8,787 research outputs found
On Barrier Coverage in Wireless Camera Sensor Networks
[[abstract]]The paper proposed a distributed algorithm, namely CoBRA (Cone-based Barrier coveRage Algorithm), to achieve barrier coverage in wireless camera sensor networks (WCSNs). To the best understanding, CoBRA is the first algorithm which try to deal with the barrier coverage issue in WCSNs. Based on some observations, the basic concept of CoBRA is that each camera sensor can determine the local possible barrier lines according to the geographical relations with their neighbors. A sink in a WCSN initiates Barrier Request (BREQ) messages to form the possible barrier lines. Afterward, a barrier line is constructed by the Barrier Reply (BREQ) message initiated by another sink. CoBRA mainly includes three phases: Initial Phase, Candidate Selection Phase, and Decision Phase. In the Initial Phase, each camera sensor collects the local information of its neighbors and estimates the possible barrier lines. In the Candidate Selection Phase, a sink initiates the BREQ packets and forwards the BREQ packets to camera sensors. Camera sensors receiving the BREQ then reforward the BREQ packets to its neighbors who are capable of forming a barrier line. All camera sensors receiving the BREQ will forward the BREQ to their neighbors again in the same manner. Finally, in the decision phase, after the BREQ message is transmitted through the whole monitoring area, a BREP message is used by the sink to select a barrier line in a WCSN. The barrier coverage is achieved by finding the barrier line in the monitoring area. Experiment results show that CoBRA can efficiently achieve barrier coverage in WCSNs. Comparing to the ideal results, CoBRA can use fewer nodes to accomplish barrier coverage in random deployment scenarios.[[conferencetype]]國際[[conferencedate]]20100420~20100423[[iscallforpapers]]Y[[conferencelocation]]Perth, WA, Australi
Coverage Protocols for Wireless Sensor Networks: Review and Future Directions
The coverage problem in wireless sensor networks (WSNs) can be generally
defined as a measure of how effectively a network field is monitored by its
sensor nodes. This problem has attracted a lot of interest over the years and
as a result, many coverage protocols were proposed. In this survey, we first
propose a taxonomy for classifying coverage protocols in WSNs. Then, we
classify the coverage protocols into three categories (i.e. coverage aware
deployment protocols, sleep scheduling protocols for flat networks, and
cluster-based sleep scheduling protocols) based on the network stage where the
coverage is optimized. For each category, relevant protocols are thoroughly
reviewed and classified based on the adopted coverage techniques. Finally, we
discuss open issues (and recommend future directions to resolve them)
associated with the design of realistic coverage protocols. Issues such as
realistic sensing models, realistic energy consumption models, realistic
connectivity models and sensor localization are covered
Movement-efficient Sensor Deployment in Wireless Sensor Networks
We study a mobile wireless sensor network (MWSN) consisting of multiple
mobile sensors or robots. Two key issues in MWSNs - energy consumption, which
is dominated by sensor movement, and sensing coverage - have attracted plenty
of attention, but the interaction of these issues is not well studied. To take
both sensing coverage and movement energy consumption into consideration, we
model the sensor deployment problem as a constrained source coding problem. %,
which can be applied to different coverage tasks, such as area coverage, target
coverage, and barrier coverage. Our goal is to find an optimal sensor
deployment to maximize the sensing coverage with specific energy constraints.
We derive necessary conditions to the optimal sensor deployment with (i) total
energy constraint and (ii) network lifetime constraint. Using these necessary
conditions, we design Lloyd-like algorithms to provide a trade-off between
sensing coverage and energy consumption. Simulation results show that our
algorithms outperform the existing relocation algorithms.Comment: 18 pages, 10 figure
On the vulnerabilities of voronoi-based approaches to mobile sensor deployment
Mobile sensor networks are the most promising solution to cover an Area of Interest (AoI) in safety critical scenarios. Mobile devices can coordinate with each other according to a distributed deployment algorithm, without resorting to human supervision for device positioning and network configuration. In this paper, we focus on the vulnerabilities of the deployment algorithms based on Voronoi diagrams to coordinate mobile sensors and guide their movements. We give a geometric characterization of possible attack configurations, proving that a simple attack consisting of a barrier of few compromised sensors can severely reduce network coverage. On the basis of the above characterization, we propose two new secure deployment algorithms, named SecureVor and Secure Swap Deployment (SSD). These algorithms allow a sensor to detect compromised nodes by analyzing their movements, under different and complementary operative settings. We show that the proposed algorithms are effective in defeating a barrier attack, and both have guaranteed termination. We perform extensive simulations to study the performance of the two algorithms and compare them with the original approach. Results show that SecureVor and SSD have better robustness and flexibility and excellent coverage capabilities and deployment time, even in the presence of an attac
Safe, Remote-Access Swarm Robotics Research on the Robotarium
This paper describes the development of the Robotarium -- a remotely
accessible, multi-robot research facility. The impetus behind the Robotarium is
that multi-robot testbeds constitute an integral and essential part of the
multi-agent research cycle, yet they are expensive, complex, and time-consuming
to develop, operate, and maintain. These resource constraints, in turn, limit
access for large groups of researchers and students, which is what the
Robotarium is remedying by providing users with remote access to a
state-of-the-art multi-robot test facility. This paper details the design and
operation of the Robotarium as well as connects these to the particular
considerations one must take when making complex hardware remotely accessible.
In particular, safety must be built in already at the design phase without
overly constraining which coordinated control programs the users can upload and
execute, which calls for minimally invasive safety routines with provable
performance guarantees.Comment: 13 pages, 7 figures, 3 code samples, 72 reference
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