  The increasing availability of on-board processing units in vehicles has led
to a new promising mobile edge computing (MEC) concept which integrates
desirable features of clouds and VANETs under the concept of vehicular clouds
(VC). In this paper we propose an architecture that integrates VC with metro
fog nodes and the central cloud to ensure service continuity. We tackle the
problem of energy efficient resource allocation in this architecture by
developing a Mixed Integer Linear Programming (MILP) model to minimize power
consumption by optimizing the assignment of different tasks to the available
resources in this architecture. We study service provisioning considering
different assignment strategies under varying application demands and analyze
the impact of these strategies on the utilization of the VC resources and
therefore, the overall power consumption. The results show that traffic demands
have a higher impact on the power consumption, compared to the impact of the
processing demands. Integrating metro fog nodes and vehicle edge nodes in the
cloud-based architecture can save power, with an average power saving up to
54%. The power savings can increase by 12% by distributing the task assignment
among multiple vehicles in the VC level, compared to assigning the whole task
to a single processing node.
