Patent Publication Number: US-6711609-B2

Title: Method and apparatus for synchronizing an email client on a portable computer system with an email client on a desktop computer

Description:
RELATED APPLICATIONS 
     This application is a continuation of Ser. No. 08/790,622, “Method and Apparatus for Synchronizing an Email Client on a Portable Computer System With an Email Client on a Desktop Computer,” filed on Jan. 29, 1997, by inventors Monty Boyer and Joseph Sipher, now U.S. Pat. No. 6,401,112. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of portable computers systems. Specifically, the present invention discloses a systems for synchronizing an email client on a portable computer system with an email client on a desktop computer system. 
     BACKGROUND OF THE INVENTION 
     Personal computer systems have become common tools in modern society. One of the most important uses for personal computers is electronic mail (email). Personal computer users use email to send notes and computer files to other computer users. 
     Many personal computer users also use small portable palmtop computer systems such that the personal computer user can carry important personal information. To store the important personal information, palmtop computer systems usually provide Personal Information Management (PIM) applications such as an address book, a daily organizer, and a To-Do list applications. 
     In addition to the Personal Information Management (PIM) applications, it would be desirable to have an email application on the palmtop computer system. The email application would allow the user to send and receive email messages using the palmtop computer system. 
     Although an email application on palmtop computer system would be very useful, such an application can create problems. For example, would incoming email arrive on the desktop personal computer system, the portable computer system or both? Furthermore, if the user deleted an email message on one of the two computer systems, should that email message appear on the other computer system? Thus, it would be desirable to have an email application for a palmtop computer system that is completely in synchronization with an email application on a desktop personal computer system. 
     SUMMARY AND OBJECTS OF THE INVENTION 
     It is therefore an object of the present invention to provide a palmtop computer system that is fully integrated with common email systems used by desktop personal computers. To accomplish this goal, the present invention introduces an email client for the portable computer system and an email synchronization conduit for a desktop personal computer system. 
     The email client for the portable computer system allows the user to view incoming email messages. The email client on the portable computer system also allows the user to compose outgoing email messages. 
     The email synchronization conduit on the desktop personal computer system is responsible for synchronizing the state of the portable computer email client with an email client on a personal computer system. After a synchronization event, the email synchronization conduit ensures that the email state on the portable computer system exactly matches the email state on the desktop personal computer system. For example, if an email message is deleted on email client of the portable computer system then a matching copy of that email message will be deleted from the desktop personal computer system. Similarly, if an email message is deleted on the email client of the desktop personal computer system then that email message will be deleted from the portable computer system. By keeping the email state of the two different computer systems in exact synchronization, the user can switch between the email client on the portable computer system and the email client on the desktop personal computer system without missing a message or reading a redundant message. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The objects, features, and advantages of the present invention will be apparent from the following detailed description of the preferred embodiment of the invention with references to the following drawings. 
     FIG. 1 a  illustrates a portable computer system and a personal computer system equipped with a cradle for synchronizing with the portable computer system. 
     FIG. 1 b  illustrates a block diagram that depicts the software architecture for synchronizing information on the portable computer system with information on a desktop personal computer system. 
     FIG. 2 a  illustrates a block diagram that depicts the software architecture for synchronizing email on the portable computer system with email on the desktop personal computer system using the Microsoft® MAPI protocol. 
     FIG. 2 b  illustrates a block diagram that depicts the software architecture for synchronizing email on the portable computer system with email on the desktop personal computer system using the Lotus® VIM protocol. 
     FIG. 3 illustrates a flow diagram that describes how email on the desktop personal computer system is synchronized with email on the portable computer system. 
    
    
     DETAILED DESCRIPTION 
     Methods and apparatus for implementing a palmtop computer system that is well integrated with a personal computer system is disclosed. In the following description, for purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required to practice the present invention. In other instances, well-known circuits and devices are shown in block diagram form to avoid obscuring the present invention. 
     Basic Synchronization 
     FIG. 1 a  illustrates a portable computer system  130  that communicates and synchronizes information with a personal computer system  110 . To synchronize the information in the two computer systems, a user places the portable computer system  130  into the cradle  120  and presses synchronization button  125 . The synchronization button  125  activates a synchronization program on the portable computer system  130 . The synchronization program on the portable computer system  130  communicates with a peer synchronization program on the personal computer system  110 . The two synchronization programs synchronize the information on the two computer systems. 
     FIG. 1 b  illustrates a block diagram of the software components that perform the synchronization of the two computer systems. In FIG. 1 b , the portable computer  160  has two different programs, program A and program B, that execute on the portable computer  160 . Program A and program B use a common database  163  to store their data. 
     Referring to FIG. 1 b , a synchronization cradle  180  is illustrated below the portable computer  160 . The synchronization cradle  180  has a button  185  that activates a synchronization Program (HotSync)  161  in the portable computer system  160 . When activated, the HotSync Program  161  communicates with the peer synchronization program (HotSync Manager)  170  in the personal computer  150 . The HotSync Manager  170  operates by executing a series of conduit programs such as conduit program A and conduit program B illustrated in FIG. 1 b . Each conduit program is used to synchronize the information associated with a particular program on the portable computer system. Conduit programs can also perform additional tasks such as software installation. A full description of the synchronization architecture can be found in the U.S. patent application entitled “Extendible Method and Apparatus for Synchronizing Multiple Files On Two Different Computer Systems” having Ser. No. 08/542,055, filed on Oct. 13, 1995, now U.S. Pat. No. 5,884,323. 
     In FIG. 1 b , conduit program A and conduit program B are used to synchronize the data for application program A and application program B on the portable computer  160  respectively. The HotSync Manager  170  communicates with the HotSync Program  161  in order to access the database  163  on the portable computer  160 . The necessary records from of the database  163  are copied to the personal computer such that the conduit programs on the personal computer can process the records. In the example of FIG. 1 b , the records from database  163  that are associated with application program A and application program B are copied into the personal computer and then reconciled with databases A and database B by conduit A and conduit B respectively. After the records have been synchronized, the synchronized records are written back to the database  163  on the portable computer system  160 . 
     Email Synchronization 
     Synchronizing email information is not as simple as synchronizing a simple database such as an address list. To fully describe how the present invention synchronizes an email client program on a desktop personal computer system with an email client program on a portable computer system, a detailed description is provided with reference to FIGS. 2 a ,  2   b , and  3 . 
     FIG. 2 a  illustrates the general software architecture for synchronizing an email client program on a desktop personal computer system with an email client program on a portable computer system. In the example of FIG. 2 a , the email client program on the personal computer uses the Microsoft MAPI protocol. However, other email protocols may also be used as will be described later. 
     FIG. 2 a  illustrates a portable computer system  210  having an email client program  211 . The email client program  211  works with email records stored in the database  215 . The email client program  211  allows the user to view received email stored in the database  215 . The email client program  211  also allows the user to compose new email messages to be sent to other computer users. 
     The portable computer system requires a connection to a computer network infrastructure to receive new email and to send newly composed email messages. To connect with the computer network infrastructure, this document describes a synchronization environment wherein the portable computer is coupled to a personal computer using a serial link as depicted in FIGS. 1 a ,  1   b , and  2   a . However, many other methods of connecting the portable computer system to a personal computer system as described in the patent application “Method And Apparatus For Synchronizing A Portable Computer System With A Desktop Computer System”, filed on May 25, 1999, with Ser. No. 09/318,404, now U.S. Pat. No. 6,330,618, which is a continuation of “Method and Apparatus Using a Pass Through Personal Computer Connected to Both a Local Communication Link and a Computer Network for Identifying and Synchronizing a Preferred Computer with a Portable Computer”, filed on Jan. 30, 1997, with Ser. No. 08/792,166, now U.S. Pat. No. 6,006,274. 
     To update the email records stored in database  215 , the user can place the portable computer system  210  into a cradle coupled to a personal computer through a serial link. The user presses a syncrhonization button on the cradle to activate a HotSync Program  217  on the portable computer system  210 . The HotSync Program  217  on the portable computer system  210  communicates through the serial link with a HotSync Manager Program  231  on the personal computer system. The HotSync Manager Program  231  executes a number of conduit programs to synchronize databases including an email conduit program  233  to synchronize the email information. 
     To synchronize the email records from the portable computer system, the email conduit  233  communicates with a MAPI software layer  253  in the operating system software of the personal computer  250 . The MAPI software layer  253  provides a limited set of routines for manipulating email on an email server. Detailed information about the MAPI software layer can be found in the Microsoft Developer Network documents published by the Microsoft Corporation. 
     Referring to FIG. 2 a , a MAPI-compliant email server  280  is connected to a computer network  270  that is also coupled to the personal computer system  250 . To access the email information on the MAPI-compliant email server  280 , an application program on the personal computer  250  can issue MAPI compliant requests to the MAPI software layer  253 . The MAPI software layer  253  transmits a request packet across the computer network  270  to the MAPI compliant email server  280 . In response to the properly formatted MAPI requests, the MAPI-compliant email server  280  sends information back to the MAPI software layer  253 . 
     For example, the Microsoft Mail email client program  240  on the personal computer system can send and receive email by issuing requests to the MAPI software layer  253 . The MAPI software layer  253  transmits the requests through the appropriate network software to the MAPI-compliant email server software  281  on a server  280 . The MAPI-compliant email server software responds through the network  270  back to the MAPI layer and thus back to the mail client software  240 . 
     To send and received email, the email conduit  233  uses the same infrastructure. Thus, the email conduit  233  also makes requests to the MAPI software layer  253 . The MAPI software layer  253  transmits the requests from the email conduit  233  through the appropriate network software to the MAPI-compliant email server software  281  on server  280 . 
     It should be noted that the email server software  281  on server  280  maintains the email “state” for each user that the email server services. Specifically, the email server software maintains a set of active email messages for each user. By communicating through the MAPI software layer  253 , the email conduit  233  can synchronize the email records on the portable computer system  210  with the email information on email server software  281  on server  280 . 
     FIG. 3 illustrates a flow diagram that describes how the email client conduit  233  on the personal computer system  250  synchronizes the email state on the portable computer system  210  and the personal computer system  250 . First, at step  310 , the email conduit  233  retrieves all the outgoing email from the portable computer system  210 . This outgoing email is sent to the email server software  281  using MAPI commands such that the outgoing email is sent to the desired recipient. At step  315 , the email conduit determines if the user has selected a “send-only” mode. The send-only mode allows the user to shorten synchronization sessions by only sending outgoing email. If the user has selected the send-only mode the email client is done and stops at step  317 . Otherwise the email conduit continues to synchronize the email in database  215  with the email on the email server software  281 . 
     At step  320 , the email conduit  233  reads all the email for the user from the email server  281 . If the email conduit  233  cannot read the email from the server then the conduit will terminate since it cannot obtain the information necessary for the synchronization. After reading all the email from the email server  281  the email conduit  233  then reads all the email stored in the database  215  in the portable computer system at step  330 . 
     At step  335 , the email conduit  233  checks to see if this is a synchronization with the same personal computer that was used to perform the previous synchronization. If this is the same personal computer, then the email from the portable computer system will have valid status flags that specify the new, changed and deleted email from the portable computer system. However, if this is not the same personal computer that was used in the previous synchronization then the conduit proceeds to step  337  where it compares the email from the portable computer system with the email from the last synchronization to determine the new, changed and deleted email from the portable computer system. Additional information about the system of using a state from a previous synchronization is available in the U.S. patent application entitled “Method and Apparatus for Synchronizing Information on Two Different Computer Systems” with Ser. No. 08/544,927, filed on Oct. 18, 1995, now U.S. Pat. No. 5,727,202. 
     Next, at step  340 , the email from the email server  281  is compared with the email retrieved from the portable to determine the new, changed and deleted email from the email server  281 . After this step the email that is new, changed or deleted from the email server  281  is available. 
     The final step is then to synchronize the email information from the email server  281  and the email information from the portable computer system. To accomplish this goal, the email conduit  233  uses the list of the new, changed and deleted email from the portable computer system and the list of the new, changed and deleted email from the email server  281 . Specifically, the list of the new, changed and deleted email from the portable computer system is used to modify the email on the email server  281  and the list of the new, changed and deleted email from the email server  281  is used to modify the email information on the portable computer system. Thus, at step  350 , if an email message has been deleted from the email server  281  then that email message is deleted from the email list on the portable computer system. Similarly, if an email message has been deleted from the then that email message is deleted from the email server  281  email list on the portable computer system. If an email message has been modified on either system then that email message is modified on the other system. For example, if email has been marked as read on either system then the email is marked as read on the other system. Finally, if new email has been received by the email server  281 , then that new email is copied into the database in the portable computer system. 
     The techniques illustrated with reference to the MAPI based email system of FIG. 2 a  can be used in other email systems. For example, FIG. 2 b  illustrates a similar mail arrangement. In FIG. 2 b , the server  280  is running the Lotus® cc:mail server software  283  on the server  280 . To communicate with the Lotus® cc:mail server software, a VIM software layer  257  is placed in the system software of the personal computer system  250 . The VIM software layer  257  is used by the Lotus® cc:mail client program  242 . Since the VIM and MAPI software layers are very similar, the same method described in FIG. 3 can be used to synchronize email on systems use the VIM protocol. 
     Although the present invention has been described in terms of specific exemplary embodiments, it will be appreciated that various modifications and alterations might be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims.