On the Range Assignment in Wireless Sensor Networks for Minimizing the Coverage-Connectivity Cost

This article deals with reliable and unreliable mobile sensors having identical sensing radius r , communication radius R , provided that r ≤ R and initially randomly deployed on the plane by dropping them from an aircraft according to general random process. The sensors have to move from their initial random positions to the final destinations to provide greedy path k 1 -coverage simultaneously with k 2 -connectivity. In particular, we are interested in assigning the sensing radius r and communication radius R to minimize the time required and the energy consumption of transportation cost for sensors to provide the desired k 1 -coverage with k 2 -connectivity. We prove that for both of these optimization problems, the optimal solution is to assign the sensing radius equal to r = k 1 || E [S]||/2 and the communication radius R = k 2 || E [S]||/2, where || E [S]|| is the characteristic of general random process according to which the sensors are deployed. When r < k 1 || E [S]||/2 or R < k 2 || E [S]||/ 2, and sensors are reliable, we discover and explain the sharp increase in the time required and the energy consumption in transportation cost to ensure the desired k 1 -coverage with k 2 -connectivity.

Research on the Coverage of Ultraviolet Communication Network in the Arbitrary Polygon Area

Given that the current ultraviolet (UV) networking model is established in a regular circular area, this article studies the coverage of a UV non-line-of-sight (NLOS) communication network creatively in the arbitrary polygon area. In this paper, the UV communication model and the basic concepts of network coverage are introduced first. Then the influence parameters of the UV node communication radius are studied, and the changes of the communication radius under different work patterns are analyzed. Finally, the coverage of the square target area is simulated under different communication parameters (transmitted power, data rate and node density). The results illustrate that the smaller the transceiver elevation angles are, the better the network coverage performance is. Additionally, we numerically compare the UV network models of polygonal and circular regions, which can be used as a reference for actual networking.

ESTIMATION OF THE HEAD-END MOVEMENT SPEED IN A HETEROGENEOUS WIRELESS SENSOR NETWORK WITH MOBILE HEAD-ENDS

Рассматривается гетерогенная сенсорная сеть, построенная с применением различных технологий. Для сбора данных в сети используются гетерогенные подвижные головные узлы (ПГУ). Предлагается модель сети и метод, позволяющий выбрать оптимальную скорость движения ПГУ с учетом радиуса связи и времени, необходимого для передачи данных от сенсорного узла. Приведены выражения для оценки оптимальной скорости движения ПГУ как для каждого из типов узлов, так и для гетерогенной сети в целом. Получены результаты, позволяющие выбирать параметры движения ПГУ и оценивать качество обслуживания. The paper deals with a heterogeneous sensor network built using various technologies. Heterogeneous mobile head-ends are used to collect data in the network. The paper proposes a network model and a method that allows you to choose the optimal speed of movement of the head-ends, taking into the communication radius and the time required for data transmission from the sensor node. Expressions are obtained for estimating the optimal speed of movement of the head-ends both for each of the types of nodes and for a heterogeneous network as a whole. The results allowing us to choose the parameters of movement of the mobile head-ends and assess the quality of service are obtained.

Pre-Vaccination and Quarantine Approach for Defense Against Worms Propagation of Malicious Objects in Wireless Sensor Networks

Network security poses a challenge to wireless sensor networks (WSNs) achieving its true potential. It is hard to tackle due to operational constraints of networks. Worms have become an emergent threat to the wireless networks. The spread of worms in the network is epidemic in nature. This article proposes a novel mathematical model with pre-vaccination and quarantine for study of worm propagation dynamics in WSN that is based on epidemic model. Further, the authors have devised an expression to determine threshold communication radius and node density. The objective of this proposed model is to study the propagation dynamics of worms in wireless sensor networks. Through the model, investigate the stability condition of networks in the presence of malicious codes. The experimental studies indicate that the proposed model outperforms in terms of security and energy efficiency over other existing models. It is a leap toward worm-controlling mechanisms in sensor networks. Finally, the control mechanism and performance of the proposed model is validated through extensive simulation results.

On Connectivity and Energy Efficiency for Sleeping-Schedule-Based Wireless Sensor Networks

Based on the connectivity and energy consumption problems in wireless sensor networks, this paper proposes a kind of new network algorithm called the connectivity and energy efficiency (CEE) algorithm to guarantee the connectivity and connectivity probability, and also to reduce the network energy consumption as much as possible. Under the premise that all sensors can communicate with each other in a specific communication radius, we obtained the relationship among the connectivity, the number of sensor nodes, and the communication radius because of the theory of probability and statistics. The innovation of the paper is to maximize the network connectivity and connectivity probability, by choosing which types of sleeping nodes to wake up. According to the node’s residual energy and the relative value of distance, the algorithm reduces the energy consumption of the whole network as much as possible, and wakes up the number of neighbor nodes as little as possible, to improve the service life of the whole network. Simulation results show that this algorithm combines the connectivity and the energy efficiency, provides a useful reference value for the normal operation of the sensors networks.

A New Distance Vector-Hop Localization Algorithm Based on Half-Measure Weighted Centroid

Considering the defects of the Distance Vector-Hop (DV-Hop) localization algorithm making errors and having error accumulation in wireless sensor network (WSN), we proposed a new DV-Hop localization algorithm based on half-measure weighted centroid. This algorithm followed the two-dimensional position distribution, designed the minimum communication radius, and formed a reasonable network connectivity firstly. Then, the algorithm corrected the distance between the beacon node and its neighbour node to form a more accurate jump distance so that the shortest path can be optimized. Finally, we theorized the proposed localization algorithm and verified it in simulation experiments, including same communication radius, different communication radii, and different node densities in same communication radius, and have compared the localization error and localization accuracy, respectively, between the proposed algorithm and the DV-Hop localization algorithm. The experiment’s result shows that the proposed localization algorithm have reduced the localization’s average error and improved the localization’s accuracy.

Leader-follower multi-agent flocking with bounded missing data and random communication radius

In this paper, the leader-follower Cucker–Smale flocking system with bounded missing data and random communication radius is studied. The communication network is determined by the stochastic distance radii between agents. The process by which data are lost in the communication network is independent and identically distributed. The goal of this paper is to determine a lower bound on the probability that the agents asymptotically achieve a flocking behaviour, i.e. the relative velocities between the leader agent and other agents asymptotically vanish and the relative positions converge. Finally, a numerical simulation example is provided to illustrate the obtained results.