  Wireless links are characterized by fluctuating quality leading to variable
packet error rates which are orders of magnitude higher than the ones of wired
links. Therefore, it is of paramount importance to investigate the limitations
of using 5G wireless links for internet of things (IoT) applications. 5G
wireless links in IoT need to assure determinism of process flows via realtime
communication anytime and anywhere, which is an utmost requirement for multiple
verticals like automotive, industrial automation and aerospace. Based on a
space-time approach, in this work, we provide novel definitions of wireless
link availability and reliability, assuming a number of access points (APs) and
end points (EPs) deployed over a fixed area. Our objective is to analyze the
availability of a service in both domains. In the space domain, we characterize
spatially available areas consisting of all locations that meet a performance
requirement with confidence. In the time domain, we propose a channel
allocation scheme accounting for the spatial availability of a cell. To
emphasize the incurred space-time performance trade-offs, numerical results are
presented, also highlighting the effect of different system parameters on the
achievable link availability and reliability.
