Abstract:
A gateway system comprises a character code conversion table, a data code conversion table, a data format conversion table, and a transmitter/receiver combination table. Concerning data exchange among a plurality of information systems, which are connected in the same network as that connected to this gateway system, the gateway system has a function of checking whether or not combination of a transmitter and a receiver is appropriate by referring to the transmitter/receiver combination table, and a function of performing data format conversion, data code conversion, and character code conversion corresponding to the combination of the transmitter and the receiver by referring to the related tables. In addition, each of the information system is connected to the gateway system via the network, and has a transmitter/receiver combination table and a function of checking validity of transmitter/receiver combination included in received data by referring to this table.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a gateway system characterized in that said gateway system provides a communication protocol conversion function and a data format conversion function which are used at the time of connection to another system connected to an open network typified by Internet, and that said gateway system itself is also connected to the open network. 
   A method that is conventionally and usually used to settle differences of communication protocols, data formats, etc. between systems is the following: the data formats and the communication protocols are converted using various kinds of conversion programs. For example, communication over two networks can be realized by installing a machine, which executes a program for converting a protocol on the machine, in each of the networks to perform data communication between networks that adopt a different communication protocol each other. 
   However, the program and the system for realizing the communication are made by each company individually for its own use. In addition, hardware, on which the gateway system operates, is also prepared by each company on its own account. Therefore, initial investment for development and operation cost were required. Moreover, because of difference between communication protocols or between data formats, it is usually required to build a gateway system separately for each destination, resulting in an increase in a cost and in a burden on humans. Therefore, if a number of destinations is many, a huge cost is required to cover all of the destinations. 
   By the way, as a result of a recent Internet boom, Internet exchanges, at which commodities are dealt with on Internet, become widespread. In addition to it, as regards purchase behavior of an individual, dependency on Internet is also increased. Therefore, each company encounters a situation in which the company is forced to handle business transactions on Internet. Under the circumstance, an information system is required to be connected to an open network such as Internet. However, because the conventional information system is not developed on the assumption that the information system is connected to an open network, it is necessary to modify the system profoundly, or to update the system, in order to achieve the connection. This requires a great expense. However, because of a considerable change in recent management environment, it is not easy to subsidize the expense. 
   SUMMARY OF THE INVENTION 
   On the other hand, recently, as a company that leases business application software to a customer through an open network typified by Internet, an application service provider (hereinafter it is abbreviated as ASP) is gaining attention. In this case, a user uses a Web browser to utilize application software installed in a server possessed by ASP. If such an application is utilized, it is not necessary to install an individual application on a user&#39;s personal computer. Because of it, reduction of cost and time required for installation, management, and upgrade, which were a considerable burden on the information system department of the company, becomes possible. 
   In order to achieve the above-mentioned object, the present invention provides a user with the following gateway system in a form of the above-mentioned ASP: in a gateway system that performs data format conversion, etc. at the time of data transmission between two information systems, which are connected through a network, the gateway system can handle a portion, which should be customized for each user, only by changing various tables without changing a kernel portion. In addition, as regards an interface to the information system through the gateway, providing the user with the interface in the form of ASP enables a destination company, which does not have their own information system, to reduce expenditure on clerical work. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a configuration diagram illustrating a whole gateway system in an embodiment of the present invention; 
       FIG. 2  is a flowchart illustrating a process flow in a gateway site; 
       FIG. 3  is a flowchart illustrating a process flow of data transmission in an interface site; 
       FIG. 4  is a flowchart illustrating a process flow of data reception in an interface site; 
       FIG. 5  is a flowchart illustrating a process flow at the time of data transmission in a customer site; and 
       FIG. 6  is a flowchart illustrating a process flow at the time of data reception in a customer site. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of the present invention will be described in detail with reference to drawings as below. 
     FIG. 1  illustrates a network system that constitutes the present invention. A gateway site  10  comprises the following: a control unit  110  for controlling a whole system; a character code conversion table  120  that holds information for converting two or more kinds of character codes; a data format conversion table  140  that holds information for converting data format; a data code conversion table  130  that holds information on differences of various data codes among systems; a transmitter/receiver combination table  150  having information on judgment as to whether combination of a transmitter and a receiver is appropriate; and an encryption/decryption table  160  having information on encryption of data to be transmitted and decryption of received data. The gateway site  10  is connected to a customer site  30  via a network  50 . Examples of the network  50  include an open network typified by Internet, and various kinds of dedicated lines. In this case, information before conversion and after conversion, information on a decryption key corresponding to an encryption key, or the like, is preset in the character code conversion table  120 , the data code conversion table  130 , the data format conversion table  140 , the transmitter/receiver combination table  150 , and the encryption/decryption table  160 , corresponding to combination of a transmitter identifier and a receiver identifier. The settings permit ASP of one-to-one communication gateway between the transmitter and the receiver to be realized. 
   The customer site  30  comprises the following: a communication control unit  310  for controlling communication with the gateway site  10 ; an encryption/decryption table  320  having information on encryption of data to be transmitted and decryption of received data; a transmitter/receiver combination table  330  having information on judgment as to whether or not combination of a transmitter and a receiver is appropriate; and a customer information system  340  that includes various kinds of systems required to carry out customer&#39;s business. Examples of the customer information system  340  include an ordering system, an inventory management system, and various kinds of reservation systems. 
   In addition, the gateway site  10  is connected to an interface site  20  having a user interface function that performs various kinds of data processing for a information system connected to the gateway system through a network  60 . Examples of the network  60  include an open network typified by Internet, various kinds of dedicated lines, and a local area network. 
   The gateway site  10  is connected to a customer site  40 , which is separate from the customer site  30 , via a network  70  as necessary. Examples of the network  70  include an open network typified by Internet, and various kinds of dedicated lines. The customer site  40  comprises the following: a communication control unit  410  for controlling communication with the gateway site  10 ; an encryption/decryption table  420  having information on decryption of received data; a transmitter/receiver combination table  430  having information on judgment as to whether or not combination of a transmitter and a receiver is appropriate; and a customer information system  440  that includes various kinds of systems required to carry out customer&#39;s business. As an example of the customer information system  440 , there is a system such as an ordering system and supply chain management system, which can operate in conjunction with the customer site  30 . 
   On the other hand, the interface site  20  can be connected to the customer site  40  via the network  80 . In this case, an open network typified by Internet, or various kinds of dedicated lines can be used as the network  80 . The interface site  20  comprises the following: a control unit  210  for controlling an entire system; a transmitter/receiver combination table  220  having information on judgment as to whether or not combination of a transmitter and a receiver is appropriate; and an encryption/decryption table  230  having information on encryption of data to be transmitted. The interface site  20  provides a user interface for accessing the customer site  30  via the gateway site  10 . 
   If the customer site  40  does not have an interface such as a graphical interface, which is used to access the customer site  30  via the gateway site  10 , the control unit  210  in the interface site  20  performs interface processing as shown in  FIG. 3 . The interface site  20  plays a role as ASP that has an interface function. 
     FIG. 2  is a flowchart illustrating processing performed in the gateway site  10  at the time of communication between the customer site  30  and the customer site  40 , or communication between the customer site  30  and the interface site  20 . To simplify explanation, a case where data is transmitted from the customer site  30  to the customer site  40  will be described as an example. When the gateway site  10  receives the data from the customer site  30 , a communication protocol is converted from a form peculiar to the customer site  30  to a form peculiar to the gateway site (step  500 ). The gateway site  10  collates information on transmitter/receiver combination, and checks whether or not combination of a transmitter identifier and a receiver identifier, which are added to the data, is valid (step  502 ). After the validity is confirmed, in the next place, the gateway site  10  decrypts the data with reference to the encryption/decryption table  160  (step  504 ). In addition, the gateway site  10  converts character codes with reference to the character code conversion table  120  (step  506 ). Then, the gateway site  10  converts data codes with reference to the data code conversion table  130  (step  508 ). After that, the gateway site  10  converts a data format with reference to the data format conversion table  140  (step  510 ). The gateway site  10  encrypts the data, of which data format has been converted, with reference to the encryption/decryption table  160  (step  512 ). The gateway site  10  adds the transmitter identifier and the receiver identifier to the encrypted data with reference to the information on transmitter/receiver combination  150  (step  514 ). Finally, the gateway site  10  converts the communication protocol into that adopted by the customer site  40 , and transmits the data to the customer site  40  before the processing ends (step  516 ). 
   The above-mentioned processing can be achieved by a program in the gateway site. Moreover, such a program can be stored in a computer-readable storage medium such as CD-ROM. 
     FIG. 3  is a flowchart illustrating a process flow in which a user logs in the interface site  20  and data is transmitted. Once the user in the customer site  40  logs in, the login is accepted in the interface site  20  (step  600 ). The interface site  20  authenticates the user, who has logged in, with the use of the authentication database (step  602 ). When the user is authenticated, menu information is transmitted from the interface site  20  to the terminal of the user in the customer site  40  (step  604 ). The user selects a sub menu, which the user wants to use, from a displayed menu (step  606 ). When the interface site  20  receives information on a sub menu number, the interface site  20  performs processing of the selected menu (step  608 ). As a result of the menu processing, if data exchange with the customer site  30  or the gateway site  10  is required, the encryption/decryption table  220  is referred to before the transmission data is encrypted (step  610 ). Then, with reference to the transmitter/receiver combination table  220 , a transmitter identifier and a receiver identifier are added to the data to be transmitted (step  612 ). Finally, the data is transmitted from the interface site  20  to the gateway site  10 , and then the processing ends (step  614 ). 
     FIG. 4  is a flowchart illustrating a process flow in which the interface site  20  receives data from the gateway site  10  and displays the data for a user. When data is transmitted from the gateway site  10 , the data is received (step  700 ). With reference to the transmitter/receiver combination table  20 , whether or not combination of a transmitter and a receiver is valid is checked (step  702 ). If a result of the verification is appropriate, the encryption/decryption table  230  is referred to, and then the data is decrypted (step  704 ). Finally, the decrypted data is displayed in the terminal of the user who is accessing the interface site (step  706 ). 
     FIG. 5  is a flowchart illustrating a process flow of data transmission in the customer site  30  (the process flow is the same as that of the customer site  40 ). When data to be transmitted from a system in the customer site  30  to a system in the customer site  40  is generated, the encryption/decryption table  320  in the customer site  30  is referred to before the data is encrypted (step  800 ). Then, with reference to the transmitter/receiver combination table  330 , a transmitter identifier and a receiver identifier are added (step  802 ). Finally, the data is transmitted to the gateway site  10  (step  804 ). 
     FIG. 6  is a flowchart illustrating a process flow of data reception in the customer site  30  (the process flow is the same as that of the customer site  40 ). When the customer site  30  receives data that has been transmitted from the gateway site  10  (step  900 ), the customer site  30  refers to the transmitter/receiver combination table  330 , and check whether or not combination of a transmitter identifier and a receiver identifier, which have been added to the transmitted data, is valid (step  902 ). If a result of the verification is appropriate, the encryption/decryption table  320  is referred to, and then the data is decrypted (step  904 ). Finally, the decrypted data is transmitted to the customer information system  340 , which requires the data and then the processing ends (step  906 ). 
   The processing illustrated by the flowchart in the drawing described above can be realized by programs in the interface site  20 , the customer site  30  and the customer site  40 . Moreover, such a program can be stored in a computer-readable storage medium such as CD-ROM. 
   According to the present invention, it is possible to realize cooperation between an own organization&#39;s information system and an external information system without bearing a heavy burden of system development and operation. Moreover, it is also possible to handle business transactions easily through an open network such as Internet.