Modeling and Analysis of the Local Delay in an MEC-Based VANET for a Suburban Area

Abstract

Local delay is a main component of data transmission delay in a mobile-edge computing (MEC)-based vehicular <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ad hoc</i> network (VANET). To reduce the local delay, there is a need for investigating the impacts of underlying network parameters on the local delay through performance modeling and analysis in order to provide a guideline for the deployment of edge nodes. This article considers the local delay problem in an MEC-based VANET and focuses on the local delay analysis in a suburban scenario where a vehicle node driving on a street needs the computing service from an edge node. To this end, a closed-form analytical model is derived for the uplink local delay and downlink local delay, respectively, based on stochastic geometry. In deriving the analytical model, it is assumed that vehicle nodes on each street are distributed following an independent 1-D homogeneous Poisson point process (PPP), and the edge nodes are deployed at each intersection with a certain probability. Meanwhile, carrier sense multiple access (CSMA) is employed by both vehicle and edge nodes in channel access, which is different from those considered in most existing local delay models for VANETs. Based on the derived analytical model, the impacts of underlying network parameters on the local delay are investigated through numerical results. The derived local delay model can be used to provide a guideline for the deployment of edge nodes.