This Recommendation specifies reference architecture of IoT device capability exposure (IoT DCE) which supports IoT applications in DCE devices (e.g., smart phones, tablets and home gateways) to access device capabilities exposed by IoT devices connected to the DCE device. This Recommendation clarifies the concept of the IoT DCE, identifies its general characteristics and common requirements and provides the reference architecture for the IoT DCE and relevant high-level common procedures.