Redundancy and Synchronisation Management in Mission- and Time-Critical Wireless Sensor Networks

Wireless sensor networks (WSNs) are a technology that has been increasingly adopted thanks to their ability to inexpensively and safely gather information in difficult-to-access environments. Because of this they are an invaluable tool to gather knowledge about health, usage, and performance parameters of products in any environment as well as identify the onset of, and avoid or mitigate, catastrophic failures. This chapter will introduce the benefits that WSNs can bring to the process of knowledge management for the development and maintenance of products as well as discuss emerging research trends regarding two prominent concerns inherent to WSNs: redundancy management and synchronisation. After reviewing these results, their impact and applicability to mission-critical applications will be discussed, as well as the interaction between the solutions

A novel technique for ZigBee coordinator failure recovery and its impact on timing synchronization

In mission critical wireless sensor networks (WSNs) accurate timestamping of the occurrence of events measured by the sensor nodes is often required together with a high degree of reliability. While precise timestamping requires synchronization of the sensor nodes, reliability is obtained by adding redundancy in all potential single point of failure nodes. In this paper, we focus on a ZigBee-based WSN using two personal area network (PAN) coordinators with different PAN identifiers (IDs) and, for this configuration, we propose a solution where if the primary PAN coordinator goes down, connections are transferred to the other by changing the PAN ID of the nodes. Our proposed solution provides significant gains in terms of recovery speed and timing synchronization accuracy in comparison to a solution that is proposed in the literature

A redundant gateway prototype for wireless avionic sensor networks

Wireless Sensor Network (WSN) technologies provide advantages that allow them to replace traditional wired systems in an ever growing number of applications. This paper describes the design of a WSN for mission critical applications such as the case of avionics, in which data collected from the sensors can be delivered to a cloud application through multiple independent gateways, thereby increasing data availability in presence of failures. Since the same data might be distributed along multiple paths, system-wide synchronization must be provided in order to guarantee data consistency. A heartbeat protocol is introduced along each path in order to guarantee timely detection of any single failure. We present a solution that can be implemented using open source software and commercial off-the-shelf hardware, which makes this approach viable for networks with a large number of heterogeneous sensors. Results reported in this paper show some sample measurements as well as the performance evaluation for our heartbeat algorithm in terms of latency between a failure and a full recovery of the system