Search results for " Sensor Networks."
showing 10 items of 157 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, …
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 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…
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…
On the role of symmetry in solving maximum lifetime problem in two-dimensional sensor networks
2016
We analyze a continuous and discrete symmetries of the maximum lifetime problem in two dimensional sensor networks. We show, how a symmetry of the network and invariance of the problem under a given transformation group $G$ can be utilized to simplify its solution. We prove, that for a $G$-invariant maximum lifetime problem there exists a $G$-invariant solution. Constrains which follow from the $G$-invariance allow to reduce the problem and its solution to a subset, an optimal fundamental region of the sensor network. We analyze in detail solutions of the maximum lifetime problem invariant under a group of isometry transformations of a two dimensional Euclidean plane.
Towards a software-defined Network Operating System for the IoT
2015
The heterogeneity characterizing the Internet of Things (IoT) landscape can be addressed by leveraging network operating systems (NOS)s. Current NOS solutions have been developed for traditional infrastructured networks: they do not take the specific features of fundamental IoT components such as wireless sensor and actuator networks into account. Accordingly, in this paper an innovative integrated network operating system for the IoT which is obtained as the evolution of the Open Network Operating System (ONOS) is proposed. This has been appropriately extended to enhance the recently proposed SDN-WISE platform for supporting SDN in wireless sensor networks and let it interact with standard…
Toward Unified Control of Networks of Switches and Sensors Through a Network Operating System
2018
Wireless sensor networks (WSNs) are an integral part of an Internet of Things (IoT) ecosystem. In fact, a typical IoT service deployment considers an integrated network of switches and sensors (as well as actuators). In order to manage this heterogeneous network infrastructure, the use of software defined networking (SDN) technologies is anticipated. However, existing SDN-enabling technologies consider only isolated networks and there has been no concrete solution that treats the whole network in a unified way. In this paper, a network operating system is proposed as a way to address the above issue. Starting from the open network operating system, which currently supports only OpenFlow net…
Exploiting state information to support QoS in Software-Defined WSNs
2016
Software-Defined Networking (SDN) is a promising paradigm initially proposed for the wired networks which has the potential to change the way in which networks are designed and managed. Recently, its use has been extended to wireless infrastructure-less networks such as ad-hoc and wireless sensor networks. In this paper, we take inspiration from our previous work where a scheme that extends the SDN paradigm to WSNs - called SDN-WISE - was proposed. Differently from OpenFlow, SDN-WISE is stateful; accordingly in this paper we investigate how state can be used to support different levels of QoS in WSNs. In fact, state can be used to represent the level of congestion of a node and rules can be…
Decentralized Lightweight Group Key Management for Dynamic Access Control in IoT Environments
2020
Rapid growth of Internet of Things (IoT) devices dealing with sensitive data has led to the emergence of new access control technologies in order to maintain this data safe from unauthorized use. In particular, a dynamic IoT environment, characterized by a high signaling overhead caused by subscribers' mobility, presents a significant concern to ensure secure data distribution to legitimate subscribers. Hence, for such dynamic environments, group key management (GKM) represents the fundamental mechanism for managing the dissemination of keys for access control and secure data distribution. However, existing access control schemes based on GKM and dedicated to IoT are mainly based on ce…