3,571 research outputs found
Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges
With the rapid development of marine activities, there has been an increasing
number of maritime mobile terminals, as well as a growing demand for high-speed
and ultra-reliable maritime communications to keep them connected.
Traditionally, the maritime Internet of Things (IoT) is enabled by maritime
satellites. However, satellites are seriously restricted by their high latency
and relatively low data rate. As an alternative, shore & island-based base
stations (BSs) can be built to extend the coverage of terrestrial networks
using fourth-generation (4G), fifth-generation (5G), and beyond 5G services.
Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs.
Despite of all these approaches, there are still open issues for an efficient
maritime communication network (MCN). For example, due to the complicated
electromagnetic propagation environment, the limited geometrically available BS
sites, and rigorous service demands from mission-critical applications,
conventional communication and networking theories and methods should be
tailored for maritime scenarios. Towards this end, we provide a survey on the
demand for maritime communications, the state-of-the-art MCNs, and key
technologies for enhancing transmission efficiency, extending network coverage,
and provisioning maritime-specific services. Future challenges in developing an
environment-aware, service-driven, and integrated satellite-air-ground MCN to
be smart enough to utilize external auxiliary information, e.g., sea state and
atmosphere conditions, are also discussed
Aeronautical Ad Hoc Networking for the Internet-Above-The-Clouds
The engineering vision of relying on the ``smart sky" for supporting air
traffic and the ``Internet above the clouds" for in-flight entertainment has
become imperative for the future aircraft industry. Aeronautical ad hoc
Networking (AANET) constitutes a compelling concept for providing broadband
communications above clouds by extending the coverage of Air-to-Ground (A2G)
networks to oceanic and remote airspace via autonomous and self-configured
wireless networking amongst commercial passenger airplanes. The AANET concept
may be viewed as a new member of the family of Mobile ad hoc Networks (MANETs)
in action above the clouds. However, AANETs have more dynamic topologies,
larger and more variable geographical network size, stricter security
requirements and more hostile transmission conditions. These specific
characteristics lead to more grave challenges in aircraft mobility modeling,
aeronautical channel modeling and interference mitigation as well as in network
scheduling and routing. This paper provides an overview of AANET solutions by
characterizing the associated scenarios, requirements and challenges.
Explicitly, the research addressing the key techniques of AANETs, such as their
mobility models, network scheduling and routing, security and interference are
reviewed. Furthermore, we also identify the remaining challenges associated
with developing AANETs and present their prospective solutions as well as open
issues. The design framework of AANETs and the key technical issues are
investigated along with some recent research results. Furthermore, a range of
performance metrics optimized in designing AANETs and a number of
representative multi-objective optimization algorithms are outlined
Towards 6G Networks: Use Cases and Technologies
Reliable data connectivity is vital for the ever increasingly intelligent,
automated and ubiquitous digital world. Mobile networks are the data highways
and, in a fully connected, intelligent digital world, will need to connect
everything, from people to vehicles, sensors, data, cloud resources and even
robotic agents. Fifth generation (5G) wireless networks (that are being
currently deployed) offer significant advances beyond LTE, but may be unable to
meet the full connectivity demands of the future digital society. Therefore,
this article discusses technologies that will evolve wireless networks towards
a sixth generation (6G), and that we consider as enablers for several potential
6G use cases. We provide a full-stack, system-level perspective on 6G scenarios
and requirements, and select 6G technologies that can satisfy them either by
improving the 5G design, or by introducing completely new communication
paradigms.Comment: The paper has been accepted for publication at the IEEE
Communications Magazine, 202
Wireless Internet over Heterogeneous Wireless Networks
One of the two keywords for the next generation wireless communications is seamless. Being involved in the essential e-Japan Plan promoted by the Japanese Government, the MIRAI (Multimedia Integrated network by Radio Access Innovation) project is responsible for the research and development on the seamless integration of various wireless access systems for practical use by the year 2005. A heterogeneous network architecture including a common tool, a common platform, and a common access is proposed in this paper. Concretely, software-defined-radio technologies are used to develop a multi-service user terminal to be used for access to different wireless networks. The common platform for various wireless networks is based on a wireless supporting IPv6 network. A basic access network, separated from other wireless access networks, is used as a means for wireless system discovery, signaling and paging. A proof-of-concept experimental demonstration system is available from March 200
MAC Protocols for Terahertz Communication: A Comprehensive Survey
Terahertz communication is emerging as a future technology to support
Terabits per second link with highlighting features as high throughput and
negligible latency. However, the unique features of the Terahertz band such as
high path loss, scattering and reflection pose new challenges and results in
short communication distance. The antenna directionality, in turn, is required
to enhance the communication distance and to overcome the high path loss.
However, these features in combine negate the use of traditional Medium access
protocols. Therefore novel MAC protocol designs are required to fully exploit
their potential benefits including efficient channel access, control message
exchange, link establishment, mobility management, and line-of-sight blockage
mitigation. An in-depth survey of Terahertz MAC protocols is presented in this
paper. The paper highlights the key features of the Terahertz band which should
be considered while designing an efficient Terahertz MAC protocol, and the
decisions which if taken at Terahertz MAC layer can enhance the network
performance. Different Terahertz applications at macro and nano scales are
highlighted with design requirements for their MAC protocols. The MAC protocol
design issues and considerations are highlighted. Further, the existing MAC
protocols are also classified based on network topology, channel access
mechanisms, and link establishment strategies as Transmitter and Receiver
initiated communication. The open challenges and future research directions on
Terahertz MAC protocols are also highlighted.Comment: Submitted to IEEE Communication Surveys and Tutorials Journa
NFV and SDN - Key Technology Enablers for 5G Networks
Communication networks are undergoing their next evolutionary step towards
5G. The 5G networks are envisioned to provide a flexible, scalable, agile and
programmable network platform over which different services with varying
requirements can be deployed and managed within strict performance bounds. In
order to address these challenges a paradigm shift is taking place in the
technologies that drive the networks, and thus their architecture. Innovative
concepts and techniques are being developed to power the next generation mobile
networks. At the heart of this development lie Network Function Virtualization
and Software Defined Networking technologies, which are now recognized as being
two of the key technology enablers for realizing 5G networks, and which have
introduced a major change in the way network services are deployed and
operated. For interested readers that are new to the field of SDN and NFV this
paper provides an overview of both these technologies with reference to the 5G
networks. Most importantly it describes how the two technologies complement
each other and how they are expected to drive the networks of near future.Comment: This is an accepted version and consists of 11 pages, 9 figures and
32 reference
Low Power Wide Area Networks: An Overview
Low Power Wide Area (LPWA) networks are attracting a lot of attention
primarily because of their ability to offer affordable connectivity to the
low-power devices distributed over very large geographical areas. In realizing
the vision of the Internet of Things (IoT), LPWA technologies complement and
sometimes supersede the conventional cellular and short range wireless
technologies in performance for various emerging smart city and
machine-to-machine (M2M) applications. This review paper presents the design
goals and the techniques, which different LPWA technologies exploit to offer
wide-area coverage to low-power devices at the expense of low data rates. We
survey several emerging LPWA technologies and the standardization activities
carried out by different standards development organizations (e.g., IEEE, IETF,
3GPP, ETSI) as well as the industrial consortia built around individual LPWA
technologies (e.g., LORa Alliance,WEIGHTLESS-SIG, and DASH7 Alliance). We
further note that LPWA technologies adopt similar approaches, thus sharing
similar limitations and challenges. This paper expands on these research
challenges and identifies potential directions to address them. While the
proprietary LPWA technologies are already hitting the market with large
nationwide roll-outs, this paper encourages an active engagement of the
research community in solving problems that will shape the connectivity of tens
of billions of devices in the next decade.Comment: \c{opyright} 2017 IEEE. Personal use of this material is permitted.
Permission from IEEE must be obtained for all other uses, in any current or
future media, including reprinting/republishing this material for advertising
or promotional purposes, creating new collective works, for resale or
redistribution to servers or lists, or reuse of any copyrighted component of
this work in other work
Exploring Broadband Enabled Smart eEnvironment: Wireless Sensor (Mesh) Network
This paper explored the emergent importance of the use sensors as complementary or as alternative to environmental sensing and monitoring, industrial monitoring, and surface explorations. Advances in wireless broadband technology have enabled the use Wireless Sensor (Mesh) Network (WSN), a type mobile ad hoc network (MANET), in all facet of human endeavor. As a next-generation wireless communication, which centered on energy savings, communication reliability, and security, WSN has increased our processing, sensing, and communications capabilities. Hence, this paper is an exploration of recent reliance on sensors as result of broadband enabled smart environment for activities, such as environmental and habitat monitory, military surveillance, target tracking, search and rescue, and logistical tracking and supply-chain management
Algorithms for advance bandwidth reservation in media production networks
Media production generally requires many geographically distributed actors (e.g., production houses, broadcasters, advertisers) to exchange huge amounts of raw video and audio data. Traditional distribution techniques, such as dedicated point-to-point optical links, are highly inefficient in terms of installation time and cost. To improve efficiency, shared media production networks that connect all involved actors over a large geographical area, are currently being deployed. The traffic in such networks is often predictable, as the timing and bandwidth requirements of data transfers are generally known hours or even days in advance. As such, the use of advance bandwidth reservation (AR) can greatly increase resource utilization and cost efficiency. In this paper, we propose an Integer Linear Programming formulation of the bandwidth scheduling problem, which takes into account the specific characteristics of media production networks, is presented. Two novel optimization algorithms based on this model are thoroughly evaluated and compared by means of in-depth simulation results
A Survey on Legacy and Emerging Technologies for Public Safety Communications
Effective emergency and natural disaster management depend on the efficient
mission-critical voice and data communication between first responders and
victims. Land Mobile Radio System (LMRS) is a legacy narrowband technology used
for critical voice communications with limited use for data applications.
Recently Long Term Evolution (LTE) emerged as a broadband communication
technology that has a potential to transform the capabilities of public safety
technologies by providing broadband, ubiquitous, and mission-critical voice and
data support. For example, in the United States, FirstNet is building a
nationwide coast-to-coast public safety network based of LTE broadband
technology. This paper presents a comparative survey of legacy and the
LTE-based public safety networks, and discusses the LMRS-LTE convergence as
well as mission-critical push-to-talk over LTE. A simulation study of LMRS and
LTE band class 14 technologies is provided using the NS-3 open source tool. An
experimental study of APCO-25 and LTE band class 14 is also conducted using
software-defined radio, to enhance the understanding of the public safety
systems. Finally, emerging technologies that may have strong potential for use
in public safety networks are reviewed.Comment: Accepted at IEEE Communications Surveys and Tutorial
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