KR940006744B1 - Synchronous clock distributing apparatus of full electronics exchange - Google Patents

Abstract

The synchronizing clock distribution apparatus comprises a first electric line for distributing a space switch clock and an 8 KHz synchronizing signal to a space switch from a network synchronizing unit, a first optical fiber for distributing a sum signal of a system basic clock and the 8 KHz synchronizing signal to a central data matching unit from the network synchronizing unit, a second optical fiber line for distributing the system basic clock and the synchronizing signal to a local data matching unit from the central data matching unit, and a second electric line for distributing a time switch clock to a time switch from the local data matching unit, thereby improving the reliability of an electric switching system.

Description

Synchronous Clock Distribution Device for Electronic Switching System

1 is a block diagram of a clock distribution apparatus of a conventional all-electronic exchange.

2 is a configuration diagram of an electronic exchanger.

3 is a configuration diagram of a synchronous clock distribution device according to the present invention.

* Explanation of symbols for the main parts of the drawings

1,10: Synchronous device 2,20: Space switch

3,30: time switch 4: central data matching device

5: local data matching device 6,60: line matching device

7: service unit 11, 21, 51: electric wire

13,41: fiber optic line 61: subscriber matching device

62: digital trunk matching device 621: digital track

80: digital concentrator 101: clock line

401 data line

The present invention relates to a synchronous clock distribution device for distributing a clock in a synchronous state in an all-electronic exchange.

1 is a configuration diagram of a clock distribution device of a conventional electronic switch, 10 is a network device, 20 is a space switch, 30 is a time switch, 60 is a rotation matching device, 80 is a digital concentrator, 101 is a clock line, 401 Represents a data line, respectively.

Conventionally, as shown in FIG. 1, a high frequency system clock and synchronization are performed by the wires 101 from the network synchronizer 10 to the space switch 20, the time switch 30, and the digital concentrator 80, respectively. The signal was sent. In this case, transmission and reception data between the time switch 30 and the digital concentrator 80 is transmitted through the data line 401, and the clock is used by receiving the clock from the network synchronizer 10 through the clock line 101. It was. At this time, there may be a problem such as phase mismatch between the receiving end due to the difference of delay characteristics of the clock electrical preference. As the frequency of the clock increases, it is distorted by noise, and the exchange capacity of the electronic switch increases. 80) increases, the longer the electric line of the clock, the longer the length of the line becomes more attenuated signal, making the design of the receiver difficult and complicated. Therefore, in this case, if the distance is over a certain distance, the frequency can no longer be increased.

Accordingly, an object of the present invention is to provide a synchronous clock distribution device for performing switching by efficiently distributing a synchronous clock synchronized with an input and output reference clock of a synchronous network in an all-electronic exchange.

To achieve the above object, the present invention provides a network synchronizing device, a space switch connected to the network synchronizing device, a central data matching device connected to the space switch, a local data matching device connected to the central data matching device, and the local data matching device. A synchronous clock distribution device of an electronic switching system comprising a connected time switch and a subscriber matching device and a digital trunk matching device connected to the time switch, the synchronous clock distribution device comprising: a space switch clock and an 8 kHz synchronization signal from the network synchronizer to the space switch; A first fiber for distributing a first optical fiber line for distributing a signal obtained by synthesizing a system basic clock and an 8KHz synchronization signal from the network synchronizer to the central data matching device, and a system data from the central data matching device to a local data matching device; Second optical island for distributing clock and synchronization signal And a second wire for distributing the time switch clock from the local data matching device to the time switch in the local data matching device.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

2 is a schematic diagram of an electronic switch, 1 is a network synchronizer, 2 is a space switch, 3 is a time switch, 4 is a matcher data matcher, 5 is a local data matcher, 6 is a rotation matcher, and 7 is a service. Represents each unit.

Referring to the structure of the electronic switchboard in the form of a 'time switch (T) -space switch (S) -time switch (T) switch network', which is the object of the present invention, the electronic switch is divided into a switch network as shown in FIG. , Rotation matching device 6, service unit 7 and control system. The operation principle may be that data input from the circuit matching device 6 is exchanged in a switch network, connected to an appropriate line, and data is sent. At this time, the service unit 7 performs a signal processing function for smooth exchange and connection, and all these operations are controlled by the control system.

The switch network consists of a network starter (l), a space switch (2), a time switch (3), and an inter-switch matching device (4, 5). The inter-switch matching device is again connected to the central data matching device (4). And a data matching device 5. The circuit matching device 6 is composed of a subscriber matching device and a relay line matching device, and is connected to the service unit 7. The control system forms a separate network.

In order for the all-electronic exchange shown in FIG. 1 to operate in a synchronous state without generating slip in a network, a synchronous clock distribution device according to the present invention should be used.

That is, the network starter value 1 generates a clock synchronized with the synchronization reference clock input from the network, and transmits the synchronization signal and the operation clock to the space switch 2 and the central data matching device 4.

3 is a block diagram of a synchronous clock distribution apparatus according to the present invention, 1 is a network synchronizer, 2 is a space switch, 3 is a time switch, 4 is a central data matching device, 5 is a local data matching device, 7 is a signaling device, 11 and 12 represent an electric wire, 13 an optical fiber line, 41 an optical fiber line, 51 an electric wire, 61 a subscriber matching device, 62 a digital trunk matching device, and 621 a digital line.

In the synchronous clock distribution device according to the present invention, as shown in FIG. 3, the space switch 2 is connected to the network synchronizer device 1 via a wire 12, and the space switch 2 and the network synchronizer device ( 1) connect the central data matching device 4 to the central data matching device 4 through the optical fiber line 13, and connect the local data matching device 5 to the central data matching device 4 via the optical fiber line 41, The time switch 3 is connected to the data matching device 5 via a wire 51, and the signal device 7, the subscriber matching device 61, and the digital trunk matching device (the service unit) are connected to the time switch 3. 62) to connect.

When the relay line data of the host station is input from the digital line 621 to the digital trunk matching device 62 of the electronic switchboard, the synchronization reference clock is extracted and sent to the network device l through the wire 11 to the network synchronizer device. In (1), a phase-locked clock is generated by a phase-locked loop that takes this clock as an input, and this clock is supplied to the data transmission clock to the switch clock and digital network of the switch network.

In detail, the network synchronizer 1 generates a clock synchronized with a synchronization reference clock input through the transmission line 11 from an external network, and the clock is converted into a space switch 2 and an inter-switch matching device 4 and 5. send. The clock supplied from the network synchronizer 1 to the space switch 2 is a space switch clock of 16.384 MHz and an 8 KHz synchronous signal and is distributed through respective coin line transmission lines 12. The clock supplied from the network synchronizer device 1 to the inter-switch matching devices 4 and 5 is synthesized with a high frequency clock of 65.536 MHz, which is the system basic clock, and a synchronization signal of 8 Hz, thereby combining one wire in the form of one synthesized clock ( 13) is distributed to the central data matching device (4) using a fiber optic line as a transmission medium. The space switch 2 transmits data at a speed of 65.536 Mbps to the optical fiber line 41 through the central data matching device 4, which is an inter-switch matching device.

The local data matching device 5 reproduces the 65.536 MHz basic clock and the 8 KHz synchronous signal from the data string input from the optical fiber line 41 to generate a frequency necessary for switching at this clock, thereby generating a time switch through the wire 51. 3) to distribute.

The time switch clock distributed to the time switch 3 is an 8.192 MHz signal. In addition, the local data matching device 5 distributes the synchronization signal generated from the clock extracted from the data stream to the subscriber matching device 61 and the digital trunk matching device 62, which are rotation matching devices, through the time switch 3, and services. It is distributed to the signal device (7) which is a unit.

The digital trunk matching device 62 has a T1 method and a CEPT method. The 1.544 MHz transmission clock required by the T1 method uses a clock generated by inputting a synchronization signal as a PLL. 2.048MHz required by the CEPT method uses the clock divided by the time switch 3 as a transmission clock.

As such, the clock output from the network synchronizer 1 is supplied to the switch network, the subscriber circuit, and the relay line device so that the electronic switch is operated in synchronization with the network synchronizer clock.

In one embodiment of the present invention, the input reference clock 11 of the network synchronizer 1 accepts a maximum of three lines with a clock of 1.4444 MHz or 2.048 MHz, and one of them is selected and used for the network synchronizer.

In addition, when the high frequency electric signal is transmitted through the wire by the optical signal by the optical fiber line 13, the synthetic clock of the 65.536 MHz clock and the 8KHz synchronous signal sent from the network synchronizer 1 to the central data matching device 4 is transmitted. It solves the problems of noise, distortion, and signal attenuation, and improves the synchronization signal mismatch due to the electrical signal delay characteristics of wires over distance.

In one embodiment of the present invention, the optical fiber line 13, which transmits the clock from the network synchronizer 1 to the central data matching device 4, is duplicated in a total of 16 lines, and the clock in which the number of packages varies depending on the capacity of the electronic exchanger. Satisfy the demand.

In addition, a transmission line 12 for transmitting a clock distributed from the network synchronizer 1 to the space switch 2 and an optical fiber line for transmitting a clock distributed from the central data matching device 4 to the local data matching device 5 ( 41) was duplicated to prepare for failure of the clock distribution line. This is to increase the reliability of the electronic exchanger that exchanges data.

The present invention configured and operated as described above has an application effect that can improve the reliability of all electronic switchboards by losslessly switching and transmitting data inputted and outputted when connected to other exchangers in a communication network and switching the subscriber's call without loss. have.

Claims (5)

A network synchronizer 1, a space switch 2 connected to the network synchronizer 1, a central data matching device 4 connected to the space switch 2, and local data connected to the central data matching device 4 A matching device 5, a time switch 3 connected to the local data matching device 5, and a subscriber matching device 61 and a digital trunk matching device 62 connected to the time switch 3. A synchronous clock distribution apparatus of an all-electronic exchange; A first wire (12) for distributing a space switch clock and an 8 KHz synchronization signal from the network synchronizer (1) to the space switch (2), and the system from the network synchronizer (1) to the central data matching device (4) A first optical fiber line 13 for distributing a signal synthesized with a basic clock and an 8 kHz synchronization signal, and a second optical fiber for distributing a system basic clock and synchronization signal from the central data matching device 4 to a local data matching device 5; And a second wire (51) for distributing a time switch clock from said local data matching device (5) to a time switch (3). 2. The apparatus of claim 1, wherein the space switch clock is at a frequency of 16.384 MHz. The apparatus of claim 1, wherein the system base clock is at a frequency of 65.536 MHz. 2. The synchronous clock distribution device of claim 1, wherein the time switch clock has a frequency of 8.192 MHz. 2. The synchronous clock distribution device according to claim 1, wherein the first and second wires (12, 51) and the first and second optical fiber lines (13, 41) are duplexed.