Abstract:
Method and apparatus for providing and using a telephone calling card are described. In one example, a planar body includes a memory system, a dual-tone multi-frequency (DTMF) generator, and a speaker. The memory system is configured to store identification data for allowing a user to place a telephone call. The DTMF generator is coupled to the memory system and is configured to generate password-protected DTMF tones to convey the identification data. The speaker is coupled to the DTMF generator and is configured to emit the DTMF tones. The DTMF tones may be played into a telephone for making a call using the telephone calling card apparatus. Since the identification data (e.g., account number and/or personal identification number) is played into the telephone and password-protected, rather than being manually entered by the user, the identification data is less susceptible to unauthorized disclosure and thus less susceptible to fraudulent use.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority to U.S. provisional application Ser. No. 60/817,409, filed Jun. 30, 2006, which is incorporated by reference herein in its entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the invention  
         [0003]     The present invention relates generally to telephone systems and, more particularly, to a method and apparatus for providing and using a telephone calling card.  
         [0004]     2. Description of the Related Art  
         [0005]     The use of telephone calling cards is well known. For example, a customer may receive a telephone card that authorizes telephone call charges to be charged to the customer&#39;s account. Typically, the user has to dial a number associated with the calling card processing service and is prompted to dial-in an account number and a personal identification number (PIN) for authentication and authorization purposes. Once the authorization and authentication step is complete, the caller is prompted to dial the called party&#39;s telephone number and charges for the call are charged to the customer&#39;s account. These types of calling card are susceptible to fraud if the account number and the PIN are disclosed to unauthorized users. One well known fraud technique is to monitor a person making a call using a calling card. By monitoring and recording the numbers being dialed into the phone, a person can determine the numbers which need to be dialed to gain access to the account and thus can make unauthorized telephone calls using the account.  
         [0006]     One technique for combating this type of fraud requires the use of a specialized phone having a magnetic card reader. The account and PIN information is embedded in a magnetic strip on the calling card. When a card holder wants to use the calling card, the card is inserted into the magnetic card reader and the account and PIN information can be read. This method of automatically reading the account and PIN information obviates the necessity of the user having to dial this information using the key pad. Therefore, the account and PIN information is not inadvertently disclosed to a third person monitoring the use of the phone by a user. A major disadvantage to this technique, however, is that this calling card can only be used with phones having the capability to read the magnetic strip.  
         [0007]     Accordingly, there exists a need in the art for a method and apparatus for providing and using a telephone calling card that prevents fraud and does not require specialized telephone equipment to use.  
       SUMMARY OF THE INVENTION  
       [0008]     An aspect of the invention relates to a telephone calling card apparatus. A planar body includes a memory system, a dual-tone multi-frequency (DTMF) generator, and a speaker. The memory system is configured to store identification data for allowing a user to place a telephone call. The DTMF generator is coupled to the memory system and is configured to generate DTMF tones to convey the identification data. The speaker is coupled to the DTMF generator and is configured to emit the DTMF tones. The DTMF tones may be played into a telephone for making a call using the telephone calling card apparatus. Since the identification data (e.g., account number and/or personal identification number) is played into the telephone, rather than being manually entered by the user, the identification data is less susceptible to unauthorized disclosure and thus less susceptible to fraudulent use.  
         [0009]     Another aspect of the invention relates to processing a telephone call. Dual-tone multi-frequency (DTMF) tones generated by a DTMF generator on a calling card are received from a first endpoint. The DTMF tones convey identification data associated with a user. The identification data is validated. A telephone number for a call is obtained from the user. The call is routed from the first endpoint to a second endpoint associated with the telephone number. In some embodiments, the first and second endpoints are coupled to the public switched telephone network (PSTN). The call is routed over a packet network. In this manner, a call between non-subscribers to voice-over-internet-protocol (VoIP) technology may be handled using VoIP technology. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.  
         [0011]      FIG. 1  is a block diagram depicting an exemplary embodiment of a communication system in accordance with one or more aspects of the invention;  
         [0012]      FIG. 2  is a flow diagram depicting an exemplary embodiment of a method of processing a telephone call in accordance with one or more aspects of the invention;  
         [0013]      FIG. 3  is a block diagram depicting an exemplary embodiment of the secure calling card in accordance with one or more aspects of the invention;  
         [0014]      FIG. 4  is a block diagram depicting another exemplary embodiment of a communication system in accordance with one or more aspects of the invention; and  
         [0015]      FIG. 5  is a flow diagram depicting another exemplary embodiment of a method of processing a telephone call in accordance with one or more aspects of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0016]      FIG. 1  is a block diagram depicting an exemplary embodiment of a communication system  100  in accordance with one or more aspects of the invention. The communication system  100  includes a first endpoint  102 , one or more communication networks  104 , a call processor  106 , and a second endpoint  107 . The communication networks  104  may include various types of circuit-switched and/or packet networks, which may comprise the public switched telephone network (PSTN), voice-over-internet-protocol (VoIP) networks, the Internet, and the like. A more detailed example of the communication networks  104  is described below with respect to  FIG. 4 . The endpoints  102  and  107  may include various types of devices capable of making and receiving telephone calls over the communication networks  104 , including time division multiplexed (TDM) phone (i.e., a conventional telephone), an internet protocol (IP) phone, a computer, or the like. Among other well known components, the endpoints  102  and  107  include a microphone  108  for capturing sound and a speaker  110  for emitting sound.  
         [0017]     The call processor  106  includes various devices and systems for implementing a call processing center. The call processor  106  is configured to perform one or more functions, including the processing of telephone calls made using telephone calling cards. The call processor  106  may be coupled to a database  112  that maintains data associated with calling card accounts. Such data may include account identifiers and/or personal identification number (PINs) associated with telephone calling cards. The telephone calling cards handled by the call processor  106  may be conventional calling cards, where users use the cards to make telephone calls that are then billed to the corresponding accounts. Other exemplary telephone calling cards include “pre-paid” calling cards. A pre-paid calling card is associated with an account that is pre-loaded with a block of minutes to be used. A customer purchases the pre-paid calling card for a particular fee. In essence, a user purchases a block of minutes to be used to make telephone calls. As the users make telephone calls, the balance is debited from the associated pre-paid calling cards for the amount of time spent for each call. Some pre-paid calling cards are disposed of when the balance in the account is depleted. Other pre-paid calling cards may be “re-charged” by purchasing additional minutes.  
         [0018]     In some embodiments, a call is made from the first endpoint  102  to the second endpoint  107  using a secure telephone calling card (“secure calling card  114 ”). The secure calling card  114  obviates the need for a user  116  to dial or otherwise enter identification data, such as an account number and/or PIN number. Rather, the secure calling card  114  is configured to generate and play a sequence of dual-tone multi-frequency (DTMF) tones upon command of the user  116 . The DTMF tones convey identification data to making telephone calls, such as an account number and/or PIN number. The user  116  positions the secure calling card  114  such that the DTMF tones are captured by the microphone  108  of the first endpoint  102 . In this manner, the secure calling card  114  substantially reduces the risk that the identification data (e.g., account number and/or PIN) are illicitly obtained by third parties as the user  116  uses the card. Exemplary embodiments of the secure calling card  114  are described below.  
         [0019]      FIG. 2  is a flow diagram depicting an exemplary embodiment of a method  200  of processing a telephone call in accordance with one or more aspects of the invention. The method  200  may be understood with reference to the communication system  100  of  FIG. 1 . The method  200  begins at step  202 , where the user  116  activates the secure calling card  114  to generate DTMF tones such that the DTMF tones are captured by the microphone  108  of the first endpoint  102 . In some embodiments, the DTMF tones convey a telephone number of the call processor  106  (e.g., a toll-free telephone number associated with a brand of calling cards). In other embodiments, the user  116  first dials the telephone number of the call processor  106  before playing the DTMF tones into the first endpoint  102 . In any case, the DTMF tones also convey identification data that allows the user  116  to make a telephone call using the secure calling card  114 , such as an account number, a PIN, or both.  
         [0020]     At step  204 , the call processor  106  receives and processes the DTMF tones to validate the identification data. At step  206 , a determination is made whether the identification data is valid. For example, a determination is made whether an account number is valid and exists, whether a PIN number associated with the account is valid, whether the account can be used to make a call (e.g., whether there are minutes pre-paid for on the account), or the like. If the identification data is valid, the method  200  proceeds to step  208 . Otherwise, the method  200  proceeds to step  207 , where the use of the secure calling card  114  by the user  116  is rejected.  
         [0021]     At step  208 , the call processor  106  prompts the user  116  to enter a telephone number, for example, the telephone number of the second endpoint  107 . At step  210 , the call processor  106  receives a telephone number from the user  116  (e.g., the user enters the telephone number using the first endpoint  102  in response to the prompt). At step  212 , the call processor  106  routes a call from the first endpoint  102  to the second endpoint  107 . For example, the call processor  106  causes the second endpoint  107  to indicate an incoming call. If the incoming call is answered at the second endpoint  107 , the call processor  106  facilitates a connection between the first endpoint  102  and the second endpoint  107  through the communication networks  104 .  
         [0022]      FIG. 3  is a block diagram depicting an exemplary embodiment of the secure calling card  114  in accordance with one or more aspects of the invention. The secure calling card  114  includes a generally planar body  302 . The body  302  may be fashioned from plastic, metal, or like-type materials, or a combination of such materials. The body  302  includes a speaker  304 , a DTMF tone generator  306 , switch circuitry  308 , and a memory system  310 . The memory system  310  is configured to store identification data that allows a user to make telephone calls. As described above, the identification data may include an account number, a PIN, or both. The identification data may further include a telephone number of a call processing center. In some embodiments, the memory system  310  comprises a non-volatile memory system, such as a programmable read-only memory (PROM), an erasable PROM (EPROM), an electronically erasable PROM (EEPROM), FLASH memory, or the like. In some embodiments, the memory system  310  may include a removable component, such as a removable FLASH memory card.  
         [0023]     The memory system  310  is accessible by the DTMF tone generator  306 . The DTMF tone generator  306  is configured to read the identification data from the memory system  310  and generate DTMF tones to convey the identification data. The DTMF tone generator  306  drives the speaker  304  to emit the generated DTMF tones. The speaker  304  allows the DTMF tones to be played into a microphone of an endpoint device. The DTMF tone generator  306  is controllable via the switch circuitry  308 . The switch circuitry  308  may include a button or like type activation device on the body  302  of the secure calling card  114 . When the switch circuitry  308  is activated by a user, the DTMF tone generator  306  is commanded to generate the DTMF tones in accordance with the identification data stored in the memory system  310 .  
         [0024]     In an alternate embodiment of the invention, the secure calling card  114  further includes a password generator  316  (OTP generator). The password generator  316  is connected to the DTMF tone generator  306  in any manner necessary and known to those skilled in the art to achieve the desired affect as described below. In one embodiment, the password generator  316  is connected between the switch circuitry  308  and the DTMF tone generator  306  so as to generate a one-time password each time the switch circuitry  308  is activated by a user. The one-time password is, for example, an irreversible transformation value that is representative of DTMF tones when activated via the switch circuitry  308 . Alternately, the password generator  316  can be connected between the switch circuitry  308  and the memory system  310  so that the one-time password is temporarily stored in memory system  310  for instant playback or confirmation with for example, the call processor  106  or similar communication system component. With this feature, the identification data stored in the memory system  310  is encoded differently at each instance of switch circuitry  308  being activated. This further ensures security of the identification data and reduces the likelihood of fraud. In order to “understand” that the one-time password and corresponding tones are identifying a proper user of the system, the call processor  106  or other similar communication system component operates in accordance with a security protocol or process that employs the irreversible transformation. In one embodiment of the invention, the one-time password is HMAC-based One Time Password (HOTP) as seen and described in IETF RFC 4226 herein incorporated in its entirety by reference. Other protocols are possible as known to those skilled in the art including but not limited to S/Key as described in IETF RFC 1760. Note that in the embodiment depicted in  FIG. 3 , the password generator  316  is represented as a hardware module interconnected to other modules of the secure calling card  114 . Alternately, the password generator  316  is represented as a software module containing the necessary code or computer-language instructions to execute the security protocol necessary to provide the one-time password. For example, the password generator  316  may be part of the memory system  310  that is accessed by the DTMF tone generator  306  when the secure calling card  114  is activated.  
         [0025]     In some embodiments, the body  302  further includes a communication interface (I/F)  312 . The communication interface  312  is coupled to the memory system  310 . The communication interface  312  may be used to store identification data to the memory system  310 , or update identification data stored in the memory system  310 . The communication interface  312  may comprise any type of communication circuitry known in the art, including any wired interface (e.g., universal serial bus (USB)), wireless interface, or the like.  
         [0026]     The secure calling card  114  may be associated with a traditional account or a pre-paid account. The memory system  310  may be updated with new identification data over time. For example, in case of a pre-paid card, the memory system  310  may be updated in response to purchase of another block of minutes (e.g., the account number and/or PIN may change for the newly purchased minutes). The memory system  310  may be updated using the communication interface  312 . For example, the communication interface  312  may be coupled to a computer  350  coupled to a network  352 , such as the Internet. In this manner, new or updated identification data may be downloaded from the network  352  through the computer  350  to the secure calling card  114  for storage in the memory system  310 . If the memory system  310  includes a removable component, such as a removable FLASH memory chip, the identification data may be updated by inserting a new removable component into the memory system  310 . Alternatively, the removable component may be removed, updated, and re-inserted into the memory system  310 . Those skilled in the art will appreciate that there are a myriad of possible mechanisms for updating the identification data in the memory system  310 .  
         [0027]     For purposes of clarity by example, the speaker  304 , the DTMF tone generator  306 , the switch circuitry  308 , the memory system  310 , and the communication interface  312  are shown as separate functional elements. Those skilled in the art will appreciate that one or more of such components may be combined and implemented as a single device, such as an integrated circuit (IC). In any case, the electrical components on the secure calling card  114  are coupled to a power source  314  in the body  302 . The power source  314  may comprise any type of power source known in the art, including a battery, solar power cells, or the like.  
         [0028]      FIG. 4  is a block diagram depicting another exemplary embodiment of a communication system  400  in accordance with one or more aspects of the invention. The communication system  400  shows a more detailed embodiment of the communication system  100  of  FIG. 1 . The communication system  400  includes a circuit-switched network  402 , one or more packet networks  404 , and a circuit-switched network  406 . The circuit-switched networks  402  and  406  may be part of the same network, generally referred to as the Public Switched Telephone Network (PSTN). As is well known in the art, the PSTN comprises a collection of local exchange carriers (LECs) and inter-exchange carriers (IXC). The packet networks  404  may comprise various interconnected internet protocol (IP) networks operated by various entities. At least a portion of the packet networks  404  may be generally referred to as the Internet.  
         [0029]     In the present example, a first telephone  408  is coupled to the circuit-switched network  402 , and a second telephone  410  is coupled to the circuit-switched network  406 . The telephones  408  and  410  comprise traditional telephones coupled to the PSTN and may be referred to as PSTN telephones. The packet networks  404  are also used to carry telephone calls, such service generally referred to as voice-over-internet-protocol (VoIP). For example, VoIP technology allows users to place telephone calls through the Internet, rather than using the PSTN. In the present example, a third telephone  412  is coupled to a terminal adapter (TA)  414 , which is in turn coupled to the packet networks  404 . One of the functions of the TA  414  is to convert the voice signals to digital data packets for transmission over the packet networks  404 . Some phones have built-in terminal adapters and are typically referred to as IP phones.  
         [0030]     Also in the present example, a personal computer (PC)  416  is coupled to a router  419 , which is in turn coupled to the packet networks  404 . As a PC typically includes a microphone and speaker, the PC  416  can also be used as a telephone (e.g., using a “softphone” application) thereby operating similarly to the third telephone  412  and TA  414 . The PC  416  performs the function of the TA to covert voice signals to digital data packets for transmission over the packet networks  404 . Although telephones and PCs are shown by example, those skilled in the art will appreciate that other types of devices may be used to implement VoIP telephones, such as notebook computers, personal digital assistants (PDAs), and the like.  
         [0031]     In some cases, a user of a PSTN telephone will call a user of a VoIP telephone, such as a call between the first telephone  408  and the third telephone  412  (PSTN-to-VoIP call flow). In such cases, a user of the first telephone  408  dials the phone number assigned to user of the third telephone  412 . The circuit-switched network  402  recognizes the telephone number as a number associated with a VoIP service provider and transmits the call to an inbound point of presence (POP) or regional data center (RDC) (“inbound POP/RDC  418 ”). The inbound POP/RDC  418  provides an interface between the circuit-switched network  402  and the packet networks  404 . The inbound POP/RDC  418  provides the call to a call processing center  420  of the VoIP service provider via the packet networks  404 . The call processing center  420  obtains the IP address of the TA  414  associated with the telephone. The call processing center  420  then signals the TA  414  of the incoming call. The signaling between the inbound POP/RDC  418  and the call processing center  420 , and between the call processing center  420  and the TA  414 , may be performed using various signaling protocols, such as the Session Initiation Protocol (SIP) as identified in the Internet Engineering Task Force (IETF) RFC 3261 (herein incorporated by reference) or the like. If the call is answered at the third telephone  412 , a voice stream is established between the TA  414  and the inbound POP/RDC  418  over the packet networks  404 , such as a real-time transport protocol (RTP) stream or the like. The inbound POP/RDC  418  converts the voice stream for transmission over the circuit-switched network  402  to the first telephone  408 . At the end of the call, the inbound POP/RDC  418  and the TA  414  signal the call processing center  420  that the call has ended. As a result, the call processing center  420  can determine the appropriate billing information. The above-described call flow is merely exemplary and various details related thereto have been omitted for clarity.  
         [0032]     In other cases, a user of a VoIP telephone will call a user of a PSTN telephone, such as a call between the third telephone  412  and the second telephone  410  (VoIP-to-PSTN call flow). In such cases, a user of the third telephone  412  dials the phone number assigned to the user of the second telephone  410 . The call processing center  420  recognizes the telephone number as being a standard PSTN telephone number and provides the call to an outbound POP or RDC (“outbound POP/RDC  422 ”) via the packet networks  404 . The outbound POP/RDC  422  provides an interface between the packet networks  404  and the circuit-switched network  406 . The outbound POP/RDC  422  coverts the IP data to time division multiplexed (TDM) format, which is handed off to the circuit-switched network  406 . The circuit-switched network  406  then signals the second telephone  410  of the incoming call in a conventional manner. The signaling between the outbound POP/RDC  422  and the call processing center  420 , and between the call processing center  420  and the TA  414 , may be performed using various signaling protocols, such as SIP or the like. If the call is answered at the second telephone  410 , a voice stream is established between the TA  414  and the outbound POP/RDC  422  over the packet networks  404 , such as an RTP stream or the like. At the end of the call, the outbound POP/RDC  422  and the TA  414  signal the call processing center  420  that the call has ended. As a result, the call processing center  420  can determine the appropriate billing information. The above-described call flow is merely exemplary and various details related thereto have been omitted for clarity.  
         [0033]     In the above-described call flows, one of the users has subscribed to VoIP technology (e.g., the user of the third telephone  412 ). Users who have not subscribed to VoIP technology have not previously been given the option of using VoIP technology for calls placed to other non-subscribing users. For example, a call between the telephone  402  and the second telephone  410  is typically facilitated using only the PSTN (circuit switched networks  404  and  406 ). In some embodiments of the invention, users of PSTN telephones can selectively use VoIP technology, even when the users are non-subscribers to VoIP technology and are calling other non-subscribers of VoIP technology (e.g., a call between PSTN phones). This may be done using the secure calling card  114 .  
         [0034]      FIG. 5  is a flow diagram depicting an exemplary embodiment of a method  500  of processing a telephone call in accordance with one or more aspects of the invention. The method  500  may be understood with reference to the communication system  400  of  FIG. 4 . In particular, a user of a PSTN telephone (e.g., the telephone  402 ) obtains the secure calling card  114  provided by a VoIP service provider. Assume the VoIP service provider that provides the secure calling card  114  also operates the inbound and outbound POP/RDCs  418  and  422 , as well as the call processing center  420 . The call processing center  420  is coupled to the PSTN (e.g., the circuit-switched network  404  and/or the circuit switched network  406 ). Thus, in some embodiments, the call processing center  420  provides a similar function as the POP/RDC, i.e., interfacing between the packet networks  404  and the PSTN.  
         [0035]     The method  500  begins at step  502 , where the user activates the secure calling card  114  to generate DTMF tones such that the DTMF tones are captured by a PSTN telephone (e.g., the telephone  402 ). In some embodiments, the DTMF tones convey a telephone number of the call processing center  420  (e.g., a toll-free telephone number associated with a brand of calling cards). In other embodiments, the user first dials the telephone number of the call processing center  420  before playing the DTMF tones into the telephone  402 . In any case, the DTMF tones also convey identification data that allows the user to make a telephone call using the secure calling card  114 , such as an account number, a PIN, or both. In one embodiment, the DTMF tones are repeated at every instance of secure calling card  114  activation. Alternately, the DTMF tones are randomly generated at every instance of secure calling card  114  activation for further fraud prevention.  
         [0036]     At step  504 , the call processing center  420  receives and processes the DTMF tones to validate the identification data. At step  506 , a determination is made whether the identification data is valid. For example, a determination is made whether an account number is valid and exists, whether a PIN number associated with the account is valid, whether the account can be used to make a call (e.g., whether there are minutes pre-paid for on the account), or the like. If the identification data is valid, the method  500  proceeds to step  508 . Otherwise, the method  500  proceeds to step  507 , where the use of the secure calling card  114  by the user is rejected.  
         [0037]     At step  508 , the call processing center  420  prompts the user to enter a telephone number, for example, the telephone number of a PSTN telephone (e.g., the second telephone  410 ). At step  510 , the call processing center  420  receives a telephone number from the user (e.g., the user enters the telephone number using the telephone  402  in response to the prompt). At step  512 , the call processing center  420  routes a call from the telephone  402  to the called telephone using the packet networks  404 . The call processing center  420  receives and packetizes the voice signals from the telephone  402  for transmission over the packet networks  404 . If the called telephone is a VoIP telephone (e.g., the third telephone  412 ), the call processing center  420  routes the call to the TA  414  through the packet networks  404 , as described above in the PSTN-to-VoIP call flow. If the called telephone is a PSTN telephone (e.g., the second telephone  410 ), the call processing center  420  routes the call to a POP/RDC (e.g., the outbound POP/RDC  422 ) through the packet networks  404 , as described above in the VoIP-to-PSTN call flow. In this manner, a call between two PSTN telephones may be facilitated using VoIP technology.  
         [0038]     While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.