JPS63233615A - Line switching method - Google Patents

Abstract

PURPOSE:To relieve the simultaneous fault of each carrier in a line in current use, by providing matrix switches at the sending terminal and the receiving terminal of a multiplex micro line, and connecting each carrier of the line in current use and a spare line. CONSTITUTION:The matrix switches 101 and 102 provided at the stages of a unipolar signal can select arbitrarily and connect mutually the carrier signal of each channel of the line in current use and that of the spare line at the sending and receiving terminals. Therefore, it is not necessary that a succeeding faulty channel waits the recovery of a preceding faulty channel in the simultaneous faults of different channels in current use with the same number of carriers like in a conventional line switching system for plural carriers in which the lines in current use having plural carriers are switched comprehensively to the spare lines, and the relief of a faulty line can be performed sufficiently, and the momentary disconnection ratio of the line can be improved.

Description

[Detailed Description of the Invention] [Table of Contents] Overview Industrial Application Fields Prior Art (Figures 11 and 2) Problems to be Solved by the Invention (Figure 13) Means for Solving the Problems (Fig. 1) Example of operation (Fig. 2 to Fig. 1θ) Effects of the invention [Summary] The transmitting end and the receiving end of a multiplex micro line that transmits information of each channel in a plurality of working lines and protection lines by a plurality of carriers. A matrix switch is provided at each end so that each carrier of the working line and the protection line can be arbitrarily connected, so that simultaneous failure of each carrier in the working line can be relieved. [Industrial Application Field] The present invention relates to a line switching system in a multiplex microwave transmission system, and in particular, in a line switching system for a multiplex microwave line that uses multiple carriers, a matrix switch is placed in the working line to relieve simultaneous carrier failures. It is related to the method.

In multiplex microwave transmission systems, it is becoming common to adopt a multilevel modulation method to increase line capacity and transmit the amount of information per channel using multiple carriers, but it is important to improve the reliability of data transmission. Therefore, it is required to improve the instantaneous line interruption rate more than in the past.

In such line switching equipment, a double switching method is generally adopted, and the carrier terminal equipment (carrier end) accompanying the switching
There are two methods: unipolar stage switching without momentary interruption to prevent synchronization, and bipolar stage switching for backing up device translations. The present invention relates to a method of unipolar stage switching without momentary interruption.

[Conventional technology]

FIG. 11 shows an example of a conventional line switching system, in which one channel and one carrier are used.

At the feeding end, channels 1 to 1 from the feeding end (not shown)
The bipolar signal of n is bipolar/unipolar (B-
U) It is converted into a unipolar signal via the converting sections 11 to In, and is multi-level modulated and transmitted via the transmission logic sections 21 to 2n.

At the receiving end, the signals of each channel are transmitted through the receiving logic section 31 to
3. is multilevel demodulated and reproduces a unipolar signal,
The signal is converted into a bipolar signal through bipolar (U-B) converters 41 to 4, and sent to the carrier end of each channel 1 to n (not shown).

In the event of a fault, the faulty channel at the sending end changes from the bipolar signal to the protection channel B- depending on the location of the fault.
The signal is switched to the U converter 1r+transmission logic unit 2r, or the unipolar signal is switched to the backup transmission path and transmitted, and the reception logic unit 3r of the backup channel is transmitted at the receiving end.
as a unipolar signal, or as a unipolar signal from the U-B converter 4r.
The signal is then switched to the original channel and sent out as a bipolar signal. The test signal is sent out as a bipolar signal from the sending end via the spare channel, and is detected as a bipolar signal at the receiving end.

FIG. n shows another example of the conventional line switching system, illustrating the case of one channel and two carriers.

The configuration in this case is almost the same as that in Figure 11, but
At the sending end, the signals of each channel 1 to n are divided into two signals in the BU converters 11 to 1n, and transmitted by two carriers via the transmitting logic sections 21 to 2n, respectively, and then to the receiving logic section 31 at the receiving end. ~3! The signals are demodulated into two signals through U-B converters 41 to 44, respectively, and reproduced as signals of channels 1 to n, respectively. The spare channel is also composed of two carriers, and the rotation switching is performed by switching the two carriers together.
The switching is performed in the same way as the switching for each channel in FIG.

Note that the configuration is similar when transmitting one channel of signals using three or more carriers.

In the method shown in FIG. 12, two carriers are used for one channel of information and the one channel band is divided into two, so that the influence of selective fading occurring within the band can be reduced. Band 1 by increasing the number of carriers
If f:a is increased, this effect will be greatly increased.

[Problem that the invention seeks to solve]

In the switching system shown in FIG. 11, only one carrier is used for one channel of information, so the influence of selective aging within the band is large. In addition, the switching system shown in Fig. 7 improves the aging resistance to some extent, but in the case of simultaneous failures of carriers with the same number in different channels, only the first channel is rescued.
Late-starting channels must wait to switch to backup channels until the faulty channel of the first-starter is recovered, leaving room for improvement in the line interruption rate.

FIG. 13 explains how to remedy a failure of carriers with the same number in the case of a one-channel two-carrier system. In the figure, (a) shows a case in which carriers 1 of channel Ion have simultaneous failures; channel 1, which is the first failure, is relieved, but channel n, which is the later failure, is not relieved until channel 1 is restored. Also(
b) shows a case where each carrier 2 of channel inn has simultaneous failures; similarly, only channel 1 with the earlier failure is relieved, and channel n with the later failure is not relieved.

As described above, in the conventional line switching system, there has been a problem that relief from instantaneous line interruption in the event of a failure is not sufficiently provided.

[Means for solving problems]

The present invention is intended to solve the problems of the prior art, and has the basic configuration shown in FIG. In multiple microcircuits each carrying a plurality of carriers, a matrix switch 101 .
102 T--The transmitting end and the receiving end are provided, and by controlling the transmitting end and the receiving end, switching between the working line and the protection line is performed without any interruption.

The matrix switches 101 and 102 arbitrarily select the signals of each carrier of each channel of the working line and the signals of each carrier of the protection line and connect them to each other.

[For production]

At the sending end and the receiving end, matrix switches provided in the unipolar signal stages can arbitrarily select and interconnect the signals of each carrier of each channel of the working line and the signals of each carrier of the protection line. Can be done. Therefore, in the case of a simultaneous failure of different working channels on carriers with the same number, as in the conventional multi-carrier line switching system in which working lines with multiple carriers are switched to protection lines all at once, the later failed channel is replaced by the earlier failed channel. There is no need to wait until the faulty channel is restored, and the faulty line can be repaired sufficiently, improving the line interruption rate.

〔Example〕

FIG. 2 shows nine embodiments of the present invention, illustrating the case of one channel and two carriers, and the same parts as in FIG. 11 are designated by the same numbers.

In the case of FIG. 2, line switching at the sending end and receiving end is performed by a bipolar switch 51 in the bipolar signal stage.
This is done by changing the unipolar switch 61.6z, which consists of a matrix switch in the unipolar signal stage, and switching the unipolar switch 61.6z, which is a matrix switch in the unipolar signal stage, so that each channel and each carrier can be changed independently. ing.

FIG. 3 shows an example of the configuration of a matrix switch, in which (a) shows the one at the sending end, 8W1 to 8W4.
is a switch. (b) shows the one at the receiving end, and SW5 to SW8 are switches.

That is, in FIG. 3(a), carrier 1. at the sending end constituting a certain channel. The signals of S2 can be independently switched and connected to carrier A1.42 of the protection channel. Similarly, in FIG. 3(b),
The signals on the carrier A1.42 of the spare channel at the receiving end are independently transmitted to the carrier A1.42 of the channel.
Connection can be made by switching to 42.

FIG. 4 explains the rescue operation when carriers with the same number fail when the system of the present invention is used, and shows the control of switch switching in the case of a failure in the carrier of the same number in two channels. This is what is shown.

In FIG. 4, (a) shows that at the sending end, carrier 41 of channel 1 is connected to carrier 1 of the spare channel via switch swi '6, and carrier I&1 of channel n is connected to carrier 42 of the spare channel via switch SW2. At the receiving end, the carrier 1 of the spare channel is connected to the carrier 41 of channel 1 through the switch swsf, and the carrier A2 is also connected to the carrier 41 of the channel 1 through the switch sws
A case is shown in which connection is made to carrier 1 of channel n via Wa.

FIG. 4(b) shows that at the sending end, carrier J161 of channel 1 is connected to carrier &2 of the spare channel via switch 8W2, and carrier 1 of channel n is connected to carrier A of the spare channel via switch 8W1.
1, and at the receiving end connect carrier 1 of the spare channel to channel 2 via switch 5 to carrier/I6.
1, and also the spare channel carrier 2t-
A case is shown in which connection is made to carrier A1 of channel n via switch A6.

Thus, according to the embodiment of FIG. 2, the channel number,
Simultaneous failure of two carriers can be relieved regardless of the carrier number.

In addition, in both cases of Fig. 4 (a) and (b), the sending end,
Switches located at corresponding positions on the receiving end shall be operated in conjunction with each other.

FIG. 5 shows an embodiment in the case of one channel and three carriers, in which the same parts as in FIG. 2 are indicated by the same numbers, and information of one channel is transmitted and received by three carriers. , a corresponding 3x3 matrix switch is provided at both the transmitting and receiving ends, and as in the case of Fig. 2, each channel and each carrier can be switched independently, and the channel number and carrier number can be switched independently. Regardless of the situation, simultaneous failures of up to three carriers can be relieved.

ga The same figure shows an embodiment in the case of t channels and 4 carriers, where the same parts as in FIG. Corresponding 4×4 i-trix switches are provided at both the transmitting and receiving ends, and simultaneous failures of up to 4 carriers can be relieved regardless of the carrier number, channel number, or carrier number.

FIG. 7 shows an example of the configuration of the switching system in the system of the present invention. In the figure, 7 is a sending end control section, and 8 is a receiving end control section.

Switching control in the switching system shown in FIG. 7 is performed by the following procedure.

■ Detection of line failure at the receiving end → Confirmation of non-use of spare channel → Sending command to switch unipolar switch at the sending end →
Unipolar switch and switch switching at the sending end → Sending switching response from the sending end → Receiving the sending end switching response at the receiving end → Switching the unipolar switch at the receiving end ■ Line failure recovery → At the receiving end Canceling the switching of the unipolar switch → Stopping the unipolar switch switching command for the sending end → Canceling the switching of the unipolar switch at the sending end ■ Detection of bipolar signal disconnection at the receiving end → Confirm non-use of spare channel No response for unipolar switch switching at the receiving end → Sending a bipolar switch switching command at the sending end → Switching the bipolar switch at the sending end → Switching response from the sending end → Switching the sending end at the receiving end Receiving a response → switching the receiving end bipolar switch ■ In the case of bipolar signal loss recovery, cancel the switching of the bipolar switch using the same procedure as ■ O In addition, in the case of the switching method using a matrix switch,
Since there is no correspondence between a faulty line and a unipolar switch for relieving it, it is necessary to add switch selection logic that allocates priority to the lowest numbered switch, for example.

Further, in FIG. 7, it is assumed that the switching command is transmitted from the receiving end control section 8 to the sending end control section 7 through a reverse line.

8 and 9 show configuration examples of the switching control system in the method of the present invention, in which FIG. 8 shows an example of the receiving end control section 8, and FIG. 9 shows an example of the sending end control section. 7 is shown as an example.

In FIG. 8, when a line failure signal is generated due to the detection of a line failure, if a test signal from the sending end is detected and a test signal detection signal is generated, the unipolar switching control unit 1
1 determines that the spare channel is not used and generates a unipolar switching signal.At the same time, a switching command is sent from the transmitting end switching command encoding unit, and the unipolar switch is switched at the transmitting end.

On the other hand, if the unipolar switching response signal indicating the switching response of the unipolar switch is not received within a certain period of time, the switching impossibility determination unit 13 determines that the unipolar switch cannot be switched, and the bipolar switching control unit 14 determines that the unipolar switch cannot be switched.
As a result, a bipolar switching signal is sent from the bipolar switching control 14, and a switching command is sent from the sending end switching command encoding unit 12, so that the bipolar switch is switched at the sending end. .

Further, when a visor signal disconnection detection signal is generated due to detection of a bipolar signal disconnection, and a test signal detection signal is being output, the bipolar switching control unit 14 determines that the spare channel is not used and generates a bipolar switching signal, This similarly causes the bipolar switch to be switched at the sending end.

On the other hand, if the bipolar switching response signal indicating the switching response of the bipolar switch is not received within a certain period of time, the switching impossibility determination unit 15 determines that the bipolar switch cannot be switched and displays this. do.

In FIG. 9, when a switching command is received from the receiving end,
The unipolar switching control section 17 or the bipolar switching control section 18 generates a unipolar switching signal or a bipolar switching signal to switch the unipolar switch or the bipolar switch.

When receiving a unipolar switching response signal indicating a switching response of a unipolar switch or a bipolar switching response signal indicating a switching response of a bipolar switch, the sending end switching response encoding unit 19 transmits a switching response signal.

In the case of matrix switching, the switch to be switched is selected in unipolar switch switching control and bipolar switch switching control at the receiving end. At this time, it is necessary to incorporate logic such as giving priority to the smallest number as described above.

FIG. 10 is an illustration of how to reduce the instantaneous line interruption rate by the line switching system of the present invention, and shows a comparison between the case of 1 carrier and the case of 4 carriers. Although an improvement effect of about 1.5 times can be obtained, if an individual switching method is used in which switching is performed individually between corresponding carrier numbers, an improvement of about 1.5 times can be obtained. Furthermore, if a matrix switching method that arbitrarily switches between different carrier numbers is used, an improvement effect of about 1.5 times can be obtained. Therefore, if the 1-carrier method and the 4-carrier matrix switching method are compared, the improvement effect is about 9 times. It has been shown that the improvement effect can be obtained.

〔Effect of the invention〕

As explained above, according to the line switching system of the present invention, the transmitting end and the receiving end are provided with a matrix switch for line switching, and each channel and each carrier can be switched independently. As a result, the correspondence between the carrier of the working channel and the carrier of the backup channel can be arbitrarily made, making it possible to recover from line failures in the most flexible manner and improving the rate of momentary line interruptions. .

[Brief explanation of drawings]

Fig. 1 shows the basic configuration of the present invention, Fig. 2 shows an embodiment of the invention, Fig. 3 shows an example of the structure of a matrix switch, and Fig. 4 shows carriers with the same number. A diagram illustrating relief in the event of a failure. Figure 5 is a diagram showing an embodiment in the case of 1 channel and 3 carriers. Figure 6 is a diagram showing an embodiment in the case of 1 channel and 4 carriers. Figure 7 is a diagram showing the method of the present invention. 8 is a diagram showing an example of the configuration of the receiving end control section, FIG. 9 is a diagram showing an example of the configuration of the sending end control section, and FIG. 10 is a diagram showing an example of the configuration of the switching system according to the method of the present invention. Figure 11 is a diagram showing an example of a conventional line switching system, Figure N is a diagram showing another example of a conventional line switching system, and Figure 13 is a diagram showing an example of a failure in a carrier with the same number. It is a figure explaining relief in. 11-1. ．． 1r...Bipolar/unipolar (B-
U) Conversion stand 21-2. , 2r...Transmission logic units 31-3m, 3r...Reception logic units 41-4. ,4
r...unipolar/bipolar (U-B) conversion table 51
．． 5x...bipolar switch 6! , 6x... Unipolar switch 7... Sending end control section 8... Receiving end control section 11... Unipolar switching control section ■... Sending end switching response encoding section

Claims (1)

[Claims] In a line switching system in a multiplex micro line that has a plurality of channels of working lines and protection lines, and in which information of each channel is transmitted by a plurality of carriers, each carrier of each channel of the working line The transmitting end and the receiving end are provided with matrix switches (101, 102) that arbitrarily select and interconnect the signals of the carriers of the protection line and the signals of each carrier of the protection line, and by the control of the matrix switches (101, 102). A line switching method characterized by switching between a working line and a protection line without any interruption.