Abstract:
The present invention provides a system and method for reconnecting a dropped mobile telephone call without input from the dropped party or the remaining party. In accordance with the present invention, the system determines that a call has been terminated abnormally, possibly due to an unsuccessful transition between cell towers. The system then initiates reconnection of the dropped party with the remaining party with no input from either party. The remaining party may optionally hear a recorded message while the call is reconnected.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     None. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     None. 
     TECHNICAL FIELD 
     The present invention relates to handling dropped mobile telephone calls. More particularly, the present invention relates to a system and method for reconnecting dropped mobile telephone calls using an automatic callback of the dropped party. 
     BACKGROUND OF THE INVENTION 
     Mobile telephones work well within the range of a single cell tower. But when the user&#39;s movement necessitates a change from one cell tower to a new cell tower, calls may be dropped during the transition between two towers. To solve the root cause of this dilemma requires improving the transition from one cell tower to another cell tower, an ongoing process for mobile telephone service providers. As cell tower transitions are improved, the present invention lessens the undesired impact of dropped calls by providing a service within the communication network that automatically reconnects the dropped call. 
     The same reconnection service may be useful in other wireless networks, such as 802.11b or 802.11g networks connecting into wire-based communication networks. These wireless links could be reconnected in a similar manner as the mobile telephone call in the event that the wireless link was terminated abnormally during a transition between two wireless access points. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system and a method to automatically reconnect a dropped mobile call when the call is terminated abnormally, as when a mobile telephone call is interrupted by an unsuccessful transition between two cell towers. Optionally, a message may be provided to the remaining party while the reconnection is in progress. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The present invention is described in detail below with reference to the attached drawing figures, wherein: 
         FIG. 1  illustrates a communication architecture in accordance with the present invention for a mobile telephone connection; 
         FIG. 2  illustrates a communication architecture in accordance with the present invention for an abnormally terminated mobile telephone connection; 
         FIG. 3  illustrates a system architecture in accordance with the present invention for implementing a reconnection service; 
         FIG. 4  illustrates a method in accordance with the present invention for implementing a reconnection service; and 
         FIG. 5  illustrates a further method in accordance with the present invention for implementing a reconnection service. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides a system and method for reconnecting a mobile telephone call when the call is terminated abnormally. An abnormal termination may occur, for example, when a mobile telephone is transferred from one cell tower to another cell tower during a call. While a transition from one cell tower to another cell tower is a common cause of an abnormal termination, the present invention may be applied to all abnormal terminations, not just those caused by tower transitions. 
       FIG. 1  illustrates a communication architecture  100  for a mobile telephone connection. A mobile voice communication device  110  may be connected to a base transceiver station (BTS)  120  via a wireless connection using, for example, radio waves. One skilled in the art will appreciate that mobile voice communication device  110  may possess capabilities beyond voice communication, such as wireless data capabilities and/or data management capabilities. BTS  120  is connected to a base station controller (BSC)  130 . BSC  130  may connect to an application server  140 . Application server  140  may comprise a computer server executing an operating system such as Microsoft Windows or a Unix operating system such as HP-UX, IBM AIX, Sun Solaris, although any computer operating system may be used. In the scenario where the reconnection service is offered as a subscription service, subscriber database server  180  may optionally connect to application server  140  to provide subscriber information to application server  140  in order to determine if the user is subscribed to the reconnection service. Subscriber database server  180  may comprise a computer server executing an operating system such as Microsoft Windows or a Unix operating system such as HP-UX, IBM AIX, Sun Solaris, although any computer operating system may be used. BSC  130  may connect to a mobile switching center (MSC)  150 , which may also be referred to as a mobile serving switch. MSC  150  may connect to a telephone network  160 . Telephone network  160  may be a circuit-based network, such as a public switch telephone network (PSTN), or a packet-based network. Telephone network  160  may connect to a voice communication device  170 . Voice communication device  170  may be, for example, a mobile or landline telephone. 
       FIG. 2  illustrates a communication architecture  200  for an abnormally terminated mobile telephone connection. When a telephone call is terminated, BSC  130  provides a termination code to MSC  150  indicating the type of termination. If one of the two parties voluntarily disconnects, the call is designated with a normal termination code. If the call is interrupted without either party voluntarily disconnecting, the call is designated with an abnormal termination code. When mobile voice communication device  110  is abnormally disconnected from the architecture of  FIG. 1 , mobile voice communication device  110  may be referred to as the dropped party. In  FIG. 2 , the terminated segment  210  occurs between mobile device  110  and BTS  120 . BTS  120  may be connected to BSC  130 , which may be connected to application server  140 . BSC  130  may be further connected to MSC  150 . MSC  150  may be connected through telephone network  160  to voice communication device  170 . Voice communication device  170  becomes the remaining party of an abnormally terminated call. As in  FIG. 1 , voice communication device  170  may be a mobile or landline telephone. Either BSC  130  or application server  140  may determine if the connection was terminated abnormally and if terminated segment  210  is controlled by MSC  150 . BSC  130  or application server  140  may also determine if the dropped party  110  subscribes to the reconnection service prior to initiating an action to reconnect dropped party  110 . In the scenario where the reconnection service is offered as a subscription service, subscriber database server  180  may optionally connect to application server  140  to provide subscriber information to application server  140  in order to determine if the user is subscribed to the reconnection service. BSC  130  or application server  140  may also play a recorded message to remaining party  170  while reconnecting dropped party  110  to remaining party  170 . The recorded message may indicate that remaining party  170  should hold on the line while dropped party  110  is reconnected. The recorded message may also contain advertisements, informational content, promotional material or public service announcements. The connection may be restored between the original BTS  120  and dropped party  110 . Alternatively, the connection may be restored between a different BTS and dropped party  110 , as in the case where the abnormal termination resulted from a transition between two towers. 
     Referring now to  FIG. 3 , a system architecture  300  for implementing the reconnection service of the present invention is described. The communication network  310  may contain services such as announcement service  320  and reconnection service  330 . The communication network  310  may be configured similarly to the network in  FIG. 1 . Remaining party  170  is connected to communication network  310 . Announcement service  320  may play a recorded message to remaining party  170  while reconnection service  330  is reconnecting dropped party  110 . The recorded message may indicate that remaining party  170  should hold on the line while dropped party  110  is reconnected. The recorded message may also contain advertisements, informational content, promotional material or public service announcements. Communication network  310  may be packet-based or circuit-based at its core. At least one end of communication network  310  is equipped to connect mobile telephones as in  FIG. 1 . 
     Referring now to  FIG. 4 , a method  400  in accordance with the present invention for implementing the reconnection service is illustrated. Method  400  may be performed in software hosted by BSC  130  or application server  140  illustrated in  FIG. 1 . In step  410  of method  400 , BSC  130  or application server  140  determines if the mobile telephone call terminated abnormally. A call may be said to have terminated abnormally if either party did not voluntarily disconnect from the call. If the call did terminate normally, method  400  terminates at the end process step  430 . If the call terminated abnormally, BSC  130  or application server  140  determines if mobile serving switch  150  controlled terminated segment  210  in step  420 . If mobile serving switch  150  did not control terminated section  210 , method  400  terminates at end process step  430 . If mobile serving switch  150  did control the terminated section, dropped party  110  is reconnected to remaining party  170  in step  440 . The connection may be restored between the original BTS  120  and dropped party  110 . Alternatively, the connection may be restored between a different BTS and dropped party  110 , as in the case where the abnormal termination resulted from a transition between two towers. 
     Referring now to  FIG. 5  a further method  500  in accordance with the present invention for implementing the reconnection service is illustrated. Method  500  may be performed in software hosted by BSC  130  or application server  140  illustrated in  FIG. 1 . In step  510  BSC  130  or application server  140  determines if the mobile telephone call terminated abnormally. A call may be said to have terminated abnormally if either party did not voluntarily disconnect from the call. If the call did terminate normally, method  500  terminates at the end process step  530 . If the call terminated abnormally, BSC  130  or application server  140  determines if mobile serving switch  150  controlled terminated segment  210  in step  520 . If mobile serving switch  150  did not control terminated section  210 , method  500  terminates at end process step  530 . If mobile serving switch  150  did control the terminated section, BSC  130  or application server  140  may optionally check if dropped party  110  subscribes to the reconnection service in step  540 . If there is no subscription, method  500  terminates at end process step  530 . If dropped party  110  subscribes to the reconnection service, dropped party  110  is reconnected to remaining party  170  in step  550 . The connection may be restored between the original BTS  120  and dropped party  110 . Alternatively, the connection may be restored between a different BTS and dropped party  110 , as in the case where the abnormal termination resulted from a transition between two towers. Optionally, in step  560  a recorded message is played to remaining party  170  while the reconnection is in progress. This recorded message may indicate that remaining party  170  should hold the line while dropped party  110  is reconnected. The recorded message may also contain advertisements, informational content, promotional material or public service announcements. 
     Methods and systems, such as those described above, could also be applied to wireless networks, such as 802.11b or 802.11g networks. One skilled in the art would recognize that a wireless access point connected to a packet-based network could be analogous to BTS  120  connected to telephone network  160 . In much the same way that a mobile telephone experiences a dropped call when transitioning between two cell towers, a wireless device may experience a dropped connection when transitioning between two wireless access points. The present invention could be used to reconnect the wireless device through the original or new wireless access point without action on the part of the dropped party. The recorded message may, in this case, be a text message displayed on the wireless device, but providing the same capabilities as described above.