Smartphone-assisted Prepaid Meter System Using BLE IoT Sensors for Smart Cities

Prepaid meter system provides consumers with better management of energy consumption. It also helps suppliers recover revenue by reducing operational cost and electricity fraud. However, a typical prepaid meter system has several limitations such as human intervention in credit recharging procedure and consumer's difficulty in figuring out the remaining credit balance; and utility company's difficulty in energy monitoring for customized services. This paper proposes a smartphone-assisted prepaid meter system using Bluetooth low energy (BLE) Internet of Things (IoT) sensors to over-come those limitations. A smartphone detects a prepaid meter based on proximity service, transfers purchased credits into the prepaid meter without human intervention. In addition, whenever consumers return home, using IoT sensors, their smartphone detects the prepaid meter, collects energy usage information and the remaining credit balance, and transfers them to the central server for energy monitoring. For feasibility analysis, latency for meter detection and probability of packet collision between neighboring meters are evaluated. The results show that a smartphone detects a prepaid meter, recharges it, and collects energy information in tens of seconds. Therefore, the smartphone-assisted prepaid meter system using BLE IoT sensors is shown to be feasible in real residential homes and expected to proliferate a prepaid meter system thanks to easy credit recharging and energy monitoring services without human intervention.