1,481 research outputs found
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
On the design of smart parking networks in the smart cities: an optimal sensor placement model
Smart parking is a typical IoT application that can benefit from advances in
sensor, actuator and RFID technologies to provide many services to its users and parking
owners of a smart city. This paper considers a smart parking infrastructure where sensors
are laid down on the parking spots to detect car presence and RFID readers are embedded
into parking gates to identify cars and help in the billing of the smart parking. Both types
of devices are endowed with wired and wireless communication capabilities for reporting
to a gateway where the situation recognition is performed. The sensor devices are tasked
to play one of the three roles: (1) slave sensor nodes located on the parking spot to detect
car presence/absence; (2) master nodes located at one of the edges of a parking lot to detect
presence and collect the sensor readings from the slave nodes; and (3) repeater sensor nodes,
also called ''anchor'' nodes, located strategically at specific locations in the parking lot to
increase the coverage and connectivity of the wireless sensor network. While slave and
master nodes are placed based on geographic constraints, the optimal placement of the
relay/anchor sensor nodes in smart parking is an important parameter upon which the cost
and e ciency of the parking system depends. We formulate the optimal placement of sensors
in smart parking as an integer linear programming multi-objective problem optimizing the
sensor network engineering e ciency in terms of coverage and lifetime maximization, as
well as its economic gain in terms of the number of sensors deployed for a specific coverage
and lifetime. We propose an exact solution to the node placement problem using single-step
and two-step solutions implemented in the Mosel language based on the Xpress-MPsuite of
libraries. Experimental results reveal the relative e ciency of the single-step compared to
the two-step model on di erent performance parameters. These results are consolidated by
simulation results, which reveal that our solution outperforms a random placement in terms
of both energy consumption, delay and throughput achieved by a smart parking network
PERFORMANCE & SIMULATION ANALYSIS OF SENSOR AREA COVERAGE
Wireless sensor networks (WSNs) have been employed in numerous military and civilian applications. Some application areas are in battlefield, surveillance, biological detection, and environmental monitoring. A major challenge to such applications is the sensor areacoverage (SAC), which refers to the techniques and mechanisms of placing sensors and their coordination in a mission space (field) to monitor the physical environment in such a way to achieve the application coverage objectives. This thesis develops a sensor area coverage package (SACPac) that simulates some selected coverage algorithms and their enhancements, and analyzes their performance parameters under various scenarios. The performance parameters considered include coverage ratio, resiliency of the field coverage against sensor failures, energy efficiency, and security of communication among sensors. The thesis also develops a prototype of communication for sending the position of an object via a mobile device to the server on which SACPac runs, so that the object trajectory can be displayed. SACPac provides the foundation for further enhancements and future research. It can also be used as an educational tool for those interested in the SAC problem
Strategies for coverage and focus on event for robotic swarms with limited sensing capabilities
We consider the problem of coverage in Robotic Networks: developing an efficient algorithm which is able to perform a deployment in static-obstacle-structured environments focusing on events is our main idea. We are interested on the trade-off between local communication and optimal coverage, therefore we are going to present an algorithm based on article: "Sensor Coverage Robot Swarms Using Local Sensing without Metric Information", using its similar scenario types
Effiziente Lokalisierung von Nutzern und Geräten in Smarten Umgebungen
The thesis considers determination of location of sensors and users in smart environments using measurements of Received Signal Strength (RSS). The first part of the thesis focuses on localization in Wireless Sensor Networks and contributes two fully distributed algorithms which address the Sensor Selection Problem and provide the best trade-off between energy consumption and localization accuracy among the algorithms considered. Furthermore, the thesis contributes to Device Free Localization an indoor localization concept providing scalable and highly accurate location estimates (prototype: 0.36m² MSE) while using a COTS passive RFID-System and not relying on user-carried sensors
- …