5G • 5G-Advanced (Rel-18)
Asynchronous Time Warp (ATW)
Network-Coordinated Motion Reprojection & Late Latching
Coordinates cellular frame delivery timing with on-device graphics chip reprojection, compensating for dropped packets by shifting rendered scenes.
Technical Explanation
When a network packet experiences unexpected radio delay, the headset graphics pipeline must not drop the frame, which causes severe user nausea. Asynchronous Time Warp (ATW) rotates the previous frame based on the latest IMU head position. Rel-18 coordinates frame delivery timestamps so headsets know exactly when to trigger ATW reprojection versus waiting for network frames.
Key Functions
- Coordinates cellular frame delivery timing with on-device graphics reprojection loops
- Prevents motion sickness by ensuring displays refresh at 90/120 Hz even during radio fading
- Implements late-latching protocols where latest pose data is inserted at the last millisecond
- Maximizes visual smoothness during temporary cellular interference spikes
Specifications
3GPP TR 38.835 (Rel-18)
Interfaces
Uu (User Plane)Headset Graphics Pipeline
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