Method and apparatus for providing a flexible and scalable context service

• US 20030018692A1
• Filed: 07/18/2002
• Published: 01/23/2003
• Est. Priority Date: 07/18/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lei, Hui, Hunt, Guerney Douglass Holloway, Ebling, Maria Rene
• Granted Patent: US 6,970,947 B2
• Time in Patent Office: Days
• US Class Current: 718/108
• CPC Class Codes: G06F 2209/544 Remote
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

A flexible and extensible context server for collecting, maintaining, and disseminating context information is disclosed. The context server receives requests from requesters for context information via a secure context server interface (SCS API). Communication between the requesters and the context server is conducted by means of predetermined forms. The requests received at the SCS API are passed to a mediator, which collects data from various context drivers. Each context driver is coupled to the mediator, and collects predetermined type of context information from at least one context information source. The mediator determines the appropriate context driver which can handle the request, based on its type. Operation of the context server is also controlled by a set of context utilities, including a context cache for storing recently obtained context information, a privacy engine for storing privacy preferences and an event engine for event handling.

Claims

1. A system for handling context information, comprising:

(a) an interface for receiving a request for context information;

(b) a mediator, coupled to receive the request from the interface, for determining which one of a plurality of context drivers to route the request to; and

(c) said plurality of context drivers, each coupled to the mediator, each context driver adapted to receive the request from the mediator and collect a predetermined type of context information.

2. The system of claim 1, further comprising:

at least one context information source, from which said each context driver is adapted to collect said predetermined type of context information.

3. The system of claim 1, further comprising:

a privacy engine coupled to at least one context driver, the privacy engine storing privacy preferences for each type of context information, and including means for denying or granting the request based upon the stored privacy preferences.

4. The system of claim 3, wherein the request is represented by a form which includes a plurality of fields, and the privacy preferences can be specified for each field in the form.

5. The system of claim 1, further comprising:

a context cache coupled to at least one context driver, the context cache storing the context information recently retrieved from the context information source.

6. The system of claim 1, further comprising:

an event engine coupled to at least one context driver, for determining if there is the context information which satisfies the request.

7. The system of claim 6, wherein the event engine receives the request as an event subscription and attempts to match the event subscription against the context information if a context event of an arrival of the context information occurs.

8. The system of claim 7, wherein the event engine, if a match of the event subscription occurs, sends a notification to the context driver.

9. The system of claim 1, wherein the request is represented by a form, a type of which is predefined based on a type of the context information.

10. The system of claim 9, wherein each form includes a plurality of fields, and the interface receives the form at least one field of which is filled out as the request.

11. The system of claim 9, wherein the mediator determines the context drivers based on the type of the form.

12. The system of claim 9, wherein the system can be modified to handle additional types of context information by generating a new form corresponding to these additional types.

13. The system of claim 9, wherein said each context driver generates a response conforming to a format of the form.

14. The system of claim 1, wherein said each context driver collects the predetermined type of context information, in response to receiving the information request from the mediator.

15. The system of claim 1, wherein said each context driver collects the predetermined type of context information, independently of operations of the interface and the mediator.

16. The system of claim 1, further comprising:

a work pacer coupled to at least one context driver, the work pacer scheduling a timing of collecting the predetermined type of context information.

17. The system of claim 1, wherein the system can be scaled by registering types of the context information the system handles in a registry that can be referred to by another computer system.

19. The method of claim 18, wherein said receiving step receives the request by means of a first form, contents of which are filled by the requester.

20. The method of claim 19, wherein said returning step returns the response in a second form confirming to a format of the first form.

21. The method of claim 18, further comprising the step of:

checking, after the receiving step, authorization of the requester to receive the information.

18. A method for handling context information, comprising the steps of:

receiving a request for the context information, said request including an identification and indicating information desired by a requester;

directing, based on the identification, the request to at least one of a plurality of context drivers, each of which is adapted to collect a predetermined type of context information; and

returning a response including desired information