Method and apparatus for reliable unidirectional communication in a data network

• US 6,954,893 B2
• Filed: 08/15/2001
• Issued: 10/11/2005
• Est. Priority Date: 08/15/2000
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Mehravari, Nader, Madden, Patrick H., Ternullo, Noah J.
• Primary Examiner(s): LAMARRE, GUY J
• Application Number:
  US09/930,004
• Publication Number:
  US 20020023249A1
• Time in Patent Office: 1,518 Days
• Field of Search: 370/252, 712/226, 714799-824, 709/218, 709/219, 345/733, 725/48, 725/53, 725/59
• US Class Current: 714/807
• CPC Class Codes: G06F 11/10 Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
• CPC Class Codes: G06Q 30/02 Marketing; Price estimation or determination; Fundraising
• CPC Class Codes: H04B 10/11 Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
• CPC Class Codes: H04B 10/114 Indoor or close-range type systems
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information
• CPC Class Codes: H04B 10/2569 due to polarisation mode dispersion [PMD]
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 67/30 Profiles
• CPC Class Codes: H04L 67/306 User profiles
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04L 67/55 Push-based network services
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/565 Conversion or adaptation of application format or content adding application control or application functional data H04L67/561
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 67/5681 Pre-fetching or pre-delivering data based on network characteristics
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 76/40 for selective distribution or broadcast

Abstract

A system and method for performing reliable unidirectional communication in a data network is disclosed. Unidirectional data is sent from a transmitting device to a receiving device. Prior to transmission, the data is divided into a window (401b) comprised of data bytes. A checksum value (407) is computed across data bytes comprising window (401b). Checksum value (407) is placed into an XML integrity element (404) that encapsulates window (401b) in a manner allowing a receiving device to use the contents of integrity element (404) to validate the received window (401b). Checksum value (407) is compared to a second check sum value computed across window (401b) at the receiving device. If checksum value (407) matches the second checksum value, window (401b) is validated.

Claims

1. A computer-readable data signal for modifying the operation of a receiving device, said data signal comprising:

at least one frame for modifying the operation of the receiving device when the receiving device receives and processes said at least one frame; and

an integrity element associated with said at least one frame, said integrity element containing a first checksum value determined from said at least one frame, said first checksum for validating the contents of said at least one frame, said validating being successful if a second checksum value computed over said at least one frame at said receiving device matches said first checksum value.

2. The computer-readable data signal of claim 1, wherein said at least one frame includes

contextually relevant content,

said computer-readable data signal is transmitted using a unidirectional protocol to said receiving device, said receiving device having a current context,

said receiving device is for accepting or ignoring said at least one frame based on said contextually-relevant content and said current context.

3. The computer-readable data signal of claim 1 further comprising:

at least one eXtensible markup language (XML) element.

4. The computer-readable data signal of claim 1 wherein said computer-readable data signal is transmitted as a diffuse infrared signal.

5. The computer-readable data signal of claim 1 wherein said

at least one frame and said integrity element are composed of a plurality of bytes, said integrity element containing at least one parsable data structure.

6. The computer-readable data signal of claim 5 wherein said

integrity element is detected by said receiving device, said integrity element encapsulating said plurality of bytes.

7. The computer-readable data signal of claim 1 wherein said computer-readable data signal is created by modulating an electric light.

8. The computer-readable data signal of claim 1 wherein said receiving device is a handheld device having a current context.

9. The computer-readable data signal of claim 8 wherein the computer-readable data signal is transmitted to a diffuse infrared transmitter for transmission to the handheld device.

10. The computer-readable data signal of claim 1 wherein said

at least one frame is passed to a receiving module if said first checksum value matches said second checksum value.

11. The computer-readable data signal of claim 1 wherein said

at least one frame is discarded if said first checksum value does not match said second checksum value.

12. The computer-readable data signal of claim 1 wherein said at least one frame includes

service data from at least one service provider, said

service data being filtered to create contextually relevant information, said

contextually relevant information being formatted according to a pre-selected data structure language, said

formatted contextually relevant information being grouped into said at least one frame, said

at least one frame being parsed at said receiving device using said pre-selected data structure language to retrieve said contextually relevant information.

13. The computer-readable data signal of claim 1 wherein said integrity element further comprises:

a frame size value, said frame size value corresponding to the number of bytes in said at least one frame that were used in computing said first checksum value;

a seed value, said seed value being used in determining said first checksum value; and

an operator used in conjunction with said seed value to compute said first checksum value.

14. The computer-readable data signal of claim 13 wherein said validating comprises:

means for computing said second checksum value based on said seed value, said operator, said frame size value, and said at least one frame.

15. The computer-readable data signal of claim 13 wherein said operator identifies a mathematical operator.

16. The computer-readable data signal of claim 1 wherein said contents of said at least one frame include at least one eXtensible markup language (XML) element.

17. The computer-readable data signal of claim 1 wherein said contents of said at least one frame include at least one parsable data structure.

18. A computer-readable data signal for modifying the operation of a receiving device, said data signal comprising:

a frame containing at least a subset of a plurality of bytes, the contents of said frame for modifying said operation of said receiving device upon receipt and processing, by said receiving device; and

an integrity element containing a first checksum value determined from said at least a subset of said plurality of bytes, said first checksum for validating the contents of said frame, said validating being successful if a second checksum value computed over said frame at said receiving device matches said first checksum value,

wherein said integrity element is an eXtensible markup language (XML) element encapsulating said frame.

19. The computer-readable data signal of claim 18 wherein said integrity element further comprises:

a frame size value, said frame size value corresponding to the number of bytes in said frame that were used in computing said first checksum value;

a seed value, said seed value being used in determining said first checksum value; and

an operator used in conjunction with said seed value to compute said first checksum value.

20. The computer-readable data signal of claim 18 wherein said contents of said frame include an eXtensible markup language (XML) element.

21. The computer-readable data signal of claim 18 wherein said contents of said frame include at least one parsable data structure.