José A. Afonso

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This paper presents LPRT, a new medium access control (MAC) protocol for wireless sensing and actuation systems. Some of the characteristics of the proposed protocol are low power consumption, support for real-time and loss intolerant traffic through contention-free operation and a retransmission scheme, flexibility, and high throughput efficiency. The LPRT(More)
This paper presents experimental results of the communication performance evaluation of a prototype ZigBee-based patient monitoring system commissioned in an in-patient floor of a Portuguese hospital (HPG – Hospital Privado de Guimar~ aes). Besides, it revisits relevant problems that affect the performance of nonbeacon-enabled ZigBee networks. Initially,(More)
This work presents the implementation of a wireless network based on Bluetooth Low Energy (BLE) which enables the integration of multiple sensor nodes into a smartphone-based system in order to monitor the posture of cyclists. The developed posture monitoring system obtains the orientation in space of each body segment in which the sensor nodes are placed(More)
This paper presents an application independent embedded platform for a wireless distributed data acquisition and control system, and describes its application in the scenario of controlling the information processing and communications between sensors and actuators onboard of an autonomous flying robot, in a "fly-by-wireless" approach. The system, which was(More)
Low power consumption and small footprint make ZigBee based devices well suited for personal healthcare applications, being a promising alternative to general care patient monitoring. However, their use in a healthcare facility to monitor several mobile patients poses several difficulties, mainly because this protocol was primarily designed to operate in(More)
The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and(More)
A wireless smart-suit network for monitoring body kinetics, heart and respiratory rate during hidrocinesiotherapy sessions is presented. Sensing modules composed by 3-axis accelerometers, 3-axis magnetometers and interface electronics are used to monitor the body kinetics. Heart rate is measured using an ear clip infrared sensor and respiratory frequency is(More)
Low power and small footprint IEEE 802.15.4/ZigBee based devices are a promising alternative to 802.11a/b/g and proprietary protocols for non-critical patient monitoring under important scenarios such as post-op and emergency rooms. However, their use in a healthcare facility to monitor several mobile patients poses several difficulties, mainly because(More)
This paper presents the project of a mobile cockpit system (MCS) for smartphones, which provides assistance to electric bicycle (EB) cyclists in smart cities' environment. The presented system introduces a mobile application (MCS App) with the goal to provide useful personalized information to the cyclist related to the EB's use, including EB range(More)