Towards k-Connectivity in Heterogeneous Sensor Networks under Pairwise Key Predistribution

We investigate the connectivity of wireless sensor networks under the random pairwise key predistribution scheme of Chan Under the assumption of full visibility, this reduces to studying the connectivity in the so-called random K-out graph H (n;K); here, n is the number of nodes and K <; n is an integer parameter affecting the number of keys stored at each node. We show that if K ≥ 2 (respectively, K=1), the probability that H (n;K) is a connected graph approaches 1 (respectively, 0) as n goes to infinity. For the one-law this is done by establishing an explicitly computable lower bound on the probability of connectivity. Using this bound, we see that with high probability, network connectivity can already be guaranteed (with K ≥ 2) by a relatively small number of sensors. This corrects earlier predictions made on the basis of a heuristic transfer of connectivity results available for Erdos-Renyi graphs.

We investigate k-connectivity in secure wireless sensor networks under the random pairwise key predistribution scheme with unreliable links; a network is said to be k-connected if it remains connected despite the failure of any of its (k - 1) nodes or links. With wireless communication links modeled as independent on-off channels, this amounts to analyzing a random graph model formed by intersecting a random K-out graph and an Erdös-Rényi graph. We present conditions on how to scale the parameters of this intersection model so that the resulting graph is k-connected with probability approaching to one (resp. zero) as the number of nodes gets large. The resulting zero-one law is shown to improve and sharpen the previous result on the 1-connectivity of the same model. We also provide numerical results to support our analysis and show that even in the finite node regime, our results can provide useful guidelines for designing sensor networks that are secure and reliable.

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.

Most of existing pairwise key predistribution schemes (PKPS) for wireless sensor networks (WSN) have a common security vulnerability that an illegitimate node can use the keying material of a compromised node to set up pairwise keys with any non-compromised nodes in the network. Using this vulnerability, we propose the clone attack against WSN. To our knowledge, by far no PKPS can defend against this attack We propose a polynomial based space-time related pairwise key predistribution scheme (PSPP), in which the keying material of a node can only works at its initial deployment location. Analysis shows that PSPP cannot only defend against the clone attack but also even baffle the execution of other attacks, e.g. sybile attack cannot work in PSPP. Finally, we propose the extended PSPP (EPSPP), which has better collusion resistance.

This article addresses the problem of space-partitioning in heterogeneous sensor networks, where the nodes have uniform symmetric sensing patterns, though their maximum sensing distance differs. Inappropriateness of classical spatial Voronoi tessellation for coverage purposes is denoted, compared to the proposed space-partitioning technique, which takes into account this heterogeneity. Unlike weighted-Voronoi techniques, the latter's definition is reflected in a way that the assigned regions are convex sets, their construction is computationally-efficient, while special properties of Voronoi diagrams, which hold for homogeneous networks, are kept active. Simulation results confirm the efficacy of the proposed region-assignment scheme when dealing with heterogeneous networks, in contrast with classical Voronoi tessellation.

We consider secure and reliable connectivity in wireless sensor networks that utilize the heterogeneous random key predistribution scheme. We model the unreliability of wireless links by an on/off channel model that induces an Erdős-Renyi graph, while the heterogeneous scheme induces an inhomogeneous random key graph. The overall network can thus be modeled by the intersection of both graphs. We present conditions (in the form of zero-one laws) on how to scale the parameters of the intersection model, so that with high probability: i) all of its nodes are connected to at least ${k}$ other nodes, i.e., the minimum node degree of the graph is no less than $ {k}$ , and ii) the graph is $ {k}$ -connected, i.e., the graph remains connected even if any $ {k} - {1}$ nodes leave the network. These results are shown to complement and generalize several previous results in the literature. We also present numerical results to support our findings in the finite-node regime. Finally, we demonstrate via simulations that our results are also useful when the on/off channel model is replaced with the more realistic disk communication model .

We present geometric broadcast for sensor and actor networks (GBSA), a novel broadcasting protocol for heterogeneous wireless sensor and actor networks. While broadcasting is a very energy-expensive protocol, it is also widely used as a building block for a variety of other network layer protocols. Therefore, reducing the energy consumption by optimizing broadcasting is a major improvement in heterogenous sensor networking. GBSA is a distributed algorithm where nodes make local decisions on whether to transmit based on a geometric approach. GBSA does not need any neighborhood information and imposes very low communication overhead. GBSA is scalable to the change in network size, node type, node density and topology. GBSA accommodates seamlessly such network changes, including the presence of actors in heterogeneous sensor networks. Indeed GBSA takes advantage of actor nodes, and uses their resources when possible, thus reducing the energy consumption by sensor nodes. Through simulation evaluations, we show that GBSA is very scalable and its performance is improved by the presence of actors. At best of our knowledge, GBSA is the first broadcast protocol designed specifically for heterogeneous sensor and actor networks.

In this work, we propose a small world model to design Heterogeneous Sensor Networks (HSNs). The proposed model takes into account the communication pattern of this network to create shortcuts directed to the monitoring node, decreasing data communication latency. The endpoints of these shortcuts are nodes with more powerful communication range and energy reserves to support the long communication range. However, this kind of communication causes a high interference in the wireless channel. For this, the proposed model uses the multi-interface and multi-channel capability of the MAC layer to reduce the number of collisions during data communication. Simulation results showed that with just a few powerful nodes, a wireless sensor network can be tuned into a HSN with small world features. Also, when the shortcuts are directed to the monitoring node and assigned to a different wireless channel, the number of collisions and the data communication latency are reduced.

Heterogeneous network user authentication keys are vulnerable to plain text attacks, resulting in poor encryption performance. Therefore, a heterogeneous bilinear pairing signcryption scheme is proposed. The symbol frequency detection method is used to detect symbols of user authentication data, establish an ORK user protocol in a heterogeneous network, and perform a pairwise signcryption scheme to linearly encode user cognitive information in a heterogeneous network. Use Ryption technology to authenticate and re-sign users in heterogeneous networks, and use a bilinear pairing signature encryption scheme to control cipher text in user processes to encrypt identity authentication information in heterogeneous networks. Establish a statistical analysis model to encrypt user authentication information in a heterogeneous network to achieve intelligence. Simulation results show that the method has good scrambling ability and strong anti-attack ability. It is used for bilinear pairing signature encryption of user authentication keys in heterogeneous networks.

Target Coverage and Network Connectivity in Wireless Sensor Networks (WSNs) plays a momentous role in the field of monitoring environment, habitant observing, disaster recovery, surveillance, etc. Coverage and Network Connectivity collectively can be considered as a proportion of Quality of Service (QoS) in a sensor network. It implies the coverage of each point in the detecting field while in the meantime fulfilling the measure that each node is surrounded by the equivalent neighbourhood of at least one other node. Many primary issues influence the outline and performance of WSN. A Comprehensive survey is made based on the scheduling algorithm and set cover approach, in which we analyze various approaches and their algorithm complexity. Firstly, the scheduling algorithm intermittently provides the required data service with guaranteed efficiency. This methodology can efficiently reduce the entire number of active nodes in the network, resulting in maximizing the network lifetime. Secondly, the set cover approach plays a major role in solving target coverage problem which group sensors into each cover set thereby, target coverage was achieved. Typical issues and open research challenges are addressed by classifying the approaches available in literature into three broad categories namely, adaptable coverage radius, coverage deployment strategy, and sleep scheduling. This survey aims to provide a better perceptive of the existing open challenges and possible futuristic approaches for target coverage and network connectivity in wireless sensor networks.

Information fusion helps telemonitoring systems to better unify data collected from different sensors. This paper presents last improvements made on a telemonitoring system aimed at enhancing remote healthcare for dependent people at their homes. The system is based on SYLPH, a novel platform based on a service-oriented architecture approach over a heterogeneous Wireless Sensor Networks infrastructure to create intelligent environments. Because of SYLPH, the system allows the interconnection of several sensor networks from different wireless technologies, such as ZigBee or Bluetooth. Furthermore, the SYLPH platform can be executed over multiple wireless devices independently of their microcontroller or the programming language they use.

On the design of resilient heterogeneous wireless sensor networks based on small world concepts

Energy saving to prolong the network life is an important design issue while developing a new routing protocol for wireless sensor network. Clustering is a key technique for this and helps in maximizing the network lifetime and scalability. Most of the routing and data dissemination protocols of WSN assume a homogeneous network architecture, in which all sensors have the same capabilities in terms of battery power, communication, sensing, storage, and processing. Recently, there has been an interest in heterogeneous sensor networks, especially for real deployments. This research paper has proposed a new energy aware clustering protocol (EACP) for heterogeneous wireless sensor networks. Heterogeneity is introduced in EACP by using two types of nodes: normal and advanced. In EACP cluster heads for normal nodes are elected with the help of a probability scheme based on residual and average energy of the normal nodes. This will ensure that only the high residual normal nodes can become the cluster head in a round. Advanced nodes use a separate probability based scheme for cluster head election and they will further act as a gateway for normal cluster heads and transmit their data load to base station when they are not doing the duty of a cluster head. Finally a sleep state is suggested for some sensor nodes during cluster formation phase to save network energy. The performance of EACP is compared with SEP and simulation result shows the better result for stability period, network life and energy saving than SEP.

Fault tolerant aggregation in heterogeneous sensor networks

Conventional localization of unmanned surface vehicle (USV) predominantly relies on a single integrated navigation system, typically comprising a global navigation satellite system (GNSS) and an inertial navigation system. However, the GNSS signals are vulnerable to external perturbations, which can substantially compromise the positioning accuracy. To achieve high-precision positioning of USV, this article investigates the cooperative localization problem for a class of USV in peer-to-peer heterogeneous sensor networks. A cooperative consensus localization (CCL) algorithm is proposed for the USV operating within heterogeneous sensor networks composed of ultra wideband modules and an integrated navigation system. The algorithm adopts a consensus-based state estimation approach founded on the principle of consensus on information. By integrating these methodologies, the proposed CCL algorithm enables high-precision localization of USVs, even in the presence of unknown inputs originating from the integrated navigation system. Furthermore, the stability of the proposed CCL algorithm is guaranteed under mild assumptions, including bounded system parameters, the doubly-stochastic property of the weight matrix, and connectivity in the heterogeneous sensor network. Specifically, the estimation error of each estimator remains uniformly bounded in the mean-square sense. Finally, the effectiveness and superiority of the proposed technique are validated through both numerical simulations and practical experiments.