In recent years, the construction industry has been compelled to explore all possible options for improving the delivery of their products and services. Clients are now expecting a better service and projects that meet their requirements more closely. This has challenged the industry to become more efficient, integrated and more attractive, with benefits for its potential workforce and for society as a whole. Information and communication technologies (ICT) are an enabler to facilitate the improvements required for modernisation. However, due to the geographically dispersed and nomadic nature of the construction industry's workforce, many people are prevented from efficiently and effectively using the ICT tools adopted to date. Mobile technologies providing the 'last mile' connection to the point-of activity could be the missing link to help address the ongoing drive for process improvement. Although this has been a well-researched area, several barriers to mainstream adoption still exist: including a perceived lack of suitable devices; a perceived lack of computer literacy; and the perceived high cost. Through extensive industry involvement, this research has taken the theoretical idea that mobile IT use in the construction industry would be beneficial, a step further; demonstrating by means of a state of the art assessment, usability trials, case studies and demonstration projects that the barriers to mainstream adoption can be overcome. The findings of this work have been presented in four peer-reviewed papers. An ongoing dissemination programme is expected to encourage further adoption.

Com a heterogeneidade de tecnologias de comunicação sem fio presentes na borda de redes de acesso, serviços providos na Internet podem ser acessados de forma quasi ubíqua através de dispositivos móveis ou portáteis. O acesso a esses serviços, contudo, está associado a atrasos e rupturas frequentes na comunicação devido a razões inerentes à mobilidade do dispositivo, como: i) perda de sinal em locais onde há pouca ou nenhuma cobertura de acesso móvel; ii) erros no quadro de dados durante a transmissão e, consequentemente, perdas de pacotes, que podem ser ocasionados por interferência no sinal ou enfraquecimento deste pelo distanciamento do dispositivo em relação à Estação Base; iii) mudanças de endereços IP durante transmissões em andamento causadas pela migração do dispositivo entre diferentes redes. Como consequência, aplicações falham com a ruptura de comunicações orientadas a conexão. Tratar a mobilidade de forma transparente à aplicação é um dos desafios da Computação Móvel e Ubíqua que vem sendo pesquisado ao longo da última década. Soluções foram propostas para operarem desde a Camada de Enlace à Aplicação. Muitas delas, entretanto, exigem modificações na pilha de protocolos TCP/IP e adição de infraestrutura específica de rede no suporte à comunicação fim-a-fim. Além de elevar o custo das etapas de implantação e manutenção, estratégias intrusivas e dependentes de infraestrutura adicional podem não apresentar desempenho satisfatório. Nesse contexto, propomos tratar a mobilidade no nível da própria aplicação através de Sessões de Comunicação que não falham com atrasos e desconexões. Operando somente nos nós-fim e de modo transparente às Camadas adjacentes de Aplicação e Transporte, as sessões não requerem infraestrutura adicional para intermediar ou controlar a comunicação entre pares, tampouco modificações em protocolos legados da pilha TCP/IP. O conceito de Sessões Tolerantes a Rupturas é implementado através de uma API de propósito geral em sistemas Linux que estende a interface de Sockets. A API é, na prática, uma camada transparente sobre o Socket que provê Ciência de Mobilidade à aplicação através de mecanismos para: acompanhar a localização de nós ao longo da duração de uma sessão; detectar rupturas nas transmissões causadas pela mobilidade do nó ou de seu par remoto; suspender e retomar sessões de forma eficiente, segura e confiável. Experimentos conduzidos em ambientes emulados e reais com equipamentos de uso comercial mostram a eficiência das sessões. Além de introduzir baixa degradação na vazão fim-a-fim, rupturas na transmissão podem ser detectadas em microssegundos e sessões suspensas são reabertas em milissegundos. Com um desempenho superior a solução de mobilidade geral da Camada IP, as sessões não necessitam de adaptações de software em equipamentos de rede / Nowadays services available on the Internet can be accessed from mobile devices while they roam across heterogeneous wireless networks. Due to the inherent reasons of device mobility, however, the access to such services is frequently involved with delay and disruptions. The most common reasons are: i) losing radio signal at places where mobile access coverage area is not available; ii) frame error, losses, and fading on the radio signal when the mobile device moves away from the Base Station; iii) changes on the devices IP address over ongoing transmission, while the mobile node migrates among different wireless networks. As result, networked application fails with disruptions on TCP connections established in the mobile users path. Handling seamlessly mobility on the Internet is a technical challenge of the Mobile Computing Paradigm. It has been widely researched over the last decade. Several solutions have been proposed to work from the Link Layer to the Application Layer. Most of them, however, work intrusively and require modifications in the classical TCP/IP protocol stack, as well as rely on additional network infrastructure to support mobile end-to-end communication. Besides increasing the cost of deployment and maintenance, intrusive and infrastructure dependent strategies may not present suitable performance. In this sense, we devised an architecture to handle mobility at the Application level by means of communication sessions that do not fail with delay, disruption or disconnection. Such sessions work only at the end-systems in a such way that: are fully transparent to the adjacent layers of Transport and Application; do not require additional network infrastructure to forward and manage the communication between two mobile peers; and do not impose any modification on the legacy protocols from the TCP/IP stack. The concept of Disruption-Tolerant Sessions is implemented in Linux by means of a general purpose API extended from the Socket interface. Such API is a transparent layer placed on top of the Socket to provide mobility awareness to the Application Layer. To do so, session services are provided for: tracking mobile peers along the session duration; detecting disruptions over TCP connection caused by mobility of the local or remote peer; suspending and resuming sessions with efficiency, security and reliability. Experiments conducted in emulated and real systems (off-the-shelf hardware and open source software) showed the desired efficiency. Besides introducing little overhead on the goodput, disruptions are detected in a range of microseconds and suspended sessions are resumed in milliseconds. With performance greater than the general IP layer mobility solution, the proposed sessions do not require software adaptation in the core of the network infrastructure

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-07-14T12:32:09Z No. of bitstreams: 1 George Almeida De Oliveira_.pdf: 1203626 bytes, checksum: 54258ab2dd96b3f2309b53d61fd0ce0f (MD5) / Made available in DSpace on 2016-07-14T12:32:09Z (GMT). No. of bitstreams: 1 George Almeida De Oliveira_.pdf: 1203626 bytes, checksum: 54258ab2dd96b3f2309b53d61fd0ce0f (MD5) Previous issue date: 2016-03-21 / Nenhuma / Com a popularização no mercado de consumo de wearables, ou dispositivos vestíveis, a computação móvel e ubíqua vem se tornando presente em diversas áreas como educação, comércio e entretenimento. Na área da saúde estes dispositivos têm um importante papel, pois contam com sensores para captura de sinais fisiológicos, como por exemplo, medir a temperatura corporal e batimentos cardíacos do usuário. Em muitos casos não há qualquer padronização ou comunicação entre os diferentes sistemas de cuidados ubíquos que administram os dados fisiológicos do usuário. Esse trabalho apresenta uma proposta para gerenciamento de históricos de contextos fisiológicos através de um modelo denominado GECONFI. O modelo suporta a coleta de dados através de aplicações que utilizam dispositivos e sensores de monitoramento, também define uma ontologia para o domínio de contextos fisiológicos. Esse trabalho apresenta o uso de três aplicações integradas ao GECONFI que permitiram avaliar e testar os serviços disponibilizados pelo modelo. A primeira aplicação chamada SiCuide foi aplicada com treze pacientes e um enfermeiro, que apresentaram pareceres positivos em relação a sua utilidade para o monitoramento fisiológico dos usuários. Os outros dois sistemas denominados FitBurn e Heart-Control foram aplicados em um cenário baseado em sensibilidade a contexto permitindo o acesso compartilhado de uma mesma trilha. Os resultados obtidos mostraram a viabilidade para que outros sistemas realizem a administração de históricos contextuais de maneira genérica através do modelo proposto. / With the popularization in wearables market, or wearable devices, the mobile and ubiquitous computing is becoming present in areas such as education, commerce and entertainment. In healthcare these devices have an important role, as have sensors for capturing physiological signals, such as measuring the body temperature and heart rate of the user. In many cases there´s no standardization or communication between different Ubiquitous care systems that manage the physiological user data. This work presents a proposal for historical contexts of physiological management through a model called GECONFI. The model supports data collection through applications that use devices and monitoring sensors, defines an ontology for the domain of physiological contexts. This work presents the use of three integrated applications to GECONFI, that allowed evaluate and test the services provided by the model. The first application called SiCuide was applied with thirteen patients and a nurse, who showed positive opinions regarding its usefulness for physiological monitoring of users. The other two systems called FitBurn and Heart-Control were applied in a scenario based on sensitivity to context allowing shared access to the same track. The results showed the feasibility for other systems to perform the administration of contextual historical generically through the proposed model.

Les dispositifs mobiles sont aujourd’hui omniprésents dans notre quotidien. Leurs évolutions technologiques ainsi que les moyens de communication toujours plus rapides font que les utilisateurs manipulent toujours plus d’informations sur leurs dispositifs mobiles, modifiant ainsi l’usage qu’ils en font, et remplaçant petit à petit les ordinateurs de bureau. Cependant les dispositifs mobiles ne s’utilisent pas de la même manière que les ordinateurs de bureau et doivent faire face à des contraintes qui leur sont propres. En particulier, les écrans de taille réduite ne permettent pas d’afficher autant d’information que sur l’écran d’un ordinateur de bureau. De plus, ces écrans, tactiles pour la plupart, sont utilisés à la fois comme périphérique d’entrée et de sortie, entraînant ainsi des problèmes d’occultation d’une partie de l’écran lors de l’interaction. Ces constats et limitations posent ainsi le problème de la visualisation interactive de grandes quantités d’information sur dispositifs mobiles.Le problème s’articule donc selon deux axes fortement liés : d’une part la visualisation d’information et d’autre part l’interaction sur dispositifs mobiles. Pour le premier axe, nous nous sommes intéressés aux techniques de visualisation permettant de visualiser à la fois une vue globale de l’espace d’information et une sous-partie détaillée de celui-ci. En effet, visualiser uniquement une sous-partie de l’espace d’information rend sa compréhension difficile du fait du manque de contexte. A l’inverse, visualiser l’espace d’information complet à l’écran le rend illisible.Pour le second axe, nous nous sommes interessés aux techniques d’interaction pour naviguer dans l’espace d’information. En effet, la variété des capteurs disponibles aujourd’hui dans les dispositifs mobiles définit un large espace de possibilités en termes de modalités d’interaction.Nos travaux apportent deux types de contribution : conceptuelles et pratiques. Nous présentons tout d’abord un espace de conception des modalités de navigation en l’instanciant au cas des dispositifs mobiles : cet espace permet de décrire, comparer et concevoir des modalités d’interaction pour la tâche de navigation. Nous présentons ensuite un modèle conceptuel de navigation multimodale permettant de naviguer dans un espace d’information multi-échelles.Basé sur un état de l’art des techniques de visualisation sur dispositifs mobiles, nous avons conçu et évalué expérimentalement une technique de visualisation bifocale. Enfin, en nous reposant sur deux espaces conceptuels et l’état de l’art des modalités d’interaction sur dispositifs mobiles, nous proposons plusieurs techniques d’interaction multimodale conçues et évaluées expérimentalement pour naviguer dans un espace d’information multi-échelles. / Mobile devices are now ubiquitous in everyday computing. Technological advances and increasing mobile network performance allow users to manipulate more and more information on their mobile devices, changing the use they make of these types of devices, which are gradually replacing desktop computers. However mobile devices are not used in the same way as desktops and face specific constraints. In particular, smaller screens fail to display as much information as a computer screen. In addition, these screens, mostly tactile, are used as both input and output devices, leading to occlusion of a portion of the screen during touch interaction. These findings and limitations give rise to the problem of interactive visualization of large amounts of information on mobile devices.We addressed this problem by considering two related research axes: on the one hand information visualization and on the other hand interaction on mobile devices.For the first axis, we focused on visualization techniques that provide an overview of the information space and a detailed subset of it. Indeed, only one view of a subset of the information space makes it difficult to understand it because of the lack of context. Conversely, visualizing the complete information space on the screen of a mobile device makes it unreadable.For the second axis, we studied interaction techniques for navigating an information space. Facing the variety of sensors available in todays mobile devices, there is a vast set of possibilities in terms of interaction modalities.We provide two types of contribution: conceptual and practical.First we present a design space of navigation techniques on mobile devices: this design space enables us to describe, compare and design interaction modalities for the task of navigation in an information space. Second we propose a conceptual model of multimodal navigation for navigating a multiscale information space.Based on a state of the art of visualization techniques on mobile devices, we designed, developed and experimentally tested a bifocal view on a mobile device. By relying on our design space and by operationalizing our conceptual model of navigation, we designed developed and experimentally compared several multimodal interaction techniques for navigating a multiscale information space.

A maioria dos casos de Lesões por Pressão são evitáveis desde que os pacientes em risco sejam identificados precocemente e haja uma correta definição de estratégias de prevenção. Quando as medidas preventivas não são suficientes e surge uma lesão é imprescindível uma correta avaliação e monitoramento da sua evolução. No entanto, a avaliação e monitoramento baseados apenas no olhar e documentação manual do profissional de saúde são subjetivos e muitas vezes imprecisos. As Tecnologias da Informação e Comunicação podem auxiliar nesse sentido, pois essas ferramentas possibilitam a divulgação e atualização de conhecimentos, além de possuírem ferramentas que apoiam a tomada de decisão na prática clínica. Neste espoco, esta pesquisa teve por objetivo desenvolver e avaliar um sistema computacional para gerenciar o cuidado e os indicadores relacionados às lesões por pressão. Trata-se de um estudo aplicado, metodológico e descritivo do tipo coorte prospectivo. A pesquisa foi realizada em etapas que envolveram o desenvolvimento de um sistema computacional, composto por um aplicativo e um sistema web, e testar na prática clínica essa ferramenta. O aplicativo auxilia na avaliação beira-leito do risco do paciente para desenvolver lesão por pressão, sugere cuidados preventivos personalizados e, se o paciente possuir lesão, auxilia na avaliação e registro do estado da lesão por meio de um algoritmo de processamento de imagens. O sistema web, realiza o armazenamento e processamento dos dados baseado nas avaliações beira-leito, nesse sistema é possível consultar estatísticas, tais como incidência, área de tecidos lesado, tempo médio de permanência na unidade, entre outras. Para testar na prática clínica, utilizou-se o sistema em duas Unidades de Terapia Intensiva durante o período de 60 dias, nesse período 126 pacientes foram acompanhados desde sua internação até alta, transferência ou óbito. A pesquisa demonstrou que, apesar das unidades estudadas apresentarem taxas de incidências semelhantes, quando considerado o tempo de internação dos pacientes e área da lesão, observou-se uma significativa diferença entre as unidades. Ainda, nos testes realizados com os usuários finais, o sistema computacional se mostrou altamente preciso e confiável, comprovando sua qualidade técnica e funcional. Neste sentido, o sistema computacional desta pesquisa pode ser uma ferramenta potencial para auxiliar na assistência aos pacientes institucionalizados e no monitoramento de indicadores relacionados as lesões por pressão. Ainda, espera-se que este trabalho contribua para a ampliação de pesquisas cujos objetos de estudo sejam o desenvolvimento de softwares para a saúde / Most cases of Pressure Injury are preventable as long as patients at risk are early identified and strategies for prevention are correctly defined. When preventive measures are not enough and an injury arises, a correct assessment and monitoring of its evolution is essential. However, evaluation and monitoring based only on the healthcare professional\'s observation and manual record is subjective and often inaccurate. The Information and Communication Technologies can help this issue, since these tools allow the dissemination and updating of knowledge, besides having tools that support decision making in clinical practice. In this context, this research aimed to develop and evaluate a computational system to manage care and indicators related to pressure injuries. It is an applied, methodological and descriptive study of the prospective cohort type. The research was carried out in stages that involved the development of a computational system, composed of an application and a web system, and the test in the clinical practice of this tool. The application assists in assessing the patient\'s risk of developing pressure injury, suggests personalized preventive care and, if the patient has an injury, assists in assessing and recording the lesion\'s condition through a digital image processing algorithm. The web system performs data storage and processing based on bedside assessments, which makes it possible to consult statistics such as incidence, area of damaged tissue, average time of permanence in the unit, among others. In the clinical practice test, the system was used in two Intensive Care Units during a 60-day period. During this period, 126 patients were followed from their hospitalization until discharge, transference or death. The research showed that, although the units studied presented similar incidence rates, when considering the length of hospital stay and the area of the lesion, a significant difference was observed between the units. Furthermore, in the tests performed with the application users, the computational system proved to be highly accurate and reliable, proving its technical and functional quality. In this sense, the computational system of this research can be a potential tool to assist healthcare professionals to care of patients and to monitor indicators related to pressure injuries. Still, it is expected that this work contributes to the expansion of research whose objectives are the development of healthcare softwares

This research is motivated by the recent developments in the Internet Engineering Task Force (IETF) to support seamless integration of moving networks deployed in vehicles to the global Internet. The effort, known as Network Mobility (NEMO), paves the way to support high-speed Internet access in mass transit systems, e.g. trains; buses; ferries; and planes; through the use of on-board mobile routers embedded in the vehicle. One of the critical research challenges of this vision is to achieve high-speed and reliable back-haul connectivity between the mobile router and the rest of the Internet. The problem is particularly challenging due to the fact that a mobile router must rely on wireless links with limited bandwidth and unpredictable quality variations as the vehicle moves around. In this thesis, the multi-homing concept is applied to approach the problem. With multi-homing, mobile router has more than one connection to the Internet. This is achieved by connecting the mobile router to a diverse array of wireless access technologies (e.g., GPRS, CDMA, 802.11, and 802.16) and/or a multiplicity of wireless service providers. While the aggregation helps addressing the bandwidth problem, quality variation problem can be mitigated by employing advanced traffic engineering techniques that dynamically control inbound and outbound traffic over multiple connections. More specifically, the thesis investigates traffic engineering solutions for mobile networks that can effectively address the performance objectives, e.g. maximizing profit for mobile network operator; guaranteeing quality of service for the users; and maintaining fair access to the back-haul bandwidth. Traffic engineering solutions with three different levels of control have been investigated. First, it is shown, using detailed computer simulation of popular applications and networking protocols(e.g., File Transfer Protocol and Transmission Control Protocol), that packet-level traffic engineering which makes decisions of which Internet connection to use for each and every packet, leads to poor system throughput. The main problem with packet-based traffic engineering stems from the fact that in mobile environment where link bandwidths and delay can vary significantly, packets using different connections may experience different delays causing unexpected arrivals at destinations. Second, a maximum utility flow-level traffic engineering has been proposed that aims to maximize a utility function that accounts for bandwidth utilization on the one hand, and fairness on the other. The proposed solution is compared against previously proposed flow-level traffic engineering schemes and shown to have better performance in terms of throughput and fairness. The third traffic engineering proposal addresses the issue of maximizing operator?s profit when different Internet connections have different charging rates, and guaranteeing per user bandwidth through admission control. Finally, a new signaling protocol is designed to allow the mobile router to control its inbound traffic.

There is a growing range of IP-based data and voice applications using mobile devices (e.g. 3rd , 4th generation mobile phones and PDAs) and new access technologies (e.g. Bluetooth, 802.11, GPRS, ADSL). This growth is driving a desire to support mobility at the IP level � in other words, allowing an IP host to keep on communicating with other hosts while roaming between different IP subnetworks. Mobile IPv6 allows hosts to move their physical and topological attachment points around an IPv6 network while retaining connectivity through a single, well-known Home Address. Although Mobile IPv6 has been the subject of simulation studies, the real-world dynamic behavior of Mobile IPv6 is only gradually being experimentally characterised and analysed. This thesis reviews the use of Mobile IPv6 to support mobility between independent 802.11b-attached IPv6 subnets, and experimentally measures and critically evaluates how long an end to end IP path is disrupted when a Mobile IPv6 node shifts from one subnetwork to another (handoff time). The thesis describes the development of an experimental testbed suitable for gathering real-world Mobile IPv6 handoff data using publicly available, standards compliant implementations of Mobile IPv6. (An open-source Mobile IPv6 stack (the KAME release under FreeBSD) was deployed). The component of handoff time due to 802.11b link layer handoff is measured separately to assess its impact on the overall Mobile IPv6 handoff time. Using Mobile IPv6 handoff results, the likely performance impact of Mobile IPv6 handoff on a common webcam application and a bulk TCP data transfer is also evaluated. The impact of handoff on these applications clearly shows that a default Mobile IPv6 environment would be highly disruptive to real-time and interactive applications during handoff events, even if the underlying link-layer handoff was instantaneous.

The future Internet will need to cater for an increasing number of powerful devices and entire groups of networks to roam in heterogeneous access networks. The current approach towards meeting such requirements, which is to retrofit mobility solutions to different layers of the protocol stack, has given rise to an increasingly fragmented network control layer. Furthermore, retrofitting solutions in an ad-hoc manner to the protocol stack does not provide consistent support from the network to different applications. This lack of a common control layer for facilitating roaming in heterogeneous networking environments represents a crucial challenge both technically and from a user perspective. To this end, a novel mobility architecture forms the basis and the first part of this dissertation. The work on investigating current network mobility solutions and improving these solutions if deemed necessary, in order to reuse within the novel mobility architecture constitutes the second part of this dissertation. The IETF standard protocol for network mobility was implemented and its performance was analysed on a real networking environment. This enabled to identify problems in the standard which affect the handover and routing performance. To address the identified routing and protocol header overheads of the standard network mobility protocol a novel optimal routing framework, OptiNets was proposed. To address the handover latency issues, optimizations to IPv6 network attachment were incorporated and also an access technology independent multiple interface Make-Before-Break handover mechanism was proposed. The viability of the OptiNets framework and the handover optimizations were demonstrated by analysis and by implementation. A more general external factor that affects the performance of mobile networks which is bandwidth scarcity of Wireless Wide Area Networks was addressed, by proposing a bandwidth fuelling architecture for on-board mobile networks. The feasibility of the bandwidth fuelling architecture was analysed by implementing a prototype and evaluating its performance.

Les nouvelles technologies en matière d'accès à l'information, de communication sans-fil et de localisation d'informations ouvrent la voie à des innovations majeures dans l'utilisation des systèmes informatiques. Ces avancées permettent d'imaginer de nouveaux usages informatiques dont la mise en œuvre motive le développement de méthodes de conception appropriées. Plus particulièrement, l'informatique mobile combine désormais des enjeux conceptuels tels que l'accès à des services par un utilisateur en mobilité, la généralisation d'outils de localisation, la compréhension de systèmes complexes par un public non-expert ou l'importante variabilité des situations d'exécution. Cette thèse propose un cadre de conception qui adresse certains des enjeux pour la mobilité des systèmes d'information. Dans cette perspective, les attentes des utilisateurs et les contraintes technologiques inhérentes à la mobilité des constituants du système définissent un espace contextuel dont les dimensions sont prises en compte dès les premières étapes de la conception. Le modèle proposé établit comme point d'entrée une description de l'espace géographique du système pour différencier un ensemble de contextes d'exécution. L'énoncé de ces contextes permet de corréler les attentes des utilisateurs avec les capacités techniques de la plate-forme et d'offrir le niveau fonctionnel le plus acceptable dans une situation donnée. Dans un second temps, les différentes fonctionnalités et les données mises en œuvre dans chaque contexte d'exécution peuvent être ordonnées ou filtrées afin d'optimiser la présentation des informations aux utilisateurs. Ces recommandations sont produites par l'analyse conjointe des préférences d'utilisateurs selon leurs interactions et leurs comportements spatiaux. Deux cadres expérimentaux viennent illustrer les propositions du modèle. La conception d'un système mobile de suivi de compétition nautique prend en compte différents contextes d'exécution et adapte un niveau de service à des situations dégradées. Un système de documentation et de visite de campus illustre les algorithmes de recommandation et affine la présentation d'informations localement à chaque contexte d'exécution.

In this thesis, we consider wireless ad hoc and sensor networks where energy matters. Indeed, sensor nodes are characterized by a small size, a low cost, an advanced communication technology, but also a limited amount of energy. This energy can be very expensive, difficult or even impossible to renew. Energy efficient strategies are required in such networks to maximize network lifetime. We distinguish four categories of strategies: 1. Energy efficient routing, 2. Node activity scheduling, 3. Topology control by tuning node transmission power and 4. Reduction of the volume of information transferred. Our contribution deals with energy efficient routing and node activity scheduling. For energy efficient routing, the idea consists in reducing the energy spent in the transmission of a packet from its source to its destination, while avoiding nodes with low residual energy. The solution we propose, called EOLSR, is based on the link state OLSR routing protocol. We show by simulation that this solution outperforms the solution that selects routes minimizing the end-to-end energy consumption, as well as the solution that builds routes based on node residual energy. We then show how we can improve the benefit of energy efficient routing using cross layering. Informa- tion provided by the MAC layer improves the reactivity of the routing protocol and the robustness of routes. Moreover, taking into account the specificities of some applications like data gathering allows the routing protocol to reduce its overhead by maintaining routes only to the sink nodes. Concerning node activity scheduling, since the sleep state is the least power consuming state, our aim is to schedule node state between sleeping and active to minimize energy consumption while ensuring network and application functionalities. We propose a solution, called SERENA, based on node coloring. The idea is to assign a color to each node, while using a small number of colors and ensuring that two nodes with the same color can transmit without interfering. This color is mapped into a slot in which the node can transmit its messages. Consequently, each node is awake during its slot and the slots granted to its one-hop neighbors. It sleeps the remaining time. We show how this algorithm can adapt to different application requirements: broadcast, immediate acknowledgement of unicast transmissions... The impact of each additional requirement is evaluated by simulation. An originality of this work lies in taking into account real wireless propagation conditions. Color conflicts are then possible. A cross-layering approach with the MAC layer is used to solve these conflicts. We also show how cross-layering with the application layer can improve the coloring per- formance for data gathering applications. This work has been done for the ANR OCARI project whose aim is to design and implement a wireless sensor network for applications in harsh environments such as power plants and war- ships. The network layer including SERENA and EOLSR has been specified and is now under implementation.