  We propose a novel edge-assisted multi-user collaborative augmented reality
framework in a large indoor environment. In Collaborative Augmented Reality,
data communication that synchronizes virtual objects has large network traffic
and high network latency. Due to drift, CAR applications without continuous
data communication for coordinate system alignment have virtual object
inconsistency. In addition, synchronization messages for online virtual object
updates have high latency as the number of collaborative devices increases. To
solve this problem, we implement the CAR framework, called eCAR, which utilizes
edge computing to continuously match the device's coordinate system with less
network traffic. Furthermore, we extend the co-visibility graph of the edge
server to maintain virtual object spatial-temporal consistency in neighboring
devices by synchronizing a local graph. We evaluate the system quantitatively
and qualitatively in the public dataset and a physical indoor environment. eCAR
communicates data for coordinate system alignment between the edge server and
devices with less network traffic and latency. In addition, collaborative
augmented reality synchronization algorithms quickly and accurately host and
resolve virtual objects. The proposed system continuously aligns coordinate
systems to multiple devices in a large indoor environment and shares augmented
reality content. Through our system, users interact with virtual objects and
share augmented reality experiences with neighboring users.
