Fair downlink traffic scheduling for energy sustainable vehicular roadside infrastructure

Abstract

In this paper, the timeslot based traffic scheduling problem is considered with the objectives to fairly and energy efficiently serve the vehicles. The contact durations between the vehicles and the RSU are slotted into timeslots, during each of which one unit of the traffic can be transmitted from the RSU to one vehicle, and then one unit of vehicle's requirement can be satisfied. The downlink traffic scheduling cost is defined as the transmission energy cost to deliver the traffic. The fairness of the traffic scheduling strategy is evaluated by the Jain's fairness index of the unsatisfied vehicle requirements. The proposed problem is formulated as a three-step optimization problem. To address the difficulty of the three-step optimization problem, a flow network based algorithm is proposed. Both the offline and the online traffic schedule strategies are derived. Simulation results show that the derived offline traffic scheduling strategy outperforms the original energy optimal traffic scheduling strategy in terms of fairness, while the transmitted traffic and the transmission energy cost remains almost the same. The derived online traffic scheduling strategy outperforms the existing GMCF algorithms in terms of fairness, at the expense of larger transmission energy, and with the same total transmission traffic.

Downlink Traffic Scheduling with Contact Durations Awareness for Vehicular Infrastructures

“…The contact duration is defined as a time period, starting from the instant when the vehicle drives into the transmission area of the RSU and ending at the instant when the vehicle drives out of the transmission area of the RSU. During the contact duration, the RSU can use power control technology to transmit traffic to the passing by vehicles in a constant data rate [11][12][13]. Thus, the contact duration can be slotted and during each timeslot one unit of traffic (or one bundle) can be assumed to be transmitted from the RSU to the vehicle.…”

“…Reference [13] studies a jointly optimization problem, which aims to fairly serve the vehicles while minimizing the total energy cost. The proposed problem is a three-step optimization problem which is however proved to be optimally solved in a flow network method.…”

Energy-efficient data dissemination strategy for roadside infrastructure in VCPS

“…Hammad et al [18] use this information to reduce the energy cost of the downlink infrastructure-to-vehicle data dissemination. In [19], to obtain a energy-efficient data dissemination strategy, authors classify the energy efficiency problem into three categories and formulate them as a three-step optimization problem. In [20] and [21], two different on/off sleep data dissemination strategies are proposed.…”