OPTIMIZAÇÃO INTER-CAMADA PARA PROTOCOLOS DE ENCAMINHAMENTO EM REDES DE SENSORES SEM FIOS

Funder

Organizational Unit

Publications

Combined Hop Count and Received Signal Strength Routing Protocol for Mobility-Enabled WSNs

Publication . Ferro, João M.; Velez, Fernando J.

In this paper, a new routing protocol is proposed for Wireless Sensor Networks (WSNs). The scenario taken is a WSN to be deployed non-intrusively in moving vehicles. WSNs are a class of wireless networks that require specific protocols, whose execution occurs in resource-constrained nodes. As a consequence, the protocol that calculates the optimal path for the packets to reach the sink must be lightweight. In this context, not only the mobility of nodes is challenging, but also the energy consumption. The innovation introduced by this protocol is its combination of the Received Signal Strength Indicator (RSSI) and number of hops to find the best path for the packets, allowing to have the benefits in terms of end-to-end delay and packet delivery ratio. Simulation results show that, when compared with approaches that only take into account the number of hops or RSSI, the protocol increases the number of delivered packets, whilst decreasing the end-to-end delay and the energy consumption. It can also deliver up to 271% more packets, while using less 71% of energy than Flooding.

2012-09Conference object

Open access

Application of Wireless Sensor Networks to Automobiles

Publication . Tavares, Jorge; Velez, Fernando J.; Ferro, João Miguel

Some applications of Wireless Sensor Networks (WSNs) to the automobile are identified, and the use of Crossbow MICAz motes operating at 2.4 GHz is considered together with TinyOS support. These WSNs are conceived in order to measure, process and supply to the user diverse types of information during an automobile journey. Examples are acceleration and fuel consumption, identification of incorrect tire pressure, verification of illumination, and evaluation of the vital signals of the driver. A brief survey on WSNs concepts is presented, as well as the way the wireless sensor network itself was developed. Calibration curves were produced which allowed for obtaining luminous intensity and temperature values in the appropriate units. Aspects of the definition of the architecture and the choice/implementation of the protocols are identified. Security aspects are also addressed.

2008Journal article

Open access

Wearable Sensors for Foetal Movement Monitoring in Low Risk Pregnancies

Publication . Borges, Luís M.; Araújo, Pedro; Lebres, António S.; Rente, Andreia; Salvado, Rita; Velez, Fernando J.; Martinez-de-Oliveira, J.; Barroca, Norberto; Ferro, João Miguel

In low risk pregnancies, the continuous monitoring of the foetal health is based on traditional protocols for counting the foetal movements felt by the mother. Although the maternal perception is a relevant characteristic for the evaluation of the foetal health, this kind of monitoring is hard to accomplish and being subjective can induce into errors due to mother’s anxiety and lack of concentration. Furthermore, the majority of foetal fatalities occur during the last weeks of low risk pregnancies. Therefore, it is important to obtain a universal electronic obstetric tracing, allowing for the identification of sudden changes in the foetus health, by continuously monitoring the foetus movements. The Smart-Clothing project aim has been the development of easy-to-wear belts with a telemedicine system for this purpose. One of the tried solutions is the Flex sensor belt system, which guarantees real-time and continuous foetal monitoring while creating effective interfaces for querying sensor data and store all the medical record (which can later be accessed by health professionals). Another developed belt has piezoelectric sensors incorporated onto it. The piezoelectric sensor belt has shown a high capacity to detect foetal movements, isolating them from external interferences.

2010Book part

Open access