Hybrid Unicast Multicast Proxy for Live Streaming Bandwidth

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Solution Overview

Problem

The high peak-to-mean ratio in traffic volumes during live content streaming events leads to inefficient network usage and quality degradation, as existing unicast-based HTTP(S) content delivery results in identical content being delivered separately to each client, causing network overload and quality of service issues.

Innovation Solution

A method that switches from unicast to multicast delivery based on estimated delivery rates, where the multicast rate is set as a function of the unicast request rate, allowing for efficient delivery of common content segments to multiple clients without requiring access to manifests, using a hybrid unicast/multicast network architecture with proxy servers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If unicast delivery is used for each client device, then individual content delivery is achieved, but network bandwidth is wasted due to duplicate transmission of identical content segments

Engineering Contradiction:
Improvenetwork bandwidth usageVSAvoidcontent delivery efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent merges multiple unicast delivery streams into a single multicast stream when multiple clients request the same content segment. The system monitors request patterns and transitions to multicast delivery for commonly requested segments, thereby consolidating network resource usage and eliminating redundant transmissions while maintaining individualized delivery capability when needed.

Inventive Principle:
Principle #5Merging (Combining)

2Quantity of substance

If multicast delivery is used for content segments, then network bandwidth is optimized by delivering identical content once to multiple clients, but determining appropriate multicast rates becomes complex without access to manifest files

Engineering Contradiction:
Improvenetwork bandwidth efficiencyVSAvoidmulticast rate determination complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent introduces a mediator component that sits between the content delivery system and clients, monitoring request patterns and making intelligent decisions about when to switch from unicast to multicast delivery. This intermediary analyzes segment request frequencies and automatically determines optimal multicast rates based on observed traffic patterns, eliminating the need for complex manifest parsing while achieving efficient bandwidth utilization.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If hybrid unicast/multicast architecture with proxies is implemented, then content delivery efficiency is improved, but system complexity increases due to additional network elements

Engineering Contradiction:
Improvecontent delivery efficiencyVSAvoidnetwork architecture complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements proxy servers with multi-functional capabilities that can operate in multiple modes: transparent unicast forwarding, multicast group management, request pattern analysis, and automatic unicast-to-multicast switching. These universal proxies handle various delivery scenarios within a single architectural framework, reducing overall system complexity compared to having separate dedicated systems for each delivery mode while maintaining high content delivery efficiency.

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

Data Source

PatentEP4022862B1Content delivery
Publication Date: 2024.12.11 BRITISH TELECOM PLC
  • EP4022862B1 patent drawingFigure 1
  • EP4022862B1 patent drawingFigure 2
  • EP4022862B1 patent drawingFigure 3

AI summary

Described is a method of managing a network for delivering content in a hybrid unicast/multicast network, where content is requested by clients over unicast, but all or some of the content is delivered in part over multicast. A client requests content (in the form of segments) and receive the responses (segments) over unicast via a first proxy. The first proxy measures the time between requests and associated requested segment sizes. These measurements are used to effectively determine a unicast request rate given by the segment size divided by the time between requests. Subsequent requested segments can then be delivered over multicast over a portion of the route to the client using a multicast rate that is set as a function of (for example, 110% of) the unicast request rate. In general, the multicast path will be from a second proxy to the first proxy.