Throughput and Energy Efficiency of Cooperative ARQ Strategies for VANETs Based on Hybrid Vehicle Communication Mode

Abstract

Vehicular ad-hoc networks (VANETs) are promising research areas which mainly include three communication modes: vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) and hybrid vehicle communication (HVC). But most of the current research on HVC mode in which vehicle nodes and infrastructures coexist only focuses on the analysis of the optimal single-type relay selection schemes. Inspired by this, in order to design an optimal multi-relay selection scheme which can select different types of relays simultaneously, and to compare it with single-type schemes, this paper firstly introduces a more practical network scenario by proposing a four-node system model which considers communication links between relays and building different channel models for different types of links. Four optimal relay selection protocols, which are named as Non-OR, SOR-AP, SOR-V and DOR-APV respectively, are then designed from the perspective of the different types and numbers of selected relays. The exact expressions of outage probability for each protocol are calculated based on the automatic repeat request (ARQ) protocol to evaluate the link interruption of the four protocols. Furthermore, this paper establishes a generalized 2dimensional discrete time Markov chain (DTMC) model and analyzes the one-step state transition probability for each protocol. The closed-form expressions of system throughput and energy efficiency are derived by calculating the steady state distribution of the DTMC. Finally, the simulation results summarize the suitable network scenarios for which the four proposed protocols are recommended by comparing their system performance, so as to provide some suggestions for the future design and optimization of vehicle mobile networks.

Performance Analysis of Cognitive Radio Networks With Burst Dynamics

“…Queuing model can describe the network model and analyze the system performance [10]. Therefore, it is an effective method to establish a queuing model to evaluate the performance of the secondary system in CRNs.…”

“…, where I is the identity matrix. After finite iterations (4) (3 15] is updated to [0, 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]. Finally, the matrix  after layer updating is the steady-state distribution of matrix Q with size1 32  .…”

An Optimal Relay Number Selection Algorithm for Balancing Multiple Performance in Flying Ad Hoc Networks

“…Coincidentally, this idea coincides with us. In our finished work [26], an important conclusion that under a specific communication scenario (such as the communication distance between source nodes and destination nodes), there always exists an optimal number of relays in the system which can maximize the energy efficiency has been drawn. Based on this, is it possible to design an optimal relay number selection algorithm which can dynamically adjust the number of relays according to the changing communication distance?…”

“…On the other hand, because the very high mobility is the most distinct characteristic between FANETs and traditional terrestrial networks, we further select the short-term static feature to characterize the complex FANETs time-varying channel. It is worth noting that in our finished work for typical terrestrial networks such as VANETs [26] and WSNs [31], the longterm static Rayleigh fading is chosen as the channel model. The difference between long-term and short-term static feature lies in the changing frequency of channel fading coefficient.…”

Sensing and Detection of Traffic Status through V2V Routing Hop Count and Route Energy

“…They apply real time messaging between vehicles (nodes) using radio wave transmission over specific distance (range). VANETS consist of vehicular mobile nodes, established without a centralized infrastructure, thus, each node will perform the functions of transmitter, receiver, and data router [22], [23], [24], [25], [26], [27], [28].…”