Breaking edge shackles: Infrastructure-free collaborative mobile augmented reality

Collaborative AR applications are gaining popularity, but have heavy computing requirements for identifying and tracking AR devices and objects in the ecosystem. Prior AR frameworks typically rely on edge infrastructure to offload AR's compute-heavy tasks. However, such infrastructure may not always be available, and continuously running AR computations on user devices can rapidly drain battery and impact application longevity. In this work, we enable infrastructure-free mobile AR with a low energy footprint, by using collaborative time slicing to distribute compute-heavy AR tasks across user devices. Realizing this idea is challenging because distributed execution can result in inconsistent synchronization of the AR virtual overlays. Our framework, FreeAR, tackles this with novel lightweight techniques for tightly synchronized virtual overlay placements across user views, and low latency recovery upon disruptions. We prototype FreeAR on Android and show that it can improve the virtual overlay positioning accuracy (with respect to the IOU metric) by up to 78%, relative to state-of-the-art collaborative AR systems, while also reducing power by up to 60% relative to a direct application of those prior solutions.