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—In this paper, a novel enhancement of the well known ALOHA random access mechanism is presented which largely extends the achievable throughput compared to traditional ALOHA and provides significantly lower packet loss rates. The novel mechanism, called Contention Resolution-ALOHA (CRA), is based on transmitting multiple replicas of a packet in an(More)
This paper describes the design and evaluation of a wearable personal wellness coach system that supports a range of activities including health data collection, interpretation, feedback and self-monitoring. We implemented a wearable computing platform consisting of an array of sensors and application software to motivate users to reach fitness goals and(More)
The International Civil Aviation Organization (ICAO) has defined a mobile IPv6-based Aeronautical Telecommunications Network (ATN/IPS) as a next generation communication network for future Air Traffic Management (ATM). The ATN/IPS will be used with different terrestrial and satellite link technologies for supporting future ATM. In parallel, non-operational(More)
—Contention Resolution Diversity Slotted ALOHA (CRDSA) and its burst degree optimizations (CRDSA++, IRSA) make use of MAC burst repetitions and Interference Cancellation (IC) making possible to reach throughput values as high as T 0.8 in practical implementations, whereas for the traditional slotted ALOHA T 0.37. However, these new techniques introduce a(More)
Future initiatives on enhancing the current air traffic management (ATM) system aim at the integration of various communication systems enabling network centric operations. Therefore, reliable communication protocols and capable communication systems have to be provided in order to realize the eager goals of programs like SESAR and NextGen. Theoretically(More)
Within the next 10-15 years, air-traffic management (ATM) will be primarily based on data communications and voice communication will be mostly used as fallback solution. Furthermore, it is foreseen that IP-based networking solutions for A/G communication will be deployed for cost savings, high reliability and an optimal alignment with the evolution of(More)
—Recent advances in Random Access (RA), improving throughput and loss rates, make the usage of such technique particularly interesting to complement Demand Assigned Multiple Access (DAMA) channels for the return link of satellite systems. In this paper, a novel approach for the integration of the two access strategies aimed at transmission delay(More)