KR970008680B1 - Terminal device for asynchronous transmission mode - Google Patents

Abstract

The apparatus reduces the number of memories which are used in transmitting the received data from ATM layer to ATM adaption layer. The apparatus includes an ATM layer processing unit(11), a FIFO memory(12) which saves and outputs data in user information blocks, which are outputs of the ATM layer processing unit, by a cell unit, ATM adaption layer type precessing units(16) which process the ouput data of the FIFO memory with a relevant service requested by user.

Description

Terminal device for asynchronous transmission mode

Figure is a block diagram of a terminal device for asynchronous transmission mode according to the present invention.

* Explanation of symbols for main parts of the drawings

11: ATM (Asynchronous Transfer Mode) layer processing unit

12: First in, first out (FIFO) 16: AAL (ATM Adation Layer) processing unit

13: AAL-1 type processor 14: AAL-3 / 4 type processor

15: AAL-5 type processor

The present invention relates to a terminal device for an asynchronous transfer mode (hereinafter referred to as ATM), and is particularly used for transferring received data from an ATM layer to an AAL (hereinafter referred to as AAL to an ATM adaptation layer). A terminal device for an asynchronous transmission mode for reducing the number of memory to be.

ATM terminal device is a device using ATM communication method which is a special type of packet type delivery method using Asynchronous Time Division Multiplexing (ATDM), which has emerged as an implementation of Broadband Integrated Services Digital Network (BISDN). In the case of the receiving side, the ATM terminal apparatus processes call control, connection control information, and user through a process of a physical layer, an ATM layer, an AAL, and a higher layer protocol for data transmitted in a cell unit of 53 bytes. Performs information transfer processing.

The 53 byte unit is divided into 48 bytes of payload space (or user information section) and 5 bytes of header section, as is well known. As such, the information transmitted using the header section among the data of the cell unit divided and transmitted is analyzed in the ATM layer and used to control the general flow on the receiving side including the demultiplexing function of the cell. The user information transmitted by the control is controlled by the header information analyzed in the ATM layer and transmitted to the corresponding AAL. In this case, the user information is not directly transmitted from the ATM to the AAL, but through the memory corresponding to the AAL. In other words, each ATM terminal has a dedicated memory in each AAL to be used, and passes through the AAL dedicated memory connected between the ATM layer and the corresponding AAL in order to transfer user information transmitted from the ATM layer to the corresponding AAL. As described above, the conventional ATM terminal apparatus has the same number of memories as the number of AALs between the ATM layer and the AAL, and thus, the hardware is not only bulky but also increases the price of the system.

Accordingly, an object of the present invention is to provide an ATM terminal apparatus for reducing the number of memories used between an ATM and an AAL in a terminal apparatus using an ATM communication method.

In order to achieve the above object, an apparatus according to the present invention is a terminal apparatus for processing data received by asynchronous transmission mode based on a cell transmitting data by dividing an area into a header section and a user information section. ATM layer processing unit for ATM layer processing on received data, memory for storing and outputting data in the user information section output from the ATM layer processing unit by cell unit, header section analyzed by ATM layer processing of ATM layer processing unit And an AAL processing unit having at least one AAL type for adaptively processing the data output from the memory controlled by the data in the memory to the corresponding service required by the user.

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

The ATM terminal device that transmits data by the ATDM method processes data in the order of higher layer protocol, AAL, ATM layer and physical layer at the time of transmission, while receiving, physical layer, ATM layer, AAL and higher layer as described above. Data processing in the order of layer protocol.

The illustrated figure relates to an ATM terminal device that performs a reception function, wherein data received in units of cells is transmitted through a physical layer, and an ATM layer processing unit 11 and an ATM layer processing unit for ATM layer processing. 11) First In First Out (FIFO) for first-in first-out of the data in the user information section outputted in cell units, and the data output from the first-in first-out buffer 12 from the ATM layer processing unit 11. An AAL processing section 16 is provided for performing AAL processing of the type enabled by the output enable control signal.

Referring to the operation of the embodiment of the present invention configured as described above are as follows.

When data is applied in units of cells (data transmission area divided into a user information section and a header section) through the physical layer, the data is transmitted to the ATM layer processing unit 11.

The ATM layer processing unit 11 transmits the data transmitted in the user information section to the first-in, first-out buffer 12, which will be described later, and analyzes the data transmitted in the header section as described above. Outputs a control signal to control the demultiplexing function. In particular, it identifies the AAL type (Type) for the data currently applied by analyzing the VPI (Virtual Path Identifier) and VCI (Virtual Channel Identifier) information transmitted using the header section. AAL type information transmitted through VPI and VCI is allocated through a call setup process performed in a higher layer protocol at the time of transmission, which is set based on a service request signal of a user's desired type.

The first-in-first-out buffer 12 first-in-first-outs the 48-byte data applied from the ATM layer processing unit 11 in 53-byte units. That is, the data applied from the ATM layer processing unit 11 is stored during the 53-byte processing period, and then transferred to the AAL processing unit 16 to be described later during the next 53-byte processing period.

The AAL processing unit 16 includes an AAL-1 type processor 13, an AAL-3 / 4 type processor 14, and an AAL-5 type processor 15, and stores the user information data read from the first-in, first-out buffer 16. This is to adaptively process the user into a desired service type. In this case, the AAL-1 type delivers service data units (SDUs) of equal bit rate at the same bit rate, transfers time information between information sources and destinations, recovers errors, and displays unrecoverable errors. AAL-3 / 4 type transmits service data of Class C and D (variable C and D among A ~ D types classified according to whether or not the bit rate is constant, real-time capability, connectivity, etc.) To provide. AAL-5 type simplifies the function of AAL-3 / 4 type and provides high speed data transfer function.

The processors 13, 14, and 15 for processing the three types of services provided as described above are only processors that process a corresponding service based on an analysis result of the VPI and VCI information processed by the ATM layer processor 11. Is enabled. That is, when the currently authorized cell information is analyzed as data corresponding to the AAL-1 type of service, the ATM layer processor 11 enables the AAL-1 type processor 13 to be read from the first-in, first-out buffer 12. Data is supplied to the AAL-1 type processor 13. The AAL-1 type processor 13 processes the data in the corresponding service mode and transmits the data to the upper layer protocol.

As described above, the ATM terminal apparatus has a single memory and is configured to transmit data to a plurality of AAL types provided in order to satisfy a variety of service requirements of the user. Has the effect of down.

Claims (3)

A terminal apparatus for processing received data in an asynchronous transmission mode based on a cell transmitting data by dividing an area into a header section and a user information section, based on an asynchronous transmission mode (ATM) layer. An asynchronous transmission mode hierarchy processing unit for processing, a memory for storing and outputting data in the user information section outputted from the asynchronous transmission mode hierarchy processing unit on a cell basis, and the asynchronous transmission mode hierarchy processing of the asynchronous transmission mode hierarchy processing unit Asynchronous transmission mode adaptation having at least one asynchronous transmission mode adaptation layer (AAL) type, which is controlled by the data in the header section analyzed by the controller and adapted to process the data output from the memory to the corresponding service requested by the user. Include hierarchical processing unit Asynchronous transfer mode communication device for that feature. The terminal apparatus as claimed in claim 1, wherein the memory comprises a buffer for processing data output from the layer processing unit for the asynchronous transmission mode by a first-in first-out method. The asynchronous transmission mode adaptation layer (AAL) of claim 1 or 2, wherein the asynchronous transmission mode adaptive layer processing unit is controlled by the asynchronous transmission mode layer processing unit. Terminal type device for asynchronous transmission mode, characterized in that only the type is enabled.