Guaranteeing Reliable Communications in Mesh Beacon-Enabled IEEE802.15.4 WSN for Industrial Monitoring Applications

Wireless Sensor Networks (WSN) are a very promising solution for industrial monitoring applications in terms of safety, costs, efficiency and productivity. However, in order to move from the adopted manual/wired designs to wireless designs, certain guarantees must be assured, especially in terms of reliability, bandwidth and message transmission delays. Although quality of service (QoS) requirements can be satisfied in star based topologies using the Guaranteed Time Slots (GTS) feature of the IEEE802.15.4 standard, GTS communications in multihop scenarios are currently limited by IEEE802.15.4 beacon scheduling designs and peer-to-peer GTS allocation methods. This restricts applications to run over sensors that are within radio range of the network coordinator. In this work, we propose a distributed IEEE802.15.4 MAC modification to improve GTS usability and scalability in mesh networks. Also, we propose a reactive multihop GTS allocation technique based on our MAC modification to ensure reliable and latency aware end-toend communications. Results show that our techniques improve greatly the reliability of multihop GTS communications.