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IEEE 802.15.4 is a new standard to address the need for low-rate low-power low-cost wireless networking. We provide in this paper one of the first simulation-based performance evaluations of the new medium access protocol in IEEE 802.15.4, focusing on its beacon-enabled mode for a star-topology network. We describe its key features such as the superframe(More)
Summary form only given. In many sensor network applications the major traffic pattern consists of data collected from several source nodes to a sink through a unidirectional tree. We propose DMAC, an energy efficient and low latency MAC that is designed and optimized for such data gathering trees in wireless sensor networks. We first show that previously(More)
— The wireless sensor networks community, has now an increased understanding of the need for realistic link layer models. Recent experimental studies have shown that real deployments have a " transitional region " with highly unreliable links, and that therefore the idealized perfect-reception-within-range models used in common network simulation tools can(More)
Sensor networks are distributed event-based systems that differ from traditional communication networks in several ways: sensor networks have severe energy constraints, redundant low-rate data, and many-to-one flows. Data-centric mechanisms that perform in-network aggregation of data are needed in this setting for energy-efficient information flow. In this(More)
—We propose a distributed solution for a canonical task in wireless sensor networks—the binary detection of interesting environmental events. We explicitly take into account the possibility of sensor measurement faults and develop a distributed Bayesian algorithm for detecting and correcting such faults. Theoretical analysis and simulation results show that(More)
Urban sensing, participatory sensing, and user activity recognition can provide rich contextual information for mobile applications such as social networking and location-based services. However, continuously capturing this contextual information on mobile devices consumes huge amount of energy. In this paper, we present a novel design framework for an(More)
We find that the IEEE 802.15.4 MAC protocol performs poorly for one-hop data collection in dense sensor networks, showing a steep deterioration in both throughput and energy consumption with increasing number of transmitters. We propose a channel feedback-based enhancement to the protocol that is significantly more scalable, showing a relatively flat,(More)
This paper considers opportunistic communication over multiple channels where the state (ldquogoodrdquo or ldquobadrdquo) of each channel evolves as independent and identically distributed (i.i.d.) Markov processes. A user, with limited channel sensing capability, chooses one channel to sense and decides whether to use the channel (based on the sensing(More)
Energy-efficiency, one of the major design goals in wireless cellular networks, has received much attention lately, due to increased awareness of environmental issues and economic issues for network operators. In this paper, we develop a theoretical framework for BS energy saving that encompasses dynamic BS operation and the related problem of user(More)
We formulate the following combinatorial multiarmed bandit (MAB) problem: There are <i>N</i> random variables with unknown mean that are each instantiated in an i.i.d. fashion over time. At each time multiple random variables can be selected, subject to an arbitrary constraint on weights associated with the selected variables. All of the selected individual(More)