Time‑ and Mission‑Critical Communication in Low‑Power Wireless Networks

This project will investigate and propose more reliable channel quality indicators and better coexistence mechanisms. The long-term vision of the project is that wireless communication should be as reliable and predictable as wired.

Abstract

The modern solutions in industrial wireless communication are currently unable to fulfil the expectations of process automation. The underlying reason is the lack of resilient communication protocols that are able to seamlessly recover from communication outages. Industrial Wireless Sensor Networks (IWSN) are typically expected to maintain a 99.999% (the so-called "five-nines") reliability and delays at most equal to sensor refresh rates, which can be as low as tens of milliseconds. Process automation functionalities served by the IWSN communication range from process monitoring and closed-loop control to mission-critical applications, such as interlocking. Every blackout in IWSN communication leaves the industrial process unattended, which may lead to serious consequences, such as damage of material assets, the environment and even human safety risks. The protocol design is additionally hindered by the dynamics of industrial environments, caused by the changes in the physical layout of the environment, as well as spurious electromagnetic emissions and interference from other wireless systems. Being a challenging area still in its infancy, the IWSN technology has received significant attention in the wireless sensor community. However, the main inhibitors of research efforts are the inability to understand the distinctive features of IWSN with respect to the classical WSNs, and the effects of industrial environments on wireless propagation. Another critical issue in IWSN communication is the perception of link quality. The IEEE 802.15.4 standard stipulates that every compliant device shall provide two hardware-based channel quality indicators for every received packet: Received Signal Strength (RSS) and Link Quality Indicator (LQI). This project will investigate and propose more reliable channel quality indicators and better coexistence mechanisms.

Objectives

The overall long-term vision of the project is that wireless communication should be as reliable and predictable as wired communication. Because the main problem today with real-time communication over wireless links for industrial applications is exactly this; to offer reliability and predictability. Most systems origin from consumer market and are designed for best effort communication. However, several industrial applications need deterministic communication and using a best effort approach will cause fatale problems for many applications, such as safety and fast closed-loop control, since hard deadlines will be missed. The following research questions will be addressed in this project:

• How to improve reliability over wireless links with presence of external interference?
• How to incorporate emergency alarms?
• How to guarantee deterministic networking over Internet-of-Things?

Partner companies

This project aims to address some very challenging problems both from an industrial and scientific perspective. The project consists of three partners who represent different parts in the value chain. Mid Sweden University is the academic partner that has long experience of research in industrial wireless sensor networks, communication systems, and distributed systems. The University will lead the project and the project manager is experienced in leading complex projects that targets fundamental research.

ABB Corporate Research is a world leading system provider in industrial automation and will contribute with expertise in areas such as real-time communication, distributed control systems, and implementation issues. The company will also give input to requirements for existing and future applications based on wireless communication. For ABB, this project is important for future development of their wireless product portfolio targeting new applications such as wireless control, but it is also important for the ongoing standardization efforts. Another aspect of ABB’s participation in this project is the access to good students, both on MSc and PhD level, which could potentially be recruited to the company.

Analog Devices is a world leading company in signal processing and IC components and they will provide with expertise in these areas. Furthermore, Analog Devices will provide the project with WSN chips that will be used in different industrial test and proof-of-concept demonstrations. New applications within the industrial automation put new requirements on Analog Devices’ products and this project will be important for the company in that they will receive in-depth knowledge about requirements and latest advances in IWSN technology. Another important aspect for Analog Devices to participate in this project is to get access to good students, both on MSc and PhD level, which could potentially be recruited to the company.