Communication apparatus and communication method using dummy data

• US 6,094,212 A
• Filed: 01/08/1997
• Issued: 07/25/2000
• Est. Priority Date: 01/10/1996
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Imaeda, Eiji
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): DESIR, JEAN WICEL
• Application Number:
  US08/781,492
• Time in Patent Office: 1,294 Days
• Field of Search: 348/15, 348/17, 348/14, 348/13, 348/12, 348/464, 348/500, 370/264, 370/260, 370/503, 370/504, 370/505, 375/356, 379/88.13
• US Class Current: 348/14.12
• CPC Class Codes: H04N 7/148 Interfacing a video terminal to a particular transmission medium, e.g. ISDN
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04Q 11/0471 Terminal access circuits

Abstract

This invention proposes to eliminate the limitation that the reception data, assigned to a subchannel, cannot be re-assigned to another subchannel in the transmission. For this purpose, in a configuration of the present invention, the transmission information, formed by multiplexing information of plural kinds in a multiplexing unit, is transmitted to a line control unit which is connected to a communication line and serves to transmit and receive information to and from different locations, while the reception information received from the communication line is received by the line control unit and separated in a demultiplexing unit into the information of respective kinds, and at least one is selected by an entire control unit from thus separated plural information and is turned back to the multiplexing unit through a turn-back bus.

Claims

1. A communication apparatus for effecting communication by communication data, at least containing image data and a signal relating to the synchronization of communication, among plural locations under predetermined formatting, said apparatus comprising:

reception means for receiving said communication data;

extraction means for extracting said signal relating to the synchronization from said received communication data;

process means for processing said image data according to said extracted signal; and

transmission means for effecting transmission by adding image data generated in the present apparatus to said received communication data and effecting said predetermined formatting,

wherein said received communication data has been divided to a plurality of subchannels each having same data amount, a part extracted from said signal relating to the synchronization is replaced with dummy data when data of subchannel which included said signal relating to the synchronization extracted from said extraction means among said subchannels is turned back to the other subchannel.

2. A communication apparatus according to claim 1, wherein plural units thereof positioned in plural locations are arranged in a ring shape through communication lines.

3. A communication apparatus according to claim 1, wherein said communication data include audio data and control data.

4. A communication apparatus according to claim 1, wherein said transmission means is adapted, at said predetermined formatting, to add a signal relating to the synchronization of the communication between the present apparatus and a destination apparatus.

5. A communication apparatus according to claim 1, wherein the image data contained in said communication data are encoded, and said process means at least includes decoding means for said encoded image data.

6. A communication apparatus according to claim 1, wherein said transmission means is adapted to effect predetermined formatting of said received communication data without decoding thereof, together with image data generated and encoded in the present apparatus.

7. A communication apparatus according to claim 1, wherein said predetermined format is a format recommended by the ITU-TS recommendation H.221.

8. A communication apparatus according to claim 1, wherein said signal relating to the synchronization is an FAW signal defined in the ITU-TS recommendation H.221.

9. A communication apparatus according to claim 4, wherein said predetermined format is a format recommended by the ITU-TS recommendation H.221.

10. A communication apparatus according to claim 4, wherein said signal relating to the synchronization is an FAW signal defined in the ITU-TS recommendation H.221.

11. A communication apparatus according to claim 6, wherein said predetermined format is a format recommended by the ITU-TS recommendation H.221.

12. A communication apparatus according to claim 6, wherein said signal relating to the synchronization is an FAW signal defined in the ITU-TS recommendation H.221.

13. A communication apparatus according to claim 7, wherein said signal relating to the synchronization is an FAW signal defined in the ITU-TS recommendation H.221.

14. A communication method for effecting communication by communication data, at least containing image data and a signal relating to the synchronization of communication, among plural locations under predetermined formatting, the method comprising steps of:

receiving said communication data;

extracting said signal relating to the synchronization from said received communication data;

processing said image data according to said extracted signal; and

effecting transmission by adding image data generated in a self apparatus to said received communication data and effecting said predetermined formatting;

wherein said received communication data has been divided to a plurality of subchannels each having same data amount, a part extracted from said signal relating to the synchronization is replaced with dummy data when data of subchannel which included said signal relating to the synchronization extracted in said extraction among said subchannels is turned back to the other subchannel.