Priority controlled transmission of multimedia streams via a telecommunication line

• US 5,745,380 A
• Filed: 06/06/1995
• Issued: 04/28/1998
• Est. Priority Date: 01/30/1995
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kownatzki, Boris, Sandvoss, Jochen
• Primary Examiner(s): Kizuo, Hassan
• Assistant Examiner(s): Yao, Kwang Bin
• Application Number:
  US08/468,175
• Time in Patent Office: 1,057 Days
• Field of Search: 364/514 A, 364/514 R, 364/554, 370/79, 370/80, 370/85.6, 370/433, 370/437, 370/455, 370/465, 340/825.5, 340/825.51, 379/202, 379/243, 379/250, 379/258
• US Class Current: 379/90.01
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04N 7/152 Multipoint control units therefor

Abstract

Disclosed are a method, a system and a device for the transmission of multimedia streams via telecommunication lines. Especially, the disclosure relates to information transfer in video or audio teleconferences. The invention provides a scale of priorities for active transmission of the streams, wherein the priority status of each stream is changed dynamically with respect of attributes of substreams of the multimedia streams. Only the streams with the highest priority levels are actively transmitted.

Claims

1. A method for transmitting multimedia streams via at least one telecommunication line, each multimedia stream having at least two substreams, with at least one of the substreams having an attribute for controlling the priority of at least one of the multimedia streams, the method comprising:

a. continuously detecting changes in attributes of the substreams;

b. providing a scale of priorities for the active transmission of the multimedia streams;

c. dynamically changing the priority status of each multimedia stream according to the change of at least one of the attributes; and

d. actively transmitting only those of the multimedia stream(s) with the highest priority level(s).

2. A method as recited in claim 1, wherein the priorities of the multimedia streams are determined by a weighting function ##EQU2## wherein loud(s_i,A(S_i)) is the amplitude of an audio substream s_i at time A(s_i), where A(s_i) indicates when the substream was previously active, where A(s_i) is the the current time t if multimedia stream s_i is currently active, where A(s_i) equals zero if multimedia stream s_i was never active, and where A(s_i) equals t_k if multimedia stream s_i is currently in a passive state, where t_k is the last time the multimedia stream s_i was active and wherein loud_max is the maximum amplitude of said substream.

3. A method as recited in claim 1, wherein a user selects the maximum number of streams which can be active in parallel.

4. A method as recited in claim 3, wherein said method is applied at a sender site, or at a receiver site, or at an intermediate control system.

5. A method as recited in claim 1, wherein said method is applied at a sender site, or at a receiver site, or at an intermediate control system.

6. A method as recited in claim 1, further comprising:

a. detecting the amplitudes of the audio substream;

b. setting each of the multimedia streams into either an active or passive state, where at least one of the multimedia streams is set in an active state for transmission;

c. assigning to each multimedia stream a priority for active transmission; and

d. dynamically changing the priority of each multimedia stream in response to changes in the amplitudes of the audio substream in each multimedia stream.

7. A method as recited in claim 6, wherein each priority assigned to each multimedia stream is determined by a weighting function ##EQU3## wherein said loud(s_i,A(s_i)) is the amplitude of an audio substream s_i and A(s_i) indicates when said substream s_i was previously active, where A(s_i) is the the current time T if multimedia stream s_i is currently active, where A(s_i) equals zero if multimedia stream s_i was never active, and where A(s_i) equals T_k if multimedia stream s_i is currently in the passive state, where T_k is the last time the multimedia stream s_i was active and wherein loud_max is the maximum amplitude of an audio signal.

8. A method as recited in claim 6, wherein each said multimedia stream is selected for the active state if the amplitude of its audio substream exceeds a first threshold in a prescribed time interval, and wherein each selected multimedia stream is selected for the passage state if the amplitude of its audio substream is below a second threshold for a time period longer than a selected minimum time period.