We devise and evaluate a fully decentralized, light-weight, dynamic clustering algorithm for target tracking. Instead of assuming the same role all sensors, we envision hierarchical sensor network that is composed 1) static backbone sparsely placed high-capability sensors which assume cluster head (CH) upon triggered by certain signal events 2) moderately to densely populated low-end whose function provide information CHs request. A formed CH becomes active, when acoustic strength detected...

Sensor networks can be considered distributed computing platforms with many severe constraints, including limited CPU speed, memory size, power, and bandwidth. Individual nodes in sensor are typically unreliable the network topology dynamically changes, possibly frequently. also differ because of their tight interaction physical environment via sensors actuators. Because this interaction, we find that very data-centric. Due to all these differences, solutions developed for general ad-hoc...

Due to the slow advancement of battery technology, power management in wireless networks remains be a critical issue. Asynchronous wakeup has merits not requiring global clock synchronization and being resilient network dynamics. This paper presents systematic approach designing implementing asynchronous mechanisms ad hoc networks. The optimal schedule design can formulated as block problem combinatorics. We propose neighbor discovery bookkeeping protocol that operate on derived. Two...

In this paper, we present a minimum spanning tree (MST)-based algorithm, called local (LMST), for topology control in wireless multihop networks. each node builds its LMST independently and only keeps on-tree nodes that are one-hop away as neighbors the final topology. We analytically prove several important properties of LMST: 1) derived under preserves network connectivity; 2) degree any resulting is bounded by 6; 3) can be transformed into one with bidirectional links (without impairing...

With the technical advances in ubiquitous comput- ing and wireless networking, there has been an increasing need to capture context information (such as location) figure it into applications. In this paper, we establish theoreti- cal base develop a localization algorithm for building zero- configuration robust indoor tracking system support location-based network services management. The takes input on-line measurements of received signal strengths (RSSs) between 802.11 APs client its...

The importance of spatial reuse in wireless ad-hoc networks has been long recognized as a key to improving the network capacity. One can increase level by either reducing transmit power or increasing carrier sense threshold (thereby range). On other hand, decreases increases, SINR result smaller received signal increased interference level. Consequently, data rate sustained each transmission may decrease. This leads naturally following questions:(1)How trade-off between and decreased node...

In this paper, we explore the fundamental limits of sensor network lifetime that all algorithms can possibly achieve. Specifically, under assumptions nodes are deployed as a Poisson point process with density λ in square region side length l and each cover unit-area disk, first derive necessary sufficient condition node order to maintain complete k-coverage probability approaching 1. With result, obtain if #955; = log l2 + (k+2)log c(l), c(l) → -∞, +∞, (for maintaining coverage) is upper...

Topology control algorithms usually reduce the number of links in a wireless network, which turn decreases degree connectivity. The resulting network topology is more susceptible to system faults such as node failures and departures. In this paper, we consider k-vertex connectivity network. We first present centralized algorithm, Fault-tolerant Global Spanning Subgraph (FGSSk), preserves FGSSk min-max optimal, i.e., minimizes maximum transmission power used among all that preserve Based on...

Recent studies on mobility modeling have focused characterizing user from real traces of wireless LANs (WLANs)and creating models based such characterization. However, most the work does not study how is correlated in time at different scales. For example, future APs with which a will be associated are predicted without knowledge when association take place and for long. In this paper, we build mathematical model both steady state transient behaviors WLANs. Specifically, mode by semi-Markov...

In this paper, we consider the issue of localization in anisotropic sensor networks. Anisotropic networks are differentiated from isotropic that they possess properties vary according to direction measurement. characteristics result various factors such as geographic shape region (non-convex region), different node densities, irregular radio patterns, and terrain conditions. order characterize features, devise a linear mapping method transforms proximity measurements between nodes into...

In this paper, we consider the problem of how to represent locations Internet hosts in a Cartesian coordinate system facilitate estimate network distance between two arbitrary hosts. We envision an infrastructure that consists beacon nodes and provides service estimating without direct delay measurement. show principal component analysis (PCA) technique can effectively extract topological information from measurements Based on PCA, devise transformation method projects data space into new...

In this paper, we develop a model-based frame scheduling scheme, called MFS, to enhance the capacity of IEEE 802.11-operated wireless LANs (WLANs). MFS each node estimates current network status by keeping track number collisions it encounters between its two consecutive successful transmissions, and, based on estimated information, computes utilization. The result is then used determine delay that introduced (with objective avoiding collision) before attempts for transmission pending frame....

Advances in networking, sensors, and embedded devices have made it feasible to monitor provide medical other assistance people their homes. Aging populations will benefit from reduced costs improved healthcare through assisted living based on these technologies. However, systems challenge current state-of-the-art techniques for usability, reliability, security. This is a particular open extensible that combine software hardware many vendors information diverse clinicians. In this paper we...

Identification of a low-level point radiation source amidst background is achieved by network sensors using two-step approach. Based on measurements from three sensors, the geometric difference triangulation method used to estimate location and strength source. Then sequential probability ratio test based current estimated parameters employed finally decide: (1) presence with parameters, or (2) absence source, (3) insufficiency make decision. This achieves specified levels false alarm missed...

Before a sensor network is deployed, it important to determine how many sensors are required achieve certain coverage degree. The number of for maintaining k-coverage depends on the area monitored region, probability that node fails or powers off (to save energy), and deployment strategy. In this paper, we derive density maintain under three strategies: (i) nodes deployed as Poisson point process, (ii) uniformly randomly distributed, (iii) regular grids. Our results show most circumstances,...

In this paper, we extend both Bianchi's and Kumar's models characterize the channel activities governed by IEEE 802.11 DCF in multi-hop wireless networks from perspective of an individual sender. particular, incorporate effect PHY/MAC attributes (such as transmit power physical carrier sense) that need not be considered WLANs but become extraordinarily important networks, derive throughput attained each With use analytical model derived, investigate impact sense threshold on network...

In this paper we study the issue of topology control under physical signal-to-interference-noise-ratio (SINR) model, with objective maximizing network capacity. We show that existing graph-model-based captures interference inadequately SINR and as a result, in thus induced is high capacity attained low. Towards bridging gap, propose centralized approach, called spatial reuse maximizer (MaxSR), combines power algorithm T2P P2T. optimizes assignment transmit given fixed topology, where by...

Broadcast has been widely used in mobile ad hoc networks (MANETs) as a communication means to disseminate information all reachable nodes. However, the conventional broadcast scheme that packets omnidirectionally suffers from several drawbacks: excessive amount of redundant traffic, exaggerated interference/contention between neighboring nodes, and limited coverage (as result contention/collision). This is termed storm problem S.Y.Ni et al. [1999]. In this paper, we address MANETs with use...

In CSMA/CA-based, multi-hop, multi-rate wireless networks, spatial reuse can be increased by tuning the carrier-sensing threshold (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">cs</sub> ) to reduce carrier sense range (d ). While reducing d enables more concurrent transmissions, transmission quality suffers from accumulative interference contributed transmissions outside . As a result, data rate at which sustain may decrease. How balance...

In this article, we explore the fundamental limits of sensor network lifetime that all algorithms can possibly achieve. Specifically, under assumptions nodes are deployed as a Poisson point process with density λ in square region side length ℓ and each cover unit-area disk, first derive necessary sufficient condition node order to maintain complete k -coverage probability approaching 1. With result, obtain if = log 2 + ( 2)loglog c (ℓ), (ℓ) → −∞, ∞, (for maintaining coverage) is upper...