Multipoint teleconference system employing communication channels set in ring configuration

• US 5,365,265 A
• Filed: 07/15/1992
• Issued: 11/15/1994
• Est. Priority Date: 07/15/1991
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Takizawa, Masaaki, Shibata, Yoji
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Chan, Jason
• Application Number:
  US07/913,401
• Time in Patent Office: 853 Days
• Field of Search: 379/53, 379/54, 379/201, 379/202, 379/203, 379/204, 379/205, 358/85, 348/14, 348/15, 348/16, 348/17, 348/19
• US Class Current: 348/14.1
• CPC Class Codes: G09B 5/14 with provision for individual teacher-student communication
• CPC Class Codes: H04M 3/567 Multimedia conference systems
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04Q 11/0428 Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/13337 Picturephone, videotelephony

Abstract

A multipoint teleconference system dispensing with an MCU, in which terminals are connected into a loop configuration through an ISDN in such a way that each terminal is coupled with each of the adjacent terminals by a single B channel. Thus, a communication frame is revolved through a looped communication channel. Each terminal renews video data which is contained in an allotted area within the received communication frame and which was transmitted by the terminal itself, and it relays the resulting communication frame to the next terminal.

Claims

1. In a multipoint video telephone/teleconference system having a plurality of video telephone/teleconference terminals which are connected to digital communication channels and which transmit and receive communication frame containing video telephonic/teleconferential data, which includes video data, through the connected digital communication channels, said multipoint teleconference system comprising:

wherein said digital communication channels connect said plurality of video telephone/teleconference terminals in a ring configuration; and

wherein each of said video telephone/teleconference terminals comprises;

generation means for generating the video telephonic/teleconferential data which is to be sent to the other video telephone/teleconference terminals, said telephonic/teleconferential data including said video data,

resumption means for resuming said video data contained in said communication frame received from the video telephone/teleconference terminal at an upper stream position of a loop with respect to transfer of said communication frame,

relay means for transmitting the received communication frame to the video telephone/teleconference terminal at a lower stream position of said loop so that said communication frame may revolve around said loop, said loop being formed of said digital communication channels which connect said plurality of video telephone/teleconference terminals to one another,

cancellation means for cancelling the video data which was entered into said communication frame by a video telephone/teleconference terminal itself and which has revolved around said loop, from within said communication frame which is to be relayed by said relay means, and

transmission means for entering the generated video data into an unused area of said communication frame which is to be relayed by said relay means, thereby sending said generated video data to said other video telephone/teleconference terminals which lie on said loop.

2. In a multipoint teleconference system having an ISDN which transfers a communication frame around a set channel, and a plurality of video telephone/teleconference terminals which conform to CCITT Recommendation H.320 and which are connected to the ISDN, said multipoint teleconference system comprising:

wherein said communication frame contains video telephonic/teleconferential data including video data;

wherein at least one of said plurality of video telephone/teleconference terminals comprises;

channel setting means for setting channels between the adjacent video telephone/teleconference terminals in said ISDN so that said plurality of video telephone/teleconference terminals may be connected in a ring configuration; and

wherein each of said video telephone/teleconference terminals comprises;

generation means for generating said video telephonic/teleconferential data which is to be sent to the other video telephone/teleconference terminals, said telephonic/teleconferential data including the video data,

resumption means for resuming said video data contained in the frame received from the video telephone/teleconference terminal at an upper stream position of a loop with respect to transfer of said communication frame,

relay means for relaying the received communication frame to the video telephone/teleconference terminal at a lower stream position of said loop so that said communication frame may revolve around said loop, said loop being formed of said plurality of video telephone/teleconference terminals and said channels set by said channel setting means so as to connect said video telephone/teleconference terminals,

cancellation means for canceling the video telephonic/teleconferential data which was entered into said communication frame by a video telephone/teleconference terminal itself and which has revolved around said loop, from within said communication frame which is to be relayed by said relay means, and

transmission means for entering the generated video data into an unused area of said communication frame which is to be relayed by said relay means, thereby transferring said generated video data to said other video telephone/teleconference terminals which lie on said loop.

3. A multipoint teleconference system as defined in claim 2, wherein:

said communication frame is a frame stipulated in CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frame"), a frame stipulated in CCITT Recommendation H. 261 (herein below, termed "H. 261 frame") is prepared in said H. 221 frame, and groups of blocks (GOB'"'"'s) included in said H. 261 frame are respectively allotted to the individual video telephone/teleconference terminals, said GOB'"'"'s each being a plurality of blocks into which the data area for H. 261 frames are divided;

said resumption means resumes said video data contained in the plurality of GOB'"'"'s of said H. 261 frame prepared in the received H. 221 frame, into a picture of one picture frame so as to present a display output;

said cancellation means cancels video data which was entered into said H. 261 frame by said transmission means of said video telephone/teleconference terminal itself and which has revolved around said loop, from at least one GOB allotted to said video telephone/teleconference terminal itself; and

said transmission means enters the generated video data into at least one GOB allotted to said video telephone/teleconference terminal itself, among said GOB'"'"'s of said H. 261 frame prepared in said H. 221 frame.

4. A multipoint teleconference system as defined in claim 3, wherein:

said plurality of GOB'"'"'s included in said H. 261 frame are divided into N (being a natural number) groups, which are respectively allotted to the N video telephone/teleconference terminals; and

said resumption means of each of said video telephone/teleconference terminals resumes the video data contained in said H. 261 frame, in respective areas of one picture frame corresponding to the GOB'"'"'s having contained said video data, so as to present said display output.

5. A multipoint teleconference system as defined in claim 2, wherein:

said communication frame is a frame stipulated in CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frame"), and a frame stipulated in CCITT Recommendation H. 261 (herein below, termed "H. 261 frame") is prepared in said H. 221 frame;

said each video telephone/teleconference terminal further comprises audio data resumption means for resuming audio data into speech so as to emit the speech;

said generation means generates the video telephonic/teleconferential data including audio data;

said cancellation means cancels an audio data component which was entered into said H. 261 frame by said transmission means of said video telephone/teleconference terminal itself and which has revolved around said loop, from audio data contained in said H. 261 frame of the received H. 221 frame;

said audio data resumption means resumes the audio data with said audio data component of said terminal itself cancelled by said cancellation means, into the speech so as to emit said speech; and

said transmission means enters new audio data into said H. 261 frame of the H. 221 frame to be relayed by said relay means, instead of said audio data contained in said H. 261 frame of said H. 221 frame received by said relay means, said new audio data being obtained in such a way that said audio data generated by said generation means is added to said audio data, with said audio data component of said terminal itself cancelled by said cancellation means.

6. In a multipoint teleconference system having an ISDN which transfers a communication frame around a set channel, and a plurality of video telephone/teleconference terminals which conform to CCITT Recommendation H.320 and which are connected to the ISDN, said multipoint teleconference system comprising;

wherein at least one of said plurality of video telephone/teleconference terminals comprises;

channel setting means for setting channels between the adjacent video telephone/teleconference terminals in the ISDN so that said plurality of video telephone/teleconference terminals may be connected in a ring configuration;

wherein each of said video telephone/teleconference terminals comprises;

generation means for generating said video telephonic/teleconferential data which is to be sent to the other video telephone/teleconference terminals,

relay means for relaying the communication frame received from the video telephone/teleconference terminal at an upper stream position of a loop to the video telephone/teleconference terminal at a lower stream position of said loop so that said communication frame may revolve around said loop, said loop being formed of said plurality of video telephone/teleconference terminals and said channels set by said channel setting means so as to connect said video telephone/teleconference terminals,

transmission means for entering the generated video telephonic/teleconferential data into said communication frame which is to be relayed by said relay means, thereby transferring said generated video telephonic/teleconferential data to said other video telephone/teleconference terminals which lie on said loop, and

cancellation means for canceling the video telephonic/teleconferential data which was entered into said communication frame by said transmission means of a video telephone/teleconference terminal itself before and which has revolved around said loop, from within said communication frame which is to be relayed by said relay means;

wherein said communication frame is a frame stipulated in CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frame"), a frame stipulated in CCITT Recommendation H. 261 (herein below, termed "H. 261 frame") is prepared in said H. 221 frame, and groups of blocks (GOB'"'"'s) included in said H. 261 frame are respectively allotted to the individual video telephone/teleconference terminals, said GOB'"'"'s each being a plurality of blocks into which the data area for H. 261 frames are divided;

wherein each of said video telephone/teleconference terminals further comprises resumption means for resuming video data contained in the plurality of GOB'"'"'s of said H. 261 frame prepared in the received H. 221 frame, into a picture of one picture frame so as to present a display output;

wherein said cancellation means cancels video data which was entered into said H. 261 frame by said transmission means of said video telephone/teleconference terminal itself and which has revolved around said loop, from at least one GOB allotted to said video telephone/teleconference terminal itself; and

wherein said transmission means enters the generated video data into at least one GOB allotted to said video telephone/teleconference terminal itself, among said GOB'"'"'s of said H. 261 frame prepared in said H. 221 frame.

7. A multipoint teleconference system as defined in claim 6, wherein:

wherein said plurality of GOB'"'"'s included in said H. 261 frame are divided into N (being a natural number) groups, which are respectively allotted to the N video telephone/teleconference terminals; and

wherein said resumption means of each of said video telephone/teleconference terminals resumes the video data contained in said H. 261 frame, in respective areas of one picture frame corresponding to the GOB'"'"'s having contained said video data, so as to present said display output.

8. In a multipoint teleconference system having an ISDN which transfers a communication frame around a set channel, and a plurality of video telephone/teleconference terminals which conform to CCITT Recommendation H.320 and which are connected to the ISDN, said multipoint teleconference system comprising:

wherein at least one of said plurality of video telephone/teleconference terminals comprises;

channel setting means for setting channels between the adjacent video telephone/teleconference terminals in the ISDN so that said plurality of video telephone/teleconference terminals may be connected in a ring configurations;

wherein each of said video telephone/teleconference terminals comprises;

generation means for generating said video telephonic/teleconferential data which is to be sent to the other video telephone/teleconference terminals,

relay means for relaying the communication frame received from the video telephone/teleconference terminal at an upper stream position of a loop to the video telephone/teleconference terminal at a lower stream position of said loop so that said communication frame may revolve around said loop, said loop being formed of said plurality of video telephone/teleconference terminals and said channels set by said channel setting means so as to connect said video telephone/teleconference terminals,

transmission means for entering the generated video telephonic/teleconferential data into said communication frame which is to be relayed by said relay means, thereby transferring said generated video telephonic/teleconferential data to said other video telephone/teleconference terminals which lie on said loop, and

cancellation means for canceling the video telephonic/teleconferential data which was entered into said communication frame by said transmission means of a video telephone/teleconference terminal itself before and which has revolved around said loop, from within said communication frame which is to be relayed by said relay means;

wherein said communication frame is a frame stipulated in CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frame"), and a frame stipulated in CCITT Recommendation H. 261 (herein below, termed "H. 261 frame") is prepared in said H. 221 frame;

wherein each of said video telephone/teleconference terminals further comprises audio data resumption means for resuming audio data into speech so as to emit the speech;

wherein said generation means generates the video telephonic/teleconferential data including audio data;

wherein said cancellation means cancels an audio data component which was entered into said H. 261 frame by said transmission means of said video telephone/teleconference terminal itself and which has revolved around said loop, from audio data contained in said H. 261 frame of the received H. 221 frame;

wherein said audio data resumption means resumes the audio data with said audio data component of said terminal itself cancelled by said cancellation means, into the speech so as to emit said speech; and

wherein said transmission means enters new audio data into said H. 261 frame of the H. 221 frame to be relayed by said relay means, instead of said audio data contained in said H. 261 frame of said H. 221 frame received by said relay means, said new audio data being obtained in such a way that said audio data generated by said generation means is added to said audio data with said audio data component of said terminal itself cancelled by said cancellation means.

9. A video telephone/teleconference terminal connectable with a plurality of digital communication channels, comprising:

generation means for generating video telephonic/teleconferential data which is to be sent to a plurality of other video telephone/teleconference terminals, said telephonic/teleconferential data including video data;

resumption means for resuming said video data contained in a communication frame received from any of a plurality of set channels;

relay means for relaying the received communication frame to another of said set channels;

cancellation means for cancelling the video data which was entered into said communication frame by said video telephone/teleconference terminal itself before the reception of said communication frame, from within said communication frame which is to be relayed by said relay means; and

transmission means for entering the generated video data into an unused area of said communication frame which is to be relayed by said relay means.

10. A video telephone/teleconference terminal connectible with an ISDN, comprising:

channel setting means for setting a plurality of channels between said video telephone/teleconference terminal itself and a plurality of other video telephone/teleconference terminals in the ISDN;

generation means for generating video telephonic/teleconferential data which is to be sent to the other video telephone/teleconference terminals, said telephonic/teleconferential data including video data;

resumption means for resuming said video data contained in a communication frame received from any of the set channels;

relay means for relaying the received communication frame to another of the set channels;

cancellation means for canceling the video telephonic/teleconferential data which was entered into said communication frame by said video telephone/teleconference terminal itself before the reception of said communication frame, from within said communication frame which is to be relayed by said relay means; and

transmission means for entering the generated video data into an unused area of said communication frame which is to be relayed by said relay means.

11. A video telephone/teleconference terminal as defined in claim 10, wherein:

said communication frame is a frame stipulated in CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frame");

said resumption means resumes said video data into a picture of one picture frame so as to present a display output, said video data being contained in a plurality of groups of blocks (GOB'"'"'s) of a frame stipulated in CCITT Recommendation H. 261 (hereinbelow, termed "H. 261 frame") and prepared in the received H. 221 frame, said GOB'"'"'s each being a plurality of blocks into which the data area for H. 261 frames are divided;

said transmission means enters the generated video data into at least one GOB allotted to said video telephone/teleconference terminal itself, among said plurality of GOB'"'"'s of said H. 261 frame prepared in said H. 221 frame; and

said cancellation means cancels video data which was entered into said H. 261 frame by, said transmission means of said video telephone/teleconference terminal itself before the reception of said H. 221 frame to be relayed, from at least one GOB allotted to said video telephone/teleconference terminal itself.

12. A video telephone/teleconference terminal as defined in claim 10, wherein:

said communication frame is a frame stipulated n CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frame"), and a frame stipulated in CCITT Recommendation H. 261 (hereinbelow, termed "H. 261 frame") is prepared in said H. 221 frame;

said video telephone/teleconference terminal comprises audio data resumption means for resuming audio data into speech so as to emit the speech;

said generation means generates the video telephonic/teleconferential data including audio data;

said cancellation means cancels an audio data component which was entered into said H. 261 frame by said transmission means of said video telephone/teleconference terminal itself before the reception of said H. 221 frame, from audio data contained in said H. 261 frame of the received H. 221 frame;

said audio data resumption means resumes the audio data with said audio data component of said terminal itself cancelled by said cancellation means, into speech so as to emit said speech; and

said transmission means enters new audio data into said H. 261 frame to be relayed by said relay means, instead of said audio data contained in said H. 261 frame of said H. 221 frame received by said relay means, said new audio data being obtained in such a way that said audio data generated by said generation means is added to said audio data with said audio data component of said terminal itself canceled by said cancellation means.

13. A video telephone/teleconference terminal connectible with an ISDN, comprising:

channel setting means for setting a plurality of channels between said video telephone/teleconference terminal itself and a plurality of other video telephone/teleconference terminals in the ISDN;

generation means for generating video telephonic/teleconferential data which is to be sent to the other video telephone/teleconference terminals;

relay means for relaying a communication frame received from any of the set channels to another of the set channels;

transmission means for entering the generated video telephonic/teleconferential data into said communication frame which is to be relayed by said relay means; and

cancellation means for canceling the video telephonic/teleconferential data which was entered into said communication frame by said transmission means of said video telephone/teleconference terminal itself before the reception of said communication frame, from within said communication frame which is to be relayed by said relay means;

wherein said communication frame is a frame stipulated in CCITT Recommendation H. 221 (hereinbelow termed "H. 221 frame");

wherein said video telephone/teleconference terminal comprises resumption means for resuming video data into a picture of one picture frame so as to present a display output, said video data being contained in a plurality of groups of blocks (GOB'"'"'s) of a frame stipulated in CCITT Recommendation H. 261 (hereinbelow, termed "H. 261 frame") and prepared in the received H. 221 frame., said GOB'"'"'s each being a plurality of blocks into which the data area for H. 261 frames are divided;

wherein said transmission means enters the generated video data into at least one GOB allotted to said video telephone/teleconference terminal itself, among said plurality of GOB'"'"'s of said H. 261 frame prepared in said H. 221 frame; and

wherein said cancellation means cancels video data which was entered into said H. 261 frame by said transmission means of said video telephone/teleconference terminal itself before the reception of said H. 221 frame to be relayed, from at least one GOB allotted to said video telephone/teleconference terminal itself.

14. A video telephone/teleconference terminal connectible with an ISDN, comprising:

channel setting means for setting a plurality of channels between said video telephone/teleconference terminal itself and a plurality of other video telephone/teleconference terminals in the ISDN;

generation means for generating video telephonic/teleconferential data which is to be sent to the other video telephone/teleconference terminals;

relay means for relaying a communication frame received from any of the set channels to another of the set channels;

transmission means for entering the generated video telephonic/teleconferential data into said communication frame which is to be relayed by said relay means; and

cancellation means for canceling the video telephonic/teleconferential data which was entered into said communication frame by said transmission means of said video telephone/teleconference terminal itself before the reception of said communication frame, from within said communication frame which is to be relayed by said relay means;

wherein said communication frame is a frame stipulated in CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frame"), and a frame stipulated in CCITT Recommendation H. 261 (hereinbelow, termed "H. 261 frame") is prepared in said H. 221 frame;

wherein said video telephone/teleconference terminal comprises audio data resumption means for resuming audio data into speech so as to emit the speech;

wherein said generation means generates the video telephonic/teleconferential data including audio data;

wherein said cancellation means cancels an audio data component which was entered into said H. 261 frame by said transmission means of said video telephone/teleconference terminal itself before the reception of said H. 221 frame, from audio data contained in said H. 261 frame of the received H. 221 frame;

wherein said audio data resumption means resumes the audio data with said audio data component of said terminal itself cancelled by said cancellation means, into speech so as to emit said speech; and

wherein said transmission means enters new audio data into said H. 261 frame to be relayed by said relay means, instead of said audio data contained in said H. 261 frame of said H. 221 frame received by said relay means, said new audio data being obtained in such a way that said audio data generated by said generation means is added to said audio data with said audio data component of said terminal itself canceled by said cancellation means.

15. In multipoint video telephone/teleconference system having a plurality of video telephone/teleconference terminals which are connected to digital communication channels and which transmit and receive communication frame containing video telephonic/teleconferential data which includes video data, through the connected digital communication channels, said multipoint teleconference system comprising:

wherein said digital communication channels connect said plurality of video telephone/teleconference terminals in a ring configuration;

wherein said communication frame includes a plurality of data blocks each of which is divided from a data area of said communication frame;

wherein said data blocks are respectively allotted to the individual video telephone/teleconference terminals; and

wherein each of said video telephone/teleconference terminals comprises;

generation means for generating the video telephonic/teleconferential data which is to be sent to the other video telephone/teleconference terminals, said telephonic/teleconferential data including said video data,

resumption means for resuming said video data contained in the allotted data block of the frame received from the video telephone/teleconference terminal at an upper stream position of a loop with respect to transfer of said communication frame,

relay means for transmitting the received communication frame to the video telephone/teleconference terminal at a lower stream position of said loop so that said communication frame may revolve around said loop, said loop being formed of said digital communication channels which connect said plurality of video telephone/teleconference terminals to one another,

cancellation means for cancelling the video data which was entered into the allotted data block of said communication frame by a video telephone/teleconference terminal itself and which has revolved around said loop, from within said communication frame which is to be relayed by said relay means, and

transmission means for entering the generated video data into the allotted block of said communication frame which is to be relayed by said relay means, thereby sending said generated video data to said other video telephone/teleconference terminals which lie on said loop.

16. A video telephone/teleconference terminal connectible with a plurality of digital communication channels;

wherein;

said digital communication channels transmit communication frame;

said communication frame includes a plurality of data blocks each of which is divided from a data area of said communication frame;

said data blocks are respectively allotted to individual video telephone/teleconference terminals; and

said video telephone/teleconference terminal includes;

generation means for generating video telephonic/teleconferential data which is to be sent to a plurality of other video telephone/teleconference terminals, said telephonic/teleconferential data including video data,

resumption means for resuming said video data contained in said communication frame received from any of a plurality of channels,

relay means for relaying the received communication frame to another of said channels,

cancellation means for canceling the video data which was entered into the allotted data block of said communication frame by said video telephone/teleconference terminal itself the reception of said communication frames, from within said communication frame which is to be relayed by said relay means, and

transmission means for entering the generated video data into the allotted data block of said communication frame which is to be relayed by said relay means.