Security is a fundamental prerequisite for the survivability and reliability of wireless networks. In a network where limited wireless resources have to be shared, selfish nodes can manipulate relevant network paramet...
详细信息
Security is a fundamental prerequisite for the survivability and reliability of wireless networks. In a network where limited wireless resources have to be shared, selfish nodes can manipulate relevant network parameters to gain more access to the resources, and hence obtain a higher performance than their fair share, while the performance of well-behaved nodes will be significantly degraded. this paper considers the environment of an ieee802.11 WLAN, and proposes a solution from the prospective of a principal-agent system. Our solution uses an incentive and a constraint mechanism to encourage the selfish agent to perform normally. Our method does not modify the ieee 802.11 protocol, but requires an additional principal node only. Simulation results show that our method can overcome the influence of selfish nodes improve the network fairness performance while maintaining the throughput performance.
Asymmetric links commonly exist in low power wireless sensor networks. However, it is difficult to discover and exploit them efficiently. In this work, we propose DEAL, a link management scheme to Discover and Exploit...
详细信息
Asymmetric links commonly exist in low power wireless sensor networks. However, it is difficult to discover and exploit them efficiently. In this work, we propose DEAL, a link management scheme to Discover and Exploit Asymmetric Links efficiently in dense wireless sensor networks. Equipped with a novel feedback mechanism, DEAL dynamically adapts its link maintenance mechanism based on the estimated link quality, and manages the (small) neighbor table so as to retain the most useful information. We implement DEAL in TinyOS and evaluate its performance using both TOSSIM and testbed. the simulation results show that more than 80% of asymmetric links can be discovered and maintained with minimum overhead. Using a collection tree application and ETX as the routing metric, the average path ETX can be reduced by up to 20%. Testbed evaluation also shows that DEAL improves the network routing performance by identifying useful asymmetric links.
this demo presents a mobile wireless sensor system for debris flow monitoring. the objective of this system is to realize long-term and effective debris flow surveillance using low cost wireless sensors. In the system...
详细信息
this demo presents a mobile wireless sensor system for debris flow monitoring. the objective of this system is to realize long-term and effective debris flow surveillance using low cost wireless sensors. In the system, a set of robust wireless sensors are designed to deploy on riverbed and cooperatively observe the moving debris flows. Our mobile sensors are intended to be carried along by the debris flow. As the sensors move along, they are able to measure the internal parameters, such as vibration frequency, amplitude, moving direction and velocity, of the debris flow. By utilizing the proposed energy-saving mechanism on the WSN platform, the mobile sensors can continuously operate up to six months with merely two alkaline D cell batteries. the proposed system provides the abilities to collect high-fidelity data for civil engineering applications to analyze and determine the occurrence of debris flows, as well as estimate the damage.
Wireless sensor networks are going to allow for ubiquitous health monitoring, improving users' well-being, the healthcare system, and helping to quickly react on emergency situations. Meeting the strict security n...
详细信息
Wireless sensor networks are going to allow for ubiquitous health monitoring, improving users' well-being, the healthcare system, and helping to quickly react on emergency situations. Meeting the strict security needs of these ubiquitous medical applications is a big challenge, since safety and privacy of medical data has to be guaranteed all the way from the sensor nodes to the back-end services, the system has to fulfill latency needs, and lots of mobility is expected. In this paper, we introduce a deployment model for wireless sensor networks for pervasive healthcare based on the concepts of patient area networks and medical sensor networks, and propose a complete and efficient security framework for them. Our security framework is organized into three layers, addressing the operational requirements and security needs at the patient area network, medical sensor network and back-end levels. We specify how these layers are interconnected with each other as well as the needed security mechanisms that allow for the efficient and practical deployment of secure pervasive healthcare systems based on wireless sensor networks.
Investigation of components and their interaction in operation is especially important for the design of systems using ambient energy. the limited energy harvester's efficiency, the strong fluctuating behaviour of...
详细信息
Investigation of components and their interaction in operation is especially important for the design of systems using ambient energy. the limited energy harvester's efficiency, the strong fluctuating behaviour of the ambient energy sources as well as the limited storage unit's capacities command the actual performance of such systems. In order to design energy autonomous systems an automated test platform has been developed, to characterise energy harvesting systems at component and system level. Different energy harvester and system components have been investigated and their interaction with each other has been evaluated. Using the developed test platform, the efficiency of energy conversion and energy management can be investigated thoroughly.
Recent study reveals that great benefit can be achieved for data gathering in wireless sensor networks by employing mobile collectors that gather the data via short-range communications. To pursue maximum energy savin...
详细信息
ISBN:
(纸本)9781424451142
Recent study reveals that great benefit can be achieved for data gathering in wireless sensor networks by employing mobile collectors that gather the data via short-range communications. To pursue maximum energy saving at sensor nodes, intuitively, a mobile collector should traverse the transmission range of each sensor in the field such that the transmission of each packet can be constrained to a single hop. However, this approach may lead to significantly increased data collection latency due to the low moving velocity of the mobile collector. On the other hand, data collection latency can be effectively shortened by performing local aggregation via multi-hop transmissions and then uploading the packets from relay sensors to the mobile collector. However, local transmission hops should not be arbitrarily increased since it may incur too much energy consumption on packet relays, which would adversely affect the overall efficiency of mobile data collection. Based on these observations, in this paper, we study the tradeoff between energy saving and data collection latency in mobile data gathering by exploring a balance between the relay hop count of local data aggregation and the moving tour length of the mobile collector. We first propose a polling-based mobile collection approach and formulate it into an optimization problem, named bounded relay hop mobile data collection (BRH-MDC). Specifically, a subset of sensors will be selected as polling points that buffer locally aggregated data and upload the data to the mobile collector when it arrives. In the meanwhile, when sensors are affiliated withthese polling points, it is guaranteed that any packet relay is bounded within a given number of hops. We then give two efficient algorithms to select polling points among sensors. the effectiveness of our approach is validated through extensive simulations.
Wireless sensor networks are going to allow for ubiquitous health monitoring, improving users' well-being, making the healthcare system more efficient, and helping to quickly react on emergency situations. Meeting...
详细信息
Wireless sensor networks are going to allow for ubiquitous health monitoring, improving users' well-being, making the healthcare system more efficient, and helping to quickly react on emergency situations. Meeting the strict security needs of ubiquitous medical applications is a big challenge: safety and privacy of patient data has to be guaranteed all the way from the sensor nodes to the back-end services, the system has to fulfill latency needs, and lots of mobility is expected. In this paper, we introduce a deployment model for wireless sensor networks for pervasive healthcare based on the concepts of patient area and medical sensor networks. We propose a complete and efficient security framework organized into three layers, addressing the operational requirements and security needs at the patient area network, medical sensor network, and back-end levels. We specify how these layers are interconnected with each other as well as the needed security and privacy mechanisms that allow for the efficient and practical deployment of secure pervasive healthcare systems based on wireless sensor networks.
there is a growing need for enabling reprogramming in a working sensor network. We prefer to meet the requirements remotely instead of collecting all deployed sensors. Identifying the version difference of data items,...
详细信息
ISBN:
(纸本)9781424451142
there is a growing need for enabling reprogramming in a working sensor network. We prefer to meet the requirements remotely instead of collecting all deployed sensors. Identifying the version difference of data items, having the same key, could significantly reduce the communication overhead, because only those out-of-date items should be updated at each sensor. Previous protocols need to exchange multiple messages to identify a version difference between two items withthe same key. In this paper, we propose a reliable and energy efficient data dissemination protocol (BDP) with less propagation delay. BDP uses Bloom filters to identify a version difference between two items withthe same key, and find the new one between two items having the same key but different versions. through comprehensive simulations, we show that BDP outperforms previous work in terms of energy cost and propagation delay of updating new items with high reliability.
Broadcast of information in wireless sensor networks is an important operation, e.g., for code updates, queries, membership information, etc. In this paper, we analyze and experimentally compare the performance of van...
详细信息
Broadcast of information in wireless sensor networks is an important operation, e.g., for code updates, queries, membership information, etc. In this paper, we analyze and experimentally compare the performance of vanilla versions of several well-known broadcast mechanisms namely, flooding, site percolation, bond percolation, and modified bond percolation. We carry out our comparison for different network topologies: random, grid, and clustered. Our analysis is performed at the link layer level using a MAC-independent propagation model based on real experiments from the literature. Our main metrics are bandwidth, energy usage, and broadcast latency. Our analytical and experimental results show that, given a desired high reliability for all topologies, flooding and site percolation has the lowest latency; but flooding consumes the most energy per broadcast compared to site percolation. For dense networks, modified bond percolation further lowers energy consumption compared to site percolation, while basic bond percolation leads to a latency increase. For sparse networks, results are similar to a dense network except that site percolation consumes lower energy than modified bond percolation. We briefly discuss implications for different broadcast applications.
there is a growing consensus that the great risks arising from climate change require strong cuts of greenhouse gas emissions and that actions are urgently needed. the current economic crisis force policy makers to re...
详细信息
there is a growing consensus that the great risks arising from climate change require strong cuts of greenhouse gas emissions and that actions are urgently needed. the current economic crisis force policy makers to reconsider their policies and to introduce reforms that foster enhanced efficiency and more sustainable long term growth. Within this context, this paper assesses, by means of a scenario analysis, the impact of the distributed generation in the Italian power system, in terms of both economic and environmental costs and benefits. In particular, a baseline scenario, characterized by a development of renewable energy sources, is compared with other scenarios characterized by an increasing penetration of small combined heat and power plants, till to saturate an estimated potential in the industrial, tertiary and residential sectors.
暂无评论