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BITRATE ALLOCATION IN MULTIPARTY VIDEO CONFERENCING

IP.com Disclosure Number: IPCOM000244764D
Publication Date: 2016-Jan-11

Publishing Venue

The IP.com Prior Art Database

Related People

Sergio Mena: AUTHOR [+2]

Abstract

A system and method are provided that allocate all media sending rates in a switch-based multiparty conference. The distributed allocation algorithm maximizes the quality of experience (QoE) of all participants, adapts to changing conditions at a sub-second scale, and removes the need for transcoding. The distributed algorithm allocates the bitrates of multiple real-time media flows being transmitted in a multiparty conference. The flows can be Scalable Video Coding (SVC) layers or simulcast flows of the same captured video. The algorithm adapts to a changing speaker (or other user roles) in the sub-second time frame. The multiparty bitrate allocation algorithm is able to work together with any point-to-point congestion control algorithm for real-time media transmission. The algorithm does not rely on transcoding. An asynchronous version of the distributed bitrate allocation algorithm is provided for multiparty conferences with all the above properties.

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BITRATE ALLOCATION IN MULTIPARTY VIDEO CONFERENCING

AUTHORS:

  Sergio Mena Stefano D'Aronco

CISCO SYSTEMS, INC.

ABSTRACT

    A system and method are provided that allocate all media sending rates in a switch-based multiparty conference. The distributed allocation algorithm maximizes the quality of experience (QoE) of all participants, adapts to changing conditions at a sub- second scale, and removes the need for transcoding. The distributed algorithm allocates the bitrates of multiple real-time media flows being transmitted in a multiparty conference. The flows can be Scalable Video Coding (SVC) layers or simulcast flows of the same captured video. The algorithm adapts to a changing speaker (or other user roles) in the sub-second time frame. The multiparty bitrate allocation algorithm is able to work together with any point-to-point congestion control algorithm for real-time media transmission. The algorithm does not rely on transcoding. An asynchronous version of the distributed bitrate allocation algorithm is provided for multiparty conferences with all the above properties.

DETAILED DESCRIPTION

     Presented herein is a solution related to multiparty video conferencing in which N users connect to a multiparty conference and send/receive audio and video to/from all other users. In order to do so, users operate an application residing on an endpoint. For the sake of simplicity, the following description focuses on video transmission, but this solution can also be applied to other types for real-time data such as audio or screen sharing.

    The system model considered is as follows. All endpoints connect to an application-layer conference switch (also known as conference bridge), which is a process typically located in the cloud. The mission of the conference switch is to relay

Copyright 2016 Cisco Systems, Inc.

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video data packets and control messages among endpoints, according to a certain algorithm. Endpoints make use of adaptive video codecs: the codec's output bitrate can change over time; for instance, to adapt to the currently available bandwidth. Endpoints' video codecs are able to send video at several different bitrates simultaneously; for instance, they may feature Scalable Video Coding (SVC), or simulcast. SVC is a widespread video encoding technique whereby a base layer is encoded, providing basic quality; and then a number of incremental layers, each depending on all the previous layers, provide increasingly good quality. Simulcast is a simpler mechanism whereby the sender, starting from the same raw video frames, provides independent encoded video flows at different bitrates.

    The hardware/software capabilities of endpoints are heterogeneous: endpoints can range from low-resolution mobile devices to high-definition Telepresence units. The upload/download bandwidth available between each endpoint and the conference switch can be different and may change over time (e.g., due to changes in background traffic in the...