Developing an Electronic Toll Collection Roadside Unit Module with an RF Transceiver

In 2019, electronic toll collection (ETC) applications saw an explosion of growth in China due to government policy. The number of cars with on-board units (OBUs) installed increased from 80 million to 200 million in just one year. Along with this OBU installation boom, the use of ETC applications was extended from expressway to city for things such as parking charges and vehicle information collection. Currently, the parking charge and vehicle information collection systems are camera based, so for ETC applications in city settings, it is desirable to integrate the ETC roadside unit (RSU) into the camera system.

This article describes an ETC RSU module implementation using the AD9361 radio frequency (RF) transceiver. Its target applications are China’s ETC RSUs, which means it must comply with the Chinese standard GB/T 20851-2019 “Electronic Toll Collection— Dedicated Short Range Communication.” The module is of quite compact size, 11 cm × 6 cm, so it is easy to integrate inside the camera system. What’s more, this ETC RSU module can also be configured as a simple RF instrument, which could be used to test the ETC RSU module in a customer’s production line. Customers would not need an expensive RF instrument in their production line, resulting in huge cost savings.