On 10 September 2024, NIST leaders Dr. David Wollman, Deputy Chief of NIST’s Smart Connected System Division, and Dr. Thomas Roth, Leader of NIST’s IoT Devices and Infrastructure Group, gave an overview of NIST’s Cyber-Physical Systems (CPS) and Internet of Things (IoT) program at the Department of Energy’s (DOE’s) Executive Lunch and Learn. This session was part of a long-standing presentation series organized and produced by DOE’s Cybersecurity Awareness and Training (CSAT) team in the DOE Office of the Chief Information Officer (OCIO).
Dr. Wollman discussed the varying terminology used to describe smart connected systems, including CPS, IoT, Operational Technology (OT), Industry 4.0, Cyber-Physical Socio-Technical Systems, and Computing-Enabled Networked Physical Systems, and he advocated for the continued infusion of human-centered engineering concepts into CPS and IoT development. Referencing NIST Special Publication 1900-202 Cyber-Physical Systems and Internet of Things, he explained that CPS and IoT concepts have largely converged, and that CPS and IoT consist of interacting logical, physical, transducing, and human components that are co-engineered to achieve desired function. He also provided an overview of the NIST CPS Framework (NIST Special Publications 1500-201 -202 and -203) and its methodology for identifying and addressing stakeholder concerns, collected into groups of concerns called aspects, throughout any systems-engineering processes, described in modes of thinking called facets. One of the aspects, trustworthiness, was of particular importance to the audience since it included security and resilience, in addition to privacy, reliability, and safety. Dr. Wollman then described how the program’s foundational efforts have supported NIST’s ongoing work in OT and IoT cybersecurity.
Dr. Roth discussed the application of cybersecurity to CPS and IoT systems using the NIST Automated Vehicles Program as a use case. Due to the immense city-wide scale of these systems, and the potential for harm to humans if they fail, assurance cases of CPS/IoT rely heavily on simulation. Two simulation techniques commonly leveraged in NIST research are co-simulation and digital twins. Co-simulation is the integration of multiple simulation environments to create higher-fidelity models, such as combining a road traffic simulation with a wildfire spread simulation to model traffic congestion during evacuations caused by natural disasters. Digital twins are simulation models that are created and updated over their lifecycle with real-world data to create a virtual ‘clone’ of a real CPS/IoT system. For the wildfire evacuation example, a digital twin could be a road traffic model based on real-world traffic data from a specific city or region. NIST uses both techniques in its automated vehicles (AVs) program to explore how AVs will behave when deployed on roads, including their resilience against potential cybersecurity attacks.
NIST has released its latest software version of SimPROCESD v0.3.0, or Simulated-Production Resource for Operations and Conditions Evaluation to Support Decision-Making. SimPROCESD is used to model discrete manufacturing systems such as the production and assembly of finished products like vehicles, consumer electronics, and consumer goods. SimPROCESD is free, available for download, and has instructions for getting started.
NIST developed SimPROCESD to help users rapidly evaluate alternative manufacturing configurations, production programs, and maintenance policies. Within a manufacturing system, SimPROCESD can simulate:
Parts to represent the goods being produced.
Sources for introducing parts to the system.
Sinks for receiving and storing parts that exit the manufacturing stream.
PartFlowControllers, which are objects that represent downstream routing of received parts.
PartHandlers, which extend PartFlowController’s abilities by retaining parts from upstream for a specific time period before passing them downstream.
Buffers, a specific type of PartHandler that passes down stored parts when possible and has an optional minimum storage time.
PartProcessors, which extend PartHandler’s abilities by processing received parts, and allowing to be shutdown for maintenance work.
Probes & Sensors, including the ability to take periodic or on-demand readings and record the simulated data, which is accessible during and after the simulation.
Maintainers, used to conduct maintenance on PartProcessor machines according to user-specified policies.
The latest SimPROCESD is an improvement over the 2023 release and now enables users to:
Model groups of device objects that can be reused in multiple instances of a multi-stage manufacturing flow (also known as reentrant flows).
Model limited resource designation & tracking with the new ResourceManager object.
Have more flexibility in customizing manufacturing objects with the newly restructured base device types: PartProcessor, PartHandler, and PartFlowController.
Simulate model iterations while utilizing multiple CPU cores (max of 1/iteration).
In addition to these new improvements, the latest SimPROCESD release includes new examples for implementing reentrant flows, shared resource management, and using multiple CPU cores to rerun simulations.
The NIST Industrial Wireless Systems team held an industry meeting on September 12, 2024, to facilitate discussions on “Advanced Technologies and Use Cases for High-performance Industrial Wireless Systems.” The NIST Industrial Wireless Systems Technical Interest Group (IWSTIG) meeting was organized and led by NIST’s Rick Candell and Kang Lee with support from Mohamed Hany and Karl Montgomery. Google’s Preston Marshall provided an engaging keynote on “5G and Beyond for Advanced Manufacturing and Warehousing Environments.” Other presentations centered on functional safety over deterministic wireless networks, AI-assisted channel estimation and prediction, 5G open-source initiatives, standardization of wireless network performance evaluation though IEEE P3388, and the future of industrial wireless for mission critical applications. Presenters included Zhibo Pang (ABB), Stefano Scanzio (CNR Italy), Pablo Angueira (University of the Basque Country), Ted Schnaare (Emerson Automation), Paul Vineyard (OLTC), Nicolas Tondre (Firecell), Mohamed Hany (NIST), and Rick Candell (NIST).
Wireless communications technology is emerging as an enabling technology for facilitating industrial communications by providing flexibility and economical installation costs compared to wired solutions. However, concerns exist about reliability and latency in industrial wireless networks. Deployments of wireless networks in industrial environments have experienced varying degrees of success. These include industrial wireless technologies based upon IEEE 802.15.4 (Low-Rate Wireless Sensor Networks), IEEE 802.11 (Wi-Fi), IEEE 802.15.1 (BT/BLE), 3GPP (4/5/6G), and many others. Industrial wireless environments can be harsh, demanding, and quite different from homes and offices. Moreover, mission-critical industrial applications are distinctive, where data loss and retransmissions cannot be tolerated. To make wireless a reality in factory and industrial environments, it is essential to analyze various industrial scenarios, including the physical environments, the communication requirements, and any possible wireless aggressors.
This industry meeting provided an opportunity for members of the NIST Industrial Wireless Systems Technical Interest Group to develop a deeper understanding of current trends and concerns pertaining to industrial wireless communications, measurement techniques and standardization with one of the principal goals being to support industry with economical, high-volume deployments. To subscribe to the NIST IWSTIG mailing list, send mail to iwstig+subscribe@list.nist.gov.
NIST Industrial Wireless Systems team member Mohamed Kashef (Hany) presented on real-time and mission-critical wireless systems in an invited panel session at AraFest’24 on August 27, 2024. Dr. Hany provided opening remarks on “Industrial Wireless Systems and the IEEE P3388 Standard for Wireless Systems Performance Assessment,” focusing on the importance of understanding wireless aggressors in industrial settings and how to evaluate wireless performance in operational scenarios. Hany covered the IEEE P3388 standard for performance assessment of industrial wireless systems and gave an overview of the NIST industrial wireless system laboratory capabilities to support the standard development. Hany further contributed to the panel discussion by describing the challenges for wireless deployment in real-time and mission-critical systems in practice including the need for channel and operational system models, the co-design of wireless protocols and control applications, and specifying the practical requirements of various use cases.
Karl Montgomery and Rick Candell of the NIST Industrial Wireless Team have produced a report titled “A Characterization of OFDMA Uplink Activation for Industrial Applications” (NIST IR 8506) which presents findings on Orthogonal Frequency-Division Multiple Access (OFDMA) operations based on the IEEE 802.11ax (Wi-Fi 6) specification. OFDMA improves network performance by allowing for simultaneous data transmission from multiple devices. The report details the experimental methodologies and findings used to determine OFDMA triggering conditions. The work examined the conditions required for OFDMA uplink trigger frames sent by commercial access points (APs). In the devices tested, OFDMA was activated when two or more stations transmitted over 100 packets per second (pps), regardless of packet size. This finding was previously not publicly available, as the trigger conditions for OFDMA are not specified in the IEEE 802.11ax (Wi-Fi 6) standard. This finding has led to the recommendation that future Wi-Fi versions implementing OFDMA include a tunable OFDMA trigger condition feature in support of low latency industrial applications. These recommended modifications to future OFDMA Wi-Fi implementations were recommended to reduce latency for time-critical applications.
Nathan Wei, a NIST SURF student working with the industrial wireless team under the mentorship of Karl Montgomery, added a new wireless communications capability to the existing Industrial Wireless Testbed’s Collaborative Robotic use case. Support for the User Datagram Protocol (UDP) was implemented for the positional update stream, replacing the previously implemented Transmission Control Protocol (TCP). For his work, Nathan was selected as a Plenary speaker in the SURF Colloquium, and his talk was titled, “Supporting UDP Communications for a Real-Time Control Robotic Application.” In his presentation, Nathan described differences in transport protocols and showed the resulting impact that the UDP implementation made for wireless communications with various interfering traffic loads. The physical and network measurements revealed that the 'send and forget' transmission protocol (UDP) was better suited for high-update rate applications where data rapidly becomes “stale.” In addition to this work, Nathan implemented a new wireless “co-design” feedback control feature developed by NIST’s Rick Candell and Karl Montgomery to provide adaptive error feedback compensation between the leader and follower robots. With this change, the robots now reduce their synchronization error by an order of magnitude improvement. Wireless “co-design” plays a crucial role in using wireless communications as a primary mode of communications in Operational Technology in which both traditional and AI-assisted control may be used.
