Routing in IoT Network for Dynamic Service Discovery

Many existing IoT systems are built with predefined tasks and system architecture. To make better use of the large number of “things” availability in the IoT infrastructure, we consider to dynamically discover and compose IoT capabilities in the IoT network for new or dynamically arising tasks. To achieve the goal, we develop a semantic-based routing protocol for IoT service discovery. In the routing protocol to reduce the space requirement for routing, each node maintains a routing table with a “telescopic view”, i.e., more precise information about the capabilities of immediate neighbors and only a summary of capabilities for a further away neighborhood. We define an ontology of capabilities and design a capability summarization algorithm based on the ontology to realize the telescopic view concept. We also design an ontology coding scheme to further reduce the memory requirement for routing while enabling capability summarization. Our solutions significantly reduce the routing table size and, hence, is suitable for IoT devices with limited memory. Also, experimental results show that our approach can yield significantly lower network traffic and latency for IoT capability lookup when compared with existing semantic based routing algorithms.