Sensor network system and data transfer method for sensing data

• US 7,860,917 B2
• Filed: 01/20/2006
• Issued: 12/28/2010
• Est. Priority Date: 03/24/2005
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Moriwaki, Norihiko
• Primary Examiner(s): Patel; Ashok B
• Assistant Examiner(s): GOLDBERG, ANDREW C
• Application Number:
  US11/335,633
• Publication Number:
  US 20060242285A1
• Time in Patent Office: 1,803 Days
• Field of Search: 709/223
• US Class Current: 709/201
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

To suppress a server processing load and a network load in a sensor network which accommodates a great number of mobile sensor nodes. Among a plurality of distributed data processing servers (DDS) for managing data of sensor nodes, a distributed data processing server (DDS) that is a home server to hold data of a mobile sensor node is set for each sensor node by a directory server (DRS). At each distributed data processing server (DDS), upon reception of the data from the sensor node, identification process is executed as to whether the data is sensor data to be managed by itself or another distributed data processing server. If a result of the identification is the sensor data to be managed by another distributed data processing server, the data is transferred to the distributed data processing server (DDS-1), which corresponds to the home server of the sensor data, based on setting of the directory server (DRS).

Claims

1. A sensor network system comprising:

a plurality of mobile sensor nodes, each of which includes a sensor which obtains data from users of said sensor network, and a transmission unit which transmits the data including an identifier for identifying the data from an associated sensor node;

a first base station and a second base station each of which receives the data;

a first distributed processing server connected to said first base station and a second distributed processing server connected to said second base station, each of which includes

a reception unit which receives the data transmitted from said sensor node through said base stations;

an extractor which extracts said identifier from the received data;

a memory which records a list which holds said identifier and the data corresponding to said identifier;

a judging module which judges whether or not said extracted identifier is held in said list;

an executer which stores said data in said memory based on the judgment results of said judging module;

a management server which comprises a system manager which manages said identifier of each of said sensor nodes and an associated said first distributed processing server for holding the data associated with said identifier, wherein;

when said first distributed processing server receives the data transmitted from said mobile sensor node, the executer of said first distributed processing server holds the data as a preset process,

when said mobile sensor node moves from said first base station to said second base station and said second distributed processing server receives the data transmitted from said mobile sensor node,

if said extracted identifier is held in said list, said executer of said second distributed processing server transfers the data to said first distributed processing server as said preset process, and

if said extracted identifier is not held in said list, said second distributed processing server makes an inquiry to said management server, said management server transmits the location of said first distributed processing server, and said second distributed processing server holds said extracted identifier and the location of said first distributed processing server in said list and transfers the data to said first distributed processing server.

2. The sensor network system according to claim 1, wherein:

said second distributed processing server transfers the data to the management server when the list does not hold the identifier.

3. The sensor network system according to claim 2, wherein said management server further comprises an action table which holds an identifier managed by said system manager and the location of said first distributed processing server for holding data including the identifier in association with each other, and transfers the data to said first distributed processing server based on said action table when the data is transferred from said second distributed processing server.

4. A sensor network system according to claim 3, wherein in a case where said identifier included in the data is not held in said action table when the data is transferred from said second distributed processing server, said management server instructs said action table to holds said identifier managed by said system manager and the location of said first distributed processing server for holding the data including said identifier based on a transferred identifier.

5. The sensor network system according to claim 1, wherein said second distributed processing server sets discarding of the received data including said identifier if the received identifier is not managed by said system manager.

6. The sensor network system according to claim 1, wherein said second distributed processing server holds in said list the identifier and the location of said first distributed processing server for holding the data including said identifier based on the inquiry to the management server, and deletes said identifier and the location of said first distributed processing server for holding the data including said identifier from said list when the data is not received from said sensor node for a predetermined time.

7. The sensor network system according to claim 1, wherein one of said first distributed processing server and said second distributed processing server receives the data including position information indicating a position of said sensor node.

8. The sensor network system according to claim 7,

wherein each of said first base stations and the second base station adds one of an identifier or an address of the base station itself as the position information to the data received from said sensor node.

9. The sensor network system according to claim 7,

wherein each of said first base station and said second base station adds one of an identifier and an address of the base station itself as the position information to the data received from said sensor node.

10. The sensor network system according to claim 8, wherein:

said management server transmits a command to be sent to said sensor node to said first distributed processing server;

and said first distributed processing server transmits said command to the base station which receives the data transmitted from said sensor node based on the received position information indicating the position of said sensor node.

11. A control system embodying a program for causing a distributed processing server to receive data from a sensor node and to perform one of transferring the data or holding the data, said data including an identifier for identifying the data, wherein said program causes the distributed processing server to execute:

a process of receiving the data from said sensor node;

a process of judging a holding place of the data;

a process of transferring the data when the holding place is another distributed processing server;

a process of receiving data from a management server and another distributed processing server; and

a process of holding data when the data is received from the management server and another distributed processing server, when the holding place of the data is the distributed processing server; and

a memory for holding a list of identifiers extracted from the received data and storing said received data corresponding to said identifiers,

wherein;

when a first distributed processing server receives the data transmitted from said mobile sensor node, the executer of said first distributed processing server holds the data,

when said sensor node moves from a first base station to a second base station and a second distributed processing server receives the data transmitted from said sensor node,

if the extracted identifier is held in said list, said executer of said second distributed processing server transfers the data to said first distributed processing server for holding,

if the extracted identifier is not held in said list, said second distributed processing server makes an inquiry to said management server, said management server transmits the location of said first distributed processing server, and said second distributed processing server holds the extracted identifier and the location of said first distributed processing server in said list and transfers the data to said first distributed processing server.

12. The control system according to claim 11, wherein:

said process of judging the holding place of the data includes a process of making an inquiry about the holding place of the received data to the management server, and a process of judging whether the inquired holding place is another distributed processing server or the distributed processing server; and

said process of transferring the data transfers the received data to the management server.

13. The control system according to claim 11, wherein:

said process of judging the holding place of the data includes a process of making an inquiry about the holding place of the received data to the management server, and a process of judging whether the inquired holding place is another distributed processing server or the distributed processing server; and

said process of transferring the data transfers the received data to another distributed processing server based on a result of the inquiry.

14. The control system according to claim 12, wherein:

said process of receiving the data from the sensor node includes a process of extracting a data identifier from the received data;

said process of making the inquiry to the holding place makes an inquiry about the holding place of the received data to the management server based on the identifier;

said process of judging the holding place of the data includes a process of holding the identifier and a preset process corresponding to the identifier in a list; and

said process of judging the holding place judges that the holding place is the distributed processing server if the identifier is in the list, and that the holding place is another distributed processing server if the identifier is not in the list.

15. The control system according to claim 13, wherein:

said process of receiving the data from the sensor node includes a process of extracting a data identifier from the received data;

said process of judging the holding place of the data includes a process of holding the identifier and a preset process corresponding to the identifier in a list, and judgment is made as to whether the holding place of the data is the distributed processing server or another distributed processing server from the list based on the identifier; and

said process of transferring the data transfers the data including the identifier to another distributed processing server corresponding to the identifier.

16. The control system according to claim 13, wherein:

said process of receiving the data from the sensor node includes a process of extracting a data identifier from the received data;

said process of making the inquiry to the holding place makes an inquiry about the holding place of the received data to the management server based on the identifier;

said process of judging the holding place of the data includes a process of holding the identifier and a holding place corresponding to the identifier in a list, and judgment is made as to whether the holding place of the data is the distributed processing server or another distributed processing server by obtaining a holding place of data from the list based on the identifier; and

the process of transferring the data transfers the data including the identifier to another distributed processing server of the holding place.

17. The control system according to claim 16, wherein when the holding place of the data is not obtained from said list based on the identifier, said process of judging the holding place of the data discards the received data.

18. The control system according to claim 16, further comprising a process of deleting the identifier and the holding place from said list when the data including the identifier indicating that the holding place is another distributed processing server is not received for over a predetermined time period.

19. The control system according to claim 11, wherein said process of receiving the data from the sensor node receives the data including position information of the sensor node.

20. The control system according to claim 19, wherein said process of receiving the data from said sensor node receives data including an identifier or an address of a base station which relays the data of said sensor node, and

said process of transferring the data transfers the data including a data identifier and one of the identifier and the address of the base station.

21. The control system according to claim 20, wherein:

said process of receiving the data from the management server and another distributed processing server receives a command including position information of the base station from the management server; and

said process of transferring the data transfers data including the command to the base station corresponding to the identifier.

22. A control system embodying a program for causing a management server to receive data from a distributed processing server and to transfer the data to another distributed processing server, wherein said program causing said management server to execute:

a process of receiving data from the distributed processing server;

a process of retrieving a holding place of the data; and

a process of transferring the data to the holding place;

a memory for holding a list of identifiers extracted from the received data and a preset process corresponding to said identifiers,

wherein;

when a first distributed processing server receives the transmitted data, the executer of said first distributed processing server holds the data,

when said sensor node moves from a first base station to a second base station and a second distributed processing server receives the data transmitted from said sensor node,

if the extracted identifier is held in said list, said executer of said second distributed processing server transfers the data to said first distributed process server for holding,

if the extracted identifier is not held in said list, said second distributed processing server makes an inquiry to said management server, said management server transmits the location of said first distributed processing server, and said second distributed processing server holds the extracted identifier and the location of said first distributed processing server in said list and transfers the data to said first distributed processing server.

23. The control system according to claim 22, wherein:

said process of judging searches in an action table including the identifier and a preset holding place corresponding to the identifier to judge a holding place of the data; and

said process of transferring the data transfers the data to the holding place retrieved from the action table.

24. The control system according to claim 23, wherein said process of judging obtains the holding place corresponding to said identifier from a preset sensor node information table when said identifier is not in the action table, and holds said identifier and the holding place corresponding to said identifier in said action table.

25. The control system according to claim 24, wherein said process of judging discards the received data when the holding place corresponding to said identifier is not in said sensor node information table.