2002
Journal article
Open Access
GaliLEO: a simulation tool for LEO satellite constellations
Franck L., Potortì F.
The authors present GaliLEO, a simulator for the transmission of connection-oriented traf.c over a constellation of LEO/MEO (low/medium earth orbit) satellites. Its scope is limited to the satellites and the stations accessing them, without any modelling of the terrestrial network, but inside this scope the goal is to study the performance of satellite-based communication networks from as many possible points of view at the network level. Typical applications include simulation of access techniques, routing policies, and fault management. The simulator is written in Java, and it makes use of dynamic loading to easily integrate user-written modules. A draft manual is available, and a preliminary version of the program was published at the end of 2000.Source: SIMULATION (ONLINE), vol. 78 (issue 9), pp. 543-551
DOI: 10.1177/0037549702078009002
Metrics:
Franck L., Potortì F.
The authors present GaliLEO, a simulator for the transmission of connection-oriented traf.c over a constellation of LEO/MEO (low/medium earth orbit) satellites. Its scope is limited to the satellites and the stations accessing them, without any modelling of the terrestrial network, but inside this scope the goal is to study the performance of satellite-based communication networks from as many possible points of view at the network level. Typical applications include simulation of access techniques, routing policies, and fault management. The simulator is written in Java, and it makes use of dynamic loading to easily integrate user-written modules. A draft manual is available, and a preliminary version of the program was published at the end of 2000.Source: SIMULATION (ONLINE), vol. 78 (issue 9), pp. 543-551
DOI: 10.1177/0037549702078009002
Metrics:
See at:
SIMULATION 
| SIMULATION 
| CNR IRIS | CNR IRIS
2001
Journal article
Open Access
GSn: a new service type for integrated services on the Internet
Gregori E., Marcantonio R., Potortì F.
Network services with deterministic guarantees are based on a worst-case description of user-generated traffic. When designing a policing and scheduling algorithm for guaranteed services on the Internet, accuracy of description of the traffic profile has to be traded with simplicity of implementation. The result of this trade off is often expressed as the number of token buckets required by the service along with the choice of their parameters. The GS type of service proposed by the IETF uses two token buckets both for characterizing the traffic and for policing it. The choice of using only two token buckets is primarily driven by policing costs. In this paper we propose a method that allows the number of token buckets used for characterizing the traffic to be greater than what is actually needed to police it. This means we can obtain an accurate profile of the traffic while keeping policing simple. The method consists of computing a profile of the traffic which involves a number of token buckets of the order of ten, and then doing the policing using only the first token bucket, plus another one which is chosen depending on the delay requirements of the receivers. This paper shows that with this simple enhancement we obtain a guaranteed service whose performance closely approaches the theoretical limits of services with deterministic guarantees.Source: EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, vol. 12, pp. 1-10
DOI: 10.1002/ett.4460120102
Metrics:
Gregori E., Marcantonio R., Potortì F.
Network services with deterministic guarantees are based on a worst-case description of user-generated traffic. When designing a policing and scheduling algorithm for guaranteed services on the Internet, accuracy of description of the traffic profile has to be traded with simplicity of implementation. The result of this trade off is often expressed as the number of token buckets required by the service along with the choice of their parameters. The GS type of service proposed by the IETF uses two token buckets both for characterizing the traffic and for policing it. The choice of using only two token buckets is primarily driven by policing costs. In this paper we propose a method that allows the number of token buckets used for characterizing the traffic to be greater than what is actually needed to police it. This means we can obtain an accurate profile of the traffic while keeping policing simple. The method consists of computing a profile of the traffic which involves a number of token buckets of the order of ten, and then doing the policing using only the first token bucket, plus another one which is chosen depending on the delay requirements of the receivers. This paper shows that with this simple enhancement we obtain a guaranteed service whose performance closely approaches the theoretical limits of services with deterministic guarantees.Source: EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, vol. 12, pp. 1-10
DOI: 10.1002/ett.4460120102
Metrics:
See at:
CNR IRIS | onlinelibrary.wiley.com | European Transactions on Telecommunications | CNR IRIS | www.scopus.com
2005
Conference article
Open Access
Free software and research
Potortì F
Free software licenses are a natural choice in a research environment. In the following, we will try to back this simple statement with some considerations and examples, in an effort to analyse the significant interactions between free software and research.
Potortì F
Free software licenses are a natural choice in a research environment. In the following, we will try to back this simple statement with some considerations and examples, in an effort to analyse the significant interactions between free software and research.
See at:
CNR IRIS | oss2005.case.unibz.it | CNR IRIS
2006
Conference article
Restricted
A tool for packaging and exchanging simulation results
Savic D., Pustisek M., Potortì F.
Storing and exchanging simulation data is a common task among simulation practitioners, but quite often it becomes a challenge as huge quantities of data are not uncommon, and conversion between different formats can become an unwieldy task. After examining some of the needs of the telecommunications simulation community, we describe the architecture of the working prototype of a general purpose archiver and converter for big quantities of simulation data to be released as free software.
Savic D., Pustisek M., Potortì F.
Storing and exchanging simulation data is a common task among simulation practitioners, but quite often it becomes a challenge as huge quantities of data are not uncommon, and conversion between different formats can become an unwieldy task. After examining some of the needs of the telecommunications simulation community, we describe the architecture of the working prototype of a general purpose archiver and converter for big quantities of simulation data to be released as free software.
See at:
fly.isti.cnr.it | CNR IRIS | CNR IRIS
2008
Conference article
Restricted
Practical approaches for software components integration in telecommunications
Rumley S., Savic D., Potortì F., Tomazic S., Gaumier C.
In network engineering as in other areas, sophisticated software tools have been conceived to handle models of increasing complexity. These tools theoretically support a great number of input cases. However, in practice, they are confronted to a limited set of inputs, since too large efforts are required to configure each new input case. Similarly, only a few quantitative metrics are extracted from tool results, whereas the output files could be analyzed in many different ways. The potential of a given tool could thus be decoupled if these preprocessing and post-processing tasks would be wisely automated. In this paper, we focus on these preprocessing and postprocessing operations, and propose a generic execution environment which automates them. This environment permits in particular to assess the influence of various parameters on the final results, and to perform generalized what-if analysis
Rumley S., Savic D., Potortì F., Tomazic S., Gaumier C.
In network engineering as in other areas, sophisticated software tools have been conceived to handle models of increasing complexity. These tools theoretically support a great number of input cases. However, in practice, they are confronted to a limited set of inputs, since too large efforts are required to configure each new input case. Similarly, only a few quantitative metrics are extracted from tool results, whereas the output files could be analyzed in many different ways. The potential of a given tool could thus be decoupled if these preprocessing and post-processing tasks would be wisely automated. In this paper, we focus on these preprocessing and postprocessing operations, and propose a generic execution environment which automates them. This environment permits in particular to assess the influence of various parameters on the final results, and to perform generalized what-if analysis
2006
Contribution to book
Restricted
Packaging simulation results with CostClue
Pustisek M., Savic D., Potortì F.
Researchers performing simulations work in the field of computer telecommunications are often faced with the time-consuming task of converting huge quantities of data to and from different formats. We examine some of the requirements of the telecommunications simulation community and propose an architecture for a general purpose archiver and converter for big quantities of simulation data to be released as free software.
Pustisek M., Savic D., Potortì F.
Researchers performing simulations work in the field of computer telecommunications are often faced with the time-consuming task of converting huge quantities of data to and from different formats. We examine some of the requirements of the telecommunications simulation community and propose an architecture for a general purpose archiver and converter for big quantities of simulation data to be released as free software.
2001
Book
Restricted
GaliLEO: a simulation tool for LEO satellite constellations
Franck L., Potortì F.
We present Galileo, a simulator for the transmission of both connection-oriented and connectionless traffic over a constellation of LEO/MEO (Low / Medium Earth Orbit) satellites. Its scope is limited to the satellites and the stations accessing them, without any modelling of the terrestrial network, but inside this scope the goal is to study the performance of satellite-based communication networks from as many as possible points of view. Typical applications include simulation of access techniques, routing policies, fault management. The simulator is written in Java, and it makes use of dynamic loading to easily integrate user-written modules. A draft manual is available, and a preliminary version of the program will be published by the end of 2000.Source: KLUWER INTERNATIONAL SERIES IN ENGINEERING AND COMPUTER SCIENCE
Franck L., Potortì F.
We present Galileo, a simulator for the transmission of both connection-oriented and connectionless traffic over a constellation of LEO/MEO (Low / Medium Earth Orbit) satellites. Its scope is limited to the satellites and the stations accessing them, without any modelling of the terrestrial network, but inside this scope the goal is to study the performance of satellite-based communication networks from as many as possible points of view. Typical applications include simulation of access techniques, routing policies, fault management. The simulator is written in Java, and it makes use of dynamic loading to easily integrate user-written modules. A draft manual is available, and a preliminary version of the program will be published by the end of 2000.Source: KLUWER INTERNATIONAL SERIES IN ENGINEERING AND COMPUTER SCIENCE
See at:
CNR IRIS | CNR IRIS | www.wkap.nl
2003
Software
Metadata Only Access
Octave fractals
Potortì F.
These are functions for Octave, a high-level language which uses a language very similar to that of Matlab. hurstIDC.m is a function for estimating the Hurst parameter of Hurst noise, commonly known as fractional Brownian noise, or fBn. Network traffic generated as an aggregate of many sources has been shown to behave like fBn. A brief introduction to this topic, with references, can be found in Section 3 of Modeling Ka band scintillation as a fractal process. hurstVTP.m is another function with the same purpose, which uses a different algorithm. In fact, estimating the Hurst parameter is not an easy task, and requires some knowledge of the possible pitfalls. A related function, RMDtraffic.m, is conversely used to generate Gaussian Hurst noise, also called fractional Gaussian noise (fGn for short). fGn can be used to produce synthetic traces representing the traffic generated by the aggregation of multiplicity of traffic sources. The product of this third function is only an approximation of real fGn, for performance reasons, and it only contains nonnegative samples, making the results immediately usable as synthetic traffic traces for simulation purposes.
Potortì F.
These are functions for Octave, a high-level language which uses a language very similar to that of Matlab. hurstIDC.m is a function for estimating the Hurst parameter of Hurst noise, commonly known as fractional Brownian noise, or fBn. Network traffic generated as an aggregate of many sources has been shown to behave like fBn. A brief introduction to this topic, with references, can be found in Section 3 of Modeling Ka band scintillation as a fractal process. hurstVTP.m is another function with the same purpose, which uses a different algorithm. In fact, estimating the Hurst parameter is not an easy task, and requires some knowledge of the possible pitfalls. A related function, RMDtraffic.m, is conversely used to generate Gaussian Hurst noise, also called fractional Gaussian noise (fGn for short). fGn can be used to produce synthetic traces representing the traffic generated by the aggregation of multiplicity of traffic sources. The product of this third function is only an approximation of real fGn, for performance reasons, and it only contains nonnegative samples, making the results immediately usable as synthetic traffic traces for simulation purposes.
See at:
CNR IRIS
2010
Conference article
Open Access
Detection and classification of human arm movements for physical rehabilitation
Guraliuc A. R., Serra A. A., Nepa P., Manara G., Potortì F.
In the latest years, the detection of body posture and activity received a significant interest in the field of the physical rehabilitation aimed at providing advanced medical therapies to patients who have suffered a stroke, joint replacements/reconstructions, amputation, or some motor function disability resulting from Parkinson's disease. Rehabilitation is a dynamic process and the restoration of patients' functional capability to normal requires every day functional activities that need to be monitored and controlled by specialized medical operators. An effective approach is represented by motion capturing systems where some video cameras follow the movements of a number of markers placed on the human body to reconstruct its activity. However, such systems are complex, expensive and require a large number of constitutive elements (cameras and markers)DOI: 10.1109/aps.2010.5561051
Metrics:
Guraliuc A. R., Serra A. A., Nepa P., Manara G., Potortì F.
In the latest years, the detection of body posture and activity received a significant interest in the field of the physical rehabilitation aimed at providing advanced medical therapies to patients who have suffered a stroke, joint replacements/reconstructions, amputation, or some motor function disability resulting from Parkinson's disease. Rehabilitation is a dynamic process and the restoration of patients' functional capability to normal requires every day functional activities that need to be monitored and controlled by specialized medical operators. An effective approach is represented by motion capturing systems where some video cameras follow the movements of a number of markers placed on the human body to reconstruct its activity. However, such systems are complex, expensive and require a large number of constitutive elements (cameras and markers)DOI: 10.1109/aps.2010.5561051
Metrics:
See at:
fly.isti.cnr.it | doi.org | CNR IRIS | ieeexplore.ieee.org | CNR IRIS
2005
Other
Unknown
Free software and research
Potortì F.
Free software licenses are a natural choice in a research environment. In the following, we will try to back this simple statement with some considerations and examples, in an effort to analyse the significant interactions between free software and research.Source: ISTI Technical reports, 2005
Potortì F.
Free software licenses are a natural choice in a research environment. In the following, we will try to back this simple statement with some considerations and examples, in an effort to analyse the significant interactions between free software and research.Source: ISTI Technical reports, 2005
See at: CNR ExploRA
2010
Other
Open Access
universAAL - universAAL brochure, leaflets and web page
Hanke S., Potortì F., Gkaitatzi O., Braun A., Hellenschmidt M., Tazari S., Wolf P., Mosmondor M., Torres Broch M. C., Sabatini C., Petkovic M., Salvi D., Marcussen C. D., Höftberger O.
Deliverable D9.1-A in Work Package 9 is the first deliverable related to the dissemination of the universAAL project objectives and results. The development of a project website, leaflet and brochure aims to create social awareness about the benefits of ambient assisted living (AAL) for elderly people as well as for developers and providers of care services. The first section is the Role of the deliverable that presents the scope and goals of the document the relationships with other work packages and particular deliverables from work packages 8 and 9. To establish the dissemination activities, identification of universAAL stakeholders was required. To be consequent with the stakeholder classification described in work packages 1 and 8, D9.1-A and thus work package 9, adopted the same classification to target the individuals, team, organization with interest in, or concerns relative to the universAAL platform. Section 3 describes the universAAL public website, which aim is to disseminate project results, providing information related to the project and the partners and for the communication among all interested partners. The section presents the website layout, development, contents, navigation, evaluation and maintenance. The structure and mainly the content of the website will adapt to project evolution to better satisfy new dissemination requirements. In addition to the website, a leaflet and brochure have been designed to give a first general picture of the project for a general audience and they are presented in Section 4. They maintain a similar layout to the website and address reader/target users to the website or contact the project coordinator. We also made available a power point presentation to be used and adapted depending on the event where the project is presented. Finally, section 5 outlines the future steps to periodically update the dissemination material as the project progresses. This material will reflect the changes of the dissemination plan (D9.2), project development, needs and results and aligned with new dissemination opportunities.Project(s): UNIVERSAAL
Hanke S., Potortì F., Gkaitatzi O., Braun A., Hellenschmidt M., Tazari S., Wolf P., Mosmondor M., Torres Broch M. C., Sabatini C., Petkovic M., Salvi D., Marcussen C. D., Höftberger O.
Deliverable D9.1-A in Work Package 9 is the first deliverable related to the dissemination of the universAAL project objectives and results. The development of a project website, leaflet and brochure aims to create social awareness about the benefits of ambient assisted living (AAL) for elderly people as well as for developers and providers of care services. The first section is the Role of the deliverable that presents the scope and goals of the document the relationships with other work packages and particular deliverables from work packages 8 and 9. To establish the dissemination activities, identification of universAAL stakeholders was required. To be consequent with the stakeholder classification described in work packages 1 and 8, D9.1-A and thus work package 9, adopted the same classification to target the individuals, team, organization with interest in, or concerns relative to the universAAL platform. Section 3 describes the universAAL public website, which aim is to disseminate project results, providing information related to the project and the partners and for the communication among all interested partners. The section presents the website layout, development, contents, navigation, evaluation and maintenance. The structure and mainly the content of the website will adapt to project evolution to better satisfy new dissemination requirements. In addition to the website, a leaflet and brochure have been designed to give a first general picture of the project for a general audience and they are presented in Section 4. They maintain a similar layout to the website and address reader/target users to the website or contact the project coordinator. We also made available a power point presentation to be used and adapted depending on the event where the project is presented. Finally, section 5 outlines the future steps to periodically update the dissemination material as the project progresses. This material will reflect the changes of the dissemination plan (D9.2), project development, needs and results and aligned with new dissemination opportunities.Project(s): UNIVERSAAL
See at:
CNR IRIS | ISTI Repository | CNR IRIS
2012
Journal article
Restricted
Open minds
Karopka T., Potortì F., Hanke S.
Healthy and active ageing is one of the main challenges for most industrialised nations and a key issue on Europe's agenda for the period 2014-2020. The number of people aged 60 and over in the {EU} is now rising by more than two million every year. This raises the question of how to transform this challenge to our societies into a driver of economy and create a win-win situation? One of the envisioned solutions is the application of assistive technology combined with newly created services to allow people to live an independent life for as long as possible. Research in this area involves many {ICT} related {R&D} disciplines and has attracted much attention in the last couple of years. Several initiatives have emerged to tackle the challenges involved, and significant incremental progress has been made on many fronts. But a major breakthrough, leading to a standardised approach and thereby to widespread adoption, is still not in sight. One of the main problems from the technological point of view is fragmentation. The mission of {AALOA}, the {Ambient Assisted Living Open Association}, is to address this situation by bringing together the resources, tools and people involved in {Ambient Asssisted Living (AAL)} in a single forum that makes it much easier to reach conclusions on provisions needed to achieve progress. A concrete technical objective is to promote a common platform or middleware that is distributed as open source softwareSource: PUBLIC SERVICE REVIEW. HEALTH AND SOCIAL CARE, vol. 31, pp. 1-3
Project(s): UNIVERSAAL
Karopka T., Potortì F., Hanke S.
Healthy and active ageing is one of the main challenges for most industrialised nations and a key issue on Europe's agenda for the period 2014-2020. The number of people aged 60 and over in the {EU} is now rising by more than two million every year. This raises the question of how to transform this challenge to our societies into a driver of economy and create a win-win situation? One of the envisioned solutions is the application of assistive technology combined with newly created services to allow people to live an independent life for as long as possible. Research in this area involves many {ICT} related {R&D} disciplines and has attracted much attention in the last couple of years. Several initiatives have emerged to tackle the challenges involved, and significant incremental progress has been made on many fronts. But a major breakthrough, leading to a standardised approach and thereby to widespread adoption, is still not in sight. One of the main problems from the technological point of view is fragmentation. The mission of {AALOA}, the {Ambient Assisted Living Open Association}, is to address this situation by bringing together the resources, tools and people involved in {Ambient Asssisted Living (AAL)} in a single forum that makes it much easier to reach conclusions on provisions needed to achieve progress. A concrete technical objective is to promote a common platform or middleware that is distributed as open source softwareSource: PUBLIC SERVICE REVIEW. HEALTH AND SOCIAL CARE, vol. 31, pp. 1-3
Project(s): UNIVERSAAL
See at:
CNR IRIS | CNR IRIS | www.publicservice.co.uk
2013
Journal article
Open Access
EvAAL Evaluation workshop
Potortì F.
For the third consecutive year, the Wireless Networks laboratory of the Institute of Information and Technologies (ISTI) of the Italian National Research Council (CNR) was the main organising force behind the EvAAL competition, an effort financed by the universAAL FP7 project and embedded into the AALOA association.Source: ERCIM NEWS, vol. 96, p. 54
Project(s): UNIVERSAAL
Potortì F.
For the third consecutive year, the Wireless Networks laboratory of the Institute of Information and Technologies (ISTI) of the Italian National Research Council (CNR) was the main organising force behind the EvAAL competition, an effort financed by the universAAL FP7 project and embedded into the AALOA association.Source: ERCIM NEWS, vol. 96, p. 54
Project(s): UNIVERSAAL
See at:
ercim-news.ercim.eu | CNR IRIS | CNR IRIS
2013
Other
Restricted
Realizzazione di una GUI per il testing di sistemi di localizzazione device-free passivi
Bianchi A., Milazzo P., Potortì F.
Il tirocinio formativo descritto nella presente relazione si colloca nell'am bito della localizzazione in ambiente indoor ed `e stato svolto nel periodo compreso tra Novembre 2012 e Gennaio 2013 all'Istituto di Scienze e Tecnologie dell'Informazione, area interna al CNR (Consiglio Nazionale delle Ricerche) di Pisa [1]. In particolare, lo scopo del tirocinio `e stato la realizzazione di un'interfaccia grafica di ausilio al testing di un sistema di localizzazione indoor. Prima di vedere i dettagli dell'interfaccia, argomento principale di questa relazione, `e necessario introdurre il sistema di localizzazione in cui si `e andati ad operare.
Bianchi A., Milazzo P., Potortì F.
Il tirocinio formativo descritto nella presente relazione si colloca nell'am bito della localizzazione in ambiente indoor ed `e stato svolto nel periodo compreso tra Novembre 2012 e Gennaio 2013 all'Istituto di Scienze e Tecnologie dell'Informazione, area interna al CNR (Consiglio Nazionale delle Ricerche) di Pisa [1]. In particolare, lo scopo del tirocinio `e stato la realizzazione di un'interfaccia grafica di ausilio al testing di un sistema di localizzazione indoor. Prima di vedere i dettagli dell'interfaccia, argomento principale di questa relazione, `e necessario introdurre il sistema di localizzazione in cui si `e andati ad operare.
2005
Software
Metadata Only Access
Wi-Fi utilities [Release 1.0]
Potortì F.
Functions for Octave for performing computations about Wi-Fi networks (as defined by the IEEE 802.11 standard). Measurements made on a rural open area have shown that the ns-2 two-ray CMU Monarch propagation model is too simplistic. In fact, ns-2 uses a double regression to approximate 2-ray, which is resonable for lower frequencies, such as GSM. For 802.11 frequencies, an exact 2-ray propagation model is more appropriate, as it accounts for holes in the signal strength that happen at the distances where the direct and reflected ray interfere destructively; this phenomenon may altogether prevent correct frame reception. Additionally, frame reception is not a yes-or-no condition based on a threshold power level at the receiver, but rather is well approximated by receiving error probability given by a simple AWGN (additive white Gaussian noise) channel model. wifiper is a function that computes PER (packet error rate) on a Wi-Fi link in rural area, without obstacles, given distance, packet length, speed and other parameters.
Potortì F.
Functions for Octave for performing computations about Wi-Fi networks (as defined by the IEEE 802.11 standard). Measurements made on a rural open area have shown that the ns-2 two-ray CMU Monarch propagation model is too simplistic. In fact, ns-2 uses a double regression to approximate 2-ray, which is resonable for lower frequencies, such as GSM. For 802.11 frequencies, an exact 2-ray propagation model is more appropriate, as it accounts for holes in the signal strength that happen at the distances where the direct and reflected ray interfere destructively; this phenomenon may altogether prevent correct frame reception. Additionally, frame reception is not a yes-or-no condition based on a threshold power level at the receiver, but rather is well approximated by receiving error probability given by a simple AWGN (additive white Gaussian noise) channel model. wifiper is a function that computes PER (packet error rate) on a Wi-Fi link in rural area, without obstacles, given distance, packet length, speed and other parameters.
See at:
fly.isti.cnr.it | CNR IRIS
2005
Other
Restricted
Misure di perdita e ritardo di pacchetti in una rete wi-fi al fine di ottenere un modello del canale a livello di pacchetto
Oligeri G., Potortì F., Giannetti F., Avvenuti M.
O ggetto di questa tesi `e la presentazione di statistiche riguardanti il ritardo e le perdite di frame in una rete wi-fi costituita da due soli calcolatori. Una rete wireless `e costituita da un insieme di calcolatori che comunicano fra loro senza il bisogno di cavi. Esistono diverse tecnologie e standard che permettono il funzionamento delle LAN wireless ma ci`o che si `e diffuso maggiormente `e l'utilizzo della tecnologia radio e degli standard IEEE 802.11b [2] e IEEE 802.11g [3]. L'utiliz- zo del canale radio per la trasmissione dei dati comporta problemi di natura diversa rispetto alla trasmissione su filo, le interferenze che il ricevitore di un segnale radio deve gestire possono essere riassunte in due categorie: le interferenze dovute alle altre reti wireless ma pi `u in generale a qualunque altro dispositivo elettronico, e le interferenze dovute all'ambiente circostante che altera e replica il segnale trasmesso producendo al ricevitore la sovrapposizione di pi `u segnali attenuati e sfasati fra loro. Risulta quindi indispensabile uno studio delle perdite dei dati trasmessi in funzione di parametri quali l'ambiente e la distanza che separa ricevitore e trasmettitore, al fine di ottenere una descrizione statistica del canale.
Oligeri G., Potortì F., Giannetti F., Avvenuti M.
O ggetto di questa tesi `e la presentazione di statistiche riguardanti il ritardo e le perdite di frame in una rete wi-fi costituita da due soli calcolatori. Una rete wireless `e costituita da un insieme di calcolatori che comunicano fra loro senza il bisogno di cavi. Esistono diverse tecnologie e standard che permettono il funzionamento delle LAN wireless ma ci`o che si `e diffuso maggiormente `e l'utilizzo della tecnologia radio e degli standard IEEE 802.11b [2] e IEEE 802.11g [3]. L'utiliz- zo del canale radio per la trasmissione dei dati comporta problemi di natura diversa rispetto alla trasmissione su filo, le interferenze che il ricevitore di un segnale radio deve gestire possono essere riassunte in due categorie: le interferenze dovute alle altre reti wireless ma pi `u in generale a qualunque altro dispositivo elettronico, e le interferenze dovute all'ambiente circostante che altera e replica il segnale trasmesso producendo al ricevitore la sovrapposizione di pi `u segnali attenuati e sfasati fra loro. Risulta quindi indispensabile uno studio delle perdite dei dati trasmessi in funzione di parametri quali l'ambiente e la distanza che separa ricevitore e trasmettitore, al fine di ottenere una descrizione statistica del canale.
2000
Conference article
Open Access
GaliLEO: a simulation tool for LEO satellite constellations
Potortì F., Franck L.
We present Galileo, a simulator for the transmission of both connection-oriented and connectionless traffic over a constellation of LEO/MEO (Low/Medium Earth Orbit) satellites. Its scope is limited to the satellites and the stations accessing them, without any modelling of the terrestrial network, but inside this scope the goal is to study the performance of satellite-based communication networks from as many as possible points of view. Typical applications include simulation of access techniques, routing policies, fault management. The simulator is written in Java, and it makes use of dynamic loading to easily integrate user-written modules. A draft manual is available, and a preliminary version of the program will be published by the end of 2000
Potortì F., Franck L.
We present Galileo, a simulator for the transmission of both connection-oriented and connectionless traffic over a constellation of LEO/MEO (Low/Medium Earth Orbit) satellites. Its scope is limited to the satellites and the stations accessing them, without any modelling of the terrestrial network, but inside this scope the goal is to study the performance of satellite-based communication networks from as many as possible points of view. Typical applications include simulation of access techniques, routing policies, fault management. The simulator is written in Java, and it makes use of dynamic loading to easily integrate user-written modules. A draft manual is available, and a preliminary version of the program will be published by the end of 2000
1989
Other
Open Access
A multimedia traffic generator for high speed network performances evaluation
Calendroni N., Delic I., Potortì F.
No abstract available
Calendroni N., Delic I., Potortì F.
No abstract available
2020
Journal article
Open Access
Beyond Euclidean distance for error measurement in pedestrian indoor location
Mendoza-Silva G. M., Torres-Sospedra J., Potortì F., Moreira A., Knauth S., Berkvens R., Huerta J.
Indoor Positioning Systems suffer from a lack of standard evaluation procedures enabling credible comparisons: this is one of the main challenges hindering their widespread market adoption. Traditionally, accuracy evaluation is based on positioning errors defined as the Euclidean distance between the true positions and the estimated positions. While Euclidean is simple, it ignores obstacles and floor transitions. In this paper, we describe procedures that measure a positioning error defined as the length of the pedestrian path that connects the estimated position to the true position. The procedures apply pathfinding on floor maps using Visibility Graphs or Navigational Meshes for vector maps, and Fast Marching for raster maps. Multi-floor and multi-building paths use information on vertical in-building communication ways and outdoor paths. The proposed measurement procedures are applied to position estimates provided by the Indoor Positioning Systems that participated in the EvAAL-ETRI 2015 competition. Procedures are compared in terms of pedestrian path realism, indoor model complexity, path computation time and error magnitudes. The Visibility Graphs algorithm computes shortest distance paths; Navigational Meshes produces very similar paths with significantly shorter computation time; Fast Marching computes longer, more natural-looking paths at the expense of longer computation time and memory size. The 75th percentile of the measured error differs among the methods from 2.2 m to 3.7 m across the evaluation sets.Source: IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, vol. 70, pp. 1-11
DOI: 10.1109/tim.2020.3021514
Metrics:
Mendoza-Silva G. M., Torres-Sospedra J., Potortì F., Moreira A., Knauth S., Berkvens R., Huerta J.
Indoor Positioning Systems suffer from a lack of standard evaluation procedures enabling credible comparisons: this is one of the main challenges hindering their widespread market adoption. Traditionally, accuracy evaluation is based on positioning errors defined as the Euclidean distance between the true positions and the estimated positions. While Euclidean is simple, it ignores obstacles and floor transitions. In this paper, we describe procedures that measure a positioning error defined as the length of the pedestrian path that connects the estimated position to the true position. The procedures apply pathfinding on floor maps using Visibility Graphs or Navigational Meshes for vector maps, and Fast Marching for raster maps. Multi-floor and multi-building paths use information on vertical in-building communication ways and outdoor paths. The proposed measurement procedures are applied to position estimates provided by the Indoor Positioning Systems that participated in the EvAAL-ETRI 2015 competition. Procedures are compared in terms of pedestrian path realism, indoor model complexity, path computation time and error magnitudes. The Visibility Graphs algorithm computes shortest distance paths; Navigational Meshes produces very similar paths with significantly shorter computation time; Fast Marching computes longer, more natural-looking paths at the expense of longer computation time and memory size. The 75th percentile of the measured error differs among the methods from 2.2 m to 3.7 m across the evaluation sets.Source: IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, vol. 70, pp. 1-11
DOI: 10.1109/tim.2020.3021514
Metrics:
See at:
Recolector de Ciencia Abierta, RECOLECTA | Universidade do Minho: RepositoriUM | CNR IRIS | ieeexplore.ieee.org | ISTI Repository | IEEE Transactions on Instrumentation and Measurement | IEEE Transactions on Instrumentation and Measurement | IEEE Transactions on Instrumentation and Measurement | CNR IRIS | CNR IRIS
2006
Software
Metadata Only Access
Wi-Fi utilities [Release 2.0]
Potortì F.
Functions for Octave for performing computations about Wi-Fi networks (as defined by the IEEE 802.11 standard). Measurements made on a rural open area have shown that the ns-2 two-ray CMU Monarch propagation model is too simplistic. In fact, ns-2 uses a double regression to approximate 2-ray, which is resonable for lower frequencies, such as GSM. For 802.11 frequencies, an exact 2-ray propagation model is more appropriate, as it accounts for holes in the signal strength that happen at the distances where the direct and reflected ray interfere destructively; this phenomenon may altogether prevent correct frame reception. Additionally, frame reception is not a yes-or-no condition based on a threshold power level at the receiver, but rather is well approximated by receiving error probability given by a simple AWGN (additive white Gaussian noise) channel model. wifiper is a function that computes PER (packet error rate) on a Wi-Fi link in rural area, without obstacles, given distance, packet length, speed and other parameters.
Potortì F.
Functions for Octave for performing computations about Wi-Fi networks (as defined by the IEEE 802.11 standard). Measurements made on a rural open area have shown that the ns-2 two-ray CMU Monarch propagation model is too simplistic. In fact, ns-2 uses a double regression to approximate 2-ray, which is resonable for lower frequencies, such as GSM. For 802.11 frequencies, an exact 2-ray propagation model is more appropriate, as it accounts for holes in the signal strength that happen at the distances where the direct and reflected ray interfere destructively; this phenomenon may altogether prevent correct frame reception. Additionally, frame reception is not a yes-or-no condition based on a threshold power level at the receiver, but rather is well approximated by receiving error probability given by a simple AWGN (additive white Gaussian noise) channel model. wifiper is a function that computes PER (packet error rate) on a Wi-Fi link in rural area, without obstacles, given distance, packet length, speed and other parameters.
See at:
fly.isti.cnr.it | CNR IRIS