Andre Melon Barroso

Towards Broadband Vehicular Ad-Hoc Networks - The Vehicular Mesh Network (VMESH) MAC Protocol

The current medium access control (MAC) protocol of the wireless access in vehicular environments (WAVE) system is based on IEEE 802.11 distributed coordination function (DCF) and enhanced distributed channel access (EDCA), which have drawbacks in supporting throughput-sensitive non-safety applications in vehicular ad-hoc network (VANET). In order to address the problem, we propose a novel MAC protocol, namely vehicular MESH network (VMESH), which is specifically designed for the control channel (CCH) and multiple service channels (SCHs) structure of WAVE. A synchronized and distributed beaconing scheme is employed in the VMESH protocol for the purposes of neighborhood awareness and dynamic resource reservation on SCHs. The advantages of the VMESH protocol in supporting the throughput-sensitive non-safety applications in VANET are shown through the theoretical analysis comparing to the current WAVE MAC.

Tuning the white light spectrum of light emitting diode lamps to reduce attraction of nocturnal arthropods

Artificial lighting allows humans to be active at night, but has many unintended consequences, including interference with ecological processes, disruption of circadian rhythms and increased exposure to insect vectors of diseases. Although ultraviolet and blue light are usually most attractive to arthropods, degree of attraction varies among orders. With a focus on future indoor lighting applications, we manipulated the spectrum of white lamps to investigate the influence of spectral composition on number of arthropods attracted. We compared numbers of arthropods captured at three customizable light-emitting diode (LED) lamps (3510, 2704 and 2728 K), two commercial LED lamps (2700 K), two commercial compact fluorescent lamps (CFLs; 2700 K) and a control. We configured the three custom LEDs to minimize invertebrate attraction based on published attraction curves for honeybees and moths. Lamps were placed with pan traps at an urban and two rural study sites in Los Angeles, California. For all invertebrate orders combined, our custom LED configurations were less attractive than the commercial LED lamps or CFLs of similar colour temperatures. Thus, adjusting spectral composition of white light to minimize attracting nocturnal arthropods is feasible; not all lights with the same colour temperature are equally attractive to arthropods.

Quantifying Human Indoor Activity Using a Software Radio-Based Radar

Human activity quantification consists of computing a numerical or qualitative metric that indicates the amount of movement a person engaged in a given time interval. Such a metric has important applications in elderly care, wellness and healthcare given the strong empirical relation between a person’s health and his or her activity level. This paper proposes and evaluates methods to quantify the level of human activity in an indoor environment using a continuous wave radar. An experimental evaluation is carried out using a flexible and low-cost software defined radar platform. Results showed a good correlation between the proposed metrics and the motion sequence performed by the subject suggesting that accurate activity quantification in indoor environments can be achieved using a few simple off-body sensors.

Deployment of wireless sensors for remote elderly monitoring

The FP6 project “Wireless Accessible Sensor Populations” (WASP) has developed an end-to-end infrastructure for the deployment and enterprise integration of wireless sensor nodes. The infrastructure is generic and allows for optimisation for a variety of applications by the development of dedicated services that can be distributed over (wearable and ambient) sensor nodes, the WSN gateway, and the enterprise (backend) system. Key to many applications, such as elderly care considered in this paper, is to optimise the battery lifetime of wearable sensor nodes that can be (remotely) customized to the monitoring needs of individual persons and to the quality-of-service demands for offered services. The WASP infrastructure provides practical solutions for these targets and is being validated for realistic elderly care scenarios. These scenarios aim to support the elderly in (semi-) independent Ambient Assisted Living settings as well as to provide health workers with effective means of studying transient deterioration and behavior changes characteristic to the ageing population.

Estimating Indoor Walking Velocity Profile Using a Software Radio-Based Radar

Radar is an attractive technology for long term monitoring of human movement as it operates remotely, can be placed behind walls and is able to monitor a large area depending on its operating parameters. A radar signal reflected off a moving person carries rich information on his or her activity pattern in the form of a set of Doppler frequency components produced by the specific combination of limbs and torso movements. Deploying radars in indoor environments poses however challenges for the interpretation of signals reflected off a moving object due to multipath propagation. Two strategies for the estimation of human walking velocity profile in indoor environments are suggested and discussed. The accuracy of the strategies are evaluated and compared in a field experiment using a flexible and low-cost software defined radar platform. The results obtained indicate that both methods are able to estimate the velocity profile of the person’s translational movement with less than 10% error.

An Addressing Scheme to Support Untraceability in Mobile Ad Hoc Networks

The movement of nodes in mobile ad hoc networks can be inferred by inspecting unique addresses embedded into exchanged messages. If these addresses are fixed, tracing a message to a single source is trivial and movement can be easily uncovered by listening to transmissions in the area of interest. The ease in which such traces can be obtained creates a fertile environment for information misuse and privacy violation. In this paper, a scheme based on address randomization is proposed to reduce traceability in mobile ad hoc networks. The novel feature of the scheme consists of producing new addresses without disrupting communication that relies on keeping neighbor state. This feature is obtained by randomizing addresses progressively, bit by bit, until the desired uncorrelation between old and new address is obtained.