unit 515 from the switching unit 514 when the switching unit 514 is removed and the identification information in the information. Noise P when the switching unit 514 is removed after a bit appears in the frame pulse signal, and this is erroneously input to the switching unit 515 as a frame pulse.

For example, if such a situation occurs in a system in which five switching units are connected, it is assumed that the identification information is defined as a 4-bit value as shown in FIGS. Will be described.

For each of the five switching units, “0000” is identification information indicating the switching unit 1, “0001” is identification information indicating the switching unit 2, “0010” is identification information indicating the switching unit 3, and “0” is identification information indicating the switching unit 3.
The identification information obtained by adding “1” to the identification information from the upstream, such as “011” as the identification information indicating the switching unit 4 and “0100” as the identification information indicating the switching unit 5, as the identification information to the downstream switching unit. When switching unit 2 is pulled out while sending,
The part of the data “xxxxxx” that is not the identification information is “0”
If it is any of the ten types of “101” to “1110”, even if “1” is added by the identification information generation unit in the switching unit 2 and output to the downstream switching unit 3, the identification information of the switching unit 3 The monitoring unit does not read it, so that an incorrect frame pulse delay setting is not performed.

However, if the part of the data "xxx" which is not the identification information by chance is "0010", for example, the identification information generation unit in the switching unit 2 adds "1". It is output to the switching unit 3 as “0011”, and the switching unit 3
In such a case, the switching unit 4 is accepted as identification information indicating the switching unit 4, and there is a problem that the frame pulse delay setting as the switching unit 4 is erroneously performed even though the switching unit 3 is used.

Accordingly, an object of the present invention is to provide a data transmission path identification information generation system capable of preventing erroneous frame pulse delay setting in a downstream switching section due to removal of an upstream switching section. is there.

[0041]

The present invention in order to solve the above problems SUMMARY OF THE INVENTION are active transmission line a plurality of have a backup transmission line one to the case where the information via the backup transmission line is transmitted
Generates identification information indicating the route of the transmission path followed by the information.
In the identification information generation system of the data transmission path to be formed, each working transmission line has a switching unit that switches the transmission line to its own transmission line or the backup transmission line, the switching unit,
Identification information extraction means for extracting identification information indicating a data transmission path from information input via the spare transmission path and another switching means, and identification information storage means for storing identification information of the immediately preceding information; And identification information selection means for selecting and outputting the identification information from the identification information extraction means or the identification information storage means based on the information as to whether or not the upstream switching means is implemented. Features.

[0042]

According to the present invention, the identification information immediately before the removal of the upstream switching unit is extracted by the identification information extracting means, and the identification information extracted immediately before the identification information is stored in the identification information storing means. , And one of the identification information extracted by the identification information extraction means and the identification information stored in the identification information storage means is selectively output by the identification information selection means.

On the other hand, information as to whether or not the upstream switching means is mounted is input to the identification information selecting means, and the identification information selecting means is not provided with the upstream switching means (that is, when the upstream switching means is removed). If the upstream switching means is mounted (that is, if the upstream switching means is not removed), the identification information stored in the identification information storage means is selectively output. The selected identification information is output.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram of an example of a data transmission path identification information generation system according to the present invention. In FIG. 1, a switching unit 101 is a conventional switching unit 51.
The switching unit 201 corresponds to the switching unit 515 of the conventional example.

Although the configuration of the switching unit 101 and the switching unit 201 is the same as in the conventional example, the switching unit 201 will be mainly described.

The switching unit 201 differs from the conventional switching unit 515 in that a selection unit 209 is added to the conventional switching unit 515 (the switching unit 101 corresponds to the selection unit 109). For other configurations, the conventional switching unit 515
Therefore, the same reference numerals are given to the respective components, and the description will be omitted.

The selection section 209 receives both the identification information from the protection circuit 206 and the identification information from the identification information holding section 204.

On the other hand, a control signal Q for controlling the selection section 209 is input to the selection section 209 from outside. This control signal Q is transmitted to an upstream switching unit (the switching unit 10
1 is an upstream switching unit. ) Is a high-level signal Q1, for example, and a low-level signal Q2 if the upstream switching unit is not mounted, that is, is removed.

Then, the identification information selected by the selection unit 209 is input to the identification information generation unit 208.

The identification information stored in the identification information holding unit 204 is the identification information extracted from the latest information input from the upstream switching unit 101, and the identification information stored in the protection circuit 206 is the latest. This is the identification information input immediately before the identification information. Because, the protection circuit 206 includes:
This is because the identification information is stored only when the identification information monitoring unit 205 determines that the same desired identification information is continuously received for a certain number of frames.

Therefore, if the switching unit 101 is removed and a noise P as shown in FIG. 5 occurs b bits after the frame pulse, the switching unit 201 erroneously recognizes the noise P as a frame pulse. As a result, incorrect identification information is stored in the identification information holding unit 204.

On the other hand, the protection circuit 206 stores the identification information immediately before the identification information, that is, the identification information before the switching unit 101 is removed, and the identification information is correct information. Therefore, when the switching unit 101 is removed, identification information may be extracted from the protection circuit 206.

That is, when the upstream switching unit is mounted, the high-level control signal Q1 is input to the selection unit 209, and the selection unit 209 selects the identification information from the identification information holding unit 204 and selects the identification information generation unit. 208.

On the other hand, when the upstream switching unit is removed, a low-level control signal Q2 is input to the selection unit 209, and the selection unit 209 selects the identification information from the protection circuit 206 and sends the identification information to the identification information generation unit 208. Output.

Note that, based on the identification information from the protection circuit 206, the frame pulse
03, the phase synchronization of the frame pulse read out of the information (that is, the clock and the frame pulse are switched), and the identification information generated by the identification information generation unit 208 is converted by the identification information insertion unit 202 into the information. Inserted into
The transmission to the downstream switching unit is the same as in the conventional example.

[0056]

According to the present invention, there is provided an identification information generating system for a data transmission path in a transmission system having one spare transmission path for a plurality of active transmission paths, wherein each of the current transmission paths is either a self transmission path or A switching unit for switching a transmission line to the backup transmission line, wherein the switching unit extracts identification information indicating a data transmission path from information input via the standby transmission line and another switching unit; Means,
An identification information storage unit in which the identification information of the immediately preceding information is stored, and information as to whether or not the upstream switching unit is mounted, are input, and based on the information, the identification information extraction unit or the identification information storage unit And identification information selecting means for selecting and outputting the identification information, so that when the upstream switching means is removed, the information is received by the identification information selecting means, and the identification information selecting means receives the identification information based on the information. Correct identification information can be obtained by selecting the immediately preceding identification information stored in the storage means.

Therefore, it is possible to prevent erroneous setting of the frame pulse delay due to removal of the upstream switching means.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an example of a data transmission path identification information generation system according to the present invention.

FIG. 2 is an overall configuration diagram of a synchronous terminal device including a data transmission path identification information generation system.

FIG. 3 is a configuration diagram of an example of a conventional switching unit.

FIG. 4 is a timing chart of a frame pulse and information input to a switching unit.

FIG. 5 is a timing chart of frame pulses and information input to the switching unit when the upstream switching unit is removed.

[Explanation of symbols]

 Reference Signs List 201 switching unit 202 identification information insertion unit 203 buffer memory 204 identification information holding unit 205 identification information monitoring unit 206 protection circuit 207 frame pulse delay unit A to D working transmission line E standby transmission line

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04Q 3/52 H04Q 11/00-11/08 H04L 1/00 H04L 1/08-1/24 H04B 1 / 74

Claims (4)

(57) [Claims] 1. A place for active transmission line a plurality of have a backup transmission line one hand, information via the backup transmission line is transmitted
In this case, identification information indicating the route of the transmission path followed by the information is used.
An identification information generation system for a data transmission path to be generated, wherein each of the active transmission lines has a switching unit that switches a transmission line to its own transmission line or the backup transmission line. Identification information extracting means for extracting identification information indicating a data transmission path from information input through the switching means, identification information storage means for storing identification information of the immediately preceding information, and upstream switching means A data transmission path, comprising: inputting information as to whether or not the identification information has been input, and selecting and outputting the identification information from the identification information extracting means or the identification information storage means based on the information. Identification information generation system. 2. The identification information selection means, when receiving information indicating that the upstream switching means is not mounted, selects and outputs the identification information from the identification information storage means, and the upstream switching means is mounted. 2. The data transmission path identification information generating system according to claim 1, wherein said identification information extracting means selects and outputs said identification information when said information is received. 3. The system according to claim 1, further comprising a transfer means for transferring a clock and a frame pulse input together with information from upstream based on the identification information extracted from said identification information storage means. An identification information generation system for a data transmission path described in the above. 4. An identification information insertion unit for generating new identification information based on the identification information output from the identification information selection unit, inserting the identification information into information from the upstream, and outputting the information to the downstream switching unit. 4. The data transmission path identification information generating system according to claim 1, further comprising a unit.