JPH06197118A - Asynchrnous transfer mode subscriber's circuit and switchboard using the same - Google Patents

Abstract

PURPOSE:To connect an existing network with an ATM network by making a signal from an analog subscriber's line to an ATM. CONSTITUTION:The transfer of a PCM signal and a level signal between an analog subscriber's line 2 and an ATM cell multiplex circuit 8 is performed by making the signal to the ATM cell by an ALL processing circuit 5 for a PCM signal and an ATM layer processing circuit 7, and the transfer of the level signal between the analog subscriber's circuit 2 and the ATM cell multiplex circuit 8 is performed by making the signal to the ATM cell by an ALL processing circuit 6 for a level signal and the ATM layer processing circuit 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used as an asynchronous transfer mode switch for accommodating analog subscriber lines. It is used for an asynchronous transfer mode switch that accommodates analog subscriber lines by providing a cellizing function and converting the subscriber lines into asynchronous transfer mode. The conventional subscriber exchange is used as an upgraded asynchronous transfer mode exchange.

[0002]

2. Description of the Related Art In asynchronous transfer mode (ATM), all information is transferred in fixed-length packets called cells.
As a method of exchanging, various methods such as various speeds and various media can be efficiently realized at high speed as ISD.
N (Integrated Services Dig)
It is a basic technology for building an ital network. Such an ATM B-ISDN (Bro
existing ISDN) when constructing an existing S
TM (Synchronous Transfer M)
It is necessary to have a function of interconnecting with an ode) or connecting an existing terminal of the STM system or an existing subscriber line directly to the ATM network. In particular, it is an indispensable function in the process of efficiently accommodating the existing network in the integrated network by ATM.

As a method of converting an existing network into an ATM, an inter-network adapter is used to connect the existing network and an ATM network, or ST
A method to make ATM from the trunk line by adding a cell assembling / disassembling function to the trunk outgoing line of the M switch, or a subscriber line by deploying the cellizing function for multiple outgoing lines of the subscriber switch or subscriber line To ATM from the terminal, or by arranging an ATM adapter on the terminal side and directly connecting the existing terminal to the ATM.
It is possible to consider a method of making it possible to accommodate it in the net.

[0004]

However, in the prior art, the methods are roughly classified into the above-mentioned rough methods, and the respective realization methods have not been established yet.

The present invention has been made under such a background, and it is possible to connect an existing network to an ATM network by converting an analog subscriber line into ATM, and to replace the conventional subscriber exchange with an ATM exchange. In this case, it is an object of the present invention to provide an asynchronous transfer mode subscriber exchange in which an existing analog subscriber line can be accommodated in an ATM exchange efficiently and economically with the same interface as the conventional one.

[0006]

A first aspect of the present invention is an asynchronous transfer mode subscriber circuit for an analog line including an analog subscriber circuit for accommodating an analog subscriber line, wherein the asynchronous transfer mode of the output of the analog subscriber circuit is used. Adaptation layer processing and asynchronous transfer mode layer processing are performed and cells are created and given to the asynchronous transfer mode cell multiplex line.
It is characterized in that it includes means for receiving a cell from an asynchronous transfer mode cell multiplex line, disassembling the cell, and supplying the cell to the analog subscriber circuit.

According to the present invention, the processing means includes an echo canceller for performing echo control on the output pulse code modulation signal of the analog subscriber circuit, and an asynchronous transfer for the output pulse code modulation signal of the echo canceller. Pulse code modulation signal processing means for performing mode adaptation layer processing, level signal processing means for performing asynchronous transfer mode adaptation layer processing on the output level signal of the analog subscriber circuit, and this pulse code modulation signal processing means And an asynchronous transfer mode header is added to the output of the level signal processing means and an asynchronous transfer mode cell is given to the asynchronous transfer mode cell multiplex line, and the asynchronous transfer mode cell from the asynchronous transfer mode cell multiplex line is disassembled to obtain the pulse code. Modulation signal processing means and level signal processing means Asynchronous transfer mode layer processing means for giving the means, the pulse code modulation signal processing means decomposes the output of the asynchronous transfer mode layer processing means, and gives the means to the analog subscriber circuit via the echo canceller. In addition, the level signal processing means may include means for decomposing an output of the asynchronous transfer mode layer processing means and providing it to the analog subscriber circuit.

A second aspect of the present invention is an asynchronous transfer mode switch in which a plurality of asynchronous transfer mode subscriber circuits according to claim 1 are connected to an asynchronous transfer mode switch.

According to the present invention, in an asynchronous transfer mode switch according to a third aspect of the present invention, a pulse code modulation signal is transmitted and received between an asynchronous transfer mode cell multiplex line and the asynchronous transfer mode switch, and the asynchronous transfer mode cell multiplex is performed. Multiplex distribution circuit for distributing and transmitting level signal cells from the line, and input message for layer 2 processing including D channel link access procedure, asynchronous transfer mode adaptation layer processing type 1 and type 2 processing and asynchronous transfer A message processing circuit for performing mode layer processing, giving it to the asynchronous transfer mode switch, and disassembling the output of the asynchronous transfer mode switch into messages, and assembling / disassembling means for disassembling and assembling level signal cells transmitted and received by the multiplex distribution circuit. And based on the level signal from this assembly and disassembly means A means for generating a message and giving it to the message processing means, a means for giving the level signal to the assembling / disassembling means and a message from the message processing means when the message from the message processing means is a level signal. In the case of one of the signal reception instruction and the tone designation, a control device including a means for outputting one of them, a receiving circuit for receiving a push button in response to the push button reception instruction, and a tone designated by the tone designation. A tone transmitting circuit for transmitting and a signal processing circuit including an interface circuit for connecting the two circuits and the asynchronous transfer mode switch to each other to perform type 1 processing of asynchronous transfer mode adaptation processing, asynchronous transfer mode layer processing and interface, The control device is It generates a message based on a push-button signal from the serial receiver circuit characterized in that it comprises a means for providing the message processing circuit.

[0010]

Function: P between the analog subscriber circuit and the ATM switch
By transmitting and receiving the CM signal and the level signal in ATM cells, the analog subscriber line can be converted into ATM and the existing network can be connected to the ATM network.

To accommodate the STM line in the ATM network, CC
A function of assembling and disassembling into ATM cells, that is, an ATM adaptation process (ALL process) defined by ITT (International Telegraph and Telephone Consultative Committee) is essential. This ALL
A method of performing the processing where and how can be considered, and one of the methods is to accommodate the STM line in the conventional ATM switch and provide the ALL function at the entrance / exit to the multiple trunk line. Although this method is relatively easy to introduce, it cannot be said to be an ATM integrated network because an ATM switch will remain in the future even if ATM is advanced.

Since local calls are not converted to ATM,
The advantages of using ATM for local calls cannot be used. In view of this, the present invention performs the ALL processing for each subscriber line in the subscriber exchange, thereby
This is a method that enables TM conversion. In order to accommodate analog subscriber lines, the subscriber circuits, or BORs, must be provided for each line.
The SCHT circuit is required, and it is an idea of the present invention to add an ALL function to the BORSCHT function.
LSI with ALL function integrated with BORSCHT function
(Large Scale Integrated C
If it becomes an ircuit, there is a possibility that it will be possible to achieve sufficient economic efficiency in the future.

Considering the case of accommodating an analog subscriber line in an ATM network, it is necessary not only to convert the user information into an ATM cell, but also to process the signal system by the analog subscriber line in the ATM switch. . The types of signals include in-channel PCM signals such as PB signals and tone signals and level signals such as on-hook detection. The former requires a signal processing circuit such as a PB signal receiving circuit (PBR). To do. A method often used in conventional exchanges is a method in which a PB receiving circuit or the like is installed so as to be commonly used as a trunk and connected by a time switch whenever necessary. If this method is applied as it is, a time switch is required in addition to the ATM switch, and the interface between the subscriber line interface and the main body is ATM or S.
It will have both the TM and the switch configuration will be complicated. Also, a line for interfacing the level signal is required.

As in the conventional case, a signal circuit such as a PB receiving circuit is installed in the exchange body so as to be commonly used, and an ALL processing circuit is added to the device. An appropriate VCI (Virtual Channel Iden) is provided between the ATM subscriber circuit for each analog line and the main body of the ATM switch.
(Tiffer) is set, and according to the call control, for example, if the PB signal is received, the VCI is set by the ATM switch.
Cells are switched so as to be connected to the PB receiving circuit. As a result, the PB signal coming from the analog subscriber line is made into cells by the ALL processing type 1 in the subscriber corresponding portion and transmitted to the signal processing circuit by the ATM cell. In the signal processing circuit, the received cells are disassembled and returned to the original signal sequence, and the PB receiving circuit receives the PB signal and transmits the result to the control device. In this way, the line interface and the interface of the ATM switch become one type of ATM, and the configuration is simplified, and at the same time, all the information is converted into cells by the simplest type 1 in the ALL processing, the ATM for analog lines. The subscriber circuit can also be constructed relatively easily.

[0015]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an asynchronous transfer mode subscriber circuit according to an embodiment of the present invention.

In FIG. 1, an analog subscriber circuit 10 for an analog line includes an analog subscriber circuit 2 which accommodates an analog subscriber line 1.

A feature of the present invention is that asynchronous transfer mode adaptation layer processing (ALL processing) and asynchronous transfer mode layer processing (ATM layer processing) of the output of the analog subscriber circuit 2 are performed to form cells and asynchronous transfer. It is characterized in that it includes processing means for giving to the ATM cell multiplex line 8 as a mode cell multiplex line, receiving a cell from the ATM cell multiplex line 8, disassembling the cell and giving it to the analog subscriber circuit 2.

The processing means performs echo control on the output pulse code modulation signal of the analog subscriber circuit 2 and ALL on the output pulse code modulation signal (PCM signal) of the echo canceller 9. A PCM signal ALL processing circuit 5 as a pulse code modulation signal processing means for performing processing, and a level signal ALL processing circuit 6 as a level signal processing means for performing ALL processing on the output level signal of the analog subscriber circuit 2. , PCM signal ALL processing circuit 5 and level signal ALL processing circuit 6
Asynchronous transfer mode header (ATM header) is added to each output of
An ATM layer processing as an asynchronous transfer mode layer processing means which is given to the TM cell multiplex line 8 and decomposes the ATM cells from the ATM cell multiplex line 8 and is given to this PCM signal ALL processing circuit 5 and this level signal ALL processing circuit 6. Including the circuit 7 and the ALL processing circuit 5 for PCM signal is A
The level signal ALL processing circuit 6 decomposes the output of the ATM layer processing circuit 7 and decomposes the output of the ATM layer processing circuit 7 into an analog subscriber circuit 2 via the echo canceller 9. The operation of the asynchronous transfer mode subscriber circuit having such a configuration including the means for providing the circuit 2 will be described.

In FIG. 2, the analog subscriber circuit is SL.
IC (Subscriber Line Interface)
ACE Circuit) is an existing subscriber circuit and has a BORSCHT function such as power feeding, two-wire / four-wire conversion, analog-digital conversion, etc., and information such as voice from the analog subscriber line 1 is converted to analog-digital and μlaw or Alaw PCM (Pulse Code Modulation) coding is performed and output to the PCM signal input / output line 3, and the PCM signal from the PCM signal input / output line 3 is converted to an analog signal such as voice by analog / digital conversion and an analog subscriber line. Output to 1. Furthermore, the analog subscriber circuit 2
A level signal for off-hook monitoring of the subscriber is output to the level signal input / output line 4.

The ALL processing circuit 5 for PCM signal and the ALL processing circuit 6 for level signal are A for signals on the PCM signal input / output line 3 and level signal input / output line 4, respectively.
LL processing, that is, cell assembly / disassembly is performed. The ATM layer processing circuit 7 has an ATM processing and interface function, adds an appropriate header to the outputs of the PCM signal ALL processing circuit 5 and the level signal ALL processing circuit 6, and AT
The M cell is completed and output to the exchange main body through the ATM cell multiplex line 8. On the contrary, the ATM layer processing circuit 7
ATM cells are received from the ATM cell multiplex line 8 and
The header is decoded and given to the ALL processing circuit 5 for PCM signals and the ALL processing circuit 6 for level signals. ALL processing circuit 5 for PCM signal and ALL processing circuit 6 for level signal
Decelerates the output of the ATM layer processing circuit 7 and
It is given to the analog subscriber circuit 2 through the M signal input / output line 3 and the level signal input / output line 4.

The echo canceller 9 cancels the echo generated during the two-wire / four-wire conversion in the analog subscriber circuit 2 as necessary.

FIG. 2 is a block diagram of the asynchronous transfer mode switch according to the second embodiment of the present invention. FIG. 3 is a diagram showing the structure and encoding of a divided and assembled sub-layer protocol data unit handled by the type 1, type 3 and type 4 protocols of the asynchronous transfer mode adaptation layer processing of the asynchronous transfer mode switch according to the second embodiment of the present invention. is there. 3A shows the type 1 of ALL processing, FIG. 3B shows the type 3 of ALL processing, and FIG. 3C shows the type 4 of ALL processing. Furthermore, SN is a sequence number, SNP is a sequence number protection, SAR-PDU is a fragmentation sublayer protocol data unit, ST is a segment type,
Res. Is a reserve field, LI is a length display, CR
C indicates a redundancy check code and MID indicates a multiplexing identifier.

In FIG. 2, 10A represents one analog line ATM subscriber circuit, and the multiplex distribution circuit 11 multiplexes the ATM cells of a plurality of analog line ATM subscriber circuits 10A to the ATM switch 12. Output. The analog line ATM subscriber circuit 10A has the same configuration as the analog line ATM subscriber circuit 10 shown in FIG. 1, except that the PCM signal ALL processing circuit and the level signal A
The LL processing circuit is different in that it performs the type 1 ALL processing shown in FIG.

Interface circuit 1 of signal processing circuit 13
A circuit 4 performs ATM layer processing, type 1 ALL processing and the like, and interfaces with the ATM switch 12 to transmit and receive cells. For example, the interface circuit 14 outputs the PB signal cell from the ATM switch 12 to the PB signal receiving circuit 15 after returning it to the original signal sequence. In addition, the tones such as busy tone (BT) generated by the tone transmission circuit 16 are made into cells and the ATM switch 12
Appropriate ATM subscriber circuit 10 for analog lines via
Send to A. The signal processing circuit 13 has a processing capability for a plurality of lines.

The multiplex distribution circuit 11 is an AT for analog lines.
The ATM cells from the M subscriber circuit 10A are distributed, the PCM signal cells are output to the ATM switch 12, and the level signal cells are output to the level signal cell assembling / disassembling circuit 17. Further, the output cells of the ATM switch 12 and the level signal cell assembling / disassembling circuit 17 are multiplexed to make an appropriate analog line AT.
Output to the M subscriber circuit 10A. The level signal cell assembling / disassembling circuit 17 transmits / receives cellized level signals, decomposes the level signal cells distributed by the multiplex distributing circuit 11, and outputs the original signal output to the level signal input / output line 4. The signal sequence is returned to the control device 18. In addition, the level signal from the control device 18 is converted into cells, and the multiplex distribution circuit 11
Output to. The control device 18 monitors the signal of each channel and performs call processing accordingly. Message processing circuit 1
9 transmits / receives a call control signal in the form of a message to / from another ATM exchange. Layer 2 processing circuit 20 is LAP
D (link access procedure for D channel, Link Ac
3) and the layer 1 processing circuit 21 performs the layer 2 processing such as process procedure).
All processing types 3 and 4 shown in (c) and ATM
Performs layer processing, etc. That is, the message is generated or decoded by the control device 18, and the message processing circuit 19 processes the layers 1 and 2 to interface with the network using ATM cells.

In FIG. 2, the VCI (Vir) between the ATM subscriber circuit 10A for each analog line and the main body of the ATM switch is shown.
As an example of the setting method of the real channel identifier, ATM for each analog line is used.
PVC (Permanent) for each subscriber circuit 10A
Virtual Circuit) is set, and level signals such as supervisory signals are always received and monitored by the ATM switch body. For example, if the terminal goes off-hook, it becomes a level signal change, and the ATM subscriber circuit 10 for analog lines is used.
It is made into cells at A and transmitted to the control device 18 according to PVC. The control device 18 detects off-hook based on the information, and thereafter the call control process is executed in accordance with the detected off-hook condition.

At this time, for example, the control device 18 sends the control signal cell to the analog line ATM subscriber circuit 10A through the level signal cell assembling / disassembling circuit 17 to set a new VCI, and dial tone or dial tone according to the VCI. The PB signal is transmitted and received. When the call setting is completed and the call is established, the user information is cellized by adding an appropriate ATM header in the analog subscriber ATM circuit 10A, and is routed by the ATM switch 12.

[0029]

As described above, according to the present invention, the ATM
In constructing the network, the analog subscriber line, which is presently a huge amount of equipment, can be accommodated as it is in the ATM network, and there is an excellent effect that it can contribute to the rapid and economical advancement of ATM conversion. In addition, LSI (Large Scale)
If the economy and downsizing can be realized by the integrated circuit, etc., existing services such as a telephone can be provided more economically. Further, by providing a level signal assembling / disassembling circuit, a signal processing circuit, a message processing circuit and a control device in the ATM switch, the analog subscriber circuit for analog lines can be simplified.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an asynchronous transfer mode subscriber circuit according to an embodiment of the present invention.

FIG. 2 is a block diagram of an asynchronous transfer mode switch according to another embodiment of the present invention.

FIG. 3 is a diagram showing the structure and encoding of a divided / assembled sublayer protocol data unit handled by the type 1, type 3 and type 4 protocols of the asynchronous transfer mode adaptation layer processing of the asynchronous transfer mode switch according to the second embodiment of the present invention. .

[Explanation of symbols]

1 analog subscriber line 2 analog subscriber circuit 3 PCM signal input / output line 4 level signal input / output line 5 PCM signal ALL processing circuit 6 level signal ALL processing circuit 7 ATM layer processing circuit 8 ATM cell multiplex line 9 echo canceller 10 10A ATM subscriber circuit for analog line 11 Multiplexing circuit 12 ATM switch 13 Signal processing circuit 14 Interface circuit 15 PB signal receiving circuit 16 Tone transmitting circuit 17 Level signal cell assembling / disassembling circuit 18 Controller 19 Message processing circuit 20 Layer 2 processing circuit 21 Layer 1 processing circuit CRC Redundancy check code LI Length display MID Multiplexing identifier SAR-PDU Division assembly sub-layer protocol data unit SN sequence number SNP sequence number protection Res. Reserve field

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H04Q 11/04 9076-5K H04Q 11/04 R

Claims (4)

[Claims] 1. In an asynchronous transfer mode subscriber circuit including an analog subscriber circuit accommodating an analog subscriber line, an asynchronous transfer mode adaptation process and an asynchronous transfer mode layer process of an output of the analog subscriber circuit are performed to form cells. Asynchronous transfer mode Cell multiplex,
An asynchronous transfer mode subscriber circuit, comprising processing means for receiving a cell from an asynchronous transfer mode cell multiplex line, disassembling the cell, and providing the cell to the analog subscriber circuit. 2. The processing means includes an echo canceller for performing echo control on an output pulse code modulated signal of the analog subscriber circuit, and an asynchronous transfer mode adaptation layer process for an output pulse code modulated signal of the echo canceller. Pulse code modulated signal processing means, level signal processing means for performing asynchronous transfer mode adaptation layer processing on the output level signal of the analog subscriber circuit, and pulse code modulated signal processing means and level signal processing means Asynchronous transfer mode headers are added to the outputs of the processing means, asynchronous transfer mode cells are given to the asynchronous transfer mode cell multiplex line, the asynchronous transfer mode cells from the asynchronous transfer mode cell multiplex line are disassembled, and this pulse code modulation signal processing is performed. Means and means for processing this level signal Synchronous transfer mode layer processing means, the pulse code modulation signal processing means includes means for decomposing the output of the asynchronous transfer mode layer processing means and giving it to the analog subscriber circuit via the echo canceller, 2. The asynchronous transfer mode subscriber circuit according to claim 1, wherein the level signal processing means includes means for decomposing the output of the asynchronous transfer mode layer processing means and applying it to the analog subscriber circuit. 3. An asynchronous transfer mode switch in which a plurality of asynchronous transfer mode subscriber circuits according to claim 1 are connected to an asynchronous transfer mode switch. 4. The asynchronous transfer mode switch according to claim 3, wherein a pulse code modulation signal is transmitted and received between an asynchronous transfer mode cell multiplex line and the asynchronous transfer mode switch,
Asynchronous transfer mode cell Multiplexing circuit for distributing and transmitting level signal cells from multiplex line, layer 2 processing including input access message for D channel link access procedure, type 1 and type of asynchronous transfer mode adaptation layer processing (2) A message processing circuit that performs two processes and an asynchronous transfer mode layer process, gives the asynchronous transfer mode switch, and decomposes the output of the asynchronous transfer mode switch into messages, and disassembles and assembles level signal cells transmitted and received by the multiplex distribution circuit. And a means for generating a message based on the level signal from the assembly and disassembly means and giving it to the message processing means. If the message from the message processing means is a level signal, the level signal is Assembling and disassembling means and When the message from the message processing means is one of a push button signal reception instruction and a tone designation, a control device including means for outputting one of them, a receiving circuit for receiving a push button according to the push button reception instruction, A tone transmitting circuit for transmitting a tone designated by a tone designation, and an interface for connecting the two circuits with the asynchronous transfer mode switch to perform type 1 processing of asynchronous transfer mode adaptation layer processing, asynchronous transfer mode layer processing and interface A signal processing circuit including a circuit, wherein the control device includes means for generating a message based on a push button signal from the receiving circuit and supplying the message to the message processing circuit.