  Industry 4.0 introduces new use cases, with more and more mobile devices
appearing in the industrial landscape. These applications require both new
technologies and smooth integration into existing brownfield deployments.
Emerging mobile use cases can be divided into optional mobile and mandatory
mobile, where the first point considers the use of wireless communications due
to soft criteria such as cost savings and the second means use cases that
cannot be covered by wireline technologies due to their movement, such as AGVs.
For most industrial applications, high determinism, E2E latency and
synchronicity are most important. Therefore, we provide a common table, based
on these requirements, listing both existing and emerging mobile use cases.
Since time synchronization is particularly demanding for wireless use cases, we
propose a concept for a simple but precise synchronization in IEEE 802.11 WLAN
and a suitable integration using TSN in combination with OPC UA technology as
examples. Furthermore, the concept is evaluated with the help of a testbed
utilizing state-of-the-art hardware. This means that this concept can be
directly applied in existing industry solutions. It can be shown that the
concept is already suitable for a wide range of the mandatory mobile
applications.
