HK1060951B - Multiple virtual wallets in wireless devices - Google Patents

Description

Multiple virtual wallets in a wireless device

Reference to related application

This application claims priority under 35u.s.c. § 119 from U.S. provisional patent application No. 60/220,241, filed on 21/7/2000, the disclosure of which is incorporated by reference in its entirety for all purposes.

Background

The present application relates generally to systems having an account management protocol for wireless devices, and in particular, to systems having an account management protocol for monitoring and tracking usage and account activity of wireless devices.

More specifically, the account management system is adapted to the mobile phone so that usage and account activity of the mobile phone can be tracked and monitored on an individual basis. Multiple billing systems are described in U.S. patent nos. 5,325,418 ('418 patent), 5,625,669 (' 669 patent), 5,577,100 ('100 patent), and 6198, 915B1 (' 915 patent), which are incorporated herein by reference. The '418 and' 669 patents describe billing systems with application specific features of post-paid mobile phone services such as mobile phone rental services or controlled mobile phone services. In controlled mobile phone service, capturing phone call data and calculating phone charges for each call enables a service provider (or a company in an intra-corporate system) to limit or at least monitor mobile phone usage prior to periodically billing a cycle. For example, if mobile phone usage exceeds a pre-established limit, the mobile phone may be temporarily disabled or limited until a temporary payment or additional credit resources are obtained. In an intra-community system, a warning message may be sent to a community authority that either allows additional use or temporarily disables the mobile phone. In such systems, the telephone call data is stored in the mobile telephone and then sent to the main processor of the billing. The main processor is typically located in a network separate from the mobile telephone.

With the release of the '418 and' 669 patents, the state of the art has evolved to the point where billing applications in mobile phones are able to internally calculate call charges. As described in the ' 100 and ' 915 patents, such systems minimize the amount of communication traffic required between the service provider's main processor and the mobile phone and thus extend the overall service processing capabilities of the mobile phone system. The '100 and' 915 patents describe billing systems having application-specific features for prepaid mobile telephone services.

The proliferation and use of mobile phones is going to continue due to increased ease of use and lower cost. Many companies now offer mobile phones to employees in order to ensure that such employees remain in contact. Since it is very impractical to carry two mobile phones, these employees inevitably tend to use the mobile phones provided by their companies for business and personal calls. Therefore, to deter abuse and/or provide accurate billing, it is desirable to have the ability to monitor the proper use of company-provided mobile phones and account activity.

Moreover, some mobile phones on the market today provide two-wire or multi-wire functionality. With a two-wire telephone, two telephone wires can be dedicated to handling the first type and the second type of calls, respectively. As a result, account activity for different types of calls needs to be monitored separately. It is therefore desirable to provide a mobile telephone system that is capable of handling and monitoring different types of usage and account activity of wireless devices.

Disclosure of Invention

The system of the present invention relates to wireless communication systems having wireless devices, and in particular, wireless telephones that are part of a wireless communication network. In particular, the present invention relates to wireless devices, such as mobile phones, that include an internal account management application for internal management of various accounts. In an example embodiment, the account management application interacts with a billing application for dynamic (on the fly) communication charge calculation. Such a mobile telephone is typically a cellular telephone in a cellular telephone network, a radiotelephone in a personal communications service network or other communications system, wherein the mobile telephone may be moved from one place to another.

The system of the present invention is intended for use with mobile telephones where real-time calculation of call charges is desired to limit or immediately bill for telephone usage where billing by the public switched service provider as well as the participating wireless service providers is not yet available.

The account management system includes an account management application carried within the wireless device that manages a plurality of accounts. The account management application interacts with one or more billing applications such as complex billing algorithms that utilize multiple factor billing protocols to calculate local charges, roaming charges as the wireless device moves from one area to another, long distance charges, international charges including country independent local charges, and surcharges based on per call or rate. Complex billing algorithms may be extended to provide specific fees or special discounts for service providers or called stations or rewards for data transfer calls.

Billing applications related to mobile phone usage include tariff tables. The tariff table in the wireless device may be periodically changed by wireless communication with the service provider's host processor or customer service representative. A billing application associated with a mobile commerce (m-commerce) transaction obtains a quantity to be deducted from a predetermined communication protocol with a transaction device or customer service representative of a provider.

It should be understood that the billing application may reside in the wireless device or on a network accessible to the wireless device. Depending on design specifications or limitations, the functionality of the account management application may be incorporated into the billing application.

It should also be understood that a wireless device with an account management system may be implemented in an existing wireless communication network without substantial modification to the network, and may be implemented in most existing wireless devices with minimal modification, primarily through reprogramming internal to the wireless device. When existing billing applications residing in the network are utilized by the wireless device, the modifications to most existing wireless devices are even smaller.

Wireless devices, such as mobile phones, currently include an internal processor and sufficient internal memory to incorporate the programs and data storage necessary to implement real-time billing. The account management application and the complex algorithms that provide the multi-factor billing function are sufficiently compact so that the storage and processing of call data can be done in real time and with sufficient accuracy to account for multiple charges from multiple service providers, even for roaming phones. Billing and account management applications should utilize encryption systems to allow secure programming and transactions over the air.

The billing and account management system as described herein provides greater flexibility for customers and businesses in managing the costs of mobile phone usage and mobile commerce transactions, particularly when the costs must be divided into different accounts according to multiple criteria such as business versus individual, or according to different profit centers within the same business. The enhanced flexibility also includes different methods for controlling the charges associated with each account, such as prepaid services or postpaid services with usage restrictions. The present invention describes a system in which a single wireless device can be used for controlled service modes for certain purposes, such as business calls, prepaid service modes for other purposes, such as personal calls, and with additional secure electronic accounts for other mobile commerce transactions.

The system of the present invention is suitable for use with analog or digital cellular telephones, personal communication service networks, and radiotelephones in other wireless communication systems. The system is also suitable for other wireless devices, such as personal digital assistants, used for mobile commerce transactions via short-range radio frequency communication protocols or data-bearing communication services, such as short message services.

A system for processing a plurality of accounts according to the present invention comprises: a wireless device having a user interface, a memory, and an account management application within the memory for internally storing and managing a plurality of accounts; wherein the account management application is capable of selectively billing one of a plurality of internally stored accounts while the wireless device is in use.

A wireless device capable of communicating within a network according to another aspect of the invention comprises: a processor, memory, and an account management application resident on the memory of the wireless device for storing and maintaining a plurality of accounts; a billing application to calculate a fee attributable to use of the wireless device; and a user interface for allowing a user to selectably determine which of a plurality of internally stored accounts to bill for while using the wireless device; wherein the account management application and the billing application function in cooperation with each other to maintain and properly bill a plurality of internally stored accounts.

A mobile phone according to still another aspect of the present invention includes: a user interface, a processor, and a memory, wherein both the first line and the second line are configured within the memory to generate or receive a call; and an account management application residing on the memory of the mobile phone and configured to store and manage a plurality of internally stored accounts; wherein a call generated or received over the first line is credited to one of the plurality of accounts and a call generated or received over the second line is credited to another of the plurality of accounts.

A method for tracking account activity related to usage of a wireless device, in accordance with the present invention, comprises: selecting one of a plurality of accounts for use billing of a wireless device, wherein the plurality of accounts are stored and maintained internally in the wireless device; calculating a charge to be charged to the selected account while the wireless device is in use; causing the wireless device to be used; and adjusting the selected account using the calculated cost.

A method of tracking account activity by a mobile phone having a first line and a second line both configured to make or receive calls according to the present invention, comprising: allocating a first account stored internally for a call generated or received through a first line; assigning a second account stored internally for calls made or received over the second line, wherein the first and second accounts are maintained on the mobile phone; generating or receiving a call over the first or second line; calculating a fee to be paid for the call; and adjusting the first account or the second account based on a charge calculated in dependence on which of the first and second lines the call was made or received.

Other features and advantages of the invention will be apparent from a reference to the remaining portions of the specification, including the drawings and claims. Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings, wherein like reference numbers indicate identical or functionally similar elements.

Drawings

Fig. 1 is a simplified schematic diagram illustrating a typical wireless telecommunications scheme;

fig. 2 is a simplified schematic diagram illustrating an exemplary scheme for transmitting a data bearer message, such as a short message service, to a wireless device;

FIG. 3 is a simplified schematic diagram illustrating a typical wireless transaction scenario; and

fig. 4 is a simplified schematic diagram showing an example embodiment of a wireless device according to the present invention.

Detailed Description

Fig. 1 is a simplified schematic diagram illustrating a typical wireless telecommunications scheme. Network 10 communicates with a wireless device 14, such as a mobile telephone, through a transmitting station 12. Transmitter station 12 communicates with wireless device 14 using over-the-air communication. Over-the-air communication protocols that may be used to enable wireless communication between the wireless device 14 and the network 10 include, for example, GSM, CDMA, TDMA, UMTS, and the like. Other ways and methods of implementing over-the-air communications will be known to those of ordinary skill in the art.

Fig. 2 is a simplified schematic diagram illustrating an exemplary scheme for transmitting a data bearer message, such as a short message service, to the wireless device 14. An application 16 residing on host processor 18 communicates with a data carrier message controller 22 in network 10 using a communication link 20, such as a TCP/IP link over the internet, to send a data carrier message, such as a short message service message, through sending station 12 to wireless device 14, such as a mobile telephone.

Fig. 3 is a simplified schematic diagram illustrating a typical wireless transaction scheme. The vending machine 24 having a short-range radio communication transceiver and the wireless device 14, such as a mobile telephone having a short-range radio communication transceiver, communicate using a short-range radio communication link 26. Short-range radio communication links that may be used to enable wireless communication between the wireless device 14 and the vending machine 24 include, for example, a bluetooth wireless communication link. One of ordinary skill in the art will know of other ways and methods of communicating transaction data between two devices. As another example, the vending machine 24 and wireless device 14, each having a suitable transceiver, may communicate transaction data using a data carrier message service, such as a short message service.

Referring to fig. 4, an exemplary embodiment of a wireless device 14 according to the present invention is shown. According to an example embodiment, the wireless device 14 includes an account management application 30 that can track and monitor usage and account activity of the wireless device 14 on an individual basis. The account management application 30 functions as multiple virtual wallets and is capable of maintaining multiple different accounts billable for calls or transactions processed by the wireless device 14. The different accounts include, for example, traditional post-paid accounts, accounts with post-paid monitored or controlled usage, and pre-paid accounts.

The account management application 30 may reside in executable memory within the wireless device 14. Such memory may be one of any type such as ROM, EPROM, or flash memory. The account management application 30 may store dynamic data in RAM and control data using non-volatile memory such as EEPROM or flash memory. Alternatively, the account management application 30 may reside in a smart card, such as a Universal Subscriber Identity Module (USIM) or a Universal Identity Module (UIM) that may be attached to the wireless device 14.

According to an example embodiment, the account management application 30 also interacts with other applications of the billing application 32 as described below in order to properly manage and process different accounts. The billing application 32 can calculate the caller charge in real time or dynamically. An example of an accounting application 32 is the complex billing algorithm described in the' 100 patent. Complex billing algorithms decompose multiple variables of telephone calls from mobile telephones into billing equations that virtually mirror the factors considered by the public switched network provider and the multi-party participating wireless service providers (more than one in a single call). The resulting call cost accurately approaches the sum of the actual costs to be charged by the multiparty participating service provider, thus enabling the caller cost to be immediately calculated and displayed. Complex billing algorithms may be extended to provide specific fees or special discounts for service providers or called stations or rewards for data transfer calls. The billing application 32 may reside in executable memory within the wireless device 14. Such a memory may be one of any type such as ROM, EPROM or flash memory. The accounting application 32 may store dynamic data in RAM and control data using non-volatile memory such as EEPROM or flash memory. Alternatively, the billing application 32 may reside in a smart card, such as a Universal Subscriber Identity Module (USIM) or a Universal Identity Module (UIM) that may be attached to the wireless device 14. In the alternative, it should also be understood that the accounting application 32 resides in the network 10. Other ways and methods of obtaining and retrieving caller charge information from a billing application resident on network 10 will be known to those of ordinary skill in the art.

It should also be understood that the billing application 32 may reside on the wireless device 14 or on the network 10 to which the wireless device 14 has access. Depending on design specifications or limitations, the functionality of the account management application 30 may be incorporated or combined in the billing application 32.

The wireless device 14 may be programmed with a system as described in U.S. patent No. 6,243,574B 1. In addition to installing account management application 30 and billing application 32, the programming includes providing data to the wireless device 14 such as an initial monetary value for a prepaid account or credit limit. Alternatively, the wireless device 14 may be programmed over the air using DTMF signals or data carrier communication services such as short message service initiated from an application 16 residing on the main processor 18 as described in the' 100 patent.

The wireless device 14 is preferably a contemporaneous (consistency) unit having an LCD display screen for displaying numeric or alphanumeric data such as user menus and warning messages; a keyboard for data entry, such as menu selection; and a timer for determining the duration of the call so that the call cost can be calculated. In the alternative, one of ordinary skill in the art will know that timer information may be obtained from the network 10.

In an example embodiment, the account management application 30 calculates the cost of the call or transaction into an account selected by the user. Account selection is accomplished through a user interface. The user interface allows the user to interact with the account management application 30 and select which account is used for each call or transaction. Moreover, the user interface also allows the user to perform certain account management functions. For example, the user may transfer balances between accounts or perform other typical billing functions through a user interface. As another example, a user, through a user interface, may change an account to one for which a particular call is billed. Preferably, the user interface is implemented in the form of a menu of available accounts presented on the LCD screen of the wireless device 14.

In an example mode of operation, usage and account activity of the wireless device 14 is monitored and tracked as follows. In the case of an outgoing call through the wireless device 14, prior to making such a call, the user selects which account to bill for the call using the user interface. Once the account is selected, the user continues with the normal process of making the call. If, for example, a prepaid account is selected, the accounting application 32 calculates the charge to be debited and thus the account management application 30 debits the selected prepaid account.

Similarly, where the wireless device 14 receives incoming calls, the user selects which account to pay for the call using the user interface before such a call is answered. Once the account is selected, the user continues the normal process of receiving the call. If, for example, a postpaid account is selected, the cost of the call is calculated and the account management application 30 updates the postpaid account accordingly.

As described above, the selected account is charged for the call being handled by the wireless device 14. However, it should be understood that the account may also be charged for any transaction processed by the wireless device 14. That is, the account management application 30 is also capable of monitoring and tracking transactions processed by the wireless device 14. For example, referring to FIG. 3, if the wireless device 14 is used to communicate with the vending machine 24 to make a purchase, the appropriate account on the wireless device 14 may similarly pay for the purchase.

Alternatively, the account management application 30 may automatically select an account to charge from a multi-factor algorithm. For example, where the wireless device 14 is a multi-line mobile phone, the account management application 30 detects which line of the multi-line mobile phone is in use and charges the account associated with that line. The call charge applied to the account is determined by the billing application 32. For example, the account management application 30 may select and apply a post-paid account for calls made or received on one line and a pre-paid account for calls made or received on another line.

In another example embodiment, the account management application 30 can utilize the network 10 automatic number identification feature to determine the telephone number of the device originating the call and to meter the charges for the account associated with that telephone number in a table stored in an EEPROM or flash memory in the wireless device 14. In the event that the calling telephone number is not found in the table, then the default account is charged or the user is prompted to select the account to charge for the call. The timing of the prompts varies depending on the design. For example, if the available prepaid funds and/or credit limits for all potential billable accounts are sufficient, the prompting may occur after the call is ended. Alternatively, the timing of the prompting may also occur at a pre-programmed time for an exhaustion warning of available prepaid funds and/or credit limits for an account based on the time of first reaching such warning, among all potential billable accounts. It will be appreciated that the multi-factor algorithm may include one or more of the factors described above, as well as other factors suitable for selecting an account to charge.

In an example embodiment, the account management application 30 maintains each account according to an algorithm programmed by the service provider or authorized community personnel. For example, the application 16 residing on the main processor 18 may provide secure access to authorized community personnel to enable such personnel to enter control data related to each account. The application 16 may initiate transmission of a data bearer message, such as a short message service message, which when received by the wireless device 14, thereby reprogramming the wireless device 14 with such control data. For example, one account may be set up as a traditional post-paid account with usage restrictions and a second account may be set up as a pre-paid account. The common process requires the user to use only the first account for legitimate business calls. User compliance with such procedures may be monitored via call detail records stored on the wireless device 14 and transmitted to the main processor as described in the '418 and' 669 patents.

It will be appreciated that the call detail record may be recorded in RAM or other memory within the wireless device 14, or alternatively, the call detail record may be stored on a smart card, such as a Universal Subscriber Identity Module (USIM), which may be attached to the wireless device 14.

The control data sent to the wireless device 14 may also be used to determine the outcome of the user's arrival at the usage limit. For example, one such result is for the account management application 30 to generate and send an SMS message, or other data carrier message, to the appropriate community authority alerting the user that the usage limit has been exceeded and that review of the call detail record is warranted. Another such result is for the account management application 30 to temporarily restrict operation of the wireless device 14, allowing only emergency calls and calls to customer representatives until the restriction is removed. If the user utilizes a second account, a prepaid account, the common process allows personal calls on the same wireless device 14. Authorized community personnel may receive an acceptable form of payment from the user and, using the application 16, send control data to the wireless device 14, thus adding money to the prepaid account, similar to that described in the' 100 patent.

In another example embodiment, the application 16 on the main processor 18 can provide secure access to authorized personnel of the service provider or company in the intra-corporate system to change the control data for each account. The application 16 may initiate transmission of a data bearer message, such as a short message service message, which when received by the wireless device 14, thereby reprogramming the wireless device 14 with such control data. Examples of such changes include changes in the rate tables utilized by the billing application 32, changes in the credit limits for a controlled postpaid account, and changes in the funds paid for a prepaid account, among others. Alternatively, the user may be provided over-the-air access to the application 16 on the main processor 18 for limited changes, such as adding funds to a prepaid account using a credit card or a prepaid calling card, similar to the description provided in the' 100 patent. Also, when the user requests an increase in the internal telephone account, an updated tariff table may be sent to the wireless device 14.

In an example embodiment, the account management application 30 can generate an audio alert through a speaker of the wireless device 14 and/or an alert message displayed on an LCD screen of the wireless device 14 to inform the user that she/he is about to run out of credit limits or prepay funds. The warning message includes information identifying the available accounts and the amount of funds or credits remaining.

The system of the present invention provides substantial flexibility through the above-described features. For example, the user of the wireless device 14 is given the flexibility to pay differently on a particular basis for each call. The user wishes to separate and pay for calls based on the characteristics of each call. Business and personal calls handled by the same wireless device 14 may be billed from different accounts. The business calls may be paid from one account and the personal calls may be paid from another account. The user also wishes to use different accounts to pay for different calls; one call is paid from a prepaid account and the other call may be billed to a postpaid account.

It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. All publications, patents, and patent applications mentioned herein are hereby incorporated by reference in their entirety for all purposes.

Claims (45)

1. A system for processing a plurality of accounts, comprising:

a wireless device having a user interface, a memory, and an account management application within the memory for internally storing and managing a plurality of accounts;

wherein the account management application is capable of selectively billing one of a plurality of internally stored accounts while the wireless device is in use.

2. The system of claim 1, wherein the user interface allows a user to determine which of the internally stored accounts should be charged by using a keypad.

3. The system of claim 1, wherein the account management application uses an algorithm to automatically select an account of the plurality of accounts to be billed.

4. The system of claim 1, further comprising:

a billing application to calculate an appropriate fee for using the wireless device;

wherein the account management application functions in cooperation with the billing application to manage multiple accounts.

5. The system of claim 1, wherein the wireless device is capable of making or receiving data communications.

6. The system of claim 1, wherein the selection of the account to be billed in the plurality of accounts is dependent on the origin or destination of the communication.

7. The system of claim 1, wherein the wireless device is a mobile phone.

8. The system of claim 1, wherein the account management application resides on a smart card connectable to the wireless device.

9. The system of claim 1, wherein the account management application resides on internal memory in the wireless device.

10. The system of claim 4, wherein the billing application resides on internal memory in the wireless device.

11. The system of claim 4, wherein the billing application resides on a network.

12. The system of claim 1, wherein the account management application is configured to allow the user to transfer balances between a plurality of accounts.

13. The system of claim 1, wherein the plurality of accounts includes a postpaid account and a prepaid account.

14. The system of claim 1, wherein at least one of the plurality of accounts has a usage limit; and is

Wherein the user's ability to use the wireless device is limited when the usage limit is exceeded.

15. A wireless device capable of communicating within a network, comprising:

a processor, memory, and an account management application resident on the memory of the wireless device for storing and maintaining a plurality of accounts;

a billing application to calculate a fee attributable to use of the wireless device; and

a user interface for allowing a user to selectably determine which of a plurality of internally stored accounts to bill for while using the wireless device;

wherein the account management application and the billing application function in cooperation with each other to maintain and properly bill a plurality of internally stored accounts.

16. The wireless device of claim 15, wherein the wireless device is capable of generating or receiving data communications.

17. The wireless device of claim 15, wherein the selection of the account to be charged in the plurality of accounts is dependent on an origin or destination of the communication.

18. The wireless device of claim 15, wherein the wireless device is a mobile phone.

19. The wireless device of claim 15, wherein the account management application resides on a smart card connected to the wireless device.

20. The wireless device of claim 15, wherein the account management application resides on internal memory in the wireless device.

21. The wireless device of claim 15, wherein the billing application resides on a network.

22. The wireless device of claim 15, wherein the account management application allows the user to transfer balances between multiple accounts.

23. The wireless device of claim 15, wherein the plurality of accounts includes a postpaid account and a prepaid account.

24. The wireless device of claim 15, wherein at least one of the plurality of accounts has a usage limit; and is

Wherein the user's ability to use the wireless device is limited when the usage limit is exceeded.

25. A mobile phone, comprising:

a user interface, a processor and a memory, wherein

Both the first line and the second line are configured within the memory to generate or receive calls; and

an account management application residing on the memory of the mobile phone and configured to store and manage a plurality of internally stored accounts;

wherein a call generated or received over the first line is credited to one of the plurality of accounts and a call generated or received over the second line is credited to another of the plurality of accounts.

26. The mobile phone of claim 25, wherein the user interface allows a user to selectively determine, via the keypad, how each call generated or received by the mobile phone is billed to one of the plurality of accounts.

27. The mobile phone of claim 25, further comprising:

a billing application for calculating a charge for each call generated or received by the mobile telephone.

28. The mobile phone of claim 25, wherein the account management application resides on a smart card connectable to the mobile phone.

29. The mobile phone of claim 25, wherein the account management application resides on internal memory in the mobile phone.

30. The mobile phone of claim 27, wherein the billing application resides on an internal memory in the mobile phone.

31. The mobile phone of claim 27, wherein the billing application resides on a network.

32. The mobile phone of claim 25, wherein the plurality of accounts includes a postpaid account and a prepaid account.

33. The mobile phone of claim 25, wherein the call generated or received over the first line comprises a business call and the call generated or received over the second line comprises a personal call.

34. The mobile phone of claim 25, wherein the account management application is configured to allow the user to transfer balances between a plurality of accounts.

35. A method for tracking account activity related to usage of a wireless device, comprising:

selecting one of a plurality of accounts for use billing of a wireless device, wherein the plurality of accounts are stored and maintained internally in the wireless device;

calculating a charge to be charged to the selected account while the wireless device is in use;

causing the wireless device to be used; and

the selected account is adjusted using the calculated cost.

36. The method of claim 35, wherein the step of selecting one of the plurality of accounts further comprises:

the user is allowed to select one of the plurality of accounts through the user interface via the keypad.

37. The method according to claim 35, wherein the step of calculating the charge to be applied to the selected account is accomplished by using a billing application.

38. The method of claim 37, wherein the billing application resides on internal memory in the wireless device.

39. The method according to claim 37, wherein the billing application resides on a network.

40. The method of claim 35, wherein the wireless device is a mobile phone.

41. The method of claim 35, wherein the wireless device is capable of generating or receiving data communications.

42. The method of claim 41, wherein the step of selecting an account of the plurality of accounts to be charged further comprises:

identifying an origin or destination of the data communication;

one of the plurality of accounts to be charged is selected based on the identified origin or destination of the voice or data communication.

43. The method of claim 35, wherein one of the internal accounts has a credit limit and the use of the wireless device is limited when the credit limit is exceeded.

44. The method according to claim 35, wherein said step of treating,

wherein one of the internal accounts has a prepaid account and the use of the wireless device is limited when the prepaid account is exhausted.

45. A method of tracking account activity by a mobile phone having a first line and a second line both configured to make or receive calls, comprising:

allocating a first account stored internally for a call generated or received through a first line;

assigning a second account stored internally for calls made or received over the second line, wherein the first and second accounts are maintained on the mobile phone;

generating or receiving a call over the first or second line;

calculating a fee to be paid for the call; and

the first account or the second account is adjusted based on a fee calculated depending on which of the first and second lines the call was made or received.