Coexistence of Wireless Sensor Networks in Factory Automation Scenarios

Abstract

The factory automation world can take advantage from innovative wireless sensors network applications, but installation of several wireless systems in the same industrial plant will raise coexistence problems. However, in general, industrial Wireless Sensor Networks (WSNs) operate cyclically and coexistence can be obtained exploiting this characteristic. The paper proposes a methodology based on a central arbiter that assigns medium resources according to requests coming from WSN coordinators. An infrastructure (e.g. a wired Real-Time Ethernet (RTE) network) assures synchronization and distribute resource allocation results. A simulation framework has been designed to evaluate allocation scheme and WSNs coexistence before physical implementation. The real feasibility of the proposed approach has been demonstrated by means of prototype WSNs (based on IEEE802.15.4) synchronized by means of PROFINET IO RT_Class 3 network. Experimental results show a synchronization accuracy below 4 ms that allows reading of two WSNs (32 nodes) in 128 ms without collisions.

Keywords

• Wireless sensor
• Wireless network
• Synchronization
• Factory automation