ProFlex: A Probabilistic and Flexible Data Storage Protocol for Heterogeneous Wireless Sensor Networks

This paper presents ProFlex, a proactive data distribution protocol for heterogeneous wireless sensor networks (HWSNs). ProFlex guarantees robustness in data retrieval by intelligently managing data replication among selected storage nodes in the network. Contrarily to related protocols in the literature, ProFlex considers the resource constraints of sensor nodes and constructs multiple data replication structures, which are managed by more powerful nodes. Additionally, ProFlex takes profit of the higher communication range of such powerful nodes in the network and use the long link to improve data distribution. When compared with Supple -- a related protocol, we show by simulation that Proflex increases the network resilience under failures circumstances, decreases the overhead of transmitted messages, and decreases the number of hops to find a specific data in the network.Cet article porte sur la proposition d'un protocole de données proactif de distribution pour les réseaux de capteurs sans fil hétérogènes (HWSNs). Notre protocole, ProFlex, garantit la robustesse de la récupération des données grâce à sa gestion intelligente de la réplication des données entre les nœuds de stockage sélectionnés dans le réseau. Contrairement à d'autres protocoles dans la littérature, ProFlex considère les contraintes de ressources de capteurs et construit plusieurs structures de réplication des données, qui sont gérés par des nœuds plus puissants. En outre, ProFlex profite de la meilleure communication radio de ces nœuds plus puissants et utilise ces longues portée pour améliorer la distribution des données. Nous avons comparé ProFlex avec le protocole Supple et nous avons montré par simulation que Proflex augmente la résilience du réseau, même dans des circonstances des pertes de messages, diminue la surcharge de messages transmis, et diminue le nombre de sauts nécessaire pour trouver un ensemble de données spécifiques dans le réseau

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

Um protocolo de distribuição de dados para redes de sensores sem fio heterogêneas com sink móvel

National audienc

Um protocolo de distribuição de dados para redes de sensores sem fio heterogêneas com sink móvel

National audienc

Um protocolo de distribuição de dados para redes de sensores sem fio heterogêneas com sink móvel

National audienc

HyDi: A Hybrid Data Dissemination Protocol for Highway Scenarios in Vehicular Ad hoc Networks

International audienceIn this paper we tackle the problem of data dissemination under both well-connected and intermittently connected ve- hicular ad hoc networks. For such a purpose, we propose HyDi, a data dissemination protocol suited for highway sce- narios. HyDi can seamless operate under both well-connected networks by applying broadcast suppression techniques in order to avoid contention at the link layer, and also at intermittently connected networks by applying store-carry-forward techniques, thus delivering messages even when an end-to-end path is non-existent. By means of simulation using the recently de ned IEEE 802.11p standard, we compare HyDi against the only two existing solutions in the literature - DV-CAST and SRD - and we show that HyDi has an overhead as good as DV-CAST, outperforms both protocols when considering the average delay under heavy tra cscenarios, decreases the average number of hops to deliver messages and can deliver data to almost all nodes in a given region of interest

HyDi: A Hybrid Data Dissemination Protocol for Highway Scenarios in Vehicular Ad hoc Networks

International audienceIn this paper we tackle the problem of data dissemination under both well-connected and intermittently connected ve- hicular ad hoc networks. For such a purpose, we propose HyDi, a data dissemination protocol suited for highway sce- narios. HyDi can seamless operate under both well-connected networks by applying broadcast suppression techniques in order to avoid contention at the link layer, and also at intermittently connected networks by applying store-carry-forward techniques, thus delivering messages even when an end-to-end path is non-existent. By means of simulation using the recently de ned IEEE 802.11p standard, we compare HyDi against the only two existing solutions in the literature - DV-CAST and SRD - and we show that HyDi has an overhead as good as DV-CAST, outperforms both protocols when considering the average delay under heavy tra cscenarios, decreases the average number of hops to deliver messages and can deliver data to almost all nodes in a given region of interest

A Distributed Data Storage Protocol for Heterogeneous Wireless Sensor Networks With Mobile Sinks

International audienceThis paper presents ProFlex, a distributed data storage protocol for large-scale heterogeneous wireless sensor networks (HWSNs) with mobile sinks. ProFlex guarantees robustness in data collection by intelligently managing data replication among selected storage nodes in the network. Contrarily to related protocols in the literature, ProFlex onsiders the resource constraints of sensor nodes and constructs multiple data replication structures, which are managed by more powerful nodes. Additionally, ProFlex takes advantage of the higher communication range of such powerful nodes and uses the long-range links to improve data distribution by storage nodes. When compared with related protocols, we show through simulation that Proflex has an acceptable performance under message loss scenarios, decreases the overhead of transmitted messages, and decreases the occurrence of the energy hole problem. Moreover, we propose an improvement that allows the protocol to leverage the inherent data correlation and redundancy of wireless sensor networks in order to decrease even further the protocol's overhead without affecting the quality of the data distribution by storage nodes