OCF-to-ZigBee (O2Z) Bridging Technique and IoTivity-Based Implementation

As the number of Internet-of-Things (IoT) devices explosively increases, developing the IoT standard is essential to control those devices efficiently. To do this, many vendors and IT companies have established IoT standard organizations. In particular, the Open Connectivity Foundation (OCF), the most influential IoT standard organization, has been actively developing the OCF standard and an open-source software framework called IoTivity. The OCF standard supports interoperability through bridging techniques toward non-OCF devices of other ecosystems, such as ZigBee, Bluetooth low energy, oneM2M, and AllJoyn. Among several bridging techniques, we focus on developing an OCF-to-ZigBee (O2Z) bridging technique which is very important to provide the scalability of the OCF standard. This is because there are many ZigBee devices to construct IoT applications (e.g., lightening, heating, and sensing), and the number of them is steadily increasing. In this article, we introduce the O2Z bridging technique adopted in the OCF standard, and describe how to implement an O2Z bridging plugin as a software component of IoTivity. This work would provide a good guideline for developing other bridging techniques toward other IoT ecosystems.