KR100233944B1 - Atm multiplexer using vpi - Google Patents

Abstract

The present invention relates to an Asynchronous Multiplexing Mode (ATM) multiplexing apparatus using a virtual path identifier (VPI), wherein an ATM cell received in various line connection methods (STM1, 25M, DS3, etc.) such as an ATM switch or other transmission equipment is ATM. A device that multiplexes multiple subscribers with various transmission rates (DS3 level signal, DS1E level signal, and 25M level signal) using VPI of a cell, and can accommodate various physical layer access methods of various services and broadcast them. Since cell copy function is simultaneously performed on all subscriber ports, it minimizes cell transmission delay and also has the advantage of minimizing cell delay of a specific port because multiple cells are multiplexed in a round robin manner.

Description

Asynchronous Transmission Mode (ATM) Multiplexing Device Using Virtual Path Identifier (VPI)

The present invention relates to an asynchronous transmission mode (ATM) multiplexing apparatus using a virtual path identifier (hereinafter referred to as VPI), and to various line connection methods (STM1, 25M, DS3, etc.) such as an ATM switch or other transmission equipment. The present invention relates to an apparatus for multiplexing ATM cells received by multiple subscribers at various transmission rates (DS3 level signal, DS1E level signal, 25M level signal).

Hyundai is a high-speed era, an information age.

In these times, the speed of communication equipment is improving day by day, and there are many things that are used as necessities in real life.

However, the higher the speed, the higher the cost.

That is, parts are becoming expensive due to ultra-light weight, thinness and miniaturization of equipment, and communication equipment manufactured using such parts also becomes expensive.

For example, a switch for transmitting a cell transmitted in a network to a plurality of subscribers, a cable connecting between subscriber terminals connected thereto, and equipment used therebetween.

In such a communication system, an optical transmission line is suitable to send information to subscriber stations at high speed.

However, such an optical transmission line is very expensive, so installing an optical line per subscriber is very uneconomical.

And since the transmission bands of subscriber stations are DS1E or 25M, there is no need to install expensive optical transmission lines for each subscriber.

In view of the above-described conventional matters, an object of the present invention is to provide a multiplexing device capable of providing an economical and high speed transmission equipment.

That is, since one high-speed network connection line, in particular an optical transmission line, can transmit high-speed ATM cells, one high-speed transmission line from a switch and other transmission equipment is connected to the multiplexing apparatus of the present invention located at a remote location. By accessing multiple low- and medium-speed subscriber terminals in a short distance, it is possible to reduce expensive transmission line line costs and to easily configure a subscriber-side access network.

1 is a diagram showing a correlation between network ATM cell VPI and subscriber port-specific ATM cell VPI.

2 is a block diagram of the multiplexing apparatus according to the present invention.

3 is a detailed block diagram of a multiplexer of a second building.

4 is a detailed block diagram of a subscriber connection of FIG.

<Explanation of symbols for main parts of drawing>

100: multiplexing device 10: network connection

20: multiplexer 21: reception conversion table

22, 22-1, 22-2, 22-3: Pipo 23: Receive VPI conversion unit

24: network side OAM cell filter 25: transmission conversion table

26: transmitting VPI converter 27: subscriber-side OAM cell filter

30: subscriber connection 31, 33, 34, 36: Pipo

32: ATM cell filtration device 35: multiplexer

37: port control unit 38: physical layer connection unit

The configuration of the multiplexing apparatus of the present invention to operate as described above comprises: a network connection unit connected to a network side and transmitting / receiving an ATM cell; A multiplexing unit for converting a virtual path identifier (VPI) of an ATM cell input through the network connection unit and generating and removing a link header including a subscriber board identifier and a subscriber port identifier; After performing the cell filtration function according to the link header of the ATM cell transmitted from the multiplexer, the link header is removed and transmitted to each physical port, and conversely, the link header is generated to the multiplexed ATM cell transmitted from the subscriber board. Subscriber connection for transmitting to the negative; And a system control unit which controls the entire unit, processes OAM functions by transmitting and receiving network side OAM cells and subscriber side OAM cells, and performs initialization and operation control management functions, and accesses various physical layers of various services. It is characterized by accepting the method.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram illustrating a correlation between network ATM cell VPI and subscriber port ATM cell VPI. In the multiplexing apparatus implemented according to the present invention, the number of available VPIs for a subscriber station is limited depending on the number of subscriber ports. As a function, the subscriber station can use any VPI value. Since the VCI value is transmitted to the subscriber station with the same value as the network access ATM cell, the VCI value maintains transparency between the network side and the subscriber.

The side connected to the network side in the multiplexing apparatus 100 has several VP groups so as to accommodate various transmission bands transmitted from an exchange and other transmission equipment using an STM-1 class optical line. Multiplex the information inputted through the multiple ports (VP0 ~ VPm ~ VPZ) and transmit them to cable ports such as DS1E (VP0, VP1 ~) or 25M class and transmit them to multiple subscriber terminals connected to this port.

2 is a block diagram of a multiplexing apparatus according to the present invention, which is connected to an STM-1 (or DS3, 25M) network (switch or other transmission device) and transmits / receives an ATM cell; A multiplexer 20 for performing VPI conversion of an ATM cell input through the network connection unit 10 and generating and removing a link header including a subscriber board identifier and a subscriber port identifier; After performing the cell filtering function according to the link header of the ATM cell transmitted from the multiplexer 20, the link header is removed and transmitted to each physical port, and conversely, the link header is transmitted to the ATM cell transmitted from the subscriber board. A subscriber access unit 30 generating and transmitting to the multiplexer 20; And a system control unit 40 for controlling the entire unit, processing the OAM function by transmitting and receiving network side OAM cells and subscriber side OAM cells, and performing initialization and operation control management functions through an operator-connected RS232C line. do.

In this case, when the ATM cell having a link header is input in addition to the function, the multiplexer 20 simultaneously transmits the cell to all the subscriber boards connected to the subscriber access unit 30, and the ATM cell transmitted from each subscriber board side. Minimizes cell delay on a specific port by performing multiplexing function in a round robin manner per cell, and simultaneously performing cell copy function on all ports to be broadcasted when processing broadcast function do.

In this way, ATM cell broadcast is performed by transmitting ATM cell to all subscriber boards simultaneously.

In addition, the subscriber access unit 30 transmits all ports after performing a primary multiplexing function in a round robin manner before transmitting the ATM cell transmitted from the subscriber board to the multiplexer 20.

The multiplexing apparatus schematically configured as described above receives a plurality of STM-1 or DS3, 25M signals transmitted from an ATM exchanger and other transmission equipment through the network connection unit 10 and is connected to the subscriber connection unit 30. Subscriber board side of DS3 (approximately 45Mbps) signal, DS1E (2.0438Mbps) signal and 25M signal are multiplexed and transmitted.

3 is a detailed block diagram of the multiplexer 20 performing the above functions, and includes a reception conversion table 21 storing link header information according to a VPI value of one network side cell; A first pipo 22 for storing an OAM cell to be transmitted to a subscriber side transmitted from the system controller 40; The OAM cell stored in the PIPO 22 and the cell transmitted from the network side are multiplexed, and then converted into a VPI for transmission to the subscriber access unit 30 using the information stored in the reception conversion table 21, and then a link header. A reception VPI conversion unit 23 for generating an ATM cell having an MN; The network side OAM cell filter 24 extracts the OAM ATM cell transmitted from the network side among the ATM cells transmitted from the receiving VPI converter 23 and then transmits the remaining ATM cells excluding the cell to all subscriber access units 30. )Wow; A second pie 22-1 storing the network side OAM cell extracted from the network side OAM cell filter 24; A transmission conversion table 25 storing a link header transmitted from the subscriber access unit 30 and a network-side VPI value according to the VPI value of the subscriber access unit 30; A third PIPO 22-2 for storing an OAM cell for transmission from the system control unit 40 to the network side; After the cell stored in the PIPO 22-2 and the ATM cell transmitted from the subscriber access unit 30 are accessed in a round robin manner with the same priority, the information stored in the transmission conversion table 25 is used. A network-side transmit VPI converter 26 for converting to a network-side VPI; The subscriber-side OAM cell which extracts the OAM cell transmitted from the subscriber access unit 30 among the ATM cells transmitted by the transmitting VPI converter 26 and then transmits the remaining ATM cells excluding the cell to the network access unit 10. Filter 27; And a fourth PIPO 22-3 storing the subscriber side OAM cell extracted from the subscriber side OAM cell filter 27.

The reception conversion table and the transmission conversion table are configured as bidirectional port memories for simultaneous access by the respective VPI conversion units 23 and 26 and the system control unit 40.

4 is a detailed block diagram of the subscriber access unit 30. After filtering only the cells to be transmitted to the corresponding subscriber board among the ATM cells having the link header received from the multiplexer 20 through the first PIPO 31, An ATM cell filtration device 32 for transmitting cells for each of the subscriber ports 1 to M through the second PIPO 33; M (M: access of one subscriber board) for multiplexing the ATM cells transmitted from the subscriber port through the third PIPO 34 to the multiplexer 20 through the fourth PIPO 36 by multiplexing in a round robin manner. Number of ports) x 1 multiplexer 35: a port controller 37 for performing a physical cell connection matching function between the ATM cell filtration device 32 and the multiplexer 35 and the subscriber board; And a physical layer connection unit 38 that handles connection functions for physical subscriber port connections of DS1E, DS3, and 25M.

The port controller 37 generates an ATM cell having a link header composed of a port identifier and a subscriber board identifier in an ATM cell transmitted from a subscriber port for a matching function, and transmits the multiplexer (3) through the third PIPO 36. 32). At this time, the transmitting ATM cell performs a function of controlling that no overflow occurs on the pipe 36.

The operation of the multiplexing apparatus of the present invention configured as described above will be described as follows when the ATM cell generated at the network side is transmitted to the subscriber station and the cell generated at the subscriber terminal is transmitted to the network side.

First, a process of transmitting from the network side to the subscriber station is described. When an ATM cell is input through the network connection unit 10, the network-side receiving VPI converter 23 attempts to transfer the subscriber cell stored in the first pipe 22. The OAM cell and the cell transmitted from the network side are multiplexed, and then converted into VPI for transmission to the subscriber access unit 30 using the information stored in the reception conversion table 21 to generate an ATM cell including a link header.

Subsequently, the generated ATM cell is input to the network-side OAM cell filter 23 to extract only the OAM ATM cell transmitted from the network side among the ATM cells, and then to the second control unit 40 to be transmitted to the system control unit 40. In addition, the remaining ATM cells except for network side OAM cells are transmitted to all subscriber access units 30.

The cell is input to the first pipe 31 in the subscriber access unit 30, and then through only the ATM cell including the link header through the ATM cell filter unit 32, the cell to be transmitted to the corresponding subscriber board passes through the port control unit 37. ) Is entered.

The port control unit 37 performs a cell connection matching function for transmitting the cell transmitted from the physical layer connection unit 38, and the cell is matched for physical subscriber port access of DS1E or 25M level. It is input to the physical layer connection unit 38 and finally transmitted to the subscriber board (not shown).

Meanwhile, a process of transmitting the cell transmitted from the subscriber station to the network side is as follows.

When the subscriber cell is input through the physical layer connection 38 of the subscriber access unit 30, the cell is generated as an ATM cell having a link header in the port control unit 37, which is an ATM cell transmitted from the subscriber port. This cell contains a port identifier and a subscriber board identifier.

As described above, the port control unit 37 that generates the ATM cell transmits the cell to the multiplexer 35 through the third pipes 34, and the transmitted ATM cell generates an overflow in the pipes 34. Control not to.

Subsequently, the multiplexer 35 receiving the cell is multiplexed with the cells and transmitted to the multiplexer 20, and the multiplexer 20 transmits the OAM to the network side stored in the third PIPO 22-2. After the cell and the ATM cell transmitted from the subscriber access unit 30 are restrained by a round robin method having the same priority, the cell is converted into a network-side VPI using the VPI values stored in the transmission conversion table 21. .

The converted information is then transmitted to the fourth PIPO 22-3 after filtering only the OAM cells transmitted from the subscriber access unit 30 through the subscriber-side OAM cell filter 26, and the other subscriber access unit 30. The ATM cell and the network side OAM cell transmitted in FIG. 2) are transmitted to the network side connection unit 10, which is then input to an exchange and other transmission equipment connected to the multiplexing apparatus 100 of the present invention.

Through the above transmission / reception process, signals of various transmission bands between the network side and the subscriber board side are transmitted through one multiplexing device.

For reference, a subscriber board identifier and a subscriber board port identifier value according to the VPI values of the network side and the subscriber side used in the present invention are described as an example, and the values are shown in the following table. A variable value that can be changed by the control unit is controlled by the system control unit 40.

As described in detail above, in the present invention, when multiplexing devices used between the network side and the subscriber board are implemented, multiplexing using the VPI of an ATM cell can accommodate various physical layer access methods of various services and broadcast all subscribers. Since the cell copy function is simultaneously performed on the port, the cell transmission delay is minimized. Also, since the cells are multiplexed in a round robin manner, the cell delay of a specific port is minimized.

In addition, a preferred embodiment of the present invention is disclosed for the purpose of illustration, those skilled in the art will be able to make various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the following claims You will have to look.

Claims (9)

A network connection unit connected to the network side to transmit / receive ATM cells; A multiplexing unit for converting a virtual path identifier (VPI) of an ATM cell input through the network connection unit and generating and removing a link header including a subscriber board identifier and a subscriber port identifier; After performing the cell filtering function according to the link header of the ATM cell transmitted from the multiplexer, the link header is removed and transmitted to each physical port, and conversely, the link header is generated to the multiplexed ATM cell by the subscriber board. Subscriber connection for transmitting to the negative; And a system controller for controlling the entire unit, transmitting and receiving network side OAM cells and subscriber side OAM cells, processing OAM functions, and performing initialization and operation control management functions, and accessing various physical layers of various services. ATM multiplexing device using a VPI, characterized in that to accommodate the scheme. The system of claim 1, wherein the multiplexer comprises: a reception conversion table storing link header information according to a VPI value of a network ATM cell; Speed matching first storage means for storing an OAM cell to be transmitted to the subscriber side transmitted from the system controller; After multiplexing the OAM cell stored in the first storage means and the cell transmitted from the network side, and converts it into a VPI for transmission to the subscriber access unit by using the information stored in the reception conversion table, and generates an ATM cell having a link header A receiving VPI converter; A network-side OAM cell filter for extracting an OAM ATM cell transmitted from the network side among the ATM cells transmitted from the receiving VPI converter and then transmitting the remaining ATM cells excluding the cell to all subscriber access units; Speed matching second storage means for storing the network side OAM cell extracted from the network side OAM cell filter; A transmission conversion table storing a link header transmitted from the subscriber access unit and a network side VPI value according to the VPI value of the subscriber access unit; Speed matching third storage means for storing an OAM cell for transmission from the system controller to the network side; A network-side transmit VPI converter for multiplexing the cell stored in the third storage means and the ATM cell transmitted from the subscriber access unit and then converting the information stored in the transmit conversion table into a network-side VPI; A subscriber-side OAM cell filter which extracts the OAM cell transmitted from the subscriber access unit among the ATM cells transmitted by the transmitting VPI converter and then transmits the remaining ATM cells excluding the cell to the network access unit; And a fourth storage means for speed matching storing the subscriber-side OAM cell extracted by the subscriber-side OAM cell filter. The ATM multiplexing device of claim 2, wherein the reception conversion table and the transmission conversion table are configured as bidirectional port memories to be simultaneously accessed by each reception / transmission VP I conversion unit and a system control unit. The ATM multiplexing apparatus of claim 2, wherein the transmitting VPI converter multiplexes the OAM cell and the ATM cell in a round robin manner having the same priority. The ATM using the VPI of claim 1 or 2, wherein the multiplexer processes a broadcast function to minimize cell delay of a specific port by simultaneously performing a cell copy function on all ports to be broadcast. Multiplexing device. The method of claim 1, wherein the subscriber access unit ATM cell filtration device for filtering only the cells to be transmitted to the corresponding subscriber board of the ATM cells having a link header received from the multiplexer, and transmits the cells for each subscriber port; A multiplexer for multiplexing the ATM cells transmitted from the subscriber port to the multiplexer; A port controller for performing a physical cell connection matching function between the ATM cell filtration device and the multiplexer and a subscriber board; And a physical layer connection unit for processing an access function for physical subscriber port access of various transmission bands. The apparatus of claim 6, wherein the multiplexer multiplexes a cell at a subscriber side by adopting a round robin multiplexing scheme. The method of claim 6, wherein the port control unit for the matching function, the ATM cell having a link header consisting of a port identifier and a subscriber board identifier in the ATM cell transmitted from the subscriber port to transmit to the multiplexer through a third storage means And at the same time, the transmitting ATM cell performs a function of controlling an overflow from occurring on the storage means. The ATM multiplexing apparatus of claim 1, wherein the system control unit variably modifies the reception conversion table, the VPI stored in the transmission conversion table, and corresponding information according to a system environment and a user.

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