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109
Controlled sink mobility for prolonging wireless sensor networks lifetime
, 2008
"... This paper demonstrates the advantages of using controlled mobility in wireless sensor networks (WSNs) for increasing their lifetime, i.e., the period of time the network is able to provide its intended functionalities. More specifically, for WSNs that comprise a large number of statically placed s ..."
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Cited by 48 (1 self)
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This paper demonstrates the advantages of using controlled mobility in wireless sensor networks (WSNs) for increasing their lifetime, i.e., the period of time the network is able to provide its intended functionalities. More specifically, for WSNs that comprise a large number of statically placed sensor nodes transmitting data to a collection point (the sink), we show that by controlling the sink movements we can obtain remarkable lifetime improvements. In order to determine sink movements, we first define a Mixed Integer Linear Programming (MILP) analytical model whose solution determines those sink routes that maximize network lifetime. Our contribution expands further by defining the first heuristics for controlled sink movements that are fully distributed and localized. Our Greedy Maximum Residual Energy (GMRE) heuristic moves the sink from its current location to a new site as if drawn toward the area where nodes have the highest residual energy. We also introduce a simple distributed mobility scheme (Random Movement or
Sensor Networks with Mobile Access: Optimal Random Access and Coding
- IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS: SPECIAL ISSUE ON SENSOR NETWORKS
, 2004
"... We consider random access and coding schemes for sensor networks with mobile access (SENMA). Using an orthogonal code-division multiple access (CDMA) as the physical layer, an opportunistic ALOHA (O-ALOHA) protocol that utilizes channel state information is proposed. Under the packet capture model ..."
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Cited by 26 (5 self)
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We consider random access and coding schemes for sensor networks with mobile access (SENMA). Using an orthogonal code-division multiple access (CDMA) as the physical layer, an opportunistic ALOHA (O-ALOHA) protocol that utilizes channel state information is proposed. Under the packet capture model and using the asymptotic throughput as the performance metric, we show that O-ALOHA approaches the throughput equal to the spreading gain with an arbitrarily small power at each sensor. This result implies that O-ALOHA is close to the optimal centralized scheduling scheme for the orthogonal CDMA networks. When side information such as location is available, the transmission control is modified to incorporate either the distribution or the actual realization of the side information. Convergence of the throughput with respect to the size of the network is analyzed. For networks allowing sensor collaborations, we combine coding with random access by proposing two coded random access schemes: spreading code dependent and independent transmissions. In the low rate regime, the spreading code independent transmission has a larger random coding exponent (therefore, faster decay of error probability) than that of the spreading code dependent transmission. On the other hand, the spreading code dependent transmission gives higher achievable rate.
Agilla: A Mobile Agent Middleware for Self-Adaptive Wireless Sensor Networks
"... This article presents Agilla, a mobile agent middleware designed to support self-adaptive applications in wireless sensor networks. Agilla provides a programming model in which applications consist of evolving communities of agents that share a wireless sensor network. Coordination among the agents ..."
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Cited by 24 (1 self)
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This article presents Agilla, a mobile agent middleware designed to support self-adaptive applications in wireless sensor networks. Agilla provides a programming model in which applications consist of evolving communities of agents that share a wireless sensor network. Coordination among the agents and access to physical resources are supported by a tuple space abstraction. Agents can dynamically enter and exit a network and can autonomously clone and migrate themselves in response to environmental changes. Agilla’s ability to support self-adaptive applications in wireless sensor networks has been demonstrated in the context of several applications, including fire detection and tracking, monitoring cargo containers, and robot navigation. Agilla, the first mobile agent system to operate in resource-constrained wireless sensor platforms, was implemented on top of TinyOS. Agilla’s feasibility and efficiency was demonstrated by experimental evaluation on two physical testbeds consisting of Mica2 and TelosB nodes.
Sensor Networks with Mobile Access: Energy and Capacity Considerations
- IEEE Trans. Comm
, 2006
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Cooperative Sensor Networks with Misinformed Sensors
, 2004
"... We consider the communication from a cooperative sensor network to a mobile access point. We assume that sensors are informed with a global message and some nodes are misinformed with random messages. Nodes transmit to the mobile access point in a pre-scheduled order. We derive an achievable rate fo ..."
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Cited by 17 (5 self)
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We consider the communication from a cooperative sensor network to a mobile access point. We assume that sensors are informed with a global message and some nodes are misinformed with random messages. Nodes transmit to the mobile access point in a pre-scheduled order. We derive an achievable rate for the information retrieval process when sensors are transmitting at a time. For the Gaussian multiple access channel under the total network power constraint, we show that the maximum achievable rate for the Gaussian multiple access channel is O(log 2 d), obeying the same scaling law as the capacity of an Gaussian multiple-input-single-output channel.
An Integrated Approach to Energy-Aware Medium Access for Wireless Sensor Networks
- IEEE TRANSACTIONS ON SIGNAL PROCESSING
, 2005
"... This report addresses the design of distributed medium access control (MAC) protocols for wireless sensor networks under the performance measure of network lifetime. Integrated in the design of MAC schemes are two key physical layer parameters: the channel state and the residual energy of each senso ..."
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Cited by 17 (2 self)
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This report addresses the design of distributed medium access control (MAC) protocols for wireless sensor networks under the performance measure of network lifetime. Integrated in the design of MAC schemes are two key physical layer parameters: the channel state and the residual energy of each sensor. The impact of incorporating these parameters in MAC design on network lifetime is studied. Furthermore, we show that a lifetime-maximizing protocol should dynamically trade off the channel state information (CSI) and the residual energy information (REI) according to the age of the network. Specifically, lifetime-maximizing protocols should be more opportunistic by prioritizing sensors with better channels for transmission when the network is young and more conservative by favoring sensors with more residual energies when the network is old. Following this general design principle, we propose a dynamic protocol for lifetime maximization (DPLM) that exploits both CSI and REI. Analytical results are provided to demonstrate the dynamic property and the asymptotic optimality of DPLM.
Asymptotic Locally Optimal Detector for Large-Scale Sensor Networks under the Poisson Regime
- IEEE Trans. Signal Processing
, 2003
"... We consider distributed detection with a large number of identical binary sensors deployed over a region where the phenomenon of interest (POI) has spatially varying signal strength. Each sensor makes a decision based on its own measurement, and the local decision of each sensor is sent to a fusion ..."
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Cited by 16 (2 self)
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We consider distributed detection with a large number of identical binary sensors deployed over a region where the phenomenon of interest (POI) has spatially varying signal strength. Each sensor makes a decision based on its own measurement, and the local decision of each sensor is sent to a fusion center using a random access protocol. The fusion center decides whether the POI has occurred under a global size constraint in the Neyman-Pearson formulation. Assuming a homogeneous Poisson distributed sensors, we show that the distribution of `alarmed' sensors satisfies the locally asymptotically normal (LAN) condition. We then derive an asymptotically locally most powerful (ALMP) detector optimized jointly over the fusion form and local sensor threshold. Su#cient conditions on the spatial signal shape for the existence of ALMP detector are established. We show that the ALMP test statistic is a weighted sum of local decisions with the optimal weight function as the shape of the spatial signal, and the exact value of the signal strength is not required. We also derive the optimal threshold for each sensor. For the case of independent, identical distributed (i.i.d.) sensor observation, we show that the counting-based detector is also ALMP under the Poisson regime. The performance of the proposed detector is evaluated through analytic results and Monte-Carlo simulations, and compared with that of the counting-based detector for spatially-varying signals. The e#ect of mismatched signal shapes is also investigated.
Sensor Network with Multiple Mobile Access Points
- in Proc. 2004 CISS
, 2004
"... We consider sensor networks with mobile access points where data at sensor nodes are collected by multiple mobile access points. Using throughput and energy efficiency as performance measures, we address the optimal coverage areas of and the cooperation among the mobile access points. We show that w ..."
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Cited by 15 (5 self)
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We consider sensor networks with mobile access points where data at sensor nodes are collected by multiple mobile access points. Using throughput and energy efficiency as performance measures, we address the optimal coverage areas of and the cooperation among the mobile access points. We show that when the mobile access points do not cooperate in demodulation, disjoint coverage areas are optimal for throughput while completely overlapped coverage areas are optimal for energy efficiency. When the mobile access points decode their received packets jointly, the optimal configuration appears to have a phase transition. Specifically, in order to maximize throughput, the coverage areas of the mobile access points should be completely overlapped when SNR is smaller than a threshold and disjoint otherwise.
Estimation Over deterministic multiaccess channels
- in Proceedings of the 42nd Allerton Conf. on Communications, Control, and Computing
, 2004
"... We study the problem of communicating sensor readings over a Gaussian multiaccess (MAC) channel. We focus on the scenario that each sensor observes a single random variable, and transmits it using certain signaling in a shared channel. The objective is the design of channel waveforms (i.e., signal c ..."
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Cited by 13 (3 self)
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We study the problem of communicating sensor readings over a Gaussian multiaccess (MAC) channel. We focus on the scenario that each sensor observes a single random variable, and transmits it using certain signaling in a shared channel. The objective is the design of channel waveforms (i.e., signal constellation) to facilitate the estimation of field parameters from the channel output. We propose a new approach named Histogram-Delivering Multiple Access (HDMA). In case of symmetric channel gains, it is shown that the HDMA is asymptotically optimal in the limit of large number of sensors. In particular, we show that the HDMA together with a variant of the maximum-likelihood estimator achieves the Cramer-Rao lower bound asymptotically. We then compare the performance of HDMA with other approaches that allocate orthogonal channels to sensors such as TDMA.
