A distributed multi-writer multi-reader (MWMR) atomic register is an important primitive that enables a wide range of distributed algorithms. Hence, improving its performance can have large-scale consequences. Since the seminal work of ABD emulation in the message-passing networks, many researchers study fast implementations of atomic registers under various conditions. "Fast'' means that a read or a write can be completed with 1 round-trip time (RTT), by contacting a simple majority. In this work, we explore an atomic register with optimal resilience and ''optimistically fast'' read and write operations. That is, both operations can be fast if there is no concurrent write.

This paper studies a fundamental distributed primitive - approximate consensus - in connected things using wireless networks. It has been extensively studied in different disciplines, such as fault-tolerant computing, distributed computing, control, and robotics communities. To our surprise, we have not found any practical algorithm that is appropriate for our target scenario - a system of small things that have limited computation and storage capability, and use lossy wireless links to communicate with each other.