10 research outputs found
Ubiquity of Healthcare System
Healthcare systems defines the standards for health facilities to communities. Therefore, it is of equal importance to everyone. In addition, it included in every fields of technology such as Internet of Things (IoT), Body Area Networks (BANs), Big Data, Context Aware Computing as well as Machine Learning. Therefore, researchers have opportunity to contribute towards well-being smart society easily. E-health on other hand is trying to provide remote access and availability of Wireless BANs (WBANs) facilities. Since, the tiny economical sensors are attached to body (either by implant or wearable fashion) to monitor the health parameters and act accordingly. Therefore, WBAN standards need special attention for optimization. In our previous work, we have proposed relaying protocol, while in this work we aim to extend the relaying protocol to WBANs in order to achieve better performance and safeguard the Master Node (MN). In order to make ubiquity, we propose to extend this work to small world network. This document described the initial proposal in this regards
Ubiquity of Healthcare System
Healthcare systems defines the standards for health facilities to communities. Therefore, it is of equal importance to everyone. In addition, it included in every fields of technology such as Internet of Things (IoT), Body Area Networks (BANs), Big Data, Context Aware Computing as well as Machine Learning. Therefore, researchers have opportunity to contribute towards well-being smart society easily. E-health on other hand is trying to provide remote access and availability of Wireless BANs (WBANs) facilities. Since, the tiny economical sensors are attached to body (either by implant or wearable fashion) to monitor the health parameters and act accordingly. Therefore, WBAN standards need special attention for optimization. In our previous work, we have proposed relaying protocol, while in this work we aim to extend the relaying protocol to WBANs in order to achieve better performance and safeguard the Master Node (MN). In order to make ubiquity, we propose to extend this work to small world network. This document described the initial proposal in this regards
Valutazione di schemi di trasmissione basati su SR-ARQ
Questa tesi propone uno studio di alcune tecniche di correzione degli errori, basate sul meccanismo Selective Repeat – Automatic Repeat reQuest (SR-ARQ), per analizzare le prestazioni degli schemi, con particolare riferimento al caso di lunghi tempi di propagazione. Mettiamo a confronto l’SR-ARQ con 2 varianti dello stesso, Double Selective Repeat (2SR-ARQ) e Second Replica Selective Repeat (SR2-ARQ). Facciamo così uno studio approssimato sul ritardo medio di consegna (delivery delay, mdelay) di un pacchetto in particolare, quello centrale rispetto a una finestra di larghezza m slots (spazi).
La valutazione si basa su uno studio analitico originale, nel quale vengono ricavati risultati numerici che vengono discussi e illustrat
Previous hop routing: exploiting opportunism in VANETs
Routing in highly dynamic wireless networks such as Vehicular Ad-hoc Networks
(VANETs) is a challenging task due to frequent topology changes. Sustaining
a transmission path between peers in such network environment is difficult. In
this thesis, Previous Hop Routing (PHR) is poposed; an opportunistic forwarding
protocol exploiting previous hop information and distance to destination to
make the forwarding decision on a packet-by-packet basis. It is intended for use in
highly dynamic network where the life time of a hop-by-hop path between source
and destination nodes is short. Exploiting the broadcast nature of wireless communication
avoids the need to copy packets, and enables redundant paths to be
formed. To save network resources, especially under high network loads, PHR
employs probabilistic forwarding. The forwarding probability is calculated based
on the perceived network load as measured by the arrival rate at the network
interface. We evaluate PHR in an urban VANET environment using NS2 (for
network traffic) and SUMO (for vehicular movement) simulators, with scenarios
configured to re
ect real-world conditions. The simulation scenarios are configured
to use two velocity profiles i.e. Low and high velocity. The results show that the
PHR networks able to achieve best performance as measured by Packet Delivery
Ratio (PDR) and Drop Burst Length (DBL) compared to conventional routing
protocols in high velocity scenarios
Conceção e desempenho de retransmissões sem fios cooperativas
Doutoramento em Engenharia Eletrotécnica/TelecomunicaçõesIn recent years, a new paradigm for communication called cooperative communications has been proposed for which initial information theoretic studies have shown the potential for improvements in capacity over traditional multi-hop wireless networks. Extensive research has been done to mitigate the impact of fading in wireless networks, being mostly focused on Multiple-Input Multiple-Output (MIMO) systems. Recently, cooperative relaying techniques have been investigated to increase the performance of wireless systems by using diversity created by different single antenna devices, aiming to reach the same level of performance of MIMO systems with low cost devices.
Cooperative communication is a promising method to achieve high spectrum efficiency and improve transmission capacity for wireless networks.
Cooperative communications is the general idea of pooling the resources of distributed nodes to improve the overall performance of a wireless network.
In cooperative networks the nodes cooperate to help each other. A cooperative node offering help is acting like a middle man or proxy and can convey messages from source to destination.
Cooperative communication involves exploiting the broadcast nature of the wireless medium to form virtual antenna arrays out of independent singleantenna network nodes for transmission. This research aims at contributing to
the field of cooperative wireless networks. The focus of this research is on the relay-based Medium Access Control (MAC) protocol. Specifically, I provide a framework for cooperative relaying called RelaySpot which comprises on
opportunistic relay selection, cooperative relay scheduling and relay switching.
RelaySpot-based solutions are expected to minimize signaling exchange, remove estimation of channel conditions, and improve the utilization of spatial diversity, minimizing outage and increasing reliability.Nos últimos anos foi proposto um novo paradigma de comunicação, chamado de comunicação cooperativa, para o qual estudos iniciais de teoria da informação demonstraram ter potencial para melhorias na capacidade em
redes sem fios tradicionais multi-hop. Uma extensa pesquisa tem sido realizada para mitigar o impacto da atenuação em redes sem fios, tendo-se debruçado principalmente em sistemas Multiple-Input Multiple-Output
(MIMO). Recentemente têm sido investigadas técnicas de retransmissão cooperativas para aumentar o desempenho de sistemas sem fios, usando a diversidade criada por diferentes antenas individuais com o objetivo de atingir o mesmo nível de desempenho dos sistemas MIMO com dispositivos de baixo custo.
A comunicação cooperativa é um método promissor para atingir uma elevada eficiência na ocupação espectral e melhorar a capacidade de transmissão em redes sem fios.
A comunicação cooperativa tem por ideia base a junção de recursos de nós distribuídos para melhorar o desempenho global de uma rede sem fios. Em redes cooperativas os nós cooperam para ajudarem-se mutuamente. Um nó cooperativo que ofereça ajuda estará agindo como um intermediário ou mediador, podendo transmitir mensagens da origem para o destino.
A comunicação cooperativa explora a natureza da transmissão em difusão das comunicações sem fios para formar antenas múltiplas virtuais com vários nós de rede independentes e com antenas únicas. Esta investigação visou
contribuir para a área científica das redes sem fios cooperativas. O foco da pesquisa foi nos protocolos de controlo de acesso ao meio (MAC) com retransmissão cooperativa. Especificamente, proponho uma arquitetura para
enquadrar a retransmissão cooperativa, chamada RelaySpot (ponto de retransmissão), que explora a seleção oportunista de retransmissores, o escalonamento de retransmissores cooperativos e a comutação entre
retransmissores. As comunicações baseadas na RelaySpot deverão ter uma troca de sinalização reduzida, não usam estimativas das condições do canal e melhoram o aproveitamento da diversidade espacial, minimizando a
interrupção e aumentando a fiabilidade
Design, implementation and evaluation of an efficient opportunistic retransmission protocol
10.1145/1614320.1614329Proceedings of the Annual International Conference on Mobile Computing and Networking, MOBICOM73-8