JPH05227582A - Digital exchange - Google Patents

Abstract

PURPOSE:To provide a digital exchange which can raise the multiplex rate of the number of terminal circuits to one high way even to a high traffic which locally generates. CONSTITUTION:The digital exchange is provided with a subscriber's circuit 8, a multiplexing/separating circuit 6, a multiplexing/separating circuit control part 7, a main high way 9, a sub high way 10, a calling route switch 4, a sub high way management part 11 and a calling processing part 3. When there is no idle time slot on the main high way 9, the multiplexing/separating circuit control part 7 assigns a time slot on the sub high way 10 managed by the sub high way management part 11. Thus, with regard to a connection requirement locally generated at not less than the time slot, connection is possible through the use of the traffic for the surplus of the time slot of the common sub high way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital exchange, and more particularly, to efficiently switching the highway configuration when switching the highway configuration of a transmission line between a speech path switch and a subscriber line circuit in the digital exchange. The present invention relates to a digital exchange capable of

[0002]

2. Description of the Related Art Conventionally, in a switching system in which connections between lines such as a digital switching system are switched by a communication path switch, it is practically problematic that calls are rarely made simultaneously on all the lines accommodated in the switching system. The number of lines accommodated in the exchange is set to a value larger than the capacity (number of time slots) of the speech path switch within a range that guarantees an appropriate block rate to the extent that there is no Is configured so that the highway can be efficiently used.

FIG. 5 is a block diagram showing an outline of a configuration example of a conventional digital exchange. In FIG. 5, 1 is a subscriber line, 2 is a subscriber line circuit group in a circuit switching control unit, 3 is a call processing unit, 4 is a speech path switch, 5 is a highway, and 6 is a signal line from a plurality of subscriber circuits. Is a multiplexing / demultiplexing circuit unit, 7 is a multiplexing / demultiplexing circuit control unit, and 8 is a subscriber circuit. In the digital exchange here, as shown in FIG. 5, each subscriber line 1 is connected to the exchange through a subscriber line circuit 8 serving as a connection port of the digital exchange. A plurality of signal lines from the respective subscriber circuits 8 are multiplexed by the multiplexing / demultiplexing circuit unit 6, and the multiplexed signals are passed through the highway 5 to the speech path switch 4
, And the circuit switching between the respective highways 5 is performed by the speech path switch 4. The multiplexer / demultiplexer circuit controller 7 is a controller that controls the multiplexer / demultiplexer circuit unit 6 and controls the allocation of time slots to the signal lines of the respective subscriber circuits 8. Further, the call processing unit 3 controls the multiplexing / demultiplexing circuit control unit 7 and the communication path switch 4. In the overall circuit switching control between the respective subscriber lines 1 here, the call processing unit 3 gives an instruction to the multiplexing / demultiplexing circuit control unit 7 to control the multiplexing / demultiplexing circuit unit 6, and This is performed by the call processing unit 3 directly controlling the communication path switch 4.

In the digital exchange as shown in FIG. 5, in order to efficiently use the highway 5 as described above, it is multiplexed to a plurality of subscriber circuit groups 2 of multiplexing units connected to the highway 5.・ Separation circuit 6 and multiplex
A separation circuit control unit 7 is provided, and the number of subscriber line interface circuits (subscriber circuits; terminals) connected to the highway 5 is set to be equal to or greater than the number of highway time slots.

FIG. 6 is a block diagram showing the outline of another configuration example of a conventional digital exchange. In FIG. 6, 1 is a subscriber line, 2 is a subscriber line circuit group of a circuit switching control unit,
3 is a call processing unit, 4 is a communication path switch, 5 is a highway,
Reference numeral 6 denotes a multiplexing / demultiplexing circuit unit for multiplexing signal lines from a plurality of subscriber circuits, 8 denotes a subscriber circuit, and 17 denotes a multiplexing / demultiplexing circuit control unit. The digital exchange shown in FIG.
The basic configuration and operation are the same as those of the digital exchange shown in FIG. 5, but a multiplexing / demultiplexing circuit control unit 17 for controlling the multiplexing / demultiplexing circuit unit 6 is provided for each multiplexing / demultiplexing circuit unit 6. First, in order to measure the overall efficient use of the highway, one multiplexer / demultiplexer circuit controller 17
The multiplex / demultiplex circuit unit 6 is controlled.

Even in such a digital exchange,
As mentioned above, in order to efficiently use the highway 5,
The subscriber line interface circuit (subscriber circuit) connected to the highway 5 is set to have more circuits than the number of time slots on the highway. A known document relating to this type of digital exchange is, for example, Japanese Patent Laid-Open No. 62-
No. 64158 is cited.

[0007]

By the way, the above-mentioned FIG.
In a digital exchange such as that shown in FIG. 2, when the traffic of a subscriber line circuit group connected to a certain highway increases locally and exceeds a set utilization rate, a block state occurs on the highway. In this case, in order to avoid the block state, the number of time slots of one highway is increased, or the number of highways is increased and the number of subscriber line circuits connected to one highway is reduced to multiplex. It is necessary to reduce the rate of conversion. That is,
In order to cope with local high traffic, it is necessary to keep the multiplexing rate of the number of circuits per highway low, which makes it difficult to increase the highway usage efficiency.

However, when the number of time slots per highway is increased, it is necessary to change the configuration of the entire device including the speech path switch and simultaneously increase the processing speed of the speech path switch. There is a limit to the increase.

In order to measure the effective use of the time slots, for example, the configuration of the digital exchange is configured so that the multiplexing / demultiplexing circuit control unit manages the entire highway as shown in FIG. There is also a method of managing the entire highway of the speech path in the demultiplexing / demultiplexing circuit control section and mutually utilizing the empty time slots of other highways among multiple highways. Since the connection switch portion has a matrix structure, there is a problem that the number of interconnection circuits between highways increases rapidly with the increase of highways, and the processing for time slot management and control becomes complicated.

The present invention has been made to solve such a problem, and an object of the present invention is to multiplex the number of terminal circuits for one highway for locally generated high traffic. It is to provide a digital exchange that can increase the rate.

[0011]

To achieve the above object, in the digital exchange of the present invention, a plurality of line interface circuits (8; FIG. 1) for accommodating lines are provided.
A plurality of demultiplexing / demultiplexing circuits (6; FIG. 1) for demultiplexing / demultiplexing each of a predetermined number of the plurality of line interface circuits; A demultiplexing circuit controller (7; FIG. 1), a plurality of main highways (9; FIG. 1) respectively connected to the plurality of demultiplexing / demultiplexing circuits, and at least a part of the plurality of demultiplexing / demultiplexing circuits. A sub-highway (10; FIG. 1) connected to the separation circuit, a speech path switch (4; FIG. 1) for switching the connection between the main highway and the sub-highway, and the sub-highway connected to the sub-highway A sub-highway management unit (1 that manages a time slot allocation request on the sub-highway from the demultiplexing / demultiplexing circuit control unit
1; and FIG. 1), and a call processing unit (3; FIG. 1) for controlling the multiplexer / demultiplexer circuit control unit and the communication path switch based on the information from the multiplexer / demultiplexer circuit controller and the sub highway management unit. In the digital switch having the above, the demultiplexing / demultiplexing circuit control unit (7; FIG. 1) manages the sub highway management unit (11; FIG. 1) when there is no empty time slot on the main highway. It is characterized by allocating time slots on the secondary highway.

[0012]

In the digital exchange of the present invention, a plurality of line interface circuits (subscriber circuits) are provided to serve as connection ports for lines to be exchanged, and a predetermined number of sets among the plurality of subscriber circuits are provided. Multiplex / multiplex multiple
A separation circuit is provided for multiplexing. The plurality of multiplexing / demultiplexing circuits are controlled by their respective multiplexing / demultiplexing circuit controllers. The signal lines multiplexed by the multiplexing / demultiplexing circuit are connected to a plurality of main highways,
In addition, at least a part of the signal lines multiplexed by the multiplexer / demultiplexer circuit is connected to the sub highway, and in the speech path switch, the connection between the main highway and the sub highway is changed. Can be switched.

The sub-highway management unit manages a time slot allocation request on the sub-highway, and as a part of a signal path to be multiplexed by the demultiplexing / demultiplexing circuit on the sub-highway according to the request from the demultiplexing / demultiplexing circuit control unit. Allocate the time slot of. Further, the call processing unit, based on the information from the demultiplexing / demultiplexing circuit control unit and the sub highway management unit,
Controls the separation circuit controller and the speech path switch. In such a digital exchange, when the circuit is switched, the multiplexer / demultiplexer circuit control unit controls the multiplexer / demultiplexer circuit to allocate the time slot of the main highway, and when the line is multiplexed, the main highway If there is no free time slot above, the time slot on the sub highway managed by the sub highway management unit is allocated.

As described above, in the digital switching apparatus, the highway is composed of the main highway and the sub highway, the main highway is connected with a single or a plurality of multiplexing / demultiplexing circuits, and the sub highway is connected with the main highway. As a configuration in which all the multiplexing / demultiplexing circuits are connected, time slots can be allocated to the subscriber line circuits at any time when setting a communication path. When there are no empty time slots on the main highway, the time slots on the sub highway can be assigned, so that more subscriber line circuits than the number of time slots on the highway can be accommodated.

That is, in the digital exchange of the present invention, when the call volume is less than or equal to the total number of time slots for each highway constituting the main highway, only the time slots of the main highway are used, and the call for the total number of time slots or more is performed. When the amount is generated, the surplus traffic is connected using the time slot of the shared sub highway. As a result, the communication capacity per main highway can be maximized as compared to the configuration of only the main highway, and the communication capacity including the main highway and the sub highway can be increased.

Therefore, with a simple configuration in which a small number of secondary highways are added, it is possible to set a high terminal multiplexing rate for one highway with respect to locally generated high traffic. It is possible to increase the utilization efficiency of each highway without increasing the number of slots and speeding up the communication path switch.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a main part of a digital exchange according to an embodiment of the present invention. In FIG. 1, 1 is a subscriber line, 2 is a subscriber line circuit group in a circuit switching control unit, 3 is a call processing unit, 4 is a speech path switch,
6 is a multiplex for multiplexing signal lines from a plurality of subscriber circuits.
A demultiplexing circuit unit, 7 is a multiplexing / demultiplexing circuit control unit, 8 is a subscriber circuit, 9 is a main highway, 10 is a sub highway, and 11 is a sub highway control unit. In the digital exchange here, as shown in FIG. 1, each subscriber line 1
Is a subscriber line circuit 8 that serves as a connection port to the digital exchange.
Is connected to the exchange through. Here, the subscriber line 1 is simply used as a line regardless of the type of extension line, external line (station line), dedicated line, or the like. A plurality of signal lines from each subscriber circuit 8 are multiplexed by the multiplexing / demultiplexing circuit unit 6,
In the circuit switching control unit of the subscriber line circuit group 2, the multiplexed signal is connected to the speech path switch 4 via the main highway 9 and simultaneously connected to the speech path switch 4 via the sub highway 10. To be done. The speech path switch 4 performs circuit switching for connecting speech paths between the respective main highways 9 and between the main highway 9 and the sub highways. Multiplex
The demultiplexing circuit control unit 7 is a control unit that controls the demultiplexing / demultiplexing circuit unit 6 and controls the allocation of time slots to the signal lines of the respective subscriber circuits 8. The call processing unit 3
It controls the separation circuit control unit 7 and the speech path switch 4.

For the overall circuit switching control between the respective subscriber lines 1, the call processing unit 3 gives an instruction to the multiplexing / demultiplexing circuit control unit 7 to control the multiplexing / demultiplexing circuit unit 6. ,
This is performed by the call processing unit 3 directly controlling the communication path switch 4 and the sub highway control unit 11.

As described above, in the digital exchange of this embodiment, the plurality of subscriber line circuits 8 are the subscriber circuit groups 2
Is connected to the multiplex / demultiplexer circuit unit 6 and is connected to both the main highway 9 and the sub highway 10 via the multiplex / demultiplexer circuit unit 6 via respective paths. The main highway 9 and the sub highway 10 are connected to the communication path switch 4. The main highway 9 is composed of a plurality of highways, and each highway is connected with a single or a plurality of multiplexing / demultiplexing circuits 6. The sub highway 10 is composed of a single highway or a plurality of highways. To the sub highway 10, a plurality of multiplexing / demultiplexing circuits 6 having connection routes in the main highway 9 are connected.

The multiplexing / demultiplexing circuit control unit 7 controls the multiplexing / demultiplexing circuit unit 6 to execute the time slot allocation processing of the main highway 9, and the sub highway control unit 11 controls the time slot of the sub highway 10. Execute the allocation process. Further, the call processing unit 3 executes call processing based on the call control information from the subscriber line circuit 8 and the time slot allocation information from the multiplexing / demultiplexing circuit control unit 7 and the sub highway control unit 11.

Next, an outline of the operation will be described. For example,
When there is an incoming call from the subscriber line 1, the subscriber line circuit 8
Notifies the call processing unit 3 of the call control information. At the same time, the multiplexer / demultiplexer circuit controller 7 is requested to allocate the time slot of the main highway 9. The multiplexing / demultiplexing circuit control unit 7
If there is an empty time slot on the main highway 9, the empty time slot number is assigned to the multiplexing / demultiplexing circuit unit 6 and the call processing unit 3.
To notify. Then, in the multiplexer / demultiplexer circuit unit 6, the signal of the subscriber line circuit 8 having received the call in the empty time slot of the main highway 9 is multiplexed to connect the speech path from the subscriber circuit 8 to the communication path switch. I do.

Further, in response to the request from the subscriber circuit 8 here, if there is no empty time slot in the main highway 9, or if the sub highway 10 is not provided,
Although the subscriber line circuit 8 and the communication path switch 4 cannot be connected in the blocked state, in the case of the configuration in which the sub highway 10 is provided as in the configuration here, the demultiplexing / demultiplexing circuit control unit 7 controls the sub highway. Request a time slot to the unit 11. The sub highway controller 11 manages the sub highway 10, searches for an empty time slot of the sub highway 10, and if there is an empty time slot, notifies the multiplexing / demultiplexing circuit controller 7 of the number of the empty time slot. .. The multiplexing / demultiplexing circuit control unit 7 notifies the multiplexing / demultiplexing circuit unit 6 and the call processing unit 3 of the numbers of the empty time slots, and uses the empty time slots to switch the call path switch 4 from the subscriber line circuit 8. Connect the call path up to.

In the case of the outgoing call processing, the multiplexer / demultiplexer circuit control section 7 and the sub highway control section 11 respond to the connection request from the call processing section 3 in the same manner as in the case of the incoming call. By allocating the vacant time slot of the highway 10 to the target subscriber line circuit 8, the communication line from the call line switch 4 to the subscriber line circuit 8 is connected.

In this way, with respect to the local block state that has occurred in each main highway 9, the surplus traffic in the sub highway 10 is used and the sub highway 10 shared by the plurality of main highways 9 is used. By bypassing the connection route, it becomes possible to avoid the blocked state and execute communication. Further, compared to the case where the multiplexing / demultiplexing circuit unit 6 is connected to a single highway,
It is possible to allocate a capacity corresponding to the communication capacity of the sub-highway 10 to a single highway, and it is possible to increase the multiplexing rate of the subscriber line circuit per highway.

FIG. 2 is a block diagram showing the configuration of a digital exchange according to an embodiment of the present invention in more detail. 2, the same elements as those of the digital exchange of FIG. 1 are designated with the same reference numerals. The basic structure of the digital exchange is the same as the structure shown in FIG.
A plurality of subscriber circuits 8 serving as connection ports for the subscriber circuit group 2
Is connected to one demultiplexing / demultiplexing circuit unit 6, and the plurality of demultiplexing / demultiplexing circuit units 6 are connected to the main highway 9 and the sub highway 10 to form a speech path route connected to the communication path switch 4. It The multiplexing / demultiplexing circuit unit 6 is controlled by the multiplexing / demultiplexing circuit control unit 7, multiplexes signals from the subscriber line circuit 8, and multiplexes and separates the signals. Further, a call processing unit 3, a sub highway control unit 11, a sub highway control communication line 12, and a signaling signal line 13 are provided for call processing and exchange control of a call route here.

The subscriber line circuit 8 is, for example, a digital / digital
It is an interface (connection port) with various circuits such as analog extension lines, office lines, and leased lines, and each subscriber line circuit 8
Converts the signal on the subscriber line 1 into a digital signal that can be processed in the switching equipment. The digital signal exchanged by the subscriber line circuit 8 is an 8-bit digital signal corresponding to the time slot on the highway. A plurality of subscriber line circuits 8 are connected to the multiplexer / demultiplexer circuit unit 6 to multiplex / demultiplex signals between the subscriber line circuits 8 and time slots on the highway. The multiplexing / demultiplexing circuit unit 6 is connected to both the main highway 9 and the sub highway 10. A plurality of subscriber line circuits 8, multiplex / separation circuits 6 and multiplex / separation circuit control units 7 connected to one main highway 9 are one group (subscriber circuit group 2) which is a unit of one exchange control. Make up.

When the subscriber line circuit 8 receives an incoming call, the subscriber line circuit 8 sends the signal to the multiplexer / demultiplexer circuit control unit 7 through a signal line (not shown) to the multiplexer / demultiplexer circuit 6 in the group to which it belongs.
A request for a time slot for multiplexing is issued, and at the same time, the call processing unit 3 is notified of the call control information via the signaling signal path 13. The demultiplexing / demultiplexing circuit control unit 7 searches for an unused time slot out of the time slots of the main highway 9, and if there is an empty time slot, assigns an empty time slot number to the subscriber line circuit 8, and the call processing unit Notify the time slot number to. The call processing unit 3 executes call processing based on the notified call control information and time slot number, and multiplexes the group to which the incoming subscriber line circuit 8 and the connected subscriber line circuit 8 belong. Instruct the separation circuit control unit 7 to connect the main highway 9. As a result, the multiplexer / demultiplexer circuit unit 6 multiplexes a signal into the empty time slot allocated to the subscriber line circuit 8 in accordance with the connection request from the call processing unit 3, and the subscriber line is routed through the main highway 9. The circuit 8 and the speech path switch 4 are connected.

By the way, when the incoming call to the subscriber line circuit 8 is made, the multiplexer / demultiplexer circuit control unit 7 searches for an unused empty time slot among the time slots assigned to the main highway 9. If there are no slots, the multiplexing / demultiplexing circuit control unit 7 requests the sub-highway control unit 11 via the sub-highway control signal path 12 to use the time slot on the sub-highway 10. The sub highway control unit 11 searches for an unused free time slot on the sub highway 10, and if there is a free time slot, notifies the time slot number to the multiplexing / demultiplexing circuit control unit 7. The multiplexing / demultiplexing circuit control unit 7 notifies the multiplexing / demultiplexing circuit unit 6 of this time slot number, and at the same time,
Similar to the case of the main highway 9, the empty time slot number of the sub highway 10 is notified to the call processing unit 3 via the signaling signal path 13. As a result, the multiplexer / demultiplexer circuit unit 6 associates the subscriber line circuit 8 with the empty time slot number of the sub highway 10 and multiplexes the signal on the sub highway 10 to join via the sub highway 10. The trunk line circuit 8 and the communication path switch 4 are connected.

Next, the call processing unit 3 checks the state of the subscriber line circuit 8 of the connection destination, and if the subscriber line circuit 8 is in the unused state, the multiplex / sub unit belonging to the target subscriber line circuit 8 is checked. It requests the separation circuit control unit 7 to allocate a time slot. The destination multiplex / demultiplex circuit control unit 7 to which the time slot allocation request is made, together with the sub-highway control unit 11, operates in the same manner as the operation on the receiving side to set an empty time slot in order of the main highway 9 and the sub-highway 10. If there is an empty time slot, the multiplexing / demultiplexing circuit unit 6 and the call processing unit 3 are notified. As a result, the multiplexer / demultiplexer circuit unit 6 connects the allocated empty time slot and the subscriber line circuit of the connection destination. The call processing unit 3 connects the call paths between the subscriber line circuits 8 by controlling the call path switches for the connected time slots of the called subscriber line circuit and the connected subscriber line circuit, respectively. Then, the call processing is completed.

Next, in such call processing, the control processing of the multiplexing / demultiplexing circuit control section 6 and the control processing of the sub highway control section 11 for performing the multiplexing control of the communication route of the main highway and the sub highway are performed. The time slot allocation processing will be described. FIG. 3 is a flowchart showing a processing example of time slot allocation control in the multiplexing / demultiplexing circuit control section, and FIG. 4 is a flowchart showing a processing example of time slot allocation control in the sub-highway control section.

First, the time slot allocation processing in the multiplexing / demultiplexing circuit controller will be described with reference to FIG. In this process, first, in step 30, when a time slot allocation request from the subscriber circuit or the call processing unit is received, then in step 31,
Check for empty time slots in the main highway (#m) management table. Based on the result of this check, in the next step 32, it is determined whether or not there is a vacancy (time slot). If there is an empty time slot, the process proceeds to the next step 33, and in step 33, the call processing unit is notified that the empty time slot (#q) of the main highway (#P) is assigned to the subscriber circuit (#n). In the next step 34, similarly, the subscriber circuit (#n) is notified that the vacant time slot (#q) of the main highway (#P) is assigned to the subscriber circuit (#n), and the processing is terminated. To do.

On the other hand, in the judgment processing of step 32,
If it is determined that there is no empty time slot, the process proceeds to step 35 in order to allocate an empty time slot on the sub highway. In step 35, a request for allocating an empty time slot of the sub highway is transmitted to the sub highway controller. Then, in the next step 36, the process by the sub highway controller (the process of FIG. 4) is performed. Next, in step 37, as a result of the processing by the sub highway control unit, it is determined whether or not the sub highway time slot can be assigned.

If it is determined in step 37 that the time slot on the sub highway can be allocated, the process proceeds to step 38, and the empty time slot (#r) on the sub highway is set to the subscriber circuit (#n). To the call processing unit, and in the next step 39, similarly, assigning an empty time slot (#r) of the secondary highway to the subscriber circuit (#n) is performed.
n) is notified and the process is terminated.

If it is determined in step 37 that the time slot on the sub highway cannot be assigned, the process proceeds to step 40. In step 40, the call processing unit is notified of the refusal of the allocation of the empty time slot to the subscriber circuit (#n), and in the next step 41, similarly, the rejection of the allocation of the empty time slot to the subscriber circuit ( #N) is notified and the process is terminated.

Next, with reference to FIG. 4, a time slot allocation process in the sub highway controller will be described. In this process, first, in step 42, when a time slot allocation request is received from the multiplexing / demultiplexing circuit control unit, in step 42, an empty time slot in the sub highway management table is checked. Based on the result of this check, in the next step 44, it is determined whether or not there is a vacancy (time slot). If there are free time slots, the next step 45
Then, in step 45, the multiplexing / demultiplexing circuit control unit (#m) is notified of the allocation of the free time slot (#s) of the sub highway, and the process is terminated. If there is no empty time slot, the process proceeds to the next step 46 to notify the demultiplexing / demultiplexing circuit control unit (#m) of refusal of allocation of the empty time slot, and the process is terminated.

As described above, according to the digital exchange of the present embodiment, when there is no empty time slot in the main highway in response to the request from the subscriber circuit, the demultiplexing / demultiplexing circuit control unit becomes the sub highway control unit. The sub-highway control unit searches for an empty time slot in the sub-highway and notifies the demultiplexing / demultiplexing circuit control unit of the empty time slot number. The road switch can be connected. As a result, the multiplexer / demultiplexer circuit unit can connect the speech path from the subscriber line circuit to the speech path switch by utilizing the empty time slot of the sub highway.

[0037]

As described above, according to the digital exchange of the present invention, excess traffic is shared by a plurality of main highways with respect to the local block state that occurs in each main highway. By detouring to the sub highway, it becomes possible to avoid the blocked state and execute communication. For this reason, compared to the case where the multiplexing / demultiplexing circuit is connected to a single highway, it is possible to allocate a capacity equivalent to the communication capacity of the sub-highway to the single highway, and the subscriber line circuit per highway. It is possible to increase the multiplexing rate of. A highway can be efficiently constructed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of a digital exchange according to an embodiment of the present invention,

FIG. 2 is a block diagram showing the configuration of a digital exchange according to an embodiment of the present invention in more detail;

FIG. 3 is a flow chart showing a processing example of time slot allocation control in the multiplexing / demultiplexing circuit control unit;

FIG. 4 is a flowchart showing a processing example of time slot allocation control in the secondary highway control unit,

FIG. 5 is a block diagram showing an outline of a configuration example of a conventional digital exchange,

FIG. 6 is a block diagram showing an outline of another configuration example of a conventional digital exchange.

[Explanation of symbols]

1 ... subscriber line, 2 ... subscriber line circuit group, 3 ... call processing unit,
4 ... Call path switch, 5 ... Highway, 6 ... Multiplexing / separating circuit section, 7 ... Multiplexing / separating circuit control section, 8 ... Subscriber circuit,
9 ... Main highway, 10 ... Sub highway, 11 ... Sub highway controller, 12 ... Sub highway control communication path, 13 ...
Signaling signal path, 17 ... Multiplexing / demultiplexing circuit controller.

Claims (1)

[Claims] 1. A plurality of line interface circuits for accommodating lines, a plurality of demultiplexing / demultiplexing circuits for demultiplexing every predetermined number of the plurality of line interface circuits, and a plurality of said multiplex / demultiplexing circuits, respectively. A plurality of multiplexing / demultiplexing circuit control units, a plurality of main highways connected to the plurality of multiplexing / demultiplexing circuits, and a connection to at least a part of the multiplex / demultiplexing circuits. A secondary highway, a communication path switch for switching connection between the primary highway and the secondary highway, and a request for allocation of a time slot on the secondary highway from the multiplexer / demultiplexing circuit controller connected to the secondary highway A sub-highway management unit for managing the above, based on information from the multiplexing / demultiplexing circuit control unit and the sub-highway management unit, A digital exchange comprising a demultiplexing / demultiplexing circuit control unit and a call processing unit for controlling a speech path switch, wherein the demultiplexing / demultiplexing circuit control unit is a sub highway if there is no empty time slot on the main highway. A digital exchange characterized by allocating a time slot on a sub highway managed by a management unit.