Dynamic Wireless QoS Analysis for Real-Time Control in URLLC

Lim

et al. 2021

Sensors

In this study, two-photon laser scanning microscopy (TPLSM) based on the internet of things (IoT) is proposed as a remote research equipment sharing system, which enables the remote sharing economy. IoT modules, where data are transmitted to and received from the remote users in the web service via IoT, instead of a data acquisition (DAQ) system embedded in the conventional TPLSM, are installed in the IoT-based TPLSM (IoT-TPLSM). The performance for each IoT module is evaluated independently, and it is confirmed that it works well even in a personal computer-free environment. In addition, a message queuing telemetry transport (MQTT) protocol is applied to the DAQ interface in the web service, and a graphic user interface for enabling the remote users to operate IoT-TPLSM remotely is also designed and implemented. For the image acquisition demonstration, the stained cellular images and the autofluorescent tissue images are obtained in IoT-TPLSM. Lastly, it is confirmed that the comparable performance is provided with the conventional TPLSM by evaluating the imaging conditions and qualities of the three-dimensional image stacks processed in IoT-TPLSM.

Section: Discussionmentioning

confidence: 99%

IoT-Based Research Equipment Sharing System for Remotely Controlled Two-Photon Laser Scanning Microscopy

Lim

et al. 2021

Sensors

“…Each node can access both cellular channels (in which the node is the PU) and cognitive channels (in which the node is the SU). D2D enables direct communication between two nodes without traversing the base station (BS), particularly the macrocell (MC) BS (or a central controller) that has the largest coverage in 5G networks [5] using D2D communication, a node can access both cellular and cognitive channels; as a result, it improves spectrum efficiency and QoS [6,7].…”

Section: Introductionmentioning

confidence: 99%

An Experimental Study on D2D Route Selection Mechanism in 5G Scenarios

et al. 2021

This paper demonstrates a route selection mechanism on a testbed with heterogeneous device-to-device (D2D) wireless communication for a 5G network scenario. The source node receives information about the primary users’ (PUs’) (or licensed users’) activities and available routes from the macrocell base station (or a central controller) and makes a decision to select a multihop route to the destination node. The source node from small cells can either choose: (a) a route with direct communication with the macrocell base station to improve the route performance; or (b) a route with D2D communication among nodes in the small cells to offload traffic from the macrocell to improve spectrum efficiency. The selected D2D route has the least PUs’ activities. The route selection mechanism is investigated on our testbed that helps to improve the accuracy of network performance measurement. In traditional testbeds, each node (e.g., Universal Software Radio Peripheral (USRP) that serves as the front-end communication block) is connected to a single processing unit (e.g., a personal computer) via a switch using cables. In our testbed, each USRP node is connected to a separate processing unit, i.e., raspberry Pi3 B+ (or RP3), which offers three main advantages: (a) control messages and data packets are exchanged via the wireless medium; (b) separate processing units make decisions in a distributed and heterogeneous manner; and (c) the nodes are placed further apart from one another. Therefore, in the investigation of our route selection scheme, the response delay of control message exchange and the packet loss caused by the operating environment (e.g., ambient noise) are implied in our end-to-end delay and packet delivery ratio measurement. Our results show an increase of end-to-end delay and a decrease of packet delivery ratio due to the transmission of control messages and data packets in the wireless medium in the presence of the dynamic PUs’ activities. Furthermore, D2D communication can offload 25% to 75% traffic from macrocell base station to small cells.

“…In this paper, our motivation is to obtain a communicationcontrol co-design scheme to reduce the usage of the extremely high QoS in URLLC, where we intend to use dynamic QoS allocation, i.e., both extremely high QoS and relatively low QoS, to serve the control process. In [20] and [21], we have shown that the hybrid high and low communication QoS can be adopted in wireless control systems. In this paper, we further discuss our dynamic QoS allocation method by communication-control co-design in details.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Communication QoS Design for Real-Time Wireless Control Systems

et al. 2020

Self Cite

In the coming fifth-generation (5G) cellular networks, ultra-reliable and low-latency communication (URLL-C) is treated as an indispensable service to enable real-time wireless control systems. However, the extremely high qualityof-service (QoS) in URLLC causes significant wireless resource consumption. Moreover, to obtain good control performance may not always require extremely high communication QoS. In this paper, we propose a communication-control co-design scheme to reduce wireless resource consumption, where we obtain a dynamic communication QoS design method to reduce the energy consumption by jointly using extremely high QoS and a relatively low QoS. In this scheme, we first explore the control process served by different communication QoS levels and find that the whole control process can be divided into two phases, where different QoS levels have their advantages in different phases. Then, we obtain a threshold to decide when the extremely high QoS or relatively low QoS should be provided by communications. Simulation results demonstrate that our method can effectively reduce communication energy consumption while maintaining good control performance.