Ethernet 10BASE-T1S is an Ethernet variant, mainly intended for automotive applications, that operates at 10 Mbps on a single-pair physical layer. For the half-duplex multidrop topology, the Ethernet 10BASE-T1S standard specifies the Physical Layer Collision Avoidance (PLCA) channel access method, which enables low-latency collision-free cyclic transmissions, but does not implement any mechanism within a node to differentiate between the diverse traffic flows generated. However, in automotive applications Quality of Service (QoS) support is beneficial to meet the requirements of the diverse types of flows. For this reason, this work proposes an application-level traffic shaping mechanism to provide QoS differentiation over Ethernet 10BASE-T1S networks, and discusses the end-to-end delay results obtained via OMNeT++ simulations in a realistic automotive scenario.

Modern automotive systems are evolving towards software-defined vehicles, enabling seamless updates and replacements of software components throughout the vehicle lifecycle. These advancements rely on connected services, making middleware solutions for Service-Oriented Architectures (SoAs) increasingly relevant. Among the various middleware options, MQTT has emerged as a lightweight publish/subscribe protocol. However, MQTT lacks support for prioritizing diverse kinds of communication flows. To address this limitation, a recent work in the literature proposed PrioMQTT, an extended version of MQTT that incorporates message prioritization and adopts the UDP transport protocol to enhance predictability and reduce transmission delays. Despite these enhancements, the centralized broker architecture in MQTT and PrioMQTT can lead to scalability issues under high network loads. This work discusses the challenges and design choices behind a hierarchical version of PrioMQTT, named H-PrioMQTT, that aims to reduce the communication delays in automotive networks handling a large number of flows. Preliminary results obtained through simulations in a realistic in-vehicle scenario show a reduction of the maximum end-to-end delays compared to the plain PrioMQTT.

LoRaWAN supports bi-directional communication, allowing end-devices not only to transmit data to the network server (uplink), but also to receive commands or configuration updates from the network server (downlink). Although most of the research has focused on uplink performance, downlink traffic plays a critical role in enabling control, configuration, and actuation in industrial scenarios. LoRaWAN defines three device classes that offer different Quality of Service (QoS) levels for downlink communication, but they do not specifically address reliability. This work introduces three QoS classes for LoRaWAN downlink that enable configurable trade-offs between reliability and end-device energy consumption. Moreover, this work investigates novel gateway selection strategies that dynamically schedule downlink traffic according to the required QoS levels. Preliminary simulation results show that the proposed strategy significantly improves the packet delivery ratio for downlink transmissions requiring reliability, especially in scenarios with mixed QoS requirements, at the expense of increased energy consumption.

The IEEE 802.3cg-2019 standard defines Ethernet 10BASE-T1S. With a data rate of 10 Mbps in half-duplex mode on a multidrop bus, Ethernet 10BASE-T1S is a suitable candidate for in-vehicle networks with zonal architectures to interconnect multiple sensors with the relevant zonal controller. The standard provides optional Physical Layer Collision Avoidance (PLCA) capabilities that support cyclic transmissions without collisions and provide short transmission delays. However, PLCA lacks explicit priority support, while priority is useful in automotive communications to handle different flows with diverse timing requirements. In this context, this work presents a simulative performance assessment of Ethernet 10BASE-T1S with PLCA enabled in a realistic zonal-based automotive scenario. Moreover, the paper addresses how to leverage the PLCA to offer a better Quality of Service (QoS) to the nodes that generate the most time-critical flows, discussing the delays obtained with different network configurations.

In a LoRaWAN network, a number of end-devices communicate with one or more gateways that forward the messages exchanged between the end-devices and the network server. The LoRaWAN downlink transmissions, i.e., the ones from the network server to the end-devices, have to comply with the strict regional duty cycle constraints that the relevant authorities (e.g., ETSI in Europe) impose on the gateways. However, as the gateways handle the downlink traffic of a large number of end-devices, they reach their duty cycle limits faster than the individual end-devices. This determines a traffic bottleneck, as no downlink transmissions are possible as long as the gateway exceeds the duty cycle limits. Ultimately, this situation can prevent the delivery of important downlinks, e.g., the acknowledgments, in mission-critical applications. This paper explores the rationale behind the introduction of a novel gateway selection strategy, called DL+, that dynamically schedules downlink traffic to enhance the downlink packet delivery ratio. DL+ leverages a weighted decision metrics that takes into account both signal quality parameters, such as RSSI and SNR, and the available duty cycle. Preliminary simulation results are presented that demonstrate the significant improvement of the downlink packet delivery ratio introduced by DL+ compared to existing baseline approaches, especially in dense network scenarios.

Bluetooth Low Energy (BLE) is widely used in several industrial IoT applications to save on costs and power consumption. In this context, to widen the coverage area while meeting the constraints of real-time messages, some applications require multi-hop communications with bounded delays. A few approaches in the literature support real-time traffic on BLE mesh networks, but they use offline configurations, which offer a limited flexibility when new connections are dynamically added based on the application requirements. This paper, instead, proposes a Runtime Connection Admission Control for BLE (RAC-BLE) that allows the BLE devices to accept at runtime new connection requests, provided that the relevant transmissions do not overlap with communications from other BLE devices. This way, RAC-BLE by design provides bounded delays on single-hop transmissions, thus enabling BLE-based real-time mesh networks. The paper provides a detailed description of the RAC-BLE approach, an analytical calculation of the worst case end-to-end delays and experimental performance evaluations. The results show that RAC-BLE significantly reduces the maximum end-to-end delays compared with those obtained by another approach in the literature. For instance, a delay reduction of 70% and 92% is measured in the case of one hop and five hops, respectively.

While the MQTT protocol is widely adopted in IoT applications, its usage for Industrial IoT is prevented by the lack of support for time-critical transmissions. For this reason, recent work has proposed the Prioritized MQTT (PrioMQTT) protocol, i.e., an MQTT extension that introduces message prioritization and schedules messages according to their priority, which reflects their temporal constraints. PrioMQTT succeeds in reducing the latencies of time-critical messages, but it cannot guarantee bounded delays, as the message priorities are not used by the underlying network level. For this reason, this work explores the integration of PrioMQTT with the Time-Sensitive Networking family of standards, in particular with the IEEE 802.1Q-2022, to handle multiple flows with diverse real-time requirements. The work also presents a preliminary experimental assessment on commercial-off-the-shelf devices.

MQTT is an application layer protocol that, thanks to its simplicity and low overhead, is widely used in the Internet of Things (IoT) devices typically found in home automation and consumer applications. The MQTT properties make it an interesting option also for Industrial IoT (IIoT) applications. However, MQTT is not specifically devised for IIoT applications requiring low-latency and the support for time-constrained transmissions. For this reason, this paper proposes an IIoT-enabled version of MQTT called a Prioritized MQTT (PrioMQTT) that is able to provide low latencies to time-critical messages. Unlike the standard MQTT, PrioMQTT adopts the UDP/IP stack, which is more suitable than TCP/IP for low-latency communications. Moreover, PrioMQTT introduces a mechanism to prioritize the time-critical messages over the non-time-critical ones. The combination of the UDP/IP stack and priority support in the PrioMQTT protocol is achieved while maintaining the compliance with the MQTT standard message format. As a result, PrioMQTT can be implemented on commercial-off-the-shelves (COTS) devices without hardware modifications. The paper describes the PrioMQTT protocol and investigates its performance through an assessment in a realistic industrial scenario and in comparison with the standard MQTT protocol.

Bluetooth Low Energy (BLE) is emerging as an appealing solution for several Industrial Internet of Things (IIoT) applications that require low cost and low power consumption. In particular, in this context, some applications need to collect data from sensors distributed over a wide area and require predictable behavior and real-time guarantees for processing such data with bounded delays. For this reason, some works in the literature proposed approaches that enable BLE-based real-time mesh networks. However, these approaches require offline configurations, thus limiting the flexibility and adaptability of the network. This work introduces a solution to build real-time mesh networks by enabling BLE devices to find a suitable configuration at runtime.

Industry 4.0 networks support a broad set of applications and services with diverse requirements on the communication latency and reliability. Thanks to its ability to support long-distance low-power communications with low-cost devices, LoRaWAN represents a very promising solution for Industry 4.0 applications. However, LoRaWAN does not offer different Quality of Service (QoS) classes to meet the diverse requirements of the different flows. This work discusses how to support multiple Medium Access Control (MAC) protocols on a LoRaWAN end-device and introduces flow mapping in LoRaWAN networks, addressing the relevant research challenges and exploring the basic design choices.

The Time-Sensitive Networking (TSN) set of standards allows to support on the same channel the different kinds of traffic flows that are typically found in automotive scenarios. This article proposes the introduction of online Earliest Deadline First-based scheduling in TSN to provide support for event-driven real-time traffic. The proposed approach, called Deadline-TSN, is an online approach, and therefore, unlike other approaches in the literature, it does not require complex offline schedule calculations. Moreover, Deadline-TSN is able to uniformly deal with real-time periodic and event-driven traffic flows. This article presents Deadline-TSN and provides both worst-case response time analysis and simulative assessments in realistic automotive scenarios.

Industrial applications that require low power consumption and wide coverage range may benefit from the adoption of the LoRa communication technology. Unfortunately, the Medium Access Control protocol standardized for LoRa, i.e., LoRaWAN, is not suitable for industrial contexts, as it lacks support for real-time flows. Moreover, to achieve a high number of message transmissions over LoRa while keeping low duty cycle values, a multi-hop communication protocol is required. This work discusses how to combine the support for real-time flows with multi-hop transmissions over LoRa, outlining the basic design choices. A preliminary assessment based on analytical calculations is also provided.

This work explores a network architecture that combines the Software-Defined Networking (SDN) paradigm with a partitioning system for real-time networks based on the Time-Sensitive Networking (TSN) standards. The aim of the addressed architecture is to enforce temporal isolation for the flows already foreseen at the network design time, so that their delays are not affected by the introduction of new flows in the network at run time. The work describes the design of the proposed architecture and presents a preliminary experimental assessment obtained over commercial-off-the-shelf TSN-compliant switches.

The increasing complexity of modern applications calls for more complex embedded computing resources, which integrate several processing units with specialized hardware and virtualization support on a single platform to boost the computation capabilities. These subsystems require a communication system able to support different flows with diverse real-time requirements. In this context, the Time-Sensitive Networking (TSN) family of standards plays an important role. This work proposes the design and the implementation of a framework for enabling TSN communications in heterogeneous platforms with virtualization. Preliminary experimental results are reported, which provide some insights on the limitations and advantages of the proposed framework.

The advent of commercial-off-the-shelf (COTS) heterogeneous multicore platforms is offering many opportunities in the market of embedded computing systems for many application scenarios. The integration of multiple computing elements in a single device entails impressive performance capabilities. At the same time, the increased complexity of emerging systems requires the integration of more subsystems and functionalities, among others the communication subsystem. This work deals with the desirable properties of software transmission mechanisms to enable TSN communications in heterogeneous platforms handled by a hypervisor. Moreover, preliminary simulation results provide some insights on the limits and the advantages of the investigated architectures.

Monitoring of vital parameters plays a key role in better understanding the clinical condition of hospitalized patients. In this perspective, the virtual biosensor for MEDIcal WARNing precursor (MEDIWARN) aims to help the medical team to take a prompt action in response to the evolution of patients' health condition. This paper presents the MEDIWARN network architecture and discusses the design challenges that such a system poses. Simulative assessments provide a preliminary evaluation of the system in realistic scenarios.

The IEEE 802.15.4 standard contains the specifications of protocols that are suitable for industrial applications. Each of them is tailored for a specific industrial domain. One of these protocols is the Deterministic and Synchronous Multichannel Extension (DSME), which targets general industrial and commercial application domains. The DSME protocol extends the classic IEEE 802.15.4 protocol, overcoming the limitation on the maximum number of Guaranteed Time Slots (GTSs) and providing for channel diversity to increase network robustness. However, the DSME protocol suffers from scalability problems due to the rigid structure of the DSME multi-superframe, which in large networks does not allow to handle GTSs in an efficient way. To overcome this limitation, this work proposes the Shared DSME, an approach to handle the GTSs within the multi-superframe in an efficient way, thus increasing the scalability of the DSME protocol.

Future industrial networks are envisioned to support a broad set of applications and services with diverse communication requirements that are difficult to meet adopting a single communication technology. Software-Defined Networking and network virtualization techniques represent two promising innovations and abstractions to improve the network management and to support scalable network control functions, flexible resource allocation, and changes in the network traffic.This paper draws a research direction towards software-defined management of heterogeneous Industry 4.0 communication networks, proposing a software-defined architecture that is able to support a multitude of diverse wired and wireless communication technologies, while meeting the requirements of diverse applications. The paper also provides an implementation roadmap, discussing how to extend the EmPOWER framework to fulfill the intended target, pointing at design challenges and solutions.

Low power wide area networks (LPWANs) are suitable for many applications that require low energy consumption, support for a high number of nodes, and large coverage range. Long range (LoRa) is one of the most successful LPWAN technologies, as it enables robust long-distance low power communications and it is proven to be effective in Internet of Things (IoT) applications, such as environmental monitoring and smart metering. LoRa is also promising for Industrial IoT scenarios, but its adoption is impaired by the relevant standardized medium access control protocol, LoRaWAN, that does not offer support to real-time data flows. For this reason, this article proposes RT-LoRa, a medium access strategy for LoRa that provides support for real-time flows, thus enabling the implementation of LoRa-based LPWAN for Industrial IoT applications. This article describes RT-LoRa, presents a simulative assessment in a realistic Industrial IoT scenario and provides some guidelines for the configuration of an RT-LoRa network.

Among the Low-Power Wide Area technologies available today, LoRa is one of the most successful, as it enables robust long-distance low-power communications in the unlicensed sub_GHz Industrial, Scientific and Medical band. A number of solution providers and network operators show much interest in this technology for Industry 4.0 applications. In addition, LoRa represent a promising candidate for boosting future Industrial Internet of Things networks and services. However, the current standardized LoRaWAN Medium Access Control (MAC) protocol over LoRa does not fully cope with the requirements of industrial networks, in particular as far as the scheduling of real-time data flow is concerned. To overcome this limitation, this paper proposes Industrial LoRa, a novel medium access strategy for LoRa that enables the implementation of industrial wireless networks for Industrial Internet of Things and Industry 4.0 applications. The paper describes the proposed MAC scheme and the advantages it provides. A simulative assessment shows the performance of the proposed approach in a realistic scenario that is compliant with the requirements of soft real-time applications in Industry 4.0.

Recently, wireless sensor networks (WSNs) are emerging in various application fields thanks to their low cost and ease of deployment. In particular, the rapid increase of critical monitoring applications encourages the study and evaluation of wireless communication protocols that can fulfill the requirements of such applications. Among the WSN standards, the IEEE 802.15.4 is very promising, as it provides critical messages with the support for prioritized channel access through the Priority Channel Access mechanism. The paper assesses the behavior of an IEEE 802.15.4 wireless sensor network implementing the Priority Channel Access mechanism in a realistic monitoring scenario, focusing on the impact on critical message transmissions. The assessments are based on OMNeT++ simulations.

Low energy consumption and low cost are some of the primary issues that have to be addressed in Industrial Wireless Sensor Networks (IWSN). Such networks are being increasingly used to acquire sensory data that need to be processed in real-time. The Bluetooth Low Energy (BLE) protocol is an attractive solution for implementing low-cost IWSN with reduced energy consumption and high flexibility. However, the current BLE standard does not provide real-time support for data packets and is limited to a star topology. This paper presents a real-time protocol for industrial wireless mesh networks that is developed on top of the BLE and overcomes these limitations. The paper describes the protocol and provides analysis and experimental results.

Technological advances in sensing technologies and wireless telecommunication devices enable novel research fields related to the management of trajectory data. As it usually happens in the data management world, the challenge after storing the data is the implementation of appropriate analytics for extracting useful knowledge. However, traditional data warehousing systems and techniques were not designed for analyzing trajectory data. Thus, in this work, we demonstrate a framework that transforms the traditional data cube model into a trajectory warehouse. As a proof-of-concept, we implemented T-WAREHOUSE, a system that incorporates all the required steps for Visual Trajectory Data Warehousing, from trajectory reconstruction and ETL processing to Visual OLAP analysis on mobility data.