In order to provide consistent low-latency communication network services, Time-Sensitive Networking (TSN) unites a set of standards for time-synchronization, flow control, enhanced reliability, and management. We design the TSNFlexTest testbed with generic commodity hardware and opensource software components to enable flexible TSN measurements. We have conducted extensive measurements to validate the TSN-FlexTest testbed and to examine TSN characteristics. The measurements provide insights into the effects of TSN configurations, such as increasing the number of synchronization messages for the Precision Time Protocol, indicating that a measurement precision of 30 ns can be achieved. The TSN measurements included extensive evaluations of the Time-aware Shaper (TAS) for sets of Tactile Internet (TI) packet traffic streams. The measurements elucidate the effects of different scheduling and shaping approaches, while revealing the need for pervasive network control that synchronizes the sending nodes with the network switches. We present the first measurements of distributed TAS with synchronized senders on a commodity hardware testbed, demonstrating the same Quality-of-Service as with dedicated wires for high-priority TI streams despite a 200 over-saturation cross traffic load. The testbed is provided as an open-source project to facilitate future TSN research.

Time-Sensitive Networking (TSN) encompasses standards to facilitate near-deterministic performance in wired networks and the integration of TSN with modern wireless systems, such as Fifth Generation (5G) systems, is intensely pursued. Consequently, TSN is examined by numerous research groups. Given the limited and costly access to TSN hardware, a reliable simulator becomes crucial. OMNeT++ is a modular simulator that can be expanded with network simulation models, such as INET, which can simulate TSN functionalities. We evaluate the accuracy of the OMNeT++ INET simulator in mirroring the physical (hardware-based) reality by comparing OMNeT++ INET simulations with measurements of two commercial TSN switches. Our evaluations encompass the generalized Precision Time Protocol (gPTP) accuracy, the Store-and-Forward (SF) and Cut-Through (CT) switching forwarding latencies, the Time Aware Shaper (TAS), and Frame Preemption (FP), including combinations of CT, TAS, and FP. We find that compared to hardware measurements, INET simulations exhibit different clock synchronization dynamics, underestimate the switching latencies, and do not support CT with FP.We enhance the alignment of INET simulations with authentic hardware behaviors by modifying INET modules. We modify the INET gPTP synchronization model and the INET simulation models for the SF and CT forwarding latencies. Also, we modify the INET simulation modules to support the combined operation of CT and FP. We demonstrate how our INET modifications, which we make publicly available, accurately simulate the behaviors of real TSN hardware.

In the early 2020s, the coronavirus pandemic brought the notion of remotely connected care to the general population across the globe. Oftentimes, the timely provisioning of access to and the implementation of affordable care are drivers behind tele-healthcare initiatives. Tele-healthcare has already garnered significant momentum in research and implementations in the years preceding the worldwide challenge of 2020, supported by the emerging capabilities of communication networks. The Tactile Internet (TI) with human-in-the-loop is one of those developments, leading to the democratization of skills and expertise that will significantly impact the long-term developments of the provisioning of care. However, significant challenges remain that require today’s communication networks to adapt to support the ultra-low latency required. The resulting latency challenge necessitates trans-disciplinary research efforts combining psychophysiological as well as technological solutions to achieve one millisecond and below round-trip times. The objective of this paper is to provide an overview of the benefits enabled by solving this network latency reduction challenge by employing state-of-the-art Time-Sensitive Networking (TSN) devices in a testbed, realizing the service differentiation required for the multi-modal human-machine interface. With completely new types of services and use cases resulting from the TI, we describe the potential impacts on remote surgery and remote rehabilitation as examples, with a focus on the future of tele-healthcare in rural settings.

Robust, reliable, and deterministic networks are essential for a variety of applications. In order to provide guaranteed communication network services, Time-Sensitive Networking (TSN) unites a set of standards for time-synchronization, flow control, enhanced reliability, and management. We design the TSN-FlexTest testbed with generic commodity hardware and open-source software components to enable flexible TSN measurements. We have conducted extensive measurements to validate the TSN-FlexTest testbed and to examine TSN characteristics. The measurements provide insights into the effects of TSN configurations, such as increasing the number of synchronization messages for the Precision Time Protocol, indicating that a measurement accuracy of 15 ns can be achieved. The TSN measurements included extensive evaluations of the Time-aware Shaper (TAS) for sets of Tactile Internet (TI) packet traffic streams. The measurements elucidate the effects of different scheduling and shaping approaches, while revealing the need for pervasive network control that synchronizes the sending nodes with the network switches. We present the first measurements of distributed TAS with synchronized senders on a commodity hardware testbed, demonstrating the same Quality-of-Service as with dedicated wires for high-priority TI streams despite a 200% over-saturation cross traffic load. The testbed is provided as an open-source project to facilitate future TSN research.