Event-driven Wireless Sensor Networks Research Articles

A New Self-Management Model for Large-Scale Event-Driven Wireless Sensor Networks

Event-driven wireless sensor networks (WSNs) are equipped with the sensor nodes which are able to capture the vital changes in the measurements and report them to the base station. Due to the nature of harsh and unattended environments, it is impossible to install sensor nodes manually. Therefore, a random deployment fashion such as by aircraft is required. However, with high probability, sensor nodes will not have uniform distribution in the environment which will cause “hole” in the network. In another issue, sensor nodes are limited in energy supply and transmission range, and thus an appropriate technique is essential to calculate energy efficient routes to relay data from the sensor nodes to the base station. In hierarchical routing category, clustering techniques attempt to partition the sensor nodes in the network to appropriate groups and select the cluster heads to contact with the base station directly. However, in large scale WSNs, most of the sensor nodes are far from the base station and cannot contact directly. Most of the clustering techniques do not consider how cluster heads can reach to the base station. In our research, A Delaunay triangulation approach is employed to detect holes in the network. Then, due to the overhead of clustering methods to define cluster areas, a virtual gridding scheme is applied to define cluster areas. To overcome uncertainties in the environment, a fuzzy logic-based approach is designed to select appropriate cluster heads and hop-nodes in a distributed manner. The experimental results prove the effectiveness and accuracy of our proposed model and applicability to large scale WSNs.

A rule-driven multi-path routing algorithm with dynamic immune clustering for event-driven wireless sensor networks

In order to save energy for event-driven wireless sensor networks (WSNs) applied to emergency monitoring, a rule-driven multi-path routing algorithm with dynamic immune clustering (RDICMR) is proposed. The RDICMR algorithm is executed under the driven of condition rules and implementation rules. By applying the working mechanism of the biological immune system to the event-driven dynamic clustering algorithm for WSNs, where event as antigen, the records of clusters and routing paths of past events in the node׳s memory as antibodies, antibodies have the function of collecting and preserving memories, as such it is convenient to response to antigens that are similar to the previous antigen timely. When similar events happen and satisfy the affinity and energy rules, the sensor nodes can directly call antibodies in the memory to build clusters of events and transfer data quickly. Besides, we change the cycle of the network dynamically according to the updating cluster cycle rule. The proposed RDICMR algorithm saves a lot of energy in the process of building clusters and data transmission, increases the amount of data transmission and prolongs the lifetime of the network.

WDARS: A Weighted Data Aggregation Routing Strategy with Minimum Link Cost in Event-Driven WSNs

Realizing the full potential of wireless sensor networks (WSNs) highlights many design issues, particularly the trade-offs concerning multiple conflicting improvements such as maximizing the route overlapping for efficient data aggregation and minimizing the total link cost. While the issues of data aggregation routing protocols and link cost function in a WSNs have been comprehensively considered in the literature, a trade-off improvement between these two has not yet been addressed. In this paper, a comprehensive weight for trade-off between different objectives has been employed, the so-called weighted data aggregation routing strategy (WDARS) which aims to maximize the overlap routes for efficient data aggregation and link cost issues in cluster-based WSNs simultaneously. The proposed methodology is evaluated for energy consumption, network lifetime, throughput, and packet delivery ratio and compared with the InFRA and DRINA. These protocols are cluster-based routing protocols which only aim to maximize the overlap routes for efficient data aggregation. Analysis and simulation results revealed that the WDARS delivered a longer network lifetime with more proficient and reliable performance over other methods.

Quasi Random Deployment Strategy for Reliable Communication Backbones in Wireless Sensor Networks

Topology construction and topology maintenance are significant sub-problems of topology control. Spanning tree based algorithms for topology control are basically transmission range based type construction algorithms. The construction of an effective backbone, however, is indirectly related to the placement of nodes. Also, the dependence of network reliability on the communication path undertaken by the message, subject to the place of event, remains unattended. To address this problem, we employ communication backbones (Prim’s algorithm and breadth first search (BFS)) and compute reliability based on the availability of paths for consistent message delivery from the place of event to the sink location in event driven wireless sensor networks. Our article analyses the communication reliability of a wireless sensor network in context to a topology governed by random and deterministic deployment methods. To comprehend the effect of topology on the communication reliability of a wireless network; “the within communication radii” constraint is satisfied. ANOVA is performed to validate the effect of node placement schemes on the reliability subject to varying radio ranges. It is observed that a ‘quasi’ random placement of nodes increases the communication reliability of the existing algorithms employed for analysis.

A Passive Wake-Up Circuit for Event Driven Wireless Sensor Network Applications

The lifetime of battery operated sensor nodes is a critical issue. In the case of event driven applications where events take place infrequently, most of the energy is wasted in idle listening by the sensor nodes. The sensor node in continuous idle listening mode drains the batteries approximately in two days. This paper describes a passive wake-up circuit (PWUC), designed for 2.45 GHz ISM band, to suppress the idle listening by waking-up the sensor nodes asynchronously. The proposed PWUC consists of receiving antenna, RF rectifier and matching network. The impedance and number of stages of the RF rectifier have been optimized to yield the maximum sensitivity and conversion efficiency. The lumped component based external matching network has also been proposed to boost-up the received input voltage through antenna. The purpose behind the use of external matching network is to reduce the fabrication cost of RF rectifier. Very few realizations of passive wake-up circuits are reported in the literature and none of them presents the sensitivity and global conversion efficiency above -11 dBm and 30–40%, respectively. The designed PWUC gives an output voltage of 1.8 V for a -23 dBm received RF power and a 1 MΩ load, which translates to 69% global power conversion efficiency (GPCE). RF rectifier is designed in UMC 180-nm 1P6M CMOS standard process.

RC-MAC: A Receiver-Centric MAC Protocol for Event-Driven Wireless Sensor Networks

Event-driven wireless sensor networks (WSNs) usually operate under light traffic load. However, when an event is detected, a large number of packets may be generated. A MAC protocol designed for this kind of WSNs should be able to swiftly adapt to the two conditions. Most WSN MAC protocols are optimized for light traffic for the energy efficiency consideration. In this paper, we propose a novel receiver-centric MAC protocol called RC-MAC that seamlessly integrates duty cycling and receiver-centric scheduling, providing high throughput without sacrificing the energy efficiency. To handle bursty traffic triggered by an event, RC-MAC takes advantage of the underlying data gathering tree structure of WSNs and the multichannel technique supported by current IEEE 802.15.4 RF transceivers to assist scheduling of medium access. The throughput is improved in two phases with receiver-centric medium access scheduling and distributed channel assignment. First, on a data gathering tree, a receiver is able to coordinate the medium access of multiple senders so as to reduce collisions and achieve high throughput. Second, different receivers coordinate their senders in different channels and the throughput is further improved by allowing parallel data gathering. Observing packet processing time on low cost sensor nodes, we design a scheduling pattern that ensures fairness between source nodes without sacrificing the throughput. We evaluate the performance of our RC-MAC through measurements of an implementation in TinyOS on TelosB motes and extensive ns-2 simulations. Compared with contention-based and scheduling-based MAC protocols, we show that the throughput and the fairness under heavy traffic load are significantly improved by the receiver-centric scheduling. Due to the high throughput, the energy efficiency is also improved.

An Energy Efficient Collision Avoidance Method for CEDEEP Protocol

The present paper proposes a novel Energy Efficient Collision Avoidance Method (EECAM) for Collaborative Event Driven Energy Efficient Protocol (CEDEEP). EECAM makes possible higher energy savings by introducing nodes prioritization according to distinctive properties of CEDEEP protocol and event driven Wireless Sensor Network (WSN) applications. In this research the higher energy conservation caused by deployment of EECAM within CEDEEP have been investigated. A stochastic model of the one hop network is developed and the effectiveness of EECAM is illustrated considering Sift protocol in event driven WSN applications. The results of the evaluations confirmed significant improvements in energy consumption of CEDEEP when EECAM is used. Therefore, this research gives strong evidences that use of EECAM instead of Sift at media access control (MAC) layer results into higher energy efficiency of CEDEEP in event driven applications. Furthermore, this higher energy efficiency of CEDEEP with EECAM ensures considerably longer lifetime of WSNs in event driven application scenarios. Keywords: CEDEEP, event driven, media access control, multiple access, sift.

Adaptive multiresolution sampling in event-driven WSNs

In time driven applications we are often bound to make a keen compromise between the sampling resolution (or sampler architecture) and available resources. This is especially true in WSNs (Wireless Sensor NetworkS), although the complexity of event driven environments present us new opportunities for optimizations. In this paper we propose a multi resolution sampling protocol for event driven WSNs that can dynamically adapt to event signatures and can efficiently schedule resource intensive samplers. The system can monitor the environment by a resource optimized sampler which is only to detect events and not to store or process any samples. When scheduled the high resolution sampler is activated to sample the appropriate physical property of the phenomenon marked by the event, via resolution optimized hardware. Since it takes time to detect an event (triggered by the signal we already ought to sample) and to power up the high resolution, resource intensive sampler, we must start the sampling before the signal is detected. This calls for dynamic event forecasting, which is the main feature of the proposed system.

QoS Analysis for a Nonpreemptive Continuous Monitoring and Event-Driven WSN Protocol in Mobile Environments

Evolution in wireless sensor networks (WSNs) has allowed the introduction of new applications with increased complexity regarding communication protocols, which have to ensure that certain QoS parameters are met. Specifically, mobile applications require the system to respond in a certain manner in order to adequately track the target object. Hybrid algorithms that perform Continuous Monitoring (CntM) and Event-Driven (ED) duties have proven their ability to enhance performance in different environments, where emergency alarms are required. In this paper, several types of environments are studied using mathematical models and simulations, for evaluating the performance of WALTER, a priority-based nonpreemptive hybrid WSN protocol that aims to reduce delay and packet loss probability in time-critical packets. First, randomly distributed events are considered. This environment can be used to model a wide variety of physical phenomena, for which report delay and energy consumption are analyzed by means of Markov models. Then, mobile-only environments are studied for object tracking purposes. Here, some of the parameters that determine the performance of the system are identified. Finally, an environment containing mobile objects and randomly distributed events is considered. It is shown that by assigning high priority to time-critical packets, report delay is reduced and network performance is enhanced.

A low-delay energy-efficient decision strategy in duty-cycled wireless sensor networks

In many event–driven wireless sensor networks (WSNs) where sensor nodes are often put in a duty–cycled mode for energy saving, event delay and energy efficiency are always at odds. Detection of rare events in a fast and energy–efficient manner is an important and challenging issue in WSNs. In this paper, we aim at the moderate–scale networks and propose a fully distributed low–delay energy–efficient decision strategy (LEDS) to handle this problem. By adopting an online cooperative scheme between neighbouring sensing nodes, LEDS avoids the redundant transmissions and achieves a good network performance involving delay and energy efficiency. Moreover, we also extend our solution to the large–scale networks by combining LEDS with a sink augmentation scheme. Finally, our simulation results reveal that LEDS exhibits a quite good tradeoff between average event delay and network lifetime, and also outperforms the existing solution.

Tools for the selection of the transmission probability in the cluster formation phase for Event-Driven Wireless Sensor Networks

In the literature, it is common to find studies on Wireless Sensor Networks (WSNs) that consider the Carrier Sense Multiple Access (CSMA) protocol with a fixed transmission probability for means of the random access strategy. This is especially true for event-driven applications for clusteredbased architectures. However, due to the highly variable environment in these networks in terms of the number of nodes attempting a transmission (at the beginning of the cluster formation all nodes in the network contend for the channel, while at the end only a few nodes attempt a transmission), a fixed transmission probability may not entail an adequate performance. Specifically, the energy consumption may be too high by considering a fixed transmission strategy, because the use of a low transmission probability at the beginning of the cluster formation reduces the collision probability, but at the end entails long idle periods. In view of this, the effects of three different transmission probability strategies for event-driven WSNs are studied. Based on the obtained results, it is shown that a careful selection of the transmission probability is required in order to prolong the network lifetime.

Network Reliable Routing Protocol for Event-Driven Wireless Sensor Network

Wireless Sensor Networks is a collection of various densely deployed sensor nodes which is implemented in a variety of applications such as Home, Medical, Military, Security Surveillance and Combat Field Reconnaissance etc. An eventdriven wireless sensor networks (EWSNs) is a type of wireless sensor network in which the desired information is disseminated to the sink more reliably. Another important function of EWSN is the accurate event detection so that the probability of false alarm becomes low. Likewise WSN, sensor nodes in EWSNs are also energy constrained thereby designing energy-efficient algorithm becomes an important factor for extending the life span of the event-driven wireless sensor network. In EWSNs, clustering is used for efficient use of constrained resources for energy saving. This paper provides a novel Network Reliable Routing Protocol for EWSNs. This protocol provides better data aggregation by using clustering at initial and reliable data dissemination by using multipath routing method which makes the network fault tolerant. Network Reliable Routing Protocol setup a routing path from source to sink. It also minimizes unnecessary activation of nodes during data dissemination process. Performance results show that Network Reliable Routing Protocol handles more events than already exists ESDC and also achieves the energy efficiency objective.

Queue-based congestion detection and multistage rate control in event-driven wireless sensor networks

Protocols for sensor networks have traditionally been designed using the best effort delivery model. However, there are many specific applications that need reliable transmissions. In event-driven ...

Reliability Analysis for a Data Flow in Event-Driven Wireless Sensor Networks

For the purpose of designing more reliable networks, we extend the traditional reliability analysis from wired networks to wireless networks with imperfect components. This paper aims to study the reliability of a data flow in event-driven wireless sensor networks with acknowledgment-based transmission scheme. Initially, an event-driven wireless sensor network model is described in terms of limited node battery energy and shadowed fading channels. Then, in order to analyze the network reliability, wireless link reliability and node energy availability are investigated, respectively. Further the analytical expressions of the instantaneous network reliability and the mean time to failure are derived. Finally, the simulation results validate the correctness and accuracy of the analytical results.

Topology-Related Metrics and Applications for the Design and Operation of Wireless Sensor Networks

The use of topological features, more specifically, the importance of an element related to its structural position, is a subject widely studied in the literature. For instance, the theory of complex networks provides centrality measures that have been applied to a large variety of fields (e.g., social sciences and biology). In this work, we propose a new topological measure, the Sink Betweenness (SBet), which stems from the theory of complex networks but is adapted to Wireless Sensor Networks (WSNs) to capture relevant information for this kind of network. We also provide a distributed algorithm to calculate it, and show its applicability to two different scenarios. The first one is focused on data fusion applications for event-driven WSNs, where we devise a tree-based data collection algorithm that takes advantage of node centrality to improve the data fusion efficiency. The second scenario is focused on energy balancing problems, more specifically in a problem called energy hole , where nodes closer to the sink are more likely to relay a larger number of packets than those that are further. This phenomenon is strongly related to the topology induced by the deployment of nodes along the sensor field, and it can be effectively captured by the SBet metric. Thus, we devise a data collection algorithm that is able to distribute the relay task more evenly. Simulation results show that the SBet metric can be satisfactorily used in both scenarios. We compare the proposed approach with some of the most efficient available data fusion algorithms, and show that the proposed algorithm generates consistently good-quality data collection infrastructures which require significantly smaller overhead. The use of SBet allows to alleviate the energy-hole effects by evenly balancing the relay load, and thus increasing the network lifetime. These two applications illustrate how the topology awareness can be used to improve different network functions in a WSN.

IM2PR: interference-minimized multipath routing protocol for wireless sensor networks

With respect to the inherent advantages of multipath routing, nowadays multipath routing is known as an efficient mechanism to provide even network resource utilization and efficient data transmission in different networks. In this context, several multipath routing protocols have been developed over the past years. However, due to the time-varying characteristics of low-power wireless communications and broadcast nature of radio channel, performance benefits of traffic distribution over multiple paths in wireless sensor networks are less obvious. Motivated by the drawbacks of the existing multipath routing protocols, this paper presents an Interference-Minimized MultiPath Routing protocol (IM2PR) which aims to discover a sufficient number of minimum interfering paths with high data transmission quality between each event area and sink node in order to provide efficient event data packet forwarding in event-driven wireless sensor networks. Extensive performance evaluations show that IM2PR presents improvements over the Micro Sensor Multipath Routing Protocol and Energy-Efficient data Routing Protocol as follows: 50 and 70 % in term of packet reception ratio at the sink, 44 and 80 % in term of goodput, 33 and 40 % in term of packet delivery latency, 40 and 57 % in term of energy consumption, 50 and 60 % in term of packet delivery overhead.

Vehicular traffic monitoring in V2I systems using a wireless sensor network

In the near future the majority of the automotive systems will strongly rely on the exchange of information among vehicles or infrastructure to improve the driving conditions, increment security or simply have access to internet and entertainment services. This is the reason why the research and development of Vehicular Ad-Hoc Networks is very important nowadays. In this paper, a design and analysis of a Vehicular Ad-Hoc Network (VANET) assisted by an event driven Wireless Sensor Network (WSN) for traffic monitoring in a highway is presented. The aforementioned WSN is based on the well-known LEACH protocol. However, a key modification is proposed in order to increase the network lifetime for applications on VANETs. The basic idea is to minimize the overlapping areas among neighboring clusters in order to reduce redundancy and to have a better coverage of the supervised highway with a lower transmission cost. Additionally, two different methods for the event reporting are proposed. In the first one, the traffic information is transmitted exclusively among the WSN nodes, while the second method makes use of the vehicles in order to relay the information to the sink. The proposed methods are analyzed in terms of energy consumption and average report delay.

Phase imperfect collaborative event driven energy efficient protocol

The present paper proposes a novel Collaborative Event Driven Energy Efficient Protocol (CEDEEP) for single hop event driven Wireless Sensor Networks (WSN) with phase imperfect collaborative communication. CEDEEP takes advantages of spatiotemporal features of event driven WSN and uses collaborative communication to conserve more energy. In this research the effects of imperfectly phase synchronised signals on the performance of CEDEEP for collaborative event driven WSN have been investigated. An analytical model of the network is developed and the effectiveness of CEDEEP is considering in Rayleigh fading and Additive White Gaussian Noise (AWGN) channel. The results of the simulation confirmed CEDEEP efficiency even when imperfect phase synchronisation exists between received collaborative signals. Therefore, this research gives strong evidences of CEDEEP ability to ensure high energy efficient operation of phase imperfect collaborative event driven WSN over Rayleigh fading and AWGN channels.

Anycast Technique to Increase the Life Time of Wireless Sensor Network

Wireless sensor network is collection of sensor nodes and one sink node. Sensor nodes sense the signals and forward to the sink node. In event driven wireless sensor network where some event is happened that event is sense by one of the sensor node and forward to sink node. Sensor nodes are small in size so the energy capacity of sensor node is very less. In the event driven wireless sensor network energy is consumed when radios are on waiting for packet to arrive. In most of the Event-Driven wireless sensor network Sleep Wake-Up scheduling is used where most of the time sensor node is in sleep mode so that the energy is saved but one drawback of this sleep wake up scheduling is that it introduces delay in the network. So it is very important that to save the energy so that life time of sensor node is maximize for this “Anycat Packet ” Forwarding scheme is used where each node forwards the packet to the first neighboring node that wake up among multiple nodes. In sleep wake-up scheduling energy consumed by sensor nodes are depends on the wake up rate of the node. If the wake –up rate of node having less energy is more then that node not alive more time. This paper gives the details of how anycast forwarding scheme is used along with Sleep Wake up scheduling to balance the wake up rates of all sensor nodes so that the lifetime of WSN is increase.

Reliability analysis for a data flow in event-driven wireless sensor networks using a multiple sending transmission approach

Reliability analysis is an important issue in wireless sensor networks (WSNs). This paper aims to study the reliability of a data flow in event-driven wireless sensor networks with multiple sending transmission approach without acknowledgments. Initially, an event-driven wireless sensor network model is described in terms of limited node battery energy and shadowed fading channels. Then, in order to analyze the network reliability, the wireless link reliability and the node energy availability are investigated, respectively. Furthermore, the analytical expressions of the instantaneous network reliability and the mean time to failure (MTTF) are derived. Finally, the simulation results validate the correctness and accuracy of the analytical results.