MXPA98005185A - Telephone verification equipment based on digita signal processor - Google Patents

Abstract

A verification equipment based on digital signal processor programmed to allow a technician to check and process signals of various formats that are present in a line under test, including analog signals type modem user characteristics. Such signals may include caller ID signals, visual message waiting indicator signals, and analog service interface signals. Through embedded duplicate echo cancellation routines, the DSP supervisor of the verification team is able to provide what is effectively dual address, full duplex, hands-free acoustic speaker phone functionality, which allows the field technician speak, while listening simultaneously to an acoustic output generated by the receiver of the verification equipment

Description

TELEPHONE VERIFICATION EQUIPMENT BASED ON DIGITAL SIGNAL PROCESSOR The present invention relates to communication systems and relates in particular to an operator verification equipment based on a digital signal processor, which is configured to provide a variety of signal processing characteristics, including the ability to perform telephone communications. of hands-free loudspeaker, full duplex, effectively in real time, and the processing of modem-type analog signals of user characteristics, such as, but not limited to, caller ID signals, visual message waiting indicator signals, and Analog interface signals of visualization services. The verification equipment also has the ability to measure the voltage in the hung position, the voltage in the off-hook position and the current conditions in the off-hook position of a telephone line. In addition, it can measure the response of the line to an applied electrical stimulus, to allow the verification team to detect the presence of an electrical discontinuity, such as a load coil that has been introduced into the line. For the purposes of checking and troubleshooting, telephone network field service personnel, or operators, have employed what are essentially reinforced versions of a standard telephone device. As such, the functional capabilities of these conventional verification equipment are not adequate to deal with a growing number of aspects of the telecommunications environment of today, including, but not limited to, special features, such as call waiting, ID of caller, and the use of POTS lines (old ordinary telephone service) to provide digital data services. Furthermore, since the acoustic interface of a conventional verification equipment is essentially a semi-duplex architecture, the ability of the field technician to use it "hands-free" can be severely limited, especially in an environment that has a lot of ambient noise, such as the inherent to the operation of industrial equipment and the flow of highway traffic. As a consequence, an improved verification equipment is needed, which retains the capabilities and physical characteristics of a conventional verification equipment (namely that it can verify POTS lines, and is relatively compact (hand-held) and physically and electrically resistant), but which, however, allows the operator to verify, receive and process signals of various formats that may be present in a line under test. In addition, the field staff has expressed the wish that their verification teams have a double-address, full-duplex, truly "hands-free" or speaker phone acoustic interface, namely, that which allows the field technician to speak (a distance) in the presence of background noise, while listening simultaneously to an acoustic output generated by the receiver of the verification equipment. The present invention includes verification equipment for testing and performing telecommunications link communications including a telecommunications link connection port through which the verification equipment can be connected to said telecommunications link, a user interface through the that an operator can input and receive information signals associated with the operation of said verification equipment, said user interface including a manual input device, visual screen, an audio interface through which said operator can input and receive acoustic signals , and a programmable digital signal processor unit, which includes signal format translation circuitry coupled to said telecommunications link connection port and said user interface, containing a signal processing routine that is operative to digitally process controllable signal those that have been received from said telecommunications link and have been digitally formatted by said signal format translation circuitry for supplying said user interface, and to controllably digitally process signals that have been received from said user interface and have been digitally formatted by said signal format translation circuitry to supply them in application to said telecommunications link connection port to apply them to said link of telecommunications. The invention also includes verification equipment for testing and performing telecommunications link communications including a telecommunications link connection port through which the verification equipment can be connected to said telecommunications link, a user interface through wherein said technician can input and receive information signals associated with the operation of said verification equipment, said user interface including a manual input device, visual screen, and an audio interface through which said technician can introduce and receiving acoustic signals, a programmable digital signal processing unit, which is operative to digitally process the signals generated by said audio interface in response to acoustic signals introduced by said technician, and signals received from said telecommunications link connection port to reproduce them as sign acoustics by means of said audio interface, in such a way as to provide total duplex generation in real time of acoustic signals by said audio interface for presentation to said technician at the same time that acoustic signals are being introduced in said audio interface by said technician, said The digital signal processor is operative to execute an echo cancellation routine that suppresses an echo of the acoustic signal that has been supplied from a remote end of said telecommunications link and has re-entered a microphone of the verification equipment from an output speaker of said audio interface, or is coupled to said telecommunications link as a result of impedance mismatches in one or more electrical interfaces of said telecommunications link. An object of the invention is an improved verification equipment based on digital signal processor, which is configured and is programmable to perform various signal processing functions, including, but not limited to, performing conventional verification equipment operations, providing communications of Total duplex speaker phone, effectively in real time, and the processing of analog signals type modem user characteristics. Such user characteristic signals may include caller ID signals, standby visual message indicator signals, and analog service interface signals of display services. The verification team based on digital signal processor (DSP) of the present invention also has the ability to measure electrical conditions (the voltage in hanging and off-hook position, and the current in off-hook position) of a telephone line. It can measure the response of the line to an electrical stimulus, to allow the verification team to detect the presence of an electrical discontinuity, such as a load coil, which has been introduced into the line. The signal processing architecture of the digital signal processor-based verification equipment of the present invention preferably includes a telecommunications link connection port, through which the verification equipment can be connected to (tip and loop conductors) of a standard bifilar pair POTS subscriber line. A tip / hoop interface, which serves as a POTS loop current load, couples audio signals (voice, call signal, tone) to and from the POTS line connection, and allows to derive loop power from the POTS line for a internal loop power supply to operate the circuitry of the verification equipment. The incoming voice and tone signals from the POTS line are digitized by an associated line codee and coupled to a digital control and supervision signal processor (DSP), which is programmed to process signals received from the line and which have been formatted digitally by the line codee to supply them to a user interface (input / output unit). The DSP also serves to process inputs from the user interface unit to apply them to the line. The outgoing signals to be transmitted over the network, supplied by the DSP, are converted to analog format by the line code and applied to the line through the tip / hoop interface. A verification mode circuit is coupled to the line connection port so that the line can check the presence of audio signaling without having to go off-hook. A data detector is coupled to the line connection port to determine if there are data signals on the line, and thus prevent the verification equipment from going off-hook and corrupting a data signal, if in fact a signal was detected. data on the line. The user interface unit allows the technician to input and receive information signals associated with the operation of the verification equipment, or to enter and receive voice signals during full duplex communications with another party coupled to the line. For this purpose, the user interface includes a numeric keypad, a visual LCD screen, and an audio interface through which the technician can listen and vocalize acoustic signals to the verification team. The audio interface is coupled to the processor by means of a codee associated with audio. To provide double-sided, full-duplex, effectively real-time communications, allowing the field technician to speak (from a position within the sensitivity band of the verification team), while simultaneously listening for an acoustic output generated by the Verification equipment receiver, the verification equipment processor is programmed to execute an echo cancellation routine which suppresses a replica or echo of the acoustic signal that has been supplied from the remote end of the line and has re-entered into the microphone of the Verification equipment from its output speaker, or is coupled to the line as a result of impedance mismatches at the electrical interfaces. To accommodate signals simultaneously supplied from each end of the network, the echo cancellation routine contains a pair of complementary or "duplicate" echo cancellation software modules. A line echo cancellation module (network) processes signals in the signal paths with the line interface and is operational to prevent audio signals from the "near end" introduced from the microphone of the verification equipment are injected as electrical echoes to the audio signals transferred from the speaker. An acoustic echo cancellation module processes signals in the signal paths of the microphone and loudspeaker of the verification equipment and is operative to prevent audio signals from the "remote end" of the network being injected as acoustic echoes of feedback to the audio signals sent to the network. The full-duplex speaker phone processing routine is initialized in half-duplex mode, allowing audio signals to be transmitted only in one direction at that time. Any audio signal that has the highest signal level will control the signal path to be suppressed. During this initial semiduplex conversation between the technician and the remote end of the network, each of the echo cancellation modules trains an associated echo model. When the line and acoustic echo models are trained, the amount of gain reduction of the signal path with original gain suppression will be decreased, until the processing routine eventually arrives at what is effectively a full duplex mode of operation. The echo patterns are continuously adjusted during the additional processing of the audio signals. If the performance of the echo canceller degrades below a threshold that effectively prevents simultaneous audio communications, the routine returns to half-duplex mode, in which the gain of a respective signal path is controlled by the audio level, as in initialization mode. Then, when the echo models are retrained, the processing routine comes back to full duplex mode. In addition to providing full-duplex, real-time voice communications, the verification equipment of the present invention is operative to process modem analog signals of user characteristics, including caller ID signals (caller id), message indicator signals. visual standby (VMWI), and analog services display interface (ADSI) signals, each of which is usually transported using standard modem-based signaling at 1200 bits per second (BPS) (Bell 202 standard). For processing the caller ID, the verification equipment is hung up. When a call signal is received from the central office, the processor of the verification equipment is operative to extract and demodulate the caller ID information that is transmitted in the quiescent interval between the first and second bursts of call signal tone. This caller ID information is then displayed to the technician via the LCD screen of the user interface of the verification equipment. For the processing of ADSI signals, the technician makes a DTMF call to an ADSI server. When ADSI signals are received from the server in response to a request from the verification equipment containing the feature access code (via DTMF signaling), a tampering signal (CAS) will be received from the customer's facility equipment (CPE) of the server accessed, warning the verification team of an incoming modem signal of caller information. The DSP of the verification equipment then sends again a DTMF recognition sequence to the ADSI server. The audio to the headset and speaker of the verification equipment is muted, so that the next incoming modem burst from the ADSI server is not heard by the technician. Once the ADSI information has been transmitted and received by the verification team, the DSP of the verification team sends a DTMF recognition sequence back to the ADSI server, recognizing the received ADSI information. The ADSI information is then demodulated to present it to the technician via the LCD screen of the user interface of the verification equipment, and the silencing of the audio output to the headset and loudspeaker is terminated. The processing of VMWI signals is similar to the call waiting, caller ID, except that voice message data is transmitted without any type of trigger signal (for example, call signal). For Caller ID / 11 waiting call, in response to reception of a CAS signal from the central office, the DSP of the verification team sends a DTMF recognition sequence back to the central office, as in the case of ADSI signals. Then the audio output to the headset and speaker is muted, to prevent the modem burst from being heard by the technician. Then, the data transmitted to the verification equipment is demodulated to be presented to the technician via the LCD screen of the user interface of the verification equipment, and the silencing of the audio output to the headset and loudspeaker is removed. The DSP-based verification equipment of the present invention also has the ability to perform additional line measurements, including measuring line voltage in hanging position and in off-hook position and current conditions in off-hook position of a line of phone. In addition, it can measure the response of the line to an electrical stimulus, to allow the verification team to detect the presence of an electrical discontinuity, such as a load coil, introduced into the line. For load coil measurements, a sweep frequency signal is applied to the line through a known impedance, and the resulting AC voltage is measured across the tip and loop conductors. In particular, the amplitude and phase variation of the AC voltage versus the frequency is measured. Since it is based on DSP, the verification equipment of the invention can also check and visualize signal traffic, such as the caller ID, VMWI and ADSI, between a server and a subscriber terminal. In this mode of operation, the verification team can analyze and visualize the quality of the caller ID signal, VMWI and ADSI traffic from a server (with the operational verification equipment as a terminal device), from the server with the terminal of subscriber, or from the equipment of the client's facilities. The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 illustrates diagrammatically the architecture of a verification equipment based on digital signal processor. Figure 2 illustrates diagrammatically an echo cancellation signal processing module. Figure 3 illustrates diagrammatically a total duplex echo cancellation signal processing routine employed by the digital signal processor of the verification equipment of Figure 1 to process signals simultaneously supplied locally and from a remote end of the network.

Figure 4 depicts a caller ID signal processing routine. Figure 5 represents an ADSI signal processing routine. Figure 6 depicts a caller ID / call waiting treatment routine. And Figure 7 represents a VMWI signal processing routine. Figure 1 illustrates diagrammatically the signal processing architecture of a digital signal processor (DSP) based verification equipment of the present invention including a telecommunications link connection port 10, through which the verification equipment can be connected with tip and ring conductors 21 and 22 of a POTS line of standard bifilar pair 20. Coupled to port 10 there is a standard rip / rim interface (T / R) 30, which serves as a POTS buzzer current load, and provides an audio signal path (voice, call signal, tone) to and from the POTS line connection on port 10. The T / R 30 interface also serves to derive power from loop for an internal conventional loop power supply (not shown) to operate the circuitry of the verification equipment. The incoming signals received from the line by the T / R interface 30 are digitized by a codee associated with line 40 and coupled to a digital signal processor (DSP) 50, which supervises and controls all operations of the verification team. The outgoing signals to be transmitted over the network, supplied in digital format by the digital signal processor 50, are converted to analog format by the codec 40 and applied to the T / R interface 30. As a non-limiting example, the DSP 50 can include a commercially available, low cost, low power, high performance DSP chip, such as one selected from the commercially known as the TMS320C chip equipment (e.g., digital signal processor chips of the TMS320C2xx or TMS320C5x type) manufactured by Texas Instruments , Inc., United States of America. The availability of such high performance DSP components not only makes it possible for the processor to execute the signal processing functionality of each of a plurality of what have ordinarily been discrete communication components, but also allows to execute signal processing algorithms. relatively sophisticated, such as bidirectional echo cancellation, to be described, in real time and in real time, thereby providing total duplex communication capability "hands-free" in a relatively compact device. The digital signal processor 50 is programmed to process signals received from the line and digitally formatted by the codec 40 to be sent to a user interface or input / output unit, represented in dashed lines 100. The DSP of the verification equipment it also serves to process user interface entries to apply them to the line. Additional operations of the standard digital processor include scanning the numeric keypad 110 of the user interface, sending characters to a visual LCD screen 120 for presentation, controlling the on / off status of the T / R 30 interface, and controlling the status of a loudspeaker amplifier 180. A high impedance check mode circuit 60 is coupled AC to the connection port tip / hoop 10 and has its output coupled to the processor 50 so that the verification team can check on the line the presence of audio signaling without having to go off hook. A data detector circuit 70, which may be of the type described in the specification of US Pat. No. 4,939,765, is also coupled to the line connection port 10, and provides an output indicative of whether there are data signals. on line 20. This output is used to controllably prevent the verification equipment from going off-hook and thereby corrupting a data signal, if in fact a data signal was detected on the line. The user interface 100 is the mechanism through which the technician can input and receive information signals associated with the operation of the verification equipment, or supply and receive voice signals in the course of full duplex communications with another party coupled to the line. The user interface 100 includes the numeric keypad 110 composed of a standard set of alphanumeric and auxiliary function keys, a visual LCD screen 120, and an audio interface 130 through which the technician can receive (listen) and input (voice ) acoustic signals in relation to the verification equipment. The audio interface 130 is coupled to the digital signal processor 50 by means of a codee associated with audio 140. Like the codee associated with line 40, the codee associated with audio 140 is operative to digitize audio (voice) signals spoken to a microphone of the verification equipment 150 to apply them to the processor 50. Conversely, the incoming signals received from the network (at the line connection port 10), which have been digitized by the codec 40 and processed by the processor 50, are converted to analog format by the codec 140, and applied to a headset of the verification equipment (receiver) 160, and to a loudspeaker 170 by means of a loudspeaker amplifier 180. The digital signal processor 50 is programmed to process signals that have been received from various inputs of the verification team and digitally formatted by an associated code. Once processed, the signals are formatted appropriately by a codec and sent to its intended output port. The manner in which these signals are processed and the supervisory control routine executed by the digital signal processor supervisor of the verification equipment for the various communication and control operations of the verification equipment architecture. The double duplex total address loudspeaker telephone means an acoustic signal interface that allows the field technician to speak (from a close position within the sensitivity band of the verification equipment), while also simultaneously listening (effectively in real time) an acoustic output generated by the receiver of the verification equipment. This differs from conventional semiconductor speaker phone architectures, which are operative to allow only unidirectional audio transmission at any instant in time. The digital signal processor 50 employs an echo cancellation routine that effectively suppresses replication or echo of the acoustic signal that has been supplied from the remote end of the line and re-enters the microphone of the verification equipment from its output speaker , or it is coupled to the line as a result of impedance mismatches at the electrical interfaces. Namely, the echo cancellation routine executed by the DSP of the verification equipment is effective to remove the signal echo from the remote end of the near-end signal path, so that only the near-end signal (i.e. locally provided by the technician) is retransmitted to the remote end. The signal processing functionality of this echo cancellation signal processing routine is illustrated diagrammatically in FIG. 2, which represents three communication signals that are potentially present in the channel. The first signal is the signal from the remote end, represented as supplied at a remote end 201 of the network, and which is (acoustically) reproduced in a near-end output port 205 (for example, by the output speaker of the equipment of verification 170). The second signal is the signal from the near end 207, which is supplied locally (for example, by the operator speaking to the microphone of the verification equipment 150). A third signal is the echo or replica 211 of the acoustic signal that has been supplied from the remote end of the line and has reentered the microphone of the verification equipment from its output speaker, or is coupled to the line as a result of mismatches of impedance in the electrical interfaces. In addition to these actual signals that may be present at any time, the signal processing routine generates a fourth echo cancellation control signal, which is a model 213 of the source of the echo signal 211. The signal pattern of echo 213 is differentially combined in a differential operator 215 with the near-end signal (which includes all echo 211 of the remote end signal 201 that may be present) and the resulting signal 217-in the absence of the signal components of unwanted echo-is transmitted to the remote end of the network. When a signal from the remote end 201 is present, but no signal from the near end 207 is present, any apparent signal from the near end is necessarily an echo and has to be suppressed. In this case, the echo signal pattern 213 is regulated by a software supplied control input 215, until the near end signal 207 is effectively zero. The period of time required to eliminate the echo signal 211 (here due to feedback of the remote end signal as a near end signal) is typically referred to as the convergence time. Since the loudspeaker telephone processing routine must accommodate signals simultaneously supplied from each end of the network, respective "duplicate" representations of the echo cancellation routine of Figure 2 are combined in a total duplex echo cancellation routine illustrated diagrammatically in Figure 3. As depicted there, in the network or tip / hoop interface (T / R) 30, there are audio signals 301 coming from the network 20 and audio signals 303 coming out to the network. In a complementary manner, in the acoustic interface of the verification equipment 130, there are audio signals 311 that enter through the microphone of the verification equipment 150 and audio signals 313 that exit the loudspeaker 170. The processor is programmed to execute a signal processing routine for echo cancellation of line (network) 320, which processes signals in the signal paths with the T / R interface 30 and is operative to prevent audio signals from the "near end" 311 introduced by the microphone of the verification equipment 150 being injected as electrical echoes to the audio signals 313 outputs of the loudspeaker 170. The line echo cancellation routine (network) 320 may include a network echo cancellation processing software module, marketed, such as a "Canceling module" module. low complexity network echo, "from D2 Technologies, Inc., Santa Barbara, California, United States of America. In the opposite direction, the processor executes an acoustic echo cancellation routine 340 which is operative to process signals in the microphone 150 and loudspeaker 170 of the signal paths and to prevent the audio signals from the "remote end" 301 inputs from the network 20 are injected as acoustic feedback echoes to the audio signals 303 outputs to the network. Like the network echo cancellation routine 320, the acoustic echo cancellation routine 340 may include a commercially available echo cancellation software module, such as an "Acoustic echo canceling, hands-free (for TMS320C5x) module. "by France Telecom CNET, Marzin, France, or a module" IDEC ™ -II Acoustic echo cancellation, hands-free for TMS320C3x / 'C4x ", by DSP Software Engineering, Inc., Bedford, Mass., United States of America. In operation, the combined total duplex loudspeaker telephone processing routine that contains each of the line and acoustic echo cancellers is initially in a half-duplex mode, allowing audio signals to be transmitted in only one direction at that time. For this purpose, the routine uses any audio signal that has the highest signal level to dictate the path to be deleted. If the transmission path has a higher audio level, then the gain of the reception path is reduced. Conversely, if the reception path has a higher audio level, then the gain of the transmission path is reduced. During the initial semiduplex conversation between the technician and the remote end, each of the duplicate echo cancellation routines 320 and 340 will adaptively train or adjust their respective echo mode. When the respective echo patterns are trained, the amount of reduced gain of the reduced signal path will be decreased, until the processing routine eventually arrives at a fully duplex operating mode. The echo patterns are adjusted continuously during the additional processing of the audio signals. If the performance of the echo canceller degrades below a preset threshold that effectively prevents simultaneous audio communications, the routine returns to half-duplex mode, in which the gain of a respective signal path is controlled by the audio level, as shown in FIG. described above. Then, as the echo patterns are retrained, the processing routine comes back to full duplex mode. This closed-loop adjustment process is repeated as necessary to maintain optimum performance. Verification equipment based on digital signal processor is operative to process analog signals modem type of user characteristics, including caller ID signals (caller ID), caller ID signals / 11 waiting call, visual message indicator signals Standby (VMWI), and analog services display interface (ADSI) signals, each of which is usually transported using a modem-based signaling of 1200 bits per second (BPS) (Bell 202 standard). The communication control routine resident within the DSP 50 is operative to demodulate this modem signal, and to detect an alteration signal (CAS) from the equipment of the client's facilities.

(CPE), which is used for caller ID / call waiting and ADSI signals, as a precursor signal that indicates which modem data is being sent. The processor recognizes a CAS signal by returning a preset DTMF sequence. The communication control and monitoring routines executed by the DSP 50 for each of these modem analog signals of user characteristics will be described below with reference to the flow diagrams of Figs. 4-6. As in the case of echo cancellation routines, the DSP 50 may employ commercialized communications processing software modules to process analog modem signals of user characteristics. As a non-limiting example, the DSP 50 can employ the "ADSI" algorithm module obtainable from D2 Technologies, which is operative to detect CAS tone signals, generate DTMF signals for recognition and marking, detect and decode data signals from 1200 baud FSK modem, detect call processing tones in the presence of voice signals, and generate 1200 baud FSK modem signals for extended ADSI requirements. Before processing an incoming call, the verification equipment is in the hung state, as represented in step 401. In step 403, a call signal is received from the central office, warning the verification team of a call incoming. In step 405, the caller ID information that is transmitted in the interval (quiescent four seconds) between the first and second bursts (one second activated - four seconds off) of ring tone. In step 407, the received caller ID information is demodulated and displayed to the technician via the LCD screen 120 of the user interface 100 of the verification equipment. As the ADSI signals are received in response to a request from the verification equipment, the verification equipment will be in off-hook status, as represented in step 501, making a call containing the feature access code (via DTMF signaling) to the ADSI server. In step 503, a CAS signal is received from the accessed server, warning the verification equipment of an incoming modem signal of caller information. In step 505, the DSP 50 again sends a DTMF recognition sequence to the ADSI server. In step 507, the audio to the headset 160 and loudspeaker amplifier 180 is muted, so that the next modem burst of the ADSI server will not be heard by the technician. Next, in step 509, the ADSI information is transmitted to the verification equipment from the server. In step 511, the DSP 50 again sends a DTMF recognition sequence to the ADSI server, recognizing the ADSI information received in step 509. This information is then demodulated in step 513 for presentation to the technician via the LCD screen 120 of the user interface 100 of the verification equipment. Finally, in step 515, the muting of the audio output to the headset 160 and loudspeaker amplifier 180 is removed, so that the verification equipment can return to its previous state. For id of the call waiting / waiting lover, in response to receiving, in an off-hook status, a CAS signal from the central office (step 601), the verification equipment DSP resends a DTMF acknowledgment sequence (step 603) , as in the case of ADSI signals. In step 605, it mutes the audio output to the headset 160 and loudspeaker amplifier 180, to prevent the modem burst from being heard by the technician. Then, the data transmitted to the verification equipment is demodulated (step 607) for presentation to the technician via the LCD screen 120 of the user interface 100. The muting of the audio output to the handset and loudspeaker is removed in step 609. VMWI signal processing is similar to call waiting, caller ID, except that there is no trigger signal before data transmission. Since it is based on DSP, the verification team has the ability to perform a number of auxiliary line measurements, which include measuring the line voltage in hanging position and in off-hook position and current conditions in off-hook position, as well as signal analysis functions third part. For this purpose, standard filtering analysis mechanisms can be used, such as Goertzel signal analysis algorithms, by digitizing the parameter that is checked and then coupling it to the processor's memory for analysis. For DC voltage measurements in hanging position, voltage (including polarity) is verified through the T / R 20 cables. For off-hook measurements, both the DC voltage (including polarity) and the DC current are checked through the T / R cables 20. For AC measurements in hanging / off-hook position, such as can be used to detect the presence of a discontinuity, such as a load coil, a sweep frequency signal is applied to the line through a known impedance, and the resulting AC voltage is measured through the tip and loop wires. The programmability of the verification equipment of the invention also allows to check and display third-party signal traffic, such as caller ID, VMWI and ADSI, between a server and a subscriber terminal. In this mode of operation, the verification team can analyze and visualize the quality of the caller ID signal, VMWI and ADSI traffic from a server (with the operational verification equipment as a terminal device), from the server with the terminal of subscriber, or from the equipment of the client's facilities. The user characteristic signals may include caller ID signals, standby visual message indicator signals, and analog service interface signals. In addition, through duplicate embedded echo cancellation routines, the verification team's DSP is able to provide what is effectively dual-address, full-duplex, hands-free acoustic speaker phone functionality, which allows the technician field to speak, while listening simultaneously to an acoustic output generated by the receiver of the verification team.

A verification equipment based on digital signal processor is programmed so that a technician can check and process signals of various formats that are present in a line under test, including analog signals type modem of user characteristics. Such signals may include caller ID signals, visual message waiting indicator signals, and analog service interface signals. Through duplicate embedded echo cancellation routines, the verification team's DSP is able to provide what is effectively dual-address, full-duplex, hands-free acoustic speaker phone functionality, which allows the field technician speak, while listening simultaneously to an acoustic output generated by the receiver of the verification team.

Claims (11)

1. CLAIMS 1. A verification equipment to check and perform telecommunications link communications including a telecommunications link connection port through which the verification equipment can be connected to said telecommunications link, a user interface through the that an operator can input and receive information signals associated with the operation of said verification equipment, said user interface including a manual input device, visual screen, an audio interface through which an operator can input and receive acoustic signals , and a programmable digital signal processing unit, including signal format translation circuitry coupled to said telecommunications link connection port and said user interface and containing a signal processing routine that is operable to digitally process controllable way signals that have been rec ibides of said telecommunications link and have been digitally formatted by said signal format translation circuitry to supply them to said user interface, and to digitally controllably control signals that have been received from said user interface and have been digitally formatted by said signal format translation circuitry for supplying them in application to said telecommunications link connection port for application to said telecommunications link.
2. 2. A verification equipment as claimed in claim 1, wherein said signal processing routine contained in said programmable digital signal processing unit is operative to process signals generated by said audio interface in response to acoustic signals input by said operator, and signals received from said telecommunications link connection port to reproduce them as acoustic signals by means of said audio interface, in such a way as to provide real-time full-duplex generation of acoustic signals by said audio interface to present them to said operator at the same time that acoustic signals are being input into said audio interface, said signal processing routine contained in said programmable digital signal processing unit is operative to process modem analog signals of preset user characteristics received from said telecommunications link p or said telecommunications link connection port to present the information contained in said modem analog signals of user characteristics pre-established to said technician by means of said user interface.
3. 3. A verification equipment as claimed in claim 2, wherein said modem analog signals of preset user characteristics include at least one of caller ID signals, visual message waiting indicator signals, analog service interface signals. display, said signal processing routine being contained in said operating programmable digital signal processing unit for causing a pre-established electrical stimulus to be applied to said telecommunications link and for measuring the response of said telecommunications link to said preset electrical stimulus, wherein said signal processing routine contained in said programmable digital signal processing unit is operative to detect the presence of an electrical discontinuity provided by a load coil in said telecommunication link according to said measured response to said stimulus the ctrico preset.
4. A verification equipment as claimed in any one of claims 1 to 3, including a data detector coupled to said telecommunications link connection port and which is operative to provide an output indicative of whether there are data signals in a telecommunications link to which said telecommunications link connection port is connected, said signal processing routine contained in said programmable digital signal processor unit is operative to allow or controllably prevent said verification equipment from going off-hook depending on the output provided by said data detector, also including a circuit of mode of verification coupled to said telecommunications link connection port and that is operative to check on said telecommunications link the presence of audio signaling, while said verification equipment is hung.
5. A verification equipment as claimed in any one of claims 1 to 4, wherein said signal format translation circuitry includes a codee associated with a telecommunications link that is operable to digitize speech and tone signals from said signal link. telecommunications to apply them to said digital signal processor, to convert the digital signals coming from said processor to analog format to apply them to said telecommunications link, a codee associated with audio interface that is operative to digitize voice signals introduced in said audio interface for apply them to said digital signal processor, to convert digital signals from said digital signal processor to analog voice format to apply them to said audio interface, wherein said user interface includes a numeric keypad, a visual screen, and an interface audio through which the The technician can listen and vocalize acoustic signals to the verification team.
6. A verification equipment as claimed in any of claims 2 to 5, wherein said digital signal processor is operative to execute an echo cancellation routine that suppresses an echo of the acoustic signal that has been supplied from a remote end of said telecommunications link and has reentered a microphone of the verification equipment from an output speaker of said audio interface, or is coupled to said telecommunications link as a result of impedance mismatches in one or more electrical interfaces of said link of telecommunications, said echo cancellation routine contains a pair of complementary echo cancellation operators, of which the first is operative to process signals in signal paths with said telecommunications link connection port and is operative to avoid signals Near end audio input from said microphone is injected as eléque echoes ctricos to audio signals outputs from said speaker, and from which the second is operative to process signals in signal paths of said microphone and said loudspeaker and prevents remote end audio signals coming from the telecommunications link to be injected as acoustic echoes of feedback to audio signals applied to said telecommunications link.
7. A verification equipment as claimed in claim 6, wherein said full-duplex loudspeaker telephone processing routine is initialized in a half-duplex mode, allowing audio signals to be transmitted only in one direction in time, controlling any signal audio having a signal level higher than the signal path to be suppressed, said loudspeaker telephone processing routine is operative to increase the gain of the signal path initially suppressed when the echo patterns associated with respective operators of said call cancellation operators first and second echoes are adjusted adaptively, until said loudspeaker telephone processing routine arrives at what is effectively a full duplex mode of operation.
8. 8. A verification equipment to verify and perform telecommunications link communications including a telecommunications link connection port through which the verification equipment can be connected to said telecommunications link, a user interface through which said technician can enter and receive information signals associated with the operation of said verification equipment, said user interface including a manual input device, visual screen, and an audio interface through wherein said technician can input and receive acoustic signals, a programmable dal signal processing unit, which is operative to dally process the signals generated by said audio interface in response to acoustic signals introduced by said technician, and signals received from said connection port of telecommunications link to reproduce them as acoustic signals by means of said audio interface, in such a way that it provides the total duplex generation, in real time, of acoustic signals by said audio interface to present them to said technician at the same time that signals are being introduced acoustic in said audio interface by said technician, said dal signal processor is operative to execute an echo cancellation routine that suppresses an echo of the acoustic signal that has been supplied from a remote end of said telecommunications link and has re-entered into a microphone of the verification equipment from an output speaker of said audio interface, or is coupled to said telecommunications link as a result of impedance mismatches in one or more electrical interfaces of said telecommunications link.
9. 9. A verification equipment as claimed in claim 8, wherein said echo cancellation routine contains a pair of complementary echo cancellation operators, of which the first is operative to process signals in signal paths with said port of echo. telecommunications link connection and is operative to prevent audio signals from the near end input from said microphone being injected as electrical echoes to audio signals outputs from said loudspeaker, of which the second is operative to process signals in signal paths of said microphone and said loudspeaker and prevents remote end audio signals from the telecommunications link being injected as acoustic feedback echoes to audio signals applied to said telecommunications link, said full duplex loudspeaker telephone processing routine being initialized in a half-duplex mode, enabling that the audio signals are transmitted in only one direction at that time, by controlling any audio signal having a higher signal level the signal path to be suppressed, said loudspeaker telephone processing routine is operative to increase the gain of the signal path initially suppressed when the echo patterns associated with the respective ones of said first and second echo cancellation operators are adjusted adaptively, until said loudspeaker telephone processing routine arrives at what is effectively a full duplex mode of operation.
10. 10. A verification equipment as claimed in claim 8 or 9, wherein said signal processing routine contained in said programmable dal signal processing unit is operative to process modem analog signals of preset user characteristics received from said link. telecommunications by said telecommunications link connection port to present the information contained in said modem analog signals of user characteristics pre-established to said technician by means of said user interface in which said modem analog signals of preset user characteristics include at least one of the caller identification signals, visual waiting message indicator signals, and analog services visualization interface signals.
11. 11. A verification equipment as claimed in claims 8, 9, or 10, including a code associated with a telecommunications link that is operable to dize speech and tone signals from said telecommunications link to be applied to said signal processor dal, and for converting digital signals from said processor to analog format to apply them to said telecommunications link, and a codee associated with audio interface that is operative to digitize speech signals introduced in said audio interface to apply them to said digital signal processor, and to convert digital signals from said digital signal processor to analog voice format to apply them to said audio interface.