61 research outputs found
A Comprehensive Survey on Networking over TV White Spaces
The 2008 Federal Communication Commission (FCC) ruling in the United States
opened up new opportunities for unlicensed operation in the TV white space
spectrum. Networking protocols over the TV white spaces promise to subdue the
shortcomings of existing short-range multi-hop wireless architectures and
protocols by offering more availability, wider bandwidth, and longer-range
communication. The TV white space protocols are the enabling technologies for
sensing and monitoring, Internet-of-Things (IoT), wireless broadband access,
real-time, smart and connected community, and smart utility applications. In
this paper, we perform a retrospective review of the protocols that have been
built over the last decade and also the new challenges and the directions for
future work. To the best of our knowledge, this is the first comprehensive
survey to present and compare existing networking protocols over the TV white
spaces.Comment: 19 page
Energy-Sustainable IoT Connectivity: Vision, Technological Enablers, Challenges, and Future Directions
Technology solutions must effectively balance economic growth, social equity,
and environmental integrity to achieve a sustainable society. Notably, although
the Internet of Things (IoT) paradigm constitutes a key sustainability enabler,
critical issues such as the increasing maintenance operations, energy
consumption, and manufacturing/disposal of IoT devices have long-term negative
economic, societal, and environmental impacts and must be efficiently
addressed. This calls for self-sustainable IoT ecosystems requiring minimal
external resources and intervention, effectively utilizing renewable energy
sources, and recycling materials whenever possible, thus encompassing energy
sustainability. In this work, we focus on energy-sustainable IoT during the
operation phase, although our discussions sometimes extend to other
sustainability aspects and IoT lifecycle phases. Specifically, we provide a
fresh look at energy-sustainable IoT and identify energy provision, transfer,
and energy efficiency as the three main energy-related processes whose
harmonious coexistence pushes toward realizing self-sustainable IoT systems.
Their main related technologies, recent advances, challenges, and research
directions are also discussed. Moreover, we overview relevant performance
metrics to assess the energy-sustainability potential of a certain technique,
technology, device, or network and list some target values for the next
generation of wireless systems. Overall, this paper offers insights that are
valuable for advancing sustainability goals for present and future generations.Comment: 25 figures, 12 tables, submitted to IEEE Open Journal of the
Communications Societ
Recommended from our members
A software-defined survivability approach for wireless sensor networks in future internet of the things
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThe Internet of the Things (IoT) is evolving rapidly, and its significant impacts
are expected to affect many application domains. Challenges in areas that humans
have been striving to understand, measure, or predict—such as wildlife, healthcare,
or environmental hazards—are likely to be addressed by the time IoT emerges.
The underlying elements of IoT are wireless sensor networks (WSNs),
which consist of a large number of sensor nodes. In the IoT sphere, sensor nodes
represent tangible objects—Things—that monitor changes, collect information,
and eventually send it through the Internet to a recipient party. Inherently, however,
a wireless sensor node relies on limited computational resources with a limited
power source. These undesirable qualities result in a low level of dependability.
This research explores the viability of applying the unfolding network programmability
concepts to overcome survivability obstacles in WSNs and the IoT. In particular,
it examines the viability of software-defined networking (SDN) in network
lifetime maximisation, failure detection, and failure recovery problems in WSNs.
Software-defined networking is a new network programmability concept
that separates the traditionally-tied control and data planes. It offloads the route
computations and management from network devices to a logically centralised
controller. This separation directly leads to better allocation of computational
resources for the network nodes and allows endless orchestration possibilities for
the controller. This thesis proposes an SDN-based solution to increase the survivability
and resilience of WSN environments. Following an approach that conforms
with the centralised nature of SDN environments and considers the limited resources
of the WSN.
A routing algorithm based on A-star was developed for WSNs, then deployed
within an SDN environment to maximise the network lifetime. Apart from finding the path with the lowest energy burden, the algorithm offloads most of
the control traffic from sensor nodes to the controller. This algorithm resulted
in improved resource utilisation among the nodes due to plane decoupling. Additionally,
it increased the lifetime of the network by 22.6% compared to the widely
explored LEACH protocol.
This thesis also investigates different failure detection and recovery practices
in the SDN architecture. The simulation results show that adopting bidirectional
forwarding detection (BFD) with the asynchronous echo mode for WSN
in an SDN environment reduces control traffic for failure detection to between
27% and 48%. The thesis also evaluates the performance of multiple recovery approaches
when adopting the premises of SDN. The simulation results indicate that
path protection, using group tables from the OpenFlow protocol, has a recovery
time up to eight times shorter than the restoration time. The results of the study
reveal that using protection as a failure recovery technique significantly reduces
control traffic overhead
Recommended from our members
An Anthology of Next-Generation WSNs and Transformative IoT Use-Cases
The Internet of Things (IoT) paradigm brought an ever-increasing dependence on low-power devices to collect sensor data and transmit that information to the cloud, placing greater demand on connectivity and lifespan. In response, rapid worldwide innovation demonstrates the trade-offs in processing, communication, and energy consumption with diverse approaches to low-power components, duty-cycle schemes, cost, and many other critical constraints for complex use-cases, such as track-and-trace (T&T). This work explores the central theme of low-power wireless sensor networks (WSNs) in the IoT and Industrial IoT (IIoT). A collection of publications evolves through the theme, from an IoT literature review to enabling densely-scalable WSNs for logistics & asset management (LAM). Next, this research enhances the WSN design by leveraging wake-up radio (WUR) and energy harvesting (EH) to achieve battery-free operation. Lastly, this work presents WSNs to improve visibility and control of airflow/microclimate management in potentially transformative IIoT use-cases, such as data centers and agriculture
Tecnologias IoT para pastoreio e controlo de postura animal
The unwanted and adverse weeds that are constantly growing in vineyards,
force wine producers to repeatedly remove them through the use of mechanical
and chemical methods. These methods include machinery such
as plows and brushcutters, and chemicals as herbicides to remove and
prevent the growth of weeds both in the inter-row and under-vine areas.
Nonetheless, such methods are considered very aggressive for vines, and, in
the second case, harmful for the public health, since chemicals may remain
in the environment and hence contaminate water lines. Moreover, such
processes have to be repeated over the year, making it extremely expensive
and toilsome. Using animals, usually ovines, is an ancient practice used
around the world. Animals, grazing in vineyards, feed from the unwanted
weeds and fertilize the soil, in an inexpensive, ecological and sustainable
way. However, sheep may be dangerous to vines since they tend to feed
on grapes and on the lower branches of the vines, which causes enormous
production losses. To overcome that issue, sheep were traditionally used to
weed vineyards only before the beginning of the growth cycle of grapevines,
thus still requiring the use of mechanical and/or chemical methods during the
remainder of the production cycle.
To mitigate the problems above, a new technological solution was investigated
under the scope of the SheepIT project and developed in the
scope of this thesis. The system monitors sheep during grazing periods on
vineyards and implements a posture control mechanism to instruct them to
feed only from the undesired weeds. This mechanism is based on an IoT
architecture, being designed to be compact and energy efficient, allowing it to
be carried by sheep while attaining an autonomy of weeks.
In this context, the thesis herein sustained states that it is possible to
design an IoT-based system capable of monitoring and conditioning sheep’s
posture, enabling a safe weeding process in vineyards. Moreover, we support
such thesis in three main pillars that match the main contributions of this
work and that are duly explored and validated, namely: the IoT architecture
design and required communications, a posture control mechanism and
the support for a low-cost and low-power localization mechanism. The
system architecture is validated mainly in simulation context while the posture
control mechanism is validated both in simulations and field experiments.
Furthermore, we demonstrate the feasibility of the system and the contribution
of this work towards the first commercial version of the system.O constante crescimento de ervas infestantes obriga os produtores a manter
um processo contĂnuo de remoção das mesmas com recurso a mecanismos
mecânicos e/ou quĂmicos. Entre os mais populares, destacam-se o uso de
arados e roçadores no primeiro grupo, e o uso de herbicidas no segundo
grupo. No entanto, estes mecanismos sĂŁo considerados agressivos para as
videiras, assim como no segundo caso perigosos para a saĂşde pĂşblica, visto
que os quĂmicos podem permanecer no ambiente, contaminando frutos e
linhas de água. Adicionalmente, estes processos são caros e exigem mão de
obra que escasseia nos dias de hoje, agravado pela necessidade destes processos
necessitarem de serem repetidos mais do que uma vez ao longo do
ano. O uso de animais, particularmente ovelhas, para controlar o crescimento
de infestantes é uma prática ancestral usada em todo o mundo. As ovelhas,
enquanto pastam, controlam o crescimento das ervas infestantes, ao mesmo
tempo que fertilizam o solo de forma gratuita, ecológica e sustentável. Não
obstante, este método foi sendo abandonado visto que os animais também
se alimentam da rama, rebentos e frutos da videira, provocando naturais
estragos e prejuĂzos produtivos.
Para mitigar este problema, uma nova solução baseada em tecnologias
de Internet das Coisas é proposta no âmbito do projeto SheepIT, cuja espinha
dorsal foi construĂda no âmbito desta tese. O sistema monitoriza as ovelhas
enquanto estas pastoreiam nas vinhas, e implementam um mecanismo de
controlo de postura que condiciona o seu comportamento de forma a que se
alimentem apenas das ervas infestantes. O sistema foi incorporado numa
infraestrutura de Internet das Coisas com comunicações sem fios de baixo
consumo para recolha de dados e que permite semanas de autonomia,
mantendo os dispositivos com um tamanho adequado aos animais.
Neste contexto, a tese suportada neste trabalho defende que Ă© possĂvel
projetar uma sistema baseado em tecnologias de Internet das Coisas,
capaz de monitorizar e condicionar a postura de ovelhas, permitindo que
estas pastem em vinhas sem comprometer as videiras e as uvas. A tese
Ă© suportada em trĂŞs pilares fundamentais que se refletem nos principais
contributos do trabalho, particularmente: a arquitetura do sistema e respetivo
sistema de comunicações; o mecanismo de controlo de postura; e o suporte
para implementação de um sistema de localização de baixo custo e baixo
consumo energético. A arquitetura é validada em contexto de simulação,
e o mecanismo de controlo de postura em contexto de simulação e de
experiências em campo. É também demonstrado o funcionamento do
sistema e o contributo deste trabalho para a conceção da primeira versão
comercial do sistema.Programa Doutoral em Informátic
- …