KR0135542B1 - European line machine device - Google Patents

Abstract

The present invention relates to a European-type digital subscriber line matching device, which is an ISDN service using a European-style primary group digital relay transmission system by connecting a primary group multiple device that accepts local or remote digital subscribers with basic access to an exchange system. Provide ISDN service to subscribers who want to.

Description

European digital subscriber line matching device

1 is a block diagram of a European digital subscriber line matching device according to the present invention.

2 is a timing relationship diagram between clocks according to FIG. 1;

3 is a table for showing a B channel serial data format received from the voice switch unit according to FIG.

4 is a table showing channel assignments for a V4 interface on 2048 Mbps.

5 is a diagram showing a European multi-frame configuration.

＊ Explanation of symbols for main parts of drawing

10: synchronization generator 30: switch unit

40: PCM matching unit 50: HDLC control unit

60: address decoder section 100: processor section

110: common memory unit 120: memory unit

The present invention is to provide ISDN services to subscribers who want to receive ISDN (Integrated Information Communication Network) service, and in particular, a primary service that accepts local or remote digital subscribers as basic access using a European primary group digital relay transmission system. A European digital subscriber line matching device for connecting a military multiple device to a switching system.

An object of the present invention is to provide a service of a non-ISDN exchange when an existing exchange is operated mechanically and thus cannot add ISDN functionality or there are only a few subscribers who want ISDN services. In order to provide ISDN services to subscribers, remote devices, which are multiple devices that accept digital subscribers as basic access, are installed next to the non-ISDN switch to replace the services of these subscribers. In other words, the present invention provides a digital subscriber line matching device in charge of a function of accommodating a European type remote device in a switching system.

In order to achieve the above object, the present invention provides a synchronization matching unit, a voice switch unit, and a B for generating a predetermined synchronization signal by receiving a predetermined system frequency and a frame synchronization signal from a switching system in a digital subscriber line matching device of the European system. Switch unit for transmitting / receiving channel data, HDLC control unit for controlling and transmitting D, C channel data to switch unit, PCM matching for interfacing with multi subscriber matching unit and PCM conversion of switched B, C, D channel data The processor unit initializes each component and executes a control command, an address decoder unit generating a signal for controlling decoding and read / write mode of each unit's input / output according to a processor command, and a processor unit. Memory unit for storing programs and various data, and data necessary for communication with the upper processing unit A common memory for storing an interrupt processing, a packet processing unit, monitors the matching portion, it characterized in that it comprises an alarm detector.

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

1 is a block diagram of a European digital subscriber line matching device according to the present invention. Synchronization generator 10 and subscriber station equipment for generating Foi and 2.048 MHz signals to digital subscriber line matching device by receiving synchronization frequency (FS) and system frequency (4.096MHz) from voice switch unit 11 of the switching system. High-level data link control (HDLC) control processing 16Kbps D, C channels for communication between the communication network and 64Kbps B channel received from the voice switch unit 11 of the exchange system and HDLC control unit 50 Switch unit 30 for switching one D, C channel, PCM matching unit 40 for PCM conversion of the switched data, initializing each part of the device, processing the status of the device and giving control commands to other circuits. A processor unit 100 configured to perform the above, a memory unit 120 including an EPROM of 128 Kbytes for storing a program processed by the processor, and an SRAM of 256 KBytes for storing various data processed by the processor, and an upper processor unit 13. The common memory unit 110, which consists of a 4KByte dual port RAM that stores data for communication, and an address decoder that generates a signal for controlling decoding and read / write mode for each input and output according to a processor's command. A unit 60 includes a monitor matching unit 130 for connecting a monitor to the operator to test the apparatus or confirm the state, and a packet processing unit 90 for processing packet data.

In FIG. 1, the digital subscriber line matching device provided between the voice switch unit 11 of the exchange system and the multi-subscriber matching unit 12 of the European system is a European remote station (RT) and a European central control unit (COT). It handles the functions of the Link Access Procedure on D-channel (LAPD) protocol of Layer 1 and Layer 2 of the signaling method for interfacing between the controllers and performs communication with the European Central Control Unit (COT). The voice switch unit 11 transmits 16 B channel transmission data having a 2.048 Mbps signal rate to the switch unit 30, and the D and C channel data transmitted from the HDLC control unit 50 are transferred to the V4 interface at the switch unit 30. Switch to the PCM matching unit 40. The voice switch unit 11 transmits channel data and supplies a system clock of 4.096 MHz and a frame synchronization signal of 8 kHz to the synchronization generator 10, and the synchronization generator 10 supplies the switch unit 30. The system clock of 4.096 MHz and a predetermined synchronization signal Fo are supplied to perform error detection and channel separation for the D and C channel data transmitted and received to the switch unit 30. In addition, the switch unit 30 receives the D channel and C channel data from the HDLC control unit 50, and uses the 4.096 MHz clock and the transmit / receive data frame synchronization signals FRSø to FRS6 from the voice switch unit 11. The D and C channel data are processed and stored in the common memory unit 110 by a link access protocol on-D channel (LAPD) function, which is a protocol of Layer 2, which is a data link layer. The upper processor unit 13 reads data stored in the common memory unit 110 and controls layer 3 which is a network layer. In FIG. 1, the B channel interface 20 is connected to the voice switch unit 11 and the PCM sub highway so that one sub highway SW transmits and receives B channels for 12 basic accesses. The European subscriber line matching device handles 2B channels, i.e. 24 basic accesses.

2 is a diagram showing the timing between clocks of the European digital subscriber line matching device according to FIG. 1, (a) is a 4.096 MHz clock signal generated from the voice switch unit 11, and (b) is synchronization generation. 2.048 MHz clock signal generated from the unit 10 to the PCM matching unit 40, (c) is an 8 kHz frame synchronizing signal (FS) waveform generated from the voice switch unit 11, and (d) is a voice switch. Switch unit 30 as a synchronization signal (Foi) waveform for B channel data and D and C channel data transmission using the 4.096 MHz clock (a) and frame synchronization signal (FS; c) received from unit 11; And a signal supplied to the PCM matching unit 40. (e) shows a frame synchronous clock signal (FSC) waveform supplied to IDEC of the HDLC control unit 50 using a synchronization signal (Foi; d) for B, C, D channel data transmission.

3 illustrates the B channel serial data format received by the B channel interface unit 20 from the voice switch unit 11. One frame at 2.048Mbps has 32 channels, of which only 24 channels correspond to 12 basic accesses.

The switch unit 30 is a 256-point non blocking switch having an 8-line x 32-channel input and output structure and directly interfaces with the processor unit 100. The data stream received from the European multi-subscriber matching unit 12 to the switching unit 30 is switched to the HDLC control unit IDEC since the timeslots 5, 10, 15, 21, 26, and 31 are D and Cv channel data in the European system. The other data streams are switched to the voice switch unit 11 because they are B-channel data. The D and C channel data transmitted from the HDLC control unit 50 are switched to the V4 interface structure in the switch unit 30 and transmitted to the PCM matching unit 40. In FIG. 4, a transmission rate of 2.048 Mbps per frame is shown. It shows channel assignment for V4 interface of B, C, D channel data. As shown in FIG. 4, 24 channel timeslots of the 32 channel timeslots are used as B1 and B2 channels for 12 basic accesses, and D and Cv channels for each basic access are allocated to the remaining timeslots. Since the D and Cv channels for the two basic accesses are multiplexed into one time slot, only six timeslots are needed, and two basic accesses, each consisting of B1 + B2 + Cv + D channels, have five consecutive timeslots. Occupies.

PCM matching unit 40 is interfaced with the processor through the switch unit 30 is composed of a European-style trunk interface 41 and the line interface unit 42. The main functions of the trunk interface unit 41 include frame formatting and monitoring functions, alarm insertion and monitoring functions, clock and data recovery functions, and the like. The frame formatting and monitoring function sets the frames and multiframes as shown in FIG. 6 with respect to the data stream input from the switch unit 30, and transmits them to the power station when a frame and carrier loss alarm occurs, and serially formatted data. HDB3 encoding, which is a European transmission path code, is performed on the stream. Frame bits are extracted from the reproduced data stream to distinguish between frames and multiframes, and an error condition is performed. The alarm insertion and monitoring function sends out the European digital line from the transmitter according to the alarm detected by the receiver. Allows the processor to know the status of frame alarms, multiframe alarms, carrier loss, remote receive alarms, etc., and the number of occurrences of frame errors and slips. The clock and data recovery function receives data from the PCM trunk, performs bipolar / unipolar (B / U) conversion, and then extracts a 2.048 MHz clock from unipolar data.

The line interface unit 42 converts the formatted frame signal into a bipolar signal having a better transmission effect than the unipolar in order to transmit the formatted frame signal to the PCM relay line, and converts the bipolar signal input from the PCM relay line into a unipolar signal having a TTL level.

The B channel received from the voice switch unit 11 and the D channel data from the HDLC control unit 50 are assigned a time slot in the switch unit 30 and processed according to the ST bus (Serial Telecom-Bus) format. Switch to 40. The PCM matching unit 40 converts the B channel and the D channel into HDB3 encoding and CRC-4 multiframe structures, which are European transmission codes, and transmits them to the PCM line. The form of the multiframe structure is shown in FIG. 5, where channel 0 is basically used for line maintenance and channel 16 is used as a spare channel. The main function of the PCM matching unit 40 is to convert the B and D channels according to the European transmission method and transmit and receive them with the digital subscriber. The maintenance of the necessary lines in this process is performed through channel 0 and received from the other party. When there is frame alignment or CRC error in one signal, bit 3 of channel 0 of odd frame is set to '1' and sent to the other side, and valid data cannot be transmitted from this digital subscriber line matching device or there is a problem with the line. In case of testing, send all data corresponding to the previous frame as '1' to the other party. This maintenance-related behavior was controlled by the processor and made available for monitoring by the user.

Claims (1)

In the European digital subscriber line matching device, a synchronization generator for receiving a predetermined system frequency and a frame synchronization signal from a switching system and generating a predetermined synchronization signal, a switch for transmitting and receiving voice signals and B channel data. , HDLC control unit for controlling D, C channel data and transmitting to switch unit, PCM matching unit for interfacing with multi-subscriber matching unit and PCM conversion of switched B, C, D channel data, initializing each component and executing control command The processor unit to perform, the address decoder unit for generating a signal for controlling the decoding and read / write mode for each input and output according to the instructions of the processor, the memory unit for storing the program and various data to be executed in the processor unit And having a common memory unit for storing data necessary for communication with the upper processing unit European way digital subscriber line matching device according to claim.