VR Bitrate Control via Viewpoint Detection and Time-Shifting

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Solution Overview

Problem

Virtual reality systems face challenges in providing low-latency rendering due to the complexity of 3D models, increasing display resolution, and limited resources in mobile devices, leading to high latency and a suboptimal user experience, especially in environments requiring high bitrates for multiple content streams.

Innovation Solution

A virtual reality environment that detects the viewer's point of view and adjusts bitrate and audio volume for virtual display screens based on their visibility, allowing for dynamic bitrate control and bandwidth allocation, enabling improved quality of experience by prioritizing screens in direct view and conserving bandwidth for peripheral screens.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high bitrate is used for all virtual display screens, then image quality is improved, but bandwidth consumption increases excessively

Engineering Contradiction:

Improveimage qualityVSAvoidbandwidth consumption

Core Design Contradiction:

Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent applies local quality by differentiating bitrate allocation based on the spatial location and importance of different virtual display screens. Screens that are closer to the user's viewpoint or more important for the application receive higher bitrates, while peripheral or less important screens receive lower bitrates. This selective quality adjustment maintains overall user experience while reducing total bandwidth consumption compared to uniform high-bitrate allocation.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If 3D rendering complexity is increased for higher resolution, then display quality is improved, but rendering latency increases

Engineering Contradiction:

Improvedisplay resolutionVSAvoidrendering latency

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent implements partial action by rendering only the portions of the virtual environment that are currently visible or likely to become visible to the user, rather than rendering the entire high-resolution 3D scene. This selective rendering approach maintains acceptable display quality in the user's field of view while significantly reducing the computational load and rendering latency associated with processing the complete high-resolution environment.

Inventive Principle:

Principle #16Partial or excessive action

3Loss of energy

If multiple content streams are delivered via multicast, then bandwidth efficiency is improved, but scalability is limited

Engineering Contradiction:

Improvebandwidth efficiencyVSAvoidsystem scalability

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent segments the content delivery system into multiple components: core content delivered via efficient multicast streams, and personalized customization data delivered via unicast connections. This segmentation allows the system to maintain bandwidth efficiency for the majority of content while using scalable unicast mechanisms for user-specific adaptations, thereby achieving both bandwidth efficiency and system scalability simultaneously.

Inventive Principle:

Principle #1Segmentation

4Adaptability or versatility

If unicast delivery is used for personalized content, then adaptability is improved, but bandwidth consumption increases

Engineering Contradiction:

Improvepersonalized content deliveryVSAvoidbandwidth consumption

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by pre-rendering and storing multiple versions of content at different quality levels and formats before delivery. This allows the system to quickly switch between different content versions based on user preferences and network conditions without requiring real-time processing, thereby achieving personalized content delivery with minimal additional bandwidth consumption compared to a single baseline version.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3793203B1Bitrate control in virtual reality (VR) environments using time-shifting and unicast delivery

Publication Date: 2022.11.02 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

A system and method for providing bitrate control for delivering media content to a plurality of virtual display (VD) screens presented in a virtual reality (VR) environment effectuated by a VR device of a subscriber based on detecting a movement in a point of view with respect the VD screens' placement within the VR environment, wherein each VD screen is configured to receive a media content channel. Responsive to detecting the movement, angular distance of each of the VD screens relative to a reference axis is computed. Weights to each of the media content channels may be assigned or updated based on the angular distance of the corresponding VD screens relative to the reference axis. Media content channels on the VD screens outside the subscriber's field of view may be time-shifted. Bandwidth of a managed bandwidth pipe may be (re)allocated based on the relative weights of the non-time-shifted media content channels for delivering the media content channels to the subscriber's VR environment responsive to selecting single bitrates for the media channels according to a channel bandwidth annealing mechanism.