Data Store-and-Delivery Approach for Air-Ground Collaborative Wireless Sensor Network

Energy efficiency is a major factor in designing wireless sensor networks (WSNs). Clustering design and grid‐based scheme are one of the techniques to save energy in WSNs. However, for a mobile sink in WSNs, packet loss rate that occurs due to the sink mobility is also a significant challenge. Here, an enhanced routing‐G i protocol for a mobile sink in WSNs has been proposed to not only enhance energy efficiency but also minimise the packet loss rate. Simulation results show that the proposed protocol is more efficient than the previous protocols in terms of the network lifespan, energy efficiency, and packet delivery ratio. Thus, the proposed approach in this work could further be adapted to investigate highly mobility of sink in WSNs.

The advantages of deploying mobile sinks (MSs) in wireless sensor networks (WSNs) have attracted tremendous attention recently, because mobility of a sink provides an efficient method to improve data gathering performance in WSNs. However, in such kind of WSN, the efficiency of data dissemination is obviously affected by the trajectory of the MS. Therefore, optimal moving schemes of the MS have been studied in many researches. Nevertheless, in many cases, the trajectory of the MS is not able to change ideally as previous studies assumed but depending on the environmental conditions. In this paper, we focus on the efficiency of data gathering in WSN with a MS whose trajectory cannot change ideally and propose a new data diffusion scheme - implementing a new Pre-Diffusion Algorithm (PDA) in a hierarchical WSN aimed at improving data gathering efficiency. This hierarchical WSN is composed of several clusters, and datatransmission is done by higher powered cluster head (CH) node. Our scheme predetermines the cluster area where the MS is going to arrive in most probability in next period of time. MS fulfills data converging in the cluster head (CH)whose distance to the MS may the smallest compared with other CHs when data gathering starts. Thus more data can be collected with less trajectory length of MS. Simulation results show that our proposed scheme improves data gathering efficiency as compared to conventional scheme.

In this paper, an adaptive path construction approach for Mobile Sink (MS) in wireless sensor networks (WSNs) for data gathering has been proposed. The path is constructed based on selecting Rendezvous Points (RPs) in the sensing field where the MS stops in order to collect the data. Compared with the most existing RP-based schemes, which rely on fixed RPs to construct the path where these points will stay fixed during the whole network lifetime, we propose an adaptive path construction where the locations of the RPs are dynamically updated using a Fuzzy Inference System (FIS). The proposed FIS, which is named Fuzzy_RPs, has three inputs and one output. The inputs are: the remaining energy of the sensor nodes, the transmission distance between the RPs and the sensor nodes, and the number of surrounding neighbors of each node. The output of FIS is a weight value for each sensor node generated based on the previous three parameters and, thus, each RP is updated to its new location accordingly. Simulation results have shown that the proposed approach extends the network lifetime compared with another existing approach that uses fixed RPs. For example, in terms of using the first dead node as a metric for the network lifetime, when the number of deployed sensor nodes changes from 150 to 300, an improvement that ranges from 48.3% to 83.76% has been achieved compared with another related approach that uses fixed RPs.

In wireless sensor networks (WSNs) localization systems are required to provide position information of sensor nodes. Position information of sensor nodes with unknown physical positions is acquired with the help of beacons or anchors. Beacon placement is one of the prominent factors that shape the localization performance in sensor networks. Placing more beacons in a network is generally not a cost-effective idea. However, a carefully designed technique can increase the accuracy by placing a limited number of beacons. This paper presents a requirement based beacon placement algorithm to optimize number of beacons to cover the entire WSN. A novel algorithm for routing towards the mobile sink is also proposed, which utilizes the beacon nodes more than sensor nodes to route data towards a mobile sink. This strategy helps to reduce the energy consumption of the WSN and increase the network lifetime. Simulation result shows that the proposed beacon placement scheme is effective in a sensor network with high node density and also evaluates the proposed routing algorithm.

ODT: Optimal deadline-based trajectory for mobile sinks in WSN: A decision tree and dynamic programming approach

Wireless sensor networks (WSN) consist of large number of sensor nodes. These small and low cost sensor nodes are deployed in monitoring region of interest. Since sensors perform multiple functions such as data gathering and data transmission results in energy depletion, these effects the network lifetime. The nodes having tendency to fail due to energy depletion is the critical issue in WSN. Due to wide number of applications of WSN, it is required to enhance the life time of entire network. Proposed method in this paper is aimed to optimize the energy dissipation by modifying the CH (Cluster Head) selection approach in LEACH (Low Energy Adaptive Clustering Hierarchy) algorithm and avoids the energy-hole problem considering mobility to the sink node which helps to prolong the lifetime of entire network.

A wireless sensor network (WSN) consists of a large number of interconnected sensors, which provides unique features to visualize the real world scenario. It explores many opportunities in the field of research due to its wide range of applications in current fields that require survey and periodic monitoring which is inevitable in our daily life. However, the main limitations of such sensors are their resource constrained nature, mainly to conserve battery power for extending the network lifetime. We have proposed an algorithm for energy efficiency in WSN in which mobile sink node is used to operate the routing process considering the shortest path between multiple unequal clusters with reduced energy. This model also ensures non-occurrences of energy hole problems within the network area.

Life time and Energy Efficiency are important factors in the design of wireless sensor network. A critical issue during data collection is the formation of energy holes near the sink. Sensors near the sink have to participate in relaying data on behalf of other sensors and thus their energy will be depleted very quickly. The mobile sink movement yields the significant performance gained through decreasing the amount of energy consumption. In this study, we propose a Grid Based approach for Data Disseminating to the Mobile Sink in Wireless Sensor Network. Mapping the position of nodes and sink to virtual grid infrastructure construct our main contribution. So that the data which is buffered by nodes could be disseminated to the mobile sink to the optimal manner. Finally, comprehensive simulation reveals the superiority of proposed algorithm in various scenarios.

Geographic convergecast using mobile sink in wireless sensor networks

In wireless sensor networks, the existing real-time routing protocols for stationary sinks exploit a spatiotemporal approach, utilizing the delivery speed based on the end-to-end distance to fulfill the desired time deadline. This approach cannot be directly applied to a mobile sink since the distance can be varied depending on its movement. That is, the delivery speed cannot be determined without knowing the intermediate sensors to know the current location update of the mobile sink and control their transmission speeds. We focus on the real-time protocol for slowly varying mobile sink compared to transmission speed, which may be the most common case. By the slowly varying constraint, the movable area of a sink can be determined by the two factors: its moving distance and initial location. The movable area could provide the maximum transmission distance between a source and a mobile sink. This letter proposes a real-time data dissemination protocol for mobile sinks utilizing the movable area concept. Simulation results show the proposed protocol provides high success ratio of real-time requirement.

Using a single fixed sink in wireless sensor networks (WSNs) creates the hotspot problem. Recently, the mobile sink technique is considered as a good solution to the hotspot problem. Mobile sinks travel physically in the network to collect data directly from special nodes, such as cluster heads (CHs). Find the optimal path for the mobile sink is of utmost importance in order to achieve energy efficiency. The ant colony optimization (ACO) algorithm has been founded to be a good solution to meet this objective. Whereas the traditional ACO algorithm and its versions do not restrict the spread of ants which consumes a lot of energy and makes the convergence speed slow. In this paper, we propose an Intelligent ACO-based Routing Protocol with multiple mobile sinks support for wireless sensor networks (named IARP). This proposed protocol divides the WSN into clusters where each one is managed by a CH. The CH selection is conceived in such a way to use the minimum control overhead and also avoid the greedy re-clustering process. It considers not only pheromone but also remaining energy and hop count heuristic parameters. As well, the scope of ants search is restricted to save a lot of energy. Additionally, we have conceived a fault-tolerant algorithm to resume the normal functionality of the network after the failure of critical nodes i.e. CHs. The proposed protocol is tested by using simulations. The results show that the proposed IARP can significantly improve the performance of WSNs compared to other benchmark protocols.

Real-time data delivery is the most important requirement for mission-critical applications in wireless sensor networks. Since a mobile sink is requested for applications and for energy efficiency in WSNs, an Expect Area-based Real-time Routing protocol (EAR2) is proposed to support real-time routing to the mobile sink. EAR2 is based on an Expect Area (EA) of the mobile sink and exploit flooding of real-time data within EA. However, flooding within EA makes sensor nodes in EA consume much energy. Flooding time within EA may also be difficult to measure and change widely according to time and environment. Thus, to avoid the flooding problems in EAR2, we propose a new real-time routing protocol based on grids for a mobile sink. In addition to EA of a mobile sink, the proposed protocol considers Expect Grids (EGs) of the mobile sink, which are included in EA. Instead of flooding within EA, the proposed protocol exploits multicasting to EGs and one-hop forwarding in a EG because in comparison with flooding, multicasting saves much energy and one-hop forwarding time is easy to measure and changes narrowly according to time and environment. Simulation results show that the proposed protocol is superior to other protocols.

Lifetime and energy efficiency are important factors in the design of wireless sensor network. A critical issue during data collection is the formation of energy holes near the sink. Sensors which are located near the sink have to participate in relaying data on behalf of other sensors and thus their energy will be depleted very quickly. Mobile sink movement yields the significant performance gained by decreasing the amount of energy consumption. In this paper, we propose an Intelligent Grid Based Data Disseminating protocol for mobile sink in wireless sensor networks. We have utilized a virtual grid as the protocol's substructure. In our proposed method, cell heads (CHs) will be selected based on the locations of virtual cross points (CPs) and CPs selection is needless to transfer any required data between neighbor nodes. We have optimized CPs selection using linear programming technique in order to increase network lifetime. By selecting the CHs based on our proposed algorithm, data will be disseminated toward the sink. Our data dissemination protocol is simple and has low overhead to construct and maintain. Also, we have presented a new method for sink location update which leads to the least cost in data transfer. Simulation results illustrate that by utilizing hierarchical functionality and selecting appropriate CPs and consequently selecting CHs, energy consumption will be decreased in comparison with other presented methods which directly lead to network lifetime increment. Also by determining an optimal cell size, packet delivery rate will be improved noticeably.

An efficient networks’ energy consumption and Quality of Services (QoS) are considered the most important issues, to evaluate the route quality of the designed routing protocol in Wireless Sensor Networks (WSNs). This study is presented an evaluation performance technique to evaluate two routing protocols: Secure for Mobile Sink Node location using Dynamic Routing Protocol (SMSNDRP) and routing protocol that used K-means algorithm to form Data Gathered Path (KM-DGP), on small and large network with Group of Mobile Sinks (GMSs). The propose technique is based on QoS and sensor nodes’ energy consumption parameters to assess route quality and networks’ energy usage. The evaluation technique is conducted on two routing protocols in two phases: The first phase is used to evaluate the route quality and networks’ energy consumption on small WSN with one mobile Sink Node (SN) and GMSs. The second phase, is used to evaluate the route quality and networks’ energy consumption on large network (four WSNs) with GMSs. The two phases are implementated by creating five sceneries via using NS2.3 simulator software. The implementation results of the proposed performance evaluation technique have demonstrated that SMSNDRP gives better networks’ energy consumption on small single network in comparison with KM-DGP. Also, it gives high quality route in large network that used four mobile SN, in contrast to KM-DGP that used sixteen mobile SNs. While in large network, it found that KM-DGP with sixteen mobile SNs gives better networks’ energy consumption in comparison with SMSNDRP with four mobile SNs.

In recent years, due to technology development, applying WSNs has increased, and consequently, researchers have developed an interest in dealing with the problems of WSNs. The power-limitation issue of sensor nodes brings a serious challenge for employing WSNs. Clustering has a significant effect on increasing the network lifetime. Also, using mobile sinks is an ideal solution to improve network efficiency and lifetime as well as reducing end-to-end delay. In this study, all nodes are clustered and scored. Next, the nodes with the highest scores are selected as CHs. Then the network is partitioned. Here, mobile sinks have been applied to save the energy of nodes. The movement of the sinks, which are individually appointed to each section, is controlled by two parameters. The proposed method was simulated via MATLAB and was compared with PRD, ETX, EFW and PDX methods. The results revealed an improvement in energy consumption, end-to-end delay, packet delivery rate and the number of alive nodes in the network.