Abstract
Roadside unit (RSU) cloud and its vehicle-to-infrastructure (V2I) connectivity can enable various security, entertainment, and shared mobility applications for vehicles in intelligent transportation systems (ITS) through wireless communications. In this article, the deep programmability of software-defined networking (SDN) is employed to dynamically reconfigure network hosting services and their data forwarding information for effectively meeting the basic shared mobility applications’ needs in vehicle ad hoc networks (VANETs). Multipath is also enabled to forward data flow for balancing network links utilization rate and SDN is thus utilized to achieve the minimum cloud delay with the least number of hosts, which can be summarized as a mixed-integer linear programming (MILP) problem. The joint optimization (JO) algorithm is proposed and in contrast to the two single-objective algorithms which are the delay optimization (DO) algorithm and host optimization (HO) algorithm, respectively. Results show that, for the single-threading instance, the JO and DO algorithms are the same in essence. For the multithreading instance, the JO algorithm generally outperforms the two single-objective optimization algorithms, respectively, under given demands. Furthermore, results also demonstrate that the services should be deployed globally in a distributed manner rather than in the centralized manner for achieving the minimized cloud delay in designing an RSU cloud.
Highlights
Transportation is leading an important service industry in the national economy while traffic congestion and safety are the major problem faced by almost all core cities in the world [1]. e traditional method of controlling traffic flow based on traffic lights and stop signs cannot dynamically adjust the interval time in real-time according to the actual traffic flows
E network topology shown above represents the possible paths among the ten Roadside unit (RSU) which can be utilized to configure the allocation of the cloud resources when it comes to matching the demands of the vehicles. e left part of Figure 3 is the scenario map of the simulated area, while the right part describes the detailed topology of the designed software-defined networking (SDN) RSUs network
When the average demand comes to 86 Mbps which are the maximum bearable demands for each service in the SDN RSU cloud, the sums of cloud delay for all 3 algorithms increase substantially
Summary
Transportation is leading an important service industry in the national economy while traffic congestion and safety are the major problem faced by almost all core cities in the world [1]. e traditional method of controlling traffic flow based on traffic lights and stop signs cannot dynamically adjust the interval time in real-time according to the actual traffic flows. Variable speed limit is a major ITS technology for controlling freeway mainline traffic, which have been increasingly used to improve traffic safety and operations efficiency of freeway traffic management [2]. Ough there are some shared mobility applications, such as ride splitting, enabling riders with similar routes to share a ride sourcing trip, which is a promising transportation technology to reduce traffic congestions and air pollution, the traffic management can be enhanced through effective communications among the vehicles [4, 5]. In V2V, the communications among the vehicles are not stable enough and the quality of communication is determined by many uncontrollable factors, such as vehicle speeds, geographical locations, and weather conditions. Considering the problems that existed in the V2V communications, the RSUs are utilized for assisting the efficient communications to form the VANETs environment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
