Data synchronization system, data synchronization method, data center, and client terminal

• US 20030055996A1
• Filed: 01/22/2002
• Published: 03/20/2003
• Est. Priority Date: 09/18/2001
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Mori, Shinichiro, Ogawa, Ai
• Granted Patent: US 7,085,809 B2
• Time in Patent Office: Days
• US Class Current: 709/232
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/55 Push-based network services
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04W 4/00 Services specially adapted for wireless communication networks; Facilities therefor

Abstract

There is provided a data synchronization system, data synchronization method, data center, and client terminal that allow a client terminal to determine whether data held by the client terminal is up-to-date and allow synchronization between a server and the client to be maintained at low costs in a case where synchronization between data in the server and data in the client terminal is provided.

The data synchronization system for keeping the sameness between data in a client terminal 10 and data in a data server 20 through a communication link comprises a synchronization data transmitter 25 for sending to the client terminal 10 data to be kept same as data in the client terminal 10, a synchronization signal output module 33 for sending a synchronization signal for checking the sameness to the client terminal 10 at predetermined timing, and a synchronization signal transmission controller 23 for controlling the transmission of the synchronization signal by the synchronization signal output module 33 based on the result of the synchronization signal transmission by the synchronization signal output module 33.

Claims

1. A data center for keeping the sameness between data in client terminal and data in a server through a communication link, said data center comprising:

a server for storing data to be kept same as data in said client terminal;

data transmission means for sending data to be kept same as the data in said client terminal to said client terminal;

signal transmission means for sending a signal for checking the sameness at predetermined timing to said client terminal; and

control means for controlling the signal transmission performed by said signal transmission means based on the result of the transmission by said data transmission means.

2. The data center according to claim 1. wherein said client terminal is a portable information terminal and said communication link is a radio link.

3. The data center according to claim 1, wherein said control means stops the signal transmission by said signal transmission means if the transmission by said data transmission means results in an error.

4. The data center according to claim 3, wherein said control means causes the signal transmission by said signal transmission means to be resumed if the data transmission performed by said data transmission means after the signal transmission by said signal transmission means is stopped succeed.

5. The data center according to claim 1, wherein the sender telephone number of said data transmission means and the sender telephone number of said signal transmission means are different from each other so that, when an incoming receipt occurs at said client terminal, it can be determined whether the receipt is the receipt of data sent from said data transmission means or the receipt of a signal sent from said signal transmission means.

6. The data center according to claim 1, wherein a transmission frequency used by said signal transmission means and a transmission frequency used by said data transmission means are different from each other so that, when receipt occurs at said client terminal, it can be determined whether the receipt is the receipt of data sent from said data transmission means or the receipt of a signal sent from said signal transmission means.

7. The data center according to claim 1, wherein the signal sent by said signal transmission means is sent as a sound wave so that, when receipt occurs at said client terminal, it can be determined whether the receipt is the receipt of data sent from said data transmission means or the receipt of a signal sent from said signal transmission means.

8. The data center according to claim 1, wherein the signal sent by said signal transmission means is sent as infrared so that, when receipt occurs at said client terminal, it can be determined whether the receipt is the receipt of data sent from said data transmission means or the receipt of a signal sent from said signal transmission means.

9. The data center according to claim 1, wherein, when said data transmission means received a send request from said client terminal, said data transmission means sends data to said client terminal based on said send request.

10. The data center according to claim 1, further comprising timing setting means for setting said predetermined timing.

11. A data synchronization system for keeping the sameness between data in client terminal and data in a server through a communication link, said system comprising:

signal transmission means for sending a signal for checking the sameness to said server at predetermined timing;

transmission result detection means for detecting the result of transmission performed by said signal transmission means; and

control means for controlling said client terminal based on the transmission result detected by said transmission result detection means.

12. A client terminal for keeping the sameness between data in said client terminal and a server through a communication link, said client terminal comprising:

receiving means for receiving data to be kept same as data in said server and a signal for checking the sameness, said data being sent to said client terminal when needed and said signal being sent at predetermined timing;

receiving status detecting means for detecting the receiving status of said signal for checking the sameness sent at said predetermined timing; and

processing means for performing a predetermined process based on the receiving status detected by said receiving status detecting means.

13. The client terminal according to claim 12, further comprising;

receipt type determination means for determining the type of receipt;

connection control means for controlling connection and disconnection of a line for said receipt according to the result of the determination by said receipt type determination means.

14. The client terminal according to claim 13, wherein said connection control means disconnect the line for said receipt if said receipt type determination means determines that said receipt type is the receipt of a signal sent by said signal transmission means.

15. The client terminal according to claim 12, further comprising;

sameness status determination means for determining the sameness status of the current data based on received signal strength and whether said signal is received or not; and

display means for displaying the determination result of said sameness status determination means.

16. The client terminal according to claim 15, wherein said sameness status determination means determines that the sameness between data in said client terminal and data in said server is not kept if it is determined based on said received signal strength that said client terminal is within an area where the signal reaches and said signal is not received at said predetermined timing.

17. The client terminal according to claim 15, further comprising transmission request means for requesting for the transmission of data to be kept same as data in said server from said server if said sameness status determination means determines that the data is not kept same as the data in said server.

18. The client terminal according to claim 12, wherein a line for said received signal is disconnected if said receiving status detecting means detects that the receiving status of said signal is normal.

19. A data synchronization system for keeping the sameness between data in client terminal and data in a server through a communication link, said system comprising:

a server for storing data to be kept same as data in said client terminal;

data transmission means for sending data to be kept same as the data in said client terminal to said client terminal;

signal transmission means for sending a signal for checking the sameness at predetermined timing to said client terminal;

control means for controlling the signal transmission performed by said signal transmission means based on the result of the transmission of the data by said data transmission means; and

a client terminal for receiving data sent from said data transmission means and a signal sent from said signal transmission means.

20. The data synchronization system according to claim 19, wherein said client terminal comprises timing setting meaning for setting said predetermined timing.

21. A data synchronization method for sending a signal for checking the sameness of data to a client terminal at predetermined timing;

sending data to said client terminal as required, the sameness of said data being to be kept between said client terminal and a predetermined server, detecting a situation where said sent data is not received by said client terminal, and, if said situation where said sent data is not received by said client terminal is detected, stopping the transmission of said signal.

22. The data synchronization method according to claim 21, wherein said client terminal requests for the transmission of said data to be kept same as data in said server if said client terminal cannot receive said signal.

23. The data synchronization method according to claim 21, wherein, if it is detected that said client terminal receives data to be kept same as the data in said server after the transmission of said signal is stopped, the transmission of said signal is resumed.

24. The data synchronization method according to claim 21, wherein, if receipt occurs in said client terminal, said client terminal determines the type of said receipt, and if it determined that said receipt is the receipt of said signal for checking said sameness, disconnects the line for said receipt.