No abstract

Abstract-Real-time physiological monitoring of athletes during sporting events has tremendous potential for maximizing player performance while preventing burn-out and injury, and also enabling exciting new applications such as referee-assist services and enhanced television broadcast. Emerging advanced monitoring devices have the right combination of light weight and unobtrusive size to allow truly non-intrusive monitoring during competition. However their small battery capacities, limited wireless ranges and susceptibility to body effects make real-time data extraction a challenge, particularly in sports with a large playing area. In this work we present the novel application of body area sensor networks to monitoring soccer players in a soccer field. We begin by outlining the challenges in experimental data collection and elaborate on the design choices we have made. Secondly, we show that the inherent characteristics of the operating environment lead to unacceptably high delays for direct transmissions from the players to the base stations. This leads to our third contribution, namely a multi-hop routing protocol that balances between the competing objectives of resource consumption and delay.

Abstract-Wireless sensor networks are increasingly being used for continuous monitoring of patients with chronic health conditions such as diabetes and heart problems. As biomedical sensor nodes become more wearable, their battery sizes diminish, necessitating very careful energy management. This paper proposes feedback-based closed-loop algorithms for dynamically adjusting radio transmit power in body-worn devices, and evaluates their performance in terms of energy savings and reliability as the data periodicity and feedback time-scales vary. Using experimental trace data from body worn devices, we first show that the performance of dynamic power control is adversely affected at long data periods. Next for a given data period we show that modifying the transmit power at too long timescales (around a minute) reduces the efficacy of dynamic power control, while too short a time-scale (few seconds or less) incurs a high feedback signaling overhead. We therefore advocate an intermediate range of time-scales (when permitted by the data periodicity), typically in the few tens of seconds, at which the control algorithms should adapt transmit power in order to achieve maximal energy savings in body-worn sensor devices used for medical monitoring.

Abstract-Live monitoring of athletes during sporting events can help maximise performance while preventing injury, and enable new applications such as referee-assist and enhanced television broadcast services. A major challenge is the extraction of athlete physiological data in real-time, since the radio range of body-worn sensor devices is limited, necessitating multi-hop routing mechanisms. However, little is known about the highly dynamic operating conditions on a soccer field under which communication protocols need to operate.In this work we conduct field experiments in which we outfit first-division soccer players with sensor devices and record their inter-connectivity during a real game. Our first contribution profiles the key properties of the dynamic wireless topologies arising in the soccer field, and highlights the consequences for routing mechanisms. We show that the topology is in general sparse, with short encounters and power-law distributed interencounters. Importantly, the co-ordinated movement of players in the field gives rise to significant correlations amongst links, an aspect that can potentially be exploited by routing. Our second contribution develops a model for generating synthetic topologies that mirror connectivity in a real soccer game, and can be used for simulation studies of routing mechanisms. Its novelty lies in explicitly modelling the underlying auto-correlation and cross-correlation properties of the links, from which derived measures such as inter-encounter times and neighbourhood distributions follow. Our study is an important first step towards understanding and modelling dynamic topologies associated with sports monitoring, and paves the way for the design of real-time routing algorithms for such environments.

Abstract-Body-wearable devices for physiological monitoring are fast becoming a reality -by 2014, 420 million wearable wireless devices are expected to be in use, of which 90% will be for sports and fitness applications. We envisage the use of ultra-lightweight wearable devices for monitoring athletes in field sports such as soccer for quantifying, assessing and improving game performance. To this end, in this paper we present an empirical characterization of the radio signal strength of sensor devices mounted on an athlete's body. We fit simple analytical models to our empirical data, highlighting how the signal degrades with distance as well as orientation of the body. Our model aids in improved protocol design and locationing services that take into account propagation effects of the human body.

No abstract

No abstract

Abstract