1,077 research outputs found
Multi-threaded Simulation of 4G Cellular Systems within the LTE-Sim Framework
Nowadays, an always increasing number of researchers and industries are putting a large effort in the design and the implementation of protocols, algorithms, and network architectures targeted at the the emerging 4G cellular technology. In this context, multi-core/multi-processor simulation tools can accelerate their activities by drastically reducing the time required to simulate complex scenarios. Unfortunately, today's available tools are mostly single-threaded and they cannot exploit the performance gain offered by parallel programming approaches. To bridge this gap, we have significantly upgraded the LTE-Sim framework by implementing a concurrent scheduling algorithm, namely the Multi-Master Scheduler, aimed at efficiently handling events in a parallel manner, while guaranteeing the correct execution of the simulation itself. Experimental results will demonstrate the effectiveness of our proposal and the performance gain that can be achieved with respect to other classical event scheduling algorithms
Will SDN be part of 5G?
For many, this is no longer a valid question and the case is considered
settled with SDN/NFV (Software Defined Networking/Network Function
Virtualization) providing the inevitable innovation enablers solving many
outstanding management issues regarding 5G. However, given the monumental task
of softwarization of radio access network (RAN) while 5G is just around the
corner and some companies have started unveiling their 5G equipment already,
the concern is very realistic that we may only see some point solutions
involving SDN technology instead of a fully SDN-enabled RAN. This survey paper
identifies all important obstacles in the way and looks at the state of the art
of the relevant solutions. This survey is different from the previous surveys
on SDN-based RAN as it focuses on the salient problems and discusses solutions
proposed within and outside SDN literature. Our main focus is on fronthaul,
backward compatibility, supposedly disruptive nature of SDN deployment,
business cases and monetization of SDN related upgrades, latency of general
purpose processors (GPP), and additional security vulnerabilities,
softwarization brings along to the RAN. We have also provided a summary of the
architectural developments in SDN-based RAN landscape as not all work can be
covered under the focused issues. This paper provides a comprehensive survey on
the state of the art of SDN-based RAN and clearly points out the gaps in the
technology.Comment: 33 pages, 10 figure
A cooperative cellular and broadcast conditional access system for Pay-TV systems
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2009 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, 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 components of this work in other works.The lack of interoperability between Pay-TV service providers and a horizontally integrated business transaction model have compromised the competition in the Pay-TV market. In addition, the lack of interactivity with customers has resulted in high churn rate and improper security measures have contributed into considerable business loss. These issues are the main cause of high operational costs and subscription fees in the Pay-TV systems. As a result, this paper presents the Mobile Conditional Access System (MICAS) as an end-to-end access control solution for Pay-TV systems. It incorporates the mobile and broadcasting systems and provides a platform whereby service providers can effectively interact with their customers, personalize their services and adopt appropriate security measurements. This would result in the decrease of operating expenses and increase of customers' satisfaction in the system. The paper provides an overview of state-of-the-art conditional access solutions followed by detailed description of design, reference model implementation and analysis of possible MICAS security architectures.Strategy & Technology (S&T) Lt
Software defined wireless network (sdwn) for industrial environment: case of underground mine
Avec le développement continu des industries minières canadiennes, l’établissement des réseaux de communications souterrains avancés et sans fil est devenu un élément essentiel du processus industriel minier et ceci pour améliorer la productivité et assurer la communication entre les mineurs. Cette étude vise à proposer un système de communication minier en procurant une architecture SDWN (Software Defined Wireless Network) basée sur la technologie de communication LTE. Dans cette étude, les plateformes les plus importantes de réseau mobile 4G ont été étudiées, configurées et testées dans deux zones différentes : un tunnel de mine souterrain et un couloir intérieur étroit. Également, une architecture mobile combinant SDWN et NFV (Network Functions Virtualization) a été réalisée
A CASE STUDY OF VARIOUS WIRELESS NETWORK SIMULATION TOOLS
4G is the fastest developing system in the history of mobile communication networks. Network connectivity is paramount for all kinds of big enterprises. Â 4G not only provides super-fast connectivity to millions of users, but can also act as an enterprise network connectivity enabler and it has inherent advantages such as higher bandwidth, low latency, higher spectrum efficiency along with backward compatibility and future proofing. The design of the 4G based Long Term Evolution physical network provides the required flexibility for optimization during the development phase. In this paper LTE Network related supporting simulation tools is presented to demonstrate the need of Hardware co-simulation of the LTE system. After the feasibility analysis, the importance of the model is to be ported Field Programmable Gate Array platform is examined in survey in detail with the supporting inferences along with the comparison of different wireless network simulators suitable for LTE
Looking at NB-IoT over LEO Satellite Systems: Design and Evaluation of a Service-Oriented Solution
The adoption of the NB-IoT technology in satellite communications intends to boost Internet of Things services beyond the boundaries imposed by the current terrestrial infrastructures. Apart from link-level studies in the scientific literature and preliminary 3GPP technical reports, the overall debate is still open. To provide a further step forward in this direction, the work presented herein pursues a novel service-oriented methodology to design an effective solution, meticulously stitched around application requirements and technological constraints. To this end, it conducts link-level and system-level investigations to tune physical transmissions, satellite constellation, and protocol architecture, while ensuring the expected system behavior. To offer a real smart agriculture service operating in Europe, the resulting solution exploits 24 Low Earth Orbit satellites, grouped into 8 different orbits, moving at an altitude of 500 km. The configured protocol stack supports the transmission of tens of bytes generated at the application layer, by also counteracting the issues introduced by the satellite link. Since each satellite has the whole protocol stack on-board, terminals can transmit data without the need for the feeder link. This ensures communication latencies ranging from 16 minutes to 75 minutes, depending on the served number of terminals and the physical transmission settings. Moreover, the usage of the Early Data Transmission scheme reduces communication latencies up to 40%. These results pave the way towards the deployment of an effective proof-of-concept, which drastically reduces the time-to-market imposed by the current state of the art
Terminal LTE flexĂvel
Mstrado em Engenharia Eletrónica e TelecomunicaçõesAs redes móveis estão em constante evolução. A geração atual (4G) de
redes celulares de banda larga e representada pelo standard Long Term
Evolution (LTE), definido pela 3rd Generation Partnership Project (3GPP).
Existe uma elevada procura/uso da rede LTE, com um aumento exponencial
do número de dispositivos móveis a requerer uma ligação à Internet de alto
débito. Isto pode conduzir à sobrelotação do espetro, levando a que o sinal
tenha que ser reforçado e a cobertura melhorada em locais especĂficos, tal
como em grandes conferĂŞncias, festivais e eventos desportivos. Por outro
lado, seria uma vantagem importante se os utilizadores pudessem continuar
a usar os seus equipamentos e terminais em situações onde o acesso a redes
4G é inexistente, tais como a bordo de um navio, eventos esporádicos em
localizações remotas ou em cenários de catástrofe, em que as infraestruturas
que permitem as telecomunicações foram danificadas e a cobertura
temporária de rede pode ser decisiva em processos de salvamento. Assim
sendo, existe uma motivação clara por trás do desenvolvimento de uma
infraestrutura celular totalmente reconfigurável e que preencha as caracterĂsticas mencionadas anteriormente.
Uma possĂvel abordagem consiste numa plataforma de rádio definido por
software (SDR), de cĂłdigo aberto, que implementa o standard LTE e corre
em processadores de uso geral (GPPs), tornando possĂvel construir uma rede
completa investindo somente em hardware - computadores e front-ends de
radiofrequência (RF). Após comparação e análise de várias plataformas LTE
de cĂłdigo aberto foi selecionado o OpenAirInterface (OAI) da EURECOM,
que disponibiliza uma implementação compatĂvel com a Release 8.6 da
3GPP (com parte das funcionalidades da Release 10).
O principal objectivo desta dissertação é a implementação de um User
Equipment (UE) flexĂvel, usando plataformas SDR de cĂłdigo aberto que corram
num computador de placa Ăşnica (SBC) compacto e de baixa potĂŞncia,
integrado com um front-end de RF - Universal Software Radio Peripheral
(USRP). A transmissĂŁo de dados em tempo real usando os modos de duplexagem
Time Division Duplex (TDD) e Frequency Division Duplex (FDD) é suportada e a reconfiguração de certos parâmetros é permitida, nomeadamente
a frequĂŞncia portadora, a largura de banda e o nĂşmero de Resource
Blocks (RBs) usados. AlĂ©m disso, Ă© possĂvel partilhar os dados mĂłveis LTE
com utilizadores que estejam prĂłximos, semelhante ao que acontece com
um hotspot de Wi-Fi. O processo de implementação é descrito, incluindo
todos os passos necessários para o seu desenvolvimento, englobando o port
do UE de um computador para um SBC. Finalmente, a performance da rede
é analisada, discutindo os valores de débitos obtidos.Mobile networks are constantly evolving. 4G is the current generation of
broadband cellular network technology and is represented by the Long Term
Evolution (LTE) standard, de ned by 3rd Generation Partnership Project
(3GPP). There's a high demand for LTE at the moment, with the number
of mobile devices requiring an high-speed Internet connection increasing exponentially.
This may overcrowd the spectrum on the existing deployments
and the signal needs to be reinforced and coverage improved in speci c sites,
such as large conferences, festivals and sport events. On the other hand,
it would be an important advantage if users could continue to use their
equipment and terminals in situations where cellular networks aren't usually
available, such as on board of a cruise ship, sporadic events in remote
locations, or in catastrophe scenarios in which the telecommunication infrastructure
was damaged and the rapid deployment of a temporary network
can save lives. In all of these situations, the availability of
exible and easily
deployable cellular base stations and user terminals operating on standard
or custom bands would be very desirable. Thus, there is a clear motivation
for the development of a fully recon gurable cellular infrastructure solution
that ful lls these requirements.
A possible approach is an open-source, low-cost and low maintenance
Software-De ned Radio (SDR) software platform that implements the LTE
standard and runs on General Purpose Processors (GPPs), making it possible
to build an entire network while only spending money on the hardware
itself - computers and Radio-Frequency (RF) front-ends. After comparison
and analysis of several open-source LTE SDR platforms, the EURECOM's
OpenAirInterface (OAI) was chosen, providing a 3GPP standard-compliant
implementation of Release 8.6 (with a subset of Release 10 functionalities).
The main goal of this dissertation is the implementation of a
exible opensource
LTE User Equipment (UE) software radio platform on a compact
and low-power Single Board Computer (SBC) device, integrated with an
RF hardware front-end - Universal Software Radio Peripheral (USRP). It
supports real-time Time Division Duplex (TDD) and Frequency Division
Duplex (FDD) LTE modes and the recon guration of several parameters,
namely the carrier frequency, bandwidth and the number of LTE Resource
Blocks (RB) used. It can also share its LTE mobile data with nearby users,
similarly to a Wi-Fi hotspot. The implementation is described through
its several developing steps, including the porting of the UE from a regular
computer to a SBC. The performance of the network is then analysed based
on measured results of throughput
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