699 research outputs found
Ethernet - a survey on its fields of application
During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal
X-Type Interface for Management of Multidomain Multitechnology Networks
The specification and implementation of Xcoop interfaces has received great attention in the last few years. In fact, the appropriate design of this system component is a key aspect for efficient and seamless co-operative management. In this context it is worth mentioning the EURESCOM P408 project and the standards of the European Telecommunication Standards Institute (ETSI) in Europe and the ITU-T and Telemanagement Forum related work worldwide. The Xcoop specification presented in this paper, produced as part of the results of the project MISA co-funded by the Commission of the European Union, is a step ahead in the evolution of this system interface. Distinguished from preceding works, this one allows interactions between management systems independently to the underlying network technology, ATM, SDH or hybrid. This is achieved by defining appropriate functionality and an information model, indeed, where the specific characteristics of ATM and SDH resources are abstracted and merged in common classes.Peer ReviewedPostprint (published version
Multiplexer Technology in Utility Automation
In utility automation systems, data communication links have the essential role to convey real-time system between control centers and substations. Therefore, reliable and flexible communications are vital to run modern utility network in a safe and properly controlled way.
In this thesis, possibilities of multiplexer technology in communications for utility automation systems are reviewed. At the beginning of this thesis, theory about multiplexing, especially SDH data transmission technology, and essential utility automation systems are discussed. Thereafter, the thesis concentrates on the characteristics and potential applications of the employer’s multiplexer device. Eventually, the performance requirements for the device are analyzed from the utility automation systems’ perspective and also some performance figures are measured with a build-up test system.
Multiplexer technology was found to be well suitable for the underlying communications in utility automation systems. Especially the efficient protection schemes and network manageability makes SDH systems highly available and ensures quick reconfiguration in fault situations. Teleprotection that makes very fast operating times for power line protection possible, came up as the most important application.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format
Cost-effective Information and Communication Technology (ICT) infrastructure for Tanziania
The research conducted an Information and Communication Technology (ICT) field
survey, the results revealed that Tanzania is still lagging behind in the ICT sector due to
the lack of an internationally connected terrestrial ICT infrastructure; Internet connectivity
to the rest of the world is via expensive satellite links, thus leaving the majority of the
population unable to access the Internet services due to its high cost. Therefore, an ICT
backbone infrastructure is designed that exploits optical DWDM network technology,
which un-locks bandwidth bottlenecks and provides higher capacity which will provide
ICT services such as Internet, voice, videos and other multimedia interactions at an
affordable cost to the majority of the people who live in the urban and rural areas of
Tanzania. The research analyses and compares the performance, and system impairments, in a DWDM system at data transmission rates of 2.5 Gb/s and 10 Gb/s per wavelength channel. The simulation results show that a data transmission rate of 2.5 Gb/s can be successfully transmitted over a greater distance than 10 Gb/s with minimum system impairments. Also operating at the lower data rate delivers a good system performance for the required ICT services. A forty-channel DWDM system will provide a bandwidth of 100 Gb/s.
A cost analysis demonstrates the economic worth of incorporating existing optical fibre
installations into an optical DWDM network for the creation of an affordable ICT
backbone infrastructure; this approach is compared with building a completely new optical
fibre DWDM network or a SONET/SDH network. The results show that the ICT backbone
infrastructure built with existing SSMF DWDM network technology is a good investment,
in terms of profitability, even if the Internet charges are reduced to half current rates. The
case for building a completely new optical fibre DWDM network or a SONET/SDH
network is difficult to justify using current financial data
Energy-efficient traffic engineering
The energy consumption in telecommunication networks is expected to grow considerably, especially in core networks. In this chapter, optimization of energy consumption is approached from two directions. In a first study, multilayer traffic engineering (MLTE) is used to assign energy-efficient paths and logical topology to IP traffic. The relation with traditional capacity optimization is explained, and the MLTE strategy is applied for daily traffic variations. A second study considers the core network below the IP layer, giving a detailed power consumption model. Optical bypass is evaluated as a technique to achieve considerable power savings over per-hop opticalelectronicoptical regeneration.
Document type: Part of book or chapter of boo
Planning a Ring-Tree Network to provide Telecommunication Services at Centres of Rural Population
Nowadays
certain
centres
of rural
population
are experimenting
difficulties
to access
high-speed
telecommunication
networks.
This
phenomenon
avoids
the possibility
of accessing
to the digital
revolution
for
such
areas.
The private
companies
are focusing
their invest
ment
efforts
in other
more
profitable
areas.
In such
conditions,
the governments
have
to promote
alternatives
to bridge
the digital
divide
between
rural
and urban
areas.
We present
how
ring-tree
topologies
can be used
as an adequate
architecture
to incorporate
such
less
favoured
areas
in the Information
Society.
We present
a
case study
for Andalucia
(a wide
region
in the south
of
Spain)
where
a decision
support
system
based
on a genetic
algorithm
is implemented
providing
cost effective
solutions.
We make
use of real life data from
the telecommunication
industry
and present
different
solutions
separated
by coverage
as well as a sensitivity
analysis
based
on the main
factors
of the cost function.Ministerio de Ciencia y Tecnología TIC2003 -04784-C02-0
Measurement Based Reconfigurations in Optical Ring Metro Networks
Single-hop wavelength division multiplexing (WDM) optical ring networks operating in packet mode are one of themost promising architectures for the design of innovative metropolitan network (metro) architectures. They permit a cost-effective design, with a good combination of optical and electronic technologies, while supporting features like restoration and reconfiguration that are essential in any metro scenario. In this article, we address the tunability requirements that lead to an effective resource usage and permit reconfiguration in optical WDM metros.We introduce reconfiguration algorithms that, on the basis of traffic measurements, adapt the network configuration to traffic demands to optimize performance. Using a specific network architecture as a reference case, the paper aims at the broader goal of showing which are the advantages fostered by innovative network designs exploiting the features of optical technologies
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