The emergence of Body Sensor Networks (BSNs) constitutes a new and fast growing trend for the development of daily routine applications. However, in the case of heterogeneous BSNs integration with Vehicular ad hoc Networks (VANETs) a large number of difficulties remain, that must be solved, especially when talking about the detection of human state factors that impair the driving of motor vehicles. The main contributions of this investigation are principally three: (1) an exhaustive review of the current mechanisms to detect four basic physiological behavior states (drowsy, drunk, driving under emotional state disorders and distracted driving) that may cause traffic accidents is presented; (2) A middleware architecture is proposed. This architecture can communicate with the car dashboard, emergency services, vehicles belonging to the VANET and road or street facilities. This architecture seeks on the one hand to improve the car driving experience of the driver and on the other hand to extend security mechanisms for the surrounding individuals; and (3) as a proof of concept, an Android real-time attention low level detection application that runs in a next-generation smartphone is developed. The application features mechanisms that allow one to measure the degree of attention of a driver on the base of her/his EEG signals, establish wireless communication links via various standard wireless means, GPRS, Bluetooth and WiFi and issue alarms of critical low driver attention levels.
In body sensor networks (BSNs), energy-constrained sensors monitor the vital signs of human beings in healthcare applications. Energy consumption is a fundamental issue, since BSNs must operate properly and autonomously for long period of time without battery recharge or replacement. In addition, the human exposure to electromagnetic radiation must be limited. For all these reasons, the energy consumption in BSNs should be minimized. In this paper, sensor and gateway location optimization for BSNs has been analyzed. A mathematical model has been proposed to minimize the energy consumption of the BSN and the heating effects on human tissues. We distinguish between 'in-body' and 'on-body' sensors depending on their location inside or outside the human body, respectively. The theoretical analysis and the numerical results reveal that in in-BSNs the energy consumption can be significantly reduced when the optimal positions of the gateway or the sensors are computed. However, in on-BSNs the energy consumption is not affected by the devices' location. With power control the interferences are minimized and the human exposure to electromagnetic radiation is reduced.
Rebolledo, G.; Reyes, M.; Paszkowicz, S.; Domingo, M.; Skrypchuk, L. IEEE transactions on intelligent transportation systems Vol. 15, num. 4, p. 1850-1854 DOI: 10.1109/TITS.2014.2335151 Data de publicació: 2014-08-01 Article en revista
Emerging applications using body sensor networks (BSNs) constitute a new trend in car safety. However, the integration of heterogeneous body sensors with vehicular ad hoc networks (VANETs) poses a challenge, particularly on the detection of human behavioral states that may impair driving. This paper proposes a detector of human emotions, of which tiredness and stress (tension) could be related to traffic accidents. We present an exploratory study demonstrating the feasibility of detecting one emotional state in real time using a BSN. Based on these results, we propose middleware architecture that is able to detect emotions, which can be communicated via the onboard unit of a vehicle with city emergency services, VANETs, and roadside units, aimed at improving the driver's experience and at guaranteeing better security measures for the car driver.
Congestion control in Underwater Wireless Sensor Networks (UWSNs) is an important but challenging issue. TCP performs very poorly in UWSNs due to its inability to distinguish between packet losses due to congestion and those due to channel error. The existing congestion control protocols developed for terrestrial sensor networks cannot be applied to UWSNs because the characteristics of the underwater channel such as high bit error rates, high attenuation and propagation delays, multipath and Doppler distortion have not been considered.
In this paper, a biologically-inspired congestion control protocol has been proposed for UWSNs based on the ability of marine communities to terminate with phytoplankton blooms and move the system back to equilibrium between species. The proposed distributed algorithm distinguishes between packet losses due to congestion and those due to high link error rates. It eliminates flow starvation and provides flow fairness. The channel effects of underwater propagation on packet losses are captured, the shadow zones are detected and the throughput of the flows from different nodes at the receiver is restored even with channel fading. Consequently, the system goes back to a stable state, where the different event flows coexist. The theoretical analysis and numerical evaluations show the performance of the proposed congestion control protocol in UWSNs.
In this paper, a flexible role-based architecture for Body Sensor Networks (BSNs) is introduced. The proposed non-layered context-aware architecture is application-oriented and able to incorporate future applications. Particular applications have certain requirements. Functional units (roles) instead of protocol layers are designed to perform the required tasks for applications to work properly. The role data of an application is inserted in the role headers of the container and is available for other applications with the same basic, specific or particular roles. Furthermore, the performance of Automatic Repeat Request (ARQ), Forward Error Correction (FEC) block codes and FEC convolutional codes with respect to the throughput efficiency has also been analyzed for a BSN following the proposed role-based architecture. The numerical results show that the proposed role-based architecture outperforms the traditional layered architecture with respect to the throughput efficiency for all error control schemes. FEC block codes are able to maintain a high throughput efficiency over longer distances because the hop length extension technique is applied.
Although acoustic waves are the most versatile and
widely used physical layer technology for underwater wireless
communication networks (UWCNs), they are adversely affected
by ambient noise, multipath propagation, and fading. The large
propagation delays, low bandwidth, and high bit error rates
of the underwater acoustic channel hinder communication as
well. These operational limits call for complementary technologies
or communication alternatives when the acoustic channel
is severely degraded. Magnetic induction (MI) is a promising
technique for UWCNs that is not affected by large propagation
delays, multipath propagation, and fading. In this paper, the
MI communication channel has been modeled. Its propagation
characteristics have been compared to the electromagnetic and
acoustic communication systems through theoretical analysis and
numerical evaluations. The results prove the feasibility of MI
communication in underwater environments. The MI waveguide
technique is developed to reduce path loss. The communication
range between source and destination is considerably extended
to hundreds of meters in fresh water due to its superior bit error
The design of routing protocols for Underwater Wireless Sensor Networks
(UWSNs) poses many challenges due to the intrinsic properties of underwater environments.
In this paper we present DUCS (Distributed Underwater Clustering Scheme), a new GPSfree
routing protocol that does not use flooding techniques, minimizes the proactive routing
message exchange and uses data aggregation to eliminate redundant information. Besides,
DUCS assumes random node mobility and compensates the high propagation delays of the
underwater medium using a continually adjusted timing advance combined with guard time
values to minimize data loss. The theoretical and simulation studies carried out demonstrate
Underwater wireless communication networks
are particularly vulnerable to malicious
attacks due to the high bit error rates, large
and variable propagation delays, and low bandwidth
of acoustic channels. The unique characteristics
of the underwater acoustic
communication channel, and the differences
between underwater sensor networks and their
ground-based counterparts require the development
of efficient and reliable security mechanisms.
In this article, a complete survey of
security for UWCNs is presented, and the
research challenges for secure communication
in this environment are outlined.
In this article a new context-aware architecture
is proposed for the integration of body sensor
networks and social networks through the IP
Multimedia Subsystem. Its motivating application
scenarios are described. The benefits and
main research challenges for an efficient communication
using the proposed architecture are
Shadow zones in Underwater Wireless Sensor
Networks (UWSNs) dramatically impact communication system
performance. In this paper an adaptive topology reorganization
scheme has been proposed that is able to maintain connectivity in
multi-hop three-dimensional UWSNs affected by shadow zones.
The optimal placement for the sensor nodes to minimize the
transmission loss and to maintain the network connectivity has
been found using our proposed mathematical model. The
theoretical analysis and the numerical evaluations reveal that our
proposed scheme reduces the transmission loss under all
propagation phenomena for all water depths in UWSNs and
improves communication quality.
Effective solutions should be devised to handle the effects of shadow zones in
Underwater Wireless Sensor Networks (UWSNs). An adaptive topology reorganization
scheme that maintains connectivity in multi-hop UWSNs affected by shadow zones has
been developed in the context of two Spanish-funded research projects. A mathematical
model has been proposed to find the optimal location for sensors with two objectives: the
minimization of the transmission loss and the maintenance of network connectivity. The
theoretical analysis and the numerical evaluations reveal that our scheme reduces the
transmission loss under all propagation phenomena scenarios for all water depths in
UWSNs and improves the signal-to-noise ratio.
Mecanismo de descubrimiento de gateways para la diferenciación de servicios entre redes ad hoc y redes fijas.
Cuando un nodo localizado en una red ad hoc desea tener acceso a Internet, debe obtener información sobre los gateways disponibles y seleccionar el más apropiado de todos ellos. Se propone un nuevo mecanismo de descubrimiento de gateways adecuado para aplicaciones de tiempo real que ajusta la frecuencia de envío de mensajes de aviso, (Gateway Advertisements, GWADVs), dinámicamente. Este ajuste está relacionado con el porcentaje de fuentes de tiempo real que tienen problemas de calidad de servicio debido a unos retardos extremo a extremo excesivos.
En comparación con los mecanismos de descubrimiento de gateways existentes (proactivo, reactivo e híbrido), el mecanismo propuesto mejora los retardos extremo a extremo, jitter, y tasa de entrega de paquetes para los flujos de tiempo real significativamente; además se reduce el tráfico de señalización (encaminamiento) y no se produce inanición del tráfico de best-effort.
Protocolo de encaminamiento distribuido basado en clusters para redes de sensores submarinas inalámbricas.
Las redes de sensores submarinas inalámbricas presentan muchos desafíos debido a las propiedades de los entornos submarinos, tales como largos retardos de propagación, movilidad de nodos y ancho de banda limitado. Resulta indispensable diseñar protocolos de encaminamiento eficientes con respecto a la energía porque los nodos sensores se alimentan de baterías difíciles de cargar o sustituir. La mayoría de los protocolos de redes de sensores terrestres no pueden ser aplicados porque han sido diseñados para redes estacionarias y los protocolos para redes ad-hoc existentes no funcionan porque utilizan técnicas de inundación o intercambio continuo de mensajes de encaminamiento. Se propone un protocolo de encaminamiento sin GPS que minimiza el intercambio de mensajes de encaminamiento y usa agregación de datos. Asume movilidad de nodos y compensa los retardos de propagación usandoavances temporales combinado con tiempos de guardia.
The main objective of the Euro FGI network is to develop and maintain the most prominent European centre of excellence in Future Generation Internet (FGI) design and engineering, acting as a Collective Intelligence Think Tank, representing a major support for the European industry and leading towards a European leadership in this domain.
The FGI will offer multi-service/multimedia, mobility, service ubiquity and context awareness, convergence (services and fixed-mobile), Quality of Service, variable connectivity (always best connected), spontaneous networking and other capabilities as the norm.
Technology diversity is growing fast and mastering such a heterogeneous environment becomes essential for network designers. This new environment makes obsolete the design and engineering methods and tools currently available and forces the scientific community to develop new principles and methods to design/dimension/control/manage the new multi-technology architectures. These architectures will provide seamless end-to-end connectivity by hiding the technology diversity from service developers and users.
In addition, future high-speed wire-line and wireless access technologies provide instant high bandwidth connectivity making it difficult to forecast demand and thus to apply traditional traffic engineering methods.
For addressing this new environment, Euro-FGI will strengthen the integration of the scientific community activities to fulfil two main goals:
- Overcoming the challenge of technology diversity (vertical and horizontal integration) in the design of efficient and flexible FGI architectures
- Providing innovative traffic engineering approaches adapted to the new requirements and developing the appropriate quantitative methods for analysis, simulation and measurement
Due to the wealth of technologies and tools, achieving the above cited objectives requires the integration of a wide range of research capacities; a role that will be fulfilled by Euro-FGI.
Domingo, M. NETWORKING 2006; Networking Technologies, Services and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications Systems p. 13-24 Presentació treball a congrés
La comunicación entre redes ad hoc y redes basadas en infraestructura resulta esencial para poder extender Internet más allá de su alcance tradicional, a aquellas áreas hasta ahora inaccesibles, permitiendo la utilización de servicios Web y otras muchas aplicaciones en todo momento y lugar. En esta tesis doctoral se abordan dos difíciles retos: intentar proporcionar calidad de servicio extremo a extremo en la comunicación entre una red ad hoc y una red fija, y alargar la supervivencia de la red ad hoc para que dicha comunicación sea lo más estable y duradera posible. Para lograr alcanzar estos objetivos, se ha realizado primeramente un estudio exhaustivo tanto de los modelos de calidad de servicio como de los protocolos de encaminamiento existentes para redes ad hoc aisladas. Fruto de dicho estudio ha surgido una primera contribución que consiste en el diseño e implementación de un protocolo de encaminamiento para la mejora de la supervivencia en una red ad hoc aislada. A partir de esta base se ha podido abordar la diferenciación de servicios en redes ad hoc conectadas con redes fijas; como consecuencia de esta investigación se ha desarrollado una segunda contribución que consiste en el diseño y evaluación de un modelo de diferenciación de servicios que se basa en la cooperación para el mantenimiento de la calidad de servicio entre ambas redes. Finalmente, mediante una tercera contribución, se ha conseguido mejorar la supervivencia de una red ad hoc conectada a una red basada en infraestructura con el diseño e implementación de un protocolo de encaminamiento específicamente creado para tal efecto. Además, se ha demostrado que la incorporación de este protocolo de encaminamiento en una red ad hoc que utiliza un modelo de calidad de servicio basado en la interacción entre la red ad hoc y la red IP fija, no sólo alarga la supervivencia de la red ad hoc sino que además evita un aumento de la congestión y mejora la diferenciación de servicios entre ambas redes. Las simulaciones exhaustivas realizadas sirven para comparar todas estas contribuciones con otras propuestas anteriores, demostrando su efectividad y rendimiento. Las contribuciones presentadas en esta tesis doctoral tienen una singular importancia, pues hasta la fecha no se ha desarrollado ningún modelo de calidad de servicio que permita la interacción y favorezca la cooperación entre una red ad hoc y una red IP fija con el fin de proporcionar calidad de servicio extremo a extremo. Las contribuciones que se aportan demuestran que sí que es posible la diferenciación de servicios entre una red ad hoc y una red IP fija; además, prueban que resulta imprescindible la cooperación e integración de los modelos de calidad de servicio de ambas redes para lograrlo. Este trabajo resulta pionero en estos aspectos y sirve para abrir una nueva línea de investigación con el fin de promover la comunicación entre redes ad hoc y redes fijas.
The communication between wireless ad hoc networks and infrastructure-based networks is essential to extend Internet beyond its traditional scope, to remote inaccessible areas, making Web services available anytime, anywhere. In this PhD thesis two difficult challenges are tackled: to provide end-to-end quality of service in the communication between an ad-hoc and a wired network, and to extend the ad-hoc network survivability to achieve that this communication becomes as stable and lasting as possible. In order to attain these goals, we have firstly done an exhaustive study of the existing quality of service models as well as the routing protocols for isolated ad hoc networks. A first contribution has arisen from this study that is based on the design and implementation of a routing protocol for improving the survivability in an isolated ad hoc network. Under this basis research has been carried out into service differentiation in ad hoc networks connected to fixed networks; as a consequence of this research we have developed the second contribution of this thesis, that consists of the design and evaluation of a service differentiation model based on the cooperation for the quality of service provision between both networks. Finally, by means of a third contribution, we have managed to improve the network survivability of an ad hoc network connected to an infrastructure-based network with the design and implementation of a routing protocol specifically created for this purpose. In addition, we have proved that the incorporation of this routing protocol to an ad hoc network that uses a quality of service model based on the interaction between the ad hoc and the fixed IP network, does not only extend the ad hoc network survivability, but it also avoids congestion increase and improves the service differentiation between both networks. Extensive simulations have been carried out to compare all these contributions with already existing ones, proving their effectiveness and performance. The present contributions in this PhD thesis have a singular importance, since no quality of service model has been developed that enables the interaction and favours the cooperation between an ad-hoc and a fixed IP network with the aim of providing end-to-end quality of service. The contributions demonstrate that it is really possible to differentiate services between an ad hoc and a fixed IP network; moreover, they show that the cooperation and integration of the quality of service models in both networks is unvaluable in order to achieve it. This is a pioneering work in these aspects and it will be very useful to open a new research line with the aim of promoting the communication between ad hoc networks and fixed networks.