Traffic analyzer front-end for complex IEEE 802.15.4 applications

The last years have seen a proliferation of the use of wireless communication in different applications. The systems range from simple 2-nodes communication to complex mesh systems capable of covering vast areas. Debugging such systems, especially large mesh networks can be a daunting task. There are few tools that can help. In this paper, we present and discuss the results of a monitoring tool we are developing. The system is modular, based on a deterministic multicore processor. In the proof of concept, each monitoring probe is equipped with several IEEE802.15.4 transceivers, making it possible to monitor several wireless channels at the same time and to implement a mitigation of diversity issues in the monitoring. The transceivers could also be used to generate test frames for the system under test if necessary. The parallel architecture makes it easy to add new modules and to synchronize the sniffers with the most appropriate methods. In this phase of the work, we used DCF77 to synchronize the nodes. The collected data is sent to a common host for analysis with appropriate tools. The results show that the architecture is appropriate and that synchronization should be improved

MAC Protocols for Industrial Delay-Sensitive Applications in Industry 4.0: Exploring Challenges, Protocols, and Requirements

The Industrial Internet of Things (IIoT) is expected to enable Industry 4.0 through the extensive deployment of low-power devices. However, industrial applications require, most of the time, high reliability close to 100% and low end-to-end delays. This corresponds to very challenging objectives in wireless (lossy) environments. This delay can be disastrous in time-sensitive industrial IoT deployments where immediate detection and actions impact security, safety, and machine failures. With an efficient MAC protocol, data will be provided quickly to enable the IoT to be fully effective for mission-critical applications. Efficient medium sharing is even more difficult in IIoT due to ultra-low latency, high reliability, and high quality of service (QoS) compared to best-effort for IoT. This article does not survey all existing MAC protocols for IoTs, which was already done in other works. The goal of this paper is to analyze existing MAC protocols that are more suitable for IIoT

On the Implementation and Performance Assessment of a WirelessHART Distributed Packet Analyzer

Wireless sensor networks are nowadays a reality. The wide consensus gained by the IEEE 802.15.4 standard has facilitated the adoption of wireless links not only in the consumer world but also as a valid replacement of traditional wired industrial networks. In particular, the physical layer specs of IEEE 802.15.4 comply with the critical requirements of industrial applications as low cost and low power. The most remarkable example of this strategy is WirelessHART (WH), which is the first wireless fieldbus based on an open standard and specifically designed for process measurement and control applications. It uses traditional IEEE 802.15.4 radios but adopts a synchronized time-division medium-access strategy and relies on HART protocol for the upper layers. Its mesh topology allows for efficient and reliable coverage of large areas. It was presented in September 2007, but test specifications have officially been released just a few months ago, together with the announcement of the "Wireless Test System", which is only available to HART consortium members. In this paper, the authors deeply discuss the design and performance of a new and innovative packet analyzer purposely designed for the WH protocol. To the authors' knowledge, it is the first instrument that pursues a distributed approach so that it can be used both for laboratory tests and for on-the-field measurements during the plant commissioning. It is capable to simultaneously scan all available RF channels and to furnish packet timestamping with accuracy on the order of microsecond, as verified by an extensive measurement campaign. In addition, a dissector for the well-known WireShark software has also been implemented and described, providing a very simple and intuitive analysis. Moreover, the proposed instrument has been interfaced with a preliminary version of the analysis software supplied by the HART consortium