Database network system

• US 6,484,184 B1
• Filed: 03/08/2000
• Issued: 11/19/2002
• Est. Priority Date: 03/31/1999
• Status: Expired due to Term

• Current Assignee: Enegene Co., Ltd. (Hamanen Co., Ltd.)
• Original Assignee: Hamanen Co., Ltd.
• Inventors: Adachi, Atsushi, Mizushina, Shizuo
• Primary Examiner(s): AMSBURY, WAYNE P
• Application Number:
  US09/522,033
• Time in Patent Office: 986 Days
• Field of Search: 707/104.1
• US Class Current: 1/1
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image

Abstract

A database network system is capable of recognizing in a short time (within several minutes) the state of damage or the like of city lifelines (waterworks, electricity, and gas supplies) over a whole city. A database network system according to the present invention includes a center station, relay database stations (RDSs), and terminal stations. A terminal station group includes a plurality of terminal stations for acquiring changing information to accumulate the information as data and for transmitting the data as requested. Each of the plurality of relay database stations (RDSs) is arranged for the terminal station group, and accumulates pieces of information sequentially received from the terminals as specific data and other data and transmits the data as requested. The center station sequentially receives parts of the specific data and other data of an arbitrary one of the relay database stations (RDSs) from the corresponding relay database station, performs a receiving operation of all the data and the specific information data a plurality of times by performing the receiving operation a plurality of times, and accumulates the data as needed.

Claims

1. A multilayer polling database network system for collecting information, comprising:

a lower polling layer having a plurality of terminal station groups, each group including a plurality (P₂) of terminal stations, each terminal station acquiring information, accumulating the information as data, and transmitting the data during a lower-layer polling period (T₂);

a relay database station layer having a plurality (P₁) of relay database stations, each relay station database communicating with a corresponding terminal station group for acquiring information (b₁) from the terminal stations, extracting specific information (b₂) from the information (b₁) acquired from the terminal stations, dividing the information (b₁) into n (n=1, 2, 3 . . . ) groups and holding the divided information for a predetermined period of time; and

a center station for sequentially polling the relay database stations and acquiring (b₂+b₁/n)×

P₂ bytes of information during an upper-layer polling period (T₁).

2. A database network system according to claim 1, wherein the upper-layer polling period (T₁) and lower-layer polling period (T₂) have the following relations:

3. A database network system according to claim 1, wherein the information is city utility information and the terminal stations are living unit terminals of houses.

4. A database network system according to claim 1, wherein the specific information (b₂) extracted from the information (b₁) is selected based on a degree of emergency.

5. A database network system according to claim 1, wherein the center station comprises a main database which holds the specific information data and the data for a predetermined period of time to provide a history of the operation.

6. A database network system according to claim 1, wherein the information acquired by the terminal station includes at least one of data for reading meter values, data for collecting/monitoring information related to various maintenance jobs, and information data related to security, care of elderly people, water pressures of fire hydrants, and monitors of air-conditioners.

7. A database network system according to claim 1, wherein the plurality of relay database stations includes at least one upper-layer relay database station group and a plurality of lower-layer relay database station groups associated with one of the upper-layer relay database stations,

the database relay stations of the lower-layer relay database station group collect information from the terminal station groups, and

the center station collects information from the upper-layer relay database stations.

8. A method of collecting data, comprising:

collecting data regarding utility networks at a number (P₂) of terminal stations;

arranging the terminal stations into a plurality of groups;

associating each group of terminal stations with at least one of a number (P₁) of relay database stations;

transmitting the data (b₁) from the groups of terminal stations to the associated relay database station during to a second polling period (T2);

extracting selected information (b₂) from the transmitted data (b₁) at the relay database stations;

dividing the data (b₁) into n (n=1, 2, 3 . . . ) groups; and

sequentially polling the relay database stations with a center station to acquire (b1+b2/n)*P₂ bytes of information during a first polling period (T1).

9. The method of claim 8, further comprising holding the data b₁ at the relay database stations for a predetermined period of time.

10. The method of claim 8, wherein the first polling period (T₁) and the second polling period (T₂) have following relations: