Abstract:
In the method, the receipt or lack thereof of a number select code from a mobile station forms the basis for selecting a calling number from multiple calling numbers associated with the mobile station. The number select code may directly or indirectly identify a calling number.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of wireless communication, and more particularly, to a method of selecting a calling number for a mobile station from multiple calling numbers associated with the mobile station. 
     2. Description of Related Art 
     Typically, a mobile station has a single calling number associated therewith. Billing and operation features for the mobile station are generally associated with the mobile station based on the calling number. Examples of operation features are call waiting, call forwarding, voice mail, caller identification, etc. 
     Because mobile stations have a single calling number associated therewith, users of mobile stations (e.g., mobile phones) often require multiple mobile stations. For instance, a single user may have a first mobile phone for business purposes, and a second mobile phone for personal use. The user requires two mobile phones because the user wants different billing programs and operation features depending on whether a mobile phone is being used for business or personal purposes. Because only one calling number is associated with a mobile station, only one set of billing programs and one set of operation features are associated with the mobile station. 
     Accordingly, proposals for associating multiple calling numbers with a single mobile station have been made. In these proposals, the multiple calling numbers are stored at a mobile switching center and associated with a mobile station based on a unique identifier for the mobile station (e.g., the mobile identification number or MIN). However, these proposals have failed to provide a simple method for selecting which of the multiple calling numbers should be used for a call originating at the mobile station. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a method of selecting a calling number for a mobile station from multiple calling numbers associated with the mobile station. 
     In one embodiment, the calling numbers associated with a mobile station each correspond to a different zone of operation for the mobile station, and each calling number has a different number select code associated therewith. When a call origination request is received, it is determined whether a number select code has been received. If so, the calling number associated with the number select code is used to process the call origination request. If a number select code is not received, the location of the mobile station is determined, and the calling number corresponding to the zone including the mobile station is used to process the call origination request. 
     In another embodiment, each calling number has a different number select code associated therewith, and one of the calling numbers associated with the mobile station is set as a default calling number. When a number select code is received, the calling number associated with the number select code is used to process the call origination request. If a number select code is not received, the default calling number is used to process the call origination request. 
     In a further embodiment, the user of a mobile station directly or indirectly chooses one of the calling numbers associated with the mobile station. This choice is transmitted from the mobile station to a mobile switching center via a base station, and used to subsequently process a call origination request. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, wherein like reference numerals designate corresponding parts in the various drawings, and wherein: 
     FIG. 1 illustrates a portion of a wireless communication system; 
     FIG. 2 illustrates a method of selecting a calling number for a mobile station from multiple calling numbers associated with the mobile station according to one embodiment of the present invention; 
     FIG. 3 illustrates a method of selecting a calling number for a mobile station from multiple calling numbers associated with the mobile station according to a further embodiment of the present invention; and 
     FIG. 4 illustrates a method of selecting a calling number for a mobile station from multiple calling numbers associated with the mobile station according to a still further embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates a portion of a wireless communication system. As shown, a base station  10  serves the communication needs of mobile stations, such as mobile station  8 , in a cell  12  divided into three sectors. For the sake of clarity, the directional antennas associated both with each sector of the cell  12  and the base station  10  have not been shown. The base station  10  is connected to a mobile switching center (MSC)  14 . The MSC  14  acts as an interface between several base stations (not shown), including the base station  10 , and a public telephone switching network (PTSN)  16 . Namely, the MSC  14  routes calls from the PTSN  16  to the appropriate base station, routes calls between base stations for mobile station to mobile station communication, and routes calls from a base station to the PTSN  16 . 
     Because the operation of the base station  10 , the MSC  14  and the PTSN  16  are well-known, only those operational differences necessary to implement the present invention will be described for the sake of brevity. Unlike conventional wireless communication systems, for some mobile station subscribers, the MSC  14  associates more than one calling number with a single mobile station of the subscriber. In a preferred embodiment, the MSC  14  stores an unique identifier of the mobile station, such as the mobile identification number or MIN, and associates the multiple calling numbers for the mobile station with the unique identifier. 
     Next, embodiments of the method for selecting a calling number from multiple calling numbers associated with a mobile station when the mobile station originates a call will be described with respect to FIGS. 2-4. 
     FIG. 2 illustrates a method of selecting a calling number for a mobile station from multiple calling numbers associated with the mobile station according to one embodiment of the present invention. In this embodiment, the service area for the mobile subscriber (e.g., the entire world, United States, East Coast, etc.) is divided into a number of zones of operation. Each calling number for the mobile station  8  is associated with a different one of the zones. The minimum size of a zone is limited by the method of determining the location of the mobile station  8  discussed in detail below. 
     It will be appreciated that numerous schemes exist for designing zones of operation and associating calling numbers with particular zones of operation. For the purposes of providing an example only, assume that the service area has been divided into two zones of operation, a personal zone and a business zone. Accordingly, a first and second calling number would be associated with the mobile station. The first calling number is for personal use and the second calling number is for business. The billing programs and operation features desired by the subscriber when using the mobile station  8  for personal purposes are assigned to the first calling number, and the billing programs and operation features desired by the subscriber when using the mobile station  8  for business purposes are assigned to the second calling number. 
     Furthermore, assume that the accuracy of locating a mobile station is limited to a sector, and the sector including the residence of the mobile subscriber is predetermined as a first zone. The first calling number, for personal use, and therefore the billing programs and operation features of this calling number are assigned to the first zone. The second zone is established as everywhere but the first zone, and the second calling number with associated billing programs and operation features are assigned to the second zone. 
     This scheme assumes that the subscriber generally uses the mobile station for personal purposes only when in or around his residence. However, the assumption could be just the opposite; namely, the subscriber generally uses his mobile station for business purposes only when in or around his business. Under this assumption, the second zone would be established as the sector covering the subscriber&#39;s business, and the first zone would be established as everywhere but the second zone. 
     As one skilled in the art will appreciate, the present invention is not limited to either of these schemes, the basis for these schemes (i.e., business and personal), the zones sizes, etc. 
     Furthermore, in this embodiment, each calling number has a different number select code associated therewith. For example, when the mobile station is a mobile phone, the number select code for each calling number could be “*##”, where each “#” individually represents a number between 0 and 9. 
     As shown in FIG. 2, in step S 10 , the MSC  14  receives a call origination request from the mobile station  8  via the base station  10 . The call origination request includes the unique identifier of the mobile station  8  and the number being called by the mobile station  8 . The number being called by the mobile station  8  could also include a number select code for one of the calling numbers associated with the mobile station  8  as a prefix. Using the unique identifier of the mobile station  8 , the MSC  14  accesses the calling numbers for the mobile station  8 . 
     Then, in step S 12 , the MSC  14  determines if a number select code was received as part of the call origination request. If not, then in step S 14 , the MSC  14  determines the location of the mobile station. Numerous methods exist for determining the location of a mobile station, and the method used determines the precision of the location measurement. 
     For instance, for the mobile station  8  in cell  12 , the MSC  14  knows the mobile station  8  is in or around cell  12  because the mobile station  8  is in communication with the base station  10 . Furthermore, depending on which set of directional antennas are receiving signals from the mobile station  8 , the base station  10  knows the sector in which the mobile station  8  is in or around, and the base station  10  can communicate this information to the MSC  14  (hereinafter, this location determining method will be referred to as the “sector location method”). 
     If a more specific location measurement is desired, the MSC  14  uses known triangulation methods to determine the precise location of the mobile station  8 . Alternatively, if the mobile station  8  is equipped with a global position sensor (GPS), the precise location of the mobile station  8  is determined based on the position information generated by the GPS and sent to the base station  10  by the mobile station  8 . 
     As one skilled in the art will appreciate, the method of locating the mobile station determines the minimum size of a zone. 
     Returning to FIG. 2, after determining the location of the mobile station  8  in step S 14 , the MSC  14  selects the calling number corresponding to the zone in which the mobile station  8  is located, and uses the selected calling number to process the call origination request. 
     If, in step S 12 , a number select code is received in the call origination request, the MSC  14 , in step S 18 , selects the calling number associated with the received number select code, and uses the selected calling number to process the call origination request. 
     FIG. 3 illustrates a method of selecting a calling number for a mobile station from multiple calling numbers associated with the mobile station according to another embodiment of the present invention. In this embodiment, a different number select code is associated with each calling number, and one of the calling numbers is predetermined as a default. 
     As shown in FIG. 3, in step S 30 , the MSC  14  receives a call origination request from the mobile station  8  via the base station  10 . The call origination request includes the unique identifier of the mobile station  8  and the number being called by the mobile station  8 . The number being called by the mobile station  8  could also include a number select code for one of the calling numbers associated with the mobile station  8  as a prefix. Using the unique identifier of the mobile station  8 , the MSC  14  accesses the calling numbers for the mobile station  8 . 
     Then, in step S 32 , the MSC  14  determines if a number select code was received as part of the call origination request. If not, then in step S 34 , the MSC  14  selects the default calling number, and uses the selected calling number to process the call origination request. If, in step S 32 , a number select code is received in the call origination request, the MSC  14 , in step S 34 , selects the calling number associated with the received number select code, and uses the selected calling number to process the call origination request. 
     The methods described above with respect to FIGS. 2-3 provide the advantage that existing mobile stations do not need to be redesigned or reprogrammed to implement the present invention. Instead, only the service provider needs to perform modifications. FIG. 4, however, illustrates another embodiment of the present invention that provides greater flexibility in the selection of calling numbers, but requires modifications to existing mobile stations to implement the invention. Namely, the mobile station includes a mechanism by which the user of the mobile station can select a calling number for use during call origination. 
     In a preferred embodiment, the mobile station  8  includes a program that provides the user with a menu of the calling numbers. Through key entry, the user selects one of the calling numbers for use during call origination in step S 50 . The mobile station  8  then transmits the unique identifier and a code designating the selected calling number to the MSC  14  via the base station  10  in step S 52 . The MSC  14  will then process a subsequent call origination requests from the mobile station  8  using the calling number designated by the received code. 
     Instead of directly identifying a calling number, the user could indirectly choose the calling number based on a desired use of the mobile station. For instance, the menu could provide the user with choices such as personal, business, etc. Choosing a particular use indirectly sets the calling number. Instead of being use based, the indirect calling number choice may have another basis, such as location, (e.g., identifies a zone of operation). 
     The method of FIG. 4 gives the mobile station user great flexibility in choosing a calling number, and eliminates the need for the user to remember number select codes and their correspondence to calling numbers of the mobile station  8 . 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications are intended to be included within the scope of the following claims.