ST's NFC system-in-package solution utilizes the standard 13.56MHZ RF interface adopted for NFC mobile phones worldwide. With Wasion's post-pay NFC power meters, consumers can use their NFC mobile phones to read smart meters via a contactless RF interface and send the encrypted data over the 2G/3G mobile network to the banking back-end to complete the electricity-fee transaction.

The system-in-package contains an NFC contactless interface (ST21NFCA) and a Secure Element (ST33F1M). The ST33F1M Secure Element embeds a secure operating system from Gemalto, based on Global Platform GP2.2/Java3.0.1, a secure near field communication (NFC) payment platform. The Java OS and Java applets provide a secure environment for the application to run and store metering data. With this level of security, the same solution can also be used for pre-pay contract users. The system-in-package is used along with an STM32 MCU and ST's EEPROM in Wasion's power meters.