Multipoint teleconference system employing H. 221 frames

• US 5,402,418 A
• Filed: 07/15/1992
• Issued: 03/28/1995
• 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): Chin, Wellington
• Assistant Examiner(s): VU, HUY DUY
• Application Number:
  US07/913,403
• Time in Patent Office: 986 Days
• Field of Search: 370/62, 370/58.1, 370/110.1, 370/94.1, 370/94.2, 370/99, 379/100, 379/53, 379/54, 379/205, 379/204, 379/94.1, 379/95, 380/9, 348/15
• US Class Current: 370/264
• CPC Class Codes: H04M 3/562 where the conference facilities are distributed
• CPC Class Codes: H04M 3/567 Multimedia conference systems
• CPC Class Codes: H04N 7/147 Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals selecting H04Q
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04N 7/152 Multipoint control units therefor
• 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 enters control information for controlling a multipoint teleconference, into a predetermined area within the communication frame, and it relays the resulting communication frame to the next terminal.

Claims

1. A multipoint teleconference system having an ISDN in which frames stipulated in the CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frames" are transferred around set channels, and a plurality of video telephone/teleconference terminals which conform to the CCITT Recommendation H. 320 and which are connected to the ISDN;

comprising;

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

a system controller for controlling setting of channels among the individual video telephone/teleconference terminals within said ISDN so that said plurality of video telephone/teleconference terminals connected in a ring shape; and

wherein each video telephone/teleconference terminals comprises;

relay means for relaying a received H. 221 frame so as to revolve around the ring shape which is formed of said plurality of video telephone/teleconference terminals and said channels set by said system controller to connect said plurality of video telephone/teleconference terminals, and

control information transmission means for entering control information serving to control a multipoint teleconference, into said H. 221 frame which is to be relayed by said relay means, as at least one of MLP data and BAS data, said MLP data being message data of a multilink procedure and said BAS data being command data stored in an area of an H. 221 which is stipulated in the CCITT Recommendation H. 221.

2. A multipoint teleconference system as defined in claim 1, wherein:

said each video telephone/teleconference terminal comprises;

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

video data transmission means for entering the generated video data into said H. 221 frame which is to be relayed by said relay means.

3. A multipoint teleconference system having an ISDN in which frames stipulated in the CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frames") are transferred around set channels, and a plurality of video telephone/teleconference terminals which conform to the CCITT Recommendation H. 320 and which are connected to the ISDN;

comprising;

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

a system controller for controlling setting of channels among the individual video telephone/teleconference terminals within said ISDN so that said plurality of video telephone/teleconference terminals connected in a ring shape;

wherein each video telephone/teleconference terminal comprises;

relay means for relaying a received H. 221 frame so as to revolve around the ring shape which is formed of said plurality of video telephone/teleconference terminals and said channels set by said system controller to connect said plurality of video telephone/teleconference terminals, and

control information transmission means for entering control information serving to control a multipoint teleconference, into said H. 221 frame which is to be relayed by said relay means, as at least one of MLP data and BAS data, said MLP data being message data of a multilink procedure and said BAS data being command data stored in an area of an H. 221 which is stipulated in the CCITT Recommendation H. 221; and

wherein said each video telephone/teleconference terminal further comprises;

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

video data transmission means for entering the generated video data into said H. 221 frame which is to be relayed by said relay means;

said control information transmission means of each of said plurality of video telephone/teleconference terminals except a specified one enters an identification of the video telephone/teleconference terminal desired to receive, into said H. 221 frame as said control information;

said video data transmission means enters the video data into said H. 221 frame in accordance with a content of a command in a case where the received H. 221 frame contains the control information commanding said video telephone/teleconference terminal itself to transmit said video data; and

said control information transmission means of the specified video telephone/teleconference terminal enters the control information for command the video telephone/teleconference terminal indicated by the identification to transmit the video data, into said H. 221 frame in a case where the received H. 221 frame contains said identification of said video telephone/teleconference terminal desired to receive said video data, said identification having been transmitted from any of said video telephone/teleconference terminals.

5. A multipoint teleconference system as defined in claim 3, wherein said specified video telephone/teleconference terminal comprises a display unit which presents the content of the command as a display output when said control information transmission means enters the control information for commanding the video telephone/teleconference terminal to transmit the video data, into said H. 221 frame.

4. A multipoint teleconference system having an ISDN in which frames stipulated in the CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frames") are transferred around set channels, and a plurality of video telephone/teleconference terminals which conform to the CCITT Recommendation H. 320 and which are connected to the ISDN;

comprising;

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

a system controller for controlling setting of channels among the individual video telephone/teleconference terminals within said ISDN so that said plurality of video telephone/teleconference terminals may be connected in a ring shape;

wherein each video telephone/teleconference terminal comprises;

relay means for relaying a received H. 221 frame so as to revolve around the ring shape which is formed of said plurality of video telephone/teleconference terminals and said channels set by said system controller to connect said plurality of video telephone/teleconference terminals, and

control information transmission means for entering control information serving to control a multipoint teleconference, into said H. 221 frame which is to be relayed by said relay means, as at least one of MLP data and BAS data, said MLP data being message data of a multilink procedure and said BAS data being command data stored in an area of an H. 221 which is stipulated in the CCITT Recommendation H. 221; and

wherein said each video telephone/teleconference terminal further comprises;

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

video data transmission means for entering the generated video data into said H. 221 frame which is to be relayed by said relay means;

said each video telephone/teleconference terminal comprises means for generating audio data obtained by coding a speech, and audio data transmission means for entering the generated audio data into said H. 221 frame which is to be relayed by said relay means;

said control information transmission means of each of said plurality of video telephone/teleconference terminals except a specified one enters an audio level of the audio data entered by said audio data transmission means, into said H. 221 frame as said control information;

said video data transmission means enters the video data into said H. 221 frame in accordance with a content of a command in a case where the received H. 221 frame contains the control information commanding said video telephone/teleconference terminal itself to transmit said video data; and

said control information transmission means of the specified video telephone/teleconference terminal compares the audio levels of the individual video telephone/teleconference terminals contained as the control information in the received H. 221 frame, and it enters into said H. 221 frame the control information for commanding the selected video telephone/teleconference terminal to transmit the video data, said selected video telephone/teleconference terminal being determined in conformity with predetermined rules and in accordance with a result of the comparison.

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

said each video telephone/teleconference terminal comprises a display unit which presents a picture indicated by the received video data, as a display output; and

said specified video telephone/teleconference terminal comprises means for delivering the content of the command to said display unit when said control information transmission means enters the control information for commanding the video telephone/teleconference terminal to transmit the video data, into said H. 221 frame.

7. A multipoint teleconference system having an ISDN in which frames stipulated in the CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frames") are transferred around set channels, and a plurality of video telephone/teleconference terminals which conform to the CCITT Recommendation H. 320 and which are connected to the ISDN;

comprising;

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

a system controller for controlling setting of channels among the individual video telephone/teleconference terminals within said ISDN so that said plurality of video telephone/teleconference terminals connected in a ring shape; and

wherein each video telephone/teleconference terminal comprises;

relay means for relaying a received H. 221 frame so as to revolve around the ring shape which is formed of said plurality of video telephone/teleconference terminals and said channels set by said channel system controller to connect said plurality of video telephone/teleconference terminals, and

control information transmission means for entering control information serving to control a multipoint teleconference, into said H. 221 frame which is to be relayed by said relay means, as at least one of MLP data and BAS data, said MLP data being message data of a multilink procedure and said BAS data being command data stored in an area of an H. 221 which is stipulated in the CCITT Recommendation H. 221;

each of said plurality of video telephone/teleconference terminals except a specified one comprises channel alteration means for altering a connection destination of the channel to which said video telephone/teleconference terminal itself is connected, in accordance with a content of a command in a case where the received H. 221 frame contains said control information commanding said terminal itself to alter said connection destination of said channel and said control information transmission means thereof enters a desire to leave the teleconference, into said H. 221 frame as said control information; and

said control information transmission means of the specified video telephone/teleconference terminal enters new control information into said H. 221 frame in a case where said control information indicating a desire to leave the teleconference as transmitted from any of said video telephone/teleconference terminals is contained in the received H. 221 frame, said new control information commanding said channel alteration means of another video telephone/teleconference terminal to alter said connection destination of said channel so that the video telephone/teleconference terminal having transmitted said control information indicating said desire to leave said teleconference may be disconnected from said loop, and two of said video telephone/teleconference terminals which were connected with said video telephone/teleconference terminal having transmitted said control information indicating said desire to leave said teleconference are connected directly.

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

said each video telephone/teleconference terminal comprises a display unit which presents a picture indicated by the received video data, as a display output; and

said specified video telephone/teleconference terminal comprises means for delivering the content of the command to said display unit when said control information transmission means enters the control information for commanding said channel alteration means to alter said connection destination of said channel, into said H. 221 frame.

9. A video telephone/teleconference terminal which is constructed in conformity with the CCITT Recommendation H. 320, comprising:

means for communicating using a frame stipulated in the CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frame"), as a communication frame containing MLP data, MLP data which is message data of a multilink procedure; and

means for entering control information serving to control a multipoint teleconference, as the MLP data into the H. 221 frame, and for transmitting said H. 221 frame.

10. A video telephone/teleconference terminal which is constructed in conformity with the CCITT Recommendation H. 320, comprising:

means for communicating using a frame stipulated in the CCITT Recommendation H. 221 (hereinbelow, termed "H. 221 frame"), as a communication frame containing BAS data which is command data stored in an area in a H. 221 frame which is stipulated in the CCITT Recommendation H. 221; and

means for entering control information serving to control a multipoint teleconference, as the BAS into the H. 221 frame, and for transmitting said H. 221 frame.