Abstract:
The present invention provides a method to allow mobile stations in a wireless communications system to act as extension units to each other. A first mobile station receives a call request. The first mobile station determines if extension functionality is enabled. If wireless extension functionality is enabled, the first mobile station determines which other mobile stations are in the extension member list. The first mobile station alerts other mobile stations in the extension list. The other mobile stations return instructions as to the disposition of the call. Those accepting the call are bridged onto the call and notified when the call ends. Inclusion of determination of the geographical location of other mobile stations allows call alerting to be restricted to mobile stations within a predetermined geographic location.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    The present application is related to application Ser. No. ______ , entitled “METHOD OF PROVIDING NETWORK-BASED WIRELESS EXTENSION SERVICE”. The above patent application is filed on the same day as the present application, assigned to the assignee of the present application, and incorporated by reference herein.  
         FIELD OF THE INVENTION  
         [0002]    This invention relates generally to the field of wireless communication systems, and more particularly utilizating wireless phones as extension phones for each other.  
         BACKGROUND OF THE INVENTION  
         [0003]    Existing analog wireline extensions allow multiple wireline phones to be alerted by an incoming call. In addition, multiple of these wireline extensions can participate in a single call. one limitation to wireline extension phones is that once a phone is engaged in a call, the other phones can participate in the ongoing call but cannot participate in a different call.  
           [0004]    In current wireless communication systems, no such extension capability exists. A call destined for a mobile station alerts only that station and only that station can participate in the session.  
           [0005]    Therefore, a need exists for a method and apparatus that allows mobile stations to be simultaneously alerted when a call is destined for a member of the group. Further, a need exists for a method that allows multiple wireless phones to be involved in such a call. In addition, a need exists for a method that allows multiple mobile stations to participate in a single call.  
         BRIEF SUMMARY OF THE INVENTION  
         [0006]    The present invention provides a method for providing extension functionality to multiple mobile stations. The users of the mobile stations are all alerted when a call is destined for any of the extension members. Each user can then decide whether to join the call. In an exemplary embodiment of the present invention, each mobile station maintains its individuality and can initiate or receive calls without invoking the extension functionality. In a further exemplary embodiment, via the use of physical location of the mobile stations, only extension members within a certain geographical location will be afforded extension functionality.  
           [0007]    In accordance with an exemplary embodiment of the present invention, a mobile station stores a list of identities of the members of the extension group. These identities can be E.164 numbers or any other unique identifiers. When alerting of an incoming call arrives at the mobile station, the mobile station locally bridges the call to a “one-to-many” call and causes alerting to be sent to other extension members.  
           [0008]    Further, the mobile station can perform a location determination on the extension members and only bridge the call to other extension members located within a predefined distance of the called mobile station. A unique alerting display is used at the other extension mobile stations to indicate that this is an extension call and not a direct call to those other mobile stations. Extension functionality can be disabled at each mobile allowing completely independent operation.  
           [0009]    Advantageously, such an arrangement gives mobile station users the functionality of extension phones and allows the mobile stations to also be used in an independent mode. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 depicts a communication system in accordance with an exemplary embodiment of the present invention.  
         [0011]    [0011]FIG. 2 depicts a flow chart of a method for processing a call request in a first mobile station in accordance with an exemplary embodiment of the present invention.  
         [0012]    [0012]FIG. 3 depicts a flow chart of a method for processing, in mobile stations that are members of an extension group, a call request generated by the extension functionality in accordance with an exemplary embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]    [0013]FIG. 1 depicts a communication system  100  in accordance with an exemplary embodiment of the present invention. Communication system  100  includes base stations  140  and  150  and wireless core network elements  160 . Wireless core network elements  160  comprise known functions necessary to operate and maintain a wireless communication network. Communication system  100  is coupled to external networks  195 , which can include other wireless networks and/or a Public Switched Telephone Network (PSTN).  
         [0014]    Base stations  140  and  150  are coupled to wireless core network elements  160  via links  141  and  151  and provide over-the-air communications with a plurality of mobile stations, such as first mobile station  110  and second mobile station  120 . It should be understood that communication system  100  can include a plurality of wireless core network elements and base stations. Only a single block of wireless core network elements  160  and two base stations  140  and  150  are depicted in FIG. 1 for clarity.  
         [0015]    In the embodiment depicted in FIG. 1, first mobile station  110  and second mobile station  120  are coupled to and communicating with communication system  100 . It should be understood that in an actual wireless network a plurality of mobile stations are coupled to the network via base stations. Only two mobile stations  110  and  120  are depicted in FIG. 1 for clarity. As depicted in FIG. 1, first mobile station  110  is communicating with base station  140  via an over-the-air interface. Second mobile station  120  is coupled to base station  150  via an over-the-air interface. The over-the-air interfaces can be the same or different. Also, it should be understood that first mobile station  110  and second mobile station  120  can be communicating with a single base station, such as base station  140 . Mobile station  120  preferably includes a display  130  to visually display information to a user of mobile station  120 .  
         [0016]    In an exemplary embodiment of the present invention, first mobile station  110  receives an incoming call request. The call request can originate either within the wireless communications network or from other networks  195  that interface with wireless communication network  160 , such as a Public Switched Telephone Network (PSTN). First mobile station  110  determines if extension functionality is enabled. If extension functionality is enabled, first mobile station  110  initiates wireless extension call requests to other mobile stations, such as second mobile station  120 , that are stored in an extension list locally in first mobile station  110 . The wireless extension call requests include an indication that the call request was generated by the extension functionality at first mobile station  110 .  
         [0017]    First mobile station  110  preferably can determine the geographical locations of mobile stations in the wireless extension group. First mobile station  110  may generate call requests only to other mobile stations within a predetermined geographical area. The location of the other mobile stations can be determined by first mobile station  110  using techniques such as cell and sector, time of arrival, and other similar location-finding techniques. These techniques rely on cooperation on elements such as base stations  140  and  150  and wireless core network elements  160  with the mobile stations in the wireless extension group.  
         [0018]    An exemplary embodiment of the present invention includes determination of the locations of the mobile phones in the extension list. Without loss of generality or functionality, the called mobile station can, via existing means, request that the location step be bypassed.  
         [0019]    The following are three representative examples for the use of geographical information used in extension functionality. First, extension service can be offered to mobile stations on a corporate campus. That is, only mobile stations located in the workplace at a given time would be offered extension service. Second, all mobile stations located at or near a residence can be offered extension service. In this way personal calls can be shared among mobile stations at the residence without interrupting mobile stations away from the residence. Finally, there can be no geographical limitations at all. All mobile stations in the extension list are alerted.  
         [0020]    Upon receipt of the extension call request, second mobile station  120  alerts the user of the incoming extension call request. This alerting preferably occurs if the user is idle or is engaged in another call. Mobile station  120  displays call request information on display  130 . The information indicates to the user that this is an extension call. Responsive to information on display  130 , the user can specify, such as by depressing a keypad key, actions to be taken. In the preferred embodiment of the present invention, the user can specify the appropriate action to be taken by depressing a keypad key, but can alternately specify the appropriate action by issuing a voice command or any other method of inputting a command to second mobile station  120 . Second mobile station  120  then informs first mobile station  110  via a call response of the desired action.  
         [0021]    After receiving the call responses from the mobile stations that are extension members (in a manner analogous to that presented for mobile station  120 ), first mobile station  110  bridges the call to the mobile stations that are extension members, represented by other mobile station  120 , which have indicated, within a predetermined time, that they would accept the extension call. If no other such stations accept the call, the call is completed as if it were only directed to mobile station  110 . After the bridged extension call ends, first mobile station  110  notifies the other extension mobile stations that participated in the wireless extension call that the call has ended.  
         [0022]    [0022]FIG. 2 depicts a flow chart  200  of a method for processing a call request in first mobile station  110  in accordance with an exemplary embodiment of the present invention.  
         [0023]    First mobile station  110  receives ( 201 ) a call request. This call request can be for a voice, data, or multimedia call.  
         [0024]    First mobile station  110  determines ( 202 ) if the extension functionality is enabled. The extension functionality can be enabled by the user of first mobile station  110 . This can be done by methods such as depressing a keypad key. Extension functionality is preferably stored locally in mobile station  110 . If the extension functionality is not enabled, fist mobile station  110  completes ( 203 ) the call normally, and the processing ends ( 299 ).  
         [0025]    If the extension functionality is enabled as determined at step  202 , first mobile station  110  initiates ( 204 ) call requests to other mobile stations that are on the extension list stored locally in first mobile station  110 . In the process of initiating the call requests, first mobile station  110  may also determine the location of other mobile stations in the extension list and only send call requests to extension list mobile stations that are in a predetermined geographic area. The processing performed by a second mobile station  120  is depicted in FIG. 3.  
         [0026]    Turning now to FIG. 3, FIG. 3 depicts a flowchart  300  of a method for processing in other mobile stations a call request generated by the extension functionality in accordance with an exemplary embodiment of the present invention. The other mobile stations in the wireless extension group receive ( 301 ) an indication of an incoming extension call.  
         [0027]    Each mobile station alerts ( 302 ) the users of the mobile station of the incoming call. The alerting can be done visually, audibly, or via vibration. For example, the alert can be visual by lighting a light on the display of the mobile station, displaying an icon on the display of the other mobile station, or any other means of displaying information on the display to alert the user of the incoming call request. An alert can also be audible, such as a beep, tone, or tune played on the mobile stations. This audible alerting can be done via existing means currently used to cause tones/ringing sequences to be played at a mobile station.  
         [0028]    The mobile station displays ( 303 ) an indication that this call is a wireless extension call. This is accomplished via any one of the existing means to display information on a mobile station, such as an icon on the display.  
         [0029]    The mobile station accepts ( 304 ) instructions as to the desired disposition of the call. The user of each wireless extension phone can decide to accept the call or reject the call. If the user accepts the call request, the accepting mobile station will be bridged into the call by the first mobile station. If the user of the wireless extension phone does not respond within a predetermined period of time, the wireless phone is treated as if the call was rejected.  
         [0030]    Each wireless extension mobile station informs ( 305 ) the first mobile station of the disposition of the call request.  
         [0031]    Returning now to FIG. 2, first mobile station  110  receives ( 205 ) call responses from the mobile stations in the wireless extension group. If first mobile station  110  does not receive a response from a wireless extension member within a predetermined amount of time, first mobile station treats the lack of a response as the equivalent of a rejection from that wireless extension member. The predetermined period of time can be set to any time period that makes the lag time of the call responses acceptable to a user.  
         [0032]    First mobile station  110  bridges ( 206 ) the call to the other mobile stations which indicated instructions to accept the call in the call response. In this manner the calling phone, the called wireless phone, and the accepting members of the wireless extension group are bridged together on a single phone call.  
         [0033]    The call then proceeds as a multiparty call. When the callers wish to end the call, links are dropped as first mobile station  110  notifies ( 207 ) the other mobile stations that the call has ended. Processing of the call then ends ( 299 ).  
         [0034]    The present invention thereby provides a method for providing extension capabilities to wireless mobile stations. By using the present invention, the user can be given the same functionality as is available with wireline extension phones. When coupled with the ability of determining the geographical location of other mobile stations, employee group members located at a corporate campus can be alerted to an incoming call, family members located at or near the residence can be alerted to an incoming call, or no geographical limitation may be imposed, thereby alerting all extension group members of an incoming call.  
         [0035]    While this invention has been described in terms of certain examples thereof, it is not intended that it be limited to the above description, but rather only to the extent set forth in the claims that follow.