KR20030069671A - Apparatus and method for transmitting cell in a telecommunication system - Google Patents

Abstract

PURPOSE: A device for transmitting a cell in a communication system and a method therefor are provided to give channel identifiers to each cell, and to minimize the number of connection lines between a BTS and a BSC, thereby implementing an efficient operation of an ATM public network. CONSTITUTION: A channel interface card(104) of a BTS(100) switches transmission cells added with virtual paths and channel identifiers to information inputted from a channel card(102), and transmits the transmission cells to a public ATM network(106). A channel interface card(110) of a BSC(108) classifies the transmission cells inputted from the public ATM network(106) into the virtual paths and virtual channels according to the channel identifiers, and outputs the classified transmission cells.

Description

APPARATUS AND METHOD FOR TRANSMITTING CELL IN A TELECOMMUNICATION SYSTEM}

A cell transmission apparatus and method in a communication system.

The demand for the Internet and image data is exploding in communication systems. Thus, the demand for a permanent virtual channel (PVC) between a base station and a base station controller in a communication system increases. In order to solve this problem, an end-to-end access line is required, which requires as many connection lines as end-to-end access lines. For example, if data related information of a channel card of a base station is transmitted through PVC through a channel interface of the base station controller, the number of access lines passing through the ATM public network will increase, causing service providers to increase maintenance costs. There was a problem that could be.

Accordingly, an object of the present invention is to provide an apparatus and a method capable of reducing the number of access lines passing through an ATM public network.

The present invention for achieving the above object, a communication system having a channel card and the AMT public network to add a virtual channel and a virtual path to the information received from the mobile station and output through a plurality of permanent virtual channel access lines A cell transmission apparatus, comprising: a channel interface unit of a base station for switching a transmission cell having the virtual path and a channel identifier added to each piece of information received from the channel card, and outputting the switched cell to the AT public network; And a channel interface unit of a base station controller for receiving the received transmission cell classified into the virtual path and the virtual channel according to the channel identifier.

1 is a block diagram of a communication system and AMT public network according to an embodiment of the present invention

2 is a diagram showing the format of AMT cell according to an embodiment of the present invention;

3 is a block diagram of a base station channel card according to an embodiment of the present invention

4 is a diagram illustrating data stored according to priority in a DS according to an embodiment of the present invention.

5 is a timing diagram of a DS according to an embodiment of the present invention.

6 illustrates a transmission algorithm according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. If it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed descriptions thereof will be omitted.

1 is a block diagram of a communication system according to an embodiment of the present invention.

Referring to FIG. 1, a base station (BTS) 100 is composed of a channel card and a channel interface card 104 of the base station. The base station 100 serves as an AAL2 engine of the channel interface unit 104 of the base station. The channel card 102 adds a virtual channel (VC) and a virtual path (VP) to the information received from the mobile station and outputs it to the channel interface unit 104 of the base station through a plurality of PVC access lines. . The channel card 102 implements a DSP. The PVC connection line is classified as follows. The PVC connection line 1 is between the channel card 102 and the channel interface 104 of the base station. The PVC between the channel card 102 and the channel interface 104 of the base station has a plurality of connection lines. The PVC connection line 2 is between the channel interface unit 104 of the base station and the channel interface unit 110 of the base station controller. The PVC between the channel interface unit 104 of the base station and the channel interface unit 110 of the base station controller has a few PVC connection lines. The PVC connection line 3 is between the channel interface unit 110 of the base station controller and the channel card 1 (AS1A: 114). The PVC between the channel interface unit 110 of the base station controller and the channel card 1 (AS1A: 114) has a plurality of connection lines. The PVC connection line 3 is between the channel interface unit 110 of the base station controller and the channel card 2 (TCLA: 116). The PVC between the channel interface unit 110 of the base station controller and the channel card 2 (TCLA) 116 has a plurality of connection lines. The channel interface unit 104 of the base station switches the received information and outputs the received information to the ATM public network 106. In this case, in order to transmit information input from a plurality of PVC access lines to a few PVC access lines, a VP and a channel identifier (CID) are added to each information. The AT public network 106 transmits the received information (cell) to the channel interface unit 110 of the base station controller (BSC) 108. The base station controller 108 implements the same DSP as the base station 100. The channel interface unit 110 of the base station controller switches and classifies the received information to the channel card 1 (AS1A: 114) or the channel card 2 (TCLA: 116) through the switch 112. At this time, the classification classifies each information into a virtual path and a virtual channel according to channel identification (CID).

2 is a diagram illustrating a format of an AT cell according to an embodiment of the present invention.

2 shows the AT cell header 200, the channel identifier (CID) 210, the start bit 240, the end bit 250, the LEN (Length: 260), the payload (220), and the CRC 230. It consists of). It informs the beginning and the end of a packet to transmit data such as messages and signaling or traffic. In particular, in the case of the data to be terminated, the CRC 230 field is set and the DSP calculates the channel card 102 of the base station BTS 100 and the channel card 1 of the base station controller BSC 108 (AS1A: 114). Control errors in the liver.

The payload 220 is variable and is variable within a maximum of 45 bytes by carrying the actual information. The channel identifier (CID) 210 uses a value from 1 to 255 as an AAL2 packet identifier. Channel identifier = 0 is not used to avoid confusion with "all 0" used for unused payload 220, and 2 to 7 are allocated for layer management peer-to-peer procedure. have. Therefore, CID for transmitting AAL2 user traffic can be used from 8 to 255. The channel identifier 220 value for the AAL2 user is set by AAL2 signaling when the AAL2 channel is set.

The LEN 260 indicates the length of the AAL2 packet payload 220. The default value is 45 EH, which is 64 bytes, but in order to avoid implementation complexity, it is defined as 45 bytes in CS-1 (Capability Set-1). have.

The AAL2 engine of the channel interface unit 104 of the base station that enters the AMT public network of the base station 100 and transmits the original data of the upper (BTS Cell format) format of the cell in the ATM public network ) Translates the connection table of the virtual path (VP) / virtual channel (VC) to the read virtual path, the virtual channel, and the channel identifier (CID). In order to minimize the number of virtual paths / virtual channels of the E1 / T1 link so that the number of available virtual paths / virtual channels may enter the public ATM network, the base station 100 assigns a channel identifier inside the cell. A separate translation table is configured to give the channel identifier therein, and an access circuit table is configured for this. For example, an ATM cell input1 is VP = 100 and VC = 50, an ATM cell input2 is VP = 110 and VC = 51, an ATM cell input3 is VP = 120 and VC = 52, and an ATM cell input4 is When VP = 130 and VC = 50, the VP / VC of the cell to be transmitted to the public ATM network, which is converted, reads and modifies the access circuit table.

The four inputs are converted into one VP and VC, and each input column is divided into CIDs. For example, VP = 50 and VC = 60 are used as they are, and a channel identifier (CID) for each input is assigned. For example, by modifying CID = 10, CID = 11, CID = 12, CID = 13, the VP and VC available in the ATM public network are minimized.

3 is a block diagram of a base station channel card according to an embodiment of the present invention.

Referring to FIG. 3, the HOST CPU 300 transmits payload data to the base station controller 108 to a memory MEMORY 310, and provides virtual path / virtual channel information, that is, buffer pointer length spacing information ( Information such as rate is managed by the buffer descriptor (BD: 320). To handle spacing, H / W uses the output of Buffered serial Tx port as interrupt and also applies Frame pulse and serial clk of basic TDM.

The DS 330 monitors the buffer descriptor at a predetermined time. The DS 330 processes the message to be transmitted as shown in FIG. 2 and stores the message in the internal memory 340.

Inside the internal memory, there is a Tx pre Queue 350 that stores data to be transmitted and a left queue 360 that remains untransmitted.

4 is a diagram illustrating data stored according to priority in a DS according to an embodiment of the present invention.

Referring to FIG. 4, if three data to be transmitted are generated, the transmission speed should be adjusted and transmitted. For this purpose, in the case of CH1 (400), the memory is listed according to spacing in the (F000) address of memory and the frame size interval of the time slot is listed. In the case of CH2 410 and CH3 420, the memory is arranged in the above-described method, and then the rate is adjusted to match the memory arrangement. That is, memory scanning is performed in units of priority, F000, F010, and F020 data is read to view the service ID, and the service ID is stored in the queue before transmission (Tx pre Queue) 430 as high priority. Store the untransmitted ID in the left queue (440) (part of tx_bufferd_serial_port_memory), and in the next steps F001, F011, and F021, the left queue (= LIFO: 440) remains the priority of the left queue (440) and the current one. Stores high data.

5 is a timing diagram of a DS according to an embodiment of the present invention.

5 is a timing diagram of the DS 330 interrupting and transmitting contents stored in a TX pre Queue of the DS 330 with reference to FIG. 4.

Frame sycn 510 is a signal that fits 16 cells into one frame. The TxD 530 is a signal indicating whether or not the portion of the display 520 is present. If the slot is filled, the TxD 530 is represented as "OF".

Interrupt (INT) 540 is a signal for the DS 330 to know the presence of the contents of the display 520 during operation. When this signal occurs, the DS 330 is stored in a TX pre buffer. Send the content.

Table 1 below summarizes various parameters used in the present invention.

pacing next_pacing_pointer Base_Buffer_Pointer Next_buffered_pointer Size DMA_next_pointer pacing_next_pointer CH1 3 0 * F02E 0 * F000 0 * F02D 1024 0 * 8010 0 * 2010 CH2 5 0 * F03E 0 * F010 0 * F03D 512 CH3 6 0 * F04E 0 * F020 0 * F04D 256

pacing is a parameter that each speed is made to space the different CHs. next_pacing_pointer is the next subaddress to be pacing. base_pacing_pointer is an address where data of each CH is stored. next_buffered_pointer is the next higher address to pacing. size is the total size of the CHs that can be stored. DMA_next_pointer is a pointer to the data corresponding to the transfer when transferring from DMA memory. pacing_next_pointer is a pointer used to bring pacing data from memory to DMA memory.

6 is a diagram illustrating a transmission algorithm according to an embodiment of the present invention.

Referring to FIG. 6, in step 600, the DSP 330 checks whether data to be transmitted has occurred. If data to be transmitted is generated as a result of the inspection, the DSP 330 performs step 610, and if data to be transmitted is not generated, repeats step 600.

In step 610, the DSP 330 first checks whether the stored data remains in the left queue. If the check result remains in the Left Queue, the DSP 330 performs step 620, and if not left in the Left Queue, performs step 630. In step 620, the DSP 330 applies FIFO (First In First Out) to store the first data received among the remaining data in a memory to be transmitted (Tx pre Queue) and proceeds to step 640.

In operation 630, the DSP 330 stores the data having the highest priority among the input data in a memory to be transmitted (Tx pre queue). Even if there is data coming in at the same time, the highest priority data is stored in the memory to be transmitted (Tx pre queue). In step 640, the DSP 330 checks whether there is remaining data. If there is remaining data, the DSP 330 performs step 650, and if there is no remaining data, the DSP 330 performs step 660.

In step 650, the DSP 330 stores the remaining data in a left queue and returns to step 610. In step 660, the DSP 330 checks whether an interrupt has occurred. If the check resulted in an interrupt, the DSP 330 proceeds to step 670 to transmit data to the ATM. If the interrupt does not occur, the DSP 330 repeats step 660.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

As described above, the present invention can minimize the number of access lines between a base station and a base station controller by assigning a channel identifier to each cell in a communication system, thereby providing efficient operation of the AMT public network, and allowing service providers to maintain maintenance costs. There is an advantage that can be reduced.

Claims (2)

A cell transmission apparatus in a communication system having a channel card and an ATM public network for adding virtual channels and virtual paths to information received from a mobile station and outputting them through a plurality of permanent virtual channel access lines. A channel interface unit of the base station for switching the transmitting cell to which the virtual path and the channel identifier are added to each information received from the channel card, and transmitting the switched cells to the public ATM network; And a channel interface unit of a base station controller for classifying and outputting the transmission cell received from the public ATM network into the virtual path and the virtual channel according to the channel identifier. A cell transmission method of a communication system for transmitting data through a plurality of permanent virtual channel access lines by adding a virtual channel and a virtual path to information received from a mobile station, A first step of checking whether stored data exists when data to be transmitted is generated; If there is no stored data as a result of the inspection, storing the data having the highest priority among the currently input data in a memory to be transmitted; A third process of storing the first input data in a memory to be transmitted if there is data stored as a result of the inspection; A fourth process of storing data left in the memory to be transmitted in a left queue; And a fifth process of transmitting data stored in the memory to be transmitted when there is no remaining data and an interrupt occurs.