KR100257556B1 - Fitting device in atm system - Google Patents

Abstract

PURPOSE: An asynchronous transmission method matching device is provided to process multimedia data efficiently by processing real-time data and non real-time data separately. CONSTITUTION: On the occasion of transmission of non real-time data, after a non real-time ATM cell processing part(18) performs an ATM process of the non real-time data, an ATM cell multiplexing/demultiplexing part(10) multiplexes an output of the non real-time ATM cell processing part(18), and transmits the multiplexed data to an ATM network through a physical layer part(20). On the occasion of receipt of the non real-time data, after the physical layer part(20) converts receipt signals into ATM cell type signals, the ATM cell multiplexing/demultiplexing part(10) demultiplexes the receipt signals, and transmits non real-time ATM cell to a non real-time ATM cell processing part(18) among the demultiplexed receipt signals. On the occasion of transmission of real-time data, after an AAL(ATM Adaptation Layer )-5 processing part(14) and an AAL-1 processing part(16) processes the real time data in order to fit the real time data for an AAL, a real-time ATM cell ATM layer processing part(12) converts the real time data fitted for the AAL into an ATM cell format. After this, the ATM cell multiplexing/demultiplexing part(10) multiplexes output signals of the real-time ATM cell ATM layer processing part(12) with the non real-time ATM cell, and transmits the multiplexed data to an ATM network through the physical layer part(20). On the occasion of receipt of the real-time data, after the physical layer part(20) converts the receipt signals into the ATM cell format signals, the ATM cell multiplexing/demultiplexing part(10) demultiplexes the converted signals, and transmits the real-time ATM cell to the real-time ATM cell ATM layer processing part(12) among the converted signals.

Description

Asynchronous Transmission Matching Device

The present invention relates to an asynchronous transfer method matching device. More specifically, an ATM (Asynchronous Transfer Mode) terminal accesses a Broadband Integrated Services Digital Network (hereinafter referred to as B-ISDM) to efficiently provide multimedia services. An asynchronous transmission matching device is provided.

In general, the ATM matching device analyzes the ATM cell signals from the B-ISDN network and delivers them to the system control unit, media processing unit, and user of the ATM terminal. Perform network connection function

Here, the ATM terminal means a multimedia terminal that efficiently provides a multimedia service using B-ISDN as a transmission medium. Ultimately, the ATM terminal is an interactive communication service such as a video call or a video conference, and an on-demand video service. It aims to provide various image search services such as Demand (VOD), broadcast services, and the like.

The conventional ATM matching device does not have a real-time data port, but has a structure for transmitting and receiving all data through the PC system bus. In this case, the source or the receiver of multimedia data such as an MPEG encoder or an MPEG decoder is provided. Sending and receiving multimedia data through the PC system bus is in a situation where real-time services cannot be provided.

Accordingly, an object of the present invention is to provide an asynchronous transmission method matching device configured to efficiently process multimedia data by separating real-time data and non-real-time data and processing the same.

In order to achieve the above object, according to a preferred embodiment of the present invention, multiple real-time ATM cell source and non-real-time ATM cell source multiplexed ATM cell header information and checks the real-time service by checking only ATM cell header information. ATM cell multiplexing / demultiplexing means for extracting a supported ATM cell, and only the ATM cell payload from the ATM cell multiplexing / demultiplexing means to the AAL-5 processing means or AAL-1 processing means. ATM cell ATM layer processing means for converting the real-time data from the AAL-5 processing means or AAL-1 processing means into an ATM cell form and transferring the same to the ATM cell multiplexing / demultiplexing means; Generates a cell and delivers it to the ATM cell multiplexing / demultiplexing means, and transmits system control information and user data information in a non-real-time ATM cell from the ATM cell multiplexing / demultiplexing means. ATM cell processing means for screening and outputting the ATM cell to the ATM cell multiplexing / demultiplexing means, and transmitting the ATM cell to the ATM network, and converting the signals transmitted through the ATM network into the form of an ATM cell, thereby multiplexing / reverse the ATM cell. There is provided an ATM matching device comprising physical layer processing means for transferring to multiplexing means, and control means connected to the respective means for controlling the respective means.

1 is a protocol stack structure employed in an asynchronous transmission method (ATM) matching device according to an embodiment of the present invention.

2 is a block diagram of an asynchronous transmission method matching device according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

10: ATM cell multiplexing / demultiplexing unit 12: ATM cell ATM layer processing unit

14: AAL-5 processing unit 16: AAL-1 processing unit

18: ATM cell processing unit 20: physical layer processing unit

22: PC system bus processing unit 24: control unit

The asynchronous transmission method matching device according to the embodiment of the present invention configured as described above has a feature that improves data processing performance and facilitates future function by adopting a structure different from conventional products. The principle is explained as follows.

First, the ATM matching device according to the embodiment of the present invention has a structure that can be used by connecting to a terminal having a PC (Personal Computer) as a platform or using a dedicated terminal.

Second, in case of PC platform terminal, such as audio and video are required in real time, data with large bandwidth saves bus resource of PC by using external bus without using PC LOCAL BUS.

Third, it enables the transmission and reception of protocol data such as Digital Storage Media Command & Control (DSMCC), H.245, IP over ATM, and Local Area Network Emulation (LANE) through the system bus of the PC.

Fourth, it accepts international standards and maintains compatibility with developed products that accept other international standards.

Fifth, it accepts AAL-1 and AAL-5 as AAL (ATM Adaptation Layer) type and implements core functions in hardware to process them in real time and at high speed.

Sixth, non-real-time ATM cells, such as OAM (Operation And Maintenance) cells, data cells, and ATM cells, which process fixed bit rates for transmitting multimedia data, are separated and processed as much as possible, thereby improving data processing efficiency.

Seventh, the logic for multiplexing the ATM cell is implemented in hardware.

Certain ATM protocol stack functions, such as signaling and OAM, are terminated at the ATM matching device and have local processors in the ATM matching device for high speed processing. The local processor ported a real-time operating system (OS) to manage the ATM matching device's hardware and software, reducing the burden on the PC's processor, improving multitasking capabilities and increasing system efficiency.

It has a PCI (Peripheral Component Interface) bus, but video and audio signals for video telephony codecs and VODs are connected to each board through an external bus without using the PCI bus. This saves resources on the system bus to achieve non-delay processing of various control messages and facilitates processing of the audio / video signals that are finally displayed through the overlay board. PCs can perform protocols such as DSMCC, H.245, IP over ATM, and LANE to communicate with the outside world through PCI buses and ATM matching devices.

For future integration with moving picture expert group-2 (MPEG-2) decoders and system control hardware, high performance, low power and low glow logic, and local boards are 32-bit micro A controller was used. The chips used in the ATM and AAL-5 layers of the PHY layer and the non-real-time ATM cell were used. In addition, the logic for processing AAL-1, AAL-5, and ATM layer of real-time ATM cells is designed using VHDL (VLSI Hardware Description Language).

The B-ISDN User Network Interface (UN) connection specification specified in the Recommendation of ITU-T SG13 was accepted to maintain compatibility with other HAN / B-ISDN development products. Among the types of ATM application layer, the audio / video signal used in the videophone codec is transmitted / received by AAL-1, and the AAL-5 is used for transmitting / receiving audio / video signals and other control signals for VOD and data on the PC.

The ATM matching device has a media processing unit and a system control unit as an upper module, and a B-ISDN Sb interface as a lower module.

The interface between the system control unit and the ATM matching unit uses a PC's expansion bus (PCI bus), and the ATM interface module within the system control unit to allow the system control unit to treat the ATM matching unit as one device under its management. -Application Program Interface) and device driver.

The signal between the media processing unit and the ATM matching unit is an audio / video stream that requires compressed and multiplexed real-time processing.

The interface with the media processing unit must satisfy the conditions necessary for the media processing unit to stably receive the data to be transmitted, and conversely to deliver the media signal transmitted through the network to the upper level.

Since the media processing unit is implemented in the form of an expansion board in the PC like the ATM matching unit, the physical connection between them is designed in the form of a feature connector. The end of ATM matching board has Sb interface to connect with B-ISDN network device.

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

1 is a diagram illustrating a protocol stack structure employed in an ATM matching device according to an embodiment of the present invention, in which the protocol stack structure is composed of hardware and software.

Here, the hardware implementation is the PMD sublayer, the TC sublayer, the AAL-5 layer processing the VOD, and the AAL-1 layer processing the video telephony data, and the rest is implemented in software using a real-time OS. .

The protocol stack structure configured as described above provides a video call as a service for AAL-1 and a VOD as a service for AAL-5.

Non-real-time data signals, except real-time data and signaling signals, are transmitted to the ATM network through the AAL layer, ATM layer, TC sublayer, and PDM sublayer during transmission, and the reverse process is performed upon reception.

In addition, data for signaling uses SALL, which is an AAL for signaling, and uses SSCF and SSCOP corresponding to SSCS of AAL 5.

2 is a block diagram of an ATM matching device according to an embodiment of the present invention. The embodiment of the present invention is a physical layer processing unit 20 connected to the ATM network so as to be transceivable with each other, and the physical layer processing unit 20 The ATM cell multiplexer / demultiplexer 10 connected to the transmitter / receiver and the ATM cell multiplexer / demultiplexer 10 are capable of transmitting and receiving to and from the AAL-5 processor 14 and the AAL-1 processor 16. A non-real-time ATM cell processor 18 coupled to the real-time ATM cell ATM layer processor 12 and the ATM cell multiplexer / demultiplexer 10 and the PC system bus processor 22 so as to be capable of transmitting and receiving each other. And a control unit 24 connected to the respective means 10, 12, 14, 16, 18, 20, 22 to control the operation of the apparatus as a whole.

Here, the ATM cell multiplexer / demultiplexer 10 is composed of an ATM cell multiplexer (not shown) and an ATM cell demultiplexer (not shown) to perform an ATM cell multiplexing function and an ATM cell demultiplexing function.

The ATM cell multiplexing function refers to the ATM cells generated by the non-real-time ATM cell processing unit 18 and the real-time ATM cell ATM layer processing unit 12 as a single ATM cell stream and transmitted to the physical layer processing unit 20. It means function.

In addition, the ATM cell demultiplexing function means that the real-time ATM cell ATM layer processing unit detects real-time ATM cells according to an ATM header table value previously assigned among the ATM cells received from the physical layer processing unit 20 ( 12) and the remaining cells mean a function of transmitting to the non-real-time ATM cell processing unit 18.

The ATM cell ATM layer processor 12 carries real-time data on the payload portion of an ATM cell and transmits the ATM cell header using a pre-assigned VCI, VPI value, etc., in case of transmission. The ATM header is transferred to the ATM cell multiplexer in the unit 10, and when received, the ATM header portion is extracted from the ATM cell received from the ATM cell demultiplexer in the ATM cell multiplexer 10, and the remaining ATM payload is analyzed. The part is transferred to the AAL-5 processing unit 14 or AAL-1 processing unit 16.

The AAL-5 processing unit 14 extracts the pure MPEG-2 TS stream from the AAL-5 CPCS-PDU received from the ATM cell ATM layer processing unit 12 and receives the MPEG-2 TS (Transport Stream) decoder. In case of transmission and transmission, the real-time data generated from the MPEG-2 TS encoder is converted into a CPCS-PDU, and the CPCS-PDU is divided and transmitted to the ATM cell ATM layer processing unit 12.

The AAL-1 processing unit 16 processes the AAL-1 function of the AAL layer. The AAL-1 transmitter (not shown) uses the SRTS (Synchronous Residual Time Stamp) function to transmit information about a source clock. Generates a segmentation and reassembly (SAR) header of bytes, and the AAL-1 receiver (not shown) examines the SAR header of the received cell to determine whether it is a lossy cell, a misinserted cell, or a normal cell. The cell is discarded and the dummy data is sent in case of a lost cell, and the cell payload in case of a normal cell is sent upward. In addition, the clock information on the source side is recovered by using the received RTS (Residual Time Stamp) value.

The ATM cell processing unit 18 transmits AAL-5 CPCS-PDU (Common Part Convergence Sublayer-Protocol Data) data to be transmitted to an ATM cell among user data transferred through a PCI bus or user data stored in a local SRAM under its management. Unit) and segment it to map it to an ATM cell and make it in the form of an ATM cell or vice versa. Data to be cellized in this module via the PCI bus is transmitted at high speed through the direct memory access (DMA) function of the PC system bus processor 22.

The physical layer processing unit 20 receives an ATM cell from an upper ATM cell multiplexing / demultiplexing unit 10, attaches a HEC (Header Error Control) byte, configures a transmission frame, and transfers it to an ATM network, and vice versa. Performs a receiving function, which is a process performed in the order of.

In addition, the physical layer processing unit 20 generates and confirms HEC, extracts cell boundaries, generates and confirms transmission frames, generates and processes physical layer transmission overhead, transmit frame mixing and demixing, idle cell generation and removal, clock and data. Perform functions such as restoring it.

The PC system bus processor 22 is PCI Local Bus Spec. It interfaces with the host system according to PCI standard compliant with Rev 2.0, and supports bus master, bus slave, and DMA functions.

In particular, the PC system bus processing unit 22 is to transfer the burst data between the PCI bus host and the non-real-time ATM cell processing unit 18 as a main function, the PCI bus host through the PC system bus processing unit 22 The internal resources of the real-time ATM cell processing unit 18 may be accessed, and the non-real-time ATM cell processing unit 18 may likewise access the resources of the PCI bus host.

The control unit 24 controls and manages hardware devices of the ATM matching apparatus and executes a part of ATM protocols such as signaling and OAM implemented in software on a real-time OS.

On the other hand, the AAL-5 processing unit 14 has a CBR input / output port (not shown) for AAL5, and the AAL-1 processing unit 16 has a CBR input / output port (not shown) for AAL1. It is connected with the codec for multimedia.

Next, a description will be given of the operation of the ATM matching device according to an embodiment of the present invention configured as described above.

First, the signal processing operation according to the transmission of the non-real time data will be described.

The non-real-time data to be transmitted is generated by a PC system bus (not shown) or the control unit 24. The data generated by the PC system bus is transferred to the non-real-time ATM cell processor 18 through the PC system bus processor 22. ), And the data generated by the control unit 24 is directly transmitted to the non-real-time ATM cell processing unit 18.

The ATM cell processing unit 18 performs ATM processing for transmitting the transmitted non-real-time data, and is then transmitted to the ATM cell multiplexing / demultiplexing unit 10 to perform multiplexing and then physical layer processing unit 20. Is transmitted to the ATM network.

Next, the signal processing operation according to the reception of the non-real time data will be described.

The received signals received from the ATM network are converted into ATM cells by the physical layer processing unit 20, and then demultiplexed by the ATM cell multiplexing / demultiplexing unit 10. The ATM is transmitted to the processing unit 18.

Thereafter, data for processing in the PC system is transferred to the PC system bus processor 22, while data for performing maintenance and management functions such as an OAM cell are transferred to the controller 24.

Next, the signal processing operation according to the transmission of real-time data will be described.

Real-time data are inputted to the CBR I / O port for AAL5 when performing AAL5 processing and transmitted, and inputted to the CBR I / O port for AAL1 when performing AAL1 processing.

The real-time data input as described above are AAL processed by the AAL-5 processing unit 14 and the AAL-1 processing unit 16, and then transferred to the real-time ATM cell ATM layer processing unit 12 to perform the ATM layer processing. .

In this way, the real-time ATM cells converted into the form of ATM cells are transmitted from the ATM cell multiplexer / demultiplexer 10 to the ATM network through the physical layer processor 20 through a multiplexing process with the non-real-time ATM cell. do.

Finally, the signal processing operation according to the reception of the real-time data will be described.

Received signals received from an ATM network are converted into ATM cells by the physical layer processing unit 20 and then demultiplexed by the ATM cell multiplexing / demultiplexing unit 10, and then determined to be real-time ATM cells. The ATM cell is transferred to the ATM layer processing unit 12.

After the ATM layer processing unit 12 performs the ATM layer processing, the ATM cell is transferred to the AAL-5 processing unit 14 and the AAL-1 processing unit 16 according to the required AAL layer processing. The AAL-5 processing unit 14 The real-time data through the AAL5 CBR input / output port (not shown) is transmitted to the MPEG codec side, while the real-time data through the AAL-1 processing unit 16 is used for video telephony through the CBR input / output port (not shown) for the AAL1. It is passed to the codec side.

According to the present invention as described above, by processing the real-time data and non-real-time data separately, not only improves the efficiency of real-time data processing in the ATM matching device, but also does not transmit multimedia data through the system's host bus separately. Dedicated parals are handled via the bus for flexibility and extensibility.

That is, according to the present invention, it is possible to easily cope with the change in the number of users of the multimedia service, to simply perform the data processing of the multimedia service to increase the data processing efficiency, and to save the system bus resources of the host system. Able to know.

On the other hand, the present invention is not limited only to the above-described embodiments, but may be modified and modified without departing from the scope of the present invention. Such modifications and changes should be considered to be within the scope of the following claims.

Claims (1)

ATM cell multiplexing / demultiplexing means for multiplexing ATM cells from multiple real-time ATM cell sources and non-real-time ATM cell sources, and extracting ATM cells supporting real-time services by only checking ATM cell header information; Real-time from the ATM cell multiplexing / demultiplexing means Delivers only the ATM cell secondary board to the AAL-5 processing means or AAL-1 processing means from the AAL-5 processing means or AAL-1 processing means. ATM layer processing means for converting the real-time data of the data into the form of an ATM cell and delivering the ATM cell multiplexing / demultiplexing means, and generating a non-real-time ATM cell and delivering the ATM cell multiplexing / demultiplexing means. ATM cell processing means for sorting and outputting system control information and user data information from a non-real time ATM cell from said ATM cell multiplexing / demultiplexing means, and said ATM cell multiplexing / demultiplexing number; A physical layer processing means for receiving an ATM cell and transmitting the received ATM cell to an ATM network, converting the signals received through the ATM network into an ATM cell, and transmitting the converted ATM cell to the ATM cell multiplexing / demultiplexing means; And a control means for controlling the respective means.

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