The current Dutch OV-chipkaart payment system for public transportation is based on RFID cards and requires a lot of manual actions from travellers. In this thesis, a novel automated payment system based on Bluetooth Low Energy (BLE) is proposed. Energy is an important criterion for smartphone applications. Where multiple wireless connections co-exist, interference may in uence performance. These factors must be considered when implementing the proposed system. Simulations and experiments with BLE devices are performed to derive an energy model. This model predicts energy consumption and latency for BLE under in uence of interference. The proposed system must be secure against abuse and protect the traveller's privacy. A performance analysis model and a secure, energy-efficient communication protocol are proposed. The model is applied to find that the daily energy requirement for a typical traveller is 12.6 J or less than 0.1% of a smartphone's battery capacity. During the conducted research, no threats to the feasibility of the proposed system were found. The proposed protocol can be implemented to prove the practical feasibility. Furthermore, the energy model can be applied to predict performance for other BLE applications.