Multicast Streaming Feedback via HTTP HEAD Requests

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Solution Overview

Problem

Current multicast video streaming methods require continuous network resource allocation and are not supported by all devices, while unicast methods waste bandwidth by sending multiple copies of the same content, and there is a need for efficient switching between multicast and unicast delivery to adapt to changing network conditions and device capabilities.

Innovation Solution

A method that provides feedback on client reception through HTTP HEAD requests to manage multicast delivery, allowing switching between multicast and unicast based on client demand, using RTP and UDP protocols with additional chunk boundary markers to ensure seamless switching and resilience in packet delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If multicast transmission is used to deliver content to multiple devices simultaneously, then network efficiency is improved, but network resources are continuously allocated regardless of viewing demand and compatibility with all end devices is reduced

Engineering Contradiction:
Improvenetwork bandwidthVSAvoiddevice compatibility
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The system dynamically switches between multicast and unicast transmission modes based on real-time viewing demand. When multiple devices are viewing the same content simultaneously, multicast is used for efficiency. When viewing demand drops or individual devices require personalized content, the system transitions to unicast. This dynamic adaptation resolves the contradiction by making network resource allocation flexible rather than static.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The content delivery system is designed to support both multicast and unicast transmission protocols, making it universally compatible with different device types and network conditions. The system can serve multicast-capable devices efficiently while simultaneously supporting legacy devices and scenarios requiring individualized content delivery through unicast, thus achieving versatility across all end devices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If unicast transmission is used to deliver content to each device individually, then device compatibility is improved, but network bandwidth is wasted by sending multiple copies of the same content

Engineering Contradiction:
Improvedevice compatibilityVSAvoidnetwork bandwidth
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The system monitors viewing demand in real-time and dynamically adjusts transmission mode. When multiple devices request the same content, the system switches from unicast to multicast to conserve bandwidth. When viewing demand is low or devices require customized content streams, unicast is maintained. This dynamic adjustment eliminates continuous bandwidth waste while preserving device compatibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements feedback mechanisms to monitor viewing demand, device capabilities, and network conditions. Based on this feedback, intelligent decisions are made about whether to use multicast or unicast for each content stream. This feedback-driven approach ensures bandwidth efficiency by avoiding redundant transmissions while maintaining compatibility with all device types.

Inventive Principle:
Principle #23Feedback

3Loss of energy

If multicast delivery is used without feedback mechanisms, then network resource allocation efficiency is improved, but ability to adapt to changing viewing demand is reduced

Engineering Contradiction:
Improvenetwork bandwidthVSAvoidresponse to viewing demand
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The system implements feedback mechanisms that monitor viewing demand, active subscriber counts, and content popularity in real-time. This feedback enables the system to detect when multicast groups should be created, maintained, or dissolved based on actual usage patterns. The feedback loop ensures that multicast resources are allocated efficiently only when multiple devices are actively consuming the same content.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The multicast group management is made dynamic through continuous monitoring of viewing demand. When the number of active viewers drops below a threshold or devices leave the multicast group, the system automatically transitions to unicast or dissolves the multicast group to free network resources. This dynamic response to changing demand resolves the contradiction between resource efficiency and adaptability.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3127334B1Multicast streaming
Publication Date: 2020.10.21 BRITISH TELECOM PLC
  • EP3127334B1 patent drawingFigure 1
  • EP3127334B1 patent drawingFigure 2
  • EP3127334B1 patent drawingFigure 3

AI summary

The invention presents a method of providing feedback for receipt of a multicast video stream. The feedback mechanism allows the number of clients receiving over multicast to be determined, which can then be used to manage multicast delivery, including switching decisions between multicast and unicast. Video content is delivered over a multicast stream from a content server to a plurality of client devices. The client devices are each configured to respond at regular intervals whilst receiving the multicast video stream by transmitting an HTTP HEAD request message to the content server. The HTTP HEAD request refers to metadata relating to a manifest file associated with the video stream. The number of client devices receiving the multicast video stream is determined based on the number of HEAD requests received at the content server. The multicast video delivery can then be managed accordingly, and can also take into account the number of unicast clients that are requesting the corresponding unicast stream to the multicast stream.