KR20000074035A - V5 protocol converter and ISDN network connection method using the same - Google Patents

Abstract

PURPOSE: A V5 protocol converter and an ISDN connecting method using the same are provided, which allows a local switch to which IDLC(integrated digital loop carrier) function of a network proprietor is applied to be able to accommodate channels of remote subscribers having no IDLC function. CONSTITUTION: In an apparatus for digital network connection between DLC(digital loop carrier) mode remote subscriber terminals and IDLC mode local switch, a V5 protocol converter includes means, connected between a local switch and subscriber terminals through E1 trunk, for converting DLC signal transmitted from a subscriber terminal into a protocol suitable for the local switch, and for converting IDLC signal sent from the local switch into a protocol suitable for the subscriber terminal.

Description

V5 protocol converter and ISDN network connection method using the same}

The present invention relates to a V5 protocol converter and an ISDN network access method using the same. More particularly, the present invention provides a method for accommodating most existing remote subscriber channel units without an IDLC in a local exchange to which an IDLC function of a network service provider is applied. The present invention relates to a V5 protocol converter and an ISDN network access method using the same.

The local exchange installed in the existing network service provider (Hankook Telecom) side accepts subscribers mainly using Digital Loop Carrier (DLC) using Fiber Loop Carrier (FLC), a transmission network technology. It was. Optical Subscriber Transmitter (FLC) is a 155Mbps optical subscriber transmitter developed by Korea Telecom (KT), which enables line management, self-diagnosis, remote control, and remote maintenance of high-speed information and communication networks. In addition, the network can be configured in a variety of ways, and two fiber strands of optical fiber to transmit 1890 lines to provide high-quality services. FIG. 1 illustrates a network diagram connecting ISDN BRI subscriber channel units by DLC using the FLC transmission network technology.

1 is a block diagram illustrating a general digital network access apparatus using a DLC scheme, wherein a local exchange 10 is provided on a network service provider side, and a central office terminal (COT) 20 and a remote terminal on a remote subscriber side. Remote Terminal (RT) 30 and an ISDN BRI Subscriber Terminal 40 are provided. The local exchange 10 and the central station terminal 20 are networked by matching each other through digital subscriber matching devices 11 and 21, respectively. The central station (COT) 20 and the remote terminal (RT) 30 are matched with each other through each of the E1 relay line matching devices 22 and 31 to form a network. The remote terminal (RT) 30 and the ISDN BRI subscriber terminal 40 match each other through digital subscriber matching devices 32 and 41 to form a network. Here, the digital subscriber matching devices 11, 21, 32, and 41 are connected to each other via a U interface, and have a speed of 160 Kbps per port. In other words, two 64Kbps (B) channels, one 16Kbps data (D) channel, and a 4Kbps port control signal and a 12Kbps synchronization signal are transmitted and received. One U interface basic frame consists of 18 bits of sync signal, 12 2B + D channels, and 6 bits of port control signal, for a total of 240 (= 18 + 12 × (16 + 2) + 6) It is composed of bits and transmits and requires 1.5ms of processing time. In addition, a port control signal of one port is composed of a total of 48 bits, and a total of eight basic frames are required. Therefore, one U interface super frame is composed of eight basic frames and a processing time of 12 ms is required. In addition, between the E1 relay line matching devices (22, 31) is connected to the 3DS0 E1 relay line, the 2B channel received from the local exchange 10 or ISDN BRI subscriber terminal 40 through the U interface as it is the corresponding channel of the E1 relay line Switch to The 3DS0 method allocates two B-channels and one D-channel with 64Kbps of digital signal per ISDN subscriber, and controls the ISDN subscriber's unused bits among the D-channels. It is used as data for 2), and it is composed of PCM format of 2B + D +. And in order to transmit the information of the port received for 12ms through the multiplexed E1 relay line (2048Kbps), total 96 E1 frames are required (125ns × 96 = 12ms), and the 48-bit port control signal of the 96 frames is D + channel. In order to transmit / receive using one bit, the channel unit processing modules 23 and 33 of the central station terminal 20 and the remote terminal 30 respectively insert a dummy value between the port control signals. Here, the dummy signal is set to "1" for the first 1 bit and 47 bits for the next one for synchronization. 2 bits of the D channel and 1 bit of the port control signal including the dummy signal are transmitted and received through the D + channel, and the data of the D + channel 2, which is a link access procedure on the D channel (LAPD) message, is received. The bit is switched to the D channel of the U interface as it is, and when the transition occurs, the port control signal of the U interface is set by setting the port control signal of the U interface 10 or the digital matching device 11 of the ISDN BRI subscriber station 40. Or 41). Here, the LAPD refers to a transmission control procedure proposed for an ISDN connection or a high density integrated circuit (LSI) chip therefor in the old CCITT recommendation I series for a 2B + D channel.

However, the above-described conventional digital network access apparatus using the DLC method includes a local exchange at the network service provider side, a central subscriber station (COT) and a remote terminal (RT) at the remote subscriber side to accommodate one subscriber port. Each matching device with a 1: 1 match is required. As a result, many maintenance costs are incurred, and many sections are provided for one service, and thus, there are many defects in improving quality of service.

Therefore, in recent years, IDLC (Integrated Digital Loop Carrier) function has been developed to apply IDLC method instead of DLC method in local exchange. This is because of the significant cost savings and excellent service quality. Accordingly, FLC, a transmission network technology, is gradually developing an IDLC function and spreading the FLC device to which the function is applied. In this way, the local exchange adopting the IDLC function is intended to accept the remote subscriber through the new LCC with the IDLC function.

However, although the cost of applying the IDLC function to the local exchange is not high, the cost of replacing all of the DLC type FLC devices configured in the existing network with the new FLC device having the IDLC function is too high.

Accordingly, an object of the present invention is to remove the digital subscriber matching device from the central station terminal (COT) in consideration of the above points, and instead of using the V5.x protocol conversion method, without the addition or modification to the remote subscriber side of the IDLC method as it is. The present invention provides a V5 protocol converter capable of acquiring subscribers integrated by IDLC in a local exchange and an ISDN network access method using the same.

1 is a block diagram showing a digital network access device by a general DLC method,

2 is a block diagram illustrating a digital network access device using an IDLC method to which a V5 protocol converter according to the present invention is applied;

3 is a flowchart illustrating a method of converting a DLC signal to an IDLC protocol in the V5.x protocol converter of FIG. 2;

4 is a flowchart illustrating a method of converting an IDLC protocol into a DLC signal in the V5.x protocol converter of FIG.

<Description of the symbols for the main parts of the drawings>

10,50: Local exchange 20,70: Central station terminal (COT)

30: remote terminal (RT) 40: ISDN BRI subscriber terminal

60: V5.x protocol converter 75A, 75B: E1 relay line

The V5 protocol converter of the present invention for achieving the above object, in the apparatus for digital network access in the local exchange period of the DLC remote subscriber station and IDLC method, E1 between the local exchange and the remote subscriber station; It is connected via a relay line, characterized in that the means for converting the DLC signal transmitted from the subscriber station into a protocol suitable for the local exchange, and converts the IDLC signal transmitted from the local exchange into a protocol suitable for the subscriber terminal.

The ISDN network access method using a V5 protocol converter for achieving the object of the present invention, in the method for the digital network access in the local exchange period of the DLC remote subscriber station and IDLC method, (1) the remote subscriber station And (2) converting the DLC signal of the subscriber station into a protocol that is accepted by the IDLC scheme and transmitting it to the local exchange, and (3) the local exchange between the local exchange and the local exchange. And converting the IDLC signal of the exchange into a protocol that is accepted by the DLC scheme and transmitting it to the subscriber station.

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

The present invention is a matching method between an IDLC local exchange and an existing ISDN BRI subscriber terminal of DLC, wherein ISDN subscriber channel capacity and V5.x (V5.1 and V5.2) are transmitted / received through D1 channel of E1 relay line. Depending on the aggregation rate of the local exchange that accommodates the protocol, up to 21 E1 (up to 10 ISDN subscriber line matching) -210 ISDN BRI subscribers can be accessed and the DLC signal is integrated into the protocol of IDLC V5.1 or V5.2. As a message, an IDLC V5.x protocol message is converted into a DLC signal, and an IDLC type local exchange and a DLC type ISDN subscriber channel are presented. The V5.x protocol serves as the Digital Trunk Protocol Converter and the Cross Connect System for future use in the transmission field.

2 is a block diagram of a digital network access device using an IDLC method to which a V5 protocol converter according to the present invention is applied. The apparatus shown in FIG. 2 is configured in the same manner as the conventional apparatus of FIG. 1, and instead of removing the digital subscriber matching apparatus from the central station terminal (COT) 70 on the remote subscriber side, the apparatus of the present invention is exchanged with the local exchange 50. It is configured to further include a V5.x protocol converter 60. The V5.x protocol converter 60 receives the E1 relay line matching device 61A, 61B for matching between the central office terminal (COT) 70 and the local exchange 50 via the E1 relay lines 75A, 75B. D + channel extraction / insertion device 62 for extracting D + channel from DLC signal and dividing it into D channel and port control signal or inserting D channel and port control signal into D + channel of the corresponding port, and dual for storing port control signal. A port RAM (DPRAM) 63 is provided. The V5.x protocol converter 60 also checks the state transition of the port control signal read by accessing the dual port RAM (DPRAM) 63 or the ISDN subscriber port according to the current port state for the input port control message. The protocol conversion module 64 converts the control message and stores it in the dual port RAM (DPRAM) 63. When a transition occurs for each channel, the V5.x protocol is converted or inputted into a V5.x protocol message according to the current port state. A V5.x protocol processing module 68 for analyzing the message and outputting necessary data to the protocol conversion module 64, and the E1 relay line matching device 61B using the separated D-channel data and the V5.x protocol message as IDLC signals. The V5.x / D protocol processing apparatus 69 for transmitting the V5.x protocol message and the D channel data from the IDLC signal received from the local exchange 50 through the relay line channel linked through the Equipped. On the other hand, the V5.x protocol converter 60 performs time switch 67 and switch processing for implementing the aggregation function of the IDLC between the D + channel extraction / insertion device 62 and the V5.x / D protocol processing device 69. Module 66, and a system controller 65 for controlling the overall operation of each component. The operation of the digital network access device by the IDLC method to which the V5 protocol converter of FIG. 2 having such a configuration is applied will be described in detail with reference to FIGS. 3 and 4.

First, a method of converting a DLC signal transmitted from a remote subscriber side into an IDLC signal suitable for the IDLC local exchange 50 of the network service provider side will be described with reference to FIG. 3. The V5.x protocol converter 60 matches the E1 relay line matching device 71 of the central station terminal (COT) 70 on the remote subscriber side through the E1 relay line matching device 61A, and the remote terminal (RT) 30. Receives a DLC signal transmitted from the ISDN BRI subscriber station 40 through. The D + channel extraction / insertion device 62 of the V5.x protocol converter 60 extracts the D + channel for each port from the received DLC signal (step 301), and extracts the D channel signal and the port control signal from the extracted D + channel, respectively. To separate (step 302). Here, the two bits of the separated D-channel for each port are transferred directly to the V5.x / D protocol processing device 69 through the time switch 67 (step 309), and the one-bit port control received every two frames. The signal is collected and stored in the byte position of the corresponding order of the corresponding port of the dual port RAM (DPRAM) 63 when one byte is made (step 304). The dual port RAM (DPRAM) 63 stores one complete port control signal for a total of 12 ms. The D + channel extraction / insertion device 62 stores headers for every 6 bytes (48 bits) of port control signals and stores 0 and 1 alternately every 12 m. The protocol conversion module 64 accesses the dual port RAM (DPRAM) 63 every 12 ms to read out the stored port control signal (step 304), and arranges the read port control signals in order according to the head in order to double last. A state transition test is performed with a Double Last Look algorithm (step 305). The double last algorithm is considered to be a transition only if the converted signal is maintained for two times with respect to the changed signal. The protocol conversion module 64 checks the transition of the port control signal at a time to process up to 210 ISDN BRI subscriber ports at a time, and the synchronization may be different for each port, so the dual port RAM (DPRAM) 63 is accessed every 12 ms to check the transition. Do The protocol conversion module 64 determines the transition test result of the port control signal (step 306), and if the transition does not occur, controls to repeat the operation from step 305, and if the transition occurs, each port has a port state. A port control signal having a transition is defined according to the current port state, and a corresponding V5.x protocol message is transmitted to the V5.x protocol processing module 68 together with the port number (step 307). At this time, the protocol conversion module 64 changes the port state of the corresponding port to the next state according to the finite state machine (FSM). The V5.x protocol processing module 68 converts the V5.x protocol message, that is, the protocol that can be processed by the IDLC local exchange 50 based on the contents received through the system controller 65, to V5.x / The protocol is sent to the D protocol processing device 69 (step 308). The V5.x / D protocol processing unit 69 formats the V5.x protocol message received from the V5.x protocol processing module 68 and then defines a predefined data link channel through the E1 relay line matching device 61B. Is sent to the local exchange 50 (step 312). Meanwhile, the V5.x / D protocol processing apparatus 69 stores the D channel signal received from the D + channel extraction / insertion apparatus 62 through step 309 (step 310) and checks whether the data is valid data. (Step 311). If the check result of step 311 is not valid data, the V5.x / D protocol processing apparatus 69 repeats the steps from step 310. If the valid data is received, the V5.x / D protocol processing apparatus 69 sequentially stores the data as long as the valid length of the data. In step 312, the protocol message is formatted and transmitted to the predefined data link channel through the E1 relay line matching device 61B.

Through these steps, the DLC signal transmitted from the remote subscriber side is converted into an IDLC signal and transmitted to the IDLC local exchange 50. On the contrary, when converting the IDLC signal transmitted from the local exchange 50 of the network service provider side into a DLC signal suitable for the DLC terminal of the remote subscriber side, the reverse steps of the above steps may be performed. This will be described with reference to FIG. 4.

In Fig. 4, the V5.x protocol converter 60 receives the IDLC message from the local exchange 50 over the data link channel of the E1 relay line matching device 61B. The V5.x / D protocol processing apparatus 69 analyzes the message format of the received IDLC signal (step 401), and separates the port control signal from the ISDN LAPD, that is, the D channel signal (step 402). Two bits of the separated D-channels for each port are stored once (step 408), and in turn are switched to the D + channel extraction / insertion device 62 through the time switch 67 (step 409). On the other hand, the separated port control signal is collected in a predetermined internal format to send an interrupt signal (interrupt signal) to the V5.x protocol processing module 68, when the interrupt signal is detected in the V5.x protocol processing module 68, V5. The data is read from the x / D protocol processing device 69, analyzed, and transmitted to the protocol conversion module 64 with the port number through the system control device 65 in the case of the subscriber port control message (step 403). The protocol conversion module 64 analyzes the received message according to the FSM, and converts the received message into a corresponding port control signal according to the current port state of the corresponding port (step 404). The converted port control signal is stored in sequence at the position of the corresponding port of the dual port RAM (DPRAM) 63 (step 405). At this time, the protocol conversion module 64 converts the port state of the corresponding port to the next state according to the FSM. The D + channel extraction / insertion device 62 accesses the dual port RAM (DPRAM) 63 to read the stored port control signal (step 406), and alternately inserts the read port control signal and the dummy signal into the D + channel. (Step 407). Whenever the port control signal is inserted into the D + channel, the dual port RAM (DPRAM) 63 is read in the byte unit and inserted in sequence, so that the protocol conversion module 64 changes the dual port RAM (DPRAM) 63. The port control signal is naturally transmitted to the remote subscriber station continuously through the D + channel of the 3DS0 E1 relay line until the next change (step 410). On the other hand, ISDN LAPD data that is switched and received from the V5.x / D protocol processing device 69, that is, D channel data, is automatically inserted into the corresponding bit position of the D + channel of the corresponding port in the E1 relay line as received by 2 bits automatically. Step 410 is transmitted to the remote subscriber station.

Through these steps, the IDLC signal transmitted from the local exchange is converted into a DLC signal and transmitted to the DLC remote subscriber station.

On the other hand, the B channel to the exchange is not fixed to the remote subscriber port, but the time switch 67 of FIG. The switch processing module 66 configures all databases and algorithms so as to be switched with the channel of the E1 relay line corresponding to the generated remote subscriber port to realize the B channel integration function.

As described above, the V5 protocol converter of the present invention and the ISDN network access method using the same, when the IDLC method is applied to the local exchange that has accommodated the remote subscriber in the DLC method, uses the V5.x protocol converter to switch and the DLC method remote subscriber. By eliminating subscriber matching devices from the terminal and accommodating remote subscribers using the integrated IDLC method without any additional changes, it is possible to drastically reduce the device cost and maintenance cost, and to cope with the improvement of flexible subscriber service quality by utilizing the aggregation rate. It works.

Claims (9)

An apparatus for accessing a digital network in a local exchange period of an IDLC scheme with remote subscriber stations of a DLC scheme, It is connected between the local exchange and the remote subscriber station via an E1 relay line, converts the DLC signal transmitted from the subscriber station into a protocol suitable for the local exchange, and converts the IDLC signal transmitted from the local exchange into a protocol suitable for the subscriber station. A V5 protocol converter comprising means. The method of claim 1, wherein the V5 protocol converter is A plurality of E1 relay line matching devices for matching between the remote subscriber stations and the local switch via an E1 relay line, respectively; The D + channel is extracted from the DLC signal received from the remote subscriber station matched to the E1 relay line matching device, separated into a D channel and a port control signal, and the port control signal read and accessed from the D channel and the dual port RAM is input. A D + channel extraction / insertion device inserted into the D + channel of the port and transmitted to a remote subscriber station matched to the E1 relay line matching device; A dual port RAM configured to store a port control signal separated from the D + channel extraction / insertion device or a port control signal converted from a protocol conversion module; A protocol conversion module for inspecting a state transition of the port control signal read by accessing the dual port RAM or converting the port control message into an ISDN subscriber port control message according to the current port state and storing the port control message in the dual port RAM; A V5.x protocol processing module for converting into V5.x protocol messages or analyzing input V5.x protocol messages according to the current port state when a transition occurs for each channel and outputting necessary data to the protocol conversion module; And The separated D-channel data and V5.x protocol message are transmitted as the IDLC signal to the trunk line channel linked through the E1 relay line matching device to the local exchange or from the IDLC signal received from the local exchange to the V5.x protocol message and D-channel data. A V5 protocol converter, characterized in that consisting of a V5.x / D protocol processing unit for separating. 3. The V5 protocol converter is connected between the D + channel extraction / insertion device and the V5.x / D protocol processing device to match up to 10 ISDN subscriber lines per E1 according to the aggregation rate of the local exchange. V5 protocol converter further comprising a switch for. 3. The apparatus of claim 2, wherein the D + channel extraction / separation apparatus separates the 2-bit D-channel signal and the 1-bit port control signal for each port from the D + channel extracted from the received DLC signal, and separates the separated D-channel signal. A V5 protocol converter for switching to a V5.x / D protocol processing device and storing the separated port control signals in order in the corresponding port position of the dual port RAM. The protocol conversion module of claim 2, wherein the protocol conversion module accesses the dual port RAM at a predetermined time period and checks a state transition using a double look algorithm, and receives the input from the V5.x protocol processing module. The V5 protocol converter converting data into a port control message and storing the data in a dual port RAM for access by the D + channel extraction / insertion device. 5. The apparatus of claim 4, wherein the V5.x / D protocol processing apparatus temporarily stores the D channel signal obtained by analyzing the received IDLC signal, and then switches to the D + channel extraction / insertion apparatus by 2 bits in order. V5 protocol converter. In the method for the digital network access in the local exchange period of the DLLC remote subscriber terminal and IDLC method, (1) matching between the remote subscriber stations and the local exchange via an E1 relay line; (2) converting the DLC signal of the subscriber station into a protocol accommodated by IDLC and transmitting it to the local exchange; And (3) converting the IDLC signal of the local exchange into a protocol accommodated by the DLC scheme and transmitting the converted protocol to the subscriber station. 8. The method of claim 7, wherein the step (2) (2a) Receive a DLC signal consisting of 2B + D + channels each containing two B-channels, one D-channel, and one unused bit of the D-channel and a port control signal, and for each port in the received DLC signal. Extracting a D + channel; (2b) separating the D channel signal and the port control signal from the extracted D + channel; (2c) checking the state transition of the separated port control signal and converting it into an IDLC protocol message when the transition occurs; And (2d) transmitting the separated D-channel signal and the converted IDLC protocol message to the local exchange through the predefined data link channel, respectively. 8. The method of claim 7, wherein the step (3) (3a) separating the D channel signal and the port control signal by analyzing the message format of the received IDLC signal; (3b) checking the state transition of the separated port control signal and converting it into an ISDN subscriber protocol message accordingly; And And (3c) inserting the separated D channel signal and the converted ISDN subscriber protocol message into the D + channel of the corresponding port, and transmitting the same to the subscriber station.