  Smart manufacturing is a vision and major driver for change in industrial
environments. The goal of smart manufacturing is to optimize manufacturing
processes through constantly monitoring and adapting processes towards more
efficient and personalised manufacturing. This requires and relies on
technologies for connected machines incorporating a variety of computation,
sensing, actuation, and machine to machine communications modalities. As such,
understanding the change towards smart manufacturing requires knowledge of the
enabling technologies, their applications in real world scenarios and the
communications protocols that they rely on. This paper presents an extensive
review of wireless machine to machine communication protocols currently applied
in manufacturing environments and provides a comprehensive review of the
associated use cases whilst defining their expected impact on the future of
smart manufacturing. Based on the review, we point out a number of open
challenges and directions for future research.
