KR0174697B1 - Optical trunk interface circuit of switching system - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

It is a technology for interfacing to transmit and receive with optical signals between HOST, RSS, and RSM.

2. The technical problem to be solved by the invention

It implements optical trunk interface circuit that transmits large amount of data quickly when data communication between RMS, RSS and host.

3. Summary of Solution to Invention

Voice / IPC data receiving and optical transmission stage that receives subscriber's telephone channel data from analog line interface and spatial switching device and multiplexes it into 8-bit 256-channel data stream and carries IPC data and alan status information. Receives CMI II (Code Mark Inversion II) bit string converted to an electrical signal, extracts data and clock, extracts bit clock and frame, retimes the data with the extracted bit clock, and decodes the data into NRZ. Receiver and voice / IPC data transmission means.

4. Important uses of the invention

It is applied to the optical trunk interface circuit in the electronic exchange.

Description

Optical trunk interface circuit of switching system

1 is an optical trunk interface circuit according to the present invention.

The present invention relates to an optical trunk interface circuit of an exchange system, and more particularly, to an optical trunk interface circuit for interfacing to transmit and receive with an optical signal between a host (HOST), a RSS (Romote Subscriber Switch), and an RSSM (Romote Subscriber Module). It is about.

In general, the trunk device of the electronic switching system is connected to the optical station through the PCM cable by using the trunk board to the host (HOST), RSS and RSM. The optical station collects several PCM cables, converts them to optical, and sends them to the other optical station. In the case of a long distance, the signal is amplified by using an optical repeater in the middle and then sent.The other optical station receives this signal, converts it into an electrical signal, and sends it to the trunk circuit to supply PCM data and clock to RSM and RSS. .

However, the conventional RMS and RSS require an optical multiplexer device in a long distance to exchange data communication with a host, and in the case of a long distance, a PCM repeater is required even if a PCM cable is used. There is a risk of loss and a significant time delay occurs during transmission.

Accordingly, an object of the present invention is to provide an optical trunk interface circuit for quickly transmitting a large amount of data when data communication between the RMS and RSS and the host to solve the above problems.

Another object of the present invention is to provide an optical trunk interface circuit for interfacing transmit / receive data through an optical link between a host, an RSM, and an RSS.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is an optical trunk interface circuit diagram according to the present invention,

Voice / IPC data reception and optical transmission unit 10 for receiving subscriber telephone channel data from an analog line interface and a space switching device and multiplexing into 8-bit 256-channel data streams, carrying IPC data and alan state information, and

Receives CMI II (Code Mark Inversion II) bit stream converted from optical signal to electrical signal from wide dynamic, separates data and clock, extracts bit clock and frame, and retimes the data with the extracted bit clock. And an optical receiver and a voice / IPC data transmitter 20 for decoding with NRZ.

The operation of the preferred embodiment of the present invention will be described in detail with reference to FIG.

The first serial to parallel (S / P) converter 12 converts subscriber telephone channel serial data received from a digital line concentration division (DLCD) and a space switch division (SWCD) into parallel data and outputs the parallel data to the latch 13. . The reception clock generator 11 receives the frame synchronization signal FS and the reference clock of 4 MHz from the DDCD or the RCSB to generate a 16.384 MHz and synchronous clock signal by the internal PLL logic, and output it to the latch 13. The latch 13 latches the parallel data converted from the first S / P converter 12 by the clock signal generated from the clock generator 11. The second S / P converter 14 receives data from the RPB, converts the data into parallel data, and outputs the parallel data to the MUX 15. The timing generator 18 generates a timing signal and an NRZ data retiming signal for multiplexing and outputting. The MUX 15 inputs the parallel data output from the latch 13 and multiplexes the data into a 256-channel data stream of 8 bits from 0 timeslot to 255 timeslots. Data is inserted and multiplexed with alarm status information in 129 timeslots and outputted to the first P / S converter 16. The second P / S converter 16 converts the data multiplexed into 256 channels into serial data of 16.384 Mbps and outputs the serial data to the NRZ / CMI encoder 17. The NRZ / CMI encoder 17 converts the NRZ serial data of 16.384 Mbps into a CMI code and then uses three consecutive logic levels of 0 or 0, which deviates from the CMI II code theory by TTL logic to identify the frame start point. Insert one pattern into timeslots 0 and 1 and send. In the NRZ data column, the mark (MARK: 1 or logic: High) state is alternating, and the space (0: logic or low) state is logically matched with a clock pulse of 16.384 MHz, and then exclusively combined with the alternating mark state. Convert to CMI II. The converted data is transmitted to the optical signal transmitter composed of XMT3350 with the inserted Frame Aignment Word (FAW) in violation of the timeslot 0,1. At this time, the optical signal transmitter converts an electrical signal into an optical signal and transmits the optical signal to the other optical link interface board at -10 dbm.

In this way, when optical power is transmitted, the other optical signal receiver STZ-01-DC-ST (a wide dynamic range capable of receiving PINFET 0dbm to -47dbm) converts and outputs an optical signal to an electrical signal roll and outputs the optical signal receiver. Receiving the signal converted from the electrical signal from the RSM (RCSB) or RSS (SWCD) to demodulate the signal required for transmission to the RSM (RCSB) or RSS (SWCD) Looking at the operation, the data / clock extraction unit 21 After receiving the CMI II bit string signal, the data and the clock are separated and extracted, the bit clock and the frame are extracted by logic, and output to the CMI / NRZ decoder 22. The CMI / NRZ decoder 22 retimes the bit clock and data, decodes CMI II code data into NRZ data, extracts frame phase information, and then extracts frame phase information from the received bit stream based on the extracted frame phase information (RFP). The data is converted into 8-bit data in the time slot unit and then output to the stack buffer 23. The elastic buffer 23 records 8-bit data converted in time slot units in synchronization with a clock signal RCP3 of 2.048 MHz, and generates the recorded data from the timing generator 18. It reads sequentially and outputs to the DEMUX 24 according to the transmission timing. The DEMUX 24 demultiplexes the NRZ data read out from the stack buffer 23 and outputs the NRZ data to the second P / S converter 25 and the third P / S converter 26. The third P / S converter 26 converts the alarm data and the IPC data into serial data and transmits the serial data to the RPB. The second P / S converter 25 converts subscriber telephone channel data demultiplexed and output from the DEMUX 24 into serial data and transmits the serial data to RSS (SWCD) or RSM (RCSB).

As described above, the present invention uses an optical trunk to directly connect the optical fiber between the host and the RSS and RSM, so that a larger amount of data can be transmitted quickly and without data loss, and no repeats are used to reduce costs. There is an advantage to this.

Claims (4)

In the optical trunk interface circuit in a switching system, voice / IPC data reception is performed by receiving subscriber telephone channel data from an analog line interface and a space switching device and multiplexing them into 8-bit 256-channel data streams to carry IPC data and alan status information. And receiving the CMI II bit string converted from the optical signal to the electrical signal from the wide dynamic terminal, separating the data and the clock, extracting the bit clock and the frame, and retiming the data with the extracted bit clock to NRZ. An optical trunk interface circuit, comprising: an optical receiver and a voice / IPC data transmitting means for decoding. 2. The apparatus of claim 1, wherein the voice / IPC data receiving and optical transmitting stage comprises: a first S / P converter for converting subscriber telephone channel serial data received from the DLCD and the SWCD into parallel data, and a frame synchronization signal from the DDCD or RCSB. Receiving clock generation means for receiving a reference clock of FS) and 4 MHz and generating and outputting a 16.384 MHz and synchronous clock signal by an internal PLL logic, and generating the clock at the same time with the parallel data converted from the first S / P converter. A latch means for latching output by a clock signal generated from a negative portion, a second S / P converter for receiving data from the RPB, converting the data into parallel data, and outputting the parallel data outputted from the latching means to 0 time slots. Multiplexing means for multiplexing and outputting a 256-channel data stream of 8 bits from 255 timeslots, and serializing data multiplexed into 256 channels from the multiplexing means at 16.384 MHz A second P / S converter which converts and outputs the signal to the second, and 3 consecutive times that deviate from the CMI II code theory by TTL logic in order to identify the frame start point after converting the 16.384 Mbps NRZ serial data into a CMI code. And an NRZ / CMI encoder for inserting and transmitting a logic level 0 or 1 pattern in timeslots 0 and 1 into an optical trunk interface circuit. 3. The optical trunk interface circuit according to claim 2, wherein the multiplexing means inserts IPC data into 128 and 130 time slots in the data stream and multiplexes alarm status information in 129 time slots. [4] The data receiver of claim 3, wherein the optical receiver and the voice / IPC data transmitting means comprise: data / clock extracting means for receiving a CMI II bit string signal, extracting data and a clock, and extracting a bit clock and a frame by logic; Re-time the bit clock and the data, decode the CMI II code data into NRZ data, extract the frame phase information, and then, from the received bit stream to 8-bit data in time slot units, based on the extracted frame phase information (RFP). Since the CMI / NRZ decoder converts and outputs the 8-bit data converted in the time slot unit to the 2.048 MHz clock signal RCP3 in synchronization, and sequentially reads and outputs the recorded data according to the transmission timing. A demultiplexing means for demultiplexing the stack buffer, the NRZ data read out from the stack buffer, and outputting the demultiplexing means, and corresponding alarm data and IPC data. A third P / S converter converting the column data to the RPB and converting the subscriber telephone channel data demultiplexed and outputted from the demultiplexing means into serial data and transmitting the same to RSS (SWCD) or RSM (RCSB). Optical trunk interface circuit, characterized by consisting of 2 P / S converter.