CN1170384C - Integrated analogldigital telephone interface - Google Patents

Abstract

A remote terminal (40) for use at an access network node of a network (10) provides a plurality of telecommunications services, the remote terminal (40) providing selected ones of the telecommunications services to at least one corresponding terminal device (62). The telecommunications services provided by the network include a plain old telephone service (POTS) (16), an integrated service digital network service (ISDN) (18), and internet services such as xDSN. In one embodiment, the remote terminal (40) comprises: a digital signal processor (120) coupled for communication with the network, the digital signal processor (120) having a plurality of terminal ports; and a plurality of subscriber line interface circuits (SLIC's) (124), each of the SLIC's (124) providing an interface between a corresponding one of the terminal ports and at least one corresponding terminal device (62), the digital signal processor (120) being configured to provide selected ones of the telecommunications services to corresponding ones of the terminal devices.

Description

Integrated analog/digital telephony interface

Cross reference to related application

It is the senior interest of 60/073,127 U.S. Patent application that the application requires on January 30th, 1998 application, " an integrated analog/digital telephone network interface circuit design " by name, sequence number.Now it being incorporated into this sentences for referencial use.

Technical field

Generally speaking, the present invention relates to be used for provide telecommunication service method and device to end user's terminal.More particularly, the present invention relates to employed a kind of Line cards in the remote terminal on an accesses network node, this Line cards comprises an adaptive subscriber line interface circuit (SLLC).

Background technology

In telecommunication industry,, copper cash loop complete set of equipments on a large scale is used for support to analog telephone usually by a common old-fashioned telephone service (POTS) is provided.In the whole world, use extensive copper cash loop complete set of equipments to submit to the coml importance of digital service (being called ISDN) just to grow with each passing day.A kind of novel service is called digital subscriber line (xDSL) service of " x " type, also successfully has been introduced into home loop.In order to describe the present invention better, the xDSL service relates to the subscriber's line service of all universal classes, comprises Symmetric Digital Subscriber Line (aDSL) service, HDSL High-Speed Digital Subscriber Line (hDSL) service and single digital subscriber circuit (sDSL) service.For central office equipment (for example an interchanger or a router) is linked to each other with user on the copper cash loop, designed a kind of access interface, this interface is called network interface.

In traditional system, an analog interface (being called subscriber line interface circuit (SLLC)) is connected in the phone of a ministerial standard, so that a POTS service to be provided.A digital interface (being called ISDN " U " interface) is connected in an ISDN terminal, so that ISDN BRI 2B+D to be provided service.Use another digital interface (being called the xDSL interface) to provide visit to internet (Internet) to end user's terminal equipment.

Formerly have in the technological system, for dissimilar telecommunication services is provided, telecommunication operator must use different network interface ports to carry out interface with different user.In a series of copper cash loop, specify each loop that one type service is provided.For a single service specified, the user only can use the loop that is connected in its family.

Article one, local user's circuit is connected in the network interface that is in switch and a user between the user terminal.For example, user can have the selection of signatory POST or ISDN service.When the user contracts POST, then the copper cash loop is connected on the POTS Line cards.Subscriber line interface at a POTS Line cards can provide BORCHT function and PCM Codec function usually.The ISDN encoding function comprises 2B1Q coding and 2B+D function.When the signatory ISDN of user serves, then the copper cash loop is connected in an isdn line an outpost of the tax office.Do not exist the mixing of Line cards is used with coupling.

Summary of the invention

The invention provides a remote terminal that can on the accesses network node of a network that the service of a series of telecommunications can be provided, be used, this remote terminal at least can to a corresponding terminal device provide a series of telecommunications serve in some selected services.Comprise POTS, ISDN and Internet service (for example xDSN) by the telecommunication service that network provided.

In one embodiment, remote terminal comprises: the digital signal processor of a coupling, be used for and the communicating by letter of network, and this digital signal processor has a series of terminal prots; And a series of subscriber line interface circuits (SLIC), wherein each SLIC provides an interface between a relevant terminal port and at least one corresponding terminal device, and digital signal processor disposed, so that some selected services in a series of telecommunications services are offered more corresponding terminal equipments.

In another embodiment, remote terminal comprises: the digital signal processor of a coupling is used for and network service; A subscriber line interface circuit (SLIC) provides a specific terminal equipment and the communication between the digital signal processor; A memory cell, be used for the instruction readable, that carried out by digital signal processor of storage computation machine, these instructions are used to realize an adaptive telecommunication service process, this process comprises some steps like this: determine the needed selected telecommunication service of specific terminal equipment automatically, and provide selected telecommunication service to this particular terminal device.SILC comprises a protective circuit, and the device that is used to provide BORCHT and PCM Codec function.

A Line cards of remote terminal of the present invention can be manually or automatically is reconfigured in POTS or ISDN and uses.By software arrangements or automatic wireline inspection, this dual-use line an outpost of the tax office both can be used for providing POTS service, also can be used for providing ISDN service.Use this scheme, for multiple service arrangement, the operator will only need use a kind of Line cards.

The design of ISDN u interface is based on ANSI T1S1 standard.SLIC may comprise an ISDNU echo cancellation transponder chip.SLIC uses Digital Signal Processing to provide xDSL function as a DSL interface circuit.In addition, SLIC also provides the design data function on the speech.

Advantage of the present invention comprises: high-performance, low expense and be easy to exploitation.

A significant advantage of the present invention is that a single Line cards can be used for some selected in end user's terminal provides a series of services services.Because a single line card port and copper cash loop can be used for providing a series of service to end user's terminal selectively, therefore can minimize spending of hardware.

By following detailed description, and to the reference of a plurality of accompanying drawings to the embodiment that recommended, the present invention above-mentioned and other target, characteristic and advantage will become fairly obvious.

Description of drawings

Fig. 1 is the schematic block diagram of a multi-service network system according to the invention, and this system comprises: central authorities' office telecommunication equipment that common old-fashioned telephone service (POTS), an integrated services digital network (ISDN) service and Internet service can be provided; An accesses network node that has an intelligentized and adaptive subscriber line interface circuit according to the invention (slic circuit);

Fig. 2 is the schematic block diagram of a Line cards of remote terminal, and this Line cards comprises a digital signal processor;

Fig. 3 is the schematic block diagram of a Line cards that can be disposed again by software according to the invention;

Fig. 4 is the block diagram to the detailed description of a slic circuit among Fig. 1;

Fig. 5 describes is the block diagram of an optional embodiment of one of the Line cards of remote terminal shown in Figure 1, and this Line cards provides a TDM interface and an atm interface;

Fig. 6 is a flow chart, explanation be a process according to the invention, be used for determining the type of the end-user device that one of the Line cards with remote terminal is coupled; And

Fig. 7～Figure 12 has carried out more detailed description to Line cards.

Embodiment

The present invention provides an integrated scheme that is used for the planned network interface circuit at this, allows a telecommunication operator to provide different services from the identical network port, and will allow the user to use different services on identical copper cash loop.

The invention provides a kind of network interface, this interface not only can stop the startup POST circuit of a conventional circuit, meanwhile, can also stop an ISDN BRI 2B1Q circuit and an xDSL circuit.Provide a kind of POTS that realizes a no converter and with the method for the slic circuit of ISDN compatibility; A kind of speech CODEC that makes up and method of ISDN 2B1Q echo canceller of realizing is provided, and this echo canceller has advanced features such as impedance Control, gain controlling and echo cancellation.The present invention also provides a kind of exchange of making up and method of packet interface of realizing.The required a kind of COS of a particular terminal device that network interface according to the invention provides a kind of automatic detection to be connected in this interface, and commutative method to the required mode of operation that service is provided of this particular terminal device.In telecommunication market, this novel SLIC goes far towards the deployment of N-ISDN service, thereby it is believed that it is having very big potentiality aspect linear velocity of performance interface, promptly from ISDN BRI to interface compatibility, the linear velocity of interface can be not quite similar.Additional thought can convert SLIC to a system that is driven by software, wherein can constantly introduce newer modulation scheme in the xDSL scheme of a more advanced POTS (having speech quality and speech coding and decoding characteristics preferably) and renewal.

The telephone network interface architecture

An integrated network line interface circuit allows simultaneously port to be connected in two kinds of dissimilar terminal equipments, and according to the terminal that is activated, network interface will provide compatible service to this terminal.

In all situations, can be connected in integrated network interface circuit to a traditional analog telephone or an ISDN terminal, meanwhile, each connection can provide the service of a compatibility to its terminal separately.

The invention provides a telecommunication subscriber line interface, this subscriber line interface can provide POTS and ISDN composite services simultaneously.A user can use common phone (POTS) and ISDN terminal simultaneously on same copper cash loop.Use an advantage of this scheme to be, for voice service, the user does not need to buy an ISDN terminal.

The invention provides a subscriber line interface, at the Internet access applications, this subscriber line interface provides POTS and xDSL composite services.This user interface can support the data on POTS and the speech to use simultaneously.This this user interface is also supported the voice service of POTS and high-quality.When the CODEC of a high-quality is end-to-end when being detected, the CODEC that is provided by SLIC provides a kind of speech coding mechanism of having improved, and with by the enterprising line data transmission in the loop, supports better speech quality.

Fig. 1 has provided the schematic block diagram of a multi-service network system according to the invention at 10 places, this system comprises: central authorities' office telecommunication equipment that service of a common old-fashioned telephone service (POST), an integrated services digital network (ISDN) and Internet service (for example xDSL, a kind of digital subscriber line service) are provided; And an accesses network node, this node comprises a Line cards at least, this Line cards has an intelligentized and adaptive subscriber line interface circuit according to the invention (slic circuit).The accesses network node that is coupled is used for communicating by letter by an optical fiber link and central authorities offices telecommunication equipment.

Central authorities' office equipment comprises: a central office switching system 12; Central authorities' office terminal 14 of a coupling, be used for communicating by a POTS service link 16 and switch 12, POTS service link 16 can be a T1/E1 link, also be coupled by an isdn link 18 and interchanger 12, isdn link 18 can be the link of a TR303 or V5.1/V5.2 type, is used to provide ISDN service; A router two 4 that has the port 26 of a coupling is used for and the communicating by letter an of port 28 of central authorities offices terminal 14, and the port 30 of a coupling, is used for and the communicating by letter an of internet 32.

The accesses network node comprises: a remote terminal 40, this terminal has the optical fiber link port 42 of a coupling, be used for the communicating by letter of port 44 by one first optical fiber link 46 and central authorities offices terminal 14, the second optical fiber link port 48 of a coupling, be used for by the communicating by letter of the whole port 50 of one second optical fiber link 52 and central authorities offices, and a series of terminal prot 49; One first end user site 60, it comprises a phone 62 that has the port 64 of a coupling, be used for and the communicating by letter of one first port 49a of remote terminal 40, and the isdn device 68 of a coupling, be used for and the communicating by letter of one second port 49b of remote terminal 40; An automatic mapping service-user site 80, it comprises the isdn device 82 of a coupling, is used for and the communicating by letter of one the 3rd port 49c of remote terminal, the phone 86 of a coupling also is used for communicating by the 3rd port 49c and remote terminal; And the data user application site 90 on speech, it has the isdn device 92 of a coupling, is used for and the communicating by letter of one the 4th port 49d of remote terminal 40, and the personal computer 96 of a coupling is used for and the communicating by letter of isdn device 92; And the phone 100 of a coupling, also be used for communicating by letter by the 4th port 49d and remote terminal.

Remote terminal 40 comprises an internal bus 102; An optical fiber interface 104 that bus 102 is coupled in optical fiber link port 42; An optical fiber link interface 106 that bus 102 is coupled in optical fiber link port 48; A series of Line cards 110, the port one 12 that each has a coupling is used for and the communicating by letter of internal bus 102; And a central processing unit (CPU) 116, it has the port one 18 of a coupling, is used for and the communicating by letter of internal bus 102.Internal bus 102 can be time-division multiplex (TDM) universal serial bus or order terminal (ST) bus.

Each Line cards 110 comprises: at least one digital signal processor (DSP) 120; And a series of (N) according to the invention subscriber line interface circuit (slic circuit) 124, each slic circuit has the port one 25 of a coupling, be used for and the communicating by letter of N the port one 26 corresponding ports of DSP 120, and user side's port of a coupling, or terminal prot 127, be used for the communicating by letter of one of terminal prot 49 and a terminal equipment by remote terminal.In one embodiment, each in the Line cards 110 all comprises a DSP 120 and N=4 slic circuit 124, and each all is coupled in one of 4 port ones 26 of DSP120.In an optional embodiment, each in the Line cards 110 can comprise a DSP 120, and a slic circuit 124 that is coupled in the port one 26 of DSP 120.This design alternative is based on the performance of employed DSP 120.

Explained further that as following according to the present invention, the effect of each Line cards 110 is the types that detect a remote equipment relevant with it.For example, first Line cards 110 (being expressed as LC-1) can automatically detect: whether the end-user device 64 that is coupled in port 49a is a phone that needs the POTS service.LC-1 also can automatically detect: whether the end-user device 68 that is coupled in port 49b is an isdn device that needs the ISDN service.

(it comprises isdn device 82 and phone 86 for automatic mapping service-user site 80, both are and communicate with port 49c and be coupled), second Line cards 110 (being represented with LC-2) automatically detects which end-user device (isdn device 82, or phone 86) currently be activated, online or off-line.For the data user application site 90 on the speech (it comprises isdn device 92 and the phone 100 that is coupled with PC 96, and both are with the communicating by letter of port 49d of remote terminal 40 and are coupled).The 3rd Line cards 110 (being represented with LC-3) detects automatically which end-user device (isdn device 92, or phone 100) is current to be activated.

According to the present invention, DSP 120 software operation (not shown in the drawings) below will further be described this, be used for detecting automatically the type of the end-user device that is coupled in the corresponding port.After the type of end-user device is determined, DSP 120 is according to a control signal agreement, communicate with central office terminal 14 by a passage that is based upon in the optical fiber link 46,52, with the COS of required service on the specific end user's port that indicates Line cards.Central authorities' office terminal 14 and remote terminal 40 provide a service map function, so that its COS of needed telecommunication service to be provided to each end-user device: ISDN, POTS or an Internet service.

For example, the isdn device that is coupled with PC 96 92 is current to be activated if the 3rd Line cards 110 (being represented by LC-3) detects, then the LC-3 of remote terminal communicates with central office terminal 14 by a passage that is based upon in the optical fiber link, needs Internet service to indicate on the port 49d.Central authorities offices terminal 14 and remote terminal 40 are responded this, promptly by carrying out the map function, the port 49d of Internet service by remote terminal are provided in data user application site 90 on the speech.

Fig. 2 has provided a schematic block diagram of one of the Line cards 110 of remote terminal 40 (Fig. 1) at 150 places.Described Line cards 110 comprises: DSP 120, and it has first port one 52 of a coupling, and the port one 12 with by Line cards 110 receives a transmission of data signals (T from internal bus 102 _xD), the port one 54 of a coupling is to receive the transmission data clock signal (T from internal bus 102 by port one 12 _xC), the port one 56 of a coupling is to receive a data-signal (R from internal data bus _xD), the port one 58 of a coupling is to receive a data clock signal (R from this bus _xC), the port one 60 of a coupling is in order to receive a transmission frame signal (T from this bus _xFRAME), the port one 62 of a coupling is in order to receive a frame signal (R from this bus _xFRAME); And a series of (N) slic circuit 124 (Figure 1A).

Each slic circuit 124 comprises: the change-over circuit of a digital to analogy (D/A change-over circuit) 170, this change-over circuit has the port one 72 of a coupling, to receive the digitally coded information from a corresponding port in a series of (N) port one 28 of DSP 120; The hybrid circuit 176 of one 2 line/4 lines, it have a coupling input port (in order to by one first line to 178 analog informations that receive from D/A change-over circuit 170), loop port one 80, end port 182, one be coupled in the DC port one 84 of 24/48 V DC power supply device and the RING port one 86 of a coupling (exchanging) in order to receive 90V; A protective circuit 190, it has a loop port one 92 of the loop port one 80 that is connected in circuit 176, an end port 194 that is connected in the end port 182 of circuit 176, and one be used for the output port 196 that communicates with end user's port 49a, 49b, 49c, the corresponding port of 49d (Fig. 1); And the change-over circuit of an analog to digital (A/D change-over circuit) 200, it has the input port (in order to pass through second line to 202 information that receive from the analog encoding of circuit 176) of a coupling, and the output port 204 of a coupling (in order to digitally coded information is provided in the corresponding ports 128 of DSP 120).

According to the present invention, each Line cards 110 all provides additional Digital Signal Processing function, and these functions comprise coding and decoding (CODEC) function and echo cancellation function.

Each Line cards 110 is adaptive to different impedance specifications, is adaptive to different line balances, is adaptive to different gains and comprises the a-rule and the PCM code of u-rule.

In one embodiment, provide the software that in each Line cards 110, to be carried out, with the PCMCODEC that provides to use the reinforcement of 64bps transmission (obtaining speech quality preferably) to use compression.

The present invention also provides a kind of method of detecting user's line, and both towards switch also user oriented, this method has been used built-in software in the Line cards 110.In addition, also provide a kind of frequency self-adaption mechanism, be used to expand the digital bandwidth in DSL loop.

In one embodiment, Line cards provides TDM and the atm interface that can be selected.

Additional characteristic and function comprise: integrated PCM CODEC/SLIC and ISDN U LIU; Serial and parallel interface mechanism; Circuit and pack mode operation; Data on BORCHT, coding and decoding and the speech integrated; Remote power feeding ability at POTS and ISDN U; Support to trunk interface (COIC) application.

Each Line cards can be adaptive to the transmission gain standard of the different telecommunication standards of different impedances and country variant.Each Line cards all comprises and is used for handling automatically the long and short software that effectively reaches balance.Each Line cards also all provides: at the coding flexibly and the decoding of a-rule, u-rule and linear signal; Detection and generation at the additional function of DTMF, FSK, TONE; And inside and outside diagnostic function.

In one embodiment, the ability of DSP is defined by parameter, and these parameters are: ISDN 5～10mips, A/D 100khz/ISDN port, 8khz/SLIC and D/A 100khz.

Each Line cards all is controlled, programmable, and so that interface to be provided selectively, these interfaces comprise: an analog interface, ISDN ' U ' interface, a loop start interface and a HDLC interface.ISDN ' U ' is configured to NT or LT, and remote power supply is provided.Automatically ISSDN, loop start trunk line and analog telephone equipment.

Each SLIC 124 provides BORCHT function, autobalance and loop roaming.

Numeral side's interface is used for serial PCM 2.048,4.096 and 8.192Mb/s I/O; Two synchronizers at different directions; And Microprocessor Interface.

The built-in function of analog interface comprises programmable impedance, programmable gain and selectable coding.

For ISDN, Line cards provides transmission and has received rule, echo cancellation and the automatic adjustment to gaining.

A realization comprises: 4 passages with light-heavy front end-terminal hybrid circuit; The ISDNU Interface design of a no converter; A special line balance controlling schemes; A Design of Bandpass (can work) at voice signal and ISDN 2B1Q signal; A series of methods that are used to detect analog telephone terminal and ISDN U terminal; And a series of methods that are used for exchange between detection of dynamic analog telephony and the service of digital ISDN u interface.

The present invention also provides: an integrated scheme that is used for realizing at a DSP PCM CODEC and ISDN echo canceller circuit function; One both can be used for the special protective circuit that simulation application also can be used for digital application.

Fig. 3 has provided the block diagram of the realization of a Line cards that can be disposed again by software at 250 places.In this embodiment, each slic circuit 124 of Line cards 110 is coupled, to receive the TDM signals by internal bus 112 and from the CPU control signal of CPU 116.

Fig. 4 has provided a block diagram that describes the slic circuit 124 (Fig. 1) of an embodiment according to the invention in detail at 300 places.In described embodiment, slic circuit 124 comprises a control bus 318 that is coupled in digital signal processor 120 (Fig. 1) by port one 28.A/D change-over circuit 200 comprises: an amplifier 310, amplifier 310 comprises the input 312 of a coupling, to receive a analog signal from circuit 176, an output 314, and the input 316 of a coupling, to receive a control signal from DSP (Fig. 2) by control bus 318; A filter 320, it has the input 322 of a coupling, to receive the signal that from the output 314 of amplifier 310 one has amplified, the control input 324 of a coupling, with a control signal that receives from DSP by bus 318, and an output 326; An A/D converter 330, it has the input 332 of a coupling, to receive a signal from the output 322 of filter 320, the control input 334 of a coupling, with a control signal that receives from DSP by bus 318, and the output 336 of a coupling, to provide a signal that is loaded with digital code information to DSP 120 (Fig. 2) by port one 28.In one embodiment, A/D converter 330 operates on the sample rate of 14 * 1 bits * 4k/s or 8 * 1 bits * 80k/s.

The D/A change-over circuit 170 of slic circuit 124 comprises: the transducer of a digital to analogy (D/A converter) 342, it has the input 344 of a coupling, with a digitally coded signal that receives from DSP120 (Fig. 2) by port one 28, and the control of coupling input 346, with a control signal that receives from DSP by control bus 318, and the output 344 that an analog signal is provided; An input filter 350, it has the data input 352 of a coupling, to receive a analog signal from A/D converter 342, the control input 354 of a coupling, with a control signal that receives from DSP by control bus 318, and the output 356 of coupling, so that the analog signal of a filtering to be provided; And input amplifier 360, it has the control input 362 of a coupling, with the analog signal that accepts filter, the control input 364 of a coupling, with a control signal that receives from DSP by control bus 318, and the output 366 of a coupling, so that an analog signal to be provided to change-over circuit 176.In one embodiment, D/A converter 342 operates on the sampling rate of 14 * 1 bits * 8k/s or 8 * 1 bits * 80k/s.

Protective circuit 190 comprises: a battery feeding means 370, battery feeding means 370 have and are coupled in a voltage supply device and (provide a voltage level V _BAT) input 372 and one output 374; Electric current and voltage sensor control device 380, it has 382, one ports 384 of input and the port 386 that are coupled in the output 374 of battery feeding means; A protective circuit 390, it has 394 and loop outputs 396 of 392, terminal outputs of an input; And an overcurrent protective device 400, it has a port 402 that is connected in the port 386 of device 380.Protective circuit 190 can be disposed by software.Electric current and 380 responses of voltage sensor control device change electric current and voltage threshold parameter by the control signal that digital signal processor provided.

Fig. 5 has provided the block diagram of an optional embodiment of a Line cards 110 of remote terminal (Fig. 1) at 410 places.Described Line cards comprises the random access storage device (RAM) 412 of a coupling, is used for and the communicating by letter of DSP 120; The read-only memory of a coupling (ROM) 414 is used for and the communicating by letter of DSP 120; The slic circuit 124 of a coupling is used for and the communicating by letter of DSP; The atm interface 416 of a coupling provides communicating by letter by a CUBIC bus and atm network; The TDM interface 418 of a coupling provides communicating by letter by a TDM universal serial bus or ST bus and TDM network; A cpu i/f 420; And Serial Control bus 422.

Fig. 6 has provided the flow chart of an explanation process according to the invention at 450 places, this process is used for determining the type of the end-user device that is coupled by an end user's port and a Line cards 110 (Fig. 1).Described process is from step 452, and wherein, by energized (as adopting an isdn device, or having plucked under the situation of phone), equipment is that end-user device is activated.Processing procedure advances to 454 from step 452, and at 454 places, DSP determines whether require any data configuration with communicating by letter of end-user device.Default setting is a Speech Communication, yet for an isdn device, data configuration is (2B1Q-ISDN) that needs.If need in 454 place's specified data configurations, then process advances to step 456, and in this step, DSP 120 carries out the 2B1Q pattern.If in 454 place's specified data configurations is unwanted, then process advances to step 458, in this step, DSP sends a piece of news to end-user device, and wait for the message that will receive and prepare to be analyzed, so that determine whether end-user device is the equipment of an ISDN type.If what determine at 458 places to carry out is the 2B1Q pattern, then process advances to step 456, with execution 2B1Q pattern.Leave step 456, processing procedure terminates in the 2B1Q pattern that step 456 starts, and when synchronization was failed, promptly when losing with the signal of communication of isdn device, process from then on step returned to 454 places.

If determining end-user device at 458 places is not an isdn device, and do not prepare to carry out 2B1Q, then process advances to step 460, in this step, DSP determines whether to exist one " RINGER (ringer) ", and promptly whether end-user device is a phone.By sending a signal and read echo signal, can realize this differentiation to end-user device.If determining end-user device at 460 places is a phone, then process advances to step 462, and in this step, DPS carries out pulse-code modulation (PCM) CODEC function.Leave step 462, execution is communicated by letter with phone, and until being taken back on the hook housing at step 463 phone, after this step, processing procedure returns to 454 places.

Fig. 7 has provided an explanation and has been applied to the block diagram of visiting an integrated SLIC in node or the line interface unit at 500 places.A service logic under the control of visit node can become to provide the ISDN service ISLIC circuit arrangement or POTS is provided service.A report mechanism at ISLIC can be told the CPU 116 of visit node the type of remote terminal.CPU 116 can provide needed network interface in real time.A map mechanism is set up, so that ISDN and POTS are served map to a single port.

Fig. 8 has provided a block diagram that the automatic exchange that is used for exchanging automatically between POTS and ISDN realizes at 530 places.An ISDN terminal 532 is coupled to loop and visit node controller switch by a line.ISLIC sends a series of 2B1Q synchronization codes, to trigger waking up isdn device 532.ISLIC notifies CPU116: the final terminal of ISDN is connected to end user's port.CPU checks the configuration that is allowed.Next, CPU controls ISLIC, to exchange to ISDN from POTS.

Fig. 9 has provided a block diagram that the function of automatic ISLIC that detects and xDSL terminal is described at 550 places.An xDSL terminal 552 is connected in a Line cards by a loop.ISLIC sends a series of xDSL synchronization codes, to trigger waking up xDSL terminal 552.116: one xDSL terminals 552 of ISLIC notice CPU are connected in a Line cards.Then, CPU checks the configuration that is allowed.Next, CPU makes ISLIC exchange to xDSL from POTS.CPU connects ATM or TDM bus according to concrete configuration.

Figure 10 A has provided a logic block-diagram at 570 places, explanation be the function that is applied to an ISLIC of the function that the data that have on the speech use according to the invention.Digital system 572 links to each other with a port of Line cards.A phone 574 also links to each other with the same port of Line cards by a filter 576.Circuit had both comprised the common voice signal from phone 574, also comprised the digital bandwidth signal.About 334khz, the digital bandwidth signal is between 4kHz and 160kHz or more than the 160kHz from the mandarin tone signal of phone.The circuit of the analog to digital of a high speed (A-D circuit) is connected to numerical data and the speech of DSP respectively.The numeral traffic enters system, and outputs to ATM or packet bus.The speech traffic enters the TDM bus.

Figure 10 B has provided a logic block-diagram of interface card 582 at 580 places, interface card 582 provides the CODEC function of having improved speech quality according to the invention.Card 582 has the port of a coupling, is used for providing 20Hz～loop of 20KHz speech bandwidth and communicating by letter of a music system 584 by one.Interface card 582 comprises: an integrated subscriber line interface circuit (ISLIC) 586; The ISLIC control unit 588 of a coupling is used for and the communicating by letter of ISLIC 586; And the signaling control unit 590 of a coupling, be used for and the communicating by letter of ISLIC 586.

ISLIC 586 comprises: a digital CODEC unit 591, and it provides selectable coding and decoding function with a kind of form selected in PCM and the CD-ROM form; The converter unit of the digital to analogy of a high speed (D/A unit) 592, it has the input port that an output port with CODEC unit 591 is coupled, an output port that is coupled by a node 593 and the port 583 that blocks, D/A unit 592 is used to provide the sample of per second more than 40000; And the converter unit of the analog to digital of a high speed (A/D unit) 594, it has an input port that is coupled by the output port of a node 593 and D/A unit 592, and the output port 595 of a coupling, so that a signal to be provided to CODEC unit 591, A/D unit 594 is used to provide the sample of per second more than 40000.

The voice signal of the inflow that one of high-speed a/d unit 593 sampling is received by the port 583 of music system 584, therefore, ISLIC 586 provides improved pcm encoder and improved speech quality.Numeral CODEC unit 591 can use a general standard code scheme (for example CD-ROM encoding scheme) to obtain the voice response of 20Hz～20KHz.The loop can be connected in the voice sources of a high-fidelity.ISLIC control unit 588 can provide the PCMCODEC function or the improved CODEC function of standard.ISLIC 586 also can use an automatic sensing circuit, is used to adjust end to end.

Figure 11 has provided the block diagram of another embodiment of Line cards according to the invention at 600 places.In described embodiment, Line cards comprise one and with the unit 604 of difference analog to digital and digital to analogy, this unit has a port 606, port 608, a control port 610 that is connected in the port 612 of DSP 120; An amplifying device 620, it has the input 624 of a coupling, to receive the voltage of negative 48V, the input 626 of a coupling, to receive the voltage of 110V, 628, one of the ports of a port 606 that is coupled in unit 604 by one 0.1 microfarad capacitor 630 are coupled in a port 632 of the port 608 of unit 604 by one the 2 0.1 microfarad capacitor 634; A port 636 that is coupled in node 642, a node 640 that is coupled in node 642,644, one of an input that are coupled in a node 646 is coupled in the 3rd input 648 of a node 650, and the 4th input 652 that is coupled in node 654.Node 642 is coupled in node 646 by one 65 ohm load, and node 650 is coupled in node 654 by one the 2 65 ohm load 660.Node 646 is coupled, to receive loop signals by port one 27.Node 650 is coupled, to receive terminal signal by port one 27.

Figure 12 has provided a block diagram at 700 places, explanation be the impedance filtering and the equilibrium function of Line cards of the present invention.Described embodiment comprises an impedance filter 702, in the embodiment that is recommended, impedance filter 702 is to use the software that can carry out on digital signal processor 120 to be realized, this filter has the input 704 of a coupling, to receive the signal from the A-D transducer.

Following relation (1) is for a self adaptation impedance model according to the invention provides an expression formula.

$Y=\underset{i=1}{\overset{i=n}{\mathrm{\Σ}}}\mathrm{Ai}*\mathrm{Xi}$

Different Ai provides different input impedance and output impedance.Therefore, can minimize to a minimum value between the both direction to a terminal balance return loss (TBRL) and a terminal balance loss (TBL).Filter step is n; Change n and can satisfy different required precisions.In general, the codomain of n is between 4 and 8.Described functional relation (1) is to use and can be obtained by the performed software of DSP.Therefore, can satisfy impedance requirements by adjusting impedance by the country variant prescribed by standard.

In described embodiment, A/D change-over circuit and D/A change-over circuit are to use ∑-Δ model to be realized.Because we have used ∑-Δ model, therefore numerous affairs can be handled by dsp software.

Therefore the inverse filter of A/D direction is very little, is easy to lower expense in addition integrated.In one embodiment, ISDN ' U ' is defined by 80k sample/13 bits.In one embodiment, the SLIC speech is defined by 20k sample/15 bits or 40k sample/14 bits.

Because the speed of sample is higher than 8khz, so be easy to obtain impedance.When it changes to ISDN ' U ' interface, 30 ohm of front-end circuit stuck-at-s.

For the D/A direction, ISDN ' U ' is 320k sample/8 bits, and the SLIC speech is 20k sample/13 bits.

In a word, as a PCM CODEC, Line cards provides: the voice data of 13 bits is encoded in an a-rule or a μ-rule pcm encoder; The equalization of logical digital filtering of band and voice signal; And the impedance matching function that can support 600 or 900 ohm.As an ISDN echo cancellation transceiver, Line cards provides: 2B1Q modulation and demodulation, dynamically suitable from answering speech to eliminate and automatic electric-level adjustment and control.At last, Line cards also provides the loop calibration function, and this function comprises that the loop that is provided by Digital Signal Processing software is balanced compensated.

Although abovely the present invention has been carried out concrete description by reference to specific embodiment, estimate any change of the present invention and modification, for those are familiar with the people of this technology, will be very easy understanding undoubtedly.Therefore, the present invention attempts following invention protection range is explained that these invention protection ranges will cover all change that does not deviate from the spirit and scope of the invention and modifications.

Claims (11)

1. adaptive user line interface that uses at the telecommunications network that is used for providing a series of telecommunications services, this interface system is used for providing an adaptive interface between the current a kind of equipment that connects of end-user device of node of network and series of different, the current end-user device that connects is applicable to that by the communication by the corresponding service that this network provided this interface circuit comprises:

The digital signal processor of a coupling is used for communicating by network;

The adaptive interface circuit of a coupling is used for and the communicating by letter of above-mentioned digital signal processor, and provides an adaptive interface between above-mentioned digital signal processor and the current end-user device that connects;

Memory cell is used for storage:

One first interface modes program is used to dispose above-mentioned digital signal processor, providing and one first relevant one the first group interface function of service,

One second interface modes program is used to dispose above-mentioned digital signal processor, providing and one second relevant one the second group interface function of service, and

A trace routine that is used to dispose above-mentioned digital signal processor, automatically determine the current end-user device that connect required corresponding service by above-mentioned adaptive interface circuit from the signal that the current end-user device that connects receives in order to basis, and

Above-mentioned adaptive interface circuit comprises: one 2 line is to the change-over circuit of 4 lines, if first service that the current end-user device needs that connect are above-mentioned, can run on one first service mode, if second service that the current end-user device needs that connect are above-mentioned also can run on one second service mode.

2. the adaptive user line interfacing system described in claim 1, wherein, the first above-mentioned service is a common old-fashioned telephone service (POTS), and the second above-mentioned service is an integrated services digital network service (ISDN service).

3. the adaptive user line interfacing system described in claim 1, wherein, the first above-mentioned service is a common old-fashioned telephone service (POTS), and the second above-mentioned service is a digital subscriber line service (DSL service).

4. the adaptive user line interfacing system described in claim 1, wherein, the first above-mentioned service is an integrated services digital network service (ISDN service), and above-mentioned second to serve be a digital subscriber line service (DSL service).

5. an adaptive user line interfacing system as being stated in the claim 1, wherein, above-mentioned adaptive interface circuit also comprises:

The transducer of a digital to analogy is used to receive the digital signal from above-mentioned digital signal processor, and is used for above-mentioned digital signal is converted to analog signal, and above-mentioned analog signal through conversion is submitted to above-mentioned change-over circuit; And

The transducer of an analog to digital is used to receive the analog signal from above-mentioned change-over circuit, and is used for above-mentioned analog signal conversion is become digital signal, and above-mentioned digital signal through conversion is submitted to above-mentioned digital signal processor.

6. the adaptive user line interfacing system described in claim 1, wherein, above-mentioned adaptive interface circuit also comprises the protective circuit of a coupling, is used for the communication with the above-mentioned current end-user device that is connected.

7. adaptive user line interfacing system that uses at the network that is used for providing a series of services, interface system is used for providing an adaptive interface between the current a kind of equipment that connects of the end-user device of network and series of different, the current equipment that connects is applicable to according to a corresponding communication for service, interface circuit comprises the digital signal processor of a coupling, is used for communicating by this network.The adaptive interface circuit of a coupling is used for and the communicating by letter of processor.This circuit provides an adaptive interface between processor and the current end-user device that connects.Processor can be carried out one first interface modes process, is used to provide and one first one first group interface function, one second interface modes process of execution that service is relevant, is used to provide and one second one the second group interface function that service is relevant.A testing process, in order to determine the required respective service of the current end-user device that connects, testing process comprises the following steps:

Send one first message to the current end-user device that connects;

Receive a signal from the current end-user device that connects; And

Analyze the above-mentioned signal that receives, with a corresponding service of in first and second services, determining to be applicable to that the current end-user device that is connected communicates.

8. at the adaptive user line interfacing system described in claim 7, the first above-mentioned service is a common old-fashioned telephone service (POTS), and the second above-mentioned service is an integrated services digital network service (ISDN service).

9. at the adaptive user line interfacing system described in claim 7, the first above-mentioned service is a common old-fashioned telephone service (POTS), and the second above-mentioned service is a digital subscriber line service (DSL service).

10. at the adaptive user line interfacing system described in claim 7, the first above-mentioned service is an integrated services digital network service (ISDN service), and the second above-mentioned service is a digital subscriber line service (DSL service).

11. also comprising the following steps: in as the adaptive user line interfacing system of being stated in the claim 8 then provides pulse-code modulation (PCM) CODEC function if determine that the current end-user device that connects is adapted to communicate by a common old-fashioned telephone service.

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