Toward Anycasting-Driven Reservation System for Electric Vehicle Battery Switch Service

Electro-mobility has become an increasingly important research problem in urban cities. Due to the limited electricity of battery, electric vehicle (EV) drivers may experience discomfort for long charging waiting time. Different from plug-in charging technology, we investigate the battery switch technology to improve EV drivers' comfort (e.g., reduce the service waiting time from tens of minutes to a few minutes), by benefiting from switchable (fully recharged) batteries cycled at charging stations (CSs). Since demand hotspot may still happen at CSs (e.g., running out of switchable batteries), incoming EVs may need to wait for additional time to get their battery switched, and thus, the EV drivers' comfort is degraded. First, we propose a centralized reservation-enabling service, considering EVs' reservations (including arrival time, expected charging time of their batteries to be depleted) to optimally coordinate their battery switch plans. Second, a decentralized system is further proposed, by facilitating the vehicle-to-vehicle anycasting to deliver EV's reservations. This helps to address some of the privacy issues that can be materialized in a centralized system and reduce communication cost (e.g., through cellular network for reservation making). Results under the Helsinki city scenario show a tradeoff between comparable performance (e.g., service waiting time, number of switched batteries) and cellular network cost for EVs' reservations delivery.