Abstract:
A method for a telephone dialing apparatus to deliver a message to a customer premise is described. The method includes the steps of: initiating a telephone call by dialing a telephone number; enabling the apparatus to receive an off-hook signal; enabling the apparatus to detect a first tone if the off hook signal is received; enabling the apparatus to detect a second tone if the first tone is detected; terminating the call if the second tone is detected and transmitting the message to the customer premise if the second tone is not detected.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Provisional Application No. 60/527,055 filed Dec. 4, 2003, entitled “Phone Zapper Detection Technique”, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention is a message deliver system and more particularly, is a computerized telephone dialer that recognizes and defeats the action of devices designed to fool computerized telephone dialers into believing that a phone call can not be completed. 
     Predictive dialers (PDs) are computerized telephone dialers used by telemarketers to place, at a rapid rate, telephone calls to customer premises. The PDs sort through all the placed calls to find the few that are actually answered by a person. When a call is found that is answered by a person, the call is quickly transferred to a live telemarketing agent. 
     Predictive dialers sort the placed calls by monitoring the progress of each call and take action based on what happens when the called telephone is answered, i.e. goes off-hook. A chart of typical PD actions is shown in Table 1 below: 
     
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Event 
                 PD Action 
               
               
                   
               
             
             
               
                 Busy Tone 
                 PD hangs up 
               
               
                 Disconnect tone (Special 
                 PD hangs up. If an SIT is found on repeated 
               
               
                 Information Tone - SIT) 
                 calls, the telephone number is deleted from the 
               
               
                   
                 call list. 
               
               
                 No answer 
                 PD hangs up 
               
               
                 Answering machine 
                 PD hangs up 
               
               
                 Live answer 
                 PD searches for a live agent. If one is available, 
               
               
                   
                 the call is switched to an agent. If none is 
               
               
                   
                 available within a predetermined time, the PD 
               
               
                   
                 hangs up. 
               
               
                   
               
             
          
         
       
     
     Devices for defeating predictive dialers have been introduced into the marketplace. These devices, called colloquially, “zappers” or “zapping devices”, are connected to a customer&#39;s telephone line at the customer&#39;s premises. Zapping devices disconnect a calling predictive dialer from the called telephone number by placing a signal on the telephone line that appears to the predictive dialer to be a type of Special Information tone (SIT) signal. Such signals are used by United States telephone companies to signal ineffective call attempts. 
     Each type of SIT signal is characterized by a unique three tone sequence. A particular SIT, used generally by zapping devices for defeating a predictive dialer, is the operator intercept (OI) sequence consisting of a first tone at 913.8 Hz., a second tone at 1370.6 Hz. and a third tone 1776.7 Hz. Zapping devices generally operate by detecting when the called telephone is taken off hook and thereafter generating the first tone of the OI sequence, thereby deceiving a typical predictive dialer into believing that the called telephone number is not in service. In response, the predictive dialer releases the telephone line before a message from the predictive dialer is transmitted to the called telephone number. Generally, it is necessary for the zapping device to generate only the first tone of the OI sequence to defeat a PD, since a PD, in the interest of conserving time, determines that a full SIT signal has been generated with the detection of the first tone. 
     There are computerized telephone calls which need to be completed despite the existence of a zapping device on the telephone line of the number being called. Such calls include appointment reminder calls from, for instance, a physicians office, or public emergency notification calls. Accordingly, there is a need for a telephone dialers, that can distinguish the signal generated by the zapping device from a true SIT signal in order to deliver a desired message to the called telephone member. Further, the desired message needs to be deliverable by the telephone dialer whenever the telephone is answered, whether by a human or by a machine such as an answering machine, a facsimile or a modem. 
     Prior solutions for defeating the result of an emergency or appointment call being “zapped” require a human to place a follow up telephone call to the called telephone number in order to determine if the telephone number that was zapped was actually not in service. A preferred solution to the problem would provide the means for automatically distinguishing the tones generated by the zapping device from the tones of an actual SIT. 
     BRIEF SUMMARY OF THE INVENTION 
     A method for a telephone dialing apparatus to deliver a message to a customer premises, comprises the steps of: initiating a call by dialing a telephone number; enabling the apparatus to receive an off-hook signal; enabling the apparatus to detect a first tone if the off hook signal is received; enabling the apparatus to detect a second tone if the first tone is detected; terminating the call if the second tone is detected; and transmitting the message to the customer&#39;s premise if the second tone is not detected. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
       In the drawings: 
         FIG. 1  is a functional block diagram of a telephone dialer connected to public switched telephone network; and 
         FIG. 2  is a flow diagram showing steps for delivering a message to a customer premise in accordance with a preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings, wherein like numerals are used to indicate like elements throughout the several figures and the use of the indefinite article “a” may indicate a quantity of one or more than one, of an element, there is shown in  FIG. 1  a functional block diagram of a preferred embodiment of a telephone dialer  10  shown connected to a public switched telephone network (PSTN)  20  to which is connected at a customer premise, a telephone  30  and a zapper device  40 . 
     In the preferred embodiment, the telephone dialer  10  comprises a personal computer  12  in which a special purpose telephony/voice board  14  installed. The personal computer  12  also includes volatile and non-volatile memory and input/output devices such as a video display, keyboard and mouse. Preferably, the personal computer uses a Pentium® processor as a central processing unit and runs one of the Windows® operating systems. Such computers are manufactured by IBM corporation, Hewlett Packard corporation and Dell corporation. While it is preferred that personal computer  12  uses a Pentium® processor and runs under the Windows® operating system, the invention is not limited to any particular type of computer or any particular operating system. 
     Preferably, the telephony/voice board  14  includes a digital signal processor, volatile and non-volatile memory and means for electrically interconnecting the telephony/voice board  14  with a personal computer  12 . The telephony/voice board  14  is programmed to generate and detect dual tone multiple frequency (DTMF) and multiple frequency (MF) tones, used by the PSTN  20  for signaling. The telephony/voice board  14  can also be programmed to generate and detect application specific single and dual tones. The telephony/voice board  14  also: (1) transmits an off hook signal to the telephone line, (2) dials out, and (3) monitors and reports results to the personal computer  12  of line busy or congested, operator intercept, ring, no answer, or if the phone is answered, whether the phone is answered by a person, an answer machine, a modem, or a facsimile machine. Preferably, the telephony/voice board  14  is an Intel® Dialogic® Telephony Board Model Proline/2V, which includes all the foregoing features. As would be clear to one skilled in the art, the present invention is not limited to any particular telephony/voice board  14  as the implementation of such features as found in the Proline/2V are well known to those of ordinary skill in the art. 
     Referring now to  FIG. 2 , there is shown a method of delivering a message to a customer premises in accordance with the preferred embodiment. 
     In the preferred embodiment, the personal computer  12  includes within it, a database of telephone numbers to be called, and pointers to messages corresponding to the telephone numbers, recorded in the non-volatile memory of the personal computer  12  to be delivered to each telephone number. At step  102 , a program in the personal computer  12  initiates a telephone call to a selected telephone number by signaling the telephony/voice board  14  to take the telephone dialer  10  off hook. The program in the personal computer  12  then accesses the database for the selected telephone number to be called and provides a sequence of digits to the telephony/voice board  14  corresponding to the telephone number. Upon receiving a dial tone from the public switched telephone network (PSTN), the telephony/voice board  14  converts each digit received from the personal computer  12  to a DTMF tone and transmits a sequence of the DTMF tones to the PSTN  20 . The telephony/voice board  14  then waits for an off hook signal to be received from the called telephone  30  (step  104 ). If a system information tone signal (SIT) or a busy signal is received before an off hook signal is received from the called telephone  30 , or the off hook signal is not received within a predetermined time, such as for an unanswered call, the personal computer  12  resets the telephony/voice board  14 . The personal computer  12  then signals the telephony/voice board  14  to take the telephone dialer  10  off hook and to initiate the dialing sequence for a new telephone number (step  102 ). If on the other hand, the off hook signal is received 104 within the predetermined time, the telephony/voice board  14  is enabled to detect a zapping device  40 . In the preferred embodiment, the telephony/voice board  14  detects a zapping device  40  by detecting a first tone of a tone sequence having predetermined features (step  106 ). Preferably the first tone is the first tone of an SIT signal and more preferably, the first tone is the first tone of an operator intercept signal (OI). If the first tone is not detected, the telephone dialer  10  assumes that a zapping device  40  is not on the line. The telephony/voice board  14  of the telephone dialer  10  then determines if the telephone call is being answered by a modem or a facsimile, a person or an answering machine (step  110 ). 
     If the telephony/voice board  14  determines that the telephone call was answered by a person, the telephony/voice board  14  signals the personal computer  12 , which then retrieves from the computer memory a recorded message corresponding to the called telephone number. The personal computer  12 , upon retrieving the recorded message, transmits the message to the telephony/voice board  14  which then transmits the message through the PSTN  20  to the customer premises  30  (step  112 ). Upon completing the transmission, the personal computer  12  then commands the telephony/voice board  14  to terminate the call and, if there are additional calls to be made, initiates the dialing sequence for a new telephone number (step  102 ). 
     If the telephony/voice board  14  determines that the telephone call was answered by an answer machine, the telephony/voice board  14  signals the personal computer  12  which then commands the telephony/voice board  14  to detect the ending tone of the answer machine (step  114 ). When the telephony/voice board  14  detects the ending tone, the telephony/voice board  14  signals the personal computer  12  which then retrieves from the computer memory a recorded message corresponding to the called telephone number. The personal computer  12 , upon retrieving the recorded message, transmits the message to the telephony/voice board  14  which then transmits the message through the PSTN  20  to the customer premises  30  (step  112 ). Upon completing the transmission, the personal computer  12  then commands the telephony/voice board  14  to terminate the call and, if there are additional calls to be made, initiates the dialing sequence for a new telephone number (step  102 ). 
     If the telephony/voice board  14  determines that the telephone call was answered by a facsimile machine or a modem, the telephony/voice board  14  signals the personal computer  12  which then commands the telephony/voice board  14  to detect the connection sequence of the facsimile machine or the modem (step  116 ). When the telephony/voice board  14  detects completion of the connection sequence, the telephony/voice board  14  signals the personal computer  12 , which then retrieves from the computer memory a facsimile message or a data message corresponding to the called telephone number. The personal computer  12 , upon retrieving the message stored in the computer memory, transmits the message to the telephony/voice board  14  which then transmits the message through the PSTN  20  to the customer premises  30  (step  112 ). Upon completing the transmission, the personal computer  12  then commands the telephony/voice board  14  to terminate the call and, if there are additional calls to be made, initiates the dialing sequence for a new telephone number (step  102 ). 
     If on the other hand, the telephony/voice board  14  detects the first tone, the telephony/voice board  14  is enabled to detect a second tone. If a second tone having predetermined characteristics is detected (step  108 ), the telephone call is terminated and a new call to a new telephone number is initiated, as described above. Preferably, the second tone is the third tone of an OI sequence. If the second tone is not detected at step  108 , the telephone dialer  10  determines that the first tone was generated by a zapping device  40 . The telephony/voice board  14  of the telephone dialer  10  then determines if the telephone call is being answered by a modem or a facsimile, a person or an answering machine (step  110 ) and transmits the message to the customer premises as described above. 
     It should be understood that the invention is not limited to detecting the specific tone sequences and frequencies of system information tones as generally practiced in the United States. The invention is equally applicable to telephone systems which use tone sequences for indicating network conditions having different timing and frequencies than the aforementioned system information tones. 
     Visual Basic Source Code for detection of the phone zapper is:
         Private Sub Voice 1_ToneDetected(ByVal ToneNumber As Integer)   Select Case ToneNumber
           Case 1 ‘Tone 1 is defined to detect a TeleZapper
               DetectedTeleZapper=True   
               Case 2 ‘Tone 2 is defined to detect an OI
               DetectedTeleZapper=False   DetectedOI=True   
               
               

     End Select 
     End Sub 
     As would be appreciated by persons of ordinary skill in the art, other programming languages could be used for programming the telephone dialer  10 . 
     The present invention provides an improved telephone dialer whereby the presence of a zapping device on a customers telephone line will not prevent important messages to be delivered to the customer&#39;s premise. 
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.