KR100333673B1 - Apparatus for providing voice and telephony service in atm network - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a voice and telephone service providing apparatus in an asynchronous delivery mode network.

2. The problem to be solved by the invention

An object of the present invention is to provide an apparatus for providing voice and telephone level services in an ATM network, as well as various services provided in an ATM network, so that users and network operators can easily accommodate voice services provided in an existing network. .

3. Summary of Solution to Invention

The present invention provides transmission switching means for switching signals of respective channels input from the outside; Transmission processing means for receiving the signals switched through the transmission switching means, generating and multiplexing an ATM cell payload, and transmitting an ATM cell generated by inserting an ATM header into the multiplexed ATM cell payload; And extract the user cell by searching the ATM header of the ATM cell generated by the transmission processing means, and distinguishing the pointer by using the extracted sequence number and the time stamp information of the extracted user cell by searching for the split / assembled header of the extracted user cell. And receiving processing means for delivering the cell by finding the boundary of the frame through the distinguished pointer.

4. Important uses of the invention

The present invention is used in ATM networks.

Description

Apparatus for providing voice and telephone level service in asynchronous delivery mode network {APPARATUS FOR PROVIDING VOICE AND TELEPHONY SERVICE IN ATM NETWORK}

The present invention relates to an apparatus for providing voice and telephone level services in an Asynchronous Transfer Mode (ATM) network, and in particular, provides a voice and telephone level service through an ATM network to connect a public switched telephone network and a narrowband network. The present invention relates to a voice and telephone service providing apparatus.

In general, providing voice and telephony services through an ATM network is referred to as Voice and Telephony Over ATM (VTOA). The standardization organization that is most active in the VTOA-related standardization activities is the ATM Forum.

As such, the VTOA Working Group of the ATM Forum first emulates circuits to provide services for fixed circuits between Private Branch eXchanges (PBXs) in the form of point-to-point. We recommended the Interoperability Specification (CES-IS), and trunked using the AAL1 feature in response to market demand for more diverse capacities, such as supporting multiple end points. Trunking) -VTOA specification is recommended.

In addition, one of the considerations for providing a voice service is the use of ATM network bandwidth. The circuit emulation method for this is a private virtual call (PVC) format regardless of the use of a predetermined channel. As a fixed bandwidth allocation method, the use of the ATM band is inefficient, but the function of the interoperability function (IWF) is simple, mainly for ATM cell matching of fixed channels.

Therefore, as well as various services provided by the ATM network, there is a problem that users and network operators cannot smoothly accommodate the voice service provided by the existing network.

Accordingly, the present invention has been made to solve the above problems, in addition to the various services provided by the ATM network, in the ATM network that allows users and network operators to smoothly accommodate voice services provided by the existing network. It is an object of the present invention to provide a voice and telephone service providing apparatus.

Another object of the present invention is to provide an apparatus for providing voice and telephone service in an ATM network that provides a low cost voice service with a high speed multimedia service to a user.

1 is a block diagram of an embodiment of a voice and telephone service providing apparatus in an asynchronous delivery mode network according to the present invention;

2 is an exemplary configuration diagram for interoperability for interworking with a conventional telephone network in an access network to which the present invention is applied.

3 is a structural diagram of a connection network to which the present invention is applied for interworking with a conventional telephone network.

4 is a diagram illustrating an embodiment of a transmission AAL processing unit of FIG. 1;

5 is a diagram illustrating an embodiment of the transmitting ATM processor of FIG. 1.

6 is a configuration diagram of an embodiment of the transmission connection processing unit of FIG. 1;

7 is a diagram illustrating an embodiment of the reception access processing unit of FIG. 1.

8 is a block diagram of an embodiment of a receiving ATM processor of FIG.

9 is a diagram illustrating an embodiment of the receiving AAL processing unit of FIG. 1;

Explanation of symbols on the main parts of the drawings

110: transmission time slot switching unit 120: transmission AAL processing unit

130: transmission ATM processing unit 140: transmission connection processing unit

150: receiving access processing unit 160: receiving ATM processing unit

170: receiving AAL processing unit 180: receiving time slot switching unit

190: interface processing unit

In order to achieve the above object, the present invention provides an apparatus for providing voice and telephone level services in an Asynchronous Transfer Mode (ATM) network, and includes: a transmission switching for switching signals of respective channels input from the outside; Way; Transmission processing means for receiving the signals switched through the transmission switching means, generating and multiplexing an ATM cell payload, and transmitting an ATM cell generated by inserting an ATM header into the multiplexed ATM cell payload. ; And extracting the user cell by searching the ATM header of the ATM cell generated by the transmission processing means, and extracting the sequence number and the remaining time by searching for the extracted Segmentation And Reassembly (SAR) header. Receiving processing means for distinguishing the pointer by using the stamp information, and finds the boundary of the frame through the distinguished pointer and delivers the cell.

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

1 is a configuration diagram of an apparatus for providing a voice and a telephone level service in an asynchronous delivery mode network according to the present invention, which includes a transmission time slot switching unit 110, a transmission AAL processing unit 120, and a transmission ATM processing unit ( 130, the transmission connection processing unit 140, the reception connection processing unit 150, the reception ATM processing unit 160, the reception AAL processing unit 170, the reception time slot switching unit 180, and the interface processing unit 190 ).

The transmission timeslot switching unit 110 switches 256x256 for 256 channels input through up to eight E1 / DS1 interfaces.

The transmitting AAL processor 120 performs an AAL Type 1 function for each line.

The transmitting ATM processor 130 generates an ATM cell by attaching an ATM header to an ATM payload that is multiplexed and input.

The transmission access processing unit 140 demultiplexes the ATM cells transmitted from the transmission ATM processing unit 130 and then multiplexes again to transfer them to the transmission utopia interface.

The reception access processor 150 demultiplexes an ATM cell transmitted from the reception utopia interface, and then multiplexes the ATM cell to the reception ATM processor 160.

The receiving ATM processor 160 compares and retrieves an ATM header, and transfers the extracted user cell to the receiving AAL processor 170. The extracted operation and maintenance (OAM) cell performs a CRC10 check and stores it.

The receiving AAL processing unit 170 searches for a Segmentation And Reassembly (SAR) header to display a sequence number (SN) and a residual time stamp (RTS) for a synchronous residual time stamp (SRTS). Residual Time Stamp) value extraction and pointer presence.

The reception timeslot switching unit 180 receives the ATM payload from the reception AAL processing unit 170 and records the data in an area allocated for each line to an external static random access memory (SRAM) 128Kx8 101. CDV (Cell Delay Variation) When a certain level is exceeded for buffering, data is read and then switched 256x256 for each data.

The interface processor 190 interconnects the functional units 110, 120, 130, 140, 150, 160, 170, and 180 having the above functions.

FIG. 2 is an exemplary configuration diagram of interoperability for interworking with a conventional telephone network in an access network to which the present invention is applied, including private branch exchange (PBX) 211 and 212, signal processing units 213 and 214, The switch 215, the multiplexers 216 and 217, the mapping units 218 and 219, the call handling unit 220, and the virtual channel connection management unit 221 are configured.

Referring to Figure 2 will be described for the interoperability for interworking with the conventional telephone network in the access network to which the present invention is applied.

First, the signal is extracted from the TDM trunk of the E1 / T1 input from the PBXs 211 and 212, and the signal is terminated by the signal processing units 213 and 214. In the call handling unit 220, The interpretation of the signal for the call is made. Any timeslots in units of 64 kbps from the E1 / T1 trunk are switched to multiplexers 216 and 217 through switch 215 and then multiplexed according to destinations interpreted in call-by-call units.

In the mapping units 218 and 219, the multiplexed 64kbps channels are mapped to designated data octets of the ATM trunk (VCC), matched with AAL Type 1, and transmitted.

The virtual channel connection management unit 221 sets and releases a virtual channel connection (VCC) required by a remote PBX. ATM trunk creation method is largely divided into one-to-one mapping and many-to-one mapping according to the mapping of 64kbps voice channel and ATM VCC.

In the case of one-to-one mapping, one 64kbps voice channel is mapped to one ATM VCC. In this case, it is necessary to wait until 47 timeslots are filled for transmission of one cell. Because of this, it causes 5.875ms of delay, which means that the end-to-end delay of voice call is less than 25ms to ensure the quality, thus limiting the number of multiplexers or switches in the ATM network and additional echo cancellation in the network. -canceller) Requires functionality.

The one-to-one mapping scheme is preferably applied to small trunks that do not require switching and multiplexing functions, have little demand for voice calls, or in some cases, few call requests.

In many-to-one mapping, multiple voice channels are mapped to a single ATM VCC, so bandwidth can be properly utilized without causing delay. In particular, the case of many-to-one mapping is a very suitable method for a voice service capable of traffic prediction.

In addition, the present invention proposes a VTOA element having core functional units 213 to 219 for interoperability for interworking with an existing telephone network, and supports the aforementioned many-to-one doping scheme.

The VTOA device proposed in the present invention has a time slot switching function for all channels of eight E1 and DS1 lines (refer to the transmitting and receiving timeslot switching unit of FIG. 1 above) and the line emulation interoperability specification approved by the ATM forum. It accepts the vtoa-0078.000 function (see timeslot switching section of FIG. 1 above) and the AAL Type1 function of ITU-T I.363.1 (see FIG. 1 above).

3 is a structural diagram of an access network to which the present invention is applied for interworking with a conventional telephone network, including a Plain Old Telephony Service (POTS) 310, Optical Network Units (321) to 32n (ONU), and an Optical Loop (OLT) Termination 330).

In the figure, the ONUs 321 to 32n each comprise a channel unit (CU) and an interoperation function unit (IWF). OLT 330 also has an interoperable function (IWF).

In addition, a DLC (Digital Loop Carrier) is located in the POTS network.

FIG. 4 is a diagram illustrating an embodiment of the transmission AAL processing unit of FIG. 1, which includes a line interface (LIF) 121, a buffer 122, a SAR header generator 123, and a pointer generator 124. And an ATM payload generator 125, an RTS generator 126, a buffer 127, and a multiplexer 128.

The line interface 121 receives a frame number, a channel number, data, and signal data that are switched and input to prepare for making an ATM cell.

The buffer 122 is a signal buffer for collecting 32 signal information inputted for each line through the line interface 121.

The SAR header generator 123 has data and signals input for each line through the line interface 121, and uses an ATM cell payout using a pointer transferred from the pointer generator 124 or an RTS transferred from the RTS generator 126. A SAR header is generated and sent to the buffer 127 to generate a load.

The pointer generator 124 receives data and signals input for each line through the line interface 121, generates a pointer according to a request of the SAR header generator 123, and transmits the pointer to the SAR header generator 123.

The ATM payload generator 125 receives data and a signal input for each line through the line interface 121, generates an ATM cell payload according to a request of the SAR header generator 123, and delivers the ATM cell payload to the buffer 127. . Here, the SAR header generator 123 instructs the ATM payload generator 125 to generate and store the ATM cell payload in the buffer 127 when all SAR headers generated by the SAR header are stored in the buffer 127. do.

The RTS generator 126 receives data and signals input for each line through the line interface 121, generates an RTS according to a request of the SAR header generator 123, and delivers the RTS to the SAR header generator 123.

The multiplexer 128 multiplexes the SAR header and the ATM cell payload transferred from the buffer 128 and outputs the multiplexed SAR header to the transmitting ATM processor 130.

Meanwhile, the SAR header and the ATM cell payload stored in the buffer 128 during the AAL loopback test are transferred to the receiving AAL processing unit 170 through the interface processing unit 190 and used as information for restoring the clock of the receiving unit.

5 is a block diagram of an embodiment of the transmitting ATM processor of FIG. 1, wherein the ATM cell generator 131, the user buffer 132, the OAM cell processor 133, the OAM buffer 134, Firearm 135 is composed.

The ATM cell generator 131 generates an ATM cell by attaching an ATM header to an ATM payload that is multiplexed and input.

The user buffer 132 stores the ATM cell delivered from the ATM cell generator 131. When the stored ATM cell is in a FULL state, the user buffer 132 transfers the ATM cell to the multiplexer 135 according to the priority.

The OAM cell processing unit 133 notifies that there is an OAM cell which the central processing unit (CPU) writes the OAM cell to the memory 191 in the interface processing unit 190 and then reads to the transmitting ATM processing unit 130. In this case, the OAM cell in the memory 191 is read, and then CRC10 is calculated and stored in the OAM buffer 134.

The multiplexer 135 multiplexes and transfers an ATM cell stored in the user buffer 132 and an OAM cell stored in the OAM buffer 134. This is always performed when the storage state of the user buffer 132 is not full. The OAM cells stored in the OAM buffer 134 are preferentially multiplexed. In addition, the OAM cell is also input to the receiving ATM processor 160 through the interface processor 190 for a loopback test.

FIG. 6 is a diagram illustrating an embodiment of the transmission access processor of FIG. 1, which includes a demultiplexer 141, first in first out (FIFO) 142 and 143, and a multiplexer 144. It is composed. Here, the FIFOs 142 and 143 are asynchronous FIFOs.

The demultiplexer 141 demultiplexes a cell multiplexed and transmitted by the transmitting ATM processor 130 and delivers the demultiplexed cell to the FIFOs 142 and 143.

The multiplexer 144 multiplexes the cells transmitted from the FIFOs 142 and 143 to the utopia interface, where a level 1 master / slave function and a level 2 level are selected according to transmission mode selection. ) It performs the slave function and transfers it to the utopia interface.

FIG. 7 is a diagram illustrating an exemplary embodiment of the reception access processing unit of FIG. 1, which includes a demultiplexer 151, first in first out (FIFO) 152 and 153, and a multiplexer 154. It is composed. Here, the FIFOs 152 and 153 are asynchronous FIFOs.

The demultiplexer 151 demultiplexes a cell multiplexed by the transmitting ATM processor 130 and transmitted through the utopia interface and delivers the demultiplexer to the FIFOs 152 and 153. At this time, the demultiplexer 151 performs a level 1 master / slave function and a level 2 slave function according to the reception mode selection.

The multiplexer 154 multiplexes the cells transmitted from the FIFOs 152 and 153 to deliver them to the receiving ATM processor 160.

The transmission connection processing unit and the reception connection processing unit having the above structure will be described in more detail as follows.

The write clock of the FIFOs 142 and 143 of the transmission access processor 140 is a system clock and the read clock is a Utopia clock.

The write clock of the FIFOs 152 and 153 of the reception access processor 150 is a utopia clock and the read clock is a system clock.

In addition, two FIFOs are used to facilitate asynchronous processing, and the utopia interface provides the clock from the master and the slave receives the clock from the master, but here, both the master and the slave are externally clocked. By reducing the margin of timing (Margin), depending on the mode selection, it operates in both master / slave mode.

In addition, the internal interface of the transmission connection processing unit 140 and the reception connection processing unit 150 has a data width of 8 bits, but the external interface is 16 bits, so that 8 bits / 16 bits can be supported when processing the utopia interface. .

8 is a block diagram illustrating an exemplary embodiment of the receiving ATM processing unit of FIG. 1, wherein the selector 161, the ATM header remover 162, the demultiplexer 163, the OAM cell processor 164, and the OAM buffer ( 165).

The selector 161 selects a cell that is received and transmitted through the reception access processing unit 150 in the normal state, and transfers the selected cell to the ATM header remover 162. When the ATM loopback test is performed, the selector 161 selects a cell. The cell transmitted through the interface processor 190 is selected and transferred to the ATM header remover 162.

The ATM header remover 162 retrieves the cell passed from the selector 161 to remove the ATM header, and then passes the user cell to the demultiplexer 163 and the OAM cell to the OAM cell processor 164.

The demultiplexer 163 demultiplexes the user cell transmitted from the ATM header remover 162 and transmits the demultiplexer to the receiving AAL processor 170. In this case, the demultiplexer 163 transmits an ATM payload, which is a cell form in which an ATM header is substantially removed for each line.

The OAM cell processor 164 receives the OAM cell from the ATM header remover 162, performs a CRC10 check, stores the CRC10 in the OAM buffer 165, and stores the OAM cell in the two-cell OAM buffer 192 in the interface processor 190. Float an internal interrupt at 190.

FIG. 9 is an exemplary configuration diagram of the reception AAL processing unit of FIG. 1, which includes a selector 171, a SAR header searcher 172, a sequence processor 173, a pointer processor 174, and a cell output controller ( 175, an RTS extractor 176, an RTS buffer 177, an RTS generator 178, and a clock generator 179.

Here, the clock generator 179 is composed of a digital phase lock loop (DPLL).

The selector 171 selects and delivers the ATM payload delivered from the receiving ATM processing unit 160 in the normal state, and transfers it from the transmitting ATM processing unit 130 through the interface processing unit 190 in the AAL loopback test. Select and deliver the ATM payload.

The SAR header finder 172 searches a header of a cell transmitted from the selector 171, extracts a sequence number (SN), and determines whether a pointer exists.

The sequence processor 173 performs the fast algorithm in the appendix of ITU-T 1.363.1 by using the sequence number extracted from the SAR header finder 172 and the state of the sequence number to insert or remove the sequence. Determine the cell for.

The pointer processor 174 determines the state of the lost cell and the wrongly inserted cell through the determination result of the sequence processor 173, and compensates for the lost and misinserted cells by inserting the inserted cells.

The cell output controller 175 transparently transfers the cell to the reception timeslot switching unit 180 in the unstructured mode, and from the SAR header finder 172 in the structure mode. The pointer is distinguished based on the input pointer presence information, and the frame number, the channel number, and the data are transmitted to the reception time slot switching unit 180 by finding the boundary of the block (that is, the frame boundary) through the pointer.

After extracting the RTS from the SAR header delivered from the SAR header finder 172, the RTS extractor 176 collects the RTS of the extracted bit unit, collects the RTS value of the transmitter, and stores the extracted RTS in the RTS buffer 177. If necessary, the cell delay variation (CDV) is controlled by reading from the RTS buffer 177.

The RTS generator 178 generates an RTS according to the RTS delivered from the RTS buffer 177 and delivers the RTS to the clock generator 179.

The clock generator 179 compares the RTS generated by the RTS generator 178 with the RTS delivered from the RTS buffer 177 and generates a clock according to the comparison result. Here, since the generated clock can be used as a clock to the ATM network, it is not necessary to supply the clock used for the ATM network from the outside.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

As described above, the present invention provides a voice and telephone level service through an ATM network and connects a public switched telephone network and a narrowband network, thereby implementing two commercial time slot switches and a commercial chip 1 for processing AAL1 when implementing a VTOA device. It is possible to save money by substituting dogs, and also provides network operators with a competitive edge by reducing network construction operation and management costs through the redundant network configuration, improving network resource use efficiency, and strengthening service provision ability. have.

Claims (10)

In the device for providing voice and telephone level service in Asynchronous Transfer Mode (ATM) network, Transmission switching means for switching signals of each channel input from the outside; Transmission processing means for receiving the signals switched through the transmission switching means, generating and multiplexing an ATM cell payload, and transmitting an ATM cell generated by inserting an ATM header into the multiplexed ATM cell payload. ; And Sequence number and remaining time stamp extracted by searching for an ATM header of an ATM cell generated by the transmission processing means, and extracting a user cell by searching for an extracted Segmentation And Reassembly (SAR) header Receiving processing means for distinguishing the pointers using information and finding the boundary of the frame and transmitting the cell through the distinguished pointers Voice and telephone service providing device comprising a. The method of claim 1, Connection processing means for connecting signals transmitted and received between the switching means, the transmission processing means and the reception processing means. Apparatus for providing a voice and telephone level service further comprising. The method according to claim 1 or 2, The transmission processing means, Transmission cell processing means for multiplexing and outputting a SAR header and an ATM cell payload generated using signals input through the transmission switching means; Transmission ATM processing means for generating the ATM cell by attaching the ATM header to an ATM cell payload multiplexed from the transmission cell processing means; And Transmission connection means for transmitting the ATM cell generated by the transmission ATM processing means. Voice and telephone service providing device comprising a. The method of claim 3, wherein The transmission cell processing means, Connection means for connecting various signals input for each line through the transmission switching means; A SAR header generating means for requesting generation of a pointer and a remaining time stamp, and generating a SAR header by using a pointer or a remaining time stamp and a signal connected through the access means, and transmitting the generated SAR header to the SAR header generating means; Pointer generation means for receiving a signal connected through said access means according to a request of said SAR header generating means, generating said pointer, and transmitting it to said SAR header generating means; ATM payload generating means for receiving a signal connected through the access means according to a request of the SAR header generating means, generating the ATM cell payload, and delivering the same to the SAR header generating means; Storage means for temporarily storing and transmitting the generated SAR header and ATM cell payload; And Multiplexing means for multiplexing the SAR header and the ATM cell payload delivered from the storage means to the transmitting ATM processing means Voice and telephone service providing device comprising a. The method of claim 3, wherein The transmitting ATM processing means, ATM cell generating means for generating an ATM cell by attaching an ATM header to an ATM cell payload input from the transmitting cell processing means; First storage means for temporarily storing an ATM cell generated by said ATM cell generating means; An operation maintenance cell processing unit for reading and transmitting the operation maintenance cell provided by an external control processor; Second storage means for temporarily storing the operation maintenance cell transferred from the operation maintenance cell processing means; And Multiplexing means for multiplexing the ATM cell delivered from the first storage means and the operation maintenance cell delivered from the second storage means to the transmission access means Voice and telephone service providing device comprising a. The method of claim 3, wherein The transmission connection means, Demultiplexing means for demultiplexing a cell delivered from the transmitting ATM processing means; First and second storage means for temporarily storing the cells demultiplexed by the demultiplexing means; And Multiplexing means for multiplexing and transmitting the cells transmitted from the first and second storage means Voice and telephone service providing device comprising a. The method according to claim 1 or 2, The reception processing means, Reception connection means for connecting the ATM cell generated by the transmission processing means; Receiving ATM processing means for delivering a user cell to remove and extract an ATM header from a cell connected through the receiving access means; Receiving cell processing means for searching for a SAR header of a cell transmitted from the receiving ATM processing means, extracting a sequence number, and analyzing and compensating for a lost cell and a misinserted cell using the extracted sequence number; And Receiving switching means for switching the cell transmitted from the receiving cell processing means to the outside Voice and telephone service providing device comprising a. The method of claim 7, wherein The receiving connection means, Demultiplexing means for demultiplexing an ATM cell provided by said transmission processing means; First and second storage means for temporarily storing the cells demultiplexed by the demultiplexing means; And Multiplexing means for multiplexing the cells transmitted from said first and second storage means to said receiving ATM processing means Voice and telephone service providing device comprising a. The method of claim 7, wherein The receiving ATM processing means, Selection means for selectively transferring a cell transmitted from the transmission processing means and a cell transmitted from the reception connection means, according to external control; ATM header removing means for extracting a user cell and an operation maintenance cell by removing an ATM header from a cell delivered from the selection means; Demultiplexing means for demultiplexing a user cell which is an ATM cell payload transferred from said ATM header removing means, and delivering it to said receiving cell processing means; An operation maintenance cell processing means for inspecting whether the operation maintenance cell transmitted from the ATM header removing means is normal and delivering the same; And Storage means for temporarily storing and outputting the cell transmitted from the operation maintenance cell processing means; Voice and telephone service providing device comprising a. The method of claim 7, wherein The receiving cell processing means, Selecting means for selectively delivering an ATM cell payload delivered from the receiving ATM processing means and a cell delivered from the transmitting processing means, according to external control; SAR header retrieving means for retrieving the SAR header of the cell delivered from the selection means and extracting a sequence number; Sequence processing means for determining a cell for insertion or removal by using the sequence number extracted by the SAR header retrieving means and the state of the sequence number; Pointer processing means for compensating for lost cells and misinserted cells by identifying the states of lost cells and incorrectly inserted cells according to the determination result of the sequence processing means; Cell output control means for transferring the cell transmitted from said pointer processing means to said receive switching means; Residual time stamp extracting means for extracting a residual time stamp from a SAR header transmitted from said SAR header searching means; Storage means for temporarily storing the residual time stamp extracted by the residual time stamp extracting means; Residual time stamp generating means for generating a reference residual time stamp according to the residual time stamp transmitted from the storage means; And Clock generation means for comparing the reference time stamp with the time stamp received from the storage means and generating a clock according to the comparison result Voice and telephone service providing device comprising a.