JPS59224954A - Digital trunk redundancy constituting system - Google Patents

Abstract

PURPOSE:To prevent remarkable reduction in traffic capacity due to the fault of a digital trunk or the like by substituting a digital trunk test equipment for a spare digital trunk. CONSTITUTION:If any part of a trunk 3 is faulty, test line drawing switch sections 33, 34 are activated to lead test wires of the trunk 3 into a device 4. All channels of incoming side L1 of a transmission line 2 in the device 4 are connected to a time division switch 5A through a receiving section 41 and a highway selector section 45. Then in testing, only the test channel is connected to a transmission section 44 through highway selector sections 45, 48. Further signals of all the channels are transmitted to an outgoing side L2 of the transmission line 2 through the highway selector section 46 via a time division switch 5B and via the transmission section 42. The receiving section 41 and the transmission section 42 of the device 4 plays a role of the faulty trunk 3 as a substitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to conversion between bipolar signals and unipolar signals and code conversion in a time division switch.

Regarding digital trunks with functions such as frame synchronization, multi-frame synchronization, elastic memory, failure detection, signal extraction, and signal insertion, etc., this relates to a digital trunk redundancy configuration method for minimizing the reduction in traffic capacity due to failures, etc. It is.

[Background of the invention]

Regarding digital trunks, the transmission path handles multiplexed signal transmission, so once a failure occurs, the impact will be large and the traffic capacity of the entire digital trunk may be significantly reduced. .

Therefore, one or a few spare digital trunks are provided for a large number of normally used digital trunks, and the regularly used one is switched to the spare one in case of a failure.
A redundant configuration method (so-called n+1
(Redundant configuration method) etc. have been required for a long time.

However, in order to install a backup digital trunk as described above and switch from a faulty regular trunk to a backup one, the transmission path is multiplexed and bipolar signal formation is required, so the switching requires technology. It was technically complex and costly, and it was difficult to maintain reliability.

In particular, when handling bipolar signals of 2,048 Mb/s, there are technical issues such as switching connections to backup digital trunks using coaxial cables.

This is economically difficult to realize, and a so-called n+ redundant configuration system has not been realized.

[Purpose of the invention]

The purpose of the present invention is to overcome the above-mentioned technical difficulties, to replace the digital trunk test equipment originally required in a time division switch as a backup digital trunk, and to minimize the reduction in traffic capacity due to digital trunk failures. The purpose of the present invention is to provide an economical digital trunk redundancy configuration system that can

[Summary of the invention]

The configuration of the digital trunk redundant configuration system according to the present invention is such that each digital trunk is connected to the transmission path of the receiving section and the transmitting section by separating the connection to the transmission path from the receiving section input side, the transmitting section output side, and the transmission path. The upstream side and the downstream side are used as test lines so that they can be pulled out separately, and it also has two sets of the same receiver and transmitter as the above digital trunk, and each of the above digital trunks When fault information is sent from a digital trunk in a time-division switch equipped with a digital trunk test equipment that can extract and insert signals related to the digital trunk test by connecting multiple test lines, A device that operates the test line pull-out switch section of the digital trunk to draw the test line into the digital trunk test equipment, and controls and processes one set of receiving section and transmitting section to operate as a backup substitute for the digital trunk. It is.

Note that it is also possible to perform a test on the digital trunk after preliminary switching of the digital trunk to a digital trunk testing device as a backup substitute.

If a failure indication is sent from a digital trunk and the digital trunk is not immediately switched to or connected to the digital trunk testing equipment as a substitute for the backup digital trunk, the digital trunk is tested with the digital trunk testing equipment mentioned above, and then the digital trunk is tested. The digital trunk test device may be used as a substitute for a backup digital trunk in case of a faulty one.

Generally speaking, there are more failures in transmission lines than in digital trunks, so even if preliminary switching is performed for digital trunks, each line (channel) will fail due to a failure in the transmission line.
This is effective in preventing the inconvenience of being unable to open the road.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a relay system diagram of an embodiment of the digital trunk redundant configuration system according to the present invention, FIG. 2 is a block diagram of an embodiment of the digital trunk and the test equipment, and FIG. 3 is a flowchart of the same. It is.

Here, 1 is a telephone (installation), 2 is a transmission path consisting of each upstream side (LL) and downstream side (L2), 3 is a digital trunk (DIC), 31.32 is its reception unit (R), and transmission part (S), 33.34 is the test wire pull-out switch part (S)
W), 4 is a digital trunk test equipment (DTTE),
41.42 and 43.44 are two pairs (two sets) of a receiving section (R) and a transmitting section (S), and these two sets insert and extract test call data into a specific test channel. What is required for this purpose, 45.46 and 47.48, are the corresponding highway selector units (SEL), where the above test data insertion and extraction are actually performed, and where the general Call.

49 is a test line switching unit (EX), 5 is a time division switch (TDSW), consisting of an uplink switch 5A and a downlink switch 5B; 6 is a time division switch for selecting channels for test calls; This is a control device (CONT) that controls and processes the entire divisional exchange.

In addition, each of the above-mentioned receiving sections 31, 41.43 and each transmitting section 32, 42.44 have the same function.

Further, within the digital trunk testing device 4, each receiving section 41.43 and each transmitting section 42.44 are cross-connected through corresponding highway selectors 45-48.

First, as shown in FIGS. 1 and 2, each test line TL of each digital trunk 3 is connected to a digital trunk test device 4 that is to be used as a substitute for a backup digital trunk. Digital trunk 3 (+1 to 4) = n)
If any of them (for example, +n) has a fault, operate the test line lead-in switch section 33, 34 as shown in the figure, and connect the transmission line 2 (+n) and digital trunk 3.
(sn) test line TL is drawn into the digital trunk test device 4.

In the digital trunk test equipment 4, the transmission line 2 (
+n), all channels on the upstream side (Ll) are connected to the receiving section 41.
Time division switch 5A through highway selector section 45
, and the audio signal is distributed to, for example, the telephone 1. Incidentally, during a test, only the test channel is connected to the transmitting section 44 through the highway selector sections 45 and 48.

Further, for example, signals of all channels from the telephone 1 and others pass through the highway selector section 46 via the time division switch 5B, enter the transmitting section 42, and then are sent out to the downstream side (L2) of the transmission path 2.

Incidentally, during a test, the transmitting section 42 will transmit both the general call and the test call, since both are selected by the highway selector section 46.

In this way, the digital trunk test device 4 has its receiving section 41 . The transmitting unit 42 can perform exactly the same function as a substitute for the digital trunk 3 (≠n), which has suffered from various failures. However, the receiving section 43. The transmitter 44 is completely unused.

Next, based on FIG. 3, a digital trunk testing device 4 is installed to replace the faulty digital trunk 3
This section explains the procedure for switching to .

This control processing is carried out by the control device 6, but in the following explanation, it will be assumed that preliminary switching is performed after testing the faulty digital trunk 3. Even in the case where backup switching is performed at the same time as a fault occurs and the digital trunk 3 is tested thereafter, the basics of control and processing remain the same, so a description thereof will be omitted.

One digital trunk 3 (hereinafter referred to as DIC)
If a continuous failure occurs, after blocking that DIC,
A test is performed using the digital trunk test equipment 4 (hereinafter referred to as DTTE).

If the DIC is normal as a result of the test, it means that there is a fault in the transmission line, so switching to DTTE as a standby substitute is not performed, and information indicating that there is a fault in the transmission line is displayed/reported.

If there is an abnormality in the DIC, the DIC failure information is displayed and reported, and then preliminary switching is performed.

In the preliminary switching, first, the DTTE is blocked and the hardware is switched. Hardware switching is a failure DI
This is achieved by switching the switch in C to connect the transmission line 2 and DTTE.

After switching the hardware, wait until the switching becomes stable and check whether there is any abnormality in the DTTE. If there is an abnormality, the hardware switching is restored and a DTTE test is performed. If there is a failure in the DTTE as a result of the test, information to that effect will be displayed and reported. If normal, DT
The TE is unblocked and the process ends. In these cases, switching is unlikely to be performed.

If there is no abnormality in the DTTE after switching, the software is switched.

In this embodiment, all programs other than programs that directly control hardware are assigned logical trunk terminal numbers (hereinafter referred to as L P
It's called N. ) is being processed. In addition, even in a program that directly controls hardware, LP
From N to physical trunk terminal number (hereinafter referred to as PN)
Processing is performed by converting to .

Therefore, the LPN-PN conversion table and P N
- Software switching can be performed simply by rewriting the T, PN conversion table. Furthermore, since switching is performed with the DIC blocked, there is no need to switch the communication path within the exchange.

The rewritten data will be used in the event of Phase 1 restart (suspending the previous key use and making gold bias a new regular use, (11) which generally takes about 15 seconds). In order to rescue the active call, the call is transferred to the backup system. However, since this data is important for the exchange, the file memory is not rewritten. Regarding this point, if there is still a failure after the system restarts in phase 2 (resuming from system failure), there is no problem because switching will be automatically performed.

In this embodiment, the switching is performed after the DIC is blocked in order to avoid the complicated process of switching the communication path.
- By switching the communication path (switching the time division switch) immediately before switching the hardware, it is possible to perform the switching while the call is in progress without being blocked.

〔Effect of the invention〕

As described above in detail, according to the present invention, when one DIC has a failure, generally 24 or 30 lines (channels) become out of service, but this time is spent as DIC test time, transmission line switching time, Since it is possible to use only the backup switching synchronization pull-in time (12), it is not only possible to prevent a significant drop in traffic capacity in the event of a DIC failure, but also it is possible to use DTTE as a substitute for the backup DIC. There is no need to install an extra DIC, and the efficiency of DTTE usage is increased, resulting in remarkable effects on improving the reliability, economy, maintainability, and serviceability of the time division switch.

[Brief explanation of drawings]

FIG. 1 is a relay system diagram of an embodiment of the digital trunk redundant configuration system according to the present invention, FIG. 2 is a block diagram of an embodiment of the digital trunk and the test equipment, and FIG. 3 is a flowchart of the same. It is. DESCRIPTION OF SYMBOLS 1... Telephone, 2... Transmission line, 3... Digital trunk, 31... Receiving part, 32... Transmitting part, 33
．． 34...Test line drawer switch section, 4...Digital track/retest device, 41.43...Receiving section, 42
．． 44... Transmission section, 45-48... Highway selector section, 49... Test line switching section, 5 (5A, 5B
)...Time division switch, 6...Control device. IJ! eye/ (

Claims (1)

[Scope of Claims] 1. Each digital trunk is connected to the transmission path of its reception section and transmission section by separating the connection to the transmission path using a test line lead-out switch section, and connecting the reception section input side, the transmission section output side, and the upstream side and downlink side of the transmission path. It is designed so that each side can be pulled out separately as a test line, and it has two sets of the same receiver and transmitter as the above digital trunk, and the test lines of each of the above digital trunks can be connected in multiple ways. In a time division switch equipped with a digital trunk test device that can extract and insert signals related to digital trunk testing, when fault information is sent from the digital trunk, the test line pullout switch section is A digital trunk redundant configuration system characterized in that the test line is connected to a digital trunk test device, and one set of the receiving section and transmitting section is controlled and processed so as to operate as a backup substitute for the digital trunk. . 2. A digital trunk redundancy configuration system according to claim 1, in which the digital trunk that has transmitted the failure information is preliminarily switched to a digital trunk test position, and then the digital trunk is tested. . 3. The digital trunk redundancy configuration system according to claim 1, in which the digital trunk that sent the fault information is tested by a digital trunk test device, and then preliminary switching is performed.