Round Trip Time of Network Cables: A Comparative Analysis

This experimental research study was conducted to compare the round-trip time of commonly used network cables among Internet Cafés in Estancia, Iloilo. Specifically, it focused on the brand names of network cable and the distance of cable from the access point to remote terminal. This study attempted to determine whether there was no significant difference among cables which differs from their brand names and distances. The research instrument used in gathering the data was the researchers-made survey form which was submitted to the three panels of experts for face validation before the instrument was given to Internet Cafe Owner’s and computer stores in the Municipality of Estancia. The statistical tools used were the frequency counts, percentages, rank, arithmetic mean, and chi-square. The results revealed that there were significant differences in the round-trip time between brands of network cables when tested at long and short distances from access point to remote terminal. It was found out that there was no significant difference in the overall round-trip time between brands of network cables when tested at long, medium, and short distances from access point to remote terminal. This simply showed that Internet Cafés can make use of any brand available in the market because they perform the same. However, among the three brands being tested it was also revealed that the best brand of network cables in terms of round-trip time was the Belden.

Formation Control of Dual Auto Guided Vehicles Based on Compensation Method in 5G Networks

With commercial application of 5G networks, many researchers have started paying attention to real-time control in 5G networks. This paper focuses on dual auto guided vehicles collaborative transport scenarios and designs a formation control system in current commercial 5G networks. Firstly, the structure of the 5G network researched in this paper is introduced. Then the round-trip time of 5G networks is measured and analyzed. The result shows that although the 5G round-trip time has randomness, it is mainly concentrated in 19 ± 3 ms, and the jitter mainly in 0 ± 3 ms. The Kalman filter is applied to estimate the transmission delay and experiment result shows the effectiveness of the estimation. Furthermore, the total delay including transmission delay and execution delay in control system is discussed. After establishing the AGV kinematic and formation model, complete control system based on compensation method is proposed. Finally, an experiment is carried out. Compared to the result without formation control, maximum distance error is reduced by 82.61% on average, while maximum angle error 45.91% on average. The result shows the effectiveness of the control system in formation maintaining in 5G network.

Implementation of MQTT Protocol in Health Care Based on IoT Systems: A Study

Internet of things IoT systems have become one of the most promising technologies in all fields. Data transmission is one of the important aspects, and the tendency to messaging protocols is an important aspect of IoT systems. One of these most important protocols is MQTT. This protocol depends on the Publish/Subscribe model, and it is a lightweight protocol. Reliability, simplicity, quality of service levels, and being Resource-constrained make MQTT common in the IoT industry. This paper designed an IoT device that consists of the sensor MLX 90614 non-contact IR Temperature connected to a development board (Node MCU ESP8266). A person's temperature is one of the important vital signs. This system measures human temperature values and transmits the measured values to the Mosquitto broker by using the MQTT protocol in real-time. The technology used is Wi-Fi. The person or the doctor can read the patient’s temperature remotely through a program (Flutter Android Client) representing the subscriber. Also, MQTT protocol control packets of the system were analyzed using Wireshark. The three levels of QoS were used in subscriber clients to compare the throughput. The results indicate that QoS2 is more reliable and offers more throughput but more delay. The results also show that the average round trip time (RTT) of the MQTT protocol is five milliseconds which means optimal performance for IoT applications.

Combining Indoor Positioning Using Wi-Fi Round Trip Time with Dust Measurement in the Field of Occupational Health

Monitoring of personal exposure to hazardous substances has garnered increasing attention over the past few years. However, no straightforward and exact indoor positioning technique has been available until the recent discovery of Wi-Fi round trip time (Wi-Fi RTT). In this study, we investigated the possibility of using a combination of Wi-Fi RTT for indoor positioning and a wearable particle monitor (WPM) to observe dust concentration during walking in a simulated factory. Ultrasonic humidifiers were used to spray sodium chloride solution inside the factory. The measurements were recorded three times on different routes (Experiments A, B, and C). The error percentages, i.e., measurements that were outside the expected measurement area, were 7% (49 s/700 s) in Experiment A, 2.3% (15 s/660 s) in Experiment B, and 7.8% (50 s/645 s) in Experiment C. The dust measurements were also recorded without any obstruction. A heat map was created based on the results from both measured values. Wi-Fi RTT proved useful for computing the indoor position with high accuracy, suggesting the applicability of the proposed methodology for occupational health monitoring.

APTM: A Model for Pervasive Traceability of Agrochemicals

As the world population increases and the need for food monoculture farms are using more and more agrochemicals, there is also an increase in the possibility of theft, misuse, environmental damage, piracy of products, and health problems. This article addresses these issues by introducing the agrochemical pervasive traceability model (APTM), which integrates machine learning, sensors, microcontrollers, gamification, and two blockchains. It contributes in two dimensions: (I) the study of the environmental, product piracy and regulatory of agrochemical control; (II) the technological dimension: application of an adequate set of sensors collecting multiple data; modeling and implementation of a system via machine learning for analyzing and predicting the behavior and use of agrochemicals; development of a scoring system via gamification for reverse use of agrochemicals; and presenting a record of transactions in a consortium of two blockchains, simultaneously. Its main advantage is to be a flexible, adaptable, and expansive model. Results indicated that the model has positive aspects, from detecting the agrochemical, its handling, and disposal, recording of transactions, and data visualization along the reverse supply chain. This study obtained a round trip time of 0.510 ms on average; data transfers between layer one and its persistence in the database were between 4 to 5 s. Thus, blockchain nodes consumed only 34 to 38% of CPU and recorded transactions between 2 to 4 s. These results point to a horizon of applicability in real situations within agricultural farms.

Fundamental and Harmonic Self Mode-locking in Mid IR Heavily Doped Fiber Lasers

Harmonic self mode-locking effects are observed in heavily doped fiber lasers operating near 3 μm. The temporal profiles for the output of an Er-ZBLAN fiber laser operating at ~2.7 μm and an Ho, Pr-ZBLAN fiber laser operating at ~2.87 μm are reported. Stable second harmonic mode-locking is observed in the Er-ZBLAN fiber laser under 970nm pumping for an Er concentration of 50000 ppm, while unstable harmonic mode-locking of order of between 1-1/7 times the round cavity round trip time was observed for the higher concentration of 80000 ppm and for all pump powers. Unstable harmonic mode-locking is observed in the Ho, Pr-ZBLAN fiber laser when pumped at 1064nm, for fiber lengths up to 13m and for all pump powers. The experimental mode-locked pulse train periods are found to be consistent with theoretical analysis. The origin and properties of harmonic self mode-locking in heavily doped ZBLAN fiber lasers operated near 3 μm are discussed. Keywords: Er-ZBLAN fiber laser, Ho, Pr-ZBLAN fiber laser, Self mode-locking, Harmonic self mode-locking. PACS: Fiber lasers, 42.55.Wd, Mode locking, 42.60.Fc.