Performance analysis of TDMA-based Wireless Network for Safety-critical Avionics

The opportunities and challenges for using wireless interconnects for safety-critical avionics have been discussed in our previous work.A Wireless Avionics Network (WAN)has been proposed based on hybrid architecture UWB and Switched Ethernet with adequate reliability and security mechanisms to increase scalability and reduce electromagnetic susceptibility. Furthermore, a TDMA-based protocol was considered to guarantee a contention free access and enhance communication predictability. However, the use of wireless technologies may increase the communication latencies due to transmission errors, and real time constraints have to be verified. In order to deal with the worst case performance analysis of such network, an appropriate schedulability analysis based on Network Calculus formalism is presented in this paper and obtained results for a realistic case study are discussed herein

Fly-By-Wireless for Next Generation Aircraft: Challenges and Potential solutions

”Fly-By-Wireless” paradigm based on wireless connectivity in aircraft has the potential to improve efficiency and flexibility, while reducing weight, fuel consumption and maintenance costs. In this paper, first, the opportunities and challenges for wireless technologies in safety-critical avionics context are discussed. Then, the assessment of such technologies versus avionics requirements is provided in order to select the most appropriate one for a wireless aircraft application. As a result, the design of a Wireless Avionics Network based on Ultra WideBand technology is investigated, considering the issues of determinism, reliability and security

Performance optimization of a UWB-based network for safety-critical avionics

To reduce the aircraft weight and maintenance costs while guaranteeing system performance and reliability, an alternative avionic communication architecture based on Ultra Wide Band (UWB) and TDMA protocol is proposed to replace the back-up part of safety-critical avionics network. The analysis and performance optimization of such a proposal is tackled as follows. First, appropriate system modeling and timing analysis, using Network Calculus and Integer Linear Programing (ILP) approach, are provided to evaluate the end-to-end delays and verify system predictability. Then, an optimization approach to find the optimal TDMA cycle duration, which minimizes the end-to-end delays, is proposed. Finally, the efficiency of our proposal to enhance the system performance is validated through a realistic avionic case study

Timing Analysis of TDMA-based Networks using Network Calculus and Integer Linear Programming

For distributed safety-critical systems, such as avionics and automotive, shared networks represent a bottleneck for timing predictability, a key issue to fulfill certification requirements. To control interferences on such shared resources and guarantee bounded delays, the Time Division Multiple Access (TDMA) protocol is considered as one of the most interesting arbitration protocols due to its deterministic timing behavior and fault-tolerance features. This paper addresses the problem of computing the worst-case end-to-end delay bounds for traffic flows sharing a TDMA-based network using Network Calculus. First, we extend classic timing analysis to integrate the impact of non-preemptive message transmission and various service policies in end-systems, e.g., First In First Out (FIFO), Fixed Priority (FP) and Weighted Round Robin (WRR). Afterwards, the proposed models are refined using Integer Linear Programming (ILP) to obtain tighter end-to-end delay bounds. Finally, this general analysis is illustrated and validated in the case of a TDMA-based Ethernet network for I/O avionics applications. Results show the efficiency of the proposed models to provide stronger guarantees on system schedulability, compared to classic models

Airborne Wireless Sensor Networks for Airplane Monitoring System

In traditional airplane monitoring system (AMS), data sensed from strain, vibration, ultrasound of structures or temperature, and humidity in cabin environment are transmitted to central data repository via wires. However, drawbacks still exist in wired AMS such as expensive installation and maintenance, and complicated wired connections. In recent years, accumulating interest has been drawn to performing AMS via airborne wireless sensor network (AWSN) system with the advantages of flexibility, low cost, and easy deployment. In this review, we present an overview of AMS and AWSN and demonstrate the requirements of AWSN for AMS particularly. Furthermore, existing wireless hardware prototypes and network communication schemes of AWSN are investigated according to these requirements. This paper will improve the understanding of how the AWSN design under AMS acquires sensor data accurately and carries out network communication efficiently, providing insights into prognostics and health management (PHM) for AMS in future

Autonomous electrical current monitoring system for aircraft

Aircraft monitoring systems offer enhanced safety, reliability, reduced maintenance cost and improved overall flight efficiency. Advancements in wireless sensor networks (WSN) are enabling unprecedented data acquisition functionalities, but their applicability is restricted by power limitations, as batteries require replacement or recharging and wired power adds weight and detracts from the benefits of wireless technology. In this paper, an energy autonomous WSN is presented for monitoring the structural current in aircraft structures. A hybrid inductive/hall sensing concept is introduced demonstrating 0.5 A resolution, < 2% accuracy and frequency independence, for a 5 A – 100 A RMS, DC-800 Hz current and frequency range, with 35 mW active power consumption. An inductive energy harvesting power supply with magnetic flux funnelling, reactance compensation and supercapacitor storage is demonstrated to provide 0.16 mW of continuous power from the 65 μT RMS field of a 20 A RMS, 360 Hz structural current. A low-power sensor node platform with a custom multi-mode duty cycling network protocol is developed, offering cold starting network association and data acquisition/transmission functionality at 50 μW and 70 μW average power respectively. WSN level operation for 1 minute for every 8 minutes of energy harvesting is demonstrated. The proposed system offers a unique energy autonomous WSN platform for aircraft monitoring

Ethernet - a survey on its fields of application

During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal