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66
Multicasting in delay tolerant networks: semantic models and routing algorithms.
- Proc. SIGCOMM Workshop on Delay Tolerant Networking,
, 2005
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Achieving real-time target tracking using wireless sensor networks
- In IEEE RTAS 2006
, 2006
"... Target tracking systems need to meet certain real-time constraints in response to transient events, such as fast-moving targets. While the real-time performance is a major concern in these applications, it should be compatible with other important system properties such as energy consumption and acc ..."
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Cited by 59 (5 self)
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Target tracking systems need to meet certain real-time constraints in response to transient events, such as fast-moving targets. While the real-time performance is a major concern in these applications, it should be compatible with other important system properties such as energy consumption and accuracy. This work presents the real-time design and analysis of VigilNet, a large-scale sensor network system which tracks, detects and classifies targets in a timely and energy efficient manner. Based on a deadline partition method and theoretical derivations to guarantee each sub-deadline, we are able to make guided engineering decisions to meet the endto-end tracking deadline. The results from 10,000-node simulation and 200 mote field test reveal the effectiveness of our design.
A scalable logical coordinates framework for routing in wireless sensor networks
- In Proceedings of the 25th Internetional Real-Time Systems Symposium (RTSS 04
"... In this article, we present logical coordinates based routing (LCR), a novel framework for scalable and location-independent routing in wireless sensor networks. LCR assigns each node a logical coor-dinate vector, and routes packets following these vectors. We demonstrate that LCR (i) guarantees pac ..."
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Cited by 56 (2 self)
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In this article, we present logical coordinates based routing (LCR), a novel framework for scalable and location-independent routing in wireless sensor networks. LCR assigns each node a logical coor-dinate vector, and routes packets following these vectors. We demonstrate that LCR (i) guarantees packet delivery with a high probability, (ii) finds good paths, and (iii) exhibits robust performance in the presence of network voids and node failures. We systematically evaluate the performance of LCR through simulations and compare it with other state-of-the-art protocols. We also propose two extensions of LCR, one for three-dimensional node deployments and the other for unreliable wireless links.
Supporting concurrent applications in wireless sensor networks
- In Conference On Embedded Networked Sensor Systems
, 2006
"... It is vital to support concurrent applications sharing a wireless sensor network in order to reduce the deployment and administrative costs, thus increasing the usability and efficiency of the network. We describe Melete 1, a system that supports concurrent applications with efficiency, reliability, ..."
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Cited by 49 (1 self)
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It is vital to support concurrent applications sharing a wireless sensor network in order to reduce the deployment and administrative costs, thus increasing the usability and efficiency of the network. We describe Melete 1, a system that supports concurrent applications with efficiency, reliability, flexibility, programmability, and scalability. Our work is based on the Maté virtual machine [1] with significant modifications and enhancements. Melete enables reliable storage and execution of concurrent applications on a single sensor node. Dynamic grouping is used for flexible, on-the-fly deployment of applications based on contemporary status of the sensor nodes. The grouping procedure itself is programmed with the TinyScript language. A group-keyed code dissemination mechanism is also developed for reliable and efficient code distribution among sensor nodes. Both analytical and simulation results are presented to study the impact of several key parameters and optimization techniques on the code dissemination mechanism. Simulation results indicate satisfactory scalability of our techniques to both application code size and node density. The usefulness and effectiveness of Melete is also validated by empirical study.
Least privilege and privilege deprivation: Towards tolerating mobile sink compromises in wireless sensor networks
- in Proceedings of ACM Mobihoc
, 2005
"... Mobile sinks are needed in many sensor network applications for efficient data collection, data querying, localized sensor reprogramming, identifying, and revoking compromised sensors, and other network maintenance. Employing mobile sinks however raises a new security challenge: if a mobile sink is ..."
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Cited by 46 (3 self)
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Mobile sinks are needed in many sensor network applications for efficient data collection, data querying, localized sensor reprogramming, identifying, and revoking compromised sensors, and other network maintenance. Employing mobile sinks however raises a new security challenge: if a mobile sink is given too many privileges, it will become very attractive for attack and compromise. Using a compromised mobile sink, an adversary may easily bring down or even take over the sensor network. Thus, security mechanisms that can tolerate mobile sink compromises are essential. In this article, based on the principle of least privilege, we first propose an efficient scheme to restrict the privilege of a mobile sink without impeding its ability to carry out any authorized operations for an assigned task. In addition, we present an extension to allow conditional trajectory change due to unexpected events. To further reduce the possible damage caused by a compromised mobile sink, we propose efficient message forwarding schemes for deleting the privilege assigned to a compromised mobile sink immediately after its compromise has been detected. Through detailed
Probabilistic QoS guarantee in reliability and timeliness domains in wireless sensor networks
- in Proc. of the IEEE Infocom
, 2005
"... Abstract — In this paper, we present a novel packet delivery ..."
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Cited by 44 (0 self)
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Abstract — In this paper, we present a novel packet delivery
Opportunistic flooding in low-duty-cycle wireless sensor networks with unreliable links
- in Proc. ACM Int. Conf. Mobile Comput. Netw., 2009
"... ABSTRACT Intended for network-wide dissemination of commands, configurations and code binaries, flooding has been investigated extensively in wireless networks. However, little work has yet been done on low-duty-cycle wireless sensor networks in which nodes stay asleep most of time and wake up asyn ..."
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Cited by 42 (6 self)
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ABSTRACT Intended for network-wide dissemination of commands, configurations and code binaries, flooding has been investigated extensively in wireless networks. However, little work has yet been done on low-duty-cycle wireless sensor networks in which nodes stay asleep most of time and wake up asynchronously. In this type of network, a broadcasting packet is rarely received by multiple nodes simultaneously, a unique constraining feature that makes existing solutions unsuitable. Combined with unreliable links, flooding in low-duty-cycle networks is a new challenging issue. In this paper, we introduce Opportunistic Flooding, a novel design tailored for low-duty-cycle networks with unreliable wireless links and predetermined working schedules. The key idea is to make probabilistic forwarding decisions at a sender based on the delay distribution of next-hop nodes. Only opportunistically early packets are forwarded using links outside the energy optimal tree to reduce the flooding delay and redundancy in transmission. To improve performance further, we propose a forwarder selection method to alleviate the hidden terminal problem and a link-qualitybased backoff method to resolve simultaneous forwarding operations. We evaluate Opportunistic Flooding with extensive simulation and a test-bed implementation consisting of 30 MicaZ nodes. Evaluation shows our design is close to the optimal performance achievable by oracle flooding designs. Compared with improved traditional flooding, our design achieves significantly shorter flooding delay while consuming only 20% ∼ 60% of the transmission energy in various low-duty-cycle network settings.
Mobieyes: A distributed location monitoring service using moving location queries
- IEEE TRANSACTIONS ON MOBILE COMPUTING
, 2006
"... With the growing popularity and availability of mobile communications, our ability to stay connected while on the move is becoming a reality instead of science fiction as it was just a decade ago. An important research challenge for modern location-based services is the scalable processing of locat ..."
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Cited by 40 (2 self)
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With the growing popularity and availability of mobile communications, our ability to stay connected while on the move is becoming a reality instead of science fiction as it was just a decade ago. An important research challenge for modern location-based services is the scalable processing of location monitoring requests on a large collection of mobile objects. The centralized architecture, though studied extensively in literature, would create intolerable performance problems as the number of mobile objects grows significantly. This paper presents a distributed architecture and a suite of optimization techniques for scalable processing of continuously moving location queries. Moving location queries can be viewed as standing location tracking requests that continuously monitor the locations of mobile objects of interest and return a subset of mobile objects when certain conditions are met. We describe the design of MobiEyes, a distributed real time location monitoring system in a mobile environment. The main idea behind the MobiEyes ’ distributed architecture is to promote a careful partition of a real time location monitoring task into an optimal coordination of server-side processing and client-side processing. Such a partition allows evaluating moving location queries with a high degree of precision using a small number of location updates, thus providing highly scalable location monitoring services. A set of optimization techniques are used to limit the amount of computation to be handled by the mobile objects and enhance the overall performance and system utilization of MobiEyes. Important metrics to validate the proposed architecture and optimizations include messaging cost, server load, and amount of computation at individual mobile objects. We evaluate the scalability of the MobiEyes location monitoring approach using a simulation model based on a mobile setup. Our experimental results show that MobiEyes can lead to significant savings in terms of server load and messaging cost when compared to solutions relying on central processing of location information.
RBP: Robust broadcast propagation in wireless networks
- In Sensys’06
, 2006
"... Varying interference levels make broadcasting an unreliable operation in low-power wireless networks. Many routing and resource discovery protocols depend on flooding (repeated per-node broadcasts) over the network. Unreliability at the broadcast-level can result in either incomplete flooding covera ..."
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Cited by 33 (0 self)
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Varying interference levels make broadcasting an unreliable operation in low-power wireless networks. Many routing and resource discovery protocols depend on flooding (repeated per-node broadcasts) over the network. Unreliability at the broadcast-level can result in either incomplete flooding coverage or excessive re-flooding, making path maintenance either unreliable or expensive. We present RBP, a very simple protocol that bolsters the reliability of broadcasting in such networks. Our protocol requires only local information, and resides as a service between the MAC and network layer, taking information from both. We show that RBP improves reliability while balancing energy efficiency. RBP is based on two principles: First, we exploit network density to achieve near-perfect flooding reliability by requiring moderate (50-70%) broadcast reliability when nodes have many neighbors. Second, we identify areas of sparse connectivity where important links bridge dense clusters of nodes, and strive for guaranteed reliability over those links. We demonstrate, through both testbed experiments and controlled simulations, that this hybrid approach is advantageous to providing nearperfect reliability for flooding with good efficiency. Testbed experiments show 99.8 % reliability with 48 % less overhead than the level of flooding required to get equivalent reliability, suggesting that routing protocols will benefit from RBP.
TACO-DTN: A Time-Aware COntent-based dissemination system for Delay Tolerant Networks
- in Proceedings of the First International Workshop on Mobile Opportunistic Networking (Mobiopp), Puerto Rico
, 2007
"... Content dissemination applications are becoming more and more popular on fixed infrastructure: in this paper we introduce TACO-DTN, a content dissemination system which, by virtue of being time-aware in terms of subscriptions and events, is appropriate for delay tolerant networks, where a number of ..."
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Cited by 31 (1 self)
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Content dissemination applications are becoming more and more popular on fixed infrastructure: in this paper we introduce TACO-DTN, a content dissemination system which, by virtue of being time-aware in terms of subscriptions and events, is appropriate for delay tolerant networks, where a number of nodes act as infostations, enjoying some form of connectivity to the backbone, and other nodes are mobile devices, reachable sometimes only through intermittent connectivity of carriers. Examples of applications benefiting from such a system could be travel information dissemination systems in large cities (exploiting infostations at bus stops) or on highways, advertisements dissemination at specific times, and information dissemination to remote villages. The approach is based on a novel concept of temporal utility of subscriptions and events. The temporal utility is used to govern the routing of the events to the right infostation (i.e., the one reached by the interested subscribers at the right time), avoiding unnecessary information transfer on slow links and the buffer management, in case buffer limitations are an issue. We give a description of our protocol and discuss its validation through simulation.
