Three-dimensional Wireless Sensor Networks Research Articles

Critical Density for Exposure-Path Prevention in Three-Dimensional Wireless Sensor Networks Using Percolation Theory

To derive the critical density for exposure-path prevention in three-dimensional wireless sensor networks (3D WSNs), a bond-percolation-based scheme is proposed, which can generate the tighter lower and upper bounds of critical density. Firstly, the exposure-path prevention problem and system models based on Gaussian distribution are introduced in this paper. Then, according to percolation theory, we present a bond-percolation model to put this problem into a 3D uniform lattice. With this model, the lower and upper bounds of critical density for 3D WSNs are derived in the light of our scheme. Extensive simulations and contrast experiments also validate our developed models and evaluate the performance of the proposed schemes. Therefore, our scheme can be applied to determine a practically reliable density and detect intruders in sensor networks.

D3D-MDS: A Distributed 3D Localization Scheme for an Irregular Wireless Sensor Network Using Multidimensional Scaling

This paper proposes a distributed localization algorithm which can be applied to an irregular three-dimensional wireless sensor network, considering the algorithm accuracy and complexity. The algorithm uses clusters to eliminate the multihop distance errors. An anchor node position optimization scheme is proposed to maximize the uniformity of each subnetwork. The proposed algorithm also employs a new three-dimensional coordinate transformation algorithm, which helps to reduce the errors introduced by coordinate integration between clusters and improves the localization precision. The simulation and performance analysis results show that the localization accuracy of the D3D-MDS algorithm increases by 49.1% compared with 3D-DV-HOP and 38.6% compared with 3D-MDS-MAP. This distributed localization scheme also demonstrates a low computational complexity compared with other centralized localization algorithms.

Improving Both Energy and Time Efficiency of Depth-Based Routing for Underwater Sensor Networks

Underwater Sensor Network (UWSN) is a representative three-dimensional wireless sensor network. Due to the unique characteristics of underwater acoustic communication, providing energy-efficient and low-latency routing protocols for UWSNs is challenging. Major challenges are water currents, limited resources, and long acoustic propagation delay. Network topology of UWSNs is dynamic and complex as sensors have always been moving with currents. Some proposed protocols adopt geographic routing to address this problem, but three-dimensional localization is hard to obtain in underwater environment. As depth-based routing protocol (DBR) uses depth information only which is much more easier to obtain, it is more practical for UWSNs. However, depth information is not enough to restrict packets to be forwarded within a particular area. Packets may be forwarded through multiple paths which might cause energy waste and increase end-to-end delay. In this paper, we introduce underwater time of arrival (ToA) ranging technique to address the problem above. To maintain all the original advantages of DBR, we make the following contributions: energy-efficient depth-based routing protocol that reduces redundancy energy cost in some blind zones; low-latency depth-based routing protocol that is able to deliver a packet through an optimal path. The proposed protocols are validated through extensive simulations.

Topology Control Algorithm considering Antenna Radiation Pattern in Three-Dimensional Wireless Sensor Networks

Topology control is a key issue of wireless sensor network to reduce energy consumption and communication collision. Topology control algorithms in three-dimensional space have been proposed by modifying existing two-dimensional algorithms. These algorithms are based on the theoretical assumption that transmission power is radiated equally to the all directions by using isotropic antenna model. However, isotropic antenna does not exist, which is hypothetical antenna to compare the real antenna performance. In the real network, dipole antenna is applied, and because of the radiation pattern, performance of topology control algorithm is degraded. We proposed local remapping algorithm to solve the problem and applied it to existing topology control algorithms. Simulation results show that our algorithm increases performance of existing algorithms and reduces power consumption.

An Adjustable Topology Control Algorithm for Three-Dimensional Wireless Sensor Networks

In three-dimensional wireless sensor networks, a topology with higher node degrees usually has many routes that consume less energy, but it increases the traffic load of the whole network. Therefore, the trade-off is between the node degree and the energy efficiency. In view of this question, this paper presents the definition and property of 3D r-neighbourhood graph, and uses the graph to balance the node degree and the energy efficiency of the whole network. This algorithm named NGTC, and it can adjust the structure of the networks to be a perfect state. Finally, the simulation results prove the advantage of this algorithm.

Virtual-coordinate-based delivery-guaranteed routing protocol in three-dimensional wireless sensor networks

Because of the wide range of applications, many geographic routing protocols have been proposed in three-dimensional 3D wireless sensor networks. However, all the methods require assistance from a global positioning system GPS, which is not always available. In this paper, we propose a method of constructing an axis-based virtual coordinate assignment in 3D wireless sensor networks ABVCap_3D that requires no GPS assistance. We also propose a routing protocol based on ABVCap_3D, which guarantees packet delivery in 3D networks. Using simulations, we evaluate the performance of ABVCap_3D routing and other well-known routing protocols, such as greedy-random-greedy routing, greedy-hull-greedy routing, and the routing based on axis-based virtual coordinate assignment in 2D wireless sensor networks ABVCap routing. Simulations show that ABVCap_3D routing requires significantly relative lower cost for guaranteeing packet delivery in comparison with ABVCap routing. Simulations also demonstrate that ABVCap_3D routing ensures a moderate ratio for routing path length to the shortest ideal path length. Copyright © 2012 John Wiley & Sons, Ltd.

Heuristic Algorithm for Minimum-Latency Data Aggregation in Three-Dimensional Wireless Sensor Networks

Heuristic Algorithm for Minimum-Latency Data Aggregation in Three-Dimensional Wireless Sensor Networks

Localized geometric topologies with bounded node degree for three-dimensional wireless sensor networks

Abstract Three-dimensional (3D) wireless sensor networks have attracted a lot of attention due to their great potential usages in both commercial and civilian applications, such as environmental data collection, pollution monitoring, space exploration, disaster prevention, and tactical surveillance. Topology control in 3D sensor networks has been studied recently, and different 3D geometric topologies were proposed to be the underlying network topologies to achieve the sparseness of the communication networks. However, most of these proposed 3D topologies cannot bound the maximum node degree, i.e., some nodes may need to maintain a large number of neighbors in the constructed topologies, which is not energy efficient and may lead to large contention. In this article, we extend several existing 3D geometric topologies to a set of new 3D topologies with bounded node degree. We provide both theoretical analysis and simulation evaluation on their power efficiency and node degree distributions. Our simulation results over random 3D sensor networks confirm nice performances of these proposed 3D topologies.

Three-Dimensional Wireless Sensor Network Localization Algorithm Based on DV-Hop

Node positioning technology in wireless sensor network plays an important role in the whole network, and a lot of scholars engage in this field. According to the background that wireless sensor network is applied in Three-Dimensional space, an improved algorithm is proposed in this paper. The algorithm makes the average distance of each hop more rational through choosing the external anchor nodes. After the achievement of the unknown nodes positioning, initial positioning location would be corrected in order to get a higher positioning accuracy. Simulation results show that the accuracy of the improved algorithm is 13% higher than the traditional DV-Hop algorithm.

Four-mobile-beacon assisted localization in three-dimensional wireless sensor networks

Localization is one of key technologies of wireless sensor networks, and the mobile beacon assisted localization method is promising. For the three-dimensional sensor networks, this paper proposes a four-mobile-beacon assisted weighted centroid localization method. The four beacons form a regular tetrahedron while traversing the region and broadcast packets including their positions simultaneously. The ordinary sensor nodes estimate their locations using weighted centroid method. It also presents Layered-Scan trajectory of mobile beacons which consists of several parallel layers of Scan. This method can localize all the sensor nodes with appropriate parameters. Two sets of simulations are performed using Matlab to compare this method with other methods and evaluate tradeoffs between localization performance and different parameters. Simulation results show that the proposed method outperforms weighted centroid and multilateration methods using single mobile beacon.

Deployment with Sampling Coverage in Three-Dimensional Wireless Sensor Networks

Node deployment is one of important questions in three-dimensional wireless sensor networks(3D WSNs) for the mountain monitoring. In this article, sampling coverage is proposed,and node deployment with sampling coverage is abstracted to mathematical spacing-filling study. The solving method is verified in two-dimensional wireless sensor networks(2D WSNs) firstly,then it is extended to 3D WSNs.Several space-filling polyhedrons are used to fill three-dimensional solid space,and volume entropy is defined to evaluate space-filling perfermance. We can use the minimum nodes to constructe 3D WSNs if choose the vertexes of truncated octahedron to set nodes. That deployment method can both achieve seamless sampling coverage and high connectivity based on computer simulation.

Three-dimensional greedy anti-void routing for wireless sensor networks

Due to the low-cost design nature of greedy-based routing algorithms, it is considered feasible to adopt this type of schemes within the three-dimensional (3D) wireless sensor networks. In the existing research work, the unreachability problem (i.e., the so-called void problem) resulting from the greedy routing algorithms has not been fully resolved, especially under the 3D environment. In this letter, a three-dimensional greedy anti-void routing (3D-GAR) protocol is proposed to solve the 3D void problem by exploiting the boundary finding technique for the unit ball graph (UBG). The proposed 3D rolling-ball UBG boundary traversal (3D-RUT) scheme is employed to guarantee the delivery of packets from the source to the destination node. The correctness proofs, protocol implementation, and performance evaluation for the proposed 3D-GAR protocol are also given in this letter.

Critical Density for Coverage and Connectivity in Three-Dimensional Wireless Sensor Networks Using Continuum Percolation

Although most of the studies on coverage and connectivity in wireless sensor networks (WSNs) considered two-dimensional (2D) settings, such networks can in reality be accurately modeled in a three-dimensional (3D) space. The concepts of continuum percolation theory best fit the problem of connectivity in WSNs to find out whether the network provides long-distance multihop communication. In this paper, we focus on percolation in coverage and connectivity in 3D WSNs. We say that the network exhibits a coverage percolation (respectively, connectivity percolation) when a giant covered region (respectively, giant connected component) almost surely spans the entire network for the first time. Because of the dependency between coverage and connectivity, the problem is not only a continuum percolation problem but also an integrated continuum percolation problem. Thus, we propose an integrated-concentric-sphere model to address coverage and connectivity in 3D WSNs in an integrated way. First, we compute the critical density lambdaC con above which coverage percolation in 3D WSNs will almost surely occur. Second, we compute the critical density lambdac con above which connectivity percolation in 3D WSNs will almost surely occur. Third, we compute the critical density lambdac cov-con above which both coverage and connectivity percolation in 3D WSNs will almost surely occur. For each of these three problems, we also compute their corresponding critical network degree. Our results can be helpful in the design of energy-efficient topology control protocols for 3D WSNs in terms of coverage and connectivity.

Sensor Position Determination with Flying Anchors in Three-Dimensional Wireless Sensor Networks

This paper presents a range-free position determination (localization) mechanism for sensors in a three-dimensional wireless sensor network based on the use of flying anchors. In the scheme, each anchor is equipped with a Global Positioning System (GPS) receiver and broadcasts its location information as it flies through the sensing space. Each sensor node in the sensing area then estimates its own location by applying basic geometry principles to the location information it receives from the flying anchors. The scheme eliminates the requirement for specific positioning hardware, avoids the need for any interaction between the individual sensor nodes, and is independent of network densities and topologies. The performance of the localization scheme is evaluated in a series of simulations performed using ns-2 software and is compared to that of the Centroid and Constraint range-free mechanisms. The simulation results demonstrate that the localization scheme outperforms both Centroid and Constraint in terms of a higher location accuracy, a reduced localization time, and a lower beacon overhead. In addition, the localization scheme is implemented on the Tmote Sky for validating the feasibility in the real environment.