KR100310865B1 - Apparatus and method for interworking pstn and atm network to accommodate telephone service in atm - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a transmission and reception matching device for accommodating telephone service in an asynchronous transmission mode, a method and a computer readable recording medium having recorded thereon a program for realizing the method.

2. The technical problem to be solved by the invention

The present invention converts telephone data having a constant channel and frame into compressed data of variable size in units of frames and converts it into data of an adaptive layer 2 (AAL2) format in an asynchronous transmission mode. To provide a transmission and reception matching device for accommodating telephone service in an asynchronous transmission mode for restoring telephone data of a computer, and a method and a computer-readable recording medium having recorded thereon a program for realizing the method.

3. Summary of Solution to Invention

The present invention includes a first step of receiving telephone data signals from a plurality of telephone data transmission paths and compressing the telephone data signals in units of frames; A second step of multiplexing a plurality of data compressed within a predetermined time interval into data in an ATM adaptation layer 2 (AAL2) format; A third step of converting data of the ATM adaptation layer 2 (AAL2) format into an ATM cell; And converting the ATM cell into a signal for transmission through an ATM transmission path.

4. Important uses of the invention

The present invention is used in a communication system.

Description

Transmission and reception matching device and method for accommodating telephone service in asynchronous transmission mode {APPARATUS AND METHOD FOR INTERWORKING PSTN AND ATM NETWORK TO ACCOMMODATE TELEPHONE SERVICE IN ATM}

The present invention relates to a transmission and reception matching device for accommodating telephone service in an asynchronous transmission mode, a method and a computer readable recording medium recording a program for realizing the method, in particular an Asynchronous Transfer Mode (ATM). When using the network as a telephone network relay, the signal from the Public Switched Telephone Network (PSTN) switch is converted to the signal used in the ATM network to accommodate the existing telephone service. A transmission and reception matching device for accommodating telephone service in an asynchronous transmission mode for converting a signal to a telephone network, and a method thereof and a computer-readable recording medium having recorded thereon a program for realizing the method.

In order to accommodate multimedia services such as the Internet, which is rapidly increasing in the telephone network, high-speed and broadband channels are required by its basic characteristics. In the existing PSTN network, 64,000 bits per second (bps) of transmission bandwidth is provided. It was unsuitable to accept it.

Accordingly, ATMs have emerged as a necessity for establishing a broadband transmission network in order to provide multimedia services and to handle rapidly increasing data traffic.

The ATM network can transmit data to a cell having a fixed size of 53 bytes, thereby flexibly using the resources of the network, and guaranteeing the Quality of Services (QoS) of data transmission despite being a data network. As a result, it will be attracting attention as the next generation network and will be built as a primary backbone network.

Recently, standardization efforts and researches to accommodate the telephone service provided by the existing PSTN network in ATM networks have been carried out by standardization organizations such as the Telecommunication part of International Telecommunication Union (ITU-T) and ATM Forum. Products based on these standards are already on the market.

The ATM Forum has led the work of the Voice and Telephony Over ATM (VTOA) Work Group (WTO) to accommodate voice-quality services in ATM networks. It analyzes the circuit emulation service to deliver to the ATM network and narrowband signal information when a call occurs and routes the 64kbps channel to the interworking incoming interworking device (IWF), and the narrowband signal itself is connected to a separate ATM virtual channel. A switched trunking scheme that transparently transfers between IWFs through (VCC: Virtual Channel Connection) is proposed.

The Circuit Emulation Service (CES) specification using ATM Adaptation Layer 1 (AAL1), the first standardized in the ATM Forum, is based on the asynchronous digital layer (PDH: DS1 / E1 / J2, DS3 / E3). Plesiochronous Digital Hierarchy) is a method of point-to-point interconnection over ATM networks.

Although the circuit emulation service (CES) method is actually easy to apply or implement, the emulated T1 / E1 line is connected to a point-to-point ATM Permanent Virtual Circuit (PVC), rather than the existing time division multiplexing ( There is a problem that more bandwidth is required than TDM: Time-Division Multiplexing, and it is not possible to reduce technologies such as voice compression or silence cancellation, thereby reducing the cost of voice calls.

The proposed method to increase the bandwidth efficiency is a switched trunking method using ATM Adaptation Layer 2 (AAL2).

This method allocates bandwidth as needed by routing 64kbps channel based on call from IWF, which is a matching device of PSTN and ATM network, and can use bandwidth more efficiently.It is possible to use compression, silence elimination and idle channel elimination. Network resources can be used more efficiently.

However, this scheme is more efficient in bandwidth than circuit emulation, but additional signaling between two IWFs is required for demultiplexing by multiplexing the voice frames arriving through one transmission channel by channel in the frame. The implementation was complicated because additional features had to be added. In addition, by processing a call for each channel, one telephone line waits to fill an idle space of an ATM cell, or only partially fills and sends the rest without using, so that there is a problem of compromise in terms of cell transmission delay and bandwidth efficiency. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and converts telephone data having a constant channel and frame into compressed data of variable size in units of frames, thereby converting data of an adaptive layer 2 (AAL2) format in an asynchronous transmission mode. A transmission and reception matching device for accommodating a telephone service in an asynchronous transmission mode in which the received signal is received and restored to the original telephone data, and a computer-readable recording recording the method and a program for realizing the method. The purpose is to provide a medium.

1 is an exemplary configuration diagram of a communication network to which the present invention is applied.

2 is a block diagram of a transmission matching device for accommodating a telephone service in an asynchronous transmission mode according to the present invention.

3 is a flowchart illustrating a transmission matching method for accepting a telephone service in an asynchronous transmission mode according to the present invention.

4 is an exemplary view illustrating transmission of compressed E1 data using an ATM cell according to the present invention.

5 is an exemplary view illustrating a process of multiplexing compressed E1 frame data into an ATM cell according to the present invention.

6 is a block diagram of an embodiment of a reception matching device for accommodating a telephone service in an asynchronous transmission mode according to the present invention.

7 is a flowchart illustrating a reception matching method for accepting a telephone service in an asynchronous transmission mode according to the present invention.

* Explanation of symbols for the main parts of the drawings

21: E1 compression unit 22: AAL2 multiplexer

23: ATM cell conversion unit 24: DS-n / STM-n conversion unit

An apparatus of the present invention for achieving the above object is a transmission and reception matching device for accommodating telephone service in an Asynchronous Transfer Mode (ATM), receiving a telephone data signal from the telephone data transmission channel in real time compression by frame unit ATM signaling means for multiplexing the data into an ATM Adaptation Layer-2 (AAL2) format, forming an ATM cell, and transmitting the data to an ATM network; And telephone signaling means for extracting the AAL2 format data from the signal transmitted through the ATM network, restoring frame-by-frame compression, reproducing the telephone data signal, and transmitting the telephone data signal to the telephone data transmission line. It is done.

In addition, another apparatus of the present invention is a transmission matching device for accommodating telephone service in an asynchronous transfer mode (ATM), wherein each telephone data signal is received from a telephone data transmission path and the telephone data signal is received in units of frames. A plurality of telephone data compressing means for compressing the data into; Multiplexing means for multiplexing compressed data from the plurality of telephone data compression means into data in an ATM Adaptation Layer-2 (AAL2) format; First converting means for converting the AAL2 format data from the multiplexing means into an ATM cell; And second conversion means for converting the ATM cell from the first conversion means into a signal for transmission through the ATM transmission path.

In still another aspect of the present invention, there is provided a reception matching device for receiving an ATM network signal and converting it into a telephone network signal for accommodating telephone service in an asynchronous transfer mode (ATM). Cell extracting means for extracting an ATM cell from the signal; Analyzing and demultiplexing an ATM Adaptation Layer-2 (AAL2) format data generated by removing a header from the ATM cell from the cell extracting means, and extracting the compressed telephone data signal in units of frames. Demultiplexing means for; And restoring means for receiving the telephone data signal compressed in units of frames from the demultiplexing means and restoring the telephone data signal before compression to transmit the telephone data signal to the telephone data transmission line.

In addition, the method of the present invention, in the transmission and reception matching method for accommodating telephone service in the asynchronous transmission mode applied to the transmission and reception matching device for accommodating telephone service in the asynchronous transmission mode, receiving a telephone data signal from the telephone data transmission path frame A first step of compressing the data into units of an ATM Adaptation Layer-2 (AAL2) format, multiplexing the data into an ATM cell, and transmitting the data to an ATM network; And extracting the AAL2 format data from the signal transmitted through the ATM network, restoring frame-by-frame compression, and reproducing the telephone data signal to be transmitted to the telephone data transmission path. .

In addition, another method of the present invention is a matching method for accommodating telephone service in an asynchronous transmission mode, which is applied to a matching device for accommodating telephone service in an asynchronous transmission mode, and receives telephone data signals from a plurality of telephone data transmission paths. Compressing the telephone data signal in units of frames; A second step of multiplexing a plurality of data compressed within a predetermined time interval into data in an ATM adaptation layer 2 (AAL2) format; A third step of converting data of the ATM adaptation layer 2 (AAL2) format into an ATM cell; And converting the ATM cell into a signal for transmission through an ATM transmission path.

Further, another method of the present invention is a reception matching method for accepting a telephone service in an asynchronous transmission mode applied to a reception matching device for accommodating a telephone service in an asynchronous transmission mode, in which a signal received through the ATM transmission path is used. Extracting an ATM cell; A second step of extracting the telephone data signal compressed in units of frames by analyzing and demultiplexing data of an ATM Adaptation Layer-2 (AAL2) format generated by removing a header from the extracted ATM cell; And a third step of restoring the extracted telephone data signal by the frame unit to the telephone data transmission path before the compression.

The present invention also provides an ATM adaptation layer 2 (AAL2: ATM Adaptation) by receiving a telephone data signal from a telephone data transmission line and compressing it frame by frame to a transmission / reception matching device for accommodating telephone service in an asynchronous transmission mode having a large capacity processor. A first function of multiplexing data in a Layer-2) format and making an ATM cell and transmitting the same to an ATM network; And a second function of extracting the AAL2 format data from the signal transmitted through the ATM network, restoring frame-by-frame compression, and reproducing the telephone data signal to be transmitted to the telephone data transmission path. .

The present invention also provides a first function of receiving telephone data signals from a plurality of telephone data transmission paths and compressing the telephone data signals frame by frame to a matching device for accommodating telephone service in an asynchronous transmission mode having a large capacity processor. ; A second function of multiplexing a plurality of data compressed within a predetermined time interval into data in an ATM adaptation layer 2 (AAL2) format; A third function of converting data of the ATM adaptation layer 2 (AAL2) format into an ATM cell; And a fourth function of converting the ATM cell into a signal for transmission through an ATM transmission path.

The present invention also provides a reception matching device for accommodating telephone service in an asynchronous transmission mode having a large capacity processor, comprising: a first function of extracting an ATM cell from a signal received through the ATM transmission path; A second function of analyzing and demultiplexing data of an ATM Adaptation Layer-2 (AAL2) format generated by removing a header from the extracted ATM cell and extracting the telephone data signal compressed in units of frames; And a third function of reconstructing the extracted telephone data signal by the frame unit and transmitting the telephone data signal before compression to a corresponding telephone data transmission line.

The present invention relates to a transmission method for compressing a signal from a PSTN switch in units of frames and multiplexing according to the AAL2 method to transmit an ATM cell to accommodate an existing telephone service, such as the AAL1 method, when using an ATM network as a relay network of a telephone network. In bar, it is used for efficient interworking with a high speed communication network based on an existing communication network (PSTN / N-ISDN) and ATM.

Here, AAL plays the following role.

The AAL performs the required functions from the user control and management layer or supports the mapping between the ATM layer and the upper layer, and the functions performed in the AAL will depend on the requirements of the upper layer. In short, AAL performs all the functions required to link information between ATM networks and non-ATM applications.

AAL1 used in the conventional conversion of telephone data to ATM data and AAL2 used in the present invention will be described as follows. Here, the telephone data refers to all data transmitted over the telephone line and includes voice data, voice level data, and the like.

As defined in ITU-T Rec. I.363.1, AAL1 supports the following services for AAL users:

-Data units with a constant bit rate are transmitted at the same bit rate.

-Send synchronization information between origin and destination.

Send structure information between origin and destination

-If necessary, indicate lost or damaged information not covered by AAL1.

The information payload of AAL1 is always 47 octets and is the basic structure used in circuit emulation. The additional structure of AAL1 has overhead and reduces the information payload, which is used for structure circuit emulation.

When using AAL1 to implement voice over ATM, AAL1 has the following significant limitations.

Only one AAL user is supported.

To reduce latency, there is a significant increase in bandwidth.

-Bandwidth is always occupied even when there is no traffic

-Voice is always supported in 64K increments.

There is no standardized tool in the AAL1 structure for voice compression, detection and suppression of unused calls, unused channel termination or Common Channel Signaling (CCS).

AAL2 is described as follows.

The basic function of the AAL2 protocol is consistent with AAL1 and improves the services provided by the ATM layer to support the functions required by the higher layer.

AAL2 is significantly above the scope of AAL1 by being defined as a structure that includes features that support higher layer requirements that were not possible or considered in the AAL1 architecture.

AAL2 is provided for efficient bandwidth transmission of variable packets. AAL2 can support both Variable Bit Rate (VBR) and Constant Bit Rate (CBR) in ATM network, and VBR service provides voice compression, unused channel release, It enables statistical multiplexing to detect and suppress unused calls. AAL2's VBR and CBR mean that the managers of the ATM network can generate the profitable part of the traffic by optimizing the network according to the traffic load when designing the ATM network.

As a result, AAL2 offers the following advantages over AAL1:

Increased bandwidth efficiency

-Voice compression and silence suppression support

-Unused voice channel support

Multiple user channels with variable bandwidth on a single ATM connection

-VBR ATM traffic class support

In the present invention, by converting telephone data into ATM data using such AAL2, telephone data can be accommodated in an ATM network.

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. In this embodiment, the telephone line for the telephone service is referred to as an E1 transmission line.

1 is an exemplary configuration diagram of a communication network to which the present invention is applied.

The communication network consists of the PSTN exchangers 11 and 19, the E1 transmission paths 12 and 18, the IWFs 13 and 17, the ATM transmission paths 14 and 16, and the ATM network 15.

As shown in the figure, the E1 signal transmitted from the PSTN switch 11 in the network configuration to which the present invention is applied is transmitted to the IWF 13 through the E1 transmission line 12. Here, the IWF is a device having a function of matching the PSTN and the ATM network. Generally, the IWF transmits and receives data and signal messages with the existing PSTN, and transmits and receives data and signals with the ATM network. It consists of parts which match. The E1 signal is converted into a signal form suitable for the ATM network 15 through the IWF 13, and the converted signal is transmitted to the IWF 17 connected to the destination PSTN exchange 19 via the ATM transmission line 14. The ATM transmission paths 14 and 16 are made of PVC so that the ATM network 5 does not require call setup and routing procedures, and can transparently transmit signals from the PSTN exchange 11 to the other PSTN exchanges 19. have.

2 is a block diagram of an embodiment of a transmission matching device for accommodating a telephone service in an asynchronous transmission mode according to the present invention.

In FIG. 2, an apparatus for accommodating a real-time telephone service network in an AAL2 based ATM network is shown in functional blocks.

As shown in the figure, the configuration of the present invention includes a plurality of E1 compression units 21 for generating variable data smaller than 32 octets as a basic size by compressing in real time losslessly for one E1 frame received from the PSTN; For compressed variable data from a plurality of E1 compression units 21, the data from the E1 channel is classified by channel identifier (CID), and AAL2 every 125 microseconds, which is an E1 frame transmission period. ATM cells in which AAL2 multiplexer 22 multiplexes the common part sublayer-protocol data unit (CPS-PDU) and AAL2 CPS-PDUs generated by the AAL2 multiplexer 22 sequentially. ATM cell conversion unit 23 to fill the remaining space after the storage in the pad (PAD) to form an ATM cell, and asynchronous to transfer the ATM cell from the ATM cell conversion unit 23 through the ATM transmission line 14 Transmission rank-n (DS-n: And a DS-n / STM-n converter 24 for converting into a Digital Signal-n) or a Synchronous Transfer Mode-n (STM-n) signal.

The E1 compression unit 21 receiving the E1 signal from the E1 transmission path 12 of the PSTN compresses the E1 signal in units of frames, and transmits the compressed data to the AAL2 multiplexer 22. The E1 compression unit 11 guarantees losslessness and real-time at the same time, and uses 64 kbps pulse code modulation (PCM) in the E1 transmission line by using an algorithm capable of compressing both voice, signaling signals, and voice data. Instead of extracting data into a channel and compressing it in 32-octet E1 frame units, voice, signaling signals, and data are transmitted without distinction.

The E1 signal consists of 16 frames in one multiframe, one frame consists of 32 channels, and one channel has an 8-bit value sampled every 125 ms. That is, in one frame of 32 octets, one octet is one channel.

The compression frame unit of the E1 compression section 21 is 125 ms, and one frame of the E1 signal is read and compressed every 125 ms. In addition, since the plurality of E1 compression units 21 receive the E1 signal from each of the E1 transmission paths and compress the E1 signal, the E1 compression units 21 have a short transmission delay. As a result, the VTOA method, which performs compression and multiplexing for each channel in units of several microseconds, has real time.

The AAL2 multiplexer 22 maps the compressed data received from the plurality of E1 compressors 21 to the AAL2 CPS packet together with the AAL2 Common Part Sublayer (CPS) header within 125 ms.

The AAL2 CPS packets generated as described above are converted into CPS-PDUs and transferred to the ATM cell converter 13. Here, the CPS packet consists of a 3 octet header and a maximum of 45 octet payload, and the CPS-PDU consists of a start field of 1 octet and a payload of 47 octets. The payload of the PDU can carry one or more CPS packets and the unused payload is filled with zeros.

The ATM cell converter 23 adds a 5-octet ATM cell header to the 48-octet AAL2 CPS-PDU received from the AAL2 multiplexer 22 to create an ATM cell, and then the DS-n / STM-n converter 24 To pass).

DS-n / STM-n conversion section 24 is the DS recommended in ITU-T G.804 in case of asynchronous transmission of ATM cells received from ATM cell conversion section 23 to an asynchronous transmission line or a synchronous transmission line. -n Maps to the signal frame, and if synchronous, to the STM-n signal frame recommended in ITU-T G.707.

3 is a flowchart illustrating a transmission matching method for accepting a telephone service in an asynchronous transmission mode according to the present invention.

In the asynchronous transmission mode, the transmission matching method for accommodating telephone service is a method of converting an E1 signal of a telephone network into an ATM signal, and symmetrically receives the ATM signal thus received and restores it to the original E1 signal. There is a way.

Transmission matching method for accepting telephone service in asynchronous transmission mode is as follows. First, the E1 signal received from the E1 transmission line 12 of the PSTN is read by the E1 compression unit 21 in units of frames (301), and the frame is compressed using a real-time lossless compression method (302).

The AAL2 multiplexer 22 receives a plurality of compressed data from several E1 compression units 21 and assembles them into AAL2 CPS-PDUs (303). The ATM cell converter 23 adds an ATM header to make an ATM cell. 304. Then, the plurality of ATM cells are mapped to DS-n or STM-n signal frames by the DS-n / STM-n converter 24 to transmit the existing asynchronous or synchronous transmission lines (305). According to this flow, the telephone network is matched with the ATM network to transmit voice data to the ATM network.

The E1 compression unit 21 receives the E1 signal, which is a telephone network signal, and performs compression, wherein the size of the data varies variably. In addition, the AAL2 multiplexer 22 receives compressed data having a variable size from various E1 compression units 21 to form a CPS-PDU of AAL2. Since the AAL2 multiplexer 22 multiplexes and transmits the compressed signal in the frame unit in the E1 compression unit 21, the AAL2 multiplexer 22 receives and multiplexes the data at a much shorter interval than receiving the compressed signal in the channel unit so that it is closer to real time. Processing becomes possible.

4 is an exemplary view illustrating transmission of compressed E1 data using an ATM cell according to the present invention.

The ATO2 trunking method of the VTOA transmits data according to the packet length, packet time, and sequence interval (recommended in ITU-T I.366.2) determined according to the type of speech coding method for each channel. However, in the transmission method according to the present invention, since E1 frames including a plurality of channels are compressed and transmitted through a lossless real-time compression algorithm, new transmission parameters are defined and used as shown in [Table 1] (ITU-T I). According to the format recommended in 366.2). That is, in the present invention, instead of processing the data for each channel, the data is processed for each frame, and the transmission parameters for the E1 frame compressed and transmitted by the E1 compression unit 21 at this time are shown in [Table 1]. .

UUICodepoint Range Packet length (octets) algorithm M Packet time Sequence interval 0-15 Variable (up to 32) Lossless Real Time Compression Algorithm One 125 125

In the present invention, the packet time is set to 125 ms to transmit the compressed E1 frame, and the sequence interval is also set to 125 ms. That is, data for 125 ms is assumed to be a packet transmission unit, and the packet transmission interval is 125 ms. This is due to the fact that the time length of one frame of the E1 signal is 125 ms and the data is compressed in real time. In addition, the method of extracting the timing clock used to restore the transmitted data increases the user-to-user indication (UUI) codepoint used for sequence numbering every 125 ms. Synchronize the timing clock. The range of UUI codepoints is defined as 0-15 because the UUI codepoints are represented using 4 bits in the CPS packet.

The packet length varies variably up to 32 octets, since one frame of the audio signal is composed of 32 channels, so that even if it is not compressed at all, it cannot exceed the size of 32 octets.

Referring to the above [Table 1] once again as follows.

The range of UUI codepoints is the range of numbers appended to the CPS packet by increasing the number of voice data every 125 ms. The packet length is the length of voice data. The maximum length of one frame is 32 octets ( octet), so no more than 32 octets. The speech data compressed by the E1 compression section 21 are processed according to a real-time lossless compression algorithm.

The transmission unit M is set to one. At this time, the transmission unit (M) indicates how many times the packet length shown in Table 1 is a service data unit (SDU) generated by the compression algorithm. That is, the packet length in Table 1 is equal to M * SDU. Here, the SDU refers to the smallest packet unit processed in the AAL layer, and the generated SDU also differs because the data size is encoded according to an algorithm. M usually uses 1 a lot and some special algorithms use 2,3,4. If M is 1, the packet length in [Table 1] corresponds to the SDU itself.

The time that the data carried in the CPS packet, that is, the packet time according to the packet length, does not exceed 125 ms, and the sequence interval, that is, the interval between packets, does not exceed 125 ms. This is a value required for sequential transmission and real-time transmission by indicating the CPS packet when the AAL2 multiplexer 22 multiplexes the E1 data compressed by each E1 compression unit 21.

4 shows that the completed ATM cell is transmitted with data having an increased UUI codepoint at 125 ms intervals according to this transmission parameter.

5 is a diagram illustrating a process of multiplexing compressed E1 frame data into an ATM cell according to the present invention.

The E1 frame data compressed by the E1 compression unit 21 corresponds to a service data unit (SDU) of the common part sublayer (CPS) of AAL2, and is stored in the CPS-SDU 501. A 3 octet CPS packet header (PH) is added to form a CPS packet 502. In this case, the CPS-SDU 501 corresponds to a payload (PP: Packet Payload) of the CPS packet 502.

The multiplexing function inside the CPS processed by the AAL2 multiplexer 22 merges several types of CPS packets 502 into one ATM connection, that is, as shown in FIG. 5, one or more CPS packets 502 Multiplexed to one CPS-PDU 503.

As a header of the CPS-PDU 502, a start field (SF) of one octet is added to the CPS-PDU payload in which the CPS packets 502 are multiplexed. The start field SF of one octet contains an offset field indicating the start point of the next CPS packet 502 when the CPS packet 502 is divided into two.

The CPS-PDU 503 corresponds to an ATM-SDU, and the ATM cell header of 5 octets is added to the ATM cell 504.

AAL1 supports only a single user on a single ATM connection, but AAL2 can accommodate multiple users with variable bandwidth as shown in FIG. The identification of AAL2 users is made through 8 bits of Channel Identifier (CID), which is one of the fields constituting the CPS packet 502 header, and transmits up to 248 users or E1 in each AAL2 structure. You can recognize the number.

In the present invention, since one frame is transmitted every 125 ms in the E1 transmission line 12, the CPS packets 502 including the E1 frame data compressed within a predetermined time are minimized so that the transmission delay through the ATM cell 504 is minimized. (503) to fill the SDU (48 octets) of the ATM cell. That is, the signals from multiple E1 transmission paths 12 are multiplexed into ATM cells for minimizing transmission delay and filling the data storage space (ATM-SDU) of the ATM cells without empty space.

FIG. 6 is a diagram illustrating a configuration of a reception matching device for accommodating a telephone service in an asynchronous transmission mode according to the present invention.

The transmission matching device described with reference to FIG. 2 converts a signal from a telephone network so that it can be used in an ATM network, and converts the received ATM signal and converts it into a signal from an original telephone network. Reception matching device.

In order for the matching to accommodate telephone service in the asynchronous transmission mode, a transmission matching device and a receiving matching device must be provided. This may be configured as a single transmission / reception matching device. It may be configured as. In this embodiment, separate descriptions are provided through FIGS. 2 and 6.

Referring to FIG. 6, a reception matching device for accommodating a telephone service in an asynchronous transmission mode is as follows.

The reception matching device includes an ATM cell extracting unit 61 for extracting a plurality of ATM cells from a DS-n or STM-n signal, and a plurality of compressed E1 frame data in an ATM cell from the ATM cell extracting unit 61. AAL-2 demultiplexer 62 for extracting AAL-2 CPS-SDU and a plurality of E1 restorers for restoring AAL2 CPS-SDU from AAL2 demultiplexer 62 to the original signal before compression ( 63).

The ATM cell extracting unit 61 extracts 53 bytes of ATM cells from the received DS-n or STM-n signal and delivers the 53-byte ATM cell to the AAL2 demultiplexer 62.

The AAL2 demultiplexer 62 removes the header from the ATM cell received from the ATM cell extracting unit 61, extracts each CPS-SDU by analyzing the packet header of the CPS-PDU, and then restores the corresponding E1 restoring unit. To 63.

The E1 restoring unit 63 restores and reproduces the CPS-SDU data received from the AAL2 demultiplexer 62, that is, the compressed E1 frame data, to the original E1 signal before compression, and then restores the original E1 through the transmission path of the telephone network. Send a signal. One E1 restoring unit 63 exists in accordance with each E1 transmission path of the telephone network.

When a matching device for accommodating telephone service in the asynchronous transmission mode is composed of one, the transmission matching device becomes a transmitting unit and the receiving matching device forms a receiving unit.

7 is a flowchart illustrating a reception matching method for accepting a telephone service in an asynchronous transmission mode according to the present invention.

In the asynchronous transmission mode described in FIG. 3, the transmission matching method for accommodating telephone service converts a signal transmitted from a telephone network into a signal format used in an ATM network. The reception matching method described in FIG. It is used to restore the original signal after converting and transmitting the signal according to the method of Fig. 3.

This may be treated as a matching method for accommodating telephone service in one asynchronous transmission mode as described in FIG. 6 above, or may be treated as a matching method at the transmitting side and the receiving side, respectively.

A reception matching method for accepting a telephone service in an asynchronous transmission mode will be described with reference to FIG. 7.

Receiving the DS-n or STM-n signal transmitted from the ATM cell extracting unit 61 of the reception matching device (701), extracting the ATM cell from the frame of the DS-n or STM-n signal (702), The ATM cell is removed from the AAL2 demultiplexer 62, the packet header of the CPS-PDU is analyzed, and each CPS-SDU is extracted and transmitted to the corresponding E1 restorer 63 (703). Then, the E1 restoring unit 63 restores and reproduces the CPS-SDU data to the original E1 signal before compression (704).

According to this flow, the signal in the ATM network is reproduced as the original signal in the telephone network. This is the reverse of the transmission matching method of converting a signal in a telephone network into a signal in an ATM network, and data compressed in units of frames is restored in units of frames. In addition, the E1 restoring unit 63 processes the data from the plurality of E1 transmission paths through the AAL2 CPS-PDU header information.

In the above-described embodiment, as described above with reference to FIGS. 6 and 7, the matching for accepting the telephone service in the asynchronous transmission mode has been described as being separated from the transmitting side and the receiving side. Since it is possible to do so in one matching device, it may separate transmission and reception as in the embodiment.

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

As described above, the present invention compresses the telephone data transmitted through the telephone data transmission path in a frame unit, multiplexes it according to the AAL2 scheme, turns it into an ATM cell, and transmits the data through the ATM transmission path. The increase in traffic caused by the head can be sufficiently compensated, and each phone data is compressed in real time by frame unit and transmitted along with other compressed signals in AAL2 to save network resources and reduce cell transmission delay. .

Claims (21)

In the transmission and reception matching device for accommodating telephone service in an asynchronous transfer mode (ATM), ATM signaling means for receiving a telephone data signal from a telephone data transmission path and real-time compressing it in units of frames, multiplexing the data in an ATM Adaptation Layer-2 (AAL2) format, making an ATM cell, and transmitting the data to an ATM network; And Telephone signaling means for reproducing the telephone data signal by extracting the data of the AAL2 format from the signal transmitted through the ATM network, restoring the compression in the frame unit, and transmitting the telephone data signal to the telephone data transmission path. Transmission and reception matching device for accommodating telephone service in an asynchronous transmission mode comprising a. The method of claim 1, The ATM signaling means, A plurality of compression means for receiving telephone data signals from telephone data transmission lines of a communication network and compressing the telephone data signals in units of frames; Multiplexing means for multiplexing the compressed data from the plurality of compression means into data of an ATM Adaptation Layer-2 (AAL2) format; First converting means for converting the AAL2 format data from the multiplexing means into an ATM cell; And Second conversion means for converting the ATM cell from the first conversion means into a signal for transmission through an ATM transmission path Transmission and reception matching device for accommodating telephone service in an asynchronous transmission mode comprising a. The method of claim 2, The multiplexing means, Receiving compressed data from the telephone data compression means according to the length of time of the telephone data frame and assembling them into an AAL2 Common Part Sublayer-Protocol Data Unit (CPS-PDU). Transmission and reception matching device for accommodating telephone service in asynchronous transmission mode. The method of claim 3, wherein The multiplexing means, In the asynchronous transmission mode, the compressed data from the telephone data compression means is used as a payload, the CPS packet is formed by including information about the compressed data in a header, and a CPS-PDU is generated from the plurality of CPS packets. Transceiver matching device to accommodate telephone service. The method according to any one of claims 1 to 4, The telephone signal means, Cell extracting means for extracting an ATM cell from a signal received through the ATM transmission path; Analyzing and demultiplexing an ATM Adaptation Layer-2 (AAL2) format data generated by removing a header from the ATM cell from the cell extracting means, and extracting the compressed telephone data signal in units of frames. Demultiplexing means for; And Restoring means for receiving the compressed telephone data signal from the demultiplexing means and restoring it to a telephone data signal before compression and transmitting it to a telephone data transmission line; Transmission and reception matching device for accommodating telephone service in an asynchronous transmission mode comprising a. The method of claim 5, The restoration means, Transmitting and receiving matching device for accommodating telephone service in an asynchronous transmission mode, characterized in that a plurality of recovery means exist for a plurality of transmission paths for the telephone data signal distributed by said demultiplexing means. The method of claim 6, The demultiplexing means, Transmitting and receiving for a telephone service in an asynchronous transmission mode by analyzing the data of the AAL2 format and extracting and transmitting the compressed telephone data signal to the restoration means corresponding to the transmission path of the compressed telephone data signal. Matching device. In a transmission matching device for converting a telephone network signal into an ATM network signal for accommodating telephone service in an asynchronous transfer mode (ATM), A plurality of compression means for receiving telephone data signals from a telephone data transmission path and compressing the telephone data signals in units of frames; Multiplexing means for multiplexing the compressed data from the plurality of compression means into data of an ATM Adaptation Layer-2 (AAL2) format; First converting means for converting the AAL2 format data from the multiplexing means into an ATM cell; And Second conversion means for converting the ATM cell from the first conversion means into a signal for transmission through an ATM transmission path Transmission matching device for accommodating telephone service in an asynchronous transmission mode comprising a. In a reception matching device for receiving an ATM network signal and converting it into a telephone network signal in order to accommodate telephone service in an asynchronous transfer mode (ATM), Cell extracting means for extracting an ATM cell from a signal received through the ATM transmission path; Analyzing and demultiplexing an ATM Adaptation Layer-2 (AAL2) format data generated by removing a header from the ATM cell from the cell extracting means, and extracting the compressed telephone data signal in units of frames. Demultiplexing means for; And Restoring means for receiving the telephone data signal compressed in units of frames from the demultiplexing means and restoring the telephone data signal before compression to transmit the telephone data signal to the telephone data transmission line. Reception matching device for accommodating telephone service in an asynchronous transmission mode comprising a. The method of claim 9, The restoration means, And a plurality of restoring means existing for a plurality of transmission paths for the telephone data signal distributed by the demultiplexing means. In the transmission and reception matching method for receiving telephone service in asynchronous transmission mode applied to the transmission and reception matching device for accommodating telephone service in asynchronous transmission mode, A first step of receiving a telephone data signal from a telephone data transmission path, compressing the data in a frame unit, multiplexing the data in an ATM Adaptation Layer-2 (AAL2) format, forming an ATM cell, and transmitting the data to an ATM network; And A second step of extracting the AAL2 format data from the signal transmitted through the ATM network, restoring frame-by-frame compression, and reproducing the telephone data signal to be transmitted to the telephone data transmission path; Transmission and reception matching method for accommodating telephone service in an asynchronous transmission mode comprising a. The method of claim 11, The first step is, A third step of receiving telephone data signals from a plurality of telephone data transmission lines and compressing the telephone data signals in units of frames; A fourth step of multiplexing the data in the ATM adaptation layer 2 (AAL2) format on the plurality of data compressed within a predetermined time interval; A fifth step of converting data of the ATM adaptation layer 2 (AAL2) format into an ATM cell; And A sixth step of converting the ATM cell into a signal for transmission through an ATM transmission path; Transmission and reception matching method for accommodating telephone service in an asynchronous transmission mode comprising a. The method of claim 12, The third step, A seventh step of receiving respective telephone data signals from a plurality of telephone data transmission paths of a public switched telephone network (PSTN); And An eighth step of compressing the received telephone data signal in units of frames according to a compression scheme that guarantees losslessness and real-time performance; Transmission and reception matching method for accommodating telephone service in an asynchronous transmission mode comprising a. The method of claim 12, The fourth step, A seventh step of mapping the compressed data to an AAL2 CPS packet together with an AAL2 Common Part Sublayer (CPS) header within a range not exceeding a set cell-packet delay; And An eighth step of generating the generated multiple AAL2 CPS packets into one or more common sublayer-protocol data units (CPS-PDUs) Transmission and reception matching method for accommodating telephone service in an asynchronous transmission mode comprising a. The method of claim 14, The CPS packet is, A transmission / reception matching method for accommodating telephone service in an asynchronous transmission mode, characterized in that a packet time and a sequence interval are set to a predetermined time or less for real time transmission. The method according to any one of claims 11 to 15, The second step, Extracting an ATM cell from a signal received through the ATM transmission path; A tenth step of extracting the telephone data signal compressed in units of frames by analyzing and demultiplexing AAL2 format data generated by removing a header from the extracted ATM cell; And An eleventh step of restoring the extracted telephone data signal by the frame unit to the telephone data transmission path before restoring the telephone data signal before compression; Transmission and reception matching method for accommodating telephone service in an asynchronous transmission mode comprising a. A transmission matching method for accommodating telephone service in an asynchronous transmission mode applied to a transmission matching device for accommodating telephone service in an asynchronous transmission mode, Receiving a telephone data signal from a plurality of telephone data transmission paths and compressing the telephone data signal in units of frames; A second step of multiplexing a plurality of data compressed within a predetermined time interval into data in an ATM adaptation layer 2 (AAL2) format; A third step of converting data of the ATM adaptation layer 2 (AAL2) format into an ATM cell; And A fourth step of converting the ATM cell into a signal for transmission through an ATM transmission path Transmission matching method for accommodating telephone service in an asynchronous transmission mode comprising a. A reception matching method for accommodating a telephone service in an asynchronous transmission mode applied to a reception matching device for accommodating a telephone service in an asynchronous transmission mode, Extracting an ATM cell from a signal received through the ATM transmission path; A second step of extracting the telephone data signal compressed in units of frames by analyzing and demultiplexing data of an ATM Adaptation Layer-2 (AAL2) format generated by removing a header from the extracted ATM cell; And A third step of restoring the extracted telephone data signal by the frame unit to the telephone data signal before compression and transmitting it to the corresponding telephone data transmission path; Reception matching method for accommodating telephone service in an asynchronous transmission mode comprising a. In a transmission and reception matching device for accommodating telephone service in an asynchronous transmission mode having a large processor, A first function of receiving a telephone data signal from a telephone data transmission path, compressing the data in a frame unit, multiplexing the data in an ATM Adaptation Layer-2 (AAL2) format, forming an ATM cell, and transmitting the data to an ATM network; And A second function of extracting the AAL2 format data from the signal transmitted through the ATM network, restoring the compression in a frame unit, and reproducing the telephone data signal to be transmitted to the telephone data transmission path; A computer-readable recording medium having recorded thereon a program for realizing this. In a transmission matching device for accommodating telephone service in an asynchronous transmission mode having a large processor, A first function of receiving telephone data signals from a plurality of telephone data transmission lines and compressing the telephone data signals in units of frames; A second function of multiplexing a plurality of data compressed within a predetermined time interval into data in an ATM adaptation layer 2 (AAL2) format; A third function of converting data of the ATM adaptation layer 2 (AAL2) format into an ATM cell; And A fourth function of converting the ATM cell into a signal for transmission through an ATM transmission path A computer-readable recording medium having recorded thereon a program for realizing this. In a reception matching device for accommodating telephone service in an asynchronous transmission mode having a large processor, A first function of extracting an ATM cell from a signal received through the ATM transmission path; A second function of analyzing and demultiplexing data of an ATM Adaptation Layer-2 (AAL2) format generated by removing a header from the extracted ATM cell and extracting the telephone data signal compressed in units of frames; And A third function of restoring the extracted telephone data signal by the frame unit to the telephone data transmission path before restoring the telephone data signal before compression; A computer-readable recording medium having recorded thereon a program for realizing this.