Joint Acquisition Time Design and Sensor Association for Wireless Sensor Networks in Microgrids

Wireless sensor networks are used to monitor the operating status of the microgrids, which can effectively improve the stability of power supplies. The topology control is a critical issue of wireless sensor networks, which affects monitoring data transmission reliability and lifetime of wireless sensor networks. Meanwhile, the data acquisition accuracy of wireless sensor networks has a great impact on the quality of monitoring. Therefore, this paper focuses on improving wireless sensor networks data acquisition satisfaction and energy efficiency. A joint acquisition time design and sensor association optimization algorithm is proposed to prolong the lifetime of wireless sensor networks and enhance the stability of monitoring, which considers the cluster heads selection, data collection satisfaction and sensor association. First, a multi-constrained mixed-integer programming problem, which combines acquisition time design and sensor association, is formulated to maximize data acquisition satisfaction and minimize energy consumption. To solve this problem, we propose an iterative algorithm based on block coordinate descent technology. In each iteration, the acquisition time is obtained by Lagrangian duality. After that, the sensor association is modeled as a 0–1 knapsack problem, and the three different methods are proposed to solve it. Finally, the simulations are provided to demonstrate the efficiency of the algorithm proposed in this paper.

KOMUNIKASI DATA PADA SISTEM PELAPORAN KECELAKAAN PERAHU NELAYAN BERBASIS LORA

The job of being a fisherman is very risky, many factors that become the threat of work lurking a fisherman. Traditional fishermen are not facilitated with communication equipment that can support the safety of fishermen. So when something happens that can harm the fishermen, it can not be handled immediately. In this research developed a wireless communication system based on LoRa to be able to monitor fishermen working at sea by online,consisting of node devices attached to boats and gateways that function to forward data from the node device to the web server using the MQTTprotocol, so that boat data can be monitored through the thingsboard dashboard. Data monitored include the location of fishing boats ( longitude and latitude coordinates ),the slope of the fishing boat (degree of roll and pitch) and also early warning. Testing the reliability of LoRa communication in marine communication scenarios is carried out by testing the distance of data transmission, data length and data delivery speed setting / air data rate with Line of Sight (LOS) condition at Sea directly. From the results of data transmission reliability testing using the communication module LoRa E32 915T20D is able to reach the furthest distance up to 2.4 Km with the data send speed setting at 0.3 kbps with an average delivery time delay / time on air that tends to increase with the increase in the length of data sent.

Bluetooth wireless temperature and humidity detection system based on STM32

Based on STM32 MCU and HC-05 module, a wireless temperature and humidity detection system is designed. In this system, STM32 is taken as the control core, the digital temperature and humidity sensor AM2303 with low power consumption and fast response is used to collect temperature and humidity signals, and bluetooth technology is used to transmit the detected environmental information, thus completing the remote communication with the upper computer. The problem of complicated wiring of traditional wired monitoring system is solved. Through Bluetooth module, the communication between STM32 single chip microcomputer and host computer can realize the real-time detection of environmental temperature and humidity. When there is danger in the room, the mobile phone or work computer can receive warning signals in time. The experimental results show that the system has the advantages of good real-time, high data transmission reliability and good intelligence, Meanwhile, the cable is saved and the cost is reduced.

Data transmission reliability evaluation of a stochastic computer network through minimal paths with a retransmission mechanism

Multipath Transmission Control Protocol is a new networking protocol which can allow data transmission and retransmission across multiple minimal paths. It can reduce data transmission time and ensure data integrity. In computer networks, the capacity of each arc should be considered as stochastic because there are different situations such as failures, partial failures, and maintenance. This article focuses on a stochastic retransmission flow network to evaluate data transmission reliability that the data can be transmitted successfully through multiple minimal paths within transmission time threshold. We first propose an algorithm to generate all minimal capacity vectors satisfying both constraints and requirements and to obtain data transmission reliability. A numerical example and a large-scale case study of the Pan-European Research and Education Network are presented to illustrate the algorithm.

Study of Non-Normal Distribution Time Parameters Data Transmission Reliability in CAN Bus

The message transmission reliability is very important for the design of the CAN (Controller Area Network) bus system, which is related to the normal operation of the bus control system. The bus message transmission time parameters are analyzed based on the CAN bus scheduling theory. The formula is a derived by means of probability analysis based on the fourth-moment method. An example is calculated to get its message reliability and the result is contrasted with the MONTE-CARLO method simulation, and then the bus message transmission reliability can be got. It has great practical significance.

Research of Routing Protocol for Wireless Meter Reading System

To improve the data transmission reliability of wireless meter reading system, a bidirectional routing algorithm is proposed. The routing algorithm is developed to make all nodes in the network establish optimal routing and register a complete neighbor table for routing maintenance. The neighbor exchange mechanism based on Hello Packet can timely detect changes in network topology and solve the problem of nodes flexibly coming in or out of the network. Simulation and system testing have all verified the reliability and usefulness of the algorithm which can satisfy the need of wireless meter reading application.