KR100414655B1 - Apparatus and method for converting cell in wireless telecommunication system - Google Patents

Abstract

The present invention relates to an apparatus and method for cell conversion in a wireless communication system, wherein the AAL2 form is converted to AAL5 form and the AAL5 form is converted to AAL2 form in a wireless communication system. Maintains the advantage of AAL2 type, which increases the transmission width and trunk efficiency in communication with ATM cells, and each subsystem between the base station and the control station performs only AAL5 type communication so that the inside of the base station, the control station, and the core network In order to simplify the hardware of each internal subsystem, the state and control information required to convert an AAL5 type ATM cell into an AAL2 type ATM cell, and the state and control information required to convert an AAL2 type ATM cell to an AAL5 type ATM cell. Control means for generating a; First AAL5,2 converting means for verifying a header of the ATM cell and converting an AAL5 type traffic ATM cell to be AAL2 type ATM cell based on address translation control information under the control of the control means; And first AAL2 and 5 converting means for verifying the header of the ATM cell and converting an AAL2 type ATM cell to AAL5 type traffic ATM cell under the control of the control means based on the address translation control information. .

Description

Apparatus and method for converting cell in wireless telecommunication system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell conversion apparatus and a method thereof in a wireless communication system. In particular, the present invention relates to an ATM adaptation layer (AAL) 2 and a next generation mobile communication system such as International Mobile Telecommunication (IMT-2000) and Universal Mobile Telecommunications System (UMTS). An AAL5 type Asynchronous Transfer Mode (ATM) The present invention relates to an ATM adaptive layer 2 and 5 (AAL2 / AAL5) inter-conversion apparatus and method for inter-converting and transmitting a cell.

1 is an exemplary configuration diagram of a general wireless communication system, and shows an asynchronous wireless communication system (W-CDMA), and the asynchronous wireless communication system (W-CDMA) is a mobile station (a) and an asynchronous wireless access network (RAN) ( b) and between the wireless communication core network (e.g., GSM-MAP core network) (e).

Asynchronous wireless communication system (W-CDMA) is composed of a plurality of asynchronous radio access network (RAN) (b) connected to the wireless communication core network (e) through the Iu interface.

In Fig. 1, "Iu" is an interface between a wireless communication core network (CN) (e) and an asynchronous radio access network (RAN) (b), and "Iur" is an interface of an asynchronous radio access network (RAN) (b). Is a logical interface between a control station (RNC: Radio Network Controller) (d), and "Iub" represents an interface between the control station (RNC) (d) and the base station (Node-B) (c), respectively. On the other hand, "Uu" denotes an air interface between an asynchronous radio access network (RAN) b and a user equipment (UE) (a). Here, a base station (Node-B) (c) is a logical node responsible for radio transmission and reception from or to a mobile station (UE) (a) in one or more cells.

An asynchronous radio access network (RAN) (b) is composed of a control station (RNC) (d) and a base station (Node-B) (c), each base station (Node-B) (c) is one or more cells (cell) Is connected to the control station (RNC) d via the Iub interface.

The control station (RNC) (d) performs a combination / splitting function during handover between the base stations (Node-B) (c), and in the case of intercell handovers within the same base station (Node-B) (c), the combination / splitting The function may be performed by the control station (RNC) (d) or by the base station (Node-B) (c).

As described above, the asynchronous wireless communication system (W-CDMA) is a mobile station (UE) (a), a base station (Node-B) (c), a control station (RNC) (d) and the core network (CN) (e), etc. Comprising: between the base station (Node-B) (c) and the control station (RNC) (d), between the control station (RNC) (d) and the core network (CN) (e), the base station (Node-B) (c Each sub-system inside the control center (RNC) (d) and inside the core network (CN) (e) performs communication based on ATM. The ATM communication method consists of a physical layer, an ATM layer, an AAL layer, and a higher layer. The AAL layer is classified into AAL1 to AAL5 according to a service type. AAL2 is suitable for low speed, "Low-Rate, Short and Variable Length" packet transmission, sensitive to the time delays seen in wireless voice data transmission, while AAL5 is suitable for high speed, "High-Rate, Long and Variable Length". "It is suitable for packet transmission.

In asynchronous wireless communication system (W-CDMA), traffic data is serviced by an AAL2 type ATM cell, and control data is serviced by an AAL5 type ATM cell. The system is configured to handle both AAL2 type ATM cells and AAL5 type ATM cells at the base station (Node-B) (c), control station (RNC) (d) and core network (CN) (e). Since both the ATM cell and the AAL5 type ATM cell must be processed, there is a problem in that the hardware becomes complicated.

Therefore, in the current technical field, the AAL2 form is converted to the AAL5 form, and the AAL5 form is converted to the AAL2 form, in which bandwidth and trunk (Bandwidth) and trunk ( Trunk) Maintains the advantages of the AAL2 type to increase efficiency, and each subsystem between the inside of the base station and the inside of the control station performs only AAL5 type communication so that the inside of the base station Node-B (c) and the control station (RNC) (d) A way to simplify the hardware of each subsystem inside and inside the core (CN) (e) is essential.

The present invention has been proposed to meet the above-mentioned requirements, and in the wireless communication system, AAL2 form is converted to AAL5 form and AAL5 form is converted to AAL2 form to have a packet having a small size such as voice traffic of mobile communication. It maintains the advantages of AAL2 type, which increases the transmission width and trunk efficiency in communication with ATM cells, and each subsystem between the base station and the control station performs only AAL5 type communication, so that the base station, the control station, and the core network are inside. It is an object of the present invention to provide a cell conversion device and a method for simplifying the hardware of each subsystem.

1 is an exemplary configuration diagram of a general wireless communication system.

2 is a block diagram of an embodiment of a cell converter (AAL2 / AAL5 mutual converter) according to the present invention;

3 is a flowchart illustrating an operation of the AAL5,2 converter of FIG. 2 according to the present invention;

4 is a flowchart illustrating an operation of an AAL2,5 converter of FIG. 2 according to the present invention;

5 is an explanatory diagram showing the AAL5 and AAL2 protocol formats used in the present invention.

6 is an exemplary configuration of applying a cell conversion device according to the present invention to a next generation mobile communication system.

* Explanation of symbols for the main parts of the drawings

1: AAL5,2 converter 2: AAL2,5 converter

3: central processing unit 11, 23: utopia input matching unit

12,24: input buffer 13,25: multiplexer

14: AAL5,2 conversion unit 15,27: demultiplexer

16,28: output buffer 17,29: feedback output buffer

18,30: Utopia output matching unit 19,31: address conversion unit

20,32: cell storage 21,33: status, control storage

22,34: central processing unit matching unit 26: AAL2,5 conversion unit

In order to achieve the above object, the present invention provides a device for converting an AAL (ATM Adaptation Layer) type asynchronous transfer mode (ATM) cell, the state and control information required to convert an AAL5 type ATM cell into an AAL2 type ATM cell. And control means for generating state and control information necessary for converting an AAL2 type ATM cell into an AAL5 type ATM cell. First AAL5,2 converting means for verifying a header of the ATM cell and converting an AAL5 type traffic ATM cell to be AAL2 type ATM cell based on address translation control information under the control of the control means; And a first AAL2, 5 converting means for converting an AAL2 type ATM cell to be converted into an AAL5 type traffic ATM cell based on address translation control information by checking the header of the ATM cell under the control of the control means. Characterized in that made.

In addition, the present invention provides an apparatus for converting an AAL (ATM Adaptation Layer) type asynchronous transfer mode (ATM) cell, Utopia input matching means for receiving the ATM cell via the utopia bus; First storage means for storing at least one ATM cell received in the utopia input matching means; Multiplexing means for selectively outputting one of the output data of the first storage means or the output data of the feedback output buffer of an apparatus (AAL2, 5 conversion apparatus) for converting an AAL2 type ATM cell into an AAL5 type ATM cell; Second storage means for storing address translation control information; Third storage means for storing state and control information necessary for converting an AAL5 type ATM cell into an AAL2 type ATM cell; According to the state and control information, the header of the ATM cell selected and outputted by the multiplexing means is checked to determine whether to convert or bypass the type of the AAL5 type based on the address translation control information. AAL5,2 converting means for converting the traffic ATM cell into an AAL2 type ATM cell and bypassing the control ATM cell; Cell storing means for storing the type-converted AAL2 type ATM cell; And output means for outputting at least one AAL2 type ATM cell converted by the AAL5,2 conversion means according to an operation mode (normal mode or feedback mode).

In addition, the present invention provides an apparatus for converting an AAL (ATM Adaptation Layer) type asynchronous transfer mode (ATM) cell, Utopia input matching means for receiving the ATM cell via the utopia bus; First storage means for storing at least one ATM cell received in the utopia input matching means; Multiplexing means for selectively outputting one of the output data of the first storage means or the output data of the feedback output buffer of an apparatus (AAL5, 2 conversion apparatus) for converting an AAL5 type ATM cell into an AAL2 type ATM cell; Second storage means for storing address translation control information; Third storage means for storing state and control information necessary for converting an AAL2 type ATM cell into an AAL5 type ATM cell; According to the state and control information, the header of the ATM cell selected and outputted by the multiplexing means is determined to determine whether to convert or bypass the type of the AAL2 type, based on the address translation control information. AAL2,5 conversion means for converting an ATM cell into an AAL5 type traffic ATM cell, and bypassing the control ATM cell; Cell storage means for storing the type AAL5 type traffic ATM cell; And output means for outputting at least one AAL5 type traffic ATM cell converted by the AAL2,5 conversion means according to an operation mode (normal mode or feedback mode).

Meanwhile, the present invention provides a method of converting an ATM cell in the form of ATM Adaptation Layer (AAL), comprising: a first step of receiving an ATM cell through a utopia bus; A second step of selecting one of feedback output data of a device (AAL2, 5 conversion device) for converting a receiving ATM cell or an AAL2 type ATM cell into an AAL5 type ATM cell; Based on the state and control information required for converting the ATM cell to the AAL2 type ATM cell, the header of the ATM cell selected in the second step is checked to determine whether to convert or bypass the ATM cell, and then, based on the address translation control information. Converting the AAL5 type traffic ATM cell to AAL2 type ATM cell and bypassing the control ATM cell; And a fourth step of outputting the type-converted AAL2 type ATM cell according to an operation mode (normal mode or feedback mode).

In addition, the present invention provides a method for converting an ATM cell in the form of ATM Adaptation Layer (AAL), comprising: a first step of receiving an ATM cell through a utopia bus; A second step of selecting one of feedback output data of an apparatus (AAL5, 2 conversion apparatus) for converting a receiving ATM cell or an AAL5 type ATM cell into an AAL2 type ATM cell; According to the state and control information required to convert the AAL5 type ATM cell into the AAL2 type ATM cell, the header of the ATM cell selected in the second step is checked to determine whether to convert or type the address, and to control the address translation. Converting the AAL5 type traffic ATM cell to be type-converted based on the information into an AAL2 type ATM cell, and bypassing the control ATM cell; And outputting the type-converted AAL2 type ATM cell according to an operation mode (normal mode or feedback mode) .

The present invention relates to an adaptive layer 2 and 5 inter-conversion (AAL2 / AAL5) apparatus in an asynchronous transmission mode (ATM) network for translating and transmitting AAL2 and AAL5 types of ATM cells, and used in a base station, a control station, and a core network. Therefore, in the interval between the base station and the control station, and between the control station and the core network, the AAL2 form is converted to the AAL5 form, and the AAL5 form is converted to the AAL2 form. Each subsystem in the base station, the control station, and the core network is simplified, and a packet having a small size, such as voice traffic of a mobile communication, is converted into an AAL2 type ATM cell. In terms of communicating, it increases bandwidth and trunk efficiency.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a configuration diagram of an embodiment of a cell conversion device (AAL2 / AAL5 mutual conversion device) according to the present invention, and converts an AAL5 type ATM cell into an AAL2 type ATM cell (AAL5,2 conversion device 1) and AAL2. An AAL2 / AAL5 interconversion device for converting an ATM cell of the type into an AAL5 type ATM cell (AAL2, 5 converter 2).

As shown in FIG. 2, first, an AAL5,2 converting apparatus 1 for converting an AAL5 type ATM cell into an AAL2 type ATM cell includes a Utopia input interface unit for receiving an ATM cell through a Utopia bus. (11), an input buffer (FIFO) 12 for storing at least one ATM cell received in the utopia input matching unit 11, and output data of the input buffer 12 or an AAL2,5 converter (2). A multiplexer (MUX) 13 for selectively outputting one of the output data of the feedback output buffer 29, an address conversion unit (CAM) 19 storing address translation control information, and an AAL5 type. Selective output by the multiplexer 13 in accordance with a state storing a state and control information necessary for converting an ATM cell into an AAL2 type ATM cell, a state control register 21, and state and control information. Check and typecast or bypass the header of the ATM cell. The AAL5 type traffic ATM cell to be converted into an AAL2 type ATM cell based on the address translation control information of the address conversion unit 19, and the control ATM cell bypasses the AAL5, 2 conversion unit ( 14), the cell storage unit (DPRAM) 20 that stores the type-converted AAL2 type ATM cell, and the AAL2 type ATM cell converted by the AAL5 and 2 converting units 14 operate modes (normal). A demultiplexer (DEMUX) (15), an output buffer (output FIFO) (16), a loopback output FIFO (17), and a utopia output interface for outputting at least one, depending on the mode or feedback mode). The unit 18 is included.

The AAL2,5 converter 2 for converting an AAL2 type ATM cell into an AAL5 type ATM cell includes a Utopia input interface unit 23 for receiving an ATM cell through a Utopia bus, and a Utopia input. An input buffer (FIFO) 24 for storing at least one ATM cell received in the matching unit 23, and output data of the input buffer 24 or feedback output buffer 17 of the AAL5,2 converter 1; A multiplexer (MUX) 25 for selectively outputting one of the output data of the < RTI ID = 0.0 >), an address conversion unit (CAM) 31 which stores address translation control information, and an AAL2 type ATM cell. Check the header of the ATM cell selected and output by the multiplexer 25 in accordance with a state, a state control register 33, and a state and control information, which store state and control information necessary for conversion to a cell. To determine whether to typecast or bypass An AAL2 and 5 conversion unit 26 for converting the AAL2 type ATM cell to be converted into an AAL5 type traffic ATM cell based on the address conversion control information of the conversion unit 31 and bypassing the control ATM cell, The cell storage unit (DPRAM) 32 storing the converted AAL5 type traffic ATM cell, and the AAL5 type traffic ATM cell converted by the AAL2, 5 converting unit 26 are operated in normal mode or feedback. A demultiplexer (DEMUX) 27, an output buffer FIFO 28, a loopback output FIFO 29, and a UTOPIA output interface unit for outputting at least one, 30).

First, the functions of the respective components of the AAL5, 2 converter 1 will be described in more detail.

The utopia input matching unit 11 functions as a master or slaver of UTOPIA Level 1 or 2, and receives an ATM cell through a Utopia bus 101 operating at UTOPIA Level 1 or 2, thereby receiving an internal path. Write an ATM cell to the input buffer 12 via 102.

The multiplexer 13 selects one of the output data 103 of the input buffer 12 and the output data 104 of the feedback output buffer 29 in the AAL2,5 conversion device 2 to select the path 105. The data is output to the AAL5,2 converter 14 through.

The AAL5,2 converter 14 functions to convert from AAL5 (control) to AAL5 (control) and from AAL5 (traffic) to AAL2 according to the protocol conversion format of FIG.

When the AAL5,2 conversion unit 14 confirms that the ATM cell is received in the input buffer 12 or the feedback output buffer 29, 5 bytes of the ATM cell header portion of the input buffer 12 or the feedback output buffer 29 are determined. Reads and checks the HEC (Header Error Control, 8-bit) of the ATM cell header part, and if there is an error, reads the 48-byte ATM cell payload and invalidates the ATM cell. On the other hand, if there is no error, it is determined whether the ATM cell is AAL5 (traffic) or AAL5 (control). The VPI (Virtual Path Identifier, 8-bit) or VCI (Virtual Channel Identifier, Virtual Channel Identifier) 16 bits) to distinguish them.

In the case of AAL5 (control), when address translation is required, a new VPI / VCI and HEC are generated with reference to the address conversion unit 19 and written to the output buffer 16. However, if no address translation is required, the received ATM cell header is written to the output buffer 16. Then, 48 bytes of the ATM cell payload portion are read from the input buffer 12 and written to the output buffer 16.

On the other hand, in the case of AAL5 (traffic), a new VPI / VCI and HEC are generated and written to the cell storage unit 20 by referring to the address conversion unit 19 according to the VPI / VCI. Then, 48 bytes of the ATM cell payload portion is read from the input buffer 12, and according to the AAL2 standard (ITU-T, International Telecommunication Union-Telecommunication Standardization Sector I.363.2) ) (I.e. Offset Field, 6-bit), Sequence Number (1 bit), Parity (1 bit), and Common Part Sublayer (CPS) packet header (i.e., CID ( Channel Identifier, LI (Length Indicator, 6 bit), UUI (User to User Indication, 5 bit), HEC) and CPS-packet payload (i.e. CPS-INFO ( Common Part Sublayer Interface Data, 1..45 bytes)), that is, converted into an AAL2 cell composed of CPS-packets multiplexed in one ATM cell and recorded in the cell storage unit 20.

Thereafter, when the 53-byte ATM cell is configured, the cell storage unit 20 reads the stored AAL2 cell and writes it to the output buffer 16. At this time, if the 53-byte ATM cell is not configured and the timer is not terminated, the ATM cell is received. If the 53-byte ATM cell is not configured and the timer is expired, zero pad is added to the demultiplexer. According to selection of (15), a function is written to the output buffer 16 or the feedback output buffer 17.

The utopia output matching unit 18 functions as a master or slaver of the UTOPIA Level 1 or 2, and reads an ATM cell from the output buffer 16 and operates the Utopia Level 1 or 2 to operate the Utopia Bus 110. ) Transmits an ATM cell.

The central processing unit 3, which is an external device, knows the state of the AAL5,2 conversion device 1 by reading the information from the state and control storage unit 21 via the path 115 and the central processing unit matching unit 22. It is also possible to control the operation mode of the AAL5,2 converter 1 by recording the information in the state and control storage 21.

The central processing unit 3 sends the mode of operation of the utopia input matching unit 11 and the utopia output matching unit 18 to the state and control storage unit 21 via the path 115 and the central processing unit matching unit 22. By setting, the utopia input matching section 11 and the utopia output matching section 18 function as a master or a slaver of the UTOPIA Level 1 or 2.

In addition, the central processing unit 3 sets the operation modes of the multiplexer 13 and the demultiplexer 15, so that the normal mode or the loopback mode operation of the AAL5, 2 converter 1 is performed. To control. The normal mode of the AAL5,2 converter 1 represents an operation mode constituting the path (101 → 102 → 103 → 105 → 106 → 107 → 109 → 110), and the feedback mode is the path (101 → 102 → 103 → 105 → 106 → 108 → 204 → 205 → 206 → 207 → 209 → 210. The feedback mode of the AAL5,2 converter 1 is based on the base station, control station, core network test and between the base station and the control station of the next generation mobile communication system using the AAL2 / AAL5 interconversion device of FIG. Used for matching tests.

In addition, it is possible to set whether or not address conversion is required when converting from AAL5 (control) to AAL5 (control) in the AAL5 and 2 converter 14, and the timer end time can be set when converting from AAL5 (traffic) to AAL2. have.

The AAL5,2 converter 14 stores the HEC of the ATM cell header portion in the AAL5,2 converter 14 and stores the VPI / VCI in the state and control storage 21 when there is an error. Can be notified to the central processing unit 3 as an external device.

The central processing unit 3 controls the VPI / VCI address translation by recording the information in the address translation unit 19 via the path 116.

Now, the functions of the respective components of the AAL2,5 converter 2 will be described in more detail.

Utopia input matching unit 23 performs a master or slaver function of UTOPIA Level 1 or 2, and receives an ATM cell through a Utopia bus 201 operating at UTOPIA Level 1 or 2 Write ATM cells to input buffer 24 via path 202.

The multiplexer 25 selects one of the output data 203 of the input buffer 24 and the output data 204 of the feedback output buffer 17 in the AAL5,2 conversion device 1 to select the path 205. The data is output to the AAL2,5 converter 26 via the control unit.

The AAL2,5 converter 26 performs a function of converting from AAL5 (control) to AAL5 (control) and converting from AAL2 to AAL5 (traffic) according to the protocol conversion format of FIG.

When the AAL2,5 converter 26 confirms that the ATM cell is received in the input buffer 24 or the feedback output buffer 17, 5 bytes of the ATM cell header portion of the input buffer 24 or the feedback output buffer 17 are determined. Reads the HEC in the ATM cell header section and, if there is an error, reads the ATM cell payload 48 bytes to invalidate the ATM cell. On the other hand, if there is no error, the ATM cell identifies AAL2 or AAL5 (control) by checking the VPI or VCI of the ATM cell header.

In the case of AAL5 (control), when address translation is required, a new VPI / VCI and HEC are generated with reference to the address conversion unit 31 and written to the output buffer 28. However, if no address translation is required, the received ATM cell header is written to the output buffer 28. Next, 48 bytes of the ATM cell payload portion are read from the input buffer 24 and written to the output buffer 28.

On the other hand, in the case of AAL2, the STF and CPS-Packet Header are read from the input buffer 24, the new VPI / VCI and HEC are generated by referring to the address conversion unit 31 according to the VPI / VCI / CID, and then the cell storage unit ( 32), and reads the CPS-packet payload portion from the input buffer 24 according to OSF and LI (Length Indicator, length indicator, 6 bits), that is, converts it into an AAL5 cell and writes it to the cell storage unit 32. do.

Thereafter, when a 53-byte ATM cell is configured, the cell storage unit 32 reads the stored AAL5 cell and writes it to the output buffer 28. If the 53-byte ATM cell is not configured and the timer is not terminated, the ATM cell is received. If the 53-byte ATM cell is not configured and the timer expires, zero pad and CPSC-PDU trailer (i.e., Common Part Convergence Sublayer User-to-User Indication (CPCS-UU), 8-bit), Common Part Indicator (CPI), Length (Length Field, 16-bit), CRC Generates -32 (Cyclic Redundancy Check, 32 bits) to write to the output buffer 28 or the feedback output buffer 29 according to the selection of the demultiplexer 27.

The Utopia output matching unit 30 performs a master or slaver function of UTOPIA Level 1 or 2, and reads an ATM cell from the output buffer 28 to operate the Utopia Level 1 or 2 Utopia bus. 210) to transmit an ATM cell.

The central processing unit 3, which is an external device, knows the state of the AAL2,5 converter 2 by reading the information from the state and control storage unit 33 via the path 215 and the central processing unit matching unit 34. It is also possible to control the operation mode of the AAL2,5 converter 2 by recording the information in the state and control storage 33.

The central processing unit 3 sends the mode of operation of the utopia input matching unit 23 and the utopia output matching unit 30 to the state and control storage unit 33 via the path 215 and the central processing unit matching unit 34. By setting, the utopia input matching section 23 and the utopia output matching section 30 function as a master or a slaver of the UTOPIA Level 1 or 2.

In addition, by setting the operation modes of the multiplexer 25 and the demultiplexer 27, the normal mode or the loopback mode operation of the AAL2, 5 converter 2 is controlled. The normal mode of the AAL2,5 converter 2 represents an operation mode constituting the path 201 → 202 → 203 → 205 → 206 → 207 → 209 → 210, and the feedback mode indicates the path (201 → 202 → 203 → 205 → 206 → 208 → 104 → 105 → 106 → 107 → 109 → 110. The feedback mode of the AAL2,5 converter 2 is based on the base station, control station, core network test and between the base station and the control station of the next generation mobile communication system using the AAL2 / AAL5 interconversion device of FIG. Used for matching tests.

Further, it is possible to set whether or not address conversion is required when converting from AAL5 (control) to AAL5 (control) in the AAL2 and 5 converters 26, and a timer end time when converting from AAL2 to AAL5.

In addition, the AAL2,5 converter 2 stores the HEC of the ATM cell header portion in the AAL2,5 converter 26 and stores the VPI / VCI in the state and control storage 33 in case of an error. Can be notified to the central processing unit 3 as an external device.

The central processing unit 3 controls the VPI / VCI address conversion by recording the information in the address conversion unit 31 via the path 216.

3 is a flowchart illustrating an operation of the AAL5,2 converter of FIG. 2 according to the present invention.

As shown in FIG. 3, when the AAL5,2 converter 14 confirms receipt of an ATM cell from the input buffer 12 or the feedback output buffer 29 (301), the input buffer 12 or the feedback output buffer. In step 29, 5 bytes of the ATM cell header portion are read (302), and the HEC of the ATM cell header portion is checked (303).

If there is an error as a result of the check, 48 bytes of the ATM cell payload are read from the input buffer 12 to invalidate the ATM cell (304).

As a result of the check, if there is no error, the ATM cell identifies AAL5 (traffic) or AAL5 (control) by checking the VPI or VCI of the ATM cell header portion (305).

As a result of the check, in the case of AAL5 (control), if address translation is requested (306), the new VPI / VCI and HEC are generated with reference to the address translator 19 and written to the output buffer 16 (307). However, if no address translation is required (306), the received ATM cell header is written to the output buffer 16 (308).

Thereafter, 48 bytes of the ATM cell payload portion are read from the input buffer 12 (309) and written to the output buffer 16 (310).

As a result of the check, in the case of AAL5 (traffic), the new VPI / VCI and HEC are generated and written to the cell storage unit 20 by referring to the address conversion unit 19 according to the VPI / VCI (311). Next, 48 bytes of the ATM cell payload portion are read from the input buffer 12 (312), and STF (OSF, SN, P) and CPS packet headers (CID, LI, UUI, HEC) and CPS according to the AAL2 standard. A packet payload (CPS-INFO) is generated, that is, converted into an AAL2 cell composed of CPS-packets multiplexed in one ATM cell and recorded in the cell storage unit 20 (313).

Next, when a 53-byte ATM cell is configured (314), the cell storage unit 20 reads the stored AAL2 cell and writes it to the output buffer 16 (315). However, if the 53-byte ATM cell is not configured (314) and the timer has not expired (316), then the transition to the ATM cell reception processing state, " 301 " On the other hand, if the 53-byte ATM cell is not configured (314) and the timer expires (316), zero pad is added to the output buffer 16 or feedback output buffer 17 depending on the selection of the demultiplexer 15. (317).

4 is a flowchart illustrating an operation of the AAL2,5 converter of FIG. 2 according to the present invention.

As shown in FIG. 4, when the AAL2,5 converter 26 confirms receipt of an ATM cell from the input buffer 24 or the feedback output buffer 17 (401), the input buffer 24 or the feedback output buffer. In step 17, 5 bytes of the ATM cell header portion are read (402), and the HEC of the ATM cell header portion is checked (403).

As a result of the check, if there is an error, 48 bytes of the ATM cell payload are read to invalidate the ATM cell (404).

If there is no error as a result of the check, it is determined whether the ATM cell is AAL2 or AAL5 (control) by checking the VPI or VCI of the ATM cell header portion (405).

As a result of the check, in the case of AAL5 (control), if address translation is required (406), a new VPI / VCI and HEC are generated with reference to the address translator 31 and written to the output buffer 28 (407). However, if no address translation is required (406), the received ATM cell header is written to the output buffer 28 (408).

Thereafter, 48 bytes of the ATM cell payload portion are read from the input buffer 24 (409) and written to the output buffer 28 (410).

As a result, in the case of AAL2, the STF and CPS-Packet Header are read from the input buffer 24, and the new VPI / VCI and HEC are generated by referring to the address conversion unit 31 according to the VPI / VCI / CID. In step 411, the CPS-packet payload portion is read from the input buffer 24 in accordance with OSF and LI (412), that is, converted into an AAL5 cell and recorded in the cell storage unit 32 (413). .

Next, when the 53-byte ATM cell is configured (414), the cell storage unit 32 reads the stored AAL5 cell and writes it to the output buffer 28 (415). However, if the 53-byte ATM cell is not configured (414) and the timer has not expired (416), the process transitions to the ATM cell reception processing state, " 401 " On the other hand, when the 53-byte ATM cell is not configured (404) and the timer expires (416), a zero pad and a CPSC-PDU trailer (CPCS-UU, CPI, Length, CRC-32) are generated. According to the selection of the demultiplexer 27, the data is written to the output buffer 28 or the feedback output buffer 29 (417).

Fig. 5 shows the AAL5 and AAL2 protocol formats used in the present invention, in which the " dashed arrow " shows an example of conversion from AAL5 to AAL2 of the AAL5,2 converter 1, and " solid arrow " The example of conversion from AAL2 to AAL5 of the apparatus 2 is shown.

6 shows an example of applying the cell conversion apparatus according to the present invention to the next generation mobile communication system, and by using the AAL2 / AAL5 mutual conversion device, each subsystem in the base station, the control station, and the core network performs only AAL5 type communication. It can be seen that each subsystem within the base station, within the control station, and within the core network is simplified.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention is used in a base station, a control station and a core network to convert an AAL2 form into an AAL5 form, and convert the AAL5 form into an AAL2 form to communicate a packet having a small size such as voice traffic of a mobile communication to an ATM cell. It maintains the advantages of AAL2 type which increases the bandwidth and trunk efficiency. In addition, each subsystem between the base station and the control station performs only AAL5 type communication so that the base station and the control station The effect is to simplify the hardware of each subsystem inside and inside the core network.

Claims (17)

In the apparatus for converting the AAL (ATM Adaptation Layer) type asynchronous transfer mode (ATM) cell, Control means for generating state and control information necessary for converting an AAL5 type ATM cell into an AAL2 type ATM cell and state and control information required for converting an AAL2 type ATM cell to an AAL5 type ATM cell; First AAL5,2 converting means for verifying a header of the ATM cell and converting an AAL5 type traffic ATM cell to be AAL2 type ATM cell based on address translation control information under the control of the control means; And Under the control of the control means, first AAL2,5 conversion means for converting an AAL2 type ATM cell to be converted into an AAL5 type traffic ATM cell based on the address translation control information by checking the header of the ATM cell. Cell conversion apparatus in a wireless communication system comprising a. The method of claim 1, The first AAL5, second conversion means, Utopia input matching means for receiving an ATM cell via a utopia bus; First storage means for storing at least one ATM cell received in the utopia input matching means; Multiplexing means for selectively outputting either output data of the first storage means or output data of the feedback output buffer of the first AAL2,5 conversion means; Second storage means for storing address translation control information; Third storage means for storing state and control information necessary for converting an AAL5 type ATM cell into an AAL2 type ATM cell; According to the state and control information, the header of the ATM cell selected and outputted by the multiplexing means is checked to determine whether to convert or bypass the type of the AAL5 type based on the address translation control information. Second AAL5,2 conversion means for converting the traffic ATM cell into an AAL2 type ATM cell and bypassing the control ATM cell; Cell storing means for storing the type-converted AAL2 type ATM cell; And Output means for outputting at least one AAL2 type ATM cell converted by the second AAL5,2 conversion means according to an operation mode (normal mode or feedback mode) Cell conversion apparatus in a wireless communication system comprising a. The method according to claim 1 or 2, The first AAL2,5 conversion means, Utopia input matching means for receiving an ATM cell via a utopia bus; First storage means for storing at least one ATM cell received in the utopia input matching means; Multiplexing means for selectively outputting either output data of the first storage means or output data of the feedback output buffer of the first AAL5, 2 conversion means; Second storage means for storing address translation control information; Third storage means for storing state and control information necessary for converting an AAL2 type ATM cell into an AAL5 type ATM cell; According to the state and control information, the header of the ATM cell selected and outputted by the multiplexing means is determined to determine whether to convert or bypass the type of the AAL2 type, based on the address translation control information. Second AAL2,5 converting means for converting the ATM cell into an AAL5 type traffic ATM cell and bypassing the control ATM cell; Cell storage means for storing the type AAL5 type traffic ATM cell; And Output means for outputting at least one AAL5 type traffic ATM cell converted by the second AAL2,5 conversion means according to an operation mode (normal mode or feedback mode) Cell conversion apparatus in a wireless communication system comprising a. The method of claim 3, wherein The first AAL5,2 converting means and the first AAL2,5 converting means, In the construction of the next generation mobile communication system, each subsystem in the base station, the control station, and the core network only performs AAL5 type communication, thereby simplifying the hardware of each subsystem in the base station, the control station, and the core network. And a cell conversion device in a wireless communication system. The method of claim 3, wherein The first AAL5,2 converting means and the first AAL2,5 converting means, Used in base station, control station and core network of next generation mobile communication system, wireless communication system which increases transmission width and trunk efficiency by converting packet having small size such as voice traffic of mobile communication into AAL2 type ATM cell Cell conversion device in. In the apparatus for converting the AAL (ATM Adaptation Layer) type asynchronous transfer mode (ATM) cell, Utopia input matching means for receiving an ATM cell via a utopia bus; First storage means for storing at least one ATM cell received in the utopia input matching means; Multiplexing means for selectively outputting one of the output data of the first storage means or the output data of the feedback output buffer of an apparatus (AAL2, 5 conversion apparatus) for converting an AAL2 type ATM cell into an AAL5 type ATM cell; Second storage means for storing address translation control information; Third storage means for storing state and control information necessary for converting an AAL5 type ATM cell into an AAL2 type ATM cell; According to the state and control information, the header of the ATM cell selected and outputted by the multiplexing means is checked to determine whether to convert or bypass the type of the AAL5 type based on the address translation control information. AAL5,2 converting means for converting the traffic ATM cell into an AAL2 type ATM cell and bypassing the control ATM cell; Cell storing means for storing the type-converted AAL2 type ATM cell; And Output means for outputting at least one AAL2 type ATM cell converted by the AAL5,2 conversion means according to an operation mode (normal mode or feedback mode) Cell conversion apparatus in a wireless communication system comprising a. The method of claim 6, The AAL5,2 conversion means for converting an AAL5 type ATM cell into an AAL2 type ATM cell, Upon receipt of an ATM cell from the first storage means or the feedback output buffer, 5 bytes of an ATM cell header portion are read from the first storage means or the feedback output buffer, and header error control (HEC) of the ATM cell header is read. A first step of inspecting the portion; A second step of invalidating the ATM cell by reading 48 bytes of the ATM cell payload if there is an error in the HEC check as a result of the check in the first step; If there is no error in the HEC check, the virtual path identifier (VPI) or the virtual channel identifier (VCI) of the ATM cell header part is determined whether the ATM cell is AAL5 (traffic) or AAL5 (control). Third step to confirm through; As a result of the checking in the third step, in the case of AAL5 (control), when address translation is required, a new VPI / VCI and HEC are generated and written to the output means with reference to the second storage means, and address translation is not required. If fourth, writing the received ATM cell header to the output means; A fifth step of reading the 48 bytes of the ATM cell payload portion from the first storage means and writing it to the output means after performing the fourth step; A sixth step of generating new VPI / VCI and HEC with reference to the second storage means according to VPI / VCI and recording the same in the cell storage means in the case of AAL5 (traffic); After performing the sixth step, the first storage means reads 48 bytes of the ATM cell payload portion, generates a start field (STF), a CPS packet header and a CPS packet payload according to the AAL2 standard. A seventh step of writing to the cell storing means; An eighth step of reading the AAL2 cell configured in the cell storage means and writing it to the output means when a 53-byte ATM cell is configured after performing the seventh step; And After performing the seventh step, if the 53-byte ATM cell is not configured and the timer has not expired, the process proceeds to the processing step after receiving the ATM cell of the first step, and the 53-byte ATM cell is not configured and the timer is terminated. The ninth step of writing to the output means according to the selection of the demultiplexer by adding zero; Cell conversion apparatus in a wireless communication system comprising a. The method of claim 7, wherein The output means, A demultiplexer for selectively outputting an AAL2 type ATM cell converted by the AAL5,2 converting means into one of an output buffer and a feedback output buffer according to an operation mode; An output buffer for temporarily storing the AAL2 type ATM cell selectively output by the demultiplexer in the normal mode; A utopia output matching unit for transmitting an AAL2 type ATM cell stored in the output buffer through a utopia bus; And Feedback output buffer for temporarily storing AAL2 type ATM cells selectively output by the demultiplexer in feedback mode Cell conversion apparatus in a wireless communication system comprising a. In the apparatus for converting the AAL (ATM Adaptation Layer) type asynchronous transfer mode (ATM) cell, Utopia input matching means for receiving an ATM cell via a utopia bus; First storage means for storing at least one ATM cell received in the utopia input matching means; Multiplexing means for selectively outputting one of the output data of the first storage means or the output data of the feedback output buffer of an apparatus (AAL5, 2 conversion apparatus) for converting an AAL5 type ATM cell into an AAL2 type ATM cell; Second storage means for storing address translation control information; Third storage means for storing state and control information necessary for converting an AAL2 type ATM cell into an AAL5 type ATM cell; According to the state and control information, the header of the ATM cell selected and outputted by the multiplexing means is determined to determine whether to convert or bypass the type of the AAL2 type, based on the address translation control information. AAL2,5 conversion means for converting an ATM cell into an AAL5 type traffic ATM cell, and bypassing the control ATM cell; Cell storage means for storing the type AAL5 type traffic ATM cell; And Output means for outputting at least one AAL5-type traffic ATM cell converted by the AAL2,5 conversion means according to an operation mode (normal mode or feedback mode) Cell conversion apparatus in a wireless communication system comprising a. The method of claim 9, The AAL2,5 conversion means for converting an AAL2 type ATM cell into an AAL5 type ATM cell, Upon receipt of an ATM cell from the first storage means or the feedback output buffer, 5 bytes of an ATM cell header portion are read from the first storage means or the feedback output buffer, and header error control (HEC) of the ATM cell header is read. A first step of inspecting the portion; A second step of invalidating the ATM cell by reading 48 bytes of the ATM cell payload if there is an error in the HEC check as a result of the check in the first step; When there is no error in the HEC check as a result of the first step, whether the ATM cell is AAL2 or AAL5 (control) is checked through the virtual path identifier (VPI) or the virtual channel identifier (VCI) of the ATM cell header part. Third step; As a result of the checking in the third step, in the case of AAL5 (control), when address translation is required, a new VPI / VCI and HEC are generated and written to the output means with reference to the second storage means, and address translation is not required. If fourth, writing the received ATM cell header to the output means; A fifth step of reading the 48 bytes of the ATM cell payload portion from the first storage means and writing it to the output means after performing the fourth step; As a result of the checking in the third step, in the case of AAL2, the first storage means reads a start field (STF) and a CPS (Common Part Sublayer) packet header, and stores the second according to the VPI / VCI / channel identifier (CID). A sixth step of generating new VPI / VCI and HEC with reference to the means and writing to the cell storing means; After performing the sixth step, a seventh step of reading the CPS packet payload portion from the first storage means according to the offset field OSF and the length indicator LI and writing it to the cell storage means; An eighth step of reading the AAL5 cell configured in the cell storage means and writing it to the output means when a 53-byte ATM cell is configured after performing the seventh step; And After performing the seventh step, when the 53-byte ATM cell is not configured and the timer is not terminated, the process proceeds to the processing step after receiving the ATM cell of the first step, and the 53-byte ATM cell is not configured and the timer is terminated. The ninth step of generating zero and adding CPSC-PDU trailer to the output means according to the selection of the demultiplexer. Cell conversion apparatus in a wireless communication system comprising a. The method of claim 10, The output means, A demultiplexer for selectively outputting an AAL5 type ATM cell converted by the AAL2,5 conversion means into one of an output buffer and a feedback output buffer; An output buffer for temporarily storing an AAL5 type ATM cell selectively output by the demultiplexer in a normal mode; A utopia output matching unit for transmitting an AAL5 type ATM cell stored in the output buffer through a utopia bus; And Feedback output buffer for temporarily storing AAL5 type ATM cells selectively outputted by the demultiplexer in feedback mode Cell conversion apparatus in a wireless communication system comprising a. The method according to any one of claims 6 to 11, The utopia input matching means, It functions as a master or slaver of UTOPIA level 1 or 2, receives ATM cells through a utopia bus operating at utopia level 1 or 2, and transmits the ATM cell to the first storage means through an internal path. Record the ATM cell, The utopia output matching unit, It functions as a master or slaver at UTOPIA level 1 or 2, and reads an ATM cell from the output buffer and transmits the ATM cell to a utopia bus operating at utopia level 1 or 2. A cell conversion device in a wireless communication system. The method according to claim 6 or 9, The third storage means, The central processing unit, which is an external device, reads the information through the central processing unit matching unit so that the state of the AAL5, 2 conversion device or the AAL2, 5 conversion device can be known, and the information is recorded under the control of the central processing device. And a control mode of the AAL 5, 2 converter or the AAL 2, 5 converter. The method according to claim 6 or 9, The third storage means, Storing the operation modes of the utopia input matching unit and the utopia output matching unit, and controlling the normal mode or feedback mode operation of the AAL5,2 converter or the AAL2,5 converter; It stores the operation mode and controls the AAL5,2 converter or feedback mode of the AAL2,5 converter to be used for the base station, the control station, the core network internal test, and the matching test between the base station and the control station, the control station and the core network. A cell conversion device in a wireless communication system, characterized in that it stores a signal. The method according to claim 6 or 9, The third storage means, Signal for setting whether address conversion is required when converting from AAL5 (control) to AAL5 (control) in the AAL5,2 converting means or converting from AAL5 (control) to AAL5 (control) in the AAL2,5 converting means. And a signal for setting a timer end time when converting from AAL5 (traffic) to AAL2 or converting from AAL2 to AAL5 (traffic), and the HEC of the ATM cell header portion of the AAL5,2 converting means or AAL2,5 converting means. And storing the VPI / VCI when there is an error, and storing a signal for notifying the central processing unit, which is an external device, of the state of the AAL5,2 conversion device or the AAL2,5 conversion device. Cell conversion apparatus in a communication system. In the method of converting an AAL (ATM Adaptation Layer) type asynchronous transfer mode (ATM) cell, A first step of receiving an ATM cell via a utopia bus; A second step of selecting one of feedback output data of a device (AAL2, 5 conversion device) for converting a receiving ATM cell or an AAL2 type ATM cell into an AAL5 type ATM cell; Based on the state and control information required for converting the ATM cell to the AAL2 type ATM cell, the header of the ATM cell selected in the second step is checked to determine whether to convert or bypass the ATM cell, and then, based on the address translation control information. Converting the AAL5 type traffic ATM cell to AAL2 type ATM cell and bypassing the control ATM cell; A fourth step of outputting the type-converted AAL2 type ATM cell according to an operation mode (normal mode or feedback mode) Cell conversion method in a wireless communication system comprising a. In the method of converting an AAL (ATM Adaptation Layer) type asynchronous transfer mode (ATM) cell, A first step of receiving an ATM cell via a utopia bus; A second step of selecting one of feedback output data of an apparatus (AAL5, 2 conversion apparatus) for converting a receiving ATM cell or an AAL5 type ATM cell into an AAL2 type ATM cell; According to the state and control information necessary to convert the AAL5 type ATM cell into the AAL2 type ATM cell, the header of the ATM cell selected in the second step is checked to determine whether to convert or type the address, and to control address translation. Converting the AAL5 type traffic ATM cell to be type-converted based on the information into an AAL2 type ATM cell, and bypassing the control ATM cell; And A fourth step of outputting the type-converted AAL2 type ATM cell according to an operation mode (normal mode or feedback mode) Cell conversion method in a wireless communication system comprising a.