Application of Particle Swarm Techniques in Sensor Network Configuration

A decentralized version of particle swarm optimization called the distributed particle swarm optimization (DPSO) approach is formulated and applied to the generation of sensor network configurations or topologies so that the deleterious effects of hidden nodes and asymmetric links on the performance of wireless sensor networks are minimized. Three different topology generation schemes, COMPOW, Cone-Based and the DPSO--based schemes are examined using ns-2. Simulations are executed by varying the node density and traffic rates. Results contrasting heterogeneous vs. homogeneous power reveal that an important metric for a sensor network topology may involve consideration of hidden nodes and asymmetric links, and demonstrate the effect of spatial reuse on the potency of topology generators

A Distributed Evolutionary Algorithmic Approach to the Least-Cost Connected Constrained Sub-Graph and Power Control Problem

When wireless sensors are capable of variable transmit power and are battery powered, it is important to select the appropriate transmit power level for the node. Lowering the transmit power of the sensor nodes imposes a natural clustering on the network and has been shown to improve throughput of the network. However, a common transmit power level is not appropriate for inhomogeneous networks. A possible fitness-based approach, motivated by an evolutionary optimization technique, Particle Swarm Optimization (PSO) is proposed and extended in a novel way to determine the appropriate transmit power of each sensor node. A distributed version of PSO is developed and explored using experimental fitness to achieve an approximation of least-cost connectivity

k-NEIGHLEV: a Practical Realization of Neighborhood-Based Topology Control in Ad Hoc Networks

Neighborhood-based topology control has been proven to be very effective in reducing energy consumption and increasing network capacity in ad hoc networks. In this paper, we present a practical realization of this approach that does not rely on distance estimation. Instead, the protocols presented in this paper leverage a feature typical of current wireless cards, namely that discrete power levels can be used for transmission. Ours are the first discrete-power-level protocols that do not require changing the power level on a per-packet basis. We demonstrate, through simulation, that the excellent performance of neighborhood-based topology control is maintained in this more practical setting. We also show that significant energy savings can be obtained if the power levels are optimized for topology control, rather than chosen in an ad hoc manner. Finally, we extend our approach to provide a neighborhood-based topology control protocol that is suitable for mobile networks

Topology Recoverability Prediction for Ad-Hoc Robot Networks: A Data-Driven Fault-Tolerant Approach

Faults occurring in ad-hoc robot networks may fatally perturb their topologies leading to disconnection of subsets of those networks. Optimal topology synthesis is generally resource-intensive and time-consuming to be done in real time for large ad-hoc robot networks. One should only perform topology re-computations if the probability of topology recoverability after the occurrence of any fault surpasses that of its irrecoverability. We formulate this problem as a binary classification problem. Then, we develop a two-pathway data-driven model based on Bayesian Gaussian mixture models that predicts the solution to a typical problem by two different pre-fault and post-fault prediction pathways. The results, obtained by the integration of the predictions of those pathways, clearly indicate the success of our model in solving the topology (ir)recoverability prediction problem compared to the best of current strategies found in the literature

Design an Improved Trust-based Quality of Service AwareRouting in Cognitive Mobile Ad-Hoc Network

Mobile ad hoc networks (MANETs) are wireless networks that can be configured at will. It has no infrastructure and centralized control, so it is only suitable for provisional communications. In a dynamically topological and resource-constrained network, ensuring QoS and security is challenging. MANETs are dynamic networks, so navigating them can be challenging and more susceptible to attacks. MANET requires significant memory, speed, and transmission bandwidth for conventional security measures like cryptographic techniques. Consequently, these methods are unsuitable for identifying malicious behaviour or self-centered nodes. Nodes that are malicious, selfish, or malfunctioning can be identified based on the trust method, which calculates how much trust exists between them. A trust-based QOS-aware routing protocol is proposed in this paper to calculate trust in MANET (I-TQAR). The tree important performance metrics are considered for result validation such as delay, throughput and packet delivery ratio (PDR). I-TQAR offers significantly improved performance in all areas compared to the existing TQR and TQOR protocols

The k-Neigh Protocol for Symmetric Topology Control in Ad Hoc Networks

We propose an approach to topology control based on the principle of maintaining the number of neighbors of every node equal to or slightly below a specific value k. The approach enforces symmetry on the resulting communication graph, thereby easing the operation of higher layer protocols. To evaluate the performance of our approach, we estimate the value of k that guarantees connectivity of the communication graph with high probability. We then define k-Neigh, a fully distributed, asynchronous, and localized protocol that follows the above approach and uses distance estimation. We prove that k-Neigh terminates at every node after a total of 2n messages have been exchanged (with n nodes in the network) and within strictly bounded time. Finally, we present simulations results which show that our approach is about 20% more energy-efficient than a widelystudied existing protocol

A Framework for Incentive Compatible Topology Control in Non-Cooperative Wireless Multi-Hop Networks

In this paper we consider the problem of building and maintaining a network topology with certain desirable features in a wireless multi-hop network where nodes behave like selfish agents. We first provide examples showing that existing topology control approaches are not resilient to strategic node behavior, indicating the need of considering possible selfish node behavior at the design stage. Given this observation, we propose a general framework that can be used as a guideline in the design of incentive compatible topology control protocols. As examples of application of our framework to specific topology control protocols, we present incentive compatible distributed algorithms for building the minimum spanning tree (MST) and the k-closest neighbors graph, which are very well-known topology control approaches. To the best of our knowledge, the ones presented in this paper are the first incentive compatible realizations of topology control presented in the literature

Resilient Wireless Sensor Networks Using Topology Control: A Review

Wireless sensor networks (WSNs) may be deployed in failure-prone environments, and WSNs nodes easily fail due to unreliable wireless connections, malicious attacks and resource-constrained features. Nevertheless, if WSNs can tolerate at most losing k − 1 nodes while the rest of nodes remain connected, the network is called k − connected. k is one of the most important indicators for WSNs’ self-healing capability. Following a WSN design flow, this paper surveys resilience issues from the topology control and multi-path routing point of view. This paper provides a discussion on transmission and failure models, which have an important impact on research results. Afterwards, this paper reviews theoretical results and representative topology control approaches to guarantee WSNs to be k − connected at three different network deployment stages: pre-deployment, post-deployment and re-deployment. Multi-path routing protocols are discussed, and many NP-complete or NP-hard problems regarding topology control are identified. The challenging open issues are discussed at the end. This paper can serve as a guideline to design resilient WSNs

Rollout Algorithms for Integrated Topology Control and Routing in Wireless Optical Backbone Networks

We consider a wireless backbone network with free space optical point-to-point links. Such a network could form a backbone for either a cellular or hierarchical ad hoc network. Each backbone node has a limited number of transceivers with which to establish links to neighbors. Given estimated aggregate traffic demands between source and destination backbone nodes, we consider the problem of topology control and routing-- determining which links to set up and which routes to establish in order to maximize the throughput. While the problem may be formulated as an integer linear program, its solution is computationally prohibitive. Consequently, we use the mathematical technique of rollout to develop effective heuristic algorithms. Through simulation experiments, we show that the performance of the rollout algorithms we derive is clearly superior to that of the initial heuristic algorithms on which they are based