The Power of Asynchronous SLAM in Multi-User AR over Cellular Networks: A Measurement Study

With the rapid deployment of 5G, an important question is whether 5G can support latency-critical apps such as multi-user AR, which allows multiple users to interact in the same physical space in real time. Recent studies showed that a popular multi-user cloud-based AR app (Cloud Anchor) suffers long end-to-end (E2E) latency in multi-user interactions under both LTE or 5G and hence cannot be supported by today's cellular networks. In this paper, we revisit the feasibility of multi-user AR over wireless networks by experimenting with another popular multi-user AR app, Just a Line, and find that its E2E latency is in the order of a few 100s of ms over both LTE and 5G, making real-time multi-user interactions feasible. We conduct a detailed measurement study of the Just a Line app over cellular networks and uncover the drastic user-perceived performance difference between the two multi-user apps stems from two fundamentally different architecture designs of performing SLAM: asynchronous vs. synchronous updates.