3,930 research outputs found
CNGI/ChinaFLUX: an IPv6-based Terrestrial Ecosystem Flux Research Network in China
In this manuscript, we introduce the first-step research and development onCNGI/ChinaFLUX, which is supported by CNGI (China Next Generation Internet)Project. From May 2012, we set up an IPv6-based real-time carbon flux observationsystem in ten sites, based on the Chinese Terrestrial Ecosystem Flux ResearchNetwork (ChinaFLUX). The hardware environment construction includes IPv6-baseddata transmission network platform, data acquisition system, data storage andprocessing system. The software environment construction includes IPv6-basedobservation device monitoring system, data storage and management system.Researchers develop a series of research applications in CNGI/ChinaFLUX network
Phase Changes in the Evolution of the IPv4 and IPv6 AS-Level Internet Topologies
In this paper we investigate the evolution of the IPv4 and IPv6 Internet
topologies at the autonomous system (AS) level over a long period of time.We
provide abundant empirical evidence that there is a phase transition in the
growth trend of the two networks. For the IPv4 network, the phase change
occurred in 2001. Before then the network's size grew exponentially, and
thereafter it followed a linear growth. Changes are also observed around the
same time for the maximum node degree, the average node degree and the average
shortest path length. For the IPv6 network, the phase change occurred in late
2006. It is notable that the observed phase transitions in the two networks are
different, for example the size of IPv6 network initially grew linearly and
then shifted to an exponential growth. Our results show that following decades
of rapid expansion up to the beginning of this century, the IPv4 network has
now evolved into a mature, steady stage characterised by a relatively slow
growth with a stable network structure; whereas the IPv6 network, after a slow
startup process, has just taken off to a full speed growth. We also provide
insight into the possible impact of IPv6-over-IPv4 tunneling deployment scheme
on the evolution of the IPv6 network. The Internet topology generators so far
are based on an inexplicit assumption that the evolution of Internet follows
non-changing dynamic mechanisms. This assumption, however, is invalidated by
our results.Our work reveals insights into the Internet evolution and provides
inputs to future AS-Level Internet models.Comment: 12 pages, 21 figures; G. Zhang et al.,Phase changes in the evolution
of the IPv4 and IPv6 AS-Level Internet topologies, Comput. Commun. (2010
Modeling the IPv6 Internet AS-level Topology
To measure the IPv6 internet AS-level topology, a network topology discovery
system, called Dolphin, was developed. By comparing the measurement result of
Dolphin with that of CAIDA's Scamper, it was found that the IPv6 Internet at AS
level, similar to other complex networks, is also scale-free but the exponent
of its degree distribution is 1.2, which is much smaller than that of the IPv4
Internet and most other scale-free networks. In order to explain this feature
of IPv6 Internet we argue that the degree exponent is a measure of uniformity
of the degree distribution. Then, for the purpose on modeling the networks, we
propose a new model based on the two major factors affecting the exponent of
the EBA model. It breaks the lower bound of degree exponent which is 2 for most
models. To verify the validity of this model, both theoretical and experimental
analyses have been carried out. Finally, we demonstrate how this model can be
successfully used to reproduce the topology of the IPv6 Internet.Comment: 15 pages, 5 figure
IETF standardization in the field of the Internet of Things (IoT): a survey
Smart embedded objects will become an important part of what is called the Internet of Things. However, the integration of embedded devices into the Internet introduces several challenges, since many of the existing Internet technologies and protocols were not designed for this class of devices. In the past few years, there have been many efforts to enable the extension of Internet technologies to constrained devices. Initially, this resulted in proprietary protocols and architectures. Later, the integration of constrained devices into the Internet was embraced by IETF, moving towards standardized IP-based protocols. In this paper, we will briefly review the history of integrating constrained devices into the Internet, followed by an extensive overview of IETF standardization work in the 6LoWPAN, ROLL and CoRE working groups. This is complemented with a broad overview of related research results that illustrate how this work can be extended or used to tackle other problems and with a discussion on open issues and challenges. As such the aim of this paper is twofold: apart from giving readers solid insights in IETF standardization work on the Internet of Things, it also aims to encourage readers to further explore the world of Internet-connected objects, pointing to future research opportunities
Recent advances in industrial wireless sensor networks towards efficient management in IoT
With the accelerated development of Internet-of- Things (IoT), wireless sensor networks (WSN) are gaining importance in the continued advancement of information and communication technologies, and have been connected and integrated with Internet in vast industrial applications. However, given the fact that most wireless sensor devices are resource constrained and operate on batteries, the communication overhead and power consumption are therefore important issues for wireless sensor networks design. In order to efficiently manage these wireless sensor devices in a unified manner, the industrial authorities should be able to provide a network infrastructure supporting various WSN applications and services that facilitate the management of sensor-equipped real-world entities. This paper presents an overview of industrial ecosystem, technical architecture, industrial device management standards and our latest research activity in developing a WSN management system. The key approach to enable efficient and reliable management of WSN within such an infrastructure is a cross layer design of lightweight and cloud-based RESTful web service
MIRAI Architecture for Heterogeneous Network
One of the keywords that describe next-generation wireless communications is "seamless." As part of the e-Japan Plan promoted by the Japanese Government, the Multimedia Integrated Network by Radio Access Innovation project has as its goal the development of new technologies to enable seamless integration of various wireless access systems for practical use by 2005. This article describes a heterogeneous network architecture including a common tool, a common platform, and a common access. In particular, software-defined radio technologies are used to develop a multiservice user terminal to access 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
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