KR20020067866A - The operation method of AAL 2/5 conversion module for the increase of transmission capacity in BSC-BTS interface of IMT-2000 service. - Google Patents

Abstract

PURPOSE: A system for operating and configuring an AAL2/5 conversion unit for the improvement of transmission efficiency in interoffice connection in IMT-2000 service is provided to reduce the quantity of logics for AAL2/5 conversion. CONSTITUTION: A system for operating and configuring an AAL2/5 conversion unit(2) for the improvement of transmission efficiency in interoffice connection in IMT-2000 service consists of a conversion control unit(1), the AAL2/5 conversion unit(2), a system access unit(3), and a transmission line access unit(4). The conversion control unit(1) issues a speech path control command for the transmission of subscriber information according to a radio subscriber's conversion address request generated from the AAL2/5 conversion unit(2) or a subscriber transmission request received from the transmission line access unit(4), and manages and monitors the state of information transfer. The AAL2/5 conversion unit(2) receives a conversion control command from the conversion control unit(1), makes the transmission line access unit(4) establish a speech path, and executes an AAL2/5 conversion processing function. The system access unit(3) receives AAL5-type data according to the control of the conversion control unit(1) and transfers the received data to the AAL2/5 conversion unit(2). The transmission line access unit(4) executes a function to establish an appointed speech path according to the command of the conversion control unit(1).

Description

The operation method of AAL 2/5 conversion module for the increase of transmission capacity in BSC-BTS interface of IMT-2000 service.}

Among the AALs for ATM transmission in the IMT-2000 system, AAL5 is processed in the base station, control station, and switching station, but when transmitting between stations, AAL5 is converted to AAL2 that can accommodate multiple subscribers at the same time. Its purpose is to drive efficiency

The present invention provides a means for performing efficient data transmission by converting to AAL2 between lines by increasing the line cost when the AAL5 is used in an IMT-2000 system that must process a large amount of high-speed information.

The present invention relates to an apparatus for processing data transmission between the base station and the control station, the control station and the switching station in the AAL2 method in which data transmission between the IMT-2000 networks is performed by ATM.

Looking at the prior art as follows. Since the IMT-2000 system applying the CDMA method must guarantee access to various multimedia media including image information and packet data information as well as voice information, a large amount of information transmission must be performed. ATM (ATM Adaptation Layer) is ATM (Asynchronous Transfer). At the top of the OSI (Open System Interconnection) reference model for transport, one ATM cell consists of 53 bytes in the AAL. The header occupies 5 bytes and the remaining 48 bytes contain data. Occupy. In the IMT-2000 system, various data processing is performed through AAL5 in the base station, the control station, and the switching center. However, various data transmissions through the AAL5 between the base station and the control station, the control station and the switching station bring inefficiency in circuit usage. For example, when data transmission is made through AAL5, as mentioned above, voice data (9-13 bytes) with a small amount of data, which is 48 bytes, must be transmitted even if empty bytes are generated when transmitted in one cell. There is inefficiency. That is, in case of AAL5, even if 48 cells of data cannot be filled in one cell, it has brought irrationality (accepting only one subscriber). In the prior art, it has been used by converting to AAL2 / 2 'only in software, but since 2' (2 prime) is not standardized, the system internalization is disadvantageous and there is no device of 2prime processing and the speed is slow. . Also abbreviation for International Telecommunications Union Telecommunication Standardization Sector (ITU-T). An international organization that develops global standards for communications technology. The only proposed AALs in the internationally proposed ATM layer by ITU-T (which previously performed what CCITT did) are AAL1, AAL2, AAL3 / 4 and AAL5.

First, AAL2 / 5 conversion requires a large amount of logic (more than 300,000 gates), reducing the amount of logic.

Second, due to the system characteristics, the delay should be small, but it is extremely difficult but the delay should be reduced.

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In order to achieve the above object, an AAL2 / 5 conversion apparatus, a conversion control apparatus, and a transmission path thereof must be configured. Hereinafter, exemplary embodiments thereof will be described in detail with reference to the accompanying drawings.

Fig. 1 is an overall configuration diagram to which the present invention is applied and shows a state in which an AAL2 / 5 converter is connected to a system connection device and a transmission line connection device to be interlocked under the control of a conversion control device. (2) consists of an AAL2 / 5 converter, (3) a system connection device, and (4) a transmission line connection device.

Among these, the conversion control device 1 receives subscriber information according to the conversion address request of the wireless subscriber originating from the AL2 / 5 conversion device 2 or the subscriber transmission request of the switching center and the base station received from the transmission line connection device 4. Instructs the path control command as a call for transmitting, and manages and monitors information transmission status. The AAL2 / 5 conversion device 2 receives a conversion control command for each subscriber information of the conversion control device to cause the transmission line connecting device 4 to set a call path and to perform AAL2 / 5 conversion. The system connection device 3 performs the function of receiving the AAL5 type data from the system and transferring the AAL5 type data to the AAL2 / 5 conversion device 2 under the control of the conversion control device 1, and the transmission line connection device 4 performs the conversion. In accordance with the command of the control apparatus 1, it performs a function of setting a designated call in connection with a call with a switching center or a base station.

Figure 2 shows the conversion process from AAL5 to AAL2

(5) UTOPIA I / F is a connection for exchanging ATM cells with external ATM devices.

(6) CAM (content-addressable memory) analyzes the header of AAL5 cell inputted through UTOPIA I / F and outputs internally necessary internal variables CN2, CN5, CID, and Matched.

(7) AAL5 Payload Buffer is a memory that stores only Payload in the input ATM cell and stores the internal variable CN5 output from (2) as the address.

(8) AAL2 Header Table stores header to be used for ATM cell converted to AAL2. It uses internal variable CN2 outputted from (6) as address.

(9) AAL2 Payload Buffer stores payload to be used for AAL2 converted ATM cell and uses internal variable CN2 outputted from (6) as address. The payload is stored in minicell units.

(10) AAL2 Cell Buffer stores ATM cells converted to AAL2.

(11) Matched Mux selects AAL5 cells that do not need to be converted and outputs them immediately without conversion. Use the internal variable Matched output from (6) to determine the conversion.

Fig. 3 shows a flow chart of the initialization software of the conversion unit from AAL5 to AAL2. The process of initializing the CAM memory and converting AAL5 cells into the AAL2 cells through the flow chart is described with explanation.

By hardware processing AAL5 to AAL2 and AAL2 to AAL5

First, by driving the strip mode converter, the delay time required for the conversion can be minimized.

Second, by maintaining the cell buffer function inside the converter, it is possible to maintain the serial and parallel conversion waiting time generated by the transmission line connection device.

Third, by simultaneously using RAM, SRAM, and internal FIFO, it is advantageous to click synchronization, and the logic amount can be reduced and flexible routing is possible.

Claims (2)

Figure 2 (5) to (11) is characterized by the operation operation sequence and configuration and operation method of the AAL2 converter Figure 3 (12) to (17) is characterized by the operation operation sequence, AAL2 conversion device configuration and operation method