Advances in wireless networks, mobile devices and location tracking mechanisms are making location-aware applications more and more popular. While several prefetching schemes were proposed for mobile systems, very few...
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ISBN:
(纸本)0769525539
Advances in wireless networks, mobile devices and location tracking mechanisms are making location-aware applications more and more popular. While several prefetching schemes were proposed for mobile systems, very few ones exist for location-dependent applications. And at the best of our knowledge, there is no work describing implementation details of a prefetching scheme for location-dependent systems. In this paper, after a brief survey of information hoarding and prefetching mechanisms, we deduce some requirements for a successful prefetching scheme for location-aware applications, we show that the prefetching policy we previously proposed satisfies these requirements, and we describe a prototype implementing this policy. We describe the system architecture and detailed algorithms describing the tasks executed in the client and the server. We also discuss some additional steps that can be useful for saving energy consumption in the mobile device. An adequate data structure allows the server to have continuously an up to date image of the client's cache content.
MPLS fast reroute (MPLS-FRR) mechanisms deviate the traffic in case of network failures at the router closest to the outage location to achieve an extremely fast reaction time. We review the one-to-one backup and the ...
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ISBN:
(纸本)9781424404247
MPLS fast reroute (MPLS-FRR) mechanisms deviate the traffic in case of network failures at the router closest to the outage location to achieve an extremely fast reaction time. We review the one-to-one backup and the facility backup that are options for MPLS-FRR to deviate the traffic via a detour or a bypass around the failed elements, respectively. Basically, the backup paths can take the shortest path that avoids the outage location from the point of local repair to the tail-end router or to the merge point with the primary path. We suggest two simple modifications that lead to a new path layout which can be implemented by one-to-one and by facility backup. We evaluate the backup capacity requirements, the length of the backup paths, and the number of backup paths per primary path in a parametric study regarding the network characteristics. Our proposals save a considerable amount of backup capacity compared to the standard mechanisms. They are suitable for application in practice since they are simple and conform to the standards.
Without congestion control techniques specifically designed for sensor network applications, the system may not function properly due to data transmission failure. Moreover, most many-to-one communication schemes adop...
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ISBN:
(纸本)3540380914
Without congestion control techniques specifically designed for sensor network applications, the system may not function properly due to data transmission failure. Moreover, most many-to-one communication schemes adopted by sensor network applications cause a practical congestion problem called the funneling effect. With this problem, the hottest area is confined to the connection between the sink and its neighbors. In order to solve the bottleneck problem, we propose a congestion-control technique which uses adaptive time-slot scheduling and a service-differentiated technique. The simulation results show that the proposed method outperforms the conventional technique.
We consider the problem of data propagation in wireless sensor networks and revisit the family of mixed strategy routing schemes. We show that maximizing the lifespan, balancing the energy among individual sensors and...
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Secure key establishment in wireless sensor networks has been shown to be efficient. For sake of computation power, predistribution of symmetric keys is recommended. In such schemes, a set S of keys is used and each d...
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ISBN:
(纸本)3540380914
Secure key establishment in wireless sensor networks has been shown to be efficient. For sake of computation power, predistribution of symmetric keys is recommended. In such schemes, a set S of keys is used and each deployed node knows a subset of S. However, the capture of nodes can quickly lead to the corruption of a significant part of the network and solutions like multi-deployment have been proposed. In multi-deployment schemes, sets of nodes - using different key sets - are sequentially deployed that limits the impact of the capture of nodes. In this paper, we consider the problem of connectivity of single deployment in regards to the size of key sets. We show that connectivity guaranteed solutions lead to network vulnerability when nodes are captured. Then we evaluate network robustness of different schemes.
Data aggregation in Wireless sensor Networks (WSNs) has attracted wide attention since it could reduce the amount of wireless data communication and thus save power consumption, which is one of the top concerns in low...
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ISBN:
(纸本)0769524974
Data aggregation in Wireless sensor Networks (WSNs) has attracted wide attention since it could reduce the amount of wireless data communication and thus save power consumption, which is one of the top concerns in low-power WSN systems. Given a Data Aggregation Tree (DAT) for data query purpose in a WSN, and the expected query accuracy, we show the feasibility to use a low-cost timing control scheme to adaptively adjust the waiting period in each DAT level so that the end-to-end query delay could be optimized, i.e. without unnecessary pause in an aggregation node. For such an adaptive timing control scheme, we propose to use a Finite State Machine (FSM)-based auto-feedback control algorithm to adjust the waiting period of each DAT node to "timely" respond to the queries. Our sensor network simulation results and hardware experiments verify the validity of our proposed timing control scheme.
In wireless sensor networks, it is important to efficiently disseminate information from each source to a sink node. In particular, in mobile sink applications, due to the sink mobility, a stationary dissemination pat...
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ISBN:
(纸本)3540380914
In wireless sensor networks, it is important to efficiently disseminate information from each source to a sink node. In particular, in mobile sink applications, due to the sink mobility, a stationary dissemination path may no longer be effective. The path will have to be continuously reconfigured according to the current location of the sink. In this paper, an Adaptive Reversal Tree (ART) protocol, based on the Adaptive Reversal algorithm and dynamic Root change mechanism, is proposed. Data dissemination from each source to a mobile sink can be easily achieved along the ART without additional control overhead, because the ART proactively performs adaptive sink mobility management. In addition, the ART can maintain a robust tree structure by quickly recovering the partitioned tree with minimum packet transmission. Finally, the simulation results demonstrate that the ART is a considerably energy-efficient and robust protocol.
In this paper we introduce OPSENET, a novel and efficient protocol that facilitates secure routing in directional optical sensor networks. We show that even though the uni-directionality of links in an optical sensor ...
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ISBN:
(纸本)9781424404247
In this paper we introduce OPSENET, a novel and efficient protocol that facilitates secure routing in directional optical sensor networks. We show that even though the uni-directionality of links in an optical sensor network (OSN) complicates the design of efficient routing, link directionality actually helps security in our network setup. In particular, we leverage the naturally-occurring clustering that results from passive (bi-directional) communication of select cluster head nodes with the base station, to improve overall network performance. This paper presents two main contributions: (1) We introduce OPSENET, a novel secure cluster-based routing algorithm for base station circuit discovery in OSNs. In order to support the efficient utilization of a nodes' resources, we employ symmetric cryptography in the design of OPSENET, using efficient one-way hash functions and pre-deployed keying. OPSENET achieves base station broadcast authentication, per-hop authentication, and cluster group secrecy, without requiring any time synchronization. (2) We analyze the relevance of traditional routing attacks on OSNs, and show that OPSENET is robust against uncoordinated (non-smart) insider routing attacks, amongst other compromises. An important performance metric of OPSENET is its low byte overhead, and graceful degradation with the number of compromised nodes in the network. To the best of our knowledge, this is the first paper to consider secure routing in an OSN network scenario.
Wireless sensor network (WSN) is a new trend of the future technology. Noble features of WSNs make them applicable to a variety of applications such as real time tracking of objects, monitoring of environmental condit...
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ISBN:
(纸本)9781424403394
Wireless sensor network (WSN) is a new trend of the future technology. Noble features of WSNs make them applicable to a variety of applications such as real time tracking of objects, monitoring of environmental conditions, monitoring of health structures, and preparing a ubiquitous computing environment. In this paper, we propose to deploy some redundant nodes altogether with main nodes of the network before the network startup phase. These randomly deployed nodes can be used for two purposes. They can either act as helpers to highly loaded nodes for relaying the traffic or replace the dead nodes for sensing and relaying purposes. This scheme allows the network to make use of the additional nodes according to the requirements of the network. The main strategy is to use spare nodes whenever needed. The main advantage of our method is in reducing the time of deploying additional nodes and also the time of utilizing them. This time reduction improves the efficiency of energy consumption.
In this paper, on the basis of end-to-end principle, we propose a mobility management scheme to solve the NAT issue. Furthermore, since different communication technologies own different characteristics, during a vert...
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ISBN:
(纸本)1424402379
In this paper, on the basis of end-to-end principle, we propose a mobility management scheme to solve the NAT issue. Furthermore, since different communication technologies own different characteristics, during a vertical handoff, a wellbehaved mobility management system should adapt an ongoing connection to different communication systems. In this paper, we also propose a handoff-aware TCP adaptation scheme, called CWNDrestore. To verb the feasibility of our approach, we implement a prototype system on Linux. The experimental results show that our mobility management scheme can work under various mobility cases. Furthermore, our proposed CWNDrestore scheme can offer higher TCP throughput during a vertical handoff. For example, the TCP throughput by proposed adaptation scheme is at most 2.3 times the original TCP.
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