KR20010019616A - a STM-1 Interfacing Circuit in the Switching System - Google Patents

Abstract

PURPOSE: The STM-1(Synchronous Transfer Mode-1) class circuit in a switching system is provided to offer an interface with automatic recognition, even though any link of an optic fiber and a UTP5(Unshielded Twisted Pair5) cable, supporting a STM-1 class data transfer speed, is connected. CONSTITUTION: The STM-1 class circuit in a switching system is provided with an RJ-45 connector(21), a transformer(22), a line coding device(23), an optic transceiver(24), a selection block(25) and a SONET(Synchronous Optic NETwork) framer(26). The RJ-45 connector(21), connected to a UTP5 cable, generates a link injection signal according to a connection state with the UTP5 cable and supplies it to the selection block(25). The selection block(25), according to the link injection signal supplied from the RJ-45 connector(21), connects the line coding device(23) and the SONET framer(26) so that the operation of a UTP5 interface domain can be executed or connects the optic transceiver(24) and the SONET framer(26) so that operation of an optical interface domain can be executed.

Description

STM-1 Interfacing Circuit in the Switching System

The present invention relates to an STM-1 interface circuit in an exchange system, and more particularly, to an STM-1 interface circuit in an exchange system that automatically recognizes a type of a linked link to provide an interface.

In general, UTP5 cable (Unshielded Twisted Pair 5 Cable) and optical fiber were used as transmission media supporting the STM-1 data rate.

However, UTP5 cable is used for short distances of less than 100 (m) due to the distance between the two nodes and the installation cost, and the optical fiber is used for the longer distance. Therefore, when developing a system in which the connection distance between two nodes is variable, a board must be developed separately for each link.

When using the UTP5 cable as a transmission medium, the interface circuit configuration is shown in Figure 1 (a), the RJ-45 connector 11 for transmitting and receiving data through the UTP5 cable, and the corresponding RJ-45 connector ( 11) a transformer 12 for converting the type of data applied through the line, a line coding device 13 for coding data applied from the transformer 12, and an ECL level through the line coding device 13; It includes a SONET framer 14 for sending and receiving signals (Emitter Coupled Logic Level Signal).

When the optical fiber is used as a transmission medium, the interface circuit configuration is shown in FIG. 1B through an optical transceiver 15 for transmitting and receiving data through the optical fiber and the optical transceiver 15. And a SONET framer 16 that sends and receives ECL level signals.

Here, the RJ-45 connector 11 is connected to the UTP5 cable, the UTP5 cable supports a data transfer rate of STM-1 class in a short distance of about 100 (m). However, at a distance of 100 m or more, a regenerator or an optical fiber is used to be connected to the optical transceiver 15. That is, when the distance between two nodes is short, the circuit of FIG. 1 (a), which is a board for interfacing UTP5 cable, is used for economical advantage, and in the long distance, the board for optical fiber is interfaced to increase reliability. (B) Use a circuit.

When using the UTP5 cable as a transmission medium, an ECL level signal is used between the line coding device 13 and the SONET framer 14, which is directed toward the SONET framer 14. Transmits a differential signal of a received +/- 'and a carrier detect signal, and the SONET framer 14 transmits a differential signal of' transmitted +/- 'toward the line coding device 13. Will be sent.

When the optical fiber is used as the transmission medium, an ECL level signal is used as in the case where the UTP5 cable is used as the transmission medium between the optical transceiver 15 and the SONET framer 16.

However, in the conventional exchange system, both types of boards, such as an optical fiber interface board and an UTP5 cable interface board, have to be developed according to the distance between two nodes performing STM-1 data transmission, thereby extending and developing the development period. There has been an increase in costs and difficulties in managing and updating.

The present invention relates to an interface circuit for solving the above-described problems, and to automatically recognize any link between an optical fiber and a UTP5 cable, which is a medium supporting the STM-1 data transmission rate, to provide an interface. An object of the present invention is to implement an STM-1 interface providing circuit by automatic one-link recognition.

1 is a block diagram showing a Synchronous Transfer Mode-1 (STM-1) class interface circuit in a conventional exchange system.

2 is a block diagram showing an STM-1 interface circuit in an exchange system according to an embodiment of the present invention;

FIG. 3 is a view illustrating a link injection signal in FIG. 2.

Explanation of symbols on the main parts of the drawings

21, 21-1, 21-2: RJ-45 connector

22: Transformer

23: line coding device

24: Optical Transceiver

25: Selection Block

26. SONET Framer (Synchronous Optic Network Framer)

The present invention for achieving the above object is a transformer for converting the form of data through the UTP5 cable, a line coding device for coding the data through the transformer, and an optical transceiver for converting the form of data through the optical fiber And an STM-1 interface circuit in an exchange system having a SONET framer that exchanges an ECL level signal with a corresponding line coding device or an optical transceiver, wherein the link generation signal is generated according to whether the UTP5 cable is connected. 45 connectors; And a selection block connecting the line coding device and the SONET framer or the optical transceiver and the SONET framer according to a link injection signal generated by the RJ-45 connector.

Here, the link injection signal is characterized in that the ground pin of the other side RJ-45 connector is pulled up so that the link injection signal is recognized as a 'high' level signal.

In the present invention, since both the UTP5 cable interface portion and the optical fiber interface portion transmit and receive the same signal in the ECL form with the system interface portion, the corresponding UTP5 cable interface portion and the optical fiber interface portion must be provided in one board, and from the RJ-45 connector. By receiving a signal indicating the connection status of the link to select the type of interface, it automatically recognizes which link between the fiber and the UTP5 cable is connected to provide an interface. Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the switching system according to the embodiment of the present invention, the STM-1 class interface circuit, as shown in FIG. 2, has an RJ-45 connector 21, a transformer 22, a line coding device 23, and an optical transceiver. (24), selection block (25), and SONET framer (26). Here, the transformer 22, the line coding device 23, the optical transceiver 24, and the SONET framer 26 are the same as in the conventional configuration, and thus description thereof is omitted.

The RJ-45 connector 21 is connected to a UTP5 cable. The RJ-45 connector 21 generates a link injection signal according to whether or not the UTP5 cable is connected or connected to the selection block 25.

The selection block 25 connects the line coding device 23 and the SONET framer 26 according to a link injection signal applied from the RJ-45 connector 21 to allow the UTP5 interface region to perform an operation or the The optical transceiver 24 and the SONET framer 26 are coupled to allow the fiber interface region to perform operation.

Referring to the operation of the STM-1 interface circuit in the exchange system according to the embodiment of the present invention configured as described above are as follows.

The most essential part of the present invention is the selection block 25 shown in Fig. 2, which is applied to the line coding device 23 of the UTP5 interface region and the optical transceiver 24 of the optical fiber interface region. It is connected at the same time so as to transmit and receive the SOCL framer 26 and the ECL level signal.

In particular, unlike the optical fiber interface region, the link injection signal obtained from the RJ-45 connector 21 of the UTP5 interface region may indicate whether a transmission medium is connected. Recognizing a CD signal indicating that there is a signal, it is checked whether there is a link injection signal applied from the corresponding RJ-45 connector 21.

At this time, when the link injection signal is recognized, only the UTP5 interface region is operated since the currently connected transmission medium is a UTP5 cable, and the transmission signal transmitted from the SONET framer 26 is connected to the corresponding UTP5 interface region. give.

On the other hand, when the link injection signal is not recognized, only the optical fiber interface region is operated since the currently connected transmission medium is an optical fiber, and the transmission signal transmitted from the SONET framer 26 is transmitted to the optical fiber interface region. Connect with

The link injection signal informs the link connection state by using a ground pin (GND) of the RJ-45 connector 21. The connection diagram is shown in FIG.

For example, if you make a pull-up on the No. 4 ground pin (GND) of the A-point RJ-45 connector 21-1, you can connect the B-point RJ-45 connector at the time of link connection. The 5th link injection signal in (21-2) recognizes a signal of 'high' level (+ 5V) rather than ground. If pull-up is made on the No. 4 ground pin (GND) of the RJ-45 connector (21-2) of the B point like this, when the link is connected, the 5th link of the RJ-45 connector (21-1) of the A point is connected. A high level (+ 5V) signal is detected on the injection signal, not ground, so the link point can be seen at the A point. Here, the corresponding pullup is to connect a resistor of an appropriate value to an arbitrary pin so that it is connected to a power supply so that a high-level power supply value is input whenever there is no input value on the pin.

As described above, the optical fiber and the UTP5 cable can be selectively used according to the present invention, so that two types of boards do not need to be developed according to the corresponding link, so that the development period can be shortened and the development cost can be reduced, and the efficiency of the board can be increased. When the board needs to be improved, the improvement of the board interface by link occurs only by the enhancement of the system interface area after the selection block, thereby increasing the convenience of managing and improving the board.

Claims (2)

A transformer for converting the shape of the data over the UTP5 cable, a line coding device for coding the data over the transformer, an optical transceiver for converting the shape of the data over the optical fiber, and a corresponding line coding device or optical transceiver with an ECL level In an STM-1 interface circuit in an exchange system having a SONET framer for sending and receiving a signal, An RJ-45 connector for generating a link injection signal according to whether the UTP5 cable is connected; And a selection block for connecting the line coding device and the SONET framer or the optical transceiver and the SONET framer according to a link injection signal generated by the RJ-45 connector. Interface circuit. The method of claim 1, The link injection signal pulls up the ground pin of the other side RJ-45 connector so that it is recognized as a 'high' level signal when the link connection, Estim-1 class interface circuit in the exchange system.