QoS-Aware DDS–oneM2M Interworking Proxy Entity for Real-Time IoT

Abstract

Data Distribution Service (DDS) is a data-centric publish-subscribe middleware widely adopted in real-time and industrial Internet of Things (IoT) systems, providing rich Quality of Service (QoS) controls that govern timing, reliability, and resource usage. oneM2M is a global IoT service layer standard that offers a uniform resource-based interface across heterogeneous domains. Despite both standards being actively deployed in industrial and smart-city contexts, no mechanism for interworking between them has been defined. The existing oneM2M Interworking Proxy Entity (IPE) approaches for protocols such as Modbus, and Matter focus solely on data-model mapping and do not address QoS semantics. This paper proposes a QoS-aware IPE that bridges DDS and oneM2M. We classify the DDS QoS policies into three preservation levels according to their representability in the oneM2M resource model, and IPE runtime enforceability. We implement and evaluate the data-path policies that affect sample forwarding, retention, and runtime violation detection. We define a corresponding oneM2M resource structure, including a ddsQoSProperties custom attribute carried in flexContainer resources. We implement the IPE and evaluate data-path DDS QoS policies with respect to QoS mapping correctness, end-to-end latency, and runtime QoS violation detection. Results show that the IPE preserves RxO compatibility and representative QoS behaviors for the evaluated data-path policies. Across all fixed-rate configurations from 20 to 100 Hz, the median end-to-end latency stays at approximately 4 ms, with the median IPE processing segment at approximately 0.1 ms, dominated by oneM2M CSE resource creation and notification delivery.