Real-time information transmission system

• US 6,480,883 B1
• Filed: 06/29/1999
• Issued: 11/12/2002
• Est. Priority Date: 06/30/1998
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tsutsumitake, Hideyuki
• Primary Examiner(s): Lim, Krisna
• Application Number:
  US09/342,732
• Time in Patent Office: 1,232 Days
• Field of Search: 709/203, 709/217, 709/218, 709/219, 709/232
• US Class Current: 709/203
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/025 for remote control or remote monitoring of applications
• CPC Class Codes: H04L 67/55 Push-based network services
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A real-time information transmission system can immediately transmit information updated on a server to a client, even if directly communication between the server and the client is not established. If the server receives a page request from the client, the server returns a requested page to the client. The same connection ID is added to the request from the client and to an associated response from the server. The client analyzes the page. If an event request is included in the analyzed page, the client adds another connection ID to the request and sends it to the server. Using the connection ID, the server sends an event to the client each time the event has occurred. The client processes the event and reflects the processed result on a screen of a display.

Claims

1. A real-time information transmission system for transmitting information in real time from a server to a client, the system comprising:

determination means for determining, on the basis of an information transmission request from the client to the server, whether the request is a page request or an event request;

page transmission means for transmitting, if the determination means has determined that the request is the page request, information of the requested page only once from the server to the client at an originating point of the page request;

event generating means for generating events; and

event transmission means for transmitting, when the determination means has determined that the request is the event request, those of the events generated by the event generating means which are associated with the event request, from the server to the client at an originating point of the information transmission request in response to the event request issued once.

2. The system according to claim 1, wherein connection between the client and the server is maintained while the event request is efficient.

3. The system according to claim 1, wherein the server transmits, in response to the page request from the client, page information in which at least one event request information unit is set for issuing the event request from the client at the originating point of the page request to the server to request updated information of the page information, and

when the event request has been sent from the client to the server in accordance with the page information in which the event request information unit is set, an event notification for reflecting an updated content of the page information is transmitted from the server at a destination point of the event request to the client at the originating point of the event request, each time an event associated with update of the page information has occurred.

4. The system according to claim 1, wherein in a situation in which an event notification needs to be sent from the server to the client at an originating point of the event request each time an event has occurred in response to the event request from the client, the server monitors occurrence of the event in the server,

where no event has occurred in a predetermined time period, a client state confirmation event notification is sent from the server to the client to confirm the state of the client at the originating point of the event request, and

when the even notification has been sent from the server, the server confirms whether the even notification has been successful, and if the event notification has failed, a network connection used for the event notification is cut off on the server side.

5. The system according to claim 1, wherein a predetermined procedure to be executed by the client is set in page information in which information on the event request is set, which page information is transmitted from the server in accordance with the page request from the client,

whereby when the client, which has received the page information in which the event request is set, changes display of the page information to display of page information corresponding to another page request, the client cuts off network connection associated with an event notification from the server in response to the event request, according to the predetermined procedure.

6. The system according to claim 1, wherein information indicating whether occurrence of an associated event is periodic or non-periodic, information on a time interval if the occurrence of the event is periodic and a predetermined procedure to be executed by the client are set in page information in which information on the event request is set, which page information is transmitted from the server in accordance with the page request from the client,

whereby when the occurrence of the associated event is periodic and the time interval thereof is greater than a predetermined time, the client which has received the page information, in which the event request information is set, temporarily cuts off network connection each time the client receives an event notification from the server in response to the event request, according to the predetermined procedure in the page information, and also the client executes an operation to issue the event request once again after an event generation scheduled time set by the time interval has arrived.

7. The system according to claim 1, wherein a predetermined procedure to be executed by the client is set in page information in which the event request information is set, which page information is sent from the server in response to the page request from the client, or in an event notification transmitted from the server in response to the event request from the client, and time information on occurrence of the same event occurs is set in the event notification,

whereby the client, which has received the event notification, is caused to monitor the arrival of the next event notification according to the predetermined procedure, and to issue the event request to the server where the client could not receive the next event notification from the server at a set time indicated in the time information in the received event notification.

8. The system according to claim 1, wherein a procedure for adding time information for issuing a next event request to the event request issued by the client is set in page information in which the event request information is set, which page information is sent from the server in response to the page request from the client,

whereby when the event request has been issued from the client to the server, the server monitors arrival of the next event request from the client, and cuts off network connection relating to the event request, if the server could not receive the next event request at a set time indicated in the time information in the preceding event request.

9. The system according to claim 1, wherein information on an exclusive page, which is prohibited from being displayed simultaneously on a plurality of clients, is registered in the server,

where the server has received the page request from the client, the server determines whether the requested page is an exclusive page, on the basis of the registered information of the exclusive page,

if the request page is the exclusive page, the server determines whether the page is being displayed on another client,

if the page is not being displayed on said another client, new page information, in which the event request information is set in the requested page information, is sent to the client at the originating point of the page request,

if the page is being displayed on said another client, specific page information, in which specific event request information for issuing a specific event request is set, is sent to the client at the originating point of the page request, instead of the requested page information, and the client is caused to wait for display of the requested page information, and

where network connection relating to an event notification from the server to the client which is in the state of displaying the exclusive page is cut off and there are clients which are in the state of waiting for display of the exclusive page, new page information, in which the event request information is set in the requested page information, is sent to one of the clients waiting for the display of the exclusive page as a response to the specific event request.

10. The system according to claim 9, wherein where the page request or the event request has been sent to the server from the client which is in the waiting state, processing of the request in the server is changed from normal state.

11. An information providing server for transmitting page information requested by a page request from an information display client to the client via a network, the server comprising:

request determination means for determining, when a request for information provision has been sent from the client, whether the request is a page request for requesting new page information or an event request for requesting updated information;

page information transmission means for transmitting, when the request is the page request, requested page information only once from the server to the client at an originating point of the page request; and

event transmission means for transmitting, when the request is the event request, an event notification for updating associated page information each time an event corresponding to the associated page information has occurred.

12. A real-time information transmission system comprising:

a control device;

a server connected to the control device, the server including,

page request receiving means for receiving a page request,

page transmission means for transmitting a page requested to the page request receiving means,

event request receiving means for receiving an event request,

event generating means for generating an event representing at least a state of the control device,

connection management means for managing kinds of events requested to the event request receiving means and managing connection with an originating point of the event request, and

event transmission means for transmitting a plurality of events generated successively from the event generating means to the originating point of the event request, while the connection with the originating point of the event request is maintained; and

a client connected to the server via a network, the client including,

page request means for requesting a page to the server,

page receiving means for receiving a page sent from the server,

event request means for requesting an event to the server,

event receiving means for receiving a plurality of events from the server in response to a single event request from the event request means, and

display means for displaying the page received by the page receiving means and displaying information based on the event received by the event receiving means.