Content uploaded by Nikos Dimokas
Author content
All content in this area was uploaded by Nikos Dimokas on Nov 12, 2014
Content may be subject to copyright.
A preview of the PDF is not available
Detecting Energy-Efficient Central Nodes for Cooperative Caching in Wireless Sensor Networks
Abstract and Figures
The deployment of wireless sensor networks in many application areas like environment control, target tracking in battlefields, requires an optimization to the communication among the sensors so as to serve data in short latency and with minimal energy consumption. Cooperative data caching has been proposed as an effective and efficient technique to achieve these goals concurrently. The design of protocols for such networks depends mainly on the selection of the sensors which will take special roles in coordinating the procedure of caching and take forwarding decisions. This article introduces a new metric to aid in the selection of such nodes. Based on this metric, we propose a new energy efficient cooperative caching protocol, which is compared against the state-of-the-art competing protocol. The simulation results attest the superiority of the proposed protocol.
Figures - uploaded by Nikos Dimokas
Author content
All figure content in this area was uploaded by Nikos Dimokas
Content may be subject to copyright.
... The DC is called "undirected degree centrality" or just "degree centrality." The more the network is connected reaching mesh connection with higher nodes' degree centrality, the stronger the response for any node failure action [29]. The nodes with high DC are wrongly expected to be having better connection inside the network. ...
... That is done through measuring the inverse of sum of the shortest distance (the geodesic distance) between the measured node and the rest of nodes [23,30]. That gives a description for information flow efficiency between nodes; in other words it estimates the time required to information to be spread through the network [29]. The formula that represents the closeness centrality metric is: ...
The application of wireless sensor networks is widely spread through the last years as it is well known in many fields and multiple applications. Localization of nodes within wireless sensor networks is one of the important topics in studying and managing these networks. The presented new localization technique combines the received signal strength indicator method which limits the communications between nodes to the range of accessible radiated signal, with a new trend which is social network analysis that deals with relationships between nodes in any network with metrics and layouts. By using mixed metric between degree and closeness, we will maintain the suitable elected seeds that will be anchors for around nodes inside the network. Trilateration calculations will be applied between optimized elected nodes with higher centrality to localize the target nodes.
... A load balancing adaptive video scheme is discussed [28]. The author presented the cooperative caching [29] scheme using scheduling in which partial sensor node sleep with its ranging and others active to serve the request. A caching scheme is presented based on data lifetime, and the request rate [30] to reduce the delay in the network. ...
Nowadays, Internet usage has become prevalent, primarily because of high-quality heterogeneous multimedia content expectations from the subscriber (consumer), which puts tremendous pressure on the publisher (producer) in the networks. Information-Centric Networking (ICN) is a future internet architecture that optimizes data resources through content-based forwarding and caching, making it well-suited for multimedia content and video streaming (VS) scenarios. However, real-time data delivery is challenging in the current ICN-based publish–subscribe (pub-sub) mechanism, which pushes the existing pub-sub studies to prioritize more on the forwarding information base (FIB) rather than the pending interest table (PIT). This leads to issues such as inefficient caching and forwarding mechanisms, high overhead, and communication costs. To address these challenges, in this paper, we present a novel forwarding and caching solution named VS-ICSDN, integrating the combined principles of ICN-based pub-sub scheme and software-defined networking (SDN) in order to utilize the network resources more efficiently. We design a clean-slate caching strategy and name-based forwarding method to support both on-path and off-path caching on ICN nodes to coordinate flow entries among the SDN controller and clean-slate ICN nodes to maximize PIT utilization. In addition, the framework allows the content to be stored and searched in chunks with a single request to access the desired content, reducing the communication overhead and significantly improving overall performance. A simulation-based testbed and experimental result analysis validate our proposed work’s effectiveness in ensuring efficient network resource usage with low communication overhead and computational cost compared to other baseline methods.
... While other estimates of the importance of sensors relative to the network topology and the remaining energy. The intuition is that if it discovers those nodes, which have enough remaining energy and resides in a significant part of the (short) paths connecting other nodes [41]. Figure 8 summarizes the cache decision policies used by different cache-based transport protocols. ...
Sensor nodes in Wireless Sensor Networks (WSNs) are battery-powered devices that consume energy during data transmission and processing. One of the most critical tasks in a sensor network is dealing with reliable end-to-end transmissions and optimizing the power consumption. WSNs are error prone due to the constrained nature of the nodes and the interference with other wireless technologies such as Wifi and Bluetooth. One possible way to minimize this problem is caching the data. Data caching is one technique of improving the performance of a transport protocol. Since a typical data transmission consumes more energy than processing in a sensor network, the use of caching enables quick access to data. Therefore, caching, if used efficiently, could reduce overall network traffic and hence bandwidth can be optimally utilized. Unfortunately, a systematic analysis of caching in WSNs was until now lacking. Given that WSNs are expected to play an important role in Machine Type Communications (MTC) and Internet of Things (IoT), the authors believe that now is time to collect the results of years of research on this important topic. This paper presents a comprehensive survey on the state-of-the-art cache-based transport protocols in wireless sensor networks. We classify the transport protocols by presenting a thematic taxonomy of the current cache management mechanisms in wireless sensor networks. Moreover, the critical aspects of the existing cache-ware schemes in sensor networks are analyzed to determine the strengths and weaknesses of such protocols. The similarities and differences of the transport protocols based on the important parameters, such as cache insertion/replacement policy, cache size requirement, cache location, cache partition, and cache decision are investigated in this paper. In addition to that, we discuss open research issues and challenges of cache-based transport protocols in wireless sensor networks. We strongly believe that this study can serve as a basis so that future implementations can choose the combination of caching mechanisms that best fits their target application scenario.
The system lifetime can be amplified if the correspondence between sensor hubs in the WSN is diminished. Reserving the information close to the asking for hub will be useful to decrease the information access idleness and correspondence overhead; in this manner system lifetime will be expanded. Store hub is especially difficult when every hub of system has a constrained memory to reserve. Select the hubs that can go about as reserves and settle on solicitation sending choices and afterward we perform ideal arrangement of these store hubs in remote sensor arrange .The current methodology utilization of a multi objective hereditary calculation for reserve hub situation in remote sensor system (WSN). In this methodology GA effectively helps in selecting sensor hubs to actualize reserving and appeal sending choice .Our proposed plan is Elitism based Genetic Algorithm (EBGA), which will be select just best arrangement and dispense with the most exceedingly terrible arrangement. By utilizing EBGA the execution would be enhanced than existing approach and system life time increment. Time utilization in system for the information transforming is likewise lessened. The average latency or end to end delay d by 7.33% and packet delivery ratio in the network by 5.55%.
The system lifetime can be amplified if the correspondence between sensor hubs in the WSN is diminished. Reserving the information close to the asking for hub will be useful to decrease the information access idleness and correspondence overhead; in this manner system lifetime will be expanded. Store hub is especially difficult when every hub of system has a constrained memory to reserve. Select the hubs that can go about as reserves and settle on solicitation sending choices and afterward we perform ideal arrangement of these store hubs in remote sensor arrange .The current methodology utilization of a multi objective hereditary calculation for reserve hub situation in remote sensor system (WSN). In this methodology GA effectively helps in selecting sensor hubs to actualize reserving and appeal sending choice .Our proposed plan is Elitism based Genetic Algorithm (EBGA), which will be select just best arrangement and dispense with the most exceedingly terrible arrangement. By utilizing EBGA the execution would be enhanced than existing approach and system life time increment. Time utilization in system for the information transforming is likewise lessened. The average latency or end to end delay d by 7.33% and packet delivery ratio in the network by 5.55%.
The system lifetime can be amplified if the correspondence between sensor hubs in the WSN is diminished. Reserving the information close to the asking for hub will be useful to decrease the information access idleness and correspondence overhead; in this manner system lifetime will be expanded. Store hub is especially difficult when every hub of system has a constrained memory to reserve. Select the hubs that can go about as reserves and settle on solicitation sending choices and afterward we perform ideal arrangement of these store hubs in remote sensor arrange .The current methodology utilization of a multi objective hereditary calculation for reserve hub situation in remote sensor system (WSN). In this methodology GA effectively helps in selecting sensor hubs to actualize reserving and appeal sending choice .Our proposed plan is Elitism based Genetic Algorithm (EBGA), which will be select just best arrangement and dispense with the most exceedingly terrible arrangement. By utilizing EBGA the execution would be enhanced than existing approach and system life time increment. Time utilization in system for the information transforming is likewise lessened. The average latency or end to end delay d by 7.33% and packet delivery ratio in the network by 5.55%.
The system lifetime can be amplified if the correspondence between sensor hubs in the WSN is diminished. Reserving the information close to the asking for hub will be useful to decrease the information access idleness and correspondence overhead; in this manner system lifetime will be expanded. Store hub is especially difficult when every hub of system has a constrained memory to reserve. Select the hubs that can go about as reserves and settle on solicitation sending choices and afterward we perform ideal arrangement of these store hubs in remote sensor arrange .The current methodology utilization of a multi objective hereditary calculation for reserve hub situation in remote sensor system (WSN). In this methodology GA effectively helps in selecting sensor hubs to actualize reserving and appeal sending choice .Our proposed plan is Elitism based Genetic Algorithm (EBGA), which will be select just best arrangement and dispense with the most exceedingly terrible arrangement. By utilizing EBGA the execution would be enhanced than existing approach and system life time increment. Time utilization in system for the information transforming is likewise lessened. The average latency or end to end delay d by 7.33% and packet delivery ratio in the network by 5.55%.
Hosting multiple applications in a shared infrastructure of wireless sensor networks is a trend nowadays, and sharing sensory data for answering concurrent applications is a promising and energy-efficient strategy. To address this challenge, this paper proposes an energy-efficient query optimization mechanism for supporting multiple concurrent applications leveraging our two-tier cooperative caching mechanism. Specifically, query requests for concurrent applications are represented as binary strings, which are reduced to a single one for avoiding the reprocessing of shared subquery requests. This reduced query request is answered through our cooperative caching mechanism, where sensory data, which are highly possible to be reused for answering forthcoming query requests, are cached at the sink node (SN). Besides, the gray model GM(1, 1) is adopted for forecasting sensory data units which may be interested mostly by forthcoming query requests. These units of sensory data may be prefetched from the network and cached at the SN. Experimental evaluation shows that this approach can reduce the energy consumption significantly, and improve the network capacity to an extent, especially when the number of concurrent query requests is relatively large.
The recent advances in miniaturization and the creation of low-power circuits, combined with small-sized batteries have made
the development of wireless sensor networks a working reality. Lately, the production of cheap complementary metal-oxide semiconductor
cameras and microphones, which are able to capture rich multimedia content, gave birth to what is called Wireless Multimedia Sensor Networks (WMSNs). WMSNs will boost the capabilities of current wireless sensor networks, and will fuel several novel applications, like multimedia
surveillance sensor networks. WMSNs introduce several new research challenges, mainly related to mechanisms to deliver application-level
Quality-of-Service (e.g., latency minimization). To address this goal in an environment with extreme resource constraints,
with variable channel capacity and with requirements for multimedia in-network processing, the caching of multimedia data,
exploiting the cooperation among sensor nodes is vital. This article presents a cooperative caching solution particularly
suitable for WMSNs. The proposed caching solution exploits sensor nodes which reside in “positions” of the network that allow
them to forward packets or communicate decisions within short latency. These so-called “mediator” nodes are selected dynamically,
so as to avoid the creation of hot-spots in the communication and the depletion of their energy. The mediators are not more
powerful than the rest of the nodes, but they have some special role in implementing the cooperation among the sensors. The
proposed cooperative caching protocol includes components for locating cached data as well as for implementing data purging
out of the sensor caches. The proposed solution is evaluated extensively in an advanced simulation environment, and it is
compared to the state-of-the-art cooperative caching algorithm for mobile ad hoc networks. The results confirm that the proposed
caching mechanism prevails over its competitor.
In many scenarios, data generated at sensor nodes in wireless sensor networks must be stored temporarily in a network for subsequent use. An individual sensor node's storage capacity is too small to hold it and may soon overflow. Therefore, we propose an effective caching strategy based on cooperation among various sensor nodes to form a larger cumulative cache. As part of the complete caching scheme, a novel token-based cache admission control scheme is devised, which ensures proximity of cached data closer to sink(s). A cache discovery mechanism to efficiently fetch a copy of data items is developed. A single-copy cache coherency scheme is developed to avoid sink from fetching stale data and also avoids undesired data replication. Further, a least utility based item-replacement policy is developed to evict data items with the least utility in case of desired replacement. Simulation results show significant improvements in network energy savings and data availability when cooperative caching is used.
This paper introduces cooperative caching policies for minimizing electronic content provisioning cost in Social Wireless Networks (SWNET). SWNETs are formed by mobile devices, such as data enabled phones, electronic book readers etc., sharing common interests in electronic content, and physically gathering together in public places. Electronic object caching in such SWNETs are shown to be able to reduce the content provisioning cost which depends heavily on the service and pricing dependences among various stakeholders including content providers (CP), network service providers, and End Consumers (EC). Drawing motivation from Amazon's Kindle electronic book delivery business, this paper develops practical network, service, and pricing models which are then used for creating two object caching strategies for minimizing content provisioning costs in networks with homogenous and heterogeneous object demands. The paper constructs analytical and simulation models for analyzing the proposed caching strategies in the presence of selfish users that deviate from network-wide cost-optimal policies. It also reports results from an Android phone-based prototype SWNET, validating the presented analytical and simulation results.
2In an influential paper, Freeman (1979) identified three aspects of centrality: betweenness, nearness, and degree. Perhaps because they are designed to apply to networks in which relations are binary valued (they exist or they do not), these types of centrality have not been used in interlocking directorate research, which has almost exclusively used formula (2) below to compute centrality. Conceptually, this measure, of which c(ot, 3) is a generalization, is closest to being a nearness measure when 3 is positive. In any case, there is no discrepancy between the measures for the four networks whose analysis forms the heart of this paper. The rank orderings by the
Detection of community structures in social networks has attracted lots of attention in the domain of sociology and behavioral
sciences. Social networks also exhibit dynamic nature as these networks change continuously with the passage of time. Social
networks might also present a hierarchical structure led by individuals who play important roles in a society such as managers
and decision makers. Detection and visualization of these networks that are changing over time is a challenging problem where
communities change as a function of events taking place in the society and the role people play in it. In this paper, we address
these issues by presenting a system to analyze dynamic social networks. The proposed system is based on dynamic graph discretization
and graph clustering. The system allows detection of major structural changes taking place in social communities over time
and reveals hierarchies by identifying influential people in social networks. We use two different data sets for the empirical
evaluation and observe that our system helps to discover interesting facts about the social and hierarchical structures present
in these social networks.
KeywordsDynamic social networks–Dynamic network visualization–Clustering dynamic graphs–Influence hierarchy in social networks
Data caching on mobile clients is widely seen as an effective solution to improve system performance. In particular, cooperative caching, based on the idea of sharing and coordination of cache data among multiple users, can be particularly effective for information access in mobile ad hoc networks where mobile clients moving frequently and network topology changing dynamically. Most existing cache strategies perform replacement independently, and they seldom consider coordinated replacement and energy saving issues in the context of a mobile ad hoc network. This paper analysed the impact of energy on designing a cache replacement policy and formulate the energy-efficient coordinated cache replacement problem (ECORP) as a 0-1 knapsack problem. A heuristic algorithm called ECORP-greedy and an optimal solution called ECORP-OPT are presented to solve the problem. Simulations show that the proposed policies can significantly reduce energy consumption and access latency when compared to other replacement policies.
The intuitive background for measures of structural centrality in social networks is reviewed and existing measures are evaluated in terms of their consistency with intuitions and their interpretability.Three distinct intuitive conceptions of centrality are uncovered and existing measures are refined to embody these conceptions. Three measures are developed for each concept, one absolute and one relative measure of the centrality of positions in a network, and one reflecting the degree of centralization of the entire network. The implications of these measures for the experimental study of small groups is examined.
Despite the pervasiveness of networks as models for real world systems ranging from the Internet, the World Wide Web to gene regulation and scientific collaborations, only a limited number of metrics capable of characterizing these systems are available. The existing metrics for characterizing networks have broad specificity and lack the selectivity for many applications. The purpose of this paper is to identify and critically evaluate a metric, termed bridging centrality, which is highly selective for identifying bridges in networks. The properties of bridges are unique compared to the other network metrics. For a diverse range of data sets, we found that networks are highly susceptible to disruption but robust to loss structural integrity upon targeted deletion of bridging nodes. A novel graph clustering approach, termed `bridge cut', utilizing bridging edges as module boundary is also proposed. The modules identified by the bridge cut algorithm are more effective than the other graph clustering methods. Thus, bridging centrality is a network metric with unique properties that may aid in network analysis from element to group level in various areas including systems biology and national security applications.