This invention generally relates to telephone systems. In particular, the invention relates to telephone systems for making prepaid or post-paid long-distance and international telephone calls.
Private telephones located at residences or businesses typically are billed on a monthly basis by the local and long-distance carriers. Wireless telephones are also available on the same basis, provided that the customer is able to meet various standards of credit-worthiness. People can also use public telephones by depositing coins, charging the call to a credit card, or charging the call to a different telephone number using telephone debit cards.
An alternative method of paying for phone calls, which is becoming increasingly prevalent, is to provide prepaying customers with a special code or PIN number which can be used (provided that the prepayment has not been exhausted) at any time to make a phone call. The telephone service is provided by the telephone carrier to whom the prepayment was made. As used herein, the term xe2x80x9cprepaid telephone systemxe2x80x9d means a system in which each prepaying customer is given a unique special code for use in making telephone calls until the prepayment has been exhausted.
A prepaid telephone system and a method for making prepaid telephone calls are disclosed in U.S. Pat. No. 4,706,275 issued to Zvi Kamil. The method comprises the steps of: obtaining a special code by making a prepayment; storing the special code and associated prepayment amount in a memory in a special exchange; connecting to the special exchange when a telephone call connection is desired; transmitting the special code and the number of the called party to the special exchange; verifying that the special code is valid and that the available credit is sufficient to cover the initial cost of the call; connecting the calling party station to the called party station in response to verification; and disconnecting the call when the available credit has been spent. The xe2x80x9cspecial exchangexe2x80x9d referred to in U.S. Pat. No. 4,706,275 is a telephone switching matrix having an associated computer and memory for performing the special functions of verifying and monitoring prepaid telephone calls. The prepaid customers can connect to the special exchange via either a wire (land) line or a wireless connection. The term xe2x80x9cspecial exchangexe2x80x9d will be used in the same sense herein.
The method disclosed in U.S. Pat. No. 4,706,275 has been widely adopted in the telephone industry. Generally, each prepaid carrier has its own special exchange to which its prepaid customers are able to connect. Initially, the prevailing application of the teaching of U.S. Pat. No. 4,706,275 was in the context of public telephone connected to a special exchange via a land line. In recent years the teaching of U.S. Pat. No. 4,706,275 has been widely adopted by wireless carriers.
In the typical land-line prepaid telephone system, the customer purchases a prepaid telephone card which has a special code, also known as a PIN number, printed on the back of the card. Typically the PIN number is obscured by a layer of opaque material which is removed after purchase to reveal the secret PIN number to the cardholder. The prepaid telephone card also have one or more access phone numbers printed thereon. At the time of card purchase, the PIN number and prepayment amount (i.e., value of the card purchased) are recorded by the card issuer and then forwarded to the service provider for storage in computer memory at a special exchange operated by the prepaid telephone service provider. When the customer wishes to make a prepaid telephone call, he/she first dials the access phone number to connect to the special exchange. When the connection is made, the customer is prompted by a computer to enter the PIN number and the destination phone number. The special exchange then determines whether the call should be connected by verifying that the PIN number is valid and that sufficient prepaid balance is available to cover the cost of the call to the destination phone number. If the PIN number is valid and the available balance is sufficient, the call is connected. The running cost of the call is monitored, either by computing the running cost or by calculating the airtime available (based on the charge per minute and the available balance) and then subtracting the call duration from the available airtime. When the available balance/available airtime has been exhausted, the telephone call is disconnected.
The technique for making a prepaid wireless telephone call differs somewhat from the land-line technique. In one type of prepaid cellular (wireless) telephone system, a predetermined amount of airtime may be purchased at the time when the handset is purchased. At the time of the transaction, the purchaser is given a multi-digit Electronic Serial Number (ESN) and a multi-digit purchase identification number (PIN). The ESN, which is imprinted on a plate affixed to the inside of the handset, uniquely identifies that handset. The PIN number merely identifies the particular transaction by which airtime was purchased. After leaving the store with the handset and PIN number, the purchaser may call the central office of the wireless carrier to activate the cellular telephone. At that time, the handset purchased by the pre-paid customer is assigned a 10-digit telephone number, also known as the Mobile Identification Number (MIN), which uniquely identifies that handset. The activated handset will respond to that MIN and will also transmit that MIN along with the ESN when a call is being made from that handset.
The fundamental difference between prepaid and non-prepaid cellular telephone systems is the requirement that the prepaid system only connect the desired call if a certain minimum prepaid credit amount (associated with the particular handset being used) is available. One type of prepaid cellular telephone system employs a prepaid platform comprising a switching matrix, memory for storing MINs and prepaid credit amounts, and a computer (e.g., a central processing unit) for controlling the switches of the switching matrix in dependence on whether a particular MIN of a calling party is valid and whether the required prepaid amount of credit is available, both of which pieces of information are stored in memory and retrieved by the computer of the prepaid platform.
The prepaid platform for performing the verification and monitoring functions may be situated on the same premises as the wireless carrier""s central switching system, hereinafter xe2x80x9cmobile telephone switching officexe2x80x9d (MTSO), or may be situated away from the MTSO. In either case, the MTSO computer is connected to the prepaid platform computer via a communications link. For example, the prepaid platform may interface with the MTSO via a T1 communications link. Alternatively, the same computer may perform the functions of both the MTSO and the prepaid platform. In the subsequent description of the functionality of an exemplary cellular telephone exchange comprising an MTSO and a prepaid platform, it should be understood that the respective functions being described can be performed by a single processor having sufficient computing power, rather than by two processors connected by a communications link.
In one example of a prepaid cellular telephone system, the ESN and MIN are stored in the MTSO""s computer memory at the time of handset activation. Also, the MIN and the prepaid amount of airtime/credit are stored in the computer memory of the prepaid platform. When the handset user wishes to make a phone call, the user enters the destination phone number (including the area code if necessary) he wishes to call and then presses the TALK button. When the TALK button is depressed, the ESN, the MIN and the destination phone number are transmitted by the handset in the form of radiofrequency signals. These radio signals are received by the nearest cellular telephone tower, which relays the ESN, MIN and destination phone number to the MTSO, also by transmitting radiofrequency signals. The receiver at the MTSO receives the transmitted signals from the cell tower, which signals carry the ESN, MIN and destination phone number. The computer at the MTSO first matches the ESN to the MIN to ensure against fraud. This is done by comparing the incoming ESN and MIN with the corresponding pair stored in computer memory at the MTSO. If the ESN matches the MIN, the MTSO then determines whether the MIN identifies a prepaid customer. If the determination is affirmative, the MTSO computer hands the call of f to the prepaid platform via the communications link.
In response to receipt of the MIN and the destination phone number, the computer at the prepaid platform verifies that the MIN is valid and checks the available prepaid credit balance associated with the transmitted MIN to make sure that sufficient credit is available to cover the initial cost of the requested telephone call. These verifications are carried out by comparing the received numbers with the corresponding numbers stored in the prepaid platform memory. If there is sufficient credit available, the prepaid platform computer hands the call back to the MTSO via the communications link. The MTSO computer then initiates operation of the appropriate switches needed to route the cellular telephone call to the destination phone number. Alternatively, if the prepaid platform has its own telephone switching matrix, the prepaid platform can route the call through its own switches.
Upon establishment of a connection between the handset user and the called party, the prepaid platform monitors the call. If the prepaid credit balance is exhausted before the handset user disconnects the call, the prepaid platform initiates disconnection of the call. Then the prepaid platform computer will decrement the available credit balance by the cost of the completed telephone call.
In another type of prepaid cellular telephone system, a cell phone user can prepay for airtime by purchasing a prepaid telephone card from a prepaid carrier different than the wireless carrier from whom the cell phone user has purchased the handset. That prepaid carrier has a special exchange which the cell phone user can access by dialing a special access code, e.g., *999, on his handset. The wireless carrier then forwards the wireless call to the special exchange of the prepaid carrier. Once the connection is made, the cell phone user must input the PIN number which appears on the prepaid telephone card. If the PIN number is valid and if a sufficient amount of prepaid credit is available on that card, the prepaid carrier will route the cell phone user to the station corresponding to the destination telephone number inputted by the user.
Prepaid cellular telephones are ideally suited for persons having a credit rating which falls short of the standard set by a particular wireless carrier as a precondition for purchase of a non-prepaid cellular telephone. One problem, however, is the high cost to the consumer of wireless telephone services and the great variability in the costs charged by different wireless carriers. The carriers that sell prepaid or postpaid wireless telephone service are the providers of the local, long distance or international service. Once a consumer buys a handset and prepaid or postpaid wireless service from a particular carrier, that carrier is the one that generally provides the network service. To the extent that a consumer believes they are captive to the carrier providing local wireless service, that wireless carrier is able to charge above-market rates for long-distance and international telephone service. Although land-line telephone service is generally cheaper than wireless telephone, land-line telephone service providers also charge at rates which vary widely and which may include hidden charges over and above the simple cost per minute charge.
Today any customer that uses prepaid or postpaid wireless or land-line telephone service can buy prepaid land line usage, a prepaid telephone card, or a prepaid dial tone from any vendor carrier for use with any telephone by dialing a toll-free number or dialing directly to the special exchange of that carrier. In the case of land-line telephones, when the customer is connected to that special exchange, he/she is asked to transmit his/her special code number. In the case of wireless telephones, the wireless telephone transmits its MIN number, which serves the function of a special code or PIN number for verifying an authorized prepaid customer. After the special code and credit available have been verified by the special exchange corresponding, e.g., to the land-line prepaid telephone card being used by the customer, the customer can make long-distance and international telephone calls through that special exchange.
Any person has the freedom to select which carrier to purchase prepaid telephone service from. A person may even purchase multiple prepaid telephone calling cards from multiple prepaid service providers. However, in the latter case, it would be extremely inconvenient and time consuming for each consumer to monitor the telephone rates of different prepaid telephone service providers in order to identify the least-cost provider. This is particularly the case where there is a wide disparity in the methods used to compute telephone charges. Even more daunting is the fact that each international telephone service provider charges different rates for calls to different countries. The charges for placing a call from the United States to a particular country may vary widely from carrier to carrier. This is also true of the telephone rates applicable to post-paid long-distance and international telephone service.
Thus there is a need for a method and a system of automatically routing long-distance and international telephone calls to the least-cost carrier in the situation where a consumer is buying long-distance and/or international telephone service from multiple carriers. This need is especially great in the prepaid wireless telephone market, where the carrier who sells the handset and associated prepaid wireless telephone service to the consumer may charge low rates for local telephone service and high long-distance and/or international rates. Such a prepaid wireless carrier has no incentive to help the consumer to buy long-distance and/or international service from its competitors.
The present invention is a method and an apparatus for enabling a consumer to buy long-distance and/or international telephone service at the least cost from any one of a multiplicity of alternative carriers. The invention has application in both prepaid and post-paid telephone systems. In addition, the consumer may make the call from a wireless handset or from telephony equipment connected to a land line. In accordance with the preferred embodiment of the invention, a consumer wishing to make a long-distance or international call may connect to a universal exchange via a wireless or land-line telephone and then be routed by the universal exchange to the least-cost carrier for that particular call. In the case of wireless telephones, the invention will enable the consumer to buy the wireless handset and associated local wireless prepaid or postpaid telephone service from a wireless carrier, while the consumer will be able to buy non-local telephone service from a least-cost carrier selected from a list of long-distance and/or international carriers with which that particular consumer is doing business. In the case of land-line telephones, the invention will enable the consumer to purchase the associated local land-line prepaid or postpaid telephone service, while the consumer will again be able to buy non-local telephone service from a least-cost carrier selected from a list of long-distance and/or international carriers with which that particular consumer is doing business. The non-local portion of the call can be executed by the long-distance/international carrier through the most competitive means, such as the Internet, telephone line, satellite or microwave communications, optical fibers, television cable, copper wire, etc., or through other wireless carriers.
The invention allows a consumer to avoid excessive telephone charges and obtain the most economic long-distance and/or international telephone service. Heretofore, least-cost routing has been used by carriers to decrease their operating costs, but has not been made available to the consumer, In the case of pre-paid cellular telephone service, the invention allows the consumer to buy a handset from a particular wireless carrier and use the same wireless carrier mainly for local wireless calls, while buying long-distance and international telephone service at the lowest possible price, i.e., by buying service on a prepaid or post-paid basis from multiple carriers that compete with each other for the consumer""s business. These alternative carriers can be selectively used to make long-distance and/or international calls at rates which are cheaper than those being offered by the carrier from which the consumer purchased the handset. Although the consumer during, e.g., a long-distance call will be using two telephone services concurrently, i.e., the local carrier and the long-distance carrier, the difference in price between the long-distance rates charged by the local carrier and those charged by the long-distance carrier can be greater than the cost of the local wireless service during the long-distance call, resulting in an economic saving to the consumer.
In accordance with the preferred embodiment of the invention, if the consumer needs to make a prepaid non-local call, then the consumer will make a phone call to a smart exchange that will be referred to herein as a xe2x80x9cuniversal exchangexe2x80x9d. This universal exchange, which may be owned by an independent carrier, will be connected to many participating carriers that provide prepaid or post-paid telephone service. Each carrier will be identified by the universal exchange with a unique carrier code having, e.g., one to five digits. In accordance with the preferred embodiment of the invention, the universal exchange receives and stores telephone rate information for each participating carrier. In addition, the universal exchange is programmed with a least-cost routing function which uses the stored telephone rate information to calculate the cost of a call for each available carrier and then identify the least-cost carrier for that call. Based on that determination, the universal exchange then routes the call to the exchange of that least-cost carrier.
For each customer of the universal exchange, the pool of available carriers will include those carriers participating with the universal exchange and from which the customer has purchased prepaid long-distance or international telephone service, e.g., prepaid telephone calling cards, and those participating long-distance/international carriers which the customers has accounts with. For each participating carrier, the universal exchange will assign a unique carrier code. The universal exchange will also assign a special identification code to each of its customers. In response to messaged requests from the universal exchange computer during an initialization procedure, the customer will provide the carrier codes for the multiple prepaid telephone calling cards and for the multiple telephone accounts held by that customer. This set of carrier codes received by the universal exchange must be associated with the customer identification code of that customer in the universal exchange memory. In the case of a customer who owns a wireless handset, the customer identification code recognized by the universal exchange can be the MIN for that particular handset. In the case of a customer who intends to make calls to the universal exchange from a residential or business telephone, the customer identification code recognized by the universal exchange can be the number for the telephone line to which that telephone is connected. In both of the foregoing cases, the universal exchange can utilize known xe2x80x9ccaller IDxe2x80x9d technology to recognize the calling telephone number. Alternatively, the customer may select or be assigned a unique customer identification code different than his/her telephone number. In the case where the customer uses prepaid telephone calling cards only, the universal exchange customer may remain anonymous, being identified to the to the universal exchange by nothing more than a code or password.
After initialization, the universal exchange is ready to process any telephone call from the customer. For a particular telephone call, the universal exchange needs to receive only the customer identification code of the customer and the destination phone number. Based on the prestored list of carriers for which that particular customer is holding prepaid calling cards or has accounts and the associated rate schedules and based on the destination of the telephone call, the universal exchange identifies and routes the call to the exchange of the least-cost carrier. That exchange then processes the call. In the case of a pre-paid least-cost carrier, the exchange to which the call is routed will be a special exchange. In the case of a post-paid least-cost carrier, the exchange to which the call is routed will be a regular exchange. In addition to be able to connect to any participating carrier, it must be appreciated that once a customer has a subscription or account with the universal exchange, the customer can access the universal exchange from any telephoning means via any known telecommunications channel, whether it be a land-based telephone line or a wireless communications link.
In accordance with one preferred embodiment, if the least-cost carrier is a prepaid carrier, the special exchange of that least-cost prepaid carrier interacts directly with the customer once the call has been routed by the universal exchange. For example, before the call is routed by the special exchange of the least-cost prepaid carrier, that special exchange will ask the customer to enter his PIN number. Then the special exchange will verify that prepaid credit corresponding to that PIN number is available. If the PIN number is valid and sufficient prepaid credit is available, the special exchange of the least-cost prepaid carrier will route the call to the station identified by the destination telephone number. On the other hand, if the least-cost carrier is a post-paid carrier, then the universal exchange routes the call to the regular exchange of that least-cost post-paid carrier, who will bill the customer""s account accordingly.
In accordance with another preferred embodiment, the PIN numbers corresponding to the carrier codes of prepaid carriers are communicated to the universal exchange by the customer during the initialization procedure. These PIN numbers are stored with the corresponding carrier codes in memory at the universal exchange. Each PIN number identifies a respective prepayment transaction in which the customer has purchased future telephone service to be provided by a respective one of a plurality of prepaid carriers. After the universal exchange performs its least-cost routing routine and if a least-cost prepaid carrier has been identified, the universal exchange routes the call to the special exchange corresponding to the least-cost prepaid carrier, along with the corresponding PIN number. Then the special exchange of the least-cost prepaid carrier verifies the PIN number and associated available prepaid credit, and routes the call to the station identified by the destination telephone number. This embodiment has the advantage that the customer is relieved of the inconvenience of inputting the PIN number for each telephone call, but rather need input the PIN number only once, namely, during the initialization procedure.
A further preferred embodiment comprises a system and a method for routing a prepaid telephone call comprising the steps of: receiving a telephone call from a customer who has purchased prepaid airtime from a plurality of prepaid carriers; determining which prepaid carrier is the least-cost prepaid carrier for that telephone call; routing the telephone call to that least-cost prepaid carrier; receiving a message from the least-cost prepaid carrier indicating that the prepaid airtime purchased from that carrier by that customer is exhausted or nearly exhausted; and re-routing the telephone call to one of the other prepaid carriers, e.g., the second-lowest-cost prepaid carrier, in response to receipt of the message.
In accordance with an alternative preferred embodiment, the verification and monitoring functions performed by special exchanges may be performed by the universal exchange, which acts as a service bureau for the prepaid carriers. In this case, the customer must also input, e.g., via the telephone keypad, the PIN numbers during initialization. In addition, the PIN number and prepayment amount for each calling card must be received from all prepaid carriers served by the universal exchange. That information is stored in memory along with the corresponding carrier codes. If the universal exchange identifies a least-cost carrier from amongst the available prepaid carriers listed in memory for a particular customer, the universal exchange then uses the PIN number for the selected carrier, which PIN number was previously inputted by the customer, and matches that PIN number with a corresponding PIN number in the table of prepayment amounts. The universal exchange then verifies the available prepaid credit amount corresponding to the PIN number of the selected carrier, i.e., the least-cost routing routine excludes as least-cost carrier any carrier for which the available balance is insufficient to cover the initial cost of the telephone call to the station identified by the destination telephone number. If the customer has sufficient available prepaid credit with the selected least-cost carrier, the universal exchange routes the call to that least-cost carrier. Once the customer is connected to the station identified by the destination telephone number, the universal exchange can monitor the ongoing telephone call.
The foregoing method and system will enable the consumer to call any place in the world at the cheapest rate using least-cost routing amongst the different non-local carriers participating with the universal exchange and with which the customer has an account (in the case of post-paid telephone service) or a prepaid balance (in the case of prepaid telephone service).
In accordance with a further alternative preferred embodiment, the universal exchange monitors the quality of the connection made by the least-cost carrier. If the connection is unsatisfactory, e.g., because of diminished signal strength or excessive interference, the universal exchange can automatically re-route the call to the second-lowest-cost carrier.
In addition, the universal exchange enables a consumer to use one telephone line to connect to multiple parties for making a conference call. The universal exchange accomplishes this by routing calls to two or more conference participants via respective exchanges of carriers which the consumer is doing business with (prepaid or post-paid). Optionally, if the consumer has multiple prepaid PIN numbers with one carrier, the universal exchange can connect multiple parties for a conference call via multiple lines to the special exchange of that carrier. This can be accomplished using known conference-call switching technology in the universal exchange.