JPS58225761A - Heat stand-by system - Google Patents

Abstract

PURPOSE:To place a stand-by channel switch module in an early heat stand-by state through simple processing without the intervention of the program of a common controller by transmitting and receiving data directly between two channel switch modules. CONSTITUTION:An in-use switch module SM sends state information for controlling an SM processor SPR from its memory M to a stand-by SM periodically and the contents of both memories M are made coincident with each other to obtain a heat stand-by state. In this case, the same transmitting/receiving channel as a channel for transmitting said signal is set even on the stand-by device side. When switch modules SM0#0 and SM0#1 are switched to a stand-by and an in-use side, respectively, a route switching FF.R-FF provided to a line circuit shelf common part LCSHC is reset and a switching circuit SW is changed over to switch a separating and multiplexing circuit from forward and backward main highways MHWFn1 and MHWBn1 of the SM0#0 which serves as an in- use device so far to the corresponding MHWs of the SM0#1 which serves as the in-use device nearly.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention utilizes a thermal reserve system, and more particularly, a method for duplicating communication line equipment by means of a switch module having distributed processing functions, and furthermore, a thermal reserve system configuration. This paper relates to a heat reserve method in a time-sharing digital switching system.

Background of the Technology In a time-division digital switching system, in order to prevent call interruptions in the event of a failure in a communication path device, the communication path device is duplicated, and the backup communication path device is made available for immediate use as the active system. It is necessary to wait.

In a time-division digital switching system with duplex communication path devices, in order to start up a communication path device that is on standby as a standby and use it as an active device, its control memory (path holding memory, gate holding memory, and line (e.g., memory that holds status information) must be set to be the same as the current active channel equipment. In order to switch between the active and standby devices without interrupting the call, it is necessary to keep the contents of the control memories of the active and standby devices always the same.

PRIOR ART AND PROBLEMS FIG. 1 is a block diagram showing the configuration of a time-division digital switching system with duplex communication path devices, in order to clarify the conventional backup system.

In Figure 1, SM. , S, and Msu1 are switch modules each including a time-division channel network TDNW and a channel control device SPC, one of which is used as an active system and the other as a standby system. Now, switch module SM0 is currently used, and SMφ1
shall be kept on standby as a reserve, and the main
Assume that processor MPRφ0 is currently in use.

In the case of the configuration shown in FIG. 1, according to the conventional technology, for example, a 2-bit name code is added to the main processor MPR in order from 0, and if the name code is 00, is invalid, 01 is valid only for switch module SMφ0, 10
, valid only for switch module SM1, 11 for switch modules SM0 and SM
Normally, the order is sent to both systems at the same time with a name code of 11, so that it is valid for both systems.
We planned to make the backup system (switch module SMφ1) hot.

In this case, the communication path control device spc does not have a processing function,
It only transmits the instructions of the main processor MPRφ0 to the time division channel device TDNiV. Generally speaking, the answer (dotted line in the figure) is not seen from the standby channel control device spc, so the standby line (switch module SAf$1)
) cannot be confirmed, and therefore it cannot be confirmed whether the standby system is in the same state as the active system.

FIG. 2 shows one step further in distributing processing functions compared to the time-sharing digital switching system of FIG. 1, and includes switch modules 5M40. Switch fist module processor 5PRo and SPR+ are added to SM◆1, respectively, and this makes main processor J/PRh+
, HMPR, is a block diagram showing the configuration of a time-division switch with duplex communication path devices when a part of the processing functions of the HMPR and the HMPR are shared.

(3) In this case, according to the above name code method, the switch module processor SPJ? of both switch modules SM+ 0 + SM+ 1 is transferred from the current main processor (nPR+o) to the switch module processor SPJ? of both switch modules SM+ 0 + SM+ 1. If 5PR1 is controlled simultaneously, this control will be performed through inter-processor communication.There is a risk that the processing in both switch module processors S, PRo, and 5PFt will not be synchronized.・
If you try to measure the thermal reserve of a module, the main process will be complicated and it will be difficult to actually use it.

Therefore, in such a case, according to the conventional technology, both switch module processors SPR, 5PRI,
A waiting buffer Qo provided for each.

For example, a current switch module processor (SPRo or 5
pxx) passes through the above-mentioned intersection R and periodically verifies the status information of the time-division communication network TDNW to the standby switch module processor. We planned to make the communication network TDNWO heat reserve.

However, according to the above prior art, the waiting buffer Q
o, Qt, and a crossroad R that passes through them.Also, additional programs and processing such as status information collation and checking are required, but these are quite complicated and heat-resistant. There were drawbacks, such as the difficulty of making preliminary preparations quickly and early.

Purpose of the Invention The present invention d1 In a time-division digital switching system in which the communication line equipment is duplicated by switch modules having distributed processing functions and also has a heat reserve configuration, heat reserve of the communication line switch module is provided. , the predetermined communication channels of the duplexed communication path switch module can be selected without going through the main device (main processor) module that controls the duplexed communication path switch module. It is assigned as a signal transmission/reception channel between the communication path switch modules, and the information necessary for thermal protection is directly transferred between the duplicated communication path switch modules via the signal transmission/reception channel. The purpose is to minimize the amount of additional hardware, to perform heat reserve early and quickly, without complicating processing without the intervention of communication control programs, etc.

Examples of the invention Embodiments of the present invention will now be described with reference to the drawings.

FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention. In this embodiment, the communication path switch module is duplicated, and four line circuits that are not duplicated can be switched and connected to one of the duplicated switch modules.

In the figure, LC5H is a line circuit shelf, LC5H
C is a line circuit shelf common section, SM□+o-5Mmsu0 and SMoφ1 to SMm◆1 are talk path switch modules, respectively, and SMQsu0 and SHOsu1.
~SAf company 0 and SM
When o=SM, , (+o) is operating as the current one, the other one (for example, SMo+1 to Sum◆1) is on standby as a reserve.

In line circuit shelf LC5E, Lcco~LC
Ci is a line circuit card, each of which is equipped with a plurality of line circuits LC, each of which is connected to a telephone (not shown).

The audio signal sent from the telephone is input to each line circuit LC, converted into 2-wire and 4-wire converted and digitized, and then input to the separation and multiplexing circuit 5pypx provided in the common section LcsHc of the line circuit shelf LC8H and multiplexed. .

Currently, switch module SMQ÷0 is currently in use, SMQ
Assume that ÷1 is the reserve. In this case, the route selection flip-flop R-FF provided in the line circuit shelf common part LC5HC is set, and its output "'1"
The switching circuit SW is controlled by the switching circuit SW, and as shown by the dotted line, the separation and multiplexing circuit SPMPX is connected to the forward main highway M of the current switch module 5Jfo+o.
It is connected to HWFtL1 and backward main highway MHW8U1.

(7) The voice signal sent from the telephone connected to the line circuit LC of the line circuit shelf LC5H to the switch module SMO+0 side is digitized and multiplexed as described above, passes through the switching circuit SF, and is sent to the switch module SMO+0. The forward main highway MHWFnj of module SMO+0 is input to the multiplexer MPX, and further forward main highways M
It is multiplexed with the call signal from the HWF construction station and sent to the forward call path memory S via Janfuta Highway.
Enter PMFn and write down 1. - to be done.

The switch module SMQsu0 includes, as a time division channel network, a multiplexer MPX6=MPXn, a demultiplexer DMPXO-DMPXn, a forward communication channel memory SPMF constituting a primary time switch,
-5PMF1, a backward channel memory S PMEo = SPMBrL constituting a secondary time switch, and a spatial switch 5-sr. Here, T-CNT is a time slot counter, HLM is a channel holding memory υ, and its contents are used in the channel memory SPMF6-5.
Reading of PMFn, SPMBo-5PMBn (8), 1. The space switch 5-5M controls the loading and converts the time slot, and the space switch 5-5M is set to
Exchange between highways entering and exiting the country.

The time slot counter T-CNT and the channel maintenance memo IJ IILM are each channel memo IJ (5pu
p, -sPMFn, SPMBo=SPMBn) to perform time slot swapping, that is, time switching, and the space switch S-5IV swaps highways according to the contents of the built-in gate holding memory. That is, spatial switching is performed and exchange is performed. Since this is well known, I will limit myself to the above general explanation.
Detailed explanation will be omitted.

In addition, backward communication path memory SPMEo-5PMB
The call signal read from n is sent to demultiplexer 1)
MPX6- In DMPXn, Backward Main Highway MEWB Exit 1~MHWBn1~
J/HFEnk, and as shown in the example for the backward main highway uHrrlBn 1, the input is input to the line circuit shelf common section LC5HC, and inputted from the separate input terminal of the separation and multiplexing circuit SPMPX via the switching circuit SF. It is separated into channels for each telephone and reaches the corresponding line circuit (r, c), where the speech signal in the form of a digital signal is decoded into an analog signal and 2
The signal is sent to the telephone via a 4-wire conversion circuit.

In this way, the exchange is performed, and the setting of the communication channel is determined by the contents of the communication path holding memory HLM and the contents of the gate holding memory built in the space switch sy, as described above.

In FIG. 6, PIA is a peripheral (including the communication path holding memory ELM and gate holding memory of the space switch 5-5F) control circuit, INT is an interface circuit with the main processor MPR, and SPR is a switch module. M is a processor, M is a memory IJ, DMA is a direct memory access I control circuit, ADLC is a communication control interface circuit, and B is a common bus within the switch module. In addition, I is inserter, DFi droppatial.

When setting or canceling a connection, the switch module processor SPR receives an order from the main processor MPR via the interface circuit INF and the common bus B, performs the prescribed processing, and connects the common bus B and the peripheral control circuit PIA. After that, the necessary data is written into the communication path holding memo IJELM and the gate holding memory. It is assumed that this information is also stored in memory H. The status of the phone is monitored and the status information is stored in memory M. Note that when the state of the telephone changes, the switch module processor SPR writes the state information in the memo IJM when this is detected. In this way, the latest status information of each telephone is always stored in the memo IJH.

A pair of switch modules (e.g. SMQ0 and S
When one of the un÷1) is currently in use, the memo IJ of both switch modules is
It is necessary to make the contents of H consistent with each other.

Therefore, the corresponding foo (11
) Cross-connect one word main highway and backward main highway with a cross cable to create a transfer route for the contents of memo IJ J(.In the case of the figure, switch
Switch the backward main highway xHWB o 1 of module SMo+o to module SM
Q◆1 Forward Main Highway MHWF
o 1 and also connects the backward main highway MHWBO1 of the switch module SMQφ1 to the forward main highway MHFF o 1 of the switch module SMQφ0. Furthermore, in the switch modules SMoφ0 and SMO+1, the predetermined speech channel of the forward main highway MHWFnk into which the inserter I is inserted is connected to the above-mentioned backward main highway M
The predetermined communication channel of the forward main highway MHWFQ1 is connected to the communication channel of the backward main highway HEWBnk in which the dropper D is inserted, and the inserter Set the channel holding memo IJ HLM and the gate holding memory of the space switch 5-sr so that the signal inserted from I is extracted from the dropper D via the above predetermined communication channel (12). do.

If the switch module SMo+0 is currently in use, the contents of this memory M are transferred from the transmission control circuit ADLC, inserter I, and forward main highway MHWFnk under the control of the direct memory access control circuit DMA. Output to backward main highway MHW'BQ1, and switch
From the forward main highway MHWFO1 of module SMQφ1 to the dropper D via the backward main highway MHWBrLk and then to the backup system switch module S via the transmission control circuit ADLC.
M, can be sent to the memory M of φ1.

With the above settings, the active switch module periodically transfers the contents of its memo IJH, such as status information managed by the switch module processor SPH, to the standby switch module. By sending the memo IJ J/, the contents of both memos can be made consistent and thermal preparation can be performed.

In this case, since a signal transmission/reception channel similar to the communication channel for transmitting the above-mentioned signals is set for the standby device, the normality of the communication path can also be confirmed.

In the above, when switch module 5AIQφ0 is switched to standby and switch module SMO≠1 is switched to active, the route I switching flip-flop R-FF provided in line circuit shelf common section LC5HC is reset.

As a result, the switching circuit SF is switched, and the separating and multiplexing circuit SPMPX, which was previously connected to the current switch module SMQ÷00 forward main highway MHTF'Fn 1 and backward main highway AfHFBn 1, is replaced with a new one. The corresponding main switch module SHO+ 1, which is currently in use,
connected to the highway.

Although only one line circuit shelf LC5H is shown in the figure, switch modules Suo+Q, SM
Main highway of Q÷1~ (MHWF ol ~M
HIi'F@pc, MH1r'E mouth 1~MHWBn
Needless to say, it is possible to provide a large number of them depending on the number of .l).

It is sufficient to allocate one communication channel on the main highway as a signal transmission/reception channel for transmitting the contents of the memo IJ J/. It is also possible to connect line circuit shelves using the channels.

FIG. 4 is a block diagram showing the configuration of a different embodiment of the present invention. In this embodiment as well, as in the embodiment shown in FIG.
The call path switch module is duplicated, but unlike the embodiment that accommodates telephones in Figure 3, a trunk that is not duplicated can be switched and connected to one of the duplicated switch modules. It becomes.

In the figure, TRKSHo and TRKSH1 are trunk shelves, respectively, Tm5HC1 and TnaHC1 are common parts of trunk-shelf TRKSH, TRKSH, respectively, and 5J10+0~! 5M1φ0 and SMo÷1 to SM-÷1 are respectively channel switch modules, and as in FIG.
SMQ◆0 and SMo◆1 to SM, φ0 and SM□su1, etc. each form a pair (15), one of which is in use and the other is reserved.

In the trunk shelves TRKSHo and TRKSH1, each of TC1 to TCi is a trunk card, each card is equipped with a plurality of trunks TRK, and a trunk line (not shown) is connected to each trunk TRK.

The speech signals from the trunk lines are 2-wire to 4-wire converted (if necessary) and digitized in each trunk to the trunk-shelf common section T=Il#SEC,.

Separation and multiplex circuit SP provided in Tm5HC1
It is input to MPX and multiplexed.

Currently, switch module S, MOφ0 is currently in use, SH
Assume that O◆1 is a reserve. In this case, the route selection flip-flops R-FF provided in the trunk/shelf common parts TfMISHC and Tm5HC1 are respectively set, and the p switching circuits 5Fl and 5F are controlled by the output "1#" as indicated by the dotted line. As shown in , the multiplexed output of the separation and multiplexing circuit SPMPX passes through the inserter I and the switching circuit 5F2 (dotted line) to the switch module SMQ◆00 forward May (16
), the inputs to the trunk switch modules 5Jfo+o of the trunk shelves TRKSHo and TRKSH, are multiplexed to the forward main highway MHWFo1 and ready for input to the multiplexer MPXO.

Trunk shelf TRKSHo and TRKSH above
The digitized speech signal sent from the trunk TRK mounted on the switch module SMO+0 to the switch module SMO+0 is multiplexed as described above to the forward main highway MHIVF o 1 and input to the multiplexer MPX. , Furthermore, the same multiplexer MPX
, the other forward main highway M
It is multiplexed with IIW'FD 2 to MHWFOk, is input to the forward channel memory SPMF via the Janfta Highway, and is temporarily stored.

The switch module SMQsu0 serves as a time-division channel network, including multiplexers MPX6-MPXn, demultiplexers DMPXo=DMPXn, and a forward channel memory SPMP constituting a primary time switch.
This embodiment is the same as the embodiment shown in FIG. 6 in that it includes backward channel memories 5PAfBo-SPMBn constituting SPMF, secondary time switches, and space switches 5-5F between the primary and secondary time switches. Here T-
CRT is a time slot counter, and HLM is a channel holding memory, whose output is used as an address to use the channel memory SPMF6-5PMFn, SPMB6-5F.
Read MBn.

Control writes and swap time slots,
Similarly to the embodiment shown in FIG. 6, the space switch 5-5W performs exchange between the input and output highways of the space switch 5-5F depending on the contents of the built-in gate holding memory.

That is, the time slot counter T-CNT and the channel maintenance memo IJ ELM are stored in each channel memory (5
PA (Fo-SPMFn, SP, MBo-SPMB
n) to control its read and write operations, and swap the time slots, i.e.,
Performs time switching and also space switch 5-5F
The system controls the opening and closing of gates and performs space switching according to the contents of the built-in gate holding memory, and exchanges between trunks are performed. Since this is well known, I will only give a brief explanation.

In addition, backward communication path memory SPMB6-SPM
The call signal read from Bn is sent to the demultiplexer D.
At MPXo - DMPXn, the backward main highway MHTF'E (31 to MHWB
, 1 to hlHWBnk, and as illustrated for the bankward main highway MHWBQ, it branches into two at its output, one branching to the trunk shelf TRKSHo and the other branching to the trunk shelf TRKSHo.
Enter in H1. For example, trunk shelf TRKS
At H, there is a branched backward main highway J (HWBOl is a dropper D,
via a separation and multiplexing circuit SPMPX, where the call signal is separated into each trunk of the trunk shelf TRKSHo.

Trunk shelf 1'RKSH is handled in the same way as above, except for the call signal and trunk shelf TRKSH that should be output to trunk shelf TRKSHo.

The call signal to be output to Bankward Main Highway AfHWBO1 is at a different time point (19
), it is possible to separate the call signals for each trunk without any problem.

Note that this is a status signal sent via a relay line.

The control circuit is extracted from the guest room, digitized here, and the signal of the trunk is The inserter 11
Insert in.

This signal is the forward channel memory sPMFo~S
It is extracted and separated at the dropper D2 provided at the output part of PMFn, and then sent to the switch module processor SPH.
The status of the trunk line or trunk is monitored here.

The non-speech signal to be sent to the trunk line or trunk is sent from the switch module processor SPR to the inserter I2 provided at the input end of the backward communication path memory SPMB6-SPJ/Bn at the time position corresponding to the corresponding trunk line or trunk. , Di (20) is inserted in the form of digital Shingetsu. This non-call signal is carried to the trunk shelf via the backward main highway. Backward Main Highway MHWBO1 and Trunk Shelf T shown in the drawing
Taking RKSHo as an example, a digital non-speech signal carried at a time position corresponding to a certain relay line or trunk on the backward main highway MHWE ol is extracted at a dropper Dl and drawn into the signal control circuit SGC. . The signal control circuit SGC determines the relay line or trunk (the number) and the content of the signal to be sent from the time position of the signal when it is pulled in and its content, and sends out the signal corresponding to the corresponding trunk.

That is, on during non-speech signals carried by the trunk line.

The off signal and dial signal are detected by the switch module processor SPR as described above, and based on this, the communication path maintenance memo IJ HLM and the space switch 5 are detected.
- The contents of the gate holding memory of 5F are set, connection to the trunk line specified by the dial signal is executed, and the on/off signal carried by the trunk line is transmitted to the switch module processor SPR in the same manner as above. detected,
From this signal, the status of the trunk line or trunk is identified and a status signal-1 is generated, which is stored in the switch module processor SPR or in a memory accessible from the processor SPR.

One backward main highway of the switch module SMQφ0, for example MHWBOl, branches at the input of the switching circuit SFI of the trunk shelf common section TSHCI, and branches off at the input of the switching circuit SFI of the trunk shelf common section TSHCI.
It reaches the front connector t'C of the trunk shelf TRKSHo through the front connector FC and the crossover cable RC, and further passes through the output of the switching circuit SF of the trunk shelf common section TSHCO, and then connects the unpaired switch.
The module SMQ÷1 is connected to the 7-Oward Maini/Highway MHWFQ1. In addition, one backward main highway of switch module SMO÷1, for example, MHWBOl, branches at the input part of the switching circuit SW1 of the trunk shelf common part TSHCO, connects to the front connector FC of the trunk shelf TRKSIIO, and crosses the cable. Through RC, it reaches the front connector FC of the trunk shelf TRKSHI, and then the switching circuit SW2 of the trunk shelf common section TSHC.
At the output of the paired switch module SM
Qφ0 forward main highway MEIr'
Connect and merge with Fo1.

A communication path is maintained so that one predetermined communication channel of the iMHWFnk is connected to one predetermined communication channel of the backward main highway MIWBQJ of the isoswitch module SHO÷0. Set the gate holding memory of Memo IJ Hl, M and space switches 5-5F.

In the switch module SM[11, it is connected to the backward main highway MHWBQ1 of the switch module SMQ÷0 as described above.
! Forward Main Highway MHWFQ1
One predetermined communication channel of Dorotsuba D
The communication path holding memory HLM and the gate holding memory of the space switch 5-5F are set so as to connect to the inserted backward main channel MHWEnk of 3 (23).

That is, from the switch module 5ArQ00 inserter, one communication channel is sent to the forward main highway M of the switch module SMQ00.
HWF n k to the same backward main highway MHH'Bo 1, and further to this barrack shelf TRX5H1, front connector FC, cross cable RC, front connector FC of rank shelf TRKSHo, switch module 5MQ The backward main highway of the switch module SMQ◆1 is connected to the forward main highway MHWFQ1 of
The path-keeping memory HLM of the switch modules SMOsu0 and SMOsu1 is configured to reach the Drotsuba D3 inserted in the main highway MHFBnk.
and set the gate holding memory of the space switch 5-5H'.

(24) In addition, from inserter I3 of switch module 5JfO+1 to dropper D of switch module SMO÷0
Similarly to the above, one communication channel is also set for 3.

Therefore, switch modules SMo+o and SMO
The data inserted into the inserter I3 of φ1 is sent to the partner switch modules SHOφ1 and 5J10+, respectively.
It can be extracted from Drotsuba D3 of 0.

With the above settings, the current switch module periodically stores the contents of the channel holding memory HLM and the gate holding memory of space switches 5-5F, and the state information of each trunk line. (not shown) in its switch module processor SPR
From there, it can be sent to the switch module processor SPR of the other party's standby switch module through the inserter I3 and dropper D3. Alternatively, the data may be sent without delay, instead of periodically, each time a change occurs in the contents of each of the memories.

The spare switch module receives the above data from the current switch module, sets each memory, and makes it a thermal standby.

In Figure 4, the trunk/shelf common part TSHC
Flip-flop R for route selection of O and TSHCg
- All FFs are set, trunk shelf T
RKSH and TRKSHs are connected to the current switch module SMO#0. When switching the switch module SMO+0 to the standby mode and the switch modules SM and S1 to the current mode, the states of the route selection flip-flops R-FF are changed.

In this case, it will be reset.

This reset causes the route selection flip-flop R-
FF outputs 0'', and each switching circuit SF
1. SF2 is the trunk/shelf common part TSHCo
and TSHC, the main cable input/output to/from switch module SM, SQ is switched to switch module SM, S1. However, the communication channel set from inserter I3 of each switch module mentioned above to Drotsunoku D3 is not affected in any way and continues as is, and the contents of each memory of the working switch module are transferred to the spare switch module. .

Although the present invention has been described in detail above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the technical scope thereof.

Effects of the Invention Since the present invention is configured as described above, in a time-division digital converter system in which the communication path switch module is duplicated, the heat reserve of the spare communication path switch module is made redundant. Since data is directly sent and received between the duplicated communication path switch modules without going through a common control device (for example, a main processor) that controls the communication path switch modules mentioned above, This makes it possible to quickly restore heat to the standby communication path switch module through simple processing without requiring intervention such as a restart processing program or a communication control program for the control device (main processor) of the main processor, and prevents the current machine from failing. This has the effect of quickly switching over to the standby (27) machine and quickly resuming the call.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a time-division digital switching system with duplexed call path switch modules to explain a conventional protection system, and FIG. FIG. 3 is a block diagram of a time division digital switching system in which the present invention is implemented, and FIG. 4 is a block diagram of a different embodiment of the present invention. be. SMsuO, SMsu1. SMOφ0~SM door 0. SMQ
1~SM 1 °ゝ゛ Switch module, T
DNW... Time division communication path network, spc... Communication path control device, SPR, 5PR6, 5PR1... Switch module processor, MPR, MPRφQ, MP
Rφ1...Main processor, QOIQI...Register for waiting, R...Crossroads, J(mf'FQ1~MHW
Fnk...Forward-Main Highway, MH
TF'B01~MHWBnk...) Kutsukword-
Main highway, MPXo=MPXn...Multi (28) Plexer, DMPX6- DMPXn...Demultiplexer, SPMFo -SPMPn...Forward data channel memory, SPMEo''-SPMEn...
Backward channel memory, T-CNT...time...
Slot counter, HLM...communication path maintenance memory,
5-5F...Space switch, 1, 11, 12゜I3
...Inserter, D+ DI HD2 + DI・
...Dorotsunoku, B...Common bus, ADLC...Transmission control circuit, DMA...Direct memory access control circuit, PIA...Peripheral control device, y...Memory, INT... Interface circuit, LC5H...
Line circuit shelf, LC5EC... Line circuit shelf common part, LCCO-LCCi... Line circuit card, LC... Line circuit, 5pxpx... Separation and multiplex circuit, SF, SF, , SF,... Switching circuit, R-FF...flip-flop for route selection,
7Rf5N6 + TRKSHl... Trunk shelf, TSHCo, TSHcl... Trunk φ shelf common part, SGC... Signal control circuit, TCl-T
Ci...Trunk card, TRK...Trunk, F
C...Front connector, RC...Cross cable Patent applicant Fujitsu Limited

Claims (1)

[Claims] In a time-division digital switching system in which communication path devices are duplicated by switch modules having distributed processing functions, and which also has a heat reserve configuration, the predetermined The communication channel is assigned to the signal transmission/reception channel between the communication path switch modules, and the information necessary for thermal backup of the backup communication path switch module, such as the control memory information of the active communication path switch module, is stored as described above. A heat reserve method characterized by transferring heat on a transmitting/receiving channel to provide heat reserve for a standby communication path switch module.