Going wireless is one of the key industrial trends, which assists the emergence of new manufacturing and maintenance processes by reducing the complexity and cost of physical equipment. However, the adoption of Wireless Sensor Networks (WSNs) in production environments is limited due to the strict Quality of Service (QoS) requirements of industrial applications. In particular, Wireless Avionics Intra-Communication (WAIC) systems operating in 4.3 GHz band are designed for intra-aircraft use cases with considerable restrictions on the transmission power of sensors, which results in multi-hop topologies, complicating a guaranteed QoS. The Internet Engineering Task Force (IETF) has developed the protocol stack IPv6 over the Time Slotted Channel Hopping (TSCH) mode of IEEE 802.15.4 (6TiSCH) based on the IEEE 802.15.4 Standard for Low-Rate Wireless Networks, which combines the TSCH reliability with ubiquitous IPv6 connectivity and with the robust Routing Protocol for Low-Power and Lossy Networks (RPL). The Scheduling Function (SF) is a core IPv6 over the TSCH mode of IEEE 802.15.4 (6TiSCH) component, but the specification of the SF is an open research topic: numerous scientific articles investigated how QoS for a wide range of applications can be met by developing specialized SFs. However, no full-scale information exchange between the layers of the 6TiSCH stack was considered to optimize the SFs and to improve the network performance. In this work, we propose a novel solution named 6TiSCH-CLX to satisfy demanding QoS requirements using cross-layer communication. It is an extension of the 6TiSCH framework at the network and Medium Access Control (MAC) layers, addressing latency and reliability challenges agnostic of the physical layer. 6TiSCH-CLX is evaluated both analytically and in simulations for several safety-critical avionic intra-communication use cases in WAIC. Preliminary results indicate considerable improvements to latency, while maintaining almost 100% Packet Delivery Ratio (PDR) without retransmissions and they highlight the capability of the cross-layer approach compared to existing solutions.

Wireless communication offers significant advantages in terms of flexibility, coverage and maintenance compared to wired solutions and is being actively deployed in the industry. IEEE 802.15.4 standardizes the Physical and the Medium Access Control (MAC) layer for Low Power and Lossy Networks (LLNs) and features Timeslotted Channel Hopping (TSCH) for reliable, low-latency communication with scheduling capabilities. Multiple scheduling schemes were proposed to address Quality of Service (QoS) in challenging scenarios. However, most of them are evaluated through simulations and experiments, which are often time-consuming and may be difficult to reproduce. Analytical modeling of TSCH performance is lacking, as only one-hop communication with simplified traffic patterns is considered in state-of-the-art. This work proposes a new framework based on queuing theory and combinatorics to evaluate end-to-end delays in multihop TSCH networks of arbitrary topology, traffic and link conditions. The framework is validated in simulations using OMNeT++ and shows below 6% root-mean-square error (RMSE), providing quick and reliable latency estimation tool to support decision-making and enable formalized comparison of existing scheduling solutions.

The concept of cellular energy systems of the German Association for Electrical, Electronic & Information Technologies (VDE) proposes sector coupled energy networks for energy transition based on cellular structures. Its decentralized control approach radically differs from that of existing networks. Deeply integrated information and communications technologies (ICT) open opportunities for increased resilience and optimizations. The exploration of this concept requires a comprehensive simulation tool. In this paper, we investigate simulation techniques for cellular energy systems and present a concept based on co-simulation. We combine simulation tools developed for different domains. A classical tool for studying physical aspects of energy systems (Modelica, TransiEnt library) is fused with a state-of-the-art communication networks simulator (OMNeT++) via the standardized functional mock-up interface (FMI). New components, such as cell managers, aggregators, and markets, are integrated via remote procedure calls. A special feature of our concept is that the communication simulator coordinates the co-simulation as a master and integrates other components via a proxy concept. Model consistency across different domains is achieved by a common description of the energy system. Evaluation proves the feasibility of the concept and shows simulation speeds about 20 times faster than real time for a cell with 111 households.

New applications emerge for Wireless Sensor Networks (WSNs), e.g., monitoring and surveillance, producing bursty traffic which greatly impacts communication network performance. The latter can be evaluated through simulations or experiments, both of which are more time-consuming and costly than analytical models. Reliable communication in WSNs is achievable through IEEE 802.15.4 Timeslotted Channel Hopping (TSCH). Accurately evaluating its performance under bursty traffic is critical to plan future networks. This letter proposes a framework for modeling the impact of bursty traffic on end-to-end delays in TSCH networks, using queuing theory and Markov chains. Simulations in OMNeT++ validate framework accuracy with <1% normalized Root Mean Squared Error (RMSE).