Energy Efficient and Reliable Wireless Sensor Networks - An Extension to IEEE 802.15.4e

TL;DR

This paper proposes a relay strategy and an extension to the IEEE 802.15.4e standard's LLDN mode, enhancing reliability and energy efficiency in industrial wireless sensor networks with two-hop communication.

Contribution

It introduces a relay-based extension and a retransmission mode for IEEE 802.15.4e LLDN, improving reliability and reducing energy consumption in industrial WSNs.

Findings

Power savings of over 33% in sensor nodes.

Packet loss reduction of up to 50%.

Optimal spatial distribution improves performance.

Abstract

Collecting sensor data in industrial environments from up to some tenth of battery powered sensor nodes with sampling rates up to 100Hz requires energy aware protocols, which avoid collisions and long listening phases. The IEEE 802.15.4 standard focuses on energy aware wireless sensor networks (WSNs) and the Task Group 4e has published an amendment to fulfill up to 100 sensor value transmissions per second per sensor node (Low Latency Deterministic Network (LLDN) mode) to satisfy demands of factory automation. To improve the reliability of the data collection in the star topology of the LLDN mode, we propose a relay strategy, which can be performed within the LLDN schedule. Furthermore we propose an extension of the star topology to collect data from two-hop sensor nodes. The proposed Retransmission Mode enables power savings in the sensor node of more than 33%, while reducing the packet loss by up to 50%. To reach this performance, an optimum spatial distribution is necessary, which is discussed in detail.