Contribution to design a communication framework for vehicular ad hoc networks in urban scenarios

The constant mobility of people, the growing need to be always connected, the large number of vehicles that nowadays can be found in the roads and the advances in technology make Vehicular Ad hoc Networks (VANETs) be a major area of research. Vehicular Ad hoc Networks are a special type of wireless Mobile Ad hoc Networks (MANETs), which allow a group of mobile nodes configure a temporary network and maintain it without the need of a fixed infrastructure. A vehicular network presents some specific characteristics, as the very high speed of nodes. Due to this high speed the topology changes are frequent and the communication links may last only a few seconds. Smart cities are now a reality and have a direct relationship with vehicular networks. With the help of existing infrastructure such as traffic lights, we propose a scheme to update and analyse traffic density and a warning system to spread alert messages. With this, traffic lights assist vehicular networks to take proper decisions. This would ensure less congested streets. It would also be possible that the routing protocol forwards data packets to vehicles on streets with enough neighbours to increase the possibility of delivering the packets to destination. Sharing updated, reliable and real-time information, about traffic conditions, weather or security alerts, increases the need of algorithms for the dissemination of information that take into account the main beneffits and constraints of these networks. For all this, routing protocols for vehicular networks have the difficult task to select and establish transmission links to send the data packets from source to destination through multiple nodes using intermediate vehicles efficiently. The main objective of this thesis is to provide improvements in the communication framework for vehicular networks to improve decisions to select next hops in the moment to send information, in this way improving the exchange of information to provide suitable communication to minimize accidents, reduce congestion, optimize resources for emergencies, etc. Also, we include intelligence to vehicles at the moment to take routing decisions. Making them map-aware, being conscious of the presence of buildings and other obstacles in urban environments. Furthermore, our proposal considers the decision to store packets for a maximum time until finding other neighbouring nodes to forward the packets before discarding them. For this, we propose a protocol that considers multiple metrics that we call MMMR (A Multimetric, Map-Aware Routing Protocol ). MMMR is a protocol based on geographical knowledge of the environment and vehicle location. The metrics considered are the distance, the density of vehicles in transmission range, the available bandwidth and the future trajectory of the neighbouring nodes. This allows us to have a complete view of the vehicular scenario to anticipate the driver about possible changes that may occur. Thus, a node can select a node among all its neighbours, which is the best option to increase the likelihood of successful packet delivery, minimizing time and offering a level of quality and service. In the same way, being aware of the increase of information in wireless environments, we analyse the possibility of offering anonymity services. We include a mechanism of anonymity in routing protocols based on the Crowd algorithm, which uses the idea of hiding the original source of a packet. This allowed us to add some level of anonymity on VANET routing protocols. The analytical modeling of the available bandwidth between nodes in a VANET, the use of city infrastructure in a smart way, the forwarding selection in data routing byvehicles and the provision of anonymity in communications, are issues that have been addressed in this PhD thesis. In our research work we provide contributions to improve the communication framework for Vehicular Ad hoc Networks obtaining benefits toenhance the everyday of the population.La movilidad constante de las personas y la creciente necesidad de estar conectados en todo momento ha hecho de las redes vehiculares un área cuyo interés ha ido en aumento. La gran cantidad de vehículos que hay en la actualidad, y los avances tecnológicos han hecho de las redes vehiculares (VANETS, Vehicular Ad hoc Networks) un gran campo de investigación. Las redes vehiculares son un tipo especial de redes móviles ad hoc inalámbricas, las cuales, al igual que las redes MANET (Mobile Ad hoc Networks), permiten a un grupo de nodos móviles tanto configurar como mantener una red temporal por si mismos sin la necesidad de una infraestructura fija. Las redes vehiculares presentan algunas características muy representativas, por ejemplo, la alta velocidad que pueden alcanzar los nodos, en este caso vehículos. Debido a esta alta velocidad la topología cambia frecuentemente y la duración de los enlaces de comunicación puede ser de unos pocos segundos. Estas redes tienen una amplia área de aplicación, pudiendo tener comunicación entre los mismos nodos (V2V) o entre los vehículos y una infraestructura fija (V2I). Uno de los principales desafíos existentes en las VANET es la seguridad vial donde el gobierno y fabricantes de automóviles han centrado principalmente sus esfuerzos. Gracias a la rápida evolución de las tecnologías de comunicación inalámbrica los investigadores han logrado introducir las redes vehiculares dentro de las comunicaciones diarias permitiendo una amplia variedad de servicios para ofrecer. Las ciudades inteligentes son ahora una realidad y tienen una relación directa con las redes vehiculares. Con la ayuda de la infraestructura existente, como semáforos, se propone un sistema de análisis de densidad de tráfico y mensajes de alerta. Con esto, los semáforos ayudan a la red vehicular en la toma de decisiones. Así se logrará disponer de calles menos congestionadas para hacer una circulación más fluida (lo cual disminuye la contaminación). Además, sería posible que el protocolo de encaminamiento de datos elija vehículos en calles con suficientes vecinos para incrementar la posibilidad de entregar los paquetes al destino (minimizando pérdidas de información). El compartir información actualizada, confiable y en tiempo real sobre el estado del tráfico, clima o alertas de seguridad, aumenta la necesidad de algoritmos de difusión de la información que consideren los principales beneficios y restricciones de estas redes. Así mismo, considerar servicios críticos que necesiten un nivel de calidad y servicio es otro desafío importante. Por todo esto, un protocolo de encaminamiento para este tipo de redes tiene la difícil tarea de seleccionar y establecer enlaces de transmisión para enviar los datos desde el origen hacia el destino vía múltiples nodos utilizando vehículos intermedios de una manera eficiente. El principal objetivo de esta tesis es ofrecer mejoras en los sistemas de comunicación vehicular que mejoren la toma de decisiones en el momento de realizar el envío de la información, con lo cual se mejora el intercambio de información para poder ofrecer comunicación oportuna que minimice accidentes, reduzca atascos, optimice los recursos destinados a emergencias, etc. Así mismo, incluimos más inteligencia a los coches en el momento de tomar decisiones de encaminamiento de paquetes. Haciéndolos conscientes de la presencia de edificios y otros obstáculos en los entornos urbanos. Así como tomar la decisión de guardar paquetes durante un tiempo máximo de modo que se encuentre otros nodos vecinos para encaminar paquetes de información antes de descartarlo. Para esto, proponemos un protocolo basado en múltiples métricas (MMMR, A Multimetric, Map-aware Routing Protocol ) que es un protocolo geográfio basado en el conocimiento del entorno y localización de los vehículos. Las métricas consideradas son la distancia, la densidad de vehículos en el área de transmisión, el ancho de banda disponible y la trayectoria futura de los nodos vecinos. Esto nos permite tener una visión completa del escenario vehicular y anticiparnos a los posibles cambios que puedan suceder. Así, un nodo podrá seleccionar aquel nodo entre todos sus vecinos posibles que sea la mejor opción para incrementar la posibilidad de entrega exitosa de paquetes, minimizando tiempos y ofreciendo un cierto nivel de calidad y servicio. De la misma manera, conscientes del incremento de información que circula por medios inalámbricos, se analizó la posibilidad de servicios de anonimato. Incluimos pues un mecanismo de anonimato en protocolos de encaminamiento basado en el algoritmo Crowd, que se basa en la idea de ocultar la fuente original de un paquete. Esto nos permitió añadir cierto nivel de anonimato que pueden ofrecer los protocolos de encaminamiento. El modelado analítico del ancho de banda disponible entre nodos de una VANET, el uso de la infraestructura de la ciudad de una manera inteligente, la adecuada toma de decisiones de encaminamiento de datos por parte de los vehículos y la disposición de anonimato en las comunicaciones, son problemas que han sido abordados en este trabajo de tesis doctoral que ofrece contribuciones a la mejora de las comunicaciones en redes vehiculares en entornos urbanos aportando beneficios en el desarrollo de la vida diaria de la población

Impacto de mecanismos de seguridad en sensores IEEE 802.15.4

En la actualidad son muchos los mecanismos de seguridad que el estándar IEEE 802.15.4 permite a las redes inalámbricas de sensores [1] Dicho estándar define las especificaciones de la Capa de Acceso al Medio y la Capa Física de los dispositivos inalámbricos de área personal. La última revisión corresponde al 2006. Dichas revisiones y actualizaciones son hechas por el grupo de trabajo 802.15. Sin embargo estos mecanismos consumen recursos como memoria y batería, que son un poco limitados en estos dispositivos. Además de contribuir a los retardos en la comunicación. Por lo cual, en el presente trabajo se presenta de manera práctica el impacto que el uso de mecanismos de seguridad tienen en el desempeño de este tipo de redes. Para ello se hizo una comparación de dicho desempeño de manera teórica basándose en lo presentado en [2], con los valores óptimos apegados a lo especificado en el estándar IEEE 802.15.4, en contraste con pruebas reales. Para estas pruebas se hizo uso del sistema operativo TinyOS [3] y de las operaciones de seguridad MAC (Capa de Acceso al Medio) ofrecidas por el chip CC2420 usado en las motas TelosB. Además se presenta el desgaste de la batería, el cual es otro punto importante que se desea conservar en los sensores.Postprint (published version

Performance evaluation of a hybrid sensor and vehicular network to improve road safety

In the last years, wireless networks have become a widely spread type of communication technology and also a challenging scientific area for new fields of research. Many contributions in ad hoc networks, such as WSNs (Wireless Sensor Networks) and VANETs (Vehicular Ad Hoc Networks), have been proposed. Nowadays, the huge amount of cars in transit has raised a big interest in vehicular communication technologies. A new type of network has been developed, named HSVN (Hybrid Sensor and Vehicular Network) in which WSNs and VANETs cooperate with the aim of improving road safety. Recent projects, such as CVIS [1] and COMeSafety [2], are focused on improving the road driving. This type of approaches will warn the driver and the co-pilot of any event occurred in the road ahead, such as traffic jam, accidents, bad weather, etc. This way, the number of traffic accidents may decrease and many lives might be saved. Besides, a better selection of non-congested roads will help to reduce pollution. In addition, other attractive services, such as downloading of multimedia services or Internet browsing, would be easily available through infrastructure along the roadside. Transportation in motorways will be easier, safer and more comfortable for passengers. In this paper a HSVN platform is presented, also a communications protocol between VANETs and WSNs is described and evaluated using the NCTUns [3] simulator.Postprint (published version

Available bandwidth-aware routing in urban vehicular ad-hoc networks

Vehicular communication for intelligent transportation systems will provide safety, comfort for passengers, and more efficient travels. This type of network has the advantage to warn drivers of any event occurred in the road ahead, such as traffic jam, accidents or bad weather. This way, the number of traffic accidents may decrease and many lives could be saved. Moreover, a better selection of non-congested roads will help to reduce pollution. Some other interesting services, such as downloading of multimedia services, would be possible and available through infrastructure along the roadside. Providing multimedia services over VANETs may require a QoS-aware routing protocol that often need to estimate available resources. In this paper, we study the performance, in realistic VANET urban scenarios, of an extension of AODV that includes the available bandwidth estimator ABE [1]. AODV-ABE establishes forwarding paths that satisfy the bandwidth required by the applications. The results, obtained on the NCTUns simulator [2], show that AODVABE could be used in urban-VANETs where vehicles’ speed is moderate.Peer ReviewedPostprint (author’s final draft

Coherent, automatic address resolution for vehicular ad hoc networks

Published in: Int. J. of Ad Hoc and Ubiquitous Computing, 2017 Vol.25, No.3, pp.163 - 179. DOI: 10.1504/IJAHUC.2017.10001935The interest in vehicular communications has increased notably. In this paper, the use of the address resolution (AR) procedures is studied for vehicular ad hoc networks (VANETs). We analyse the poor performance of AR transactions in such networks and we present a new proposal called coherent, automatic address resolution (CAAR). Our approach inhibits the use of AR transactions and instead increases the usefulness of routing signalling to automatically match the IP and MAC addresses. Through extensive simulations in realistic VANET scenarios using the Estinet simulator, we compare our proposal CAAR to classical AR and to another of our proposals that enhances AR for mobile wireless networks, called AR+. In addition, we present a performance evaluation of the behaviour of CAAR, AR and AR+ with unicast traffic of a reporting service for VANETs. Results show that CAAR outperforms the other two solutions in terms of packet losses and furthermore, it does not introduce additional overhead.Postprint (published version

AVISS: Aplicación Adaptativa de Streaming de Vídeo

En este trabajo presentamos AVISS (Adaptive VIdeo-Streaming Application), una aplicación para la transmisión adaptativa de streaming de vídeo en redes móviles ad-hoc (MANET, Mobile Ad-hoc Networks). AVISS pretende ofrecer una mejor Calidad de Experiencia (QoE, Quality of Experience) al usuario final mediante la auto-adaptación a las condiciones cambiantes de operación de la red. Para medir la calidad del vídeo recibido, también se ha definido una nueva métrica llamada Calidad del GoP (QoG, Quality of GoP). Esta métrica se calcula en el destino final en tiempo real y depende de la cantidad y tipo de cuadros de vídeo recibidos por cada GoP (Group of Pictures) transmitido, por lo que está relacionada con la QoE que el usuario final podría percibir. AVISS ha sido implementado utilizando la versión de RTP/RTCP del simulador de redes NCTUns, y sus prestaciones se han evaluado bajo diferentes condiciones de operación en redes MANET, reconocidas por ser altamente dinámicas.------ In this paper we present AVISS (Adaptive VIdeo-Streaming Application), an adaptive Client-Server application for video-streaming over Mobile Ad-hoc NETworks (MANETs). AVISS pretends to offer a better Quality of Experience (QoE) to the end user of the video-streaming system by adapting itself to time-varying operating conditions of the network. In order to measure the quality of the received video, we also define a new metric called Quality of GoP (QoG), which is easy to measure at the destination node, it does not require the original transmitted video as reference and it is related to the QoE end-user could perceive. As a proof of concept, AVISS has been implemented over a modified version of the RTP/RTCP implementation included with the NCTU network simulator (NCTUns) and we have evaluated its performance on simulated MANETs under several different operating conditions.Peer ReviewedPostprint (published version

A Metamodel Proposal for a Web Development Code Generation Tool

Code generation is an important part of Model-Driven Development as well as the abstract representation of the software functionality. One of the strong deficiencies in this paradigm is the lack of research projects regarding to code generation that uses the terminology applied in the industry. In order to ameliorate this scenario, in this work is presented a metamodel proposal for a Web development code generation tool. This proposal is based on the terminology used in the industry for Web development in the region of Sinaloa, México. This is an extension and updated explanation of our work previously presented in a conference

Techniques and Tools for Web Requirements in NDT, UWE and WebML

Requirements Engineering (RE) is one of the serious issues for software construction. In the scientific literature we can find several reasons of this affirmation, is spite of this, most of the development process of new software crash due to wrong requirements phase. Several proposals exist for requirements modelling, analysis and elicitation in Software Engineering (SE), however the current market is focusing on the development of Web and mobile applications, specially using Model-Driven methods, this is the reason why we consider it necessary to know the techniques and tools for requirements modelling, analysis and elicitation applied in Model-Driven Web Engineering in order to know their gaps and current trends to propose new solutions. To do this, the most important methods were selected outside the academic area such as NDT, UWE and WebML. A total of 63 publications from ACM, IEEE, Science Direct, DBLP and World Wide Web had been reviewed

Management of traffic lights for emergency services

U današnje vrijeme razvoj bežične tehnologije omogućuje istraživačima razvijanje komunikacijskih sustava u kojima se vozila koriste kao osnovne jedinice u komunikacijskim mrežama primjenom infrastrukture koja postoji u gradovima. U ovom se radu predstavlja razvoj nove aplikacije u operativnom sustavu Android u svrhu poboljšanja sigurnosti na cestama. Novi koncept poput Smart Cities (pametni gradovi) uključuje inteligentno upravljanje prometom u kojemu bi u svakom trenutku bili na raspolaganju podaci iz Centra za obavijesti o prometu. Cilj je našeg prijedloga upravljanje semaforima iz vozila hitne pomoći (ambulantna, vatrogasna itd.) u hitnim slučajevima, dakle smanjivanje vremena zaustavljanja na križanjima zbog crvenih svjetala. U radu se predstavlja razvoj aplikacije za upravljanje semafora i cilj je osigurati vozačima upravljanje semaforima u hitnim slučajevima. Na kraju razmatramo što je sve potrebno za stvarni razvoj aplikacije. Ova je projekt dobio prvu nagradu za prototip na regionalnoj i nacionalnoj izložbi znanstvenih dostignuća ExpoCiencias 2013 u Meksiku što mu je omogućilo sudjelovanje na London International Youth Science 2014 (LIYSF).Currently, the evolution of wireless technologies has allowed researchers to design communication systems where vehicles are used as first entities to participate in the communication networks using the infrastructure present in cities. In this paper, the development of a new application under the Android operating system as an effort to improve road safety is presented. A new concept, such as Smart Cities includes intelligent traffic management in which data from the Traffic Information Centre infrastructures could be reachable at any point. The goal of this proposal is to manage the traffic lights from inside of the emergency vehicles (as ambulance, fire truck, etc.) in order to minimize the response time in case of an emergency, therefore, reducing the stop time in the intersections due to red lights. Presented in this work is the development of an application for the management of traffic lights, the objective is to provide the control to drivers over the traffic light in the emergency route. Finally we discuss the requirements for the real development of the application. This project obtained the best prototype award in the regional and national science fair in Mexico ExpoCiencias 2013 with which the project was prize winning to participate in the London International Youth Science 2014 (LIYSF)