Distributed network computing system for data exchange/conversion between terminals

Abstract

A data exchange unit is arranged in a server. Service data provided as an application service is converted into a predetermined format on the basis of the attribute data of a terminal as a communication partner and is transmitted. With this processing, the application service can be provided while adjusting the relative difference in processing capability terminals. When the service data is converted into a predetermined format on the basis of the attribute of a communication network connected to the terminal and transmitted, the application service can be provided while adjusting the relative difference in communication capability among communication networks. Also, terminal equipment 51 is able to communicate with server computer while keeping the security function.

Claims

What is claimed is:

1. A distributed network computing system comprising:

a data processing unit for providing an application service of various application software;

a terminal for receiving the application service from said data processing unit;

a communication network which connects said data processing unit and said terminal;

a network connecting means for connecting networks each other; and

a data exchange unit provided at the network connecting means;

said data exchange unit further comprising:

a terminal attribute data management means for managing terminal attribute data representing a processing capability of said terminal;

a conversion means for acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management means and converting service data provided as the application service into a specific format on the basis of the terminal attribute data;

a communication means for transmitting through said communication network the service data converted by said communication means, and

a controlling means for enabling the terminal equipment to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

2. A distributed network computing system comprising:

a data processing unit for providing an application service of various application software;

a terminal for receiving the application service from said data processing unit;

a communication network which connects said data processing unit and said terminal,

a network connecting means for connecting networks each other and

a data exchange unit provided at the network connecting means;

said data exchange unit further comprising:

a communication infrastructure data management means for managing communication infrastructure data representing a communication capability of said communication network;

a conversion means for acquiring the communication infrastructure data of said communication network connected to said terminal as a communication partner from said communication infrastructure data management means and converting service data provided as the application service into a specific format on the basis of the communication infrastructure data, and

a communication means for transmitting through said communication network the service data converted by said communication means, and

a controlling means for enabling the terminal equipment to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

3. A distributed network computing system comprising:

a data processing unit for providing an application service of various application software;

a terminal for receiving the application service from said data processing unit;

a communication network which connects said data processing unit and said terminal;

a network connecting means for connecting networks each other and

a data exchange unit provided at the network connecting means;

said data exchange unit further comprising:

a terminal attribute data management means for managing terminal attribute data representing a processing capability of said terminal;

a communication infrastructure data management means for managing communication infrastructure data representing a communication capability of said communication network;

a conversion means for acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management means and the communication infrastructure data of said communication network connected to said terminal from said communication infrastructure data management means, and for converting service data provided as the application service into a specific format on the basis of the terminal attribute data and the communication infrastructure data;

a communication means for transmitting through said communication network the service data converted by said communication means, and

a controlling means for enabling the terminal equipment to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

4. A distributed network computing system comprising:

a first data processing unit for providing an application service of various application software;

a terminal for receiving the application service from said first data processing unit;

a communication network which connects said first data processing unit and said terminal, and

a second data processing unit connected to said communication network independently of said first data processing unit and having terminal attribute data management means for managing terminal attribute data representing a processing capability of said terminal,

wherein said first data processing unit further comprises:

retrieval means for retrieving said second data processing unit having said terminal attribute data management means;

conversion means for acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management means and converting service data provided as the application service into a specific format on the basis of the terminal attribute data in said second data processing unit retrieved by said retrieval means;

a communication means for transmitting through said communication network the service data converted by said conversion means, and

a controlling means for enabling the terminal equipment to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

5. A distributed network computing system comprising:

a first data processing unit for providing an application service of various application software;

a terminal for receiving the application service from said first data processing unit;

a communication network which connects said first data processing unit and said terminal, and

a second data processing unit connected to said communication network independently of said first data processing unit and having communication infrastructure data management means for managing communication infrastructure data representing a communication capability of said communication network,

wherein said first data processing unit further comprises:

a retrieval means for retrieving said second data processing unit having said communication infrastructure data management means;

a conversion means for acquiring the communication infrastructure data corresponding to said terminal as a communication partner from said communication infrastructure data management means and converting service data provided as the application service into a specific format on the basis of the communication infrastructure data in said second data processing unit retrieved by said retrieval means;

a communication means for transmitting through said communication network the service data converted by said conversion means, and

a controlling means for enabling the terminal equipment to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

6. A distributed network computing system comprising:

a first data processing unit for providing an application service of various application software;

a terminal for receiving the application service from said first data processing unit;

a communication network which connects said first data processing unit and said terminal, and

a second data processing unit connected to said communication network independently of said first data processing unit and having terminal attribute data management means for managing terminal attribute data representing a processing capability of said terminal and communication infrastructure data management means for managing communication infrastructure data representing a communication capability of said communication network,

wherein said first data processing unit comprises:

a retrieval means for retrieving said second data processing unit having said terminal attribute data management means and said communication infrastructure data management means;

a conversion means for acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management means and simultaneously acquiring the communication infrastructure data corresponding to said terminal as the communication partner from said communication infrastructure data management means, and converting service data provided as the application service into a specific format on the basis of the terminal attribute data and the communication infrastructure data in said second data processing unit retrieved by said retrieval means;

a communication means for transmitting through said communication network the service data converted by said conversion means, and

a controlling means for enabling the terminal equipment to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

7. A system according to any one of claims 1, 2, 3, 4, 5 and 6, wherein said terminal comprises a plurality of terminals present on a network.

8. A system according to any one of claims 1, 2, 3, 4, 5 and 6, wherein said communication network comprises a plurality of communication networks present on a network.

9. A system according to any one of claims 1, 2, 3, 4, 5 and 6, wherein said terminal and said communication network respectively comprise a plurality of terminals and a plurality of communication networks present on a network.

10. A system according to any one of claims 1, 2, 3, 4, 5 and 6, wherein said terminal also functions as a server computer.

11. A system according to any one of claims 1, 2, and 3, wherein said network connection means comprises a plurality of network connection means present on said network, and functions of said data exchange unit are distributed to said plurality of network connection means.

12. A system according to any one of claims 1, 2, and 3, wherein said network connection means is integrally arranged in said data processing unit to constitute an integrated server together with said data processing unit.

13. A system according to any one of claims 1, 2, and 3, wherein said data exchange unit is arranged on said network independently of said data processing unit and said network connection means.

14. A system according to any one of claims 1, 2, and 3, wherein said data exchange unit comprises user interface data management means for managing user interface data representing an operation method unique to each terminal, and

said conversion means obtains user interface data corresponding to said terminal as the communication partner from said user interface data management means and converts the service data provided as the application service into a specific format on the basis of the user interface data.

15. A system according to any one of claims 1, 2, and 3, wherein said data exchange unit comprises user data management means for managing user data representing an operation method unique to each user, and

said conversion means obtains user data corresponding to said terminal as the communication partner from said user data management means and converts the service data provided as the application service into a specific format on the basis of the user data.

16. A system according to claim 1, wherein said data exchange unit comprises

enciphering determination means for determining on the basis of the terminal attribute data whether data enciphering is enabled, and

enciphering means for enciphering the service data provided as the application service when said enciphering determination means determines that data enciphering is enabled.

17. A system according to any one of claims 4, 5, and 6, wherein said second data processing unit comprises user interface data management means for managing user interface data representing an operation method unique to each terminal,

said retrieval means retrieves said second data processing unit having said user interface data management means, and

said conversion means obtains user interface data corresponding to said terminal as the communication partner from said user interface data management means and converts the service data provided as the application service into a specific format on the basis of the user interface data in said second data processing unit retrieved by said retrieval means.

18. A system according to any one of claims 4, 5, and 6, wherein said second data processing unit comprises user data management means for managing user data representing an operation method unique to each user,

said retrieval means retrieves said second data processing unit having said user data management means, and

said conversion means obtains user data corresponding to said terminal as the communication partner from said user data management means and converts the service data provided as the application service into a specific format on the basis of the user data in said second data processing unit retrieved by said retrieval means.

19. A system according to claim 4, wherein said second data processing unit comprises:

enciphering determination means for determining on the basis of the terminal attribute data whether data enciphering is enabled, and

enciphering means for enciphering the service data provided as the application service when said enciphering determination means determines that data enciphering is enabled.

20. A system according to claim 16 or 19, wherein said enciphering means changes an enciphering level in correspondence with the processing capability of said terminal.

21. A system according to claim 2, wherein said data exchange unit comprises:

enciphering determination means for determining on the basis of the communication infrastructure data whether data enciphering is enabled, and

enciphering means for enciphering the service data provided as the application service when said enciphering determination means determines that data enciphering is enabled.

22. A system according to claim 5, wherein said second data processing unit comprises:

enciphering determination means for determining on the basis of the communication infrastructure data whether data enciphering is enabled, and

enciphering means for enciphering the service data provided as the application service when said enciphering determination means determines that data enciphering is enabled.

23. A system according to claim 22, wherein said enciphering means changes an enciphering level in correspondence with the communication capability of said communication network.

24. A system according to claim 3, wherein said data exchange unit comprises:

enciphering determination means for determining on the basis of the terminal attribute data and the communication infrastructure data whether data enciphering is enabled, and

enciphering means for enciphering the service data provided as the application service when said enciphering determination means determines that data enciphering is enabled.

25. A system according to claim 4, wherein said second data processing unit comprises:

enciphering determination means for determining on the basis of the terminal attribute data and the communication infrastructure data whether data enciphering is enabled, and

enciphering means for enciphering the service data provided as the application service when said enciphering determination means determines that data enciphering is enabled.

26. A system according to claim 24 or 25, wherein said enciphering means changes an enciphering level in correspondence with the processing capability of said terminal and the communication capability of said communication network.

27. A system according to claim 1, wherein said data exchange unit comprises:

compression determination means for determining on the basis of the terminal attribute data whether data compression is enabled, and

compression means for compressing the service data provided as the application service when said compression determination means determines that data compression is enabled.

28. A system according to claim 4, wherein said second data processing unit comprises:

compression determination means for determining on the basis of the terminal attribute data whether data compression is enabled, and

compression means for compressing the service data provided as the application service when said compression determination means determines that data compression is enabled.

29. A system according to claim 27 or 28, wherein said compression means changes a compression level in correspondence with the processing capability of said terminal.

30. A system according to claim 2, wherein said data exchange unit comprises:

compression determination means for determining on the basis of the communication infrastructure data whether data compression is enabled, and

compression means for compressing the service data provided as the application service when said compression determination means determines that data compression is enabled.

31. A system according to claim 5, wherein said second data processing unit comprises:

compression determination means for determining on the basis of the communication infrastructure data whether data compression is enabled, and

compression means for compressing the service data provided as the application service when said compression determination means determines that data compression is enabled.

32. A system according to claim 30 or 31, wherein said compression means changes a compression level in correspondence with the communication capability of said communication network.

33. A system according to claim 3, wherein said data exchange unit comprises:

compression determination means for determining on the basis of the terminal attribute data and the communication infrastructure data whether data compression is enabled, and

compression means for compressing the service data provided as the application service when said compression determination means determines that data compression is enabled.

34. A system according to claim 6, wherein said second data processing unit comprises:

compression determination means for determining on the basis of the terminal attribute data and the communication infrastructure data whether data compression is enabled, and

compression means for compressing the service data provided as the application service when said compression determination means determines that data compression is enabled.

35. A system according to claim 33 or 34, wherein said compression means changes a compression level in correspondence with the processing capability of said terminal and the communication capability of said communication network.

36. A data exchange method comprising the steps of:

arranging a data exchange function in a network connection unit for connecting networks to each other;

determining a processing capability of said terminal on a side of said network connection unit, when service data provided as an application service from a data processing unit to a terminal;

converting the service data into a specific format in correspondence with the processing capability of said terminal, and

controlling the terminal equipment to enable to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

37. A data exchange method comprising the steps of:

arranging a data exchange function in a network connection unit for connecting networks to each other;

determining a communication capability of a communication network connected to said terminal on a side of said network connection unit, when service data provided as an application service from a data processing unit to a terminal;

converting the service data into a specific format in correspondence with the communication capability of said communication network, and

controlling the terminal equipment to enable to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

38. A data exchange method comprising the steps of:

arranging a data exchange function in a network connection unit for connecting networks to each other;

determining a processing capability of said terminal and a communication capability of a communication network connected to said terminal on a side of said network connection unit, when service data provided as an application service from a data processing unit to a terminal;

converting the service data into a specific format in correspondence with the processing capability of said terminal and the communication capability of said communication network, and

controlling the terminal equipment to enable to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

39. A data exchange method in a distributed network computing system including a communication network, a terminal connected to said communication network, a first data processing unit for providing an application service to said terminal, and a second data processing unit connected to said communication network and having a terminal attribute data management section, comprising the computer steps of:

registering terminal attribute data representing a processing capability of said terminal in said terminal attribute data management section;

retrieving said second data processing unit having said terminal attribute data management section;

acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management section in said second data processing unit;

converting service data provided as the application service into a specific format on the basis of the terminal attribute data;

transmitting the converted service data through said communication network, and

controlling the terminal equipment to enable to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

40. A data exchange method in a distributed network computing system including a communication network, a terminal connected to said communication network, a first data processing unit for providing an application service to said terminal, and a second data processing unit connected to said communication network and having a communication infrastructure data management section, comprising the computer steps of:

registering communication infrastructure data representing a communication capability of said communication network in said communication infrastructure data management section;

retrieving said second data processing unit having said communication infrastructure data management section;

acquiring the communication infrastructure data of said communication network connected to said terminal as a communication partner from said communication infrastructure data management section in said second data processing unit;

converting service data provided as the application service into a specific format on the basis of the communication infrastructure data;

transmitting the converted service data through said communication network, and

controlling the terminal equipment to enable to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

41. A data exchange method in a distributed network computing system including a communication network, a terminal connected to said communication network, a first data processing unit for providing an application service to said terminal, and a second data processing unit connected to said communication network and having a terminal attribute data management section and a communication infrastructure data management section, comprising the computer steps of:

registering terminal attribute data representing a processing capability of said terminal in said terminal attribute data management section and registering communication infrastructure data representing a communication capability of said communication network in said communication infrastructure data management section;

retrieving said second data processing unit having said terminal attribute data management section and said communication infrastructure data management section;

acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management section and simultaneously acquiring the communication infrastructure data of said communication network connected to said terminal in said second data processing unit;

converting service data provided as the application service into a specific format on the basis of the terminal attribute data and the communication infrastructure data;

transmitting the converted service data through said communication network, and

controlling the terminal equipment to enable to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

42. A memory media for storing the program information used in a data exchange method claimed in claim 37, 38, 39, 40 or 41 and for reading the stored information by a computer, wherein the memory media is installed to operate in a information processing unit.

43. A data exchange apparatus arranged in a data processing apparatus for providing an application service to a terminal connected through a communication network, comprising:

a terminal attribute data management means for managing terminal attribute data representing a processing capability of said terminal which receive the application service from the data processing apparatus;

a conversion means for a acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management means and converting service data provided as the application service into a specific format on the basis of the terminal attribute data,

a communication means for transmitting through said communication network the service data converted by said communication means, and

a controlling means for enabling the terminal equipment to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

44. A data exchange apparatus arranged in a data processing apparatus for providing an application service to a terminal connected through a communication network, comprising:

a communication infrastructure data management means for managing communication infrastructure data representing a communication capability of said communication network;

a conversion means for acquiring the communication infrastructure data of said communication network connected to said terminal as a communication partner from said communication infrastructure data management means and converting service data provided as the application service into a specific format on the basis of the communication infrastructure data;

a communication means for transmitting through said communication network the service data converted by said communication means, and

a controlling means for enabling the terminal equipment to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

45. A data exchange apparatus arranged in a data processing apparatus for providing an application service to a terminal connected through a communication network, comprising:

a terminal attribute data management means for managing terminal attribute data representing a processing capability of said terminal;

a communication infrastructure data management means for managing communication infrastructure data representing a communication capability of said communication network;

a conversion means for acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management means and simultaneously acquiring the communication infrastructure data of said communication network connected to said terminal from said communication infrastructure data management means, and converting service data provided as the application service into a specific format on the basis of the terminal attribute data and the communication infrastructure data;

a communication means for transmitting through said communication network the service data converted by said communication means, and

a controlling means for enabling the terminal equipment to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions.

46. A data exchange apparatus according to any one of claims 43, 44, and 45, wherein said data exchange unit comprises user interface data management means for managing user interface data representing an operation method unique to each terminal, and

said conversion means obtains user interface data corresponding to said terminal as the communication partner from said user interface data management means and converts the service data provided as the application service into a specific format on the basis of the user interface data.

47. A data exchange apparatus according to any one of claims 43, 44, and 45, wherein said data exchange unit comprises user data management means for managing user data representing an operation method unique to each user, and

said conversion means obtains user data corresponding to said terminal as the communication partner from said user data management means and converts the service data provided as the application service into a specific format on the basis of the user data.

48. A data exchange apparatus according to claim 43, wherein said data exchange unit comprises:

a enciphering determination means for determining on the basis of the terminal attribute data whether data enciphering is enabled, and

an enciphering means for enciphering the service data provided as the application service when said enciphering determination means determines that data enciphering is enabled.

49. A data exchange apparatus according to claim 48, wherein said enciphering means changes an enciphering level in correspondence with the processing capability of said terminal.

50. A data exchange apparatus according to claim 44, wherein said data exchange unit comprises

an enciphering determination means for determining on the basis of the communication infrastructure data whether data enciphering is enabled, and

an enciphering means for enciphering the service data provided as the application service when said enciphering determination means determines that data enciphering is enabled.

51. A data exchange apparatus according to claim 50, wherein said enciphering means changes an enciphering level in correspondence with the communication capability of said communication network.

52. A data exchange apparatus according to claim 45, wherein said data exchange unit comprises:

an enciphering determination means for determining on the basis of the terminal attribute data and the communication infrastructure data whether data enciphering is enabled, and

an enciphering means for enciphering the service data provided as the application service when said enciphering determination means determines that data enciphering is enabled.

53. A data exchange apparatus according to claim 43, wherein said data exchange unit comprises:

a compression determination means for determining on the basis of the terminal attribute data whether data compression is enabled, and

a compression means for compressing the service data provided as the application service when said compression determination means determines that data compression is enabled.

54. A data exchange apparatus according to claim 53, wherein said compression means changes a compression level in correspondence with the processing capability of said terminal.

55. A data exchange apparatus according to claim 44 wherein said data exchange unit comprises:

a compression determination means for determining on the basis of the communication infrastructure data whether data compression is enabled, and

a compression means for compressing the service data provided as the application service when said compression determination means determines that data compression is enabled.

56. A data exchange apparatus according to claim 55, wherein said compression means changes a compression level in correspondence with the communication capability of said communication network.

57. A data exchange apparatus according to claim 56, wherein said data exchange unit comprises:

a compression determination means for determining on the basis of the terminal attribute data and the communication infrastructure data whether data compression is enabled, and

a compression means for compressing the service data provided as the application service when said compression determination means determines that data compression is enabled.

58. A data exchange apparatus according to claim 57, wherein said compression means changes a compression level in correspondence with the processing capability of said terminal and the communication capability of said communication network.

59. A data exchange method in a data processing apparatus for providing an application service to a terminal connected through a communication network, comprising the steps of:

registering terminal attribute data representing a processing capability of said terminal in a terminal attribute data management section;

analyzing service data described in a structured document format as a component data format;

acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management section;

converting the analyzed service data into a specific format on the basis of the terminal attribute data; and

controlling the terminal equipment to enable to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions, in advance of transmitting the converted service data through said communication network after converting the service data provided as an application service into a specific format on the basis of the terminal attribute data.

60. A data exchange method in a data processing apparatus for providing an application service to a terminal connected through a communication network, comprising the steps of:

registering communication infrastructure data representing a communication capability of said communication network in a communication infrastructure data management section;

analyzing service data described in a structured document format as a component data format;

acquiring the communication infrastructure data of said communication network connected to said terminal as a communication partner from said communication infrastructure data management section;

converting the analyzed service data into a specific format on the basis of the communication infrastructure data; and

controlling the terminal equipment to enable to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions in advance of transmitting the converted service data through said communication network.

61. A data exchange method in a data processing apparatus for providing an application service to a terminal connected through a communication network, comprising the steps of:

registering terminal attribute data representing a processing capability of said terminal in a terminal attribute data management section;

registering communication infrastructure data representing a communication capability of said communication network in a communication infrastructure data management section;

analyzing service data described in a structured document format as a component data format;

acquiring the terminal attribute data of said terminal as a communication partner from said terminal attribute data management section and simultaneously acquiring the communication infrastructure data of said communication network connected to said terminal from said communication infrastructure data management section;

converting the analyzed service data into a specific format on the basis of the terminal attribute data and the communication infrastructure data; and

controlling the terminal equipment to enable to decipher said specific data, when said data exchange unit is connected with said terminal through said network and said terminal equipment requests an access to specific data by satisfying the specified conditions in advance of transmitting the converted service data through said communication network.

62. A method according to any one of claims 59, 60, or 61, further comprising converting service data described in a non-component data format into the component data format, analyzing the service data described in the component data format, and performing data exchange.

63. A memory media for storing the program information used in a data exchange method claimed in claim 59, 60, 61, or 62 and for reading the stored information by a computer, wherein the memory media is installed to operate in a information processing unit.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a distributed network computing system for connecting a plurality of terminals and, more particularly, to a distributed network computing system having a security function for providing an application service such as an inventory control service to various terminals such as PDAs, personal computers (PCs), and portable PCs having different processing capabilities and connected to a plurality of communication networks including a public network, a wired LAN (Local Area Network), and a wireless LAN.

The present invention also relates to data exchange apparatus having a security function.

A centralized processing system is the mainstream of conventional data processing using computers in which a plurality of terminals are connected to one main computer. On the contrary, in a distributed processing system, a plurality of computers are connected with each other to form a network so that computers may share their resources with each other to perform efficient processing. An environment for allowing distributed processing of an application among the computers of different types is called a distributed computing environment.

In the distributed computing environment, an user need not be aware of a location of a program or data. Logically, since the entire network acts as if it were one computer system, the user can utilize desired data or function in the network.

Assume a system for providing an application service such as an inventory control service to each terminal in the network. The user terminals have different processing capabilities which is, hereinafter, called a terminal attribute, the meaning of which includes the capability of the CPU, the display screen size and the memory capacity. To adjust and absorb the difference, a manual processing of data must be performed on the terminal side or on the server side.

Each terminal is connected to different communication networks, such as a public telephone or data network and a wired or wireless LAN (Local Area Network). Therefore, the data transmission rate, the transmission volume, and the transmission quality vary with each communication network as a communication infrastructure.

Generally, assuming that a personal computer (PC) has a high-level processing capability as a general-purpose device, a PDA has an intermediate-level processing capability and other terminals have a low-level processing capability. With respect to the communication infrastructures, the transmission volume and quality of a wired or wireless LAN are maintained at a high level. Those of an ISDN (Integrated Services Digital Network) are maintained at an intermediate level, and those of an analog wired network, or an analog or digital wireless network are maintained at a low level.

In the network environment, the processing capability varies from a terminal to terminal and the communication capability varies among communication infrastructures. Therefore, it is very difficult to uniformly provide an application service to various terminals in such an environment.

Generally, the attribute of each terminal used in the system is determined at a time of system designing, and the application service is provided in accordance with the attribute. For this reason, even when a terminal having a new attribute has been developed, the terminal can hardly be introduced into the system for use.

To provide a service while adjusting the difference in processing capability among the terminals or the difference in communication capability among the communication infrastructures, cumbersome processing must be performed. Accordingly, a large server computer having an adequate capability is required.

An establishment such as a company or a factory must be equipped with an exchange system for performing exchange/connection between extension telephones and between an extension telephone and a subscriber telephone line (main wire). Generally, a private exchange system or private exchange equipment is referred to as a PBX (Private Branch exchange) and, particularly, a digital private exchange system is called as a digital PBX. The digital PBX converts an analog speech signal into a digital signal and processes the converted digital signal. When OA devices such as a personal computer, a word processor, and other types of computers used in the office are connected to the digital PBX, data and speech signals can be uniquely and efficiently processed. In addition, when various network functions are added to the digital PBX, a wide area network can be constructed by an intra office communication network.

When a LAN is constructed for the first time, several computing devices are connected to one Ethernet cable (coaxial cable) in many cases. However, as the network expands and the number of connected devices increases, the physical length of the cable reaches the limit. A router is used as a means for physically and logically expanding the network beyond the limit of the cable.

The router can construct a network having a closed loop. The router determines an optimum route (routing) and allow only necessary packets passes therethrough. The router determines the route by a network number in an internet protocol (network layer) and then determines the route by a node number there by determining the final destination.

Since the internet protocol in the network layer is defined differently by different protocols such as TCP/IP OSI etc., the router basically supports one protocol. In other words, the router can select an only network corresponding to the selected protocol from backbone networks including a plurality of protocols. For this reason, the router can be effectively used to meet a requirement for a decrease in load factor from the Ethernet to the public line due to the speed.

Conventionally, however, no system has been proposed yet to provide the service while adjusting the difference in processing capability among the terminals or the difference in communication capability among the communication infrastructures on a network connection apparatus such as an exchange system or a router.

Moreover, it is necessary to complete a various kinds of security functions under the network computing environment. Conventionally, research and development on encryption technology has been done with respect to security of data. For example, research and development on encryption of data on a communication line has been done conventionally as well as on verification technology. Taking the network computing environment in which terminals such as portable PCs (clients) are used into consideration, any measures specific to such environment must be taken against an accidental leaving or being stolen of the portable PCs. The problems are, however, not been solved by the simple encryption technology on the communication line. It has been, thus, very inconvenient that no effective means have not been provided conventionally.

On the other hand, a system for managing a large quantity of data is necessary. In the WWW (World Wide Web) which is becoming popular on the internet, a structuring language (tag language) called HTML (Hyper Text Markup Language) is used. As a structuring language other than HTML, SGML (Standard Generalized Markup Language) may be widely used along with the spread of CALS (Continuous Acquisition and Lifecycle Support).

To display a document written in the structuring language, a function (browser) of analyzing and displaying the structuring language is required on the terminal side. In other words, data described in the structuring language cannot be provided to a terminal without the browser function.

When data described in the structuring language is directly transmitted on the network, a large quantity of data is transmitted even through a line having a low transmission capability, and this transmission takes a long time. These problems also apply to a component data format such as OLE (Object Linking and Embedding) in addition to HTML.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to provide a distributed network computing system capable of providing, in a network environment with various terminals, an application service corresponding to the processing capability of each terminal, and even when a plurality of communication infrastructures exist, providing an application service corresponding to the communication capability of each communication infrastructure, and a data exchange apparatus, a method and a storage medium each of which has a security function and is used in this system.

It is another object of the present invention to provide a distributed network computing system capable of providing, in a network environment with various terminals, an application service corresponding to the processing capability of each terminal without using any large server computer, and even when a plurality of communication infrastructures exist, providing an application service corresponding to the communication capability of each communication infrastructure, and a data exchange apparatus, a method and a storage medium each of which has a security function and is used in this system.

It is still another object of the present invention to provide a distributed network computing system capable of providing, in a network environment with various terminals, an application service corresponding to the processing capability of each terminal when data described by a component data format such as a structured document is provided as the application service, and even when a plurality of communication infrastructures exist, to provide an application service corresponding to the communication capability of each communication infrastructure, and a data exchange apparatus, a method and a storage medium each of which has a security function and is used in this system.

It is still another object of the present invention to provide a distributed network computing system capable of providing, in a network environment with various terminals, a servicewhile adjusting differences in processing capability among terminals or differences in communication capability among communication infrastructures on a network connecting apparatus such as an exchange system or a router, and a data exchange apparatus, a method and a storage medium each of which has a security function and is used in this system.

It is still another object of the present invention to provide a distributed network computing system with a complete security function, in a network environment with various terminals, and a data exchange apparatus, a method and a storage medium each of which has a security function and is used in this system.

(1) According to the present invention, in a distributed network computing system including a data processing unit for providing an application service of various application software, a terminal for receiving the application service from the data processing unit, and a communication network which connects the data processing unit and the terminal, a data exchange unit is arranged in the data processing unit.

This data exchange unit comprises terminal attribute data management means for managing terminal attribute data representing a processing capability of the terminal, conversion means for acquiring the terminal attribute data of the terminal as a communication partner from the terminal attribute data management means and converting service data provided as the application service into a specific format on the basis of the terminal attribute data, and communication means for transmitting through the communication network the service data converted by the communication means.

Furthermore, the data exchange unit has a feature that it controls a terminal which is connected to the data exchange unit to be able to read a particular data when the terminal satisfies a prescribed condition and it requests to access the particular data.

According to this arrangement, when a plurality of terminals are present on a network, service data provided by the data processing unit is converted in correspondence with the processing capability of each terminal. In this case, the data exchange process means processing of changing the format of certain data in correspondence with the processing capability of a terminal as a communication partner. For example, in transmitting image data (image), if the partner terminal has no image processing capability, the image data is converted into symbol data and transmitted.

With this processing, a terminal (e.g., a PDA (Personal Digital Assistants)) which is excellent in portability but poor in data processing capability (arithmetic capability) or screen display/user interface providing capability relative to other terminals (e.g., PCs) can be used to constitute a distributed network computing system. The terminal can receive the same service as that for the remaining terminals although the data format is different.

Particularly, when this data exchange process is performed by network connection means (e.g., a line exchange system or a router), the data can be converted into a final format near the user terminal. More specifically, when a network is constituted by sub-networks, the data exchange process can be performed in correspondence with the sub-network.

In addition, when a function of managing terminal attribute data necessary for data exchange is distributed to a second data processing unit (server computer), the processing load on the first data processing unit can be reduced, thus realizing a fail-safe system and security function can be improved.

(2) According to the present invention, in a distributed network computing system including a data processing unit for providing an application service of various application software, a terminal for receiving the application service from the data processing unit, and a communication network which connects the data processing unit and the terminal, a data exchange unit is arranged in the data processing unit.

This data exchange unit comprises communication infrastructure data management means for managing communication infrastructure data representing a communication capability of the communication network, conversion means for acquiring the communication infrastructure data of the communication network connected to the terminal as a communication partner from the communication infrastructure data management means and converting service data provided as the application service into a specific format on the basis of the communication infrastructure data, and communication means for transmitting through the communication network the service data converted by the communication means.

Furthermore, the data exchange unit has a feature that it controls a terminal which is connected to the data exchange unit to be able to read a particular data when the terminal satisfies a prescribed condition and it requests to access the particular data.

According to this arrangement, when a plurality of communication networks are present on a network, service data provided by the data processing unit is converted in correspondence with the communication capability of each communication network. In this case, the data exchange process means processing of changing the format of certain data in correspondence with the communication capability of a communication network connected to a terminal as a communication partner. For example, if the data transmission capability of the communication network is high, the data is enciphered and transmitted. If the data transmission capability is low, the transmission data size is changed by converting binary data into text data, converting format data such as centering into a blank character, or neglecting the font data, and thereafter, the data is transmitted. When the data transmission capability is low, and the terminal side has an appropriate arithmetic capability, the data may be compressed and transmitted.

With this processing, even in a system having various communication infrastructures, the relative difference in data transmission rate/volume/quality among the communication infrastructures can be absorbed. The terminal can receive the same service as that for the remaining terminals although the data format is different. Further, the terminal can be improved in its security function.

(3) According to the present invention, in a distributed network computing system including a data processing unit for providing an application service of various application software, a terminal for receiving the application service from the data processing unit, and a communication network which connects the data processing unit and the terminal, a data exchange unit is arranged in the data processing unit.

This data exchange unit comprises terminal attribute data management means for managing terminal attribute data representing a processing capability of the terminal, communication infrastructure data management means for managing communication infrastructure data representing a communication capability of the communication network, conversion means for acquiring the terminal attribute data of the terminal as a communication partner from the terminal attribute data management means and simultaneously acquiring the communication infrastructure data of the communication network connected to the terminal from the communication infrastructure data management means, and converting service data provided as the application service into a specific format on the basis of the terminal attribute data and the communication infrastructure data, and communication means for transmitting through the communication network the service data converted by the communication means.

Furthermore, the data exchange unit has a feature that it controls a terminal which is connected to the data exchange unit to be able to read a particular data when the terminal satisfies a prescribed condition and it requests to access the particular data.

According to this arrangement, when a plurality of terminals and a plurality of communication networks are present on a network, service data provided by the data processing unit is converted in correspondence with the processing capability of each terminal and the communication capability of each communication network. In this case, the data exchange process means processing of changing the format of certain data in correspondence with the processing capability of a terminal as a communication partner and the communication capability of a communication network connected to the terminal.

With this processing, even in a system having various communication infrastructures, the relative difference in data transmission rate/volume/quality among the communication infrastructures can be absorbed. The terminal can receive the same service as that for the remaining terminals although the data format is different. Further, the terminal can be improved in its security function.

(4) According to the present invention, in a distributed network computing system including a first data processing unit for providing an application service, a terminal for receiving the application service from the first data processing unit, and a communication network which connects the first data processing unit and the terminal, communication infrastructure data management means for managing communication infrastructure data representing a communication capability of the communication network is arranged in a second data processing unit connected to the communication network independently of the first data processing unit.

The first data processing unit comprises retrieval means for retrieving the second data processing unit having the communication infrastructure data management means from one or a plurality of second data processing units, conversion means for acquiring the communication infrastructure data corresponding to the terminal as a communication partner from the communication infrastructure data management means and converting service data provided as the application service into a specific format on the basis of the communication infrastructure data in the second data processing unit retrieved by the retrieval means, communication means for transmitting through the communication network the service data converted by the conversion means, and a control means for controlling the terminal which is connected to the data exchange unit to be able to read a particular data when the terminal satisfies a prescribed condition and it requests to access the particular data.

According to this arrangement, when a plurality of communication networks are present on a network, service data provided by the first data processing unit (main server computer for providing the application service) is converted in correspondence with the communication capability of each communication network. In this case, the data exchange process means processing of changing the format of certain data in correspondence with the communication capability of a communication network connected to a terminal as a communication partner.

When an image data is transmitted, it is transmitted to a terminal by converting it into a symbol data if the terminal to which the data is transmitted does not have capability of image processing.

The distributed network computing system, thus, can be constructed using such terminals as personal digital assistants (PDA) which is superior in carrying but inferior in capability of information processing or calculating and of providing display or user interface to such other type of terminals as personal computers (PCs). Terminals, thus, can receive similar services which other type of terminals can receive even if the data format is different from each other.

In addition, when a function of managing communication infrastructure data necessary for data exchange is distributed to the second data processing unit (sub-server computer), the processing load on the first data processing unit can be reduced, thus realizing a fail-safe system. Moreover, a system can be realized which is not affected by hindrances and is improved in security function.

(5) According to the present invention, in a distributed network computing system including a first data processing unit for providing an application service, a terminal for receiving the application service from the first data processing unit, and a communication network which connects the first data processing unit and the terminal, communication infrastructure data management means for managing communication infrastructure data representing a communication capability of the communication network are arranged in a second data processing unit connected to the communication network independently of the first data processing unit.

The first data processing unit comprises retrieval means for retrieving the second data processing unit having the communication infrastructure data management means from one or a plurality of second data processing units, conversion means for acquiring the communication infrastructure data corresponding to the terminal as the communication partner from the communication infrastructure data management means, and converting service data provided as the application service into a specific format on the basis of the communication infrastructure data in the second data processing unit retrieved by the retrieval means, and communication means for transmitting through the communication network the service data converted by the conversion means, and a control means for controlling the terminal which is connected to the data exchange unit to be able to read a particular data when the terminal satisfies a prescribed condition and it requests to access the particular data.

With this arrangement, a service data provided by the first data processing unit which is a main server computer providing application services is converted into a service data having a different format corresponding to a communication capability of each one of plurality of different kind of networks forming a network. The conversion of format of the service data means, in this case, that a format of a data is converted into another format in accordance with the capability of the network to which a terminal on the other side is connected. For example, data is transmitted after it is compressed or encoded if the communication network has a high data transmission capability and data is transmitted after it is converted from a binary data to a text data, after it is changed from such a format data as "centering" into a blank character or after it is changed in size by ignoring a font information and the like if the communication network has a low data transmission capability. In addition, data can be compressed and transmitted to the terminal connected to the communication network having a low data transmission capability if the terminal has a sufficient calculation capability.

Even the distributed network computing system in which various kind of communication infrastructures coexist, relative difference of data transmission speed, quantity or quality among the communication infrastructures can be adjusted.

On the terminal sides, each terminal can receive similar services to those which are received by other terminals even though their format is different from each other.

In addition, when a function of managing communication infrastructure data necessary for data exchange is distributed to the second data processing unit (sub-server computer), the processing load on the first data processing unit can be reduced, thus realizing a fail-safe system. Moreover, a system can be realized which is not affected by hindrances and is improved in security function.

With this arrangement, when a function of managing terminal attribute data or communication infrastructure data necessary for data exchange is distributed to the second data processing unit (sub-server computer), the processing load on the first data processing unit can be reduced, thus realizing a fail-safe system.

(6) According to the present invention, in a distributed network computing system including a first data processing unit for providing an application service, a terminal for receiving the application service from the first data processing unit, and a communication network which connects the first data processing unit and the terminal, terminal attribute data management means for managing terminal attribute data representing a processing capability of the terminal and communication infrastructure data management means for managing communication infrastructure data representing a communication capability of the communication network are arranged in a second data processing unit connected to the communication network independently of the first data processing unit.

The first data processing unit comprises retrieval means for retrieving the second data processing unit having the terminal attribute data management means and the communication infrastructure data management means from one or a plurality of second data processing units, conversion means for acquiring the terminal attribute data of the terminal as a communication partner from the terminal attribute data management means and simultaneously acquiring the communication infrastructure data corresponding to the terminal as the communication partner from the communication infrastructure data management means, and converting service data provided as the application service into a specific format on the basis of the terminal attribute data and the communication infrastructure data in the second data processing unit retrieved by the retrieval means, and communication means for transmitting through the communication network the service data converted by the conversion means, and a control means for controlling the terminal which is connected to the data exchange unit to be able to read a particular data when the terminal satisfies a prescribed condition and it requests to access the particular data.

With this arrangement, a service data provided by the first data processing unit which is a main server computer providing application services is converted into a service data having a different format corresponding to a data processing capability of each terminal a communication capability of each one of plurality of different kind of networks forming a network. The conversion of format of the service data means, in this case, that a format of a data is converted into another format in accordance with the capability of the network to which a terminal on the other side is connected.

The distributed network computing system, thus, can be constructed using such terminals as personal digital assistants (PDA) which is superior in carrying but inferior in capability of information processing or calculating and of providing display or user interface to such other type of terminals as personal computers (PCs). Terminals, thus, can receive similar services which other type of terminals can receive even if the data format is different from each other. With this processing, even in a system having various communication infrastructures, the relative difference in data transmission rate/volume/quality among the communication infrastructures can be absorbed. The terminal can receive the same service as that for the remaining terminals although the data format is different. The conversion of format of the service data means, in this case, that a format of a data is converted into another format in accordance with the capability of the network to which a terminal on the other side is connected.

In addition, when a function of managing communication infrastructure data necessary for data exchange is distributed to the second data processing unit (sub-server computer), the processing load on the first data processing unit can be reduced, thus realizing a fail-safe system. Moreover, a system can be realized which is not affected by hindrances and is improved in security function.

(7) According to the present invention, in a distributed network computing system including a data processing unit for providing an application service of various application software, a terminal for receiving the application service from the data processing unit, and a communication network which connects the data processing unit and the terminal, a data exchange unit is arranged in the data processing unit.

This data exchange unit comprises terminal attribute data management means for managing terminal attribute data representing a processing capability of the terminal, conversion means for acquiring the terminal attribute data of the terminal as a communication partner from the terminal attribute data management means and converting service data provided as the application service into a specific format on the basis of the terminal attribute data, communication means for transmitting through the communication network the service data converted by the communication means and a control means for controlling the terminal which is connected to the data exchange unit to be able to read a particular data when the terminal satisfies a prescribed condition and it requests to access the particular data.

According to this arrangement, when a plurality of terminals are present on a network, service data provided by the data processing unit is converted in correspondence with the processing capability of each terminal. In this case, the data exchange process means processing of changing the format of certain data in correspondence with the processing capability of a terminal as a communication partner. For example, in transmitting image data (image), if the partner terminal has no image processing capability, the image data is converted into symbol data and is transmitted.

With this processing, a terminal which is excellent in portability but poor in data processing capability (arithmetic capability) or screen display/user interface providing capability relative to other terminals (e.g., PCs) can be used to constitute a distributed network computing system. The terminal can receive the same service as that for the remaining terminals although the data format is different.

Particularly, when this data exchange process is performed by network connection means (e.g., a line exchange system or a router), the data can be converted into a final format near the user terminal. More specifically, when a network is constituted by subnetworks, the data exchange process can be performed in correspondence with the sub-network.

(8) According to the present invention, in a distributed network computing system including a data processing unit for providing an application service of various application software, a terminal for receiving the application service from the data processing unit, and a communication network which connects the data processing unit and the terminal, a data exchange unit is arranged in the data processing unit.

This data exchange unit comprises communication infrastructure data management means for managing communication infrastructure data representing a communication capability of the communication network, conversion means for acquiring the communication infrastructure data of the communication network connected to the terminal as a communication partner from the communication infrastructure data management means and converting service data provided as the application service into a specific format on the basis of the communication infrastructure data, and communication means for transmitting through the communication network the service data converted by the communication means.

According to this arrangement, when a plurality of communication networks are present on a network, service data provided by the data processing unit is converted in correspondence with the communication capability of each communication network. In this case, the data exchange process means processing of changing the format of certain data in correspondence with the communication capability of a communication network connected to a terminal as a communication partner. For example, if the data transmission capability of the communication network is high, the data is enciphered and transmitted. If the data transmission capability is low, the transmission data size is changed by converting binary data into text data, converting format data such as centering into a blank character, or neglecting the font data, and thereafter, the data is transmitted. When the data transmission capability is low, and the terminal side has an appropriate arithmetic capability, the data may be compressed and transmitted.

With this processing, even in a system having various communication infrastructures, the relative difference in data transmission rate/volume/quality among the communication infrastructures can be absorbed. The terminal can receive the same service as that for the remaining terminals although the data format is different. Further, the terminal can be improved in its security function.

Particularly, when this data exchange process is performed by network connection means (e.g., a line exchange system or a router), the data can be converted into a final format near the user terminal. More specifically, when a network is constituted by subnetworks, the data exchange process can be performed in correspondence with the sub-network with security function being improved.

(9) According to the present invention, a data exchange unit is arranged in the network connecting means which connects networks with each other in a distributed network computing system including a data processing unit for providing an application service of various application software, a terminal for receiving the application service from the data processing unit, and a communication network which connects the data processing unit and the terminal.

This data exchange unit comprises terminal attribute data management means for managing terminal attribute data representing a processing capability of the terminal, communication infrastructure data management means for managing communication infrastructure data representing a communication capability of the communication network, conversion means for acquiring the terminal attribute data of the terminal as a communication partner from the terminal attribute data management means and simultaneously acquiring the communication infrastructure data of the communication network connected to the terminal from the communication infrastructure data management means, and converting service data provided as the application service into a specific format on the basis of the terminal attribute data and the communication infrastructure data, and communication means for transmitting through the communication network the service data converted by the communication means.

Furthermore, the data exchange unit has a feature that it controls a terminal which is connected to the data exchange unit to be able to read a particular data when the terminal satisfies a prescribed condition and it requests to access the particular data.

According to this arrangement, when a plurality of terminals and a plurality of communication networks are present on a network, service data provided by the data processing unit is converted in correspondence with the processing capability of each terminal and the communication capability of each communication network. In this case, the data exchange process means processing of changing the format of certain data in correspondence with the processing capability of a terminal as a communication partner and the communication capability of a communication network connected to the terminal.

With this processing, a terminal which is excellent in portability but poor in data processing capability (arithmetic capability) or screen display/user interface providing capability relative to other terminals (e.g., PCs) can be used to constitute a distributed network computing system. The terminal can receive the same service as that for the remaining terminals although the data format is different.

Particularly, when this data exchange process is performed by network connection means (e.g., a line exchange system or a router), the data can be converted into a final format near the user terminal. More specifically, when a network is constituted by sub-networks, the data exchange process can be performed in correspondence with the sub-network.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a block diagram showing the structure of a distributed network computing system according to an embodiment of the present invention;

FIG. 2 is a block diagram showing the internal structure of a data exchange process section in a data exchange apparatus;

FIG. 3 is a block diagram showing the internal structure of a terminal data management section in the data exchange apparatus;

FIG. 4 is a block diagram showing the internal structure of a user interface data management section in the data exchange apparatus;

FIG. 5 is a block diagram showing the internal structure of a user data management section in the data exchange apparatus;

FIG. 6 is a block diagram showing the internal structure of a communication infrastructure data management section in the data exchange apparatus;

FIG. 7 is a flow chart showing a general application service processing operation;

FIG. 8 is a flow chart showing an application service processing operation using the data exchange apparatus;

FIG. 9 is a view showing a protocol sequence for determining a terminal attribute;

FIG. 10 is a flow chart showing a data exchange process operation corresponding to the terminal attribute;

FIG. 11 is a flow chart showing a data exchange process operation corresponding to a communication infrastructure;

FIG. 12 is a flow chart showing a data enciphering processing operation;

FIG. 13 is a flow chart showing a data compression processing operation;

FIG. 14 is a flow chart showing a processing operation in utilization of the application service using an I/O unit;

FIG. 15 is a view showing the concept of an entire system including an application service on the assumption of a structured document;

FIG. 16 is a view showing an example of the structured document shown in FIG. 15;

FIG. 17 is a flow chart showing a processing operation corresponding to a terminal attribute in use of the structured document;

FIG. 18 is a flow chart showing a processing operation corresponding to a communication infrastructure attribute in use of the structured document;

FIG. 19 is a flow chart showing a processing operation corresponding to the terminal attribute and the communication infrastructure attribute in use of the structured document;

FIG. 20 is a flow chart showing a processing operation for service data other than the structured document format;

FIG. 21 is a view showing an example an actual display of the structured document shown in FIG. 16.

FIG. 22 is a flowchart showing a data renewal processing operation on server.

FIG. 23 is a flowchart showing a process of requesting for and receiving a copy of data.

FIG. 24 is a flowchart showing a process for data copying on terminal equipment.

FIG. 24 is a flowchart showing a process for data copying on terminal equipment.

FIG. 25 is a flowchart showing a process for transmitting a symbol data.

FIG. 26 is a flowchart showing a process for data re-transmitting of a data.

FIG. 27 is a flowchart showing a process for extracting attribute data of received mail.

FIG. 28 is a flowchart showing a process for exchanging data with a portable personal telephone.

FIG. 29 is a flowchart showing a process of the server, when printing paper is not available.

FIG. 30 is a flowchart showing a process for changing an original data.

FIG. 31 is a flowchart showing a process for transmission of a notice of data change.

FIG. 32 is a flowchart showing a process for transmission of a notice of data change in relation to FIG. 31.

FIG. 33 is a drawing showing the outline of structure of resources on terminal equipment side.

FIG. 34 is a flowchart showing a security function.

FIG. 35 is a flowchart showing change of an verification key on the side of data exchange unit.

FIG. 36 is a drawing for explaining the enciphering system.

FIG. 37 is a flowchart showing a decoding process.

FIG. 38 is a drawing showing a structure of a system of the servers with distributed data exchange function, which are connected through networks.

FIG. 39 is a block diagram showing the structure of a distributed network computing system according to the second embodiment of the present invention;

FIG. 40 is a flow chart showing a service providing process operation by distributed processing in the second embodiment shown in FIG. 39;

FIG. 41 is a block diagram showing the structure of an integrated server in case wherein a data exchange apparatus according to the third embodiment of the present invention is realized on an exchange system;

FIG. 42 is a block diagram showing the structure of an exchange function section of a line exchange system in the third embodiment shown in FIG. 41;

FIG. 43 is a block diagram showing the structure of a distributed network computing system according to the third embodiment of the present invention; and

FIGS. 44A and 44B are block diagrams for explaining processing operations performed when a PBX in the third embodiment has a data exchange function.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention will be described below with reference to the accompanying drawing.

FIG. 1 is a block diagram showing the structure of a distributed network computing system according to an embodiment of the present invention. Referring to FIG. 1, reference numeral 1 denotes a server constituted by a general-purpose computer having a high processing capability.

The server 1 is set in an office. The server 1 has an application service section 20 for providing various application services (application software) such as an inventory control service to each terminal. The services provided by the application service section 20 can be utilized by using an image reader 43 or a printer 42 (to be described later) as an I/O unit.

The server 1 is connected to three communication networks (to be referred to as communication infrastructures hereinafter) having different communication capabilities, i.e., a public network 30, a wired LAN (Local Area Network) 40, and a wireless LAN 50.

The public network 30 is connected to a personal digital assistants (PDS) 31, a handy phone 32, a pager 33, a facsimile apparatus (FAX) 34. The public network 30 is an analog or digital communication network. The data transmission volume of an analog communication network is generally smaller than that of a digital communication network. The PDA 31 is connected to the server 1 through a mobile communication network contained in the public network 30. The quality of mobile communication is low not only because the data transmission volume is small but also because line disconnection or a data transmission error readily occurs due to the mobility. In this embodiment, the PDA 31 gives prominence to the portability. Accordingly, the screen size/control function is low, and only text data can be used. The processing capability of the CPU is lower than that of a personal computer. In addition, the PDA 31 has no external storage unit.

The wired LAN 40 is connected to a personal computer (to be referred to as a PC hereinafter) 41, the printer 42, and the image reader 43. The wired LAN 40 generally has a large transmission data volume and a stable line quality relative to radio communication such as a handy phone service. A current distributed network application service oriented to a general office is often designed in correspondence with the wired LAN 40.

The printer 42 and the image reader 43 are set as output/input devices in the office building. For, e.g., an inventory control service, an inventory slip is read by the image reader 43, the readout data is sent to the server 1 through the wired LAN 40, and the spreadsheet result is output from the printer 42.

A portable PC 51 is connected to the wireless LAN 50. The wireless LAN 50 has almost the same processing capability as that of the wired LAN 40. However, the processing capability of the portable PC 51 connected to the wireless LAN 50 is lower than that of the PC 41 connected to the wired LAN 40.

As described above, in the network environment, the processing capability changes in units of terminals, and the communication capability also changes in units of communication infrastructures.

In this embodiment, a data exchange unit 10 is arranged in the server 1 such that the attributes (the difference in processing capability and the difference in communication capability) of various terminals and communication infrastructures on the network are absorbed.

The data exchange unit 10 is constituted by a data exchange process section 11, a terminal data management section 12, a user interface data management section 13 of application service, a user data management section 14, and a communication infrastructure data management section 15.

Further, the server 1 is connected to a floppy disk drive (FDD) 181, a hard disk drive (HDD) 185, opto-electronic disk memory drive (CD-ROM Drive) 183 by means of bus. The programs shown by the flowcharts in FIGS. 7, 8, 10-14, 17-31 as well as FIG. 33 and FIG. 34 can be stored in diskette 182 of FDD 181, magnetic disk of HDD 185 and CD 184 of CD-ROM Device 183.

The structures of various sections of the data exchange unit 10 will be described below with reference to FIG. 2 to 8.

FIG. 2 is a block diagram showing the internal structure of the data exchange process section 11. The data exchange process section 11 performs a series of processing operations to convert data as an application service into another data in correspondence with the attribute of each terminal or communication infrastructure. The data exchange process section 11 is constituted by a communication interface 111 for inside of data exchange unit, a terminal type determining section 112, a data exchange executing section 113, an intra server user data management section 114, a compression/enciphering processing section 115, a communication interface 116 for outside of data exchange unit, a data change management section 1101, a data renewal management section 1102, a retransmission management section, a priority management section 1104 and, a terminal control section 1105.

The communication interface 111 for inside of data exchange unit is an interface for communication with another element in the data exchange unit 10. The terminal type determining section 112 determines the type of a user terminal (e.g., a large-screen desktop PC, a portable small-screen sub-notebook PC, a PDA). The data exchange executing section 113 executes an actual data exchange process (dissolving, retrieval, extraction, and reprocessing of data). The intra server user data management section 114 manages user data registered in the server 1. The compression/enciphering processing section 115 compresses or enciphers communication data in accordance with the determination result of the terminal type determining section 112 in communication with an external device outside the data exchange unit 10. The communication interface 116 for outside of data exchange unit is an interface for communication with an external device outside the data exchange unit 10.

A data change management section serves to inform a terminal equipment which relates to the data, of a data change, when the data stored in the server 1 has been changed, and has a function to take a countermeasure for the data change. A data renewal management section 1102 is connected to an inside communication interface of a data exchange unit and a compression/enciphering processing section 115, and performs control and processing to transmit the data renewal information on the document data/user data stored at the server 1 by using structured language and the image data converted to symbol data as well as to perform the control of transmission of the other above-mentioned data to outside. The retransmission control section 1103, together with a retransmission/disconnection treatment section 153, performs the retransmission control of the data, when the data transmission to terminal equipment is failed. In other words, the retransmission control section 1103 is so constructed as to set the interval for retransmission after several minutes in case that the line for the receiver is busy, as well as to shorten the transmission time by reprocessing of data or by making the data size compact by compressing under the control of a data exchange execution section 113 and/or a compression/enciphering processing section 115 in case that retransmission shall be made due to a packet failure in packet communication. A priority management section performs the control and execution of the transmission means based upon the determination of the priority rate of the transmission. Furthermore, a data exchange process section 11 is equipped with a terminal control section 1105, which functions to make a continuation of the service possible by supervising the status of the terminals, even if trouble takes place on the side of the terminals.

FIG. 3 is a block diagram showing the internal structure of the terminal data management section 12. The terminal data management section 12 manages attribute data representing the processing capability such as a CPU capability, a display capability, and a memory capacity of each terminal connected to the server 1. The terminal data management section 12 is constituted by a communication interface 121 for inside of data exchange unit, a terminal attribute negotiating section 122, and a terminal attribute data management section 123.

The communication interface 121 for inside of data exchange unit is an interface for communication with another element in the data exchange unit 10. The terminal attribute negotiating section 122 is an interface for various communications, i.e., negotiations about the terminal attribute between the terminal data management section 12 and the terminal. The terminal attribute data management section 123 manages/operates a terminal attribute table in which terminal attribute data of each terminal is registered.

FIG. 4 is a block diagram showing the internal structure of the user interface data management section 13. When the user utilizes the application service, the method of operating the application service changes depending on the terminal, e.g., an icon or a button is operated, or a command is input on the terminal. The user interface data management section 13 manages user interface data representing an operation method unique to each terminal for the application service. The user interface data management section 13 is constituted by a communication interface 131 for inside of data exchange unit and an application service interface table management section 132.

The communication interface 131 for inside of data exchange unit is an interface for communication with another element in the data exchange unit 10. The application service interface table management section 132 manages data (e.g., an operating method for each terminal) associated with the user interface of each application service.

FIG. 5 is a block diagram showing the internal structure of the user data management section 14. In use of an application service, the preference for, e.g., screen display changes depending on the user. For example, a display object such as a graph is arbitrarily moved to a position with a better view on the terminal. The user data management section 14 manages user data representing an operation method unique to each user, including the preference for screen display in use of the application service (in this case, the user data is registered in the server in advance). The user data management section 14 is constituted by a communication interface 141 for inside of data exchange unit, a user data table management section 142, and a user certification section 143.

The communication interface 141 is an interface for communication with another element in the data exchange unit 10. The user data table management section 142 manages associated data including the user name, the user and the terminal name, the address, and the type of communication infrastructure. The user certification section 143 operates when a user certification is required in the data exchange unit 10.

FIG. 6 is a block diagram showing the internal structure of the communication infrastructure data management section 15. The communication infrastructure data management section 15 manages attribute data representing the communication capability such as the data transmission rate, the transmission volume, and the quality of each communication network. The communication infrastructure data management section 15 is constituted by a communication interface 151 for inside of data exchange unit, a communication infrastructure feature management section 152, and a retransmission/disconnection treatment management section 153.

The communication interface 151 is an interface for communication with another element in the data exchange unit 10. The communication infrastructure feature management section 152 manages feature data including the transmission quality and the transmission rate of the communication infrastructure. The retransmission/disconnection treatment management section 153 has a function of performing a retransmission/disconnection treatment in correspondence with the communication infrastructure in use.

The operation of this embodiment will be described below.

A general processing operation of an application service, e.g., an inventory control service without using the data exchange unit 10 will be described first.

FIG. 7 is a flow chart showing a general application service processing operation. The server 1 receives data from the image reader 43 through the wired LAN 40 and transfers data of, e.g., an inventory slip to the application service section 20 (step A11). In the server 1, the application service section 20 extracts a necessary inventory amount from the slip data read by the image reader 43, and displays the contents on the display screen of, e.g., the PC 41 for the user of the PC 41 (step A12).

With this display, the user processes the data, e.g., updates the inventory amount to the latest data, using the PC 41 connected to the server 1 (step A13). Upon receiving the corrected data from the user, the application service section 20 outputs the latest inventory slip reflecting the correction result to the printer 42 (step A14). With this processing, the user can obtain the latest inventory slip from the output result of the printer 42.

Such a general application service assumes that the user can use the PC 41, the printer 42, and the image reader 43 in the vicinity. In the example shown in FIG. 1, the PC 41, the printer 42, and the image reader 43 are connected to the server 1 through the wired LAN 40 in the office.

A case wherein the application service is provided to the user of the PDA 31 or portable PC 51 outside the office will be described next.

FIG. 8 is a flow chart showing an application service processing operation using the data exchange unit 10. The data exchange unit 10 is set next to the external interface of the application service section 20 in the server 1.

When a request is output from a terminal, the data exchange unit 10 receives the data of the terminal from the application service section 20 (step B11). When the terminal as a transmission destination is the PC 41 in the office, the data exchange unit 10 need not be used (to "not to be utilized" at step B12).

The server 1 executes normal processing described in FIG. (step B13).

When the transmission destination is the PDA 31 or portable PC 51 outside the office, a routine for executing the data exchange process by the data exchange unit 10 starts (to "to be utilized" at step B12).

The data exchange unit 10 acquires terminal attribute data of the terminal from the terminal data management section 12 (step B14) and performs the data exchange process for the data received from the application service section 20 on the basis of the terminal attribute data (steps B15 and B16). In this case, the data exchange process means processing of absorbing the terminal attribute by converting the format of certain data in correspondence with the processing capability of the terminal.

For example, when image data (image) is to be transmitted to a terminal without image processing capability, the image data is converted into symbol data and sent. With this processing, the terminal can receive the same service as that for the remaining terminals although the data format is different. After the data exchange process corresponding to the terminal attribute is performed, the data exchange unit 10 sends the converted data to the terminal as service data (step B17).

The operation of reading the terminal attribute from the terminal data management section 12 will be described below. The terminal attribute includes a screen size, screen control data, and data type which can be displayed on the screen.

Two techniques are available to read the terminal attribute.

(A) The terminal attribute table is prepared in the terminal data management section 12.

(B) The terminal attribute data is acquired from the terminal.

In this embodiment, the former technique (A) is used when the terminal is the PDA 31. The latter technique (B) is used when the terminal is the portable PC 51. Selection of the technique (A) or (B) is determined by the terminal at tribute data management section 123 upon obtaining the correspondence among the user name, the terminal address, and the communication infrastructure from the user data table management section 142 in the user data management section 14. When the terminal side has a sufficient CPU capability, and the quality of the communication line is high, the latter technique (B) is employed to negotiate with the terminal side for the terminal attribute.

For the technique (B), a protocol for determining the terminal attribute is defined between the terminal and the server (data exchange unit 10). FIG. 9 shows the concept of the protocol sequence. As shown in this protocol sequence, the terminal and the server (data exchange unit 10) confirm the control code system (the line feed code, the tab, and the like), the bitmap, the screen size, the usable font type (including the corresponding language), and the like.

The data exchange method will be described next. The data exchange process is executed when the terminal side has no display capability, or the communication infrastructure has no sufficient data transmission capability, and the server must quantitatively/qualitatively change the data.

More specifically, the data exchange process includes the following process operations.

Conversion from binary data to text data

Conversion from image data to symbol data

Conversion from icon data to symbol data

Conversion from speech data to text data

Conversion from a color image to a monochromatic image

Conversion from binary data to text data will be described. In a document forming application, i.e., word processor software used in a PC or the like, prepared document data is often stored as binary data. This is because not only the text data but also various accessory data including the document format and the font must be stored.

Generally, the size of the binary data is larger than that of simple text data. To display the binary data, not only the text display capability but also various image display capabilities are required on the terminal side. In addition, the screen size of the terminal is often designed to be small in consideration of the portability. For this reason, the document data on the server side must be processed first and displayed in many cases.

To solve this problem, the data exchange process is effectively performed. That is, the binary data is converted into text data and sent to the terminal. With this processing, the terminal can perform processing corresponding to its processing capability. The data exchange process operation at this time is shown in FIG. 10.

FIG. 10 is a flow chart showing the data exchange process operation corresponding to the terminal attribute. Word-processor software will be exemplified as the application service. The intra server user data management section 114 in the data exchange unit 10 retrieves document data and checks the format of the stored document data (step C11).

If the document data is binary data (Yes in step C12), the data exchange executing section 113 in the data exchange unit 10 dissolves the binary document data into components such as a text, a format, and a font (step C13). Necessary data is retrieved and extracted from the components (steps C14 and C15), thereby reprocessing the data to a data format corresponding to the terminal screen (step C16). The reprocessed data, i.e., the word processor software service data which has undergone the data exchange process is provided to the terminal through the communication interface 116 for outside of data exchange unit.

This also applies to the remaining data exchange process operations. For example, when the terminal has no image processing capability, an image data portion is converted into symbol data, or an icon is converted into symbol data. When the terminal has no speech processing capability, speech data is converted into text data. With this processing, the service can be provided in correspondence with the processing capability of the terminal.

As described above, when a plurality of terminals are present on the network, service data provided as an application service is converted into a format corresponding to the processing capability of each terminal. With this processing, a terminal (e.g., a PDA) which is excellent in portability but poor in data processing capability (arithmetic capability) or screen display/user interface providing capability relative to other terminals (e.g., PCs) can be used to constitute a distributed network computing system. The terminal can receive the same service as that for the remaining terminals although the data format is different.

Such a data exchange process may be executed in accordance with the operation method of each terminal independently of the processing capability of the terminal itself.

More specifically, when the user utilizes the application service, the method of operating the application service changes depending on the terminal, e.g., an icon or a button is operated, or a command is input on the terminal. When the operation method of each terminal is registered in the user interface data management section 13 in advance as user interface data, and the data exchange process is performed in units of terminals on the basis of the user interface data, the service can always be provided in correspondence with the operation method of each terminal.

Alternatively, the data exchange process may be executed in accordance with the preference of the terminal user. In use of the application service, the preference for the display position changes depending on the user. For example, a graph is moved to the central position, or a text is displayed at the original position. When such preference for screen display (screen display preference data) is registered in the user data management section 14 in advance as user data, and the data exchange process is performed in units of users on the basis of the user data, the service can always be provided in correspondence with the display position of the user's preference.

A data exchange process corresponding to a communication infrastructure will be described next. The data exchange unit 10 grasps data associated with the communication infrastructure used by the terminal user through the communication infrastructure feature management section 152 in the communication infrastructure data management section 15 or the user data table management section 142 in the user data management section 14. Data retransmission processing control is also performed on the basis of this data. The data exchange process operation at this time is shown in FIG. 11.

FIG. 11 is a flow chart showing the data exchange process operation corresponding to the communication infrastructure. When the user uses the portable PC 51, the CPU capability of the terminal can be determined as high (No in step D11). If the data transmission capability of the communication infrastructure is high (No in step D16), the data exchange process section 11 in the data exchange unit 10 compresses/enciphers data using the compression/enciphering processing section 115 as needed and transmits the data (step D17). If the data transmission capability (transmission speed, line quality (transmission error), etc.) of the communication infrastructure is low (Yes in step D16), the data exchange process is performed to convert binary data into text data, convert format data such as centering into a blank character, or ignore format data. With this processing, the transmission data size is changed, and thereafter, the data is transmitted (step D18).

When the PDA 31 with a low CPU capability is used (Yes in step D11), the data exchange process is performed independently of the communication infrastructure, as in FIG. 10 (steps D12 to D15).

As described above, the processing capability of the terminal is checked first. If the capability is high, the communication capability of the communication infrastructure is checked, and the data exchange process corresponding to the communication capability is performed. On the other hand, assume that the terminal has a low processing capability. In this case, even when the communication infrastructure has a high communication capability, the terminal itself cannot cope with the transmitted data. Therefore, the data exchange process corresponding to the processing capability of the terminal is performed.

With this processing, even in a system having various communication infrastructures, the relative difference in data transmission rate/volume/quality among the communication infrastructures can be absorbed. Therefore, the terminal can receive the same service as that for the remaining terminals although the data format changes.

Meantime, in embodiments of this patent, the explanation has been made assuming that PCs, portable PCs, portable terminal equipment, pagers, facsimile equipment, portable personal telephones, printers etc. are used as terminal equipment, any other type servers that can be connected to the network are acceptable. Furthermore, in the data exchange method mentioned in the above, programming data which describe the processing means may be stored in the memory, which is actuated in the server 1.

The above-described data exchange process can be realized using a recording medium on which program data describing the processing method is recorded. More specifically, the method described in the above embodiment can be written in a recording medium such as a magnetic disk (e.g., a floppy disk or a hard disk), an optical disk (e.g., a CD-ROM or a DVD), or a semiconductor memory as a program which can be executed by the computer, and applied to various apparatuses, or transmitted through a communication medium and applied to various apparatuses. The computer (server 1) for realizing this apparatus loads the program recorded on the recording medium and is operation-controlled by the program, thereby executing the above-described processing.

Data enciphering processing will be described below. In use of the application service outside the office, enciphering of data is important to ensure the security of the application service. In this case, the terminal must have a capability of deciphering, so the enciphered data cannot be transmitted to all terminals. In addition, since enciphering increases the data volume, the communication infrastructure must have a high data transmission capability. The processing operation at this time is shown in FIG. 12.

FIG. 12 is a flow chart showing the data enciphering processing operation. In providing an application service of various application software by the application service section 20, the data exchange unit 10 obtains the attribute data of a terminal as a communication partner from the terminal data management section 12 (step E11), and determines the processing capability of the terminal on the basis of the attribute data (step E12).

If it is determined that the terminal has a high processing capability and a capability of deciphering enciphered data (Yes in step E12), the data exchange unit 10 obtains, from the communication infrastructure data management section 15, data of the communication infrastructure to which the terminal is connected (step E13), and determines the communication capability on the basis of the communication infrastructure data (step E14). If the communication capability is high (Yes in step E14), the data exchange unit 10 enciphers the application service data by the data exchange process section 11 (step E15), and transmits the enciphered service data to the terminal (step E16). The terminal deciphers the enciphered data and then uses the service.

If the terminal has a low processing capability and no capability of deciphering the enciphered data (No instep E12), the data exchange unit 10 directly transmits the application service data (step E16) without enciphering the data (step E17). At this time, the user may be informed of a message representing that no enciphering is performed. Alternatively, if the terminal has no capability of deciphering the enciphered data (No in step E12), the terminal side may be requested to determine whether transmission is enabled before data transmission, and transmission processing may be performed in accordance with the response.

If the terminal has a high processing capability, and the communication network connected to the terminal has a low communication capability (No in step E14), the data exchange unit 10 directly transmits the application service data (step E16) without enciphering the data (step E17). If the communication network has a low communication capability (No in step E14), the terminal side may be requested to determine whether transmission is enabled before data transmission, and transmission processing may be performed in accordance with the response.

Meantime, regarding the enciphering process, the option for the enciphering may be left to the user, even if the terminal equipment is of high level capable to process cipher code.

There are various levels of data enciphering ranging from simple scrambling to advanced enciphering processing. The load on the terminal or communication infrastructure also changes depending on the enciphering level. The level of enciphering can be appropriately changed in correspondence with the processing capability of the terminal or the communication capability of the communication infrastructure.

With the data enciphering function, the security of the application service can be ensured even outside the office. In this case, enciphering can be appropriately performed by determining the type of available enciphering or the enciphered data volume which can be transmitted by the communication infrastructure in use on the basis of the terminal attribute or communication infrastructure attribute.

Data compression processing will be described next. Data compression is effective in transmission of data in a large quantity, e.g., image data. In this case, a capability of expanding compressed data is required on the terminal side, as in the above-described data enciphering processing. The communication capability of the communication infrastructure need not be considered because compressed data can be transmitted although it takes a long time. The processing operation at this time is shown in FIG. 13.

FIG. 13 is a flow chart showing the data compression processing operation. In providing the application service by the application service section 20, the data exchange unit 10 obtains the attribute data of a terminal as a communication partner from the terminal data management section 12 (step F11), and determines the processing capability of the terminal on the basis of the attribute data (step F12).

If it is determined that the terminal has a high processing capability and a capability of expanding the compressed data (Yes in step F12), the data exchange unit 10 compresses the application service data by the data exchange process section 11 (step F13), and transmits the compressed service data to the terminal (step F14). The terminal expands the compressed data and then uses the service.

If the terminal has a low processing capability and no capability of expanding the compressed data (No in step F12), the data exchange unit 10 directly transmits the application service data (step F14) without compressing the data (step F15). At this time, the user may be informed of a message representing that no compression is performed.

With the data compression function, data transmission can be efficiently performed. In this case, compression can be appropriately performed by determining the type of available data compression on the basis of the terminal attribute.

In the example shown in FIG. 13, it is determined whether data compression is enabled only on the basis of the processing capability of the terminal. However, whether data compression is enabled may be determined on the basis of not only the processing capability of the terminal but also the communication capability of the communication network connected to the terminal.

The level of compression can be appropriately changed in correspondence with the processing capability of the terminal or the communication capability of the communication infrastructure.

Utilization of the application service using an I/O unit will be described next. I/O units mean units other than a computer and correspond to the handy phone 32, the pager 33, the FAX 34, the printer 42, and the image reader 43 in the example shown in FIG. 1.

FIG. 14 is a flow chart showing a processing operation in utilization of the application service using an I/O unit. Upon receiving a signal representing utilization of the application service from the user (step G11), the data exchange unit 10 certifies the user through the user data management section 14 (step G12), and determines the type of unit of the user (step G13).

If the user is using an I/O unit (Yes in step G13), the data exchange unit 10 performs the data exchange process corresponding to the I/O unit (step G14), and transmits the converted service data (step G15).

More specifically, when the I/O unit is the handy phone 32, the data exchange unit 10 converts, e.g., text data into speech data using the speech processing function, and provides the service as a voice message.

For the pager 33, text data is converted into message data corresponding to a predetermined number of characters and transmitted. For the FAX 34, text data is converted into image data and transmitted. In this way, the service is provided within the specific limitation corresponding to each I/O unit.

If the unit of the user is not an I/O unit but a terminal having a CPU capability (No in step G13), the data exchange unit 10 executes a normal application service (step G16). That is, the data exchange unit 10 performs the data exchange process corresponding to the processing capability of each terminal and provides the service.

With the data exchange process corresponding to the I/O unit, even when the user uses a FAX or the like, the application service can be provided in correspondence with the FAX.

The service data from the server can also be subjected to the data exchange process corresponding to both the attribute of the I/O unit and the attribute of the communication infrastructure.

The method described in the above embodiment can be written in a recording medium such as a magnetic disk (e.g., a floppy disk or a hard disk), an optical disk (e.g., a CD-ROM or a DVD), or a semiconductor memory as a program which can be executed by the computer, and applied to various apparatuses, or transmitted through a communication medium and applied to various apparatuses. The computer (server 1) for realizing this apparatus loads the program recorded on the recording medium and is operation-controlled by the program, thereby executing the above-described processing.

Hereinafter, the cases, wherein data service as application service by means of a structured language such as HTML (Hyper text markup language) and SGML(Standard generalized mark up language) is described, will be explained. For the reference, HTML is a structured language that is used for WWW (world wide web) that has come to wide use. SGML is a structured language, which is expected to be brought to wide use in future in parallel with the spread of CALS (continuous acquisition and lifecycle support).

Generally speaking, as one of the management methods of document data including multimedia data, a method by means of structured language is contemplated. In this case, each component, which comprising document data such as text data, image data, animation data, program is managed by tag and reading device (browser) is to indicate document data on the screen based on the tag. Accordingly, when the service data described by means of tag language is presented, one can know, what kind of part is provided by documentation data presented as service data, if one analyzes the tag on the side of server.

Therefore, before actually processing the data transmission, the structured document is analyzed based on tag data and the attribute of respective parts such as data size, additional data (data which cannot be indicated by tag data only) will be grasped, and data exchange device will be installed in the server for grasping the type corresponding to the attribute of terminal equipment and communication infrastructure. In this case, the tags for data exchange are inserted into the structured document produced from the data exchange device.

Such being the case, by managing the data by means of structured document, the management of the data becomes easy and also the analysis of the document parts becomes easy at the data exchange operation. If the data exchange system is constructed based on the regulation for the structured language, which is wide spread such as HTML, the change of the system to the wide spread WWW system and its influence can be minimized.

FIG. 15 is a view showing the concept of an entire system including an application service on the assumption of a structured document. Referring to FIG. 15, reference numeral 61 denotes a structured document management section for managing service data provided as an application service of various application software in a structured document format. The structured document management section 61 is arranged in an application service section 20 shown in FIG. 1. In this embodiment, the application service section 20 manages service data which has been described in the structured document format in advance. However, the service data may be described in a non structured document format (FIG. 20).

Reference numeral 162 denotes a data exchange section for performing the data exchange process corresponding to a terminal attribute or a communication infrastructure attribute. The data exchange section 162 corresponds to a data exchange unit 10 shown in FIG. 1. Reference numeral 163 denotes a network section corresponding to various communication networks for connecting the server and terminals. The network section 163 corresponds to the public network 30, the wired LAN 40, and the wireless LAN 50 shown in FIG. 1. Reference numerals 64a to 64c denote terminals which receive the service from the server and correspond to, e.g., a PC (Personal Computer), an NC (Network Computer), or a PDA (Personal Digital Assistants). The terminals 64a to 64c are connected to different communication infrastructures and have different processing capabilities. The terminals 64a to 164c correspond to the PDA 31, the PC 41, or the portable PC 51 shown in FIG. 1.

With this structure, the application services of various application software are managed in the structured document format (e.g., an HTML document) by the structured document management section 61. FIG. 16 shows an example of the structured document for displaying a display as shown in FIG. 21.

Referring to FIG. 16, a tag 66 indicates that text data follows. A tag 67 represents document format data, and in this case, defines centering. A tag 68 represents font data, and in this case, defines a large font. A tag 69 indicates image data (a file name of a file in which image data is stored).

The data exchange section 162 analyzes this structured document and checks the types and data sizes of components constituting the document on the basis of the tag data inserted into the document. In transmitting each component data, the data exchange section 162 checks the processing capability of the terminal or the communication capability of the communication infrastructure and performs the data exchange process in correspondence with the capability.

If it is determined that the data transmission capability of the communication infrastructure is low, the transmission data volume is reduced by performing the data exchange process (or data compression) for a document component in a large data volume. If it is determined on the basis of the terminal attribute that the terminal as a communication partner has no document display capability (for a terminal without any browser), the data is converted into a format that the terminal can be displayed and transmitted.

In the data exchange process, the data is converted such that the document is displayed in correspondence with the user's preference (data exchange process based on user data).

The processing operation will be described next in detail.

An operation performed when service data in the structured document format is managed by the application service section 20 will be described below. An operation performed when the application service section 20 manages service data in the non-structured document format will be described later with reference to FIG. 20. Processing corresponding to the terminal attribute will be described first.

FIG. 17 is a flow chart showing a processing operation corresponding to a terminal attribute in use of the structured document. In FIG. 1, the application service section 20 in the server 1 manages service data described in a structured document format. When a doc