KR100260900B1 - Segmentation apparatus and method in atm communication system - Google Patents

Abstract

PURPOSE: A segmentation apparatus in an ATM communication system and a method thereof is provided to carry out transmission processing for cell data without using a cell buffer. CONSTITUTION: An ATM communication system provided with a segmentation apparatus consists of a host(100), a physical layer processing unit(130), a local memory(120), and an ATM processing unit(200). The ATM processing unit(200) is comprised of a host interface part(201), an LM(Link Management block)(203), a PM(Processor Management block)(204), and a CS(Convergence Sublayer)-ATM(205). The host interface part(201) executes interface processing to transmit and receive with the host(100). The LM(203) executes link processing for a generated descriptor. The PM(204) transmits the transmission request, header, CRC, address and length information of the cell data to be transmitted to the CS-ATM(205). The CS-ATM(205) requests the host interface part(201) to transmit a cell, referring to the cell transmission request signal transmitted from the PM(204) and Txclav transmitted to the physical layer processing unit(130). The CS-ATM(205) transmits the address and length information of the packet data to be transmitted to the host interface part(201). The CS-ATM(205) forms an ATM cell for the packet data transmitted from the host interface part(201) and transmits the formed ATM cell to the physical layer processing unit(130).

Description

Segmentation Apparatus and Method in Asynchronous Transmission Mode Communication System

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a segmentation apparatus and method in an asynchronous transfer mode (hereinafter, referred to as ATM) communication system. In particular, the present invention is implemented to transmit cell data without a cell buffer. Segmentation apparatus and method.

In general, in the ATM communication system, segmentation is a function of dividing cell data transmitted from a host through an ATM adaptation layer (hereinafter referred to as AAL) processing and an ATM layer process to transmit the data to the physical layer. It is configured and operated as shown in FIG.

First, a descriptor table is formed in a predetermined unit every time cell data is generated in the host 100, and a virtual corresponding to each time a mutual channel is formed between the host and the ATM processor 110. A channel (Virtual Channel) table is formed. In this way, the link management unit (hereinafter, referred to as LM) 113 with reference to the descriptor table and the virtual channel table formed in the local memory 120 performs link processing on the newly generated descriptor. When the linking operation is performed to some extent, the control unit 112 controls the process management unit (hereinafter, referred to as PM) 114 to be driven.

Accordingly, the PM 114 reads the address and length information of the cell to be transmitted by referring to the descriptor table stored in the local memory 120 and transmits it to the host 100 through the host interface 111. At the same time, the cell transmission request signal is sent to the host interface unit 111. The PM 114 transmits the header, CRC, and length information of the cell to be transmitted to the convergence sublayer and the ATM layer processor (hereinafter, referred to as CS-ATM) 116. The host 100 reads out the corresponding cell data (packet data) stored in the local memory 120 using the applied address and length information and transmits the cell data (packet data) to the host interface 111.

The host interface 111 transmits and stores the received cell data to the cell buffer 115. The cell buffer 115 stores the cell transmitted from the host interface 111 until the read control signal Read is transmitted from the CS-ATM 116. Therefore, the cell buffer must be configured to store one or more cell data.

If the transmission time of the physical layer processing means 130 is correct, the CS-ATM 116 transmits a read control signal to the cell buffer 115 to read 48 bytes, and the PM 114 reads the 48-byte cell data. A trailer and a header using the provided CRC and length information are inserted to form an ATM cell and transmitted to the physical layer processing means 130.

As such, in order to transmit a cell transmitted from a host to a physical layer processor, a cell buffer having a capacity to store at least one cell or more must be provided, and a local buffer is transmitted while the PM transfers cell data transmitted from the host to a buffer. Because it occupies memory, the LM could not link to the newly generated descriptor table and thus could not efficiently operate the ATM processing time.

An object of the present invention is to provide a segmentation apparatus and method capable of transmitting a cell data without using a cell buffer in an asynchronous transmission mode communication system in order to simplify hardware and efficiently operate an ATM processing time. There is this.

In order to achieve the above object, the segmentation apparatus according to the present invention is asynchronous transmission of cell data transmitted from a host with reference to a descriptor table and a virtual channel table, which are connected to a physical layer processing means through a utopia interface and stored in a local memory. A segmentation apparatus of an asynchronous transmission mode communication system configured to transmit and configure in the form of a mode cell, the segmentation apparatus comprising: a host interface unit for performing an interface process to enable data transmission and reception between a host and a segmentation apparatus; A link management unit (LM) for link processing each time a new descriptor table is generated; when a cell transmission request signal is applied, address and length information of packet data for forming an asynchronous transmission mode cell is sent to the host interface unit, and the host unit is executed. Convergence sublayer and asynchronous transfer mode layer processor (CS-ATM) for forming an asynchronous transfer mode (ATM) cell of cell data transmitted through the physical layer processing means; and a descriptor table linked by the link manager and the corresponding virtual table. When a single asynchronous transmission mode cell is transmitted with reference to the channel table, the sublayer converges the cell transmission request signal, the corresponding header, error correction information (CRC), and address and length information of packet data read from the local memory. And a process management unit (PM) for outputting to the asynchronous transfer mode layer processing unit. The.

In order to achieve the above object, the segmentation method according to the present invention transmits and receives physical layer processing steps and ATM cell data using a utopia interface method, and transmits from a host with reference to a descriptor table and a virtual channel table stored in a local memory. In the segmentation method of the asynchronous transmission mode communication system for configuring and transmitting the cell data in the form of an asynchronous transmission mode cell, Link management step for the newly generated descriptor table; Descriptor table information can transmit a single asynchronous transmission mode cell A process management step of generating a cell transmission request signal and simultaneously generating a corresponding header, error correction information, and address and length information of a packet data to be sent; an address of a packet data generated in a process management step And A first transmission step of transmitting this information to the host and setting the standby state for transmitting the information to the host, and transmitting the address and length information of the packet data to the host when the cell transmission status availability command (Txclav) is activated in the physical layer processing step. When the packet data corresponding to the address and length information of the transmitted packet data are transmitted from the host, the physical layer of the asynchronous transmission mode cell formed by inserting the trailer information including headers, error correction information, and length information generated in the process management step And a second transmission step of transmitting to the processing step.

1 is a functional block diagram of an asynchronous transmission mode communication system having a conventional segmentation device,

2 is a functional block diagram of an asynchronous transmission mode communication system having a segmentation device according to the present invention;

3 is an operation flowchart for a segmentation method according to the present invention.

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

200: Asynchronous transfer mode (ATM) processing means 201: Host interface unit

202: control unit 203: link management unit (LM)

204: Process management unit (PM) 205: CS-ATM

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

2 is a functional block diagram of an asynchronous transmission mode communication system having a segmentation apparatus according to the present invention, the host 100, the physical layer processing means 130 and the local memory 120, which are configured in the same manner as in FIG. It consists of a newly implemented ATM processing means 200.

The ATM processing unit 200 includes a host interface unit 201 that performs interface processing so that data can be transmitted and received with the host 100, and a link management unit that performs link processing on the generated descriptor as shown in FIG. 1 (hereinafter, referred to as LM). 230, a process management unit (hereinafter referred to as PM) 204 for transmitting the transmission request, header, CRC, address, and length information for the cell data to be transmitted to the CS-ATM 205, which is transmitted from the PM 204 Transmitting the cell transmission request to the host interface 201 and the address and length information of packet data to be transmitted to the host interface unit 201 with reference to the Txclav transmitted to the cell transmission request signal and the physical layer processing means 130. The CS-ATM 205 is configured to form an ATM cell for the packet data transmitted from the host interface unit 201 and transmit the same to the physical layer processing means 130.

The segmentation device configured as described above is operated as follows.

First, a descriptor table is formed each time cell data is generated in the host 100 in the local memory 120, and a channel is formed whenever a channel between the host 100 and the ATM processing means 200 is formed. The virtual channel table is formed.

As described above, the LM 203 performs link processing on the descriptor table newly created in the local memory 120 by referring to the descriptor table and the virtual channel table formed in the local memory 120. The LM 203 reports to the control unit 202 whenever the link processing for one descriptor table is completed. The controller 202 controls the PM 204 to operate each time the link processing completion report is received from the LM 203.

Accordingly, the PM 204 checks whether a condition for transmitting a cell corresponding to the current 48 bytes is satisfied by referring to the descriptor stored in the local memory 120 and the corresponding virtual channel tables. As a result, when the current situation does not satisfy the condition for transmitting one cell, the controller 202 notifies this. Accordingly, the controller 202 again controls the LM 203 to perform a link operation on the newly generated descriptor, and controls the operation of the PM 204 as described above.

When the PM 204 determines that the condition for transmitting one cell is satisfied by the repetitive operation control between the LM 203 and the PM 204, the cell transmission request and the header, CRC, address and The length information is transmitted to the CS-ATM 205.

The CS-ATM 205 performs convergence sublayer processing and ATM layer processing performed in the existing AAL in transmitting ATM cells. When it is recognized that the cell transmission request signal is transmitted from the PM 204, the CS-ATM 205 performs a cell type configuration. Perform the relevant processing. First, the packet address and length information to be sent are sent to the host interface unit 201. In addition, the reception state of the Txclav command transmitted from the physical layer processing unit 130 interworked with the utopia interface method is checked. Txclav indicates whether the physical layer processing unit 130 is useful in the current cell transmission state, and means that the physical layer processing unit 130 may receive a cell from the ATM processing unit 200 when transmitted in the active state.

As a result of confirming the reception state, when the Txclav is in the active state, the CS-ATM 205 sends the cell data transmission request signal to the host interface unit 201. Accordingly, the host interface unit 201 transmits the address and length information of the packet data previously transmitted from the CS-ATM 205 to the host 100 to the host 100.

The host 100 reads the cell data having a corresponding length from the local memory 120 by referring to the address and length information of the received packet data as in the prior art, and sends it to the CS-ATM 205 through the host interface 201. send.

Accordingly, the CS-ATM 205 transmits the ATM cell formed by inserting the cell header and trailer previously transmitted from the PM 204 into the currently applied cell data to the physical layer processing means 130.

3 is an operation flowchart of a segmentation method according to the present invention, which is also an operation flowchart of each component shown in FIG.

As shown in FIG. 3,

When the link operation is performed to some extent in the LM 203, the corresponding process processing is performed in the PM 204 to transmit the cell transfer request and the header, CRC, address, and length information to the CS-ATM 205. In step 205, the packet address and length information corresponding to the host interface 201 are transmitted. At this time, the host interface unit 201 maintains the transmission standby state for the applied packet address and length information. If the CS-ATM 205 determines that the Txclav is in an active state and transmits a signal for requesting cell data transmission, the host interface 201 hosts the packet address and length information that maintained the standby state. Send to (100).

Accordingly, when the corresponding cell data is transmitted from the host 100, the cell 100 is directly transmitted to the CS-ATM 205 through the host interface 201 to form the corresponding ATM cell and transmitted to the physical layer processor 130.

As described above, the present invention has an advantage of simplifying hardware by configuring a segmentation apparatus of an ATM communication system so that an ATM cell can be transmitted without using a cell buffer. In addition, after transmitting the address and length information of the cell data to be transmitted to the CS-ATM, the PM does not participate in the transmission of the corresponding ATM cell so that the time that the PM occupies the local memory is shortened, so that the total ATM processing time It also shortens the effect.

Claims (3)

Asynchronous transmission mode communication system that is connected to the physical layer processing means by the utopia interface method and forms and transmits cell data transmitted from the host in the form of an asynchronous transmission mode cell by referring to the descriptor table and the virtual channel table stored in the local memory. Segmentation apparatus of A host interface unit for performing interface processing to enable data transmission and reception between the host and the segmentation device; A link management unit LM for link processing each time a new descriptor table is generated; When a cell transmission request signal is applied, address and length information of packet data for forming the asynchronous transmission mode cell is transmitted to the host interface unit, and an asynchronous transmission mode (ATM) cell of cell data transmitted through the host unit is formed. Convergence sublayer and asynchronous transmission mode layer processing unit (CS-ATM) for transmitting to the physical layer processing means; When it is time to transmit one asynchronous transmission mode cell with reference to the descriptor table linked by the link management unit and the corresponding virtual channel table, the cell transmission request signal, a corresponding header, error correction information (CRC), and the local And a process manager (PM) for outputting address and length information of the packet data read from a memory to the convergence sublayer and the asynchronous transfer mode layer processor. The method of claim 1, When the convergence sublayer and the asynchronous transmission mode layer processing unit receive a Txclav command from the physical layer processing unit in an active state, the convergence sublayer and the asynchronous transmission mode layer processing unit transmit a transmission request signal for the cell data to be sent to the host interface unit and transmit the address and And the length information is transmitted from the host interface unit to the host. Sends and receives physical layer processing steps and ATM cell data using the utopia interface method, and configures and transmits cell data transmitted from the host in the form of an asynchronous transmission mode cell by referring to a descriptor table and a virtual channel table stored in a local memory. In the segmentation method of an asynchronous transmission mode communication system, Link management step for the newly created descriptor table; When the descriptor table information is linked to transmit one asynchronous transmission mode cell, a cell transmission request signal is generated and corresponding header, error correction information, and address and length information of packet data to be transmitted are generated. Process management step; When the address and length information of the packet data generated in the process management step are set to a standby state for transmitting to the host, and the cell transmission state availability command (Txclav) is generated in the active state in the physical layer processing step, A first transmission step of transmitting address and length information of the packet data to the host; When the packet data corresponding to the transmitted packet data address and length information is transmitted from the host, the asynchronous transmission mode formed by inserting the trailer information including the header generated from the process management step, the error correction information, and the length information. And a second transmission step of transmitting a cell to the physical layer processing step.