João Miguel Ferro

Application of Wireless Sensor Networks to Automobiles

Application of Wireless Sensor Networks to Automobiles 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.

Cognitive radio for medical body area networks using ultra wideband

Wearable wireless medical sensors beneficially impact the healthcare sector, and this market is experiencing rapid growth. In the United States alone, the telecommunications services market for the healthcare sector is forecast to increase from

Overview of progress in Smart-Clothing project for health monitoring and sport applications

7.5 billion in 2008 to

Wearable Sensors for Foetal Movement Monitoring in Low Risk Pregnancies

11.3 billion in 2013. Medical body area networks improve the mobility of patients and medical personnel during surgery, accelerate the patients¿ recovery, and facilitate the remote monitoring of patients suffering from chronic diseases. Currently, MBANs are being introduced in unlicensed frequency bands, where the risk of mutual interference with other electronic devices can be high. Techniques developed during the evolution of cognitive radio can potentially alleviate these problems in medical communication environments. In addition, these techniques can help increase the efficiency of spectrum usage to accommodate the rapidly growing demand for wireless MBAN solutions and enhance coexistence with other collocated wireless systems. This article proposes a viable architecture of an MBAN with practical CR features based on ultra wideband radio technology. UWB signals offer many advantages to MBANs, and some features of this technology can be exploited for effective implementation of CR. We discuss the physical and MAC layer aspects of the proposal in addition to the implementation challenges.

A Cross-Layer Multi-Hop Simulator for IEEE 802.11e

Smart Clothing is a project that combines research in textiles materials and wireless sensor and actuator networks in the context of human body monitoring with statistical methods for the data analysis and treatment. This project aims mainly to aid in the monitoring of the foetal movement in the last four weeks of pregnancy. Besides the integration of sensors in the garment there will be needed a hierarchical communication system that allows the delivery of the data collected from the garment that the pregnant is wearing to the doctor. The pregnant can be either at home or in the hospital. In the first stage of the project tests are being made using several types of sensors integrated in a belt in order to choose the one that is more reliable for the detection of foetal movement. Another sensing task is the manufacture of the electrodes for the electrocardiogram (ECG) system. At this point, the electrodes for the ECG are already made and working. The testing of the sensor for the detection of foetal movement is still being done.

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

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.

Interoperability Between IEEE 802.11e and HSDPA: Challenges from Cognitive Radio

In this work we simulate the ad hoc mode of IEEE 802.11e for routing optimisation. We simulate the behaviour of routing algorithms at the network layer by using a custom-made cross-layer network simulator developed by our team, which simultaneously considers the physical and Medium Access Control (MAC) layers. Although the simulator also supports the infrastructure mode, in this paper we focus on the ad hoc feature which was introduced by the authors. We opted for the simulator approach over the theoretical analysis, but we also present a mathematical model for IEEE 802.11 ad hoc networks. Some initial tests were performed by using a simple routing algorithm (to evaluate the behaviour of the system in terms of selection of the path between a source and a destination, and the correctness of the calculated metrics, which include end-to-end delay, packets lost, packets delivered), but more advanced cross-layer design solutions were also tested. When information from the physical and MAC layers is used as an input to the routing algorithm, improvements are achieved in the performance of the network. Several functions were compared and the algorithm that privileges shorter links accounting with the metric “collision rate” achieves the best results. When compared with a standard routing solution, this cross-layer approach allows to increase the number of packets delivered, while not significantly affecting the end-to-end delay of the packets.

Seeking for an Optimal Route in IEEE 802.11e Ad-Hoc Networks

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.

Applications of Wireless Sensor Networks

In this chapter we propose a scenario for interoperability between high-speed downlink packet access (HSDPA) and Wi-Fi. This scenario involves the end-user traveling in a public transportation system and requesting multimedia services to the operator. The interoperability between HSDPA and Wi-Fi (IEEE 802.11e standard) radio access technologies (RATs) is first addressed, a topology in which the user has access to both RATs was considered, together with a common radio resource management (CRRM) to manage the connections. We reached the conclusion that the CRRM enables to increase the system throughput when the load thresholds are set to 0.6 for HSDPA and 0.53 for Wi-Fi. Then, spectrum aggregation is implemented in HSDPA. A resource allocation (RA) algorithm allocates user packets to the available radio resources (in this case Node Bs operating at 2 and 5 GHz are available) in order to satisfy user requirements. Simulation results show that gains up to 22% may be achieved. We have also sought the most efficient way to manage routing packets inside the Wi-Fi network. The proposal which uses links with higher throughputs enables to reach the best results, with gains up to 300% in the packet delivery ratio. Finally, we discuss the challenges that need to be addressed in order to materialise the envisaged cognitive radio scenario in public transportation.

Cross-layer multi-hop simulator for ad-hoc IEEE 802.11e

In this paper we present several different ap- proaches to a routing calculation in an ad-hoc network. By using different weights for each link, each algorithm generates a different path, with its own number of hops and maximum throughput. Tests were performed in our own IEEE 802.11e simulator and the results allow to conclude that the cross-layer approach has advantages over the traditional one. In fact, our proposals delivers up to three times more packets than the standard one, whilst diminishing the end-to-end delay. Results show that the proposal which privileges users with a baud rate near the maximum possible achieves better performance than the others. A baud rate near the maximum corresponds to links with the highest signal to interference-plus-noise ratio. The proposed technique privileges the use of paths with a larger number of hops, and reduces the packet end-to-end delay.