  In-person human interaction relies on our spatial perception of each other
and our surroundings. Current remote communication tools partially address each
of these aspects. Video calls convey real user representations but without
spatial interactions. Augmented and Virtual Reality (AR/VR) experiences are
immersive and spatial but often use virtual environments and characters instead
of real-life representations. Bridging these gaps, we introduce DualStream, a
system for synchronous mobile AR remote communication that captures, streams,
and displays spatial representations of users and their surroundings.
DualStream supports transitions between user and environment representations
with different levels of visuospatial fidelity, as well as the creation of
persistent shared spaces using environment snapshots. We demonstrate how
DualStream can enable spatial communication in real-world contexts, and support
the creation of blended spaces for collaboration. A formative evaluation of
DualStream revealed that users valued the ability to interact spatially and
move between representations, and could see DualStream fitting into their own
remote communication practices in the near future. Drawing from these findings,
we discuss new opportunities for designing more widely accessible spatial
communication tools, centered around the mobile phone.
