Search results for "sensor network"
showing 10 items of 380 documents
Enabling Retransmissions for Achieving Reliable Multicast Communications in WSNs
2016
To ensure end-to-end reliable multicast or broadcast transmissions in IEEE 802.15.4 based wireless sensor networks WSNs) is a challenging task since no retransmission and acknowledgment mechanisms are defined in such WSNs. In this paper, we propose three retransmission enabled multicast transmission schemes in order to achieve reliable packet transmissions in such networks. Different from the legacy CSMA/CA principle, these schemes allow a sending or forwarding node to retransmit a packet if necessary and enable implicit or/and explicit acknowledgment for multicast services. Simulations are performed in order to assess the performance of these schemes in terms of number of retransmissions, …
Priority-oriented multicast transmission schemes for heterogeneous traffic in WSNs
2016
To ensure quality of service (QoS) for heterogeneous traffic in IEEE 802.15.4 based wireless sensor networks (WSNs) is a challenging task since no traffic prioritization mechanism is defined in such WSNs. In this paper, we propose two priority-oriented multicast transmission schemes to provide QoS for heterogeneous traffic in WSNs. Contrary to the legacy CSMA/CA and FIFO principles, these schemes differentiate self-generated or received traffic and give priority to delay-sensitive traffic with respect to channel access and packet scheduling. Simulations are performed in order to assess the performance of these schemes in terms of end-to-end delay, energy consumption, packet delivery ratio, …
Evaluation and improvement of collective flooding in WSNs with various link correlations
2015
One of the main challenges confronted by wireless sensor networks (WSNs) is to reduce energy consumption of nodes for the purpose of network lifetime extension. In the literature, many backbone based protocols such as connected dominating set (CDS) and broadcast or multicast based protocols are employed in order to improve network performance in terms of metrics like energy consumption, number of transmissions and dissemination delay. In this paper, we evaluate the performance of a recently proposed transmission protocol known as collective flooding (CF), which is based on link correlation, under various link correlation conditions. Through simulations and analyses we demonstrate that altho…
A 3.3 V Output Voltage Optical Plasmonic Solar Energy Harvester
2021
In this paper, for the first time, the design of a solar energy-harvester (EH) based on plasmonic optical nanorectennas and without the step-up converter is presented. The novel optical harvester with a 49497∗14286 nanoarray of about 21,21 mm2 presents an output voltage value of 3.3 V and an output current of 10 mA.
A real-time network architecture for biometric data delivery in Ambient Intelligence
2012
Ambient Intelligent applications involve the deployment of sensors and hardware devices into an intelligent environment surrounding people, meeting users’ requirements and anticipating their needs (Ambi- ent Intelligence-AmI). Biometrics plays a key role in surveillance and security applications. Fingerprint, iris and voice/speech traits can be acquired by contact, contact-less, and at-a-distance sensors embedded in the environment. Biometric traits transmission and delivery is very critical and it needs real-time transmission net- work with guaranteed performance and QoS. Wireless networks become suitable for AmI if they are able to satisfy real-time communication and security system requi…
A Heterogeneous Sensor and Actuator Network Architecture for Ambient Intelligence
2014
One of the most important characteristics of a typical ambient intelligence scenario is the presence of a number of sensors and actuators that capture information about user preferences and activities. Such nodes, i.e., sensors and actuators, are often based on different technologies so that types of networks which are typically different coexist in a real system, for example, in a home or a building. In this chapter we present a heterogeneous sensor and actuator network architecture designed to separate network management issues from higher, intelligent layers. The effectiveness of the solution proposed here was evaluated using an experimental scenario involving the monitoring of an office…
Improving the Performance Metric of Wireless Sensor Networks with Clustering Markov Chain Model and Multilevel Fusion
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/783543 Open access The paper proposes a performance metric evaluation for a distributed detection wireless sensor network with respect to IEEE 802.15.4 standard. A distributed detection scheme is considered with presence of the fusion node and organized sensors into the clustering and non-clustering networks. Sensors are distributed in clusters uniformly and nonuniformly and network has multilevel fusion centers. Fusion centers act as heads of clusters for decision making based on majority-like received signal strength (RSS) with comparis…
A Logical Framework for Augmented Simulations of Wireless Sensor Networks
2006
This paper describes a framework for practical and efficient monitoring of a wireless sensor network. The architecture proposed exploits the dynamic reasoning capabilities of the situation calculus in order to assess the sensor network behavior before actually deploying all the nodes. Designing a wireless sensor network for a specific application typically involves a preliminary phase of simulations that rely on specialized software, whose behavior does not necessarily reproduce what will be experienced by an actual network. On the other hand, delaying the test phase until deployment may not be advisable due to unreasonable costs. This paper suggests the adoption of a hybrid approach that i…
Graph Filtering with Quantization over Random Time-varying Graphs
2019
Distributed graph filters can be implemented over wireless sensor networks by means of cooperation and exchanges among nodes. However, in practice, the performance of such graph filters is deeply affected by the quantization errors that are accumulated when the messages are transmitted. The latter is paramount to overcome the limitations in terms of bandwidth and computation capabilities in sensor nodes. In addition to quantization errors, distributed graph filters are also affected by random packet losses due to interferences and background noise, leading to the degradation of the performance in terms of the filtering accuracy. In this work, we consider the problem of designing graph filte…
Cooperative communication design with distributed code allocation in a clustered network
2011
A major challenge for cooperative communication in distributed networks is to coordinate relay transmissions without introducing too much overhead. Targeting a clustered network, we propose a novel cooperative communication scheme including channel quality based relay selection and distributed space-time code allocation in this paper. Both analysis and simulations are carried out to investigate the performance of the proposed cooperative scheme, in terms of packet delivery rate, throughput and energy efficiency, under different channel conditions and network density.