Powerless sensor for non-intrusive multi-fiber traffic monitoring

The rapid expansion of fiber optic networks and services, which sees a large number of circuits enabled and disabled each day, introduces a significant complexity for operators to identify fibers that have and do not have attached clients. The service level agreements prevent operators from disconnecting circuits without absolute assurance that no clients are attached. We propose a non-intrusive multichannel fiber detector to facilitate the operation and maintenance of the optical networks. The optical distribution frame usually does not have any power available, thus, the proposed device operates without batteries and is powered by near field communication (NFC). Device installation does not require fiber disconnection or communication interruption, and introduces less than 1 dB insertion loss to detect optical signals down to -30 dBm. In order to read multiple fiber channel status, an NFC-enabled smartphone is used to power the device and measure the signal levels of each channel.info:eu-repo/semantics/publishedVersio

A model to evaluate vertical handovers on JRRM

In a heterogeneous cellular networks environment, users behaviour and network deployment configuration parameters have an impact on the overall Quality of Service. This paper proposes a new and simple model that, on the one hand, explores the users behaviour impact on the network by having mobility, multi-service usage and traffic generation profiles as inputs, and on the other, enables the network setup configuration evaluation impact on the Joint Radio Resource Management (JRRM), assessing some basic JRRM performance indicators, like Vertical Handover (VHO) probabilities, average bit rates, and number of active users, among others. VHO plays an important role in fulfilling seamless users sessions transfer when mobile terminals cross different Radio Access Technologies (RATs) boundaries. Results show that high bit rate RATs suffer and generate more influence from/on other RATs, by producing additional signalling traffic to a JRRM entity. Results also show that the VHOs probability can range from 5 up to 65%, depending on RATs cluster radius and users mobility profile

A model for heterogeneous networks management and performance evaluation

In general, modern networks are analysed by taking several Key Performance Indicators (KPIs) into account, their proper balance being required in order to guarantee a desired Quality of Service (QoS), particularly, cellular wireless heterogeneous networks. A model to integrate a set of KPIs into a single one is presented, by using a Cost Function that includes these KPIs, providing for each network node a single evaluation parameter as output, and reflecting network conditions and common radio resource management strategies performance. The proposed model enables the implementation of different network management policies, by manipulating KPIs according to users' or operators' perspectives, allowing for a better QoS. Results show that different policies can in fact be established, with a different impact on the network, e.g., with median values ranging by a factor higher than two

Estimação de tráfego misto para UMTS

Esta comunicação aborda um simulador que estima tráfego misto em sistemas de terceira geração. Para tal foram usados modelos de fonte de tráfego numa região urbano denso. Para se estimar o tráfego gerado numa grande cidade são considerados os seguintes parâmetros: densidade populacional ao nível das freguesias, 12 serviços e 3 perfis de utilizador (Business, SOHO, Mass Market). Foi ainda estudado o impacto dos serviços mais relevantes na rede, assim como, a sensibilidade da rede ao aumento do tráfego dos utilizadores. O volume do tráfego estimado no total, é muito útil para determinar a melhor localização das estações base. Tendo Lisboa como cenário, foram estimadas para Lisboa 325 estações base UMTS para o ano 2006.info:eu-repo/semantics/publishedVersio

Public mobile wideband networks interference impact assessment on railways GSM-R network

This paper presents a field study relating to the impact that public operator cellular networks such as UMTS (Universal Mobile Telecommunication System), LTE (Long-Term Evolution), and 5G-NR (5G - New Radio) have on railway GSM-R (Global System for Mobile Communications – Railway) networks. The validation of the interference calculation relied on actual network measurements taken along railway lines using a dedicated probe. Emissions from public networks, in some scenarios, have been shown to affect GSM-R networks to a large extent. The developed algorithm is currently being used in real GSM-R network planning to mitigate this negative effect on base station coverage and service performance.info:eu-repo/semantics/publishedVersio

Modelo de propagação para WLANs

As WLANs estão actualmente no topo do mercado das tecnologias de redes de comunicação. São principalmente instaladas em interiores, para onde as tradicionais ferramentas de planeamento não estão ainda vocacionadas. Apesar das preocupações actuais na qualidade de planeamento serem crescentes, os modelos de propagação para interiores nas frequências de trabalho podem ainda ser refinados. Nesta comunicação é proposto um novo modelo de propagação sendo aferido com medidas a 2,4GHz. O modelo de propagação proposto adapta-se a múltiplos cenários, seguindo as medidas efectuadas. Relativamente a outros modelos o seu erro é minimizado.info:eu-repo/semantics/publishedVersio

A 802.11p prototype implementation

This paper presents an IEEE 802.11p full-stack prototype implementation to data exchange among vehicles and between vehicles and the roadway infrastructures. The prototype architecture is based on FPGAs for Intermediate Frequency (IF) and base band purposes, using 802.11a based transceivers for RF interfaces. Power amplifiers were also addressed, by using commercial and in-house solutions. This implementation aims to provide technical solutions for Intelligent Transportation Systems (ITS) field, namely for tolling and traffic management related services, in order to promote safety, mobility and driving comfort through the dynamic and real-time cooperation among vehicles and/or between vehicles and infrastructures. The performance of the proposed scheme is tested under realistic urban and suburban driving conditions. Preliminary results are promising, since they comply with most of the 802.11p standard requirements

DR9.3 Final report of the JRRM and ASM activities

Deliverable del projecte europeu NEWCOM++This deliverable provides the final report with the summary of the activities carried out in NEWCOM++ WPR9, with a particular focus on those obtained during the last year. They address on the one hand RRM and JRRM strategies in heterogeneous scenarios and, on the other hand, spectrum management and opportunistic spectrum access to achieve an efficient spectrum usage. Main outcomes of the workpackage as well as integration indicators are also summarised.Postprint (published version

Energy Efficiency Gains Using VHOs in Heterogeneous Networks

Part 1: Future Heterogeneous NetworkInternational audiencePartially, the future of mobile and cellular networks will be about energy consumption savings, at the network infrastructure side. In the heterogeneous cellular networks environment, these can be achieved based on bandwidth adaptation, discontinuous transmission, relays, or even Base Stations (BSs) shutdown when possible. This paper proposes an approach for power savings using Vertical Handovers (VHOs) among different Radio Access Technologies (RATs), based on Radio Resource Management. The presented solution use a utility function focused on the energy efficiency of a given BS and RAT. An active VHO trigger mechanism is also proposed to provide RF power savings by handover mobile terminals to the most efficient RAT. Based on a power model proposed by the ICT-EARTH project, it is possible to translate RF power savings into system level ones. Results show that VHOs RF power gains range up to 46%, and up to 13% at the BS system level

On the use of okumura-hata propagation model on railway communications

Although Okumura–Hata prediction model has been a widely used model to estimate radio network coverage, its application in railways environment requires validation and additional studies. This paper presents the main results on a study based on measurements campaigns, and identifies significant differences in parameters that characterize the radio propagation in railways environment, for the 900MHz band. Both the propagation slope and standard deviation measured values are presented in this work. For validation, the developed model setup was used in the radio planning process, setting a live Global System for Mobile Communications-Railway pilot network, operating in Portugal.info:eu-repo/semantics/publishedVersio