On Minimizing the Age of Information in NOMA-Based Vehicular Networks Using Markov Decision Process

Network sustainability relies on many important parameters where the timely dissemination of information has a prime role to improve network operations and henceforth the network sustainability. Age of Information is a critical metric in many applications of future networks including smart transportation systems as these networks require fresh updates from the various network entities for the successful delivery of their services. This paper considers smart vehicles in a vehicle-to-infrastructure network where each vehicle has a stream of data for transmission to the roadside unit (RSU). The information from vehicles is collected when they enter the communication range of an RSU and stay within the coverage area of that RSU for a particular time. During this time, the RSU attempts to receive information from each vehicle as timely as possible. This paper proposes a hybrid access mechanism consisting of both orthogonal and non-orthogonal multiple access that schedules the transmission of packets from vehicles to the RSU where each vehicle has a finite length queue. The transmission of the packets is modeled using a Markov decision process, where a specific cost function is optimized to collect maximum information from the vehicles in a minimum amount of time.