JPH0785600B2 - Time division exchange system - Google Patents

Description

The present invention relates to a time-division exchange system for time-division exchange of voice, data, etc., and in particular, its control system and speech path system are both reliable as a completely distributed configuration. And a time-division exchange system that achieves high efficiency and economic efficiency.

[Conventional technology]

For a long time, a large-scale single processor with high processing capacity has been used as a control system for a time-division exchange, but such a single processor needs to be duplicated for reliability, so a large mounting area is required. It was extremely expensive.

In recent years, with the emergence of excellent and safe microprocessors due to the development of LSI technology, it has become mainstream to use a multiprocessor composed of a plurality of microprocessors as a control system of a time division switch.

However, the conventional multiprocessor system is, for example, one in which the function of one processor having a large processing capacity is simply realized by a plurality of microprocessors independently of the speech path system, or the building of the speech path system. The number of microprocessors was increased or decreased according to the block configuration.

In such a conventional example, since the communication path system is tightly coupled, the microprocessors are also tightly coupled. Therefore, even if the multiprocessors are function-distributed or load-distributed, the communication amount between the multiprocessors increases, which not only greatly affects the throughput and the processing capacity, but also when a failure occurs, There is a risk that the reliability of the system may be seriously affected depending on the mode. Further, since the memory for managing the communication path is generally placed in common for each processor, this portion becomes a bottleneck in view of reliability, especially in the case of a global broadcast.

[Object of the Invention]

It is an object of the present invention to provide a time-division switching system which eliminates the above-mentioned drawbacks of the prior art and can obtain reliability and economy as a completely distributed configuration for both the control system and the communication path system.

[Outline of Invention]

A configuration of a time division switching system according to the present invention has an independent exchange function including an interface section with an external line, a time switch for accommodating them by a time division multiplexing highway, and a control device for controlling them. And a second switching unit including a time switch and a controller for controlling the time switch, and the time switch of the first switching unit is connected to the time switches of two or more second switching units. A terminal for accommodating a highway is provided, and the time switch of the second exchange unit can accommodate a highway for connecting to two or more of the first exchange units, and two or more of the first exchange units and one or more of the first exchange units. The second switching units of the above are connected to each other only by a time division multiplexing highway, and a direct connection highway is provided between the first switching units. Is obtained by way not was.

In short, a complete group exchange system is configured with each independent local exchange unit that interfaces with various lines, each independent relay exchange unit, and the junction highway that connects between these units. The control channel makes it possible to exchange information and loosen the coupling between the units.

Example of Invention

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

FIG. 1 is a relay system diagram of an embodiment of a time division switching system according to the present invention, FIG. 2 is a format diagram of channel assignment of the highway, and FIG. 3 is a format diagram of the same polling channel pattern. FIG. 4 is a format diagram of channel allocation of the same junction highway, and FIG. 5 is a communication sequence diagram of the same connection.

Here, 10 is a local exchange unit (U # 1 to #p),
Reference numeral 11 denotes a terminal circuit for the analog or digital subscriber line, relay line, service line, and other various circuits L.
, 12 are interface circuits corresponding to the plurality of terminal circuits 11 (# 1 to # 1 for each group).
l) and 13 are also highways (HW # 1 to #m) in which a predetermined number (l of the interface circuit 12 is multiplexed and accommodated in the time switch 14), 15 is the same polling control circuit, 16 is the same bus, and 17 is the same. A processor, 20 is a relay exchange unit (T # 1
~ #Q), 21 is the time switch, 22 is the processing device,
Reference numeral 30 is a junction highway (JHW) that connects each local exchange unit 10 and relay exchange unit 20, and 40 is a normal network management unit including a memory and a processing unit, and the time of any one local exchange unit 10 It is housed in the switch 14.

First, a polling operation for detecting a state change in the line L (for example, calling a subscriber, receiving a call, transmitting / receiving a number, sending a charging pulse, restoring, etc., hereinafter referred to as an event occurrence) will be described.

The polling operation circuit 15 is, for example, as shown in FIG.
Predetermined specific highway 13 (eg # 1)
The identification information (for example, number) of the specific interface circuit 12 (for example, "1") is written in the frame # 0 and the channel # 0 at a cycle of 8 ms.

Channel # 0 on which this writing was performed is on the highway 13
After getting on (# 1) and exchanging time slots with the time switch 14, for example, as shown in FIG.
It is placed on the downlink channel # 1 of (# 1).

Since the interface circuit 12 (# 1) stores the number # 1 in advance, the interface circuit 12 (# 1) compares the number # 1 with the content (number) written in the channel # 1, and if they match, identifies itself as polling. To do.

When an event occurs in the interface circuit 12 (# 1), its own number (# 1) and a communication request to the processing device 17 are used as a polling response, and as shown in FIG. It is placed on the upstream channel # 1 of 1).

The upstream of the highway 13 (# 1) is exchanged by the time switch 14 and then connected to the polling control circuit 15 through the corresponding highway 13.

The polling control circuit 15 uses the third
A communication request from the interface circuit 12 (# 1) related to the highway 13 (# 1) to the processing device 17 is generated by forming a multi-frame in a channel pattern as shown in the figure or by storing the multi-frame in a first-in first-out memory. The presence is identified and the fact is notified to the processing device 17 via the bus 16.

The processing unit 17 uses, for example, as shown in FIG.
Interface circuit 12 (# 1) using 64-67
Communicate with.

With the above operation sequence, the service request received by the terminal circuit 11 can be transmitted to the processing device 17 via the interface circuit 12, and the processing corresponding to the event can be performed.

It should be noted that the above-mentioned polling channel may be plural if necessary.

Next, communication between the local exchange unit 10 and the relay exchange unit 20 will be described.

When the processing device 17 of the local switching unit 10 (eg # 1) determines that the call needs to be transmitted to another same unit (eg #p), the local switching unit 10 (#
1), using the junction highway 30 between the relay exchange unit 20 (for example, # 1) to specify the channel (set the communication channel for service),
As shown in the figure, through the channels # 64 to 67, the identification information of the destination local exchange unit 10 (#p) (for example, the number p)
And route number information to the relay switching unit 20 (# 1).

In this case, since the connection between each local exchange unit 10 and the relay exchange unit 20 is a perfect group exchange system as described above, which relay exchange unit 20 is selected may be arbitrary.

Based on the above information, the processing device 22 determines whether the time switch 21
The exchange control is performed, and the route number and the like are transmitted to the destination local exchange unit 10 (#p) via the junction highway 30, and the processing is entrusted.

Here, since the above-mentioned time switch 21 is a complete group and is configured to be non-blocking, there is no correspondence in the time slot between the entrance and exit of the junction highway 30, and therefore the time of the entrance side It can be replaced with an outgoing time slot that is independent of the slot. The same applies to the local exchange unit 10.

Further, the operation of the outgoing connection will be described.

When the call originated within the local switching unit 10 (eg # 1) itself is an outgoing connection (eg route # 1), the network management unit 40 accessible from each local switching unit 10 (# 1 to #p) (In FIG. 1, as an example, #
1) The local switching unit 10 (# 1) uses the specific channel of the junction highway 30 and the highway 13 to receive the outgoing connection information (for example, the called party) from the local switching unit 10 (# 1). Number) is sent.

As a result, as shown in FIG. 5 (a), the network management unit 40 identifies the route # 1 from the received called number, and separately, all the busy information for each route from each local exchange unit 10, Since the vacancy occurrence information is received and accumulated, the vacancy occurrence information is used to use the local exchange unit 10 (for example, #
p) and identify its number.

If there is no vacancy in the route # 1 (if all talks are in progress), detour processing is performed as necessary, another route number is extracted, and the local exchange unit 10 is specified in the same manner as above.

The network management unit 40 is a local switching unit
The required information on the route # 1 and the connection information to the unit #p are transmitted to 10 (# 1).

The local exchange unit 10 (# 1), in accordance with the method of transmitting and receiving information with the local exchange unit 10 and the relay exchange unit 20 described above, informs the relay exchange unit 20 of connection information to the local exchange unit 10 (#p). ， Route information (#
Send 1).

As a result, the relay exchange unit 20 makes a connection to the local exchange unit 10 (#p) and transmits the information of the route # 1.

The local exchange unit 10 (#p) makes a desired outgoing connection based on the information of the route # 1.

Before or after, only one network management unit 40 is installed for the system, and a fixed channel is allocated to the processing device 17 of each local switching unit.

When the network management unit 40 cannot be used due to a failure or the like, as shown in FIG. 5 (b), the local switching unit 10 (# 1), upon identifying this fact, sends to each local switching unit 10 of each route. The local exchange unit 10 (#p) accommodating the outgoing trunk of the route # 1 is selected and identified by the table indicating the accommodation status of the route # 1, and the connection to the local exchange unit 10 (#p) and transmission / reception of information are transmitted to the relay unit 20. A desired outgoing connection is realized by the above sequence.

In this case, not only can each local exchange unit 10 not know the availability of each route or the busy status of each route, but also detour processing cannot be performed. Or call loss will occur. But,
While a special condition such as a failure of the network management unit is equivalent to a system down in the conventional system, it is extremely possible that call communication can be achieved even if some service deterioration cannot be avoided. That is valid.

Finally, polling control circuit 17, interface circuit 1
2 will be described in more detail.

FIG. 6 is a block diagram of an embodiment of a polling control circuit of a time division switching system according to the present invention, in which (a) is for a main part of a polling transmission part and (b) is for polling response reception. To the main part of the department,
FIG. 7 is a block diagram of an interface circuit according to an embodiment of the present invention, which is for a main part relating to polling transmission / reception.

In FIG. 6 (a), the clock frequency dividing unit 100, which receives a clock and a frame pulse from the outside, creates a multi-layer clock and distributes it to each unit.

The counter 101 receives the above clock and counts,
A decoder 103 for expanding and decoding frame numbers and channel numbers of time-division multiplexed highway, a data creating circuit 104 for creating data to be inserted into a polling channel, and a parity generator 106 for adding a parity bit.
Send bit information to.

Information from the outside, for example, information on the operation mode (normal / standby or operation / stop) is written from the first-in-first-out memory 119 described later to the external information register 102.

The synchronization pattern at the beginning of the frame is created by the synchronization pattern generation circuit 105 and buffered by the buffer 107. The polling information and the mode designation information for the terminal are buffered in the buffer 108.

They are sent to the parallel-serial conversion circuit 109 in time for the timing of the sending channel and put on the highway 13 (HW) as serial data.

Next, FIG. 6 (b) will be described.

On the highway 13 (HW) in which the synchronization pattern is added to the data transmitted from the interface circuit 12, the time switch 14 switches to the highway 13 in which the polling control circuit 17 is accommodated.

From the highway 13, clocks, frame pulses, and serial data are input to the polling control circuit 17 by a device (not shown).

The clock frequency dividing circuit 100 (described above) creates a multi-layer clock from the clock and the frame pulse, and distributes it to each necessary unit.

Serial-to-parallel converter circuit 110A for receiving highway serial data
Are converted into parallel data by, and the synchronization pattern is identified by the synchronization identification circuit 113. After establishing synchronization, another serial-parallel conversion circuit 1
Data check circuit for polling response data at 10B 11
6, Send to parity generator 117, encoder 118.

After checking the data, if the data is correct, it is written in the first-in first-out memory 119. The software is
By periodically reading the contents of the memory 119 via the bus 16, it is possible to know which interface circuit 12 requests communication.

Further, in FIG. 7, the data transmitted from the polling control circuit 15 is switched to the highway 13 in which the corresponding interface circuit 12 is accommodated by the time switch 14, and the synchronization pattern at the beginning of the frame is Although not shown, it is identified before input to the interface circuit 12, and the clock, frame pulse, and highway serial data are input to the interface circuit 12. Also, the synchronization pattern of the transmission highway is added by another device (not shown).

The clock frequency dividing circuit 121 creates a necessary multi-layer clock in the interface circuit 12 from the clock and the frame pulse, and distributes it to each unit (not shown).

The serial-parallel conversion circuit 122 causes the decoder 124 to decode the operation mode in the received serial data, and, for example, the general operation mode (online state), the test mode,
The maintenance operation mode is identified. Also, the decoder 125
Develops polling information and identifies whether or not it is its own number (whether its own interface circuit 12 requires communication with the processing device 17).

When communication with the processing device 17 is required, the fact is written from the processor 120 to the register 126 for polling response information. Therefore, in the general operation mode, the buffer 128A is used.
Buffer to. In the test mode, if a fixed pattern is returned for the test, the pattern buffered in the buffer 128B is sent to the highway 13 in the test mode. In the maintenance / operation mode, for example, if maintenance scan-like information is externally written in the register 127, the content is buffered in the buffer 128C.

The contents buffered in the buffers 128A, 128B, 128C are parallel-serial conversion circuits so that they can be delivered in time.
It is sent to 129 and put on the highway 13 as serial data.

Here, the identification of the synchronization pattern at the time of reception, the extraction of the clock and the frame pulse, the addition of the synchronization pattern at the time of the transmission, and the superposition of the clock and the frame pulse are performed by a device (not shown).
Even if you go inside, there is no essential difference.

Although the respective examples have been assumed above for the sake of convenience of description, it is obvious that this does not hinder the generality of the present invention. Further, although the description of the same parts as the known technology such as the connection within the own station and the incoming connection is omitted, this also does not limit the present invention.

〔The invention's effect〕

As described above in detail, according to the present invention, both the control system and the communication path system can be fully distributed, and the mutual connection can be loosely coupled. Therefore, the reliability and economic efficiency of the time division switching system can be improved. A significant effect can be obtained in improving

[Brief description of drawings]

FIG. 1 is a relay system diagram of an embodiment of a time division switching system according to the present invention, FIG. 2 is a format diagram of channel allocation of the highway, and FIG. 3 is a format diagram of the polling channel pattern. FIG. 4 is a format diagram of channel allocation of the junction highway, FIG. 5 is a communication sequence diagram of the same connection, FIG. 6 is a block diagram of an embodiment of the polling control circuit, and FIG. It is a block diagram of one example of the interface circuit. 10 ... Local switching unit, 11 ... Terminal circuit, 12 ... Interface circuit, 13 ... Highway, 14 ... Time switch, 15 ... Polling control circuit, 16 ... Bus, 17 ... Processor, 20 ... … Relay switching unit, 21 …… Time switch, 22 …… Processing device, 30 …… Junkta highway, 40 …… Network management unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kuwahara 1-280 Higashi Koikekubo, Kokubunji, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Inventor Eiichi Amada 1-280 Higashi Koikeku, Kokubunji, Tokyo Hitachi Ltd. Central Research Laboratory (56) References JP-A-56-103590 (JP, A) JP-A-55-156494 (JP, A)

Claims (4)

[Claims] 1. A first switching unit having an independent switching function, which comprises an interface unit with an external line, a time switch for accommodating them by a time division multiplexing highway, and a control device for controlling them, and a time switch. And a controller for controlling the same, and a second exchange unit is provided, and the time switch of the first exchange unit is provided with a terminal for accommodating a highway for connecting to two or more time switches of the second exchange unit. , A time switch of the second exchange unit is capable of accommodating a highway for connection with two or more of the first exchange units, two or more of the first exchange units and one or more of the second exchange units. Are connected to each other by a time division multiplexing highway so that there is no direct connection highway between the first switching units. Both the second switching unit and the second switching unit communicate with each other, and at the time of call setup, the second switching unit receives the first switching unit number of the receiving side from the first switching unit of the calling side. A free time slot for an interconnection time division highway with the first switching unit is selected, and an interconnection highway with the destination first switching unit also designated by the originating first switching unit. While controlling and connecting the time slot and the switch of the receiving side, at the same time, the receiving side receives the auxiliary information necessary for the exchange operation in the receiving side first switching unit which is received from the calling side first switching unit. To the first switching unit, and at the end of the call, the switch is cut off by a command from the calling side or the called side, and signals are transferred only to the mutual communication between the calling side and the called side. First exchange The unit has a network management function that manages the state of resources related to the line to the other station accommodated in the plurality of first switching units and the detour routing, and the calling side that handles the outgoing connection call to the other station. The first switching unit has an arbitrary second switching function for the first switching unit having the network management function when setting up a call.
The first switching unit having the network management function determines the first switching unit number having a vacant line based on the information by accessing through the switching unit of The time-sharing exchange system is characterized in that the exchange unit of (1) starts the call setup operation by the returned number. 2. The time division switching system according to claim 1, wherein the first switching unit having the network management function has neither a line interface with the outside nor a switching function. 3. Each of the first exchange units communicates via the first exchange unit having the network management function in response to occurrence of a busy state or a state corresponding to each output path accommodated in its own unit, The first switching unit having the network management function is provided with an information display table for each first switching unit and for each outgoing route based on the information, thereby determining the first switching unit having an idle line. A time-division exchange system according to claim 1. 4. Each of the first exchange units stores an outgoing route accommodation situation to another station for each first exchange unit, and the first exchange unit having the network management function cannot be used. At this time, the first exchange unit on the receiving side is determined based on the accommodation information, and the call setting operation is performed. When the first exchange unit on the receiving side encounters all the talks of the desired route, the information is referred to as the first information. It is received via the second switching unit and the previous call setting operation is cleared, and the other receiving side first
4. The time division exchange system according to claim 3, wherein the exchange unit is determined and the retry is performed.