Multicast Client Rate Adaptation for Buffer Fill and Link Utilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing content streaming technologies face challenges in efficiently delivering multicast content with quality-level adaptation, particularly due to limitations in bitrate estimation and excessive unicast bursts, which lead to redundant transmissions and overloading of links with limited capacity.
Innovation Solution
A client device determines the input data rate during multicast transmission and sets an output data rate to manage the delivery of segments to a media player, allowing for seamless quality-level adaptation and efficient switching between unicast and multicast modes using a synchronization stream to avoid redundant transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If unicast burst is used to fill buffer during tune-in operation, then buffer filling speed is improved, but link capacity is overloaded due to redundant transmission
Solution Approach 1:
The system performs preliminary actions by having the client device join the multicast group before the actual content delivery begins. The multicast stream starts delivering content in advance, so when the client is ready to play, the buffer is already filled or nearly filled, eliminating the need for separate unicast burst operations.
Solution Approach 2:
The invention merges the tune-in operation with the regular multicast content delivery. Instead of separating the buffer-filling phase (unicast burst) from the playback phase (multicast), the system combines both functions into a single multicast stream delivery process, where the same multicast stream serves both to fill the buffer and provide content for playback.
2Adaptability or versatility
If client-side proxy is used for multicast delivery, then compatibility with existing media players is improved, but rate adaptation complexity increases
Solution Approach 1:
The media player itself performs rate adaptation by selecting which multicast groups to join based on its buffer state and playback requirements. The client device simply forwards the multicast streams without active intervention, making the system self-adapting without complex proxy logic.
Solution Approach 2:
The system introduces a simplified intermediary layer where the client device acts as a transparent forwarder between multicast groups and the media player. This intermediary does not perform complex rate adaptation but simply relays streams, while the media player autonomously selects appropriate streams based on its needs.
3Speed
If unicast and multicast delivery are used simultaneously, then buffer filling is accelerated, but redundant transmission occurs on limited capacity links
Solution Approach 1:
The multicast stream begins delivering content in advance during the tune-in operation, preliminarily filling the buffer before playback starts. This preliminary action eliminates the need for subsequent unicast bursts that would cause redundant transmission.
Solution Approach 2:
Instead of using unicast to fill the buffer and then switching to multicast (the conventional approach), the system inverts the sequence by using multicast from the beginning to both fill the buffer and provide playback content, eliminating redundant transmissions.
Data Source
AI summary
A client device (100) receives segments of streamed content in a multicast transmission mode. The client device (100) determines an input data rate associated with the receiving of the segments in the multicast transmission mode. Depending on the input data rate, the client device (100) sets an output data rate. In response to requests from a media player (140), the client device (100) outputs the received segments at the output data rate to the media player (140).