MAC design for WiFi infrastructure networks: a game-theoretic approach

In WiFi networks, mobile nodes compete for accessing a shared channel by means of a random access protocol called Distributed Coordination Function (DCF). Although this protocol is in principle fair, since all the stations have the same probability to transmit on the channel, it has been shown that unfair behaviors may emerge in actual networking scenarios because of non-standard configurations of the nodes. Due to the proliferation of open source drivers and programmable cards, enabling an easy customization of the channel access policies, we propose a game-theoretic analysis of random access schemes. Assuming that each node is rational and implements a best response strategy, we show that efficient equilibria conditions can be reached when stations are interested in both uploading and downloading traffic. More interesting, these equilibria are reached when all the stations play the same strategy, thus guaranteeing a fair resource sharing. When stations are interested in upload traffic only, we also propose a mechanism design, based on an artificial dropping of layer-2 acknowledgments, to force desired equilibria. Finally, we propose and evaluate some simple DCF extensions for practically implementing our theoretical findings.Comment: under review on IEEE Transaction on wireless communication

Evaluation of the Sportsmanship-Aggression Continuum in Youth Football

Given the importance of sport in modern society, it is essential that appropriate instruments are available for the assessment of both fair play and unfair play in the sport of football, particularly in the context of youth football. This research study presents the findings from the implementation of a protocol intended to assess fair play during football matches across three seasons. The study included 64 teams, 1192 players, 64 coaches and 292 referees all of whom were involved in the First Cadet category of the Football Federation of Alava (FFA). The measurement instrument employed was the Record of Football Match Evaluations (RFME) developed by Gimeno, Saenz, Arino and Aznar (2007). The results revealed that there was a high level of fair play at this level of play which extended to referees, coaches and players across the seasons of interest; there was a greater frequency of fair play attitudes relative to unfair play attitudes; home teams that were victorious were judged to have the most favorable fair play attitudes; and there was a negative correlation between perceived fair play and the number of cards shown by referees. The instrument 1) allowed for the effective utilization of a tool to assess fair play in youth football; 2) was effective for use over the course of the season; and 3) provided knowledge about the social agents who initiate inappropriate and unsportsmanlike acts during football matches for of school age youth, which enables consideration of appropriate counter measures. Dada la trascendencia que tiene en nuestra sociedad el deporte, en especial el fútbol desde edades muy tempranas, se hace necesario que los gestores de las competiciones dispongan de herramientas que permitan evaluar los comportamientos de deportividad y no deportividad que se observan en contextos deportivos de fútbol. En la presente investigación, se muestra la implementación de un protocolo de evaluación continua de la deportividad en los partidos de fútbol, durante tres temporadas deportivas. Participaron 64 equipos; 1192 futbolistas, 64 entrenadores y 292 árbitros, de la categoría primera cadete de la Federación Alavesa de Fútbol (F.A.F.). El instrumento de recogida de información utilizado fue el “Registro de Evaluación de Partidos de Fútbol” (REPF) (Gimeno, Sáenz, Ariño y Aznar, 2007). Los resultados re"ejan: puntuaciones positivas, en relación a la deportividad de árbitros, entrenadores y jugadores en cada una de las temporadas evaluadas; una mayor frecuencia de actitudes y conductas deportivas en comparación con las no-deportivas; una mayor percepción de deportividad en aquellos partidos en los que el equipo local es el ganador; y una correlación negativa entre la percepción de deportividad de un partido y el número de tarjetas mostradas por los árbitros. Como conclusión, se puede afirmar que el instrumento que se presenta permite: 1. Utilizar una herramienta de evaluación específica de la deportividad para la disciplina del fútbol en edad escolar; 2. Evaluar la deportividad a lo largo de toda la temporada; 3. Identificar los agentes que presentan comportamientos inadecuados durante la práctica deportiva de los jóvenes deportistas, pudiendo proponer las mejores medidas de intervenció

Evaluation of the Sportsmanship-Aggression Continuum in Youth Football

8 p.[ENG] Given the importance of sport in modern society, it is essential that appropriate instruments are available for the assessment of both fair play and unfair play in the sport of football, particularly in the context of youth football. This research study presents the findings from the implementation of a protocol intended to assess fair play during football matches across three seasons. The study included 64 teams, 1192 players, 64 coaches and 292 referees all of whom were involved in the First Cadet category of the Football Federation of Álava (FFA). The measurement instrument employed was the Record of Football Match Evaluations (RFME) developed by Gimeno, Sáenz, Ariño and Aznar (2007). The results revealed that there was a high level of fair play at this level of play which extended to referees, coaches and players across the seasons of interest; there was a greater frequency of fair play attitudes relative to unfair play attitudes; home teams that were victorious were judged to have the most favorable fair play attitudes; and there was a negative correlation between perceived fair play and the number of cards shown by referees. The instrument 1) allowed for the effective utilization of a tool to assess fair play in youth football; 2) was effective for use over the course of the season; and 3) provided knowledge about the social agents who initiate inappropriate and unsportsmanlike acts during football matches for of school age youth, which enables consideration of appropriate counter measures.[ES] Dada la trascendencia que tiene en nuestra sociedad el deporte, en especial el fútbol desde edades muy tempranas, se hace necesario que los gestores de las competiciones dispongan de herramientas que permitan evaluar los comportamientos de deportividad y no deportividad que se observan en contextos deportivos de fútbol. En la presente investigación, se muestra la implementación de un protocolo de evaluación continua de la deportividad en los partidos de fútbol, durante tres temporadas deportivas. Participaron 64 equipos; 1192 futbolistas, 64 entrenadores y 292 árbitros, de la categoría primera cadete de la Federación Alavesa de Fútbol (F.A.F.). El instrumento de recogida de información utilizado fue el “Registro de Evaluación de Partidos de Fútbol” (REPF) (Gimeno, Sáenz, Ariño y Aznar, 2007). Los resultados re"ejan: puntuaciones positivas, en relación a la deportividad de árbitros, entrenadores y jugadores en cada una de las temporadas evaluadas; una mayor frecuencia de actitudes y conductas deportivas en comparación con las no-deportivas; una mayor percepción de deportividad en aquellos partidos en los que el equipo local es el ganador; y una correlación negativa entre la percepción de deportividad de un partido y el número de tarjetas mostradas por los árbitros. Como conclusión, se puede a#rmar que el instrumento que se presenta permite: 1. Utilizar una herramienta de evaluación especí#ca de la deportividad para la disciplina del fútbol en edad escolar; 2. Evaluar la deportividad a lo largo de toda la temporada; 3. Identi#car los agentes que presentan comportamientos inadecuados durante la práctica deportiva de los jóvenes deportistas, pudiendo proponer las mejores medidas de intervenció

Evaluation of the Sportsmanship-Aggression Continuum in Youth Football

8 p.[ENG] Given the importance of sport in modern society, it is essential that appropriate instruments are available for the assessment of both fair play and unfair play in the sport of football, particularly in the context of youth football. This research study presents the findings from the implementation of a protocol intended to assess fair play during football matches across three seasons. The study included 64 teams, 1192 players, 64 coaches and 292 referees all of whom were involved in the First Cadet category of the Football Federation of Álava (FFA). The measurement instrument employed was the Record of Football Match Evaluations (RFME) developed by Gimeno, Sáenz, Ariño and Aznar (2007). The results revealed that there was a high level of fair play at this level of play which extended to referees, coaches and players across the seasons of interest; there was a greater frequency of fair play attitudes relative to unfair play attitudes; home teams that were victorious were judged to have the most favorable fair play attitudes; and there was a negative correlation between perceived fair play and the number of cards shown by referees. The instrument 1) allowed for the effective utilization of a tool to assess fair play in youth football; 2) was effective for use over the course of the season; and 3) provided knowledge about the social agents who initiate inappropriate and unsportsmanlike acts during football matches for of school age youth, which enables consideration of appropriate counter measures.[ES] Dada la trascendencia que tiene en nuestra sociedad el deporte, en especial el fútbol desde edades muy tempranas, se hace necesario que los gestores de las competiciones dispongan de herramientas que permitan evaluar los comportamientos de deportividad y no deportividad que se observan en contextos deportivos de fútbol. En la presente investigación, se muestra la implementación de un protocolo de evaluación continua de la deportividad en los partidos de fútbol, durante tres temporadas deportivas. Participaron 64 equipos; 1192 futbolistas, 64 entrenadores y 292 árbitros, de la categoría primera cadete de la Federación Alavesa de Fútbol (F.A.F.). El instrumento de recogida de información utilizado fue el “Registro de Evaluación de Partidos de Fútbol” (REPF) (Gimeno, Sáenz, Ariño y Aznar, 2007). Los resultados re"ejan: puntuaciones positivas, en relación a la deportividad de árbitros, entrenadores y jugadores en cada una de las temporadas evaluadas; una mayor frecuencia de actitudes y conductas deportivas en comparación con las no-deportivas; una mayor percepción de deportividad en aquellos partidos en los que el equipo local es el ganador; y una correlación negativa entre la percepción de deportividad de un partido y el número de tarjetas mostradas por los árbitros. Como conclusión, se puede a#rmar que el instrumento que se presenta permite: 1. Utilizar una herramienta de evaluación especí#ca de la deportividad para la disciplina del fútbol en edad escolar; 2. Evaluar la deportividad a lo largo de toda la temporada; 3. Identi#car los agentes que presentan comportamientos inadecuados durante la práctica deportiva de los jóvenes deportistas, pudiendo proponer las mejores medidas de intervenció

ZERO TOUCH PROVISIONING OF RESILIENT ETHERNET PROTOCOL RINGS

When a network device comes online, a fair amount of manual configuration needs to take place before the device is fully functional. Day Zero techniques automate such processes, bringing network devices into a functional state with minimal- to no-touch. However, today a resilient Ethernet protocol (which for convenience may be referred herein to as ‘REP’) does not support Day Zero technologies, since by design there is no support for this requirement at the protocol level. Consequently, current REP ring provisioning requires manual intervention, is time consuming, and involves high operational cost. To address these types of challenges, techniques are presented herein that support configuring REP rings with zero-touch technologies. Aspects of the techniques presented herein introduce a new type-length-value (TLV) encoding scheme to the existing REP Link Status Layer (LSL) protocol data unit (PDU) to carry special flags and Plug and Play (PnP) information

An Algorithmic Framework for Strategic Fair Division

We study the paradigmatic fair division problem of allocating a divisible good among agents with heterogeneous preferences, commonly known as cake cutting. Classical cake cutting protocols are susceptible to manipulation. Do their strategic outcomes still guarantee fairness? To address this question we adopt a novel algorithmic approach, by designing a concrete computational framework for fair division---the class of Generalized Cut and Choose (GCC) protocols}---and reasoning about the game-theoretic properties of algorithms that operate in this model. The class of GCC protocols includes the most important discrete cake cutting protocols, and turns out to be compatible with the study of fair division among strategic agents. In particular, GCC protocols are guaranteed to have approximate subgame perfect Nash equilibria, or even exact equilibria if the protocol's tie-breaking rule is flexible. We further observe that the (approximate) equilibria of proportional GCC protocols---which guarantee each of the $n$ agents a $1/n$-fraction of the cake---must be (approximately) proportional. Finally, we design a protocol in this framework with the property that its Nash equilibrium allocations coincide with the set of (contiguous) envy-free allocations