Tactile Internet based Cyber-Physical Systems (TCPS) are highly sensitive to component and communication la- tencies and packet drops. Building a high performing TCPS, thus, necessitates experimenting with different hardware, algorithms, access technologies, and communication protocols. To facilitate such experiments, we have developed TCPSbed, a modular testbed for TCPS. TCPSbed facilitates the integration of different components, both real and simulated, to realize different TCPS applications and evaluate their latency and control performances. TCPSbed’s latency analyzer tool employs a novel method to isolate latencies of individual TCPS components such as the latencies contributed by actuation, sensing, algorithms, and by the network, all in an online fashion. TCPSbed’s method of analyzing stability is also novel. It involves the use of the step response analysis method, a classic control-theoretic method used for analyzing the stability of generic control systems. TCPSbed’s support for edge intelligence modules enables prediction of command and feedback signals at the network’s edge allowing TCPS applications to perform well in adverse network conditions. TCPSbed’s source-code, made available through our GitHub page TactileInternet, allows developers to extend its features and functionalities further. In this paper, we describe the architecture and implementation details of TCPSbed and demonstrate its features through several proof-of-concept experiments.@en

“Tactile internet” refers to a network that can support real-time interactions between human operators and remote cyber-physical systems as if they were near to each other. For this, the network should support ultra-low latency communication, often referred to as the 1ms challenge. However, we observe that network requirements, such as latency and band- width, of tactile internet based cyber-physical systems or Tactile Cyber-Physical Systems (TCPS) are not static: they severely fluctuate over time. Therefore, for TCPS, static provisioning of network resources is sub-optimal. For optimal utilization of network resources, we propose a mechanism to, per TCPS flow, dynamically create, destroy and switch network slices, based on the network resources needed at that time. Our solution consists of two main components. First, we develop a clustering algorithm to determine the slices and their specifications required to support a TCPS flow. Second, we leverage Software-Defined Networking (SDN) and P4-programmable switches to enable on- the-fly provisioning and switching of these slices.@en

In this paper, we consider Tactile Cyber Physical Systems (TCPS), which differ from typical CPS in that haptic sensory feedback is included. In particular, we design and implement a TCPS testbed, called TCPSbed, using well-defined components and interfaces glued together using APIs. In addition to real connections, our testbed supports the interconnection of components over an NS3-emulated network. The testbed also supports the integration of applications that mimic the behaviour of real-world embedded objects. Since controlling latency and ensuring stability is crucial for TCPS applications, the testbed includes tools for fine-grained characterization of latency and control performance. Finally, through proof-of-concept experiments with our testbed, we demonstrate TCPSbed's capabilities to facilitate TCPS research and development.

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The Tactile Internet presently constitutes a vision of an Internet over which, in addition to current communications modalities, a sense of touch can be transported. In that case, people would no longer need to be physically near the systems they operate, but could control them remotely. The main problem that needs to be solved to realize the Tactile Internet is summarized by the “1 ms challenge.” If the response time of a system is below 1 ms, the end-user will not be able to tell the difference between controlling a system locally or from another location. This paper offers a summary of the requirements for haptic communications, followed by an overview of challenges in realizing the Tactile Internet. In addition, possible solutions to these challenges are proposed and discussed. For example, the development of the fifth generation mobile communication networks will provide a good foundation upon which a Tactile Internet could be built. This paper also describes the design of a modular testbed needed for testing of a wide variety of haptic system applications.@en