Current Search:  Computer networks -- Reliability (x)

View All Items

  • CSV Spreadsheet
(1 - 3 of 3)
Probabilistic predictor-based routing in disruption-tolerant networks
Title
Probabilistic predictor-based routing in disruption-tolerant networks.
Creator
Yuan, Quan., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
Disruption-Tolerant Networks (DTNs) are the networks comprised of a set of wireless nodes, and they experience unstable connectivity and frequent connection disruption because of the limitations of radio range, power, network density, device failure, and noise. DTNs are characterized by their lack of infrastructure, device limitation, and intermittent connectivity. Such characteristics make conventional wireless network routing protocols fail, as they are designed with the assumption the...
Show moreDisruption-Tolerant Networks (DTNs) are the networks comprised of a set of wireless nodes, and they experience unstable connectivity and frequent connection disruption because of the limitations of radio range, power, network density, device failure, and noise. DTNs are characterized by their lack of infrastructure, device limitation, and intermittent connectivity. Such characteristics make conventional wireless network routing protocols fail, as they are designed with the assumption the network stays connected. Thus, routing in DTNs becomes a challenging problem, due to the temporal scheduling element in a dynamic topology. One of the solutions is prediction-based, where nodes mobility is estimated with a history of observations. Then, the decision of forwarding messages during data delivery can be made with that predicted information. Current prediction-based routing protocols can be divided into two sub-categories in terms of that whether they are probability related: probabilistic and non-probabilistic. This dissertation focuses on the probabilistic prediction-based (PPB) routing schemes in DTNs. We find that most of these protocols are designed for a specified topology or scenario. So almost every protocol has some drawbacks when applied to a different scenario. Because every scenario has its own particular features, there could hardly exist a universal protocol which can suit all of the DTN scenarios. Based on the above motivation, we investigate and divide the current DTNs scenarios into three categories: Voronoi-based, landmark-based, and random moving DTNs. For each category, we design and implement a corresponding PPB routing protocol for either basic routing or a specified application with considering its unique features., Specifically, we introduce a Predict and Relay routing protocol for Voronoi-based DTNs, present a single-copy and a multi-copy PPB routing protocol for landmark-based DTNs, and propose DRIP, a dynamic Voronoi region-based publish/subscribe protocol, to adapt publish/subscribe systems to random moving DTNs. New concepts, approaches, and algorithms are introduced during our work.
Show less
Date Issued
2009
PURL
http://purl.flvc.org/FAU/359928
Subject Headings
Routers (Computer networks), Computer network protocols, Computer networks, Reliability, Computer algorithms, Wireless communication systems, Technological innovations
Format
Document (PDF)
Design and implementation of efficient routing protocols in delay tolerant networks
Title
Design and implementation of efficient routing protocols in delay tolerant networks.
Creator
Liu, Cong., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
Delay tolerant networks (DTNs) are occasionally-connected networks that may suffer from frequent partitions. DTNs provide service despite long end to end delays or infrequent connectivity. One fundamental problem in DTNs is routing messages from their source to their destination. DTNs differ from the Internet in that disconnections are the norm instead of the exception. Representative DTNs include sensor-based networks using scheduled intermittent connectivity, terrestrial wireless networks...
Show moreDelay tolerant networks (DTNs) are occasionally-connected networks that may suffer from frequent partitions. DTNs provide service despite long end to end delays or infrequent connectivity. One fundamental problem in DTNs is routing messages from their source to their destination. DTNs differ from the Internet in that disconnections are the norm instead of the exception. Representative DTNs include sensor-based networks using scheduled intermittent connectivity, terrestrial wireless networks that cannot ordinarily maintain end-to-end connectivity, satellite networks with moderate delays and periodic connectivity, underwater acoustic networks with moderate delays and frequent interruptions due to environmental factors, and vehicular networks with cyclic but nondeterministic connectivity. The focus of this dissertation is on routing protocols that send messages in DTNs. When no connected path exists between the source and the destination of the message, other nodes may relay the message to the destination. This dissertation covers routing protocols in DTNs with both deterministic and non-deterministic mobility respectively. In DTNs with deterministic and cyclic mobility, we proposed the first routing protocol that is both scalable and delivery guaranteed. In DTNs with non-deterministic mobility, numerous heuristic protocols are proposed to improve the routing performance. However, none of those can provide a theoretical optimization on a particular performance measurement. In this dissertation, two routing protocols for non-deterministic DTNs are proposed, which minimizes delay and maximizes delivery rate on different scenarios respectively. First, in DTNs with non-deterministic and cyclic mobility, an optimal single-copy forwarding protocol which minimizes delay is proposed., In DTNs with non-deterministic mobility, an optimal multi-copy forwarding protocol is proposed. which maximizes delivery rate under the constraint that the number of copies per message is fixed . Simulation evaluations using both real and synthetic trace are conducted to compare the proposed protocols with the existing ones.
Show less
Date Issued
2009
PURL
http://purl.flvc.org/FAU/210522
Subject Headings
Computer network protocols, Computer networks, Reliability, Computer algorithms, Wireless communication systems, Technological innovations
Format
Document (PDF)
Scheduling for composite event detection in wireless sensor networks
Title
Scheduling for composite event detection in wireless sensor networks.
Creator
Ambrose, Arny Isonja, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
Wireless sensor networks are used in areas that are inaccessible, inhospitable or for continuous monitoring. The main use of such networks is for event detection. Event detection is used to monitor a particular environment for an event such as fire or flooding. Composite event detection is used to break down the detection of the event into the specific conditions that need to be present for the event to occur. Using this method, each sensor node does not need to carry every sensing component...
Show moreWireless sensor networks are used in areas that are inaccessible, inhospitable or for continuous monitoring. The main use of such networks is for event detection. Event detection is used to monitor a particular environment for an event such as fire or flooding. Composite event detection is used to break down the detection of the event into the specific conditions that need to be present for the event to occur. Using this method, each sensor node does not need to carry every sensing component necessary to detect the event. Since energy efficiency is important the sensor nodes need to be scheduled so that they consume [sic] consume as little energy as possible to extend the network lifetime. In this thesis, a solution to the sensor Scheduling for Composite Event Detection (SCED) problem will be presented as a way to improve the network lifetime when using composite event detection.
Show less
Date Issued
2008
PURL
http://purl.flvc.org/fcla/dt/186333
Subject Headings
Sensor networks, Wireless communication systems, Embedded computer systems, Computer systems, Reliability
Format
Document (PDF)