Energy-efficient Topology Control Research Articles

Energy Efficient Topology Control Protocol for Wireless Sensor Networks

One major problem in the area of Wireless Sensor Networks (WSNs) is the topology control. Topology control protocols in WSNs construct an optimized network topology structure to satisfy the application requirements, such as network connectivity and coverage. In this paper, we deal with the topology control problem by adjusting the transition radius of the sensor nodes. We produce a cluster-based topology control scheme and propose a new Energy Efficient Topology Control Protocol called EETCP. In this protocol, proper transition radius can be determined using Harmony Search (HS) algorithm. The proposed protocol dynamically adjusts transition radius of nodes (unlike some previous protocols which should select radius values among predefined values). Thus, the proposed protocol has some advantage compared to the previous protocols. EETCP has less average number of neighbors compared to the existing protocols. Also, the energy consumption in EETCP is less than other protocols and the network lifetime will be prolonged. In addition, the network connectivity in EETCP is in the acceptable level. The proposed protocol is simulated and the above advantages are demonstrated by the simulation results.

COOPERATIVE AD-HOC NETWORKS FOR ENERGY EFFICIENT IMPROVE CONNECTIVITY

Mobile ad-hoc network (MANET) has been developed to meet the increase in demand for high-speed wireless network. Wireless adhoc networks are multi-hop frameworks comprising of connections among wireless nodes in the absence of any infrastructure. Thus they normally consist of unpredicted network topologies. In MANETs nodes have the liberty to move freely in various directions. Due to limited battery power, nodes require energy efficient routing protocols to gear up their network performance. Cooperative communication plays an important role in wireless networks. This is evident from the fact that most of the present cooperative communication works are aimed at link-level physical layer issues. As a consequence, the influence of cooperative communication on network-level upper layer issues, such as topology control, routing and network capacity is unnoticed. Cooperative communication is a technology by the help of which multiple nodes transmit similar data at the same time. This increases the transmission coverage and also saves power. Earlier research work on topology control dealt with cooperative communication in the form of energy saving only and did not consider for extending the coverage. It has been noticed that cooperative communication can link disconnected networks. To overcome this problem, we have studied energy efficient topology control with cooperative communication. In this paper, it has been proposed for selection of optimum relay nodes so as to decrease the overall power consumption in the cooperative ad-hoc network.

Localized and Energy-Efficient Topology Control in Wireless Sensor Networks Using Fuzzy-Logic Control Approaches

The sensor nodes in the Wireless Sensor Networks (WSNs) are prone to failures due to many reasons, for example, running out of battery or harsh environment deployment; therefore, the WSNs are expected to be able to maintain network connectivity and tolerate certain amount of node failures. By applying fuzzy-logic approach to control the network topology, this paper aims at improving the network connectivity and fault-tolerant capability in response to node failures, while taking into account that the control approach has to be localized and energy efficient. Two fuzzy controllers are proposed in this paper: one is Learning-based Fuzzy-logic Topology Control (LFTC), of which the fuzzy controller is learnt from a training data set; another one is Rules-based Fuzzy-logic Topology Control (RFTC), of which the fuzzy controller is obtained through designing if-then rules and membership functions. Both LFTC and RFTC do not rely on location information, and they are localized. Comparing them with other three representative algorithms (LTRT, List-based, and NONE) through extensive simulations, our two proposed fuzzy controllers have been proved to be very energy efficient to achieve desired node degree and improve the network connectivity when sensor nodes run out of battery or are subject to random attacks.

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Topology control can enhance energy efficiency and prolong network lifetime for wireless sensor networks. Several studies that attempted to solve the topology control problem focused only on topology construction or maintenance. This work designs a novel distributed and reliable energy-efficient topology control (RETC) algorithm for topology construction and maintenance in real application environments. Particularly, many intermittent links and accidents may result in packet loss. A reliable topology can ensure connectivity and energy efficiency, prolonging network lifetime. Thus, in the topology construction phase, a reliable topology is generated to increase network reachable probability. In the topology maintenance phase, this work applies a novel dynamic topology maintenance scheme to balance energy consumption using a multi-level energy threshold. This topology maintenance scheme can trigger the topology construction algorithm to build a new network topology with high reachable probability when needed. Experimental results demonstrate the superiority of the RETC algorithm in terms of average energy consumption and network lifetime.

An energy-efficient topology construction algorithm for wireless sensor networks

Topology management schemes have emerged as promising approaches for prolonging the lifetime of the wireless sensor networks (WSNs). The connected dominating set (CDS) concept has also emerged as the most popular method for energy-efficient topology control in WSNs. A sparse CDS-based network topology is highly susceptible to partitioning, while a dense CDS leads to excessive energy consumption due to overlapped sensing areas. Therefore, finding an optimal-size CDS with which a good trade-off between the network lifetime and network coverage can be made is a crucial problem in CDS-based topology control. In this paper, a degree-constrained minimum-weight version of the CDS problem, seeking for the load-balanced network topology with the maximum energy, is presented to model the energy-efficient topology control problem in WSNs. A learning automata-based heuristic is proposed for finding a near optimal solution to the proxy equivalent degree-constrained minimum-weight CDS problem in WSN. A strong theorem in presented to show the convergence of the proposed algorithm. Superiority of the proposed topology control algorithm over the prominent existing methods is shown through the simulation experiments in terms of the number of active nodes (network topology size), control message overhead, residual energy level, and network lifetime.

Distributed topology control algorithm on broadcasting in wireless sensor network

Topology control can enhance energy efficiency and prolong network lifetime for wireless sensor networks. Several studies that attempted to solve the topology control problem focused only on topology construction or maintenance. This work designs a novel distributed and reliable energy-efficient topology control (RETC) algorithm for topology construction and maintenance in real application environments. Particularly, many intermittent links and accidents may result in packet loss. A reliable topology can ensure connectivity and energy efficiency, prolonging network lifetime. Thus, in the topology construction phase, a reliable topology is generated to increase network reachable probability. In the topology maintenance phase, this work applies a novel dynamic topology maintenance scheme to balance energy consumption using a multi-level energy threshold. This topology maintenance scheme can trigger the topology construction algorithm to build a new network topology with high reachable probability when needed. Experimental results demonstrate the superiority of the RETC algorithm in terms of average energy consumption and network lifetime.

An Overview of Distributed Energy-Efficient Topology Control for Wireless Ad Hoc Networks

A wireless ad hoc network is composed of several tiny and inexpensive device such as wireless sensor networks (WSNs) which have limited energy. In this network energy, efficiency is one of the most crucial requirements. Data transmitting in minimum power level is one way of maximizing energy efficiency. Thus, transmission power level of nodes should be managed in a smart way to improve energy efficiency. Topology control is one of the main algorithms used in a wireless network to decrease transmission power level while preserving network connectivity. Topology control could improve energy efficiency by reasonably tuning the transmission power level while preserving network connectivity in order to increase network capacity and lifetime. In pursuit of energy efficiency and connectivity, nodes can be selfish and are conflicting with each other. Therefore to overcome the conflict, game theory is used to construct energy efficient topology, as well as minimizing energy consumption. In this paper, the main goal and most recent energy efficient topology control algorithms in WSNs and ad hoc network are classified and studied according to their specific goals.

Distributed Energy-Efficient Topology Control Algorithm in Home M2M Networks

Because machine-to-machine (M2M) technology enables machines to communicate with each other without human intervention, it could play a big role in sensor network systems. Through wireless sensor network (WSN) gateways, various information can be collected by sensors for M2M systems. For home M2M networks, this study proposes a distributed energy-efficient topology control algorithm for both topology construction and topology maintenance. Topology control is an effective method of enhancing energy efficiency and prolonging network lifetime. During the topology construction phase, each node builds a new topology based on the best parent node. Nodes can extend the network lifetime by adjusting transmission power to control the topology. In the topology maintenance phase, each node monitors the energy status of neighbors and triggers topology construction as needed. By balancing energy consumption, topology maintenance also avoids the hot spot problem. Simulation results confirm the superior performance of the proposed algorithm for distributed energy-efficient topology control (DETC) in terms of energy efficiency and network lifetime in home M2M networks.

Energy-Efficient Topology Control in Cooperative Ad Hoc Networks

Cooperative communication (CC) exploits space diversity through allowing multiple nodes cooperatively relay signals to the receiver so that the combined signal at the receiver can be correctly decoded. Since CC can reduce the transmission power and extend the transmission coverage, it has been considered in topology control protocols [1], [2]. However, prior research on topology control with CC only focuses on maintaining the network connectivity, minimizing the transmission power of each node, whereas ignores the energy efficiency of paths in constructed topologies. This may cause inefficient routes and hurt the overall network performance in cooperative ad hoc networks. In this paper, to address this problem, we introduce a new topology control problem: energy-efficient topology control problem with cooperative communication, and propose two topology control algorithms to build cooperative energy spanners in which the energy efficiency of individual paths are guaranteed. Both proposed algorithms can be performed in distributed and localized fashion while maintaining the globally efficient paths. Simulation results confirm the nice performance of all proposed algorithms.

Energy Efficient Topology Control based on Sociological Cluster in Wireless Sensor Networks

The network topology for a wide area sensor network has to support connectivity and a prolonged lifetime for the many applications used within it. The concepts of structure and group in sociology are similar to the concept of cluster in wireless sensor networks. The clustering method is one of the preferred ways to produce a topology for reduced electrical energy consumption. We herein propose a cluster topology method based on sociological structures and concepts. The proposed sociological clustering topology (SOCT) is a method that forms a network in two phases. The first phase, which from a sociological perspective is similar to forming a state within a nation, involves using nodes with large transmission capacity to set up the global area for the cluster. The second phase, which is similar to forming a city inside the state, involves using nodes with small transmission capacity to create regional clusters inside the global cluster to provide connectivity within the network. The experimental results show that the proposed method outperforms other methods in terms of energy efficiency and network lifetime.

Energy-efficient topology control in wireless ad hoc networks with selfish nodes

In wireless ad hoc networks there is no fixed infrastructure or centralized controller to enforce cooperation between nodes. Therefore, nodes may act selfishly in running network protocols for conserving their own energy resources. In this paper, we consider the “topology control (TC) game” as the problem of creating an energy-efficient topology in wireless ad hoc networks in the presence of selfish nodes. We define a new TC game in which nodes are able to dynamically adjust their transmission power in a per-packet manner, and try to minimize their energy usage through considering both traffic load and transmission power parameters. After analyzing the problem, we propose several algorithms to find stable topologies in an environment composed of selfish nodes, using two types of global and local connectivity information. Finally, we evaluate the performance of the proposed algorithms by simulations. Our simulation results show that using appropriate local information can interestingly result in more efficient topologies than global information.

Poly: A reliable and energy efficient topology control protocol for wireless sensor networks

Energy efficiency and reliability are the two important requirements for mission-critical wireless sensor networks. In the context of sensor topology control for routing and dissemination, Connected Dominating Set (CDS) based techniques proposed in prior literature provide the most promising efficiency and reliability. In a CDS-based topology control technique, a backbone – comprising a set of highly connected nodes – is formed which allows communication between any arbitrary pair of nodes in the network. In this paper, we show that formation of a polygon in the network provides a reliable and energy-efficient topology. Based on this observation, we propose Poly, a novel topology construction protocol based on the idea of polygons. We compare the performance of Poly with three prominent CDS-based topology construction protocols namely CDS-Rule K, Energy-efficient CDS (EECDS) and A3. Our simulation results demonstrate that Poly performs consistently better in terms of message overhead and other selected metrics. We also model the reliability of Poly and compare it with other CDS-based techniques to show that it achieves better connectivity under highly dynamic network topologies.

A Cluster Head Rotating Threshold for Cognitive Radio Network

Cluster-based topology is an energy-efficient topology control method in cognitive radio networks. The cluster head node depletes energy faster than cluster member node and the rotation of cluster head node is needed to balance the energy consumption for the whole network. Aimed at the problem of unbalanced residual energy of each node caused by cluster heads and cluster members in wireless cognitive radio network, a novel algorithm named cluster head rotating threshold (CHRT) is presented. In the proposed algorithm, rotation energy threshold is estimated using cluster head real-time energy load. The simulation results show that comparing with LEACH and EDAC, CHRT can realize the more network lifetime than the others.

Some properties for the largest component of random geometric graphs with applications in sensor networks

In this paper we consider the standard Poisson Boolean model of random geometric graphs G(\( \mathcal{H}_{\lambda ,s} \); 1) in ℝd and study the properties of the order of the largest component L1(G(\( \mathcal{H}_{\lambda ,s} \); 1)). We prove that E[L1(G(\( \mathcal{H}_{\lambda ,s} \); 1))] is smooth with respect to λ, and is derivable with respect to s. Also, we give the expression of these derivatives. These studies provide some new methods for the theory of the largest component of finite random geometric graphs (not asymptotic graphs as s → ∞) in the high dimensional space (d ≥ 2). Moreover, we investigate the convergence rate of E[L1(G(\( \mathcal{H}_{\lambda ,s} \); 1))]. These results have significance for theory development of random geometric graphs and its practical application. Using our theories, we construct and solve a new optimal energy-efficient topology control model of wireless sensor networks, which has the significance of theoretical foundation and guidance for the design of network layout.

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.

An energy-efficient localized topology control algorithm for wireless ad hoc and sensor networks

Topology control plays an important role in the design of wireless ad hoc and sensor networks and has demonstrated its high capability in constructing networks with desirable characteristics such a...

Energy-efficient topology control for three-dimensional sensor networks

Topology control in sensor networks has been heavily studied recently. Different geometric topologies were proposed to be the underlying network topologies to achieve the sparseness of the communication networks or to guarantee the package delivery of specific routing methods. However, most of the proposed topology control algorithms were only applied to Two-Dimensional (2D) networks where all sensor nodes are distributed in a 2D plane. In practice, the sensor networks are often deployed in 3D space, such as sensor nodes in a forest. This paper seeks to investigate efficient topology control protocols for 3D sensor networks. In our new protocols, we extend several 2D geometric topologies to 3D case, and propose some new 3D Yao-based topologies for sensor networks. We also prove several properties (e.g. bounded degree and constant power stretch factor) for them in 3D space. The simulation results confirm our theoretical proofs for these proposed 3D topologies.

The restricted shortest-path-based topology control algorithm in wireless multihop networks

In this paper, we present an energy-efficient topology control algorithm named RLSP. The algorithm first tries to preserve the minimum-energy paths. However, when a node finds it needs a large transmission power to cover some of its logical neighbors, it uses two-hop paths to reach them instead of using single links. Simulation results show that RLSP can effectively decrease the transmission power and reduce the energy consumption when transmitting.

Energy-efficient topology control for wireless sensor networks using online battery monitoring

Abstract. This paper presents a first approach towards cooperative energy management in wireless sensor networks using online battery monitoring. Using a standard platform for wireless sensor networks, a simple concept for measuring the battery voltage on the mote with little additional hardware is shown. This is used for modelling of the battery discharge behaviour of Li-Ion batteries and deriving the remaining lifetime under given environmental conditions. As an application example this model can be incorporated into a topology control scheme for optimized network lifetime under variable environmental conditions.