This paper establishes a new mobile electronic toll collection (m-ETC) by integrating mobile communication with radio frequency (RF) communication on microprocessor control with an e-commerce business model. A simple ETC system architecture and protocol for e-transactions from vehicles to toll stations is proposed to complete toll interaction on wireless environment. A software flow through Internet is developed to link from toll station roadside units (RSU) to car units. A car unit (CU) for vehicle, a pair of roadside units (RSU), and an e-Center are established. A data flow and an interaction protocol are created. The proposed m-ETC system can be applied to different toll/charge systems with appropriate hardware and software. Some simulation test results verify basic system performance on ETC applications. A new business model for the proposed m-ETC is organized and discussed with feasibility analysis in e-commerce demonstration.