KR980013146A - Multi-Frame Readout Method of Cell Decomposer in ATM Network - Google Patents

Abstract

The present invention relates to a method and apparatus for receiving data of a multi-frame by a cell decomposer that performs format conversion of data transmitted to an ATM cell in a matching apparatus for accommodating an existing PSTN subscriber of an ATM switching system under development as a network node of B- In a method of reading a buffer data of one frame, buffer data of a next frame to be served is read at the same time, and the number of times of reading the next buffer data To guarantee the stability for a larger number of channels, and to perform buffer data reading in multiple frames, thereby reducing the number of times of bus use and ensuring stability for a larger number of channels.

Description

Multi-Frame Readout Method of Cell Decomposer in ATM Network

FIG. 1 is a block diagram of a cell decomposer according to the present invention;

Figure 2 is a flow chart of a multi-frame readout of a cell decomposer in an ATM network of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

10: Cell decomposition buffer 20: ATM connection

30: Control memory 40: Time position connection

50: Time alignment unit

The present invention relates to a method of reading multiple frames of a cell decomposer in an ATM network and more particularly to a cell decomposer for an arbitrary bit rate service in an ATM network for accommodating existing PSTN subscribers of an ATM switching system under development as a network node of B- To a data frame reading method.

The time switch section should continuously transmit 1 octet data in one time slot time interval.

In order to perform this function, in the conventional method, the service configuration of the cell decomposition buffer of the corresponding frame is read by referring to the data configuration of the control memory for one time slot time for the channel to be served and the link, Or a method of reading the service data of the cell decomposition buffer of two consecutive channels and providing the data service to the time location unit.

However, the former method uses a longer control time due to frequent control memory and decomposition buffer read / write use.

Accordingly, there is a problem that the number of serviceable channels is limited due to the limitation of the bus use time, and a fast operation speed of the control memory is required.

Also, there is a problem that the latter method can be effectively used only in a limited case such as the case of a multi-channel service.

Accordingly, in order to solve the above problems, in the ATM network, the service data of the cell decomposition buffer in the cell decomposer for multiple frames of the same connection is read, some of the service data are transmitted to the time location unit, Thereby reducing the number of control memory and decomposition buffer readings to increase the number of serviceable channels, as well as greatly alleviating restrictions on the operation speed of the control memory.

According to an aspect of the present invention, there is provided a time-slot interface function of a cell decomposer for an arbitrary bit-rate service, the method comprising the steps of: Buffer data is simultaneously read to reduce the number of operations for reading the next buffer data, thereby ensuring stable operation of a larger number of channels.

In addition, buffer data reading is performed in multiple frames to reduce the number of times of bus use, thereby ensuring stable operation of a larger number of channels.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the embodiment of the present invention, a method of reading buffer data will be described in which the number of multiple frames is two frames.

FIG. 1 is a block diagram of a cell disassembler to which the present invention is applied.

A cell decomposition buffer 10 that uses a first-in first-out (FIFO) buffer for temporarily storing an input ATM cell, and an ATM cell read through the cell decomposition buffer 10 as a virtual path identifier / virtual A control memory 30 for storing an address, a control signal, and data output from the ATM connection unit 20, the ATM connection unit 20 dividing the ATM connection unit 20 by a channel identifier (VPI / VCI) A time position connection unit 40 for reading the ATM data stored in the control memory 30 in accordance with a time slot T / S by using a channel / link ID and an 8-bit counterpart data, And a timeslot matching unit 50 that uses a demultiplexer to convert the data into serial data and send it.

The overall operation of the present invention will now be described.

First, the cell decomposition buffer write operation will be described. The ATM cells received from the initial network are temporarily stored in the cell decomposition buffer 10.

The ATM connection unit 20 receiving the signal indicating that the cell is in the cell decomposition buffer 10 sends the buffer read signal to the cell decomposition buffer 10 to read the cell synchronizing signal and the ATM data.

At this time, if the cell synchronization signal is valid, VPI / VCI is extracted from the read data and the control data is read from the control memory 30.

Control data reading is performed twice, which is to perform multiple bit rate services.

The position to be recorded in the cell decomposition buffer is grasped through the control data, and the data received from the network is recorded at the position.

When the control data is updated again in the control memory 30 after the writing is completed, the operation of the ATM connection unit 20 ends.

Next, a cell decomposition buffer read operation according to the present invention will be described.

The time position matching unit 40 performs a cell disassembly function for reading and servicing data in the cell disassembly buffer 10 according to the data request of the time position interfacing unit 50. [

The controller 50 reads the control data of the control memory 30 with respect to the channel / link number received at the time location connection unit 50 and determines the position of the buffer in which data to be serviced is stored.

At this time, control data reading is performed twice for multiple bit rate services.

After the buffer is read, a write operation is performed to update the control data again.

Therefore, the bus is used for 3 read and 1 write operations.

This is the biggest limiting factor for density and channel count.

However, if the data after one frame (125 us) using the same control data is prepared as proposed in the present invention, it is sufficient to operate only one frame during two frame time, so that there is more margin for data bus use time, The element is resolved.

The time location connection unit 50 transmits a channel and a link number to be serviced to the time location matching unit 40, requests data, receives the requested data, and converts the serial data into serial data, .

The time position connection unit 50 receives the synchronous clock, generates a necessary state signal according to the operation, and sends the state signal to the ATM connection unit 20 and the time position matching unit 40.

FIG. 2 is a multi-frame readout flowchart of the cell decomposer of the present invention. FIG.

After reading and updating the control channel 30 of the even-numbered channel for the first even-numbered channel and the odd-numbered channel and the service request, the even-numbered channel data of the current frame and the next frame are read out from the cell decomposition buffer.

Only the current frame data 2n is serviced in the even channel time, and the next frame data 2n is stored for servicing in the next frame.

That is, only the sub channel for the even channel is used.

At this time, the same procedure as that before the start of reading is performed for the odd channel time.

And it works the same way to the last channel.

After the first frame, the next odd channel and even channel service procedure is repeated.

First, the even-numbered channel service process receives the service requests of the even-numbered channels 2n and odd-numbered channels from the time location access unit 40, which is a multiplexing unit (S1).

After the control memory is read and updated (S2) by the even channel 2n for the service request, the current frame, the next frame and the even channel data (ch2n, ch2n) are read from the cell decomposition buffer 10 (S3) .

Only the current frame data (2n) is serviced at the even channel time in the read even channel data and the next frame data (2n) is stored for servicing in the next frame (S4).

Then, it is determined whether the even-numbered channel data read from the cell decomposition buffer is read first (S5). If it is not the first reading, the odd-numbered channel data (2n + 1) .

Then, the above process is performed up to the last even-numbered channel (S7).

When the even channel service process is completed, the next odd channel service process is performed.

That is, in the odd channel service process, first, the even-numbered channel and the odd-numbered channel (2n + 1) service request are received from the time location access unit 40 (S8).

Upon receipt of the service request, data of the even-numbered channel (2n) previously stored in the even-numbered channel time is serviced (S9), and the control memory of the odd-numbered channel is read and updated (S10).

Then, odd channel data (ch2n + 1, ch2n + 1) of the current frame and the next frame are simultaneously read out from the cell decomposition buffer, and only the current frame data (2n + 1) 1) is stored for service in the next frame (S12).

That is, even-numbered channel data serves previously prepared data, and control memory read, write and cell decomposition buffer read occur only for odd frame data.

And then performs the odd channel service procedure by repeating the last channel S13.

Thus, the cell decomposition function can be performed in multiple frames.

As described above, the present invention reduces the number of control memory and decomposition buffer read operations in the cell disassembler by half, thereby increasing the limit of the number of serviceable channels and also greatly alleviating the restriction on the operation speed of the control memory.

Claims (3)

A method for reading multiple frames by a cell disassembler having a time location access unit, a cell decomposition buffer, and a control memory in an ATM switch, the method comprising the steps of: reading one frame of buffer data for an even channel service request received from the time position access unit An odd channel service step of simultaneously reading buffer data of a frame to be serviced, and an even channel service step of performing buffer data reading of one frame for an odd channel service request received from the time position accessing unit, And performing an odd channel service process for simultaneously reading buffer data of a frame to be serviced, wherein the buffer data reading is performed in multiple frames. 2. The method of claim 1, wherein the even channel service procedure further comprises: receiving a service request for an even channel and an odd channel from the time location access unit; Reading even channel data of the current frame and the next frame in the cell decomposition buffer; and transmitting only the even channel data of the current frame read in even channel time and the even channel data of the next frame being stored And if the data read from the cell decomposition buffer is not the first data read after storing the data, odd-numbered channel data previously stored in the odd-numbered channel time is serviced and the steps are repeated until the last even-numbered channel Multi-frame reading room of cell decomposer in ATM network characterized by method. The method of claim 1, wherein the odd channel service comprises: receiving service requests for even and odd channels from the time location access unit; servicing data of an even channel previously stored in an even channel time; Channel decoding of the current frame and odd-numbered channel data of the next frame in the cell decomposition buffer, so that only the current frame data is serviced in the odd-numbered channel time, and the next frame data is serviced in the next frame And then repeating the steps up to the last odd channel. ※ Note: It is disclosed by the contents of the first application.