656 research outputs found
Reliable Energy-Efficient Routing Algorithm for Vehicle-Assisted Wireless Ad-Hoc Networks
We investigate the design of the optimal routing path in a moving vehicles
involved the internet of things (IoT). In our model, jammers exist that may
interfere with the information exchange between wireless nodes, leading to
worsened quality of service (QoS) in communications. In addition, the transmit
power of each battery-equipped node is constrained to save energy. We propose a
three-step optimal routing path algorithm for reliable and energy-efficient
communications. Moreover, results show that with the assistance of moving
vehicles, the total energy consumed can be reduced to a large extend. We also
study the impact on the optimal routing path design and energy consumption
which is caused by path loss, maximum transmit power constrain, QoS
requirement, etc.Comment: 6 pages, 5 figures, rejected by IEEE Globecom 2017,resubmit to IEEE
WCNC 201
Katakan tidak pada rasuah
Isu atau masalah rasuah menjadi topik utama sama ada di peringkat antarabangsa mahupun di peringkat dalam negara. Pertubuhan Bangsa- bangsa Bersatu menegaskan komitmen komuniti antarabangsa bertegas untuk mencegah dan mengawal rasuah melalui buku bertajuk United Nations Convention against Corruption. Hal yang sama berlaku di Malaysia. Melalui pernyataan visi oleh mantan Perdana Menteri Malaysia, Tun Dr. Mahathir bin Mohamed memberikan indikasi bahawa kerajaan Malaysia komited untuk mencapai aspirasi agar Malaysia dikenali kerana integriti dan bukannya rasuah. Justeru, tujuan penulisan bab ini adalah untuk membincangkan rasuah dari beberapa sudut termasuk perbincangan dari sudut agama Islam, faktor-faktor berlakunya gejala rasuah, dan usaha-usaha yang dijalankan di Malaysia untuk membanteras gejala rasuah. Perkara ini penting bagi mengenalpasti penjawat awam menanamkan keyakinan dalam melaksanakan tanggungjawab dengan menghindari diri daripada rasuah agar mereka sentiasa peka mengutamakan kepentingan awam
Supporting Cyber-Physical Systems with Wireless Sensor Networks: An Outlook of Software and Services
Sensing, communication, computation and control technologies are the essential building blocks of a cyber-physical system (CPS). Wireless sensor networks (WSNs) are a way to support CPS as they provide fine-grained spatial-temporal sensing, communication and computation at a low premium of cost and power. In this article, we explore the fundamental concepts guiding the design and implementation of WSNs. We report the latest developments in WSN software and services for meeting existing requirements and newer demands; particularly in the areas of: operating system, simulator and emulator, programming abstraction, virtualization, IP-based communication and security, time and location, and network monitoring and management. We also reflect on the ongoing
efforts in providing dependable assurances for WSN-driven CPS. Finally, we report on its applicability with a case-study on smart buildings
Performance Assessment of Routing Protocols for IoT/6LoWPAN Networks
The Internet of Things (IoT) proposes a disruptive communication paradigm that allows
smart objects to exchange data among themselves to reach a common goal. IoT application
scenarios are multiple and can range from a simple smart home lighting system to fully controlled
automated manufacturing chains. In the majority of IoT deployments, things are equipped with
small devices that can suffer from severe hardware and energy restrictions that are responsible
for performing data processing and wireless communication tasks. Thus, due to their features,
communication networks that are used by these devices are generally categorized as Low Power
and Lossy Networks (LLNs).
The considerable variation in IoT applications represents a critical issue to LLN networks,
which should offer support to different requirements as well as keeping reasonable
quality-of-service (QoS) levels. Based on this challenge, routing protocols represent a key issue
in IoT scenarios deployment. Routing protocols are responsible for creating paths among devices
and their interactions. Hence, network performance and features are highly dependent
on protocol behavior. Also, based on the adopted protocol, the support for some specific requirements
of IoT applications may or may not be provided. Thus, a routing protocol should be
projected to attend the needs of the applications considering the limitations of the device that
will execute them.
Looking to attend the demand of routing protocols for LLNs and, consequently, for IoT
networks, the Internet Engineering Task Force (IETF) has designed and standardized the IPv6
Routing Protocol for Low Power and Lossy Networks (RPL). This protocol, although being robust
and offering features to fulfill the need of several applications, still presents several faults and
weaknesses (mainly related to its high complexity and memory requirement), which limits its
adoption in IoT scenarios. An alternative to RPL, the Lightweight On-demand Ad Hoc Distancevector
Routing Protocol â Next Generation (LOADng) has emerged as a less complicated routing
solution for LLNs. However, the cost of its simplicity is paid for with the absence of adequate
support for a critical set of features required for many IoT environments. Thus, based on the
challenging open issues related to routing in IoT networks, this thesis aims to study and propose
contributions to better attend the network requirements of IoT scenarios. A comprehensive survey,
reviewing state-of-the-art routing protocols adopted for IoT, identified the strengths and
weaknesses of current solutions available in the literature. Based on the identified limitations,
a set of improvements is designed to overcome these issues and enhance IoT network performance.
The novel solutions are proposed to include reliable and efficient support to attend
the needs of IoT applications, such as mobility, heterogeneity, and different traffic patterns.
Moreover, mechanisms to improve the network performance in IoT scenarios, which integrate
devices with different communication technologies, are introduced.
The studies conducted to assess the performance of the proposed solutions showed
the high potential of the proposed solutions. When the approaches presented in this thesis
were compared with others available in the literature, they presented very promising results
considering the metrics related to the Quality of Service (QoS), network and energy efficiency,
and memory usage as well as adding new features to the base protocols. Hence, it is believed
that the proposed improvements contribute to the state-of-the-art of routing solutions for IoT
networks, increasing the performance and adoption of enhanced protocols.A Internet das Coisas, do inglĂȘs Internet of Things (IoT), propĂ”e um paradigma de
comunicação disruptivo para possibilitar que dispositivos, que podem ser dotados de comportamentos
autónomos ou inteligentes, troquem dados entre eles buscando alcançar um objetivo
comum. Os cenårios de aplicação do IoT são muito variados e podem abranger desde um simples
sistema de iluminação para casa até o controle total de uma linha de produção industrial. Na
maioria das instalaçÔes IoT, as âcoisasâ sĂŁo equipadas com um pequeno dispositivo, responsĂĄvel
por realizar as tarefas de comunicação e processamento de dados, que pode sofrer com severas
restriçÔes de hardware e energia. Assim, devido Ă s suas caracterĂsticas, a rede de comunicação
criada por esses dispositivos Ă© geralmente categorizada como uma Low Power and Lossy Network
(LLN).
A grande variedade de cenĂĄrios IoT representam uma questĂŁo crucial para as LLNs,
que devem oferecer suporte aos diferentes requisitos das aplicaçÔes, alĂ©m de manter nĂveis
de qualidade de serviço, do inglĂȘs Quality of Service (QoS), adequados. Baseado neste desafio,
os protocolos de encaminhamento constituem um aspecto chave na implementação de
cenĂĄrios IoT. Os protocolos de encaminhamento sĂŁo responsĂĄveis por criar os caminhos entre
os dispositivos e permitir suas interaçÔes. Assim, o desempenho e as caracterĂsticas da rede
sĂŁo altamente dependentes do comportamento destes protocolos. Adicionalmente, com base
no protocolo adotado, o suporte a alguns requisitos especĂficos das aplicaçÔes de IoT podem
ou nĂŁo ser fornecidos. Portanto, estes protocolos devem ser projetados para atender as necessidades
das aplicaçÔes assim como considerando as limitaçÔes do hardware no qual serão
executados.
Procurando atender Ă s necessidades dos protocolos de encaminhamento em LLNs e,
consequentemente, das redes IoT, a Internet Engineering Task Force (IETF) desenvolveu e padronizou
o IPv6 Routing Protocol for Low Power and Lossy Networks (RPL). O protocolo, embora
seja robusto e ofereça recursos para atender às necessidades de diferentes aplicaçÔes, apresenta
algumas falhas e fraquezas (principalmente relacionadas com a sua alta complexidade e
necessidade de memória) que limitam sua adoção em cenårios IoT. Em alternativa ao RPL, o
Lightweight On-demand Ad hoc Distance-vector Routing Protocol â Next Generation (LOADng)
emergiu como uma solução de encaminhamento menos complexa para as LLNs. Contudo, o
preço da simplicidade é pago com a falta de suporte adequado para um conjunto de recursos
essenciais necessårios em muitos ambientes IoT. Assim, inspirado pelas desafiadoras questÔes
ainda em aberto relacionadas com o encaminhamento em redes IoT, esta tese tem como objetivo
estudar e propor contribuiçÔes para melhor atender os requisitos de rede em cenårios IoT.
Uma profunda e abrangente revisĂŁo do estado da arte sobre os protocolos de encaminhamento
adotados em IoT identificou os pontos fortes e limitaçÔes das soluçÔes atuais. Com base nas debilidades
encontradas, um conjunto de soluçÔes de melhoria Ă© proposto para superar carĂȘncias
existentes e melhorar o desempenho das redes IoT. As novas soluçÔes são propostas para incluir
um suporte confiåvel e eficiente capaz atender às necessidades das aplicaçÔes IoT relacionadas
com suporte à mobilidade, heterogeneidade dos dispositivos e diferentes padrÔes de tråfego.
Além disso, são introduzidos mecanismos para melhorar o desempenho da rede em cenårios IoT
que integram dispositivos com diferentes tecnologias de comunicação.
Os vårios estudos realizados para mensurar o desempenho das soluçÔes propostas mostraram
o grande potencial do conjunto de melhorias introduzidas. Quando comparadas com
outras abordagens existentes na literatura, as soluçÔes propostas nesta tese demonstraram um aumento do desempenho consistente para métricas relacionadas a qualidade de serviço, uso de
memĂłria, eficiĂȘncia energĂ©tica e de rede, alĂ©m de adicionar novas funcionalidades aos protocolos
base. Portanto, acredita-se que as melhorias propostas contribuiem para o avanço do estado
da arte em soluçÔes de encaminhamento para redes IoT e aumentar a adoção e utilização dos
protocolos estudados
Cost Efficiency of Anycast-Based Forwarding in Duty-Cycled WSNs with Lossy Channel
Anycasting has been proposed recently as an efficient communication method for asynchronous duty-cycled wireless sensor networks. However, the interdependencies between end-toend communication cost and the anycasting design parameters have not been systematically studied. In this paper, a statistical endtoend cost model is presented to capture the end-to-end latency and energy consumption of anycasting operation under a realistic wireless channel model. By exploring the relationship between the end-to-end cost efficiency and the forwarding decision dependent anycasting design parameters, two anycasting forwarding metrics are proposed for fully distributed forwarding decision. By exploring the relationship among the preamble length, the size of the forwarding set and the achievable end-to-end cost efficiency, a series of preamble length control guidelines are proposed for low and extremely low duty-cycled WSNs. According to our analytical results and simulation validation, the proposed forwarding metrics help reduce the end-toend latency and energy consumption by about 55% for anycasting with moderate preamble length, compared with the existing heuristic forwarding metrics. The proposed preamble length control guidelines help reduce, by more than half, the end-to-end energy and latency costs in low and extremely-low duty-cycled WSNs
Activity-Aware Sensor Networks for Smart Environments
The efficient designs of Wireless Sensor Network protocols and intelligent Machine Learning algorithms, together have led to the advancements of various systems and applications for Smart Environments. By definition, Smart Environments are the typical physical worlds used in human daily life, those are seamlessly embedded with smart tiny devices equipped with sensors, actuators and computational elements. Since human user is a key component in Smart Environments, human motion activity patterns have key importance in building sensor network systems and applications for Smart Environments. Motivated by this, in this thesis my work is focused on human motion activity-aware sensor networks for Smart Environments. The main contributions of this thesis are in two important aspects: (i) Designing event activity context-aware sensor networks for efficient performance optimization as well as resource usage; and (ii) Using binary motion sensing sensor networks\u27 collective data for device-free real-time tracking of multiple users. Firstly, I describe the design of our proposed event activity context-aware sensor network protocols and system design for Smart Environments. The main motivation behind this work is as follows. A sensor network, unlike a traditional communication network, provides high degree of visibility into the environmental physical processes. Therefore its operation is driven by the activities in the environment. In long-term operations, these activities usually show certain patterns which can be learned and effectively utilized to optimize network design. In this thesis I have designed several novel protocols: (i) ActSee for activity-aware radio duty-cycling, (ii) EAR for activity-aware and energy balanced routing, and (iii) ActiSen complete working system with protocol suites for activity-aware sensing/ duty-cycling/ routing. Secondly, I have proposed and designed FindingHuMo (Finding Human Motion), a Machine Learning based real-time user tracking algorithm for Smart Environments using Sensor Networks. This work has been motivated by increasing adoption of sensor network enabled Ubiquitous Computing in key Smart Environment applications, like Smart Healthcare. Our proposed FindingHuMo protocol and system can perform device-free tracking of multiple (unknown and variable number of) users in the hallway environments, just from non-invasive and anonymous binary motion sensor data
Long-Term Stable Communication in Centrally Scheduled Low-Power Wireless Networks
With the emergence of the Internet of Things (IoT), more devices are connected than ever before. Most of these communicate wirelessly, forming Wireless Sensor Networks. In recent years, there has been a shift from personal networks, like Smart Home, to industrial networks. Industrial networks monitor pipelines or handle the communication between robots in factories. These new applications form the Industrial Internet of Things (IIoT). Many industrial applications have high requirements for communication, higher than the requirements of common IoT networks. Communications must stick to hard deadlines to avoid harm, and they must be highly reliable as skipping information is not a viable option when communicating critical information. Moreover, communication has to remain reliable over longer periods of time. As many sensor locations do not offer a power source, the devices have to run on battery and thus have to be power efficient. Current systems offer solutions for some of these requirements. However, they especially lack long-term stable communication that can dynamically adapt to changes in the wireless medium.In this thesis, we study the problem of stable and reliable communication in centrally scheduled low-power wireless networks. This communication ought to be stable when it can dynamically adapt to changes in the wireless medium while keeping latency at a minimum. We design and investigate approaches to solve the problem of low to high degrees of interference in the wireless medium. We propose three solutions to overcome interference: MASTER with Sliding Windows brings dynamic numbers of retransmissions to centrally scheduled low-power wireless networks, OVERTAKE allows to skip nodes affected by interference along the path, and AUTOBAHN combines opportunistic routing and synchronous transmissions with the Time-Slotted Channel Hopping (TSCH) MAC protocol to overcome local wide-band interference with the lowest possible latency. We evaluate our approaches in detail on testbed deployments and provide open-source implementations of the protocols to enable others to build their work upon them
A critical analysis of mobility management related issues of wireless sensor networks in cyber physical systems
Mobility management has been a long-standing issue in mobile wireless sensor networks and especially in the context of cyber physical systems; its implications are immense. This paper presents a critical analysis of the current approaches to mobility management by evaluating them against a set of criteria which are essentially inherent characteristics of such systems on which these approaches are expected to provide acceptable performance. We summarize these characteristics by using a quadruple set of metrics. Additionally, using this set we classify the various approaches to mobility management that are discussed in this paper. Finally, the paper concludes by reviewing the main findings and providing suggestions that will be helpful to guide future research efforts in the area
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