Detailed Explanation of Google Cast Technology: Core Protocol Analysis of Wireless Screen Mirroring

1. Technical Architecture Analysis

Working Principle

• Device discovery mechanism: Uses mDNS (Multicast DNS) for automatic device identification and service announcement on the same network.
• Connection establishment process: Establishes a secure communication channel through TLS encryption after device pairing.
• Data transmission protocol: Adopts HTTP-based streaming protocols (e.g., HLS, DASH) for content delivery and synchronization.

Protocol Features

• Low-latency transmission: Optimized for real-time scenarios, reducing delay to within milliseconds.
• High-quality encoding: Supports advanced codecs like VP9 and H.265 for clear video even at low bandwidth.
• Stable connectivity: Built-in reconnection mechanisms to maintain links during temporary network fluctuations.

2. Device Compatibility

Sender Devices

• Android phones/tablets: Natively integrated with Cast functionality via system settings.
• Chrome browser: Supports casting from Windows, macOS, and Linux through its built-in Cast extension.
• Cast-enabled apps: Applications (e.g., YouTube, Netflix, Google Photos) with direct Cast integration for content projection.

Receiver Devices

• Chromecast: Dedicated streaming adapters designed for Google Cast (Chromecast, Chromecast Ultra).
• Smart TVs: Televisions with built-in Cast support (e.g., Android TV models, select brands like Sony, LG).
• Cast-enabled speakers: Audio devices that can receive and play casted music/audio content.

3. Application Advantages

• Cross-platform compatibility: Works seamlessly across Android, iOS, Windows, and macOS ecosystems.
• Easy deployment: Requires no complex configuration—just network connectivity and a few simple steps.
• Cost-effectiveness: Low hardware requirements, with many devices supporting Cast natively without additional costs.
• Continuous updates and maintenance: Regular protocol upgrades and security patches from Google ensure long-term reliability.