Abstract:
The present invention provides a method for contacting a wireless user who subscribes to several bearer services. The wireless user may be active on only a single bearer service at any given time. The present invention discloses a method for contacting the wireless user by sending alert messages over each of the wireless bearer services in turn until the user is contacted.

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a method for contacting a subscriber to several different wireless bearer services at a wireless communicator when the wireless communicator can only be active on one bearer service at a time. 
     BACKGROUND OF THE INVENTION 
     As the availability and use of wireless communication services continues to expand and devices have become available that can transmit and receive on several different kinds of wireless networks, it has become commonplace for individual wireless users to subscribe to more than one wireless service for use with a single wireless communicator. These wireless communication bearer services transmit and receive using different formats and methods of transmission. Due to these differences between the bearer services and physical limitations of the wireless communication device itself, the wireless communicator generally can only be active on a single bearer service at any given time. This becomes a problem when a connection or message to the subscriber is desired because it is impossible to know what bearer service to use to reach the subscriber. 
     One solution to this problem is to have the wireless communication device notify or register with a central server whenever it changes to a different bearer service and that central server can direct any incoming messages or connection requests to use the proper bearer service. This approach has several drawbacks. First, it requires additional functionality in the wireless communicator to provide support for the registration function. It also results in increased network traffic and the need for a channel to be opened between the wireless communicator and central server every time the subscriber changes the bearer service setting on the wireless communicator. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved method for contacting the wireless communicator of a subscriber who uses multiple bearer services. When a message delivery request is received, a first wireless bearer service is selected from the group of bearer services that the subscriber uses, and a delivery is attempted on that bearer service. If no response is received from the wireless communicator after a certain amount of time has elapsed, a second bearer service is selected and a delivery is attempted on that bearer service. The process is repeated until a delivery is successful or until all of the subscriber&#39;s bearer services have been attempted without success. 
     The present invention presents a solution to the problem of contacting a wireless user who subscribes to several bearer services that does not require additional functionality in the communicator or a registration connection every time the subscriber switches bearer services. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a wireless network such as may be used with an embodiment of the present invention. 
     FIG. 2 is a flowchart illustrating one possible implementation of the method of the present invention. 
    
    
     DETAILED DESCRIPTION 
     In an embodiment shown in FIG. 1, the method of the present invention is triggered by receipt at central server  102  of a message delivery request from network  101  to wireless communicator  103 . Network  101  could be the Public Switched Telephone Network (PSTN), the Internet, a Private Branch Exchange (PBX), or any other communication network. The message received by central server  102  contains information identifying a particular individual who subscribes to multiple bearer services. Using this identifying information, central server  102  retrieves a list of the subscriber&#39;s bearer services from database  107 . Bearer service  104  is selected from the list and central server  102  transmits a message delivery request over bearer service  104  to attempt to contact wireless communicator  103 . If wireless communicator  103  is active on bearer service  104 , it will respond to the message delivery request and central server  102  can complete the desired delivery from network  101 . After a certain amount of time elapses with no response from wireless communicator  103 , central server  102  will select bearer service  105  from the list and attempt a message delivery over bearer service  105  to wireless communicator  103 . If wireless communicator  103  is active on bearer service  105 , it will respond to the message delivery request and central server  102  can complete the desired delivery from network  101 . If wireless communicator  103  is not active on bearer service  105 , after a certain amount of time elapses central server  102  will timeout the attempt and select bearer service  106  from the list. The process of attempting message delivery repeats for each of the bearer services that a user has subscribed to until wireless communicator  103  is successfully contacted or all of the bearer services in the list have been attempted and wireless communicator  103  has failed to respond on any of them. 
     If all of the attempts fail, then the process may start over with the first bearer service in the list, the message delivery request may be stored to attempt a delivery at a future time, or server  102  can simply notify the requestor that the subscriber is unreachable. The determination of what post-failure procedure to implement may also be dependent on the type of message delivery attempted. For example, a request for an email message or fax may be stored for later transmittal, while a request for an urgent page may be tried continuously, and a request for a voice connection may be routed to a voice mail system. A stored message delivery request could also be sent the next time the subscriber connects to a bearer service in order to place a call. 
     The message delivery request that is received may take many forms, such as a paging message to be transmitted to the subscriber, a computer generated information message such as a stock quote or a sports score, a message indicating an update to the subscriber&#39;s schedule, contact list/address book or other Personal Information Manager (PIM) information, an email message, a fax, or a request for a voice connection. 
     The order in which the bearer services are tried may be customized. The present invention can be implemented such that the bearer services are always attempted in a particular order based on the subscriber&#39;s or service provider&#39;s preferences. Alternatively, a message delivery could be first attempted on the bearer service that the subscriber was most recently successfully contacted on. Another alternative implementation would track the success rate of message delivery attempts on the various bearer services and attempt message delivery on the bearer services in an order based on this previous success rate. For example, if the subscriber was reached 60% of the time on bearer A, 10% of the time on bearer B, and 30% of the time on bearer C, the order in which the bearer services would be attempted would be A, C, B. 
     The bearer services could include any digital or analog method used to communicate with wireless devices including Cellular Digital Packet Data (CDPD), IS-130/135, and Generic UDP Transport Service (GUTS) over IS-136. The bearer services could also be satellite or ground based. 
     The wireless communicator is not limited to cellular telephones, but may be any wireless communication device including pagers, Personal Digital Assistants (PDA), and portable computing devices. 
     FIG. 2 is a flow chart illustrating one possible implementation of the method of the present invention. A message delivery request that contains information identifying the subscriber or wireless device to be contacted is received by a server providing the service of the present invention (step  201 ). The server uses the identifying information in the request to retrieve a corresponding list of bearer services from a database (step  202 ). The server then selects the first bearer service from the list and transmits a message delivery request via that bearer service (step  203 ). The server then waits a predetermined amount of time for a response to the message delivery request (step  204 ). If a response is received the server completes the delivery between the original requester and the wireless device (step  205 ,  206 ). If no response is received the server then checks to see if a message delivery has been attempted on all the bearer services (step  207 ). If all the bearer services have been tried then the server stores the message delivery request for transmission later (step  209 ). If not, then the server transmits a message delivery request on the next bearer service and repeats the process (step  208 ). 
     The present invention is not limited to the specific embodiments described. It is expected that those skilled in the art will be able to devise other implementations that embody the principles of the present invention and remain within its scope.