Results 11 - 20 of 3,193

Practical Network Coding

by Philip A. Chou, Yunnan Wu, Kamal Jain , 2003
"... We propose a distributed scheme for practical network coding that obviates the need for centralized knowledge of the graph topology, the encoding functions, and the decoding functions, and furthermore obviates the need for information to be communicated synchronously through the network. The resu ..."
Abstract - Cited by 462 (15 self) - Add to MetaCart
We propose a distributed scheme for practical network coding that obviates the need for centralized knowledge of the graph topology, the encoding functions, and the decoding functions, and furthermore obviates the need for information to be communicated synchronously through the network

Timer for Ultra-Low-Power Wireless Sensor Node Synchronization

by Yoonmyung Lee, Bharan Giridhar, Zhiyoong Foo, Dennis Sylvester, David Blaauw
"... Recent work in ultra-low-power sensor platforms has enabled a number of new applications in medical, infrastructure, and environmental monitoring. Due to their limited energy storage volume, these sensors operate with long idle times and ultra-low standby power ranging from 10s of nW down to 100s of ..."
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of pW [1-2]. Since radio transmission is relatively expensive, even at the lowest reported power of 0.2mW [3], wireless communication between sensor nodes must be performed infrequently. Accurate measurement of the time interval between communication events (i.e. the synchronization cycle) is of great

Node Synchronization for Minimizing Delay and Energy Consumption in Low-Power-Listening MAC Protocols

by Christophe J. Merlin, Wendi B. Heinzelman
"... Low-power-listening MAC protocols were designed to reduce idle listening, a major source of energy consumption in energy starved wireless sensor networks. Low-powerlistening is a MAC strategy that allows nodes to sleep for ti s (the “inter-listening ” time) when there is no activity concerning them. ..."
Abstract - Cited by 3 (1 self) - Add to MetaCart
communication between the sender and the receiver after the data packet has been successfully received and acknowledged. This results in significant energy savings because a sending node does not need to send for full ti periods. We propose a new and simple approach to synchronize nodes on a slowly changing

SSCH: Slotted Seeded Channel Hopping for Capacity Improvement in IEEE 802.11 Ad-Hoc Wireless Networks

by Paramvir Bahl, Ranveer Chandra - in IEEE 802.11 Ad-Hoc Wireless Networks,” in ACM Mobicom , 2004
"... Capacity improvement is one of the principal challenges in wireless networking. We present a link-layer protocol called Slotted Seeded Channel Hopping, or SSCH, that increases the capacity of an IEEE 802.11 network by utilizing frequency diversity. SSCH can be implemented in software over an IEEE 80 ..."
Abstract - Cited by 353 (3 self) - Add to MetaCart
802.11-compliant wireless card. Each node using SSCH switches across channels in such a manner that nodes desiring to communicate overlap, while disjoint communications mostly do not overlap, and hence do not interfere with each other. To achieve this, SSCH uses a novel scheme for distributed

Capacity bounds and power allocation for wireless relay channels

by Anders Høst-madsen, Junshan Zhang - IEEE TRANS. INF. THEORY , 2005
"... We consider three-node wireless relay channels in a Rayleigh-fading environment. Assuming transmitter channel state information (CSI), we study upper bounds and lower bounds on the outage capacity and the ergodic capacity. Our studies take into account practical constraints on the transmission/rece ..."
Abstract - Cited by 324 (6 self) - Add to MetaCart
/reception duplexing at the relay node and on the synchronization between the source node and the relay node. We also explore power allocation. Compared to the direct transmission and traditional multihop protocols, our results reveal that optimum relay channel signaling can significantly outperform multihop protocols

A wireless sensor network for structural monitoring

by Ning Xu, Sumit Rangwala, Krishna Kant Chintalapudi, Deepak Ganesan, Alan Broad, Ramesh Govindan, Deborah Estrin - SENSYS ’04: PROCEEDINGS OF THE 2ND INTERNATIONAL , 2004
"... Structural monitoring—the collection and analysis of structural response to ambient or forced excitation–is an important application of networked embedded sensing with significant commercial potential. The first generation of sensor networks for structural monitoring are likely to be data acquisitio ..."
Abstract - Cited by 336 (12 self) - Add to MetaCart
acquisition systems that collect data at a single node for centralized processing. In this paper, we discuss the design and evaluation of a wireless sensor network system (called Wisden) for structural data acquisition. Wisden incorporates two novel mechanisms, reliable data transport using a hybrid of end

CRAMER-RAO LOWER BOUND FOR THE CLOCK OFFSET OF SILENT NODES SYNCHRONIZING THROUGH A GENERAL SENDER-RECEIVER PROTOCOL IN WIRELESS SENSORNETS

by Qasim M. Chaudhari, Erchin Serpedin, Khalid Qaraqe
"... Agreement on a common time reference among the nodes is one of the most critical issues in the successful operation of the Wireless Sensor Networks (WSNs). In a previous paper [1], the Maximum Likelihood Estimator (MLE) for the clock offset of the silent nodes overhearing a two-way timing mes-sage e ..."
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Agreement on a common time reference among the nodes is one of the most critical issues in the successful operation of the Wireless Sensor Networks (WSNs). In a previous paper [1], the Maximum Likelihood Estimator (MLE) for the clock offset of the silent nodes overhearing a two-way timing mes

Z-MAC: a Hybrid MAC for Wireless Sensor Networks

by Ajit Warrier, Jeongki Min, Injong Rhee , 2005
"... Z-MAC is a hybrid MAC protocol for wireless sensor networks. It combines the strengths of TDMA and CSMA while offsetting their weaknesses. Nodes are assigned time slots using a distributed implementation of RAND. Unlike TDMA where a node is allowed to transmit only during its own assigned slots, a n ..."
Abstract - Cited by 296 (7 self) - Add to MetaCart
Z-MAC is a hybrid MAC protocol for wireless sensor networks. It combines the strengths of TDMA and CSMA while offsetting their weaknesses. Nodes are assigned time slots using a distributed implementation of RAND. Unlike TDMA where a node is allowed to transmit only during its own assigned slots, a

Wireless Sensor Networks: A New Regime for Time Synchronization

by Jeremy Elson, Kay Römer - IN PROCEEDINGS OF THE FIRST WORKSHOP ON HOT TOPICS IN NETWORKS (HOTNETS-I , 2002
"... Wireless sensor networks (WSNs) consist of large populations of wirelessly connected nodes, capable of computation, communication, and sensing. Sensor nodes cooperate in order to merge individual sensor readings into a high-level sensing result, such as integrating a time series of position measurem ..."
Abstract - Cited by 198 (9 self) - Add to MetaCart
Wireless sensor networks (WSNs) consist of large populations of wirelessly connected nodes, capable of computation, communication, and sensing. Sensor nodes cooperate in order to merge individual sensor readings into a high-level sensing result, such as integrating a time series of position

Capacity of Multi-Channel Wireless Networks with Random (c, f) Assignment

by Vartika Bhandari, et al. , 2007
"... With the availability of multiple unlicensed spectral bands, and potential cost-based limitations on the capabilities of individual nodes, it is increasingly relevant to study the performance of multichannel wireless networks with channel switching constraints. To this effect, some constraint models ..."
Abstract - Cited by 275 (11 self) - Add to MetaCart
With the availability of multiple unlicensed spectral bands, and potential cost-based limitations on the capabilities of individual nodes, it is increasingly relevant to study the performance of multichannel wireless networks with channel switching constraints. To this effect, some constraint
Results 11 - 20 of 3,193