Using mobile relays to prolong the lifetime of wireless sensor networks

In wireless sensor networks, sensor nodes have limited battery power. Data aggregation is an important technique in a wireless sensor network to reduce the energy consumption by eliminating the redundant data and delivering useful data to the user. Data aggregation technique is used to gather the data sensed by the sensor nodes in the network and aggregates the sensed data in an energy-efficient way so that overall network lifetime can be increased. Cluster, tree, chain, and grid are some of the architectures for data aggregation in wireless sensor networks. In this paper, authors present an analysis-based survey of data aggregation protocols for tree-based architecture in wireless sensor networks. The authors analyze each algorithm on the basis of performance measurements such as network lifetime, energy consumption, and node distance. Authors also compare these algorithms on the basis of the preferred parameter and a key feature of each algorithm. In the fifth section of the paper, authors described the proposed approach to construct the data aggregation tree to maximize the network lifetime. In the proposed approach, authors used distance parameter to construct minimum spanning tree, and other parameters such as load and energy are preferred in a balanced manner to reduce the energy consumption and to maximize the network lifetime.

Traditionally, wireless sensor network (WSN) was static, but due to the necessity of today's applications, there has been a paradigm shift from a static WSN to dynamic mobile WSN. This dynamism can be realised by adding extra network elements called mobile entities (MEs) like mobile sinks (MSs), mobile cluster heads (MCHs), mobile relays (MRs), mobile sensor nodes (MSNs), mobile agents (MAs) and mobile chargers (MCs) to a static network. The full potential of MEs can be harnessed to yield maximum benefits in static WSN. In this work, first we have analysed the parameters that affect the lifetime when an ME is added to a static network. Second, we present a survey and performance analysis of each of the MEs discussed in literature. Finally, this paper concludes with the simulations and summaries of each of the MEs. This paper intends to spark new interest and development in mobile-assisted WSN.

Traditionally, wireless sensor network (WSN) was static, but due to the necessity of today's applications, there has been a paradigm shift from a static WSN to dynamic mobile WSN. This dynamism can be realised by adding extra network elements called mobile entities (MEs) like mobile sinks (MSs), mobile cluster heads (MCHs), mobile relays (MRs), mobile sensor nodes (MSNs), mobile agents (MAs) and mobile chargers (MCs) to a static network. The full potential of MEs can be harnessed to yield maximum benefits in static WSN. In this work, first we have analysed the parameters that affect the lifetime when an ME is added to a static network. Second, we present a survey and performance analysis of each of the MEs discussed in literature. Finally, this paper concludes with the simulations and summaries of each of the MEs. This paper intends to spark new interest and development in mobile-assisted WSN.

This paper concerns the definition of an analytical model and distributed protocols for determining the routes of a mobile data collector (sink) traveling through the nodes of a wireless sensor network (WSN). The routes are determined with the overall aim of maximizing the network lifetime. The contribution of our work is twofold. First, we introduce a novel mixed integer linear programming formulation for determining the sink's route and the sojourn time at the different "sink sites." The model takes into account realistic parameters such as the maximum distance the sink can travel between sites, different sink mobility rates, as well as the costs to support and perform data routing. Solutions to the model provide the route of the sink as a sequence of sites and the sojourn times at those sites that induce the maximum network lifetime. We then propose the Greedy Maximum Residual Energy (GMRE) protocol for sink mobility. GMRE is distributed and localized, thus being suitable for wireless sensor networking. In GMRE the sink greedily keeps moving toward those areas in the network where there is the most residual energy, as if "drawn" to them. This heuristic is then compared with a very simple and energy-unaware protocol where the next site in the sink route is chosen randomly and uniformly each time the sink moves. Simulation results show that GMRE leads to improvements in network lifetime that are four times as much as the lifetime when the sink is kept static, while balancing energy consumption throughout the network.

In wireless sensor networks (WSNs), sensor nodes near static sink will have more traffic load to forward and the network lifetime will get largely reduced. This problem is referred to as the hotspot problem. Recently, adopting sink mobility has been considered as a good strategy to overcome the hotspot problem. Despite its many advantages, due to the dynamic network topology caused by sink mobility, data transmission to the mobile sink is a challenging task. To achieve efficient data dissemination, nodes need to reconstruct their routes toward the latest location of the mobile sink, which weakens the energy conservation aim. In this paper, we proposed an energy-efficient cluster-based dynamic routes adjustment approach (EECDRA) which aims to minimize the routes reconstruction cost of the sensor nodes while maintaining nearly optimal routes to the latest location of the mobile sinks. The network is divided into several equal clusters and cluster heads are selected within each cluster. We also set some communication rules that manage routes reconstruction process accordingly requiring only a limited number of nodes to readjust their data delivery routes toward the mobile sinks. Simulation results show that the mobile sinks for reducing reconstruction of route have improved the energy efficiency and prolonged lifetime of wireless sensor network.

This paper proposes a framework to maximize the lifetime of the wireless sensor networks (WSNs) by using a mobile sink when the underlying applications tolerate delayed information delivery to the sink. Within a prescribed delay tolerance level, each node does not need to send the data immediately as it becomes available. Instead, the node can store the data temporarily and transmit it when the mobile sink is at the most favorable location for achieving the longest WSN lifetime. To find the best solution within the proposed framework, we formulate optimization problems that maximize the lifetime of the WSN subject to the delay bound constraints, node energy constraints, and flow conservation constraints. We conduct extensive computational experiments on the optimization problems and find that the lifetime can be increased significantly as compared to not only the stationary sink model but also more traditional mobile sink models. We also show that the delay tolerance level does not affect the maximum lifetime of the WSN.

Maximization of lifetime of wireless sensor network (WSN) is an emerging area of research in present scenario. Many authors are performing their research work, so that they could achieve lower energy consumption for the sensor network which leads to increase in lifetime of network. Our work focuses on sink mobility in a fixed trajectory within a wireless sensor network while sensed data are required to be collected. We divide the whole sensor network into two different regions as direct communication area (DCA) and multi-hop communication area (MCA). Sensors node that lies in DCA is at one hop count distance from the sink node trajectory while sensors within MCA are at more than one hop count from the trajectory. We considered all the sensors that are within DCA as subsink nodes. During sink mobility, whenever a subsink is closer to the mobile sink node, then it starts transmitting its data to the sink node. But those sensors that are within MCA needs to search an appropriate sink node for sending its sensed data to the subsink so that on further stage, that subsink could provide those data to the sink node whenever it is in nearest proximity of that subsink. Basically, a sink node is the ultimate destination for the data while a subsink node acts as a relay node for the nodes that are within MCA. So our work is to find out the appropriate subsink node from a given set of subsinks. For doing so, we used location-aided routing on global positioning system (GPS)-enabled sensors and sink node. Our work is validated through simulation experiments using NS-2.

In this paper, we propose a novel hierarchical architecture for a large wireless sensor network (WSN) wherein sensors are arranged into a multi-layer architecture with the nodes at each layer interconnected as a de Bruijn graph and provide a hierarchical routing algorithm in the network. Using our approach, every sensor obtains a unique node identifier addressed by binary addressing fashion. We show that our algorithm has reasonable fault-tolerance, admits simple and decentralized routing, and offers easy extensibility. We also present simulation results showing the average delay, success data delivery radio in our approach. And we received acceptable results for some potential applications.

Wireless sensor networks with the mobile sink can help to prevent the hot-spot problem and improve the network lifetime. However, in practice, the trajectories of the sink can not ideally change due to the obstacle of the environment or the requirement of the application. The constraint on trajectory of the mobile sink causes the different connection time between the mobile sink and the sensor node, which might result in the imbalance depletion of energy. We propose here an efficient data gathering policy to jointly consider the constrained mobility of the sink and the different connection time at the sensor node. The policy increases the network lifetime in wireless sensor networks with path-constrained mobile sink by optimizing the assignment sensor node. In addition, we also propose the policy to cope with the overlapped connection time of the sink and sensor node due to the movement of the sink. The simulation results demonstrate the effectiveness of the proposed policy: by carefully considering the trajectory of the sink and effectively assigning the sensor node, the network lifetime is increased.

Using the mobile sink for data collection from all sensors is the most highly effective way to prolong the network lifetime of wireless sensor networks(WSNs). Many studies focused on the anchors selection, aiming to reduce the path length of mobile sink and prolong the network lifetime. However, the appropriateness and the number of the selected anchors, which significantly impact the network lifetime of the entire WSNs, still can be improved. This paper proposes a Dynamic Anchor Points Mechanism for data collection, called DAM, aiming to select appropriate anchors under the path length constraint for prolonging the network lifetime. The experimental results show that the proposed DAM outperforms existing data collection mechanisms in term of network lifetime and fairness index.

Recent studies have shown that utilizing a mobile sink to harvest and carry data from wireless sensor network (WSN) can enhance network operations and balance the network energy consumption. Because of the sink mobility, the paths between the sensor nodes and the sink change frequently, and have profound influence on the lifetime of WSN. To find an efficient protocol that can maintain the routes between the mobile sink and nodes with few network resources are important. We propose a swarm intelligent algorithm based route maintaining protocol in this paper to resolve this issue. The protocol utilizes the concentric ring mechanism to guide the route researching direction, and the optimal routing selection to maintain the data delivery route. Using the immune based artificial bee colony (IABC) algorithm to optimize the forwarding path, the protocol could find an alternative path efficiently when sink moves. The results of our experiments demonstrate that the protocol could balance the network traffic load.

Mobile sink has been a significant means to prolong the lifetime of Wireless Multimedia Sensor Networks (WMSNs). However, the mobility of the sink makes the modeling of the WMSNs lifetime a more complex issue. Considering the new properties introduced by a mobile sink, this paper proposed a novel model to define the lifetime of WMSNs with a mobile sink based on energy by taking into account the heterogeneity, network delay, delay jitter, data rate, and data accuracy. Tunable coefficients were introduced into the model for the balance of energy consumption and functions in the network. Both theoretical analysis and numerical simulation validate the correctness and effectiveness of the proposed model.

Extensive research is being done on Wireless sensor Networks (WSNs) in present decade. WSNs consist of large number of sensor nodes which perform sensing of certain phenomena and send the sensed data to the sinks. This operation consumes energy of sensor nodes which effects the lifetime of a network. To prolong the lifetime of WSNs various strategies and routing algorithms have been proposed. Use of mobile sinks has proved effective in this respect. In this paper we are analyzing the impact of multiple mobile sinks with proactive hierarchical clustering protocols LEACH and network reactive hierarchical protocol TEEN. This paper will give simulation based analysis of using multiple mobile sinks in network and their effect on lifetime of a network. Performance analysis will be done on basis of dead nodes, alive nodes, throughput and residual energy.

Wireless sensor networks (WSNS) is an important part of the perception layer for the Internet of Things (IoT). It is one of the basic tools of collecting data for the Internet of Things. Trusted architecture is key for trusted transmission in the wireless sensor networks and applying support of the Internet of Things. In the paper, the wireless sensor networks is studied for the Internet of Things in the farmland. Based on wireless sensor network architecture, the trusted architecture for farmland wireless sensor networks is designed. The control flow of trusted architecture is discussed in detail. Additionally the trusted protocol model and the implement frame and phases are presented detailed. And the experimental data records show the trusted architecture for farmland wireless sensor networks can afford trusted and reliable data transmission for wireless sensor networks.

Wireless Sensor Network Lifetime improvement is very well demonstrated using sink mobility effectively in the literature. The challenge taken up in the past research was to identify the shortest route that avoids obstacles and delivers the mobile sinks at the designated nodes. In this paper, we present a cluster-based approach for collecting the data and a heuristic algorithm for a well-planned work. The routing protocols may differ from application to application, due to a large number of sensor nodes the algorithm should be studied in a novel way. In this method, the nodes known as cluster heads collect information from different cluster points and sends data to the mobile sink following this clustering process. We also propose an energy-efficient data gathering algorithm for the collection of mobile sinks. Simulations were conducted using NS2 software to verify the efficiency of the proposed algorithm.