Design and implementation of flow-based programmable nodes in software-defined sensor networks

In this paper, a Software-Defined Sensor Network (SDSN) is proposed by applying Software-Defined Networking (SDN) and OpenFlow protocol into the Wireless Sensor Networks (WSNs). We firstly investigate the main system architecture of SDSN, which includes the application plane, the control plane, and the data plane. Then, we design and implement the programmable nodes, which could achieve various functions, such as topology discovery, sensor data acquisition and processing. Additionally, to realize the efficient forwarding among sensor nodes according to specific rules, we utilize the flow table with the detailed definition of the match field, action field, next hop field and Time To Live (TTL) field for each entry. Based on the design of data plane in SDSN, a physically-implemented SDSN platform can be provided. The results of experiment conducted on this platform reveal that the data plane based on flow table forwarding has lower packet loss rate.