  Realizing the industrial Internet of Things, more andmore mobile use cases
will emerge in the industrial landscape,requiring both novel concepts and
smooth integration into legacydeployments.Since accurate time synchronization
is particularly challengingfor wireless devices, we propose a concept for
simple but accuratesynchronization in IEEE 802.11 wireless local area network
thatextends the Reference Broadcast Infrastructure Synchronizationprotocol, and
a suitable integration of IEEE 802.1AS that is partof the IEEE time-sensitive
networking standards. In addition,the concept is evaluated with a testbed using
commercial off-the-shelf hardware and a realistic discrete automation
demonstratorequipped mostly with industrial components. By using the
afore-mentioned devices for wireless communications, this concept canbe
directly applied in existing industrial solutions, thus achievingthe proposed
results. It is shown that the achieved synchronicity issuitable for a wide
range of mandatory mobile use cases, which aremost important for a fully
functional industrial Internet of Things.
