  Non-Terrestrial Networks (NTNs) are expected to be a key component of 6th
generation (6G) networks to support broadband seamless Internet connectivity
and expand the coverage even in rural and remote areas. In this context, High
Altitude Platforms (HAPs) can act as edge servers to process computational
tasks offloaded by energy-constrained terrestrial devices such as Internet of
Things (IoT) sensors and ground vehicles (GVs). In this paper, we analyze the
opportunity to support Vehicular Edge Computing (VEC) via HAP in a rural
scenario where GVs can decide whether to process data onboard or offload them
to a HAP. We characterize the system as a set of queues in which computational
tasks arrive according to a Poisson arrival process. Then, we assess the
optimal VEC offloading factor to maximize the probability of real-time service,
given latency and computational capacity constraints.
