Comunicaciones inalámbricas subacuáticas a 2,4 GHz para la transmisión de datos con altas tasas de transferencia

Underwater communication networks have become an important field of research for many research groups in the recent years. These types of networks are envisioned to enable applications for oceanographic data collection, ocean sampling, environmental and pollution monitoring, in other. In order to communicate us through the underwater networks, we can use acoustic links, links based on electromagnetic waves and optical signals. Currently, the applications are based in acoustic systems because the sound waves are better adapted to the aquatic environment, although the characteristics of these waves have important limitations. The main problem when using low frequencies is the lack of bandwidth to transmit high data rate. Sometimes wireless sensors must be placed quite close in order to obtain accurate measures from the water, so higher frequency bands could be used in special cases. In this Project of final grade, we measure the maximum coverage distance of underwater wireless sensors when they are placed at about 15 cm underneath the water surface, without having wireless coverage from the air side. In order to characterize the behavior of this communication method, we measure, the number of lost packets and round trip time of pings, for transfer rates of 1 Mbps, 2, 5.5 and 11, working with different modulations at different frequencies for different distances. Las redes subacuáticas de comunicación se han convertido, en los últimos años, en un importante campo de investigación para muchos grupos de investigación. Este tipo de redes se prevén que sean utilizadas, para posibilitar el desarrollo de aplicaciones para la recolección de datos oceanográficos, toma de muestras del océano, la monitorización de contaminación ambiental, en otros. Para poder comunicarnos a través de las redes subacuáticas, podemos utilizar, enlaces acústicos, enlaces, basados en ondas electromagnéticas y señales ópticas. Actualmente, las aplicaciones se basan en sistemas acústicos debido a que las ondas acústicas se adaptan mejor al medio acuático, aunque por las características de este tipo de ondas, presenta limitaciones importantes. El principal problema al utilizar las frecuencias bajas es la falta de ancho de banda para transmitir datos a alta velocidad. Pero, existen casos, donde los sensores inalámbricos ser colocado muy cerca con el fin de obtener medidas exactas del agua, por lo que se podría utilizar las bandas de frecuencia más alta, en casos especiales. En este trabajo final de grado, se mide la distancia de cobertura máxima de sensores inalámbricos subacuáticos cuando se colocan a unos 15 cm por debajo de la superficie del agua, sin la necesidad de tener cobertura inalámbrica desde el lado del aire. Caracterizaremos en comportamiento de este método de comunicación, midiendo, número de paquetes perdidos y el tiempo de ida y vuelta de los pings, instantáneos y medios), para tasas de transferencia de 1 Mbps, 2, 5,5 y 11, que trabajan con distintas modulaciones, en diferentes frecuencias para diferentes distancias.Sendra Compte, S. (2011). Comunicaciones inalámbricas subacuáticas a 2,4 GHz para la transmisión de datos con altas tasas de transferencia. Universitat Politècnica de València. http://hdl.handle.net/10251/14605Archivo delegad

Blended Learning in a Postgraduate ICT course

[EN] University subjects trend to be very theoretical, while enterprise generally demands graduate students with high practical skills. The major concern in remote teaching and online learning is the high trend to create a theoretical course. This is usually solved adding remote practices and hands on practices in a real laboratory. In this paper, we present a blended learning training plan carried out during three years with graduate students. First, we will present the course content and the pursued objectives. Then, we will show the learning methods performed to achieve our goals. This paper also analyses the profile of the students included in this course and reviews, in terms of age and gender, how they impact to the class results. The most part of course is conducted through an online learning platform where all students are supervised through tutorials. During the attendance days, students perform collaborative practices with real devices. Finally, we will analyze the student’s opinions and their qualifications during the three years. As results show, the level of acceptance of this kind of teaching innovations depends on the age of the participants and their previous knowledge of these new technologiesSendra Compte, S.; Jimenez, JM.; Parra Boronat, L.; Lloret, J. (2015). Blended Learning in a Postgraduate ICT course. En 1ST INTERNATIONAL CONFERENCE ON HIGHER EDUCATION ADVANCES (HEAD' 15). Editorial Universitat Politècnica de València. 516-525. https://doi.org/10.4995/HEAD15.2015.491OCS51652

Smart Wireless Sensor Network to Detect and Protect Sheep and Goats to Wolf Attacks

The attacks on flocks of goats and sheep are causing great economic losses in some countries. The main causes of these are usually wild animals such as wolves, or thefts of young animals. When an animal feels the presence of people or animals different than the usual ones, it experiences changes in its vital signs. The parameters which are the most altered are the heart rate and body temperature. This paper presents the development of wireless sensor nodes which can monitor vital signs of sheep and goats. These nodes form a network of wireless nodes using IEEE 802.15.4 technology. The network runs a smart algorithm able to detect episodes of collective stress on flocks of goats and sheep caused by any predator attack overnight. When the system detects changes in vital signs of animals, it sends an alarm signal to alert the person in charge of the livestock facility and activates audible and visual alarms able to scare off predators and marauders. Our system can help breeders of goats and sheep to protect their herds avoiding large economic losses that this implies.Sendra Compte, S.; Llario Sempere, F.; Parra Boronat, L.; Lloret, J. (2013). Smart Wireless Sensor Network to Detect and Protect Sheep and Goats to Wolf Attacks. Recent Advances in Communications and Networking Technology. 2(2):91-101. doi:10.2174/22117407112016660012S911012

Study of the Optimum Frequency at 2.4GHz ISM Band for Underwater Wireless Ad Hoc Communications

Underwater communications at low frequencies are characterized by the low data rate. But in some cases wireless sensors must be placed quite close to each other and need high data rates in order to accurately sense an ecosystem that could be contaminated by invasive plants or hazardous waste. Most researchers focus their efforts on increasing the data transfer rates for low frequencies, but, due to the wave features, this is very complicated. For this reason, we propose the use of high frequency band communications for these special cases. In this paper we measure the optimum working frequency for an underwater communication in the 2.4 GHz range. We measure the number of lost packets and the average round trip time value for a point-to-point link for different distances. These measures will be performed by varying the data rate, the type of modulation and the working frequency. We will show that we are able to transmit higher data transfer rates, by using higher frequencies, than the using acoustic waves. © 2012 Springer-Verlag.This work has been partially supported by the "Ministerio de Ciencia e Innovación”, through the “Plan Nacional de I+D+i 2008-2011” in the “Subprograma de Proyectos de Investigación Fundamental”, project TEC2011-27516, and by the Polytechnic University of Valencia, though the PAID-15-11 multidisciplinary projects.Sendra Compte, S.; Lamparero Arroyo, JV.; Lloret, J.; Ardid Ramírez, M. (2012). Study of the Optimum Frequency at 2.4GHz ISM Band for Underwater Wireless Ad Hoc Communications. En Lecture Notes in Computer Science. Springer Verlag (Germany). 260-273. https://doi.org/10.1007/978-3-642-31638-8_20S260273Mohsin, A.H., Bakar, K.A., Adekiigbe, A., Ghafoor, K.Z.: A Survey of Energy-aware Routing protocols in Mobile Ad-hoc Networks: Trends and Challenges. Network Protocols and Algorithms 3(4), 1–17 (2011)Segal, M.: Improving Lifetime of Wireless Sensor Networks. Network Protocols and Algorithms 1(2), 48–60 (2009)Garcia, M., Sendra, S., Atenas, M., Lloret, J.: Underwater Wireless Ad-hoc Networks: a Survey. In: Mobile Ad hoc Networks: Current Status and Future Trends, pp. 379–411. CRC Press (2011)Chakraborty, U., Tewary, T., Chatterjee, R.P.: Exploiting the loss-frequency relationship using RF communication in Underwater communication networks. In: Proceedings of 4th International Conference on Computers and Devices for Communication, CODEC 2009, Kolkata, India, December 14-16 (2009)Liebe, H.J., Hufford, G.A., Manabe, T.: A model for the complex permittivity of water at frequencies below 1 THz. International Journal of Infrared and Millimeter Waves 12(7), 659–675 (1991)Somaraju, R., Trumpf, J.: Frequency, Temperature and Salinity Variation of the Permittivity of Seawater. IEEE Transactions on Antennas and Propagation 54(11), 3441–3448 (2006)IEEE Std 802.11, IEEE Standard for Information technology—telecommunications and information exchange between systems—Local and metropolitan area networks—Specific requirements—Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, New York, USA, pp.1–1184 (2007)Chaitanya, D.E., Sridevi, C.V., Rao, G.S.B.: Path loss analysis of underwater communication systems. In: 2011 IEEE Students’ Technology Symposium (TechSym 2011), Kharagpur, India, January 14-16, pp. 65–70 (2011)Sehgal, A., Tumar, I., Schonwalder, J.: Variability of available capacity due to the effects of depth and temperature in the underwater acoustic communication channel. In: OCEANS 2009 – EUROPE, Bremen, Germany, May 11-14, pp. 1–6 (2009)Arnon, S.: Underwater optical wireless communication network. Journal of Optical Engineering 49, 015001 (January 15, 2010), doi: 10.1117/1.3280288Hunt, K.P., Niemeier, J.J., Kruger, A.: RF communications in underwater wireless sensor networks. In: IEEE International Conference on Electro/Information Technology 2010, Normal, Illinois, USA, May 20-22 (2010)Jiang, S., Georgakopoulos, S.: Electromagnetic Wave Propagation into Fresh Water. Journal of Electromagnetic Analysis and Applications 3(07), 261–266 (2011)Sendra, S., Lamparero, J.V., Lloret, J., Ardid, M.: Underwater Communications in Wireless Sensor Networks using WLAN at 2,4Ghz. In: International Workshop on Marine Sensors and Systems (MARSS), Valencia, Spain, October 17-22 (2011)Martin, F., Gorday, P., Adams, J., Leeuwen, H.V.: IEEE 802.15.4 PHY Capabilities (May 2004 ) Doc.: 15-04-0227-04-004A, https://mentor.ieee.org/802.15/file/04/15-04-0227-04-004a-ieee-802-15-4-phy-layer-and-implementation.pptChitode, J.S.: Digital Communications, 1st edn. Technical Publications Pune (2007-2008)Andren, C., Webster, M.: CCK Modulation Delivers 11Mbps for High Rate 802.11 Extension. In: Proceedings of the Wireless Symposium/Portable By Design Conference, San Jose, CA, USA, February 22-26 (Spring 1999)Lloret, J., López, J.J., Ramos, G.: Wireless LAN Deployment in Large Extension Areas: The Case of a University Campus. In: Proceedings of Communication Systems and Networks 2003, Benalmádena, Málaga, Spain, September 8-10 (2003)Ardid, M.: ANTARES: An Underwater Network of Sensors for Neutrino Astronomy and Deep-Sea Research. Ad Hoc & Sensor Wireless Networks 8, 21–34 (2009)Garcia, M., Sendra, S., Lloret, G., Lloret, J.: Monitoring and Control Sensor System for Fish Feeding in Marine Fish Farms. IET Communications 5(12), 1682–1690 (2011); The Institution of Engineering and Technolog

Smart Collaborative Mobile System for Taking Care of Disabled and Elderly People

Official statistics data show that in many countries the population is aging. In addition, there are several illnesses and disabilities that also affect a small sector of the population. In recent years, researchers and medical foundations are working in order to develop systems based on new technologies and enhance the quality of life of them. One of the cheapest ways is to take advantage of the features provided by the smartphones. Nowadays, the development of reduced size smartphones, but with high processing capacity, has increased dramatically. We can take profit of the sensors placed in smartphones in order to monitor disabled and elderly people. In this paper, we propose a smart collaborative system based on the sensors embedded in mobile devices, which permit us to monitor the status of a person based on what is happening in the environment, but comparing and taking decisions based on what is happening to its neighbors. The proposed protocol for the mobile ad hoc network and the smart system algorithm are described in detail. We provide some measurements showing the decisions taken for several common cases and we also show the performance of our proposal when there is a medium size group of disabled or elderly people. Our proposal can also be applied to take care of children in several situations.This work has been partially supported by the Instituto de Telecomunicacoes, Next Generation Networks and Applications Group (NetGNA), Portugal, and by National Funding from the FCT - Fundacao para a Ciencia e a Tecnologia through the PEst-OE/EEI/LA0008/2011 Project.Sendra Compte, S.; Granell Romero, E.; Lloret, J.; Rodrigues, JJPC. (2014). Smart Collaborative Mobile System for Taking Care of Disabled and Elderly People. Mobile Networks and Applications. 19(3):287-302. doi:10.1007/s11036-013-0445-zS287302193Cisco Systems Inc. “Cisco Visual Networking Index: Global Mobile Data Traffic Forecast Update, 2010–2015.” White Paper, February 1, 2011Pereira O, Caldeira J, Rodrigues J (2011) Body sensor network mobile solutions for biofeedback monitoring. J Mob Netw Appl 16(6):713–732Google. Galaxy nexus (2012). Available: http://www.google.com/nexus/E. Commission. “Demography report 2010.” Eurostat, the Statistical Office of the European Union, 2010. At http://ec.europa.eu/social/BlobServlet?docId=6824&langId=enThomas KE, Stevens JA, Sarmiento K, Wald MM (2008) Fall-related traumatic brain injury deaths and hospitalizations among older adults—United States, 2005. J Saf Res 39(3):269–272Fortino G, Giannantonio R, Gravina R, Kuryloski P, Jafari R, (2013) Enabling effective programming and flexible management of efficient body sensor network applications. IEEE Trans Hum Mach Syst 43(1):115–133Bellifemine F, Fortino G, Giannantonio R, Gravina R, Guerrieri A, Sgroi M (2011) SPINE: a domain-specific framework for rapid prototyping of WBSN applications. Softw Pract Exper 41(3):237–265Macias E, Lloret J, Suarez A, Garcia M (2012) Architecture and protocol of a semantic system designed for video tagging with sensor data in mobile devices. Sensors 12(2):2062–2087Sendra S, Granell E, Lloret J, Rodrigues JJPC. Smart Collaborative System Using the Sensors of Mobile Devices for Monitoring Disabled and Elderly People, 3rd IEEE International Workshop on Smart Communications in Network Technologies, Ottawa, Canada, June 11, 2012Lane N, Miluzzo E, Lu H, Peebles D, Choudhury T, Campbell A (2010) A survey of mobile phone sensing. IEEE Commun Mag 48(9):140–150Muldoon C, OHare G, OGrady M (2006) Collaborative agent tuning: Performance enhancement on mobile devices Engineering Societies in the Agents World VI, Lecture Notes in Computer Science, Volume 3963/2006, pp 241–258Turner H, White J, Thompson C, Zienkiewicz K, Campbell S, Schmidt DC (2009) Building Mobile Sensor Networks Using Smartphones and Web Services: Ramifications and Development Challenges, Handbook of Research on Mobility and Computing, Hershey, PA. Available: http://lsrg.cs.wustl.edu/~schmidt/PDF/new-ww-mobile-computing.pdfKansal A, Goraczko M, Zhao F. Building a sensor network of mobile phones, 6th International Conference on Information Processing in Sensor Networks. Cambridge, Massachusetts, USA, April 24–27, 2007 pp 547–548Plaza I, Martín L, Martin S, Medrano C (2011) Mobile applications in an aging society: status and trends. J Syst Softw 84(11):1977–1988Camarinha-Matos L, Afsarmanesh H. 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Proc IEEE 95(1):215–233Arcelus A, Jones MH, Goubran R, Knoefel F (2007) Integration of smart home technologies in a health monitoring system for the elderly, 21st International Conference on Advanced Information Networking and Applications Workshops, vol. 2, pp 820–825Kahmen H, Faig W (1988) Surveying. Walter de Gruyter & Co, New YorkSol LM870 mobile phone features. Available at: http://es.made-in-china.com/co_runrise/product_Dual-SIM-Card-Dual-Standby-GPS-Temperature-UV-Sensor-Pedometer-Sunrise-LM870-Mobile-Phone_hesighyiy.htmlSTLM20 temperature sensor features. Datashhet available at: http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00119601.pdfSendra S, Lloret J, Garcia M, Toledo JF (2011) Power saving and energy optimization techniques for wireless sensor networks. J Commun 6(6):439–459Matlab Website. 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Underwater Wireless Communications in Freshwater at 2.4 GHz

Publisher copyright and source must be acknowledged with citationThere are few equations for underwater communications in the related literature. They show that the speed propagation and absorption coefficient in freshwater are independent of the working frequency of the transmitted signals. However, some studies demonstrate that electromagnetic waves present lower losses when they are working at certain frequencies. In this paper, we perform a set of measurements of electromagnetic (EM) waves at 2.4 GHz in the underwater environment. In our study case, we fix the water conditions and we measure the behavior of EM as a function of several network parameters such as the working frequency, data transfer rates and modulations. Our results will show that higher frequencies do not mean worse network performance. We will also compare our conclusion with some statements extracted from other works.This work has been partially supported by the Ministerio de Ciencia e Innovacion, through the Plan Nacional de I+D+i 2008 - 2011 in the Subprograma de Proyectos de Investigacion Fundamental, project TEC2011 - 27516, and by the Polytechnic University of Valencia, through the PAID-05-12 multidisciplinary projects, Ref: SP20120420. This work has also been partially supported by the Instituto de Telecomunicacoes, Next Generation Networks and Applications Group (NetGNA), Portugal, and by National Funding from the FCT Fundacao para a Ciencia e a Tecnologia through the PEst - OE/EEI/LA0008/2013 Project.Sendra Compte, S.; Lloret, J.; Rodrigues, JJPC.; Aguiar, JM. (2013). Underwater Wireless Communications in Freshwater at 2.4 GHz. IEEE Communications Letters. 17(9):1794-1797. https://doi.org/10.1109/LCOMM.2013.072313.131214S1794179717

Cross-layer Dynamic Admission Control for Cloud-based Multimedia Sensor Networks

Publisher copyright and source must be acknowledged with citation. Must link to publisher version with DOICloud-based communications system is now widely used in many application fields such as medicine, security, environment protection, etc. Its use is being extended to the most demanding services like multimedia delivery. However, there are a lot of constraints when cloud-based sensor networks use the standard IEEE 802.15.3 or IEEE 802.15.4 technologies. This paper proposes a channel characterization scheme combined to a cross-layer admission control in dynamic cloud-based multimedia sensor networks to share the network resources among any two nodes. The analysis shows the behavior of two nodes using different network access technologies and the channel effects for each technology. Moreover, the existence of optimal node arrival rates in order to improve the usage of dynamic admission control when network resources are used is also shown. An extensive simulation study was performed to evaluate and validate the efficiency of the proposed dynamic admission control for cloud-based multimedia sensor networks.This work has been supported in part by Instituto de Telecomunicacoes, Next Generation Networks and Applications Group (NetGNA), Portugal, and in part by National Funding from the Fundacao para a Ciencia e Tecnologia through the Pest-OE/EEI/LA0008/2011.Mendes, LDP.; Rodrigues, JJPC.; Lloret, J.; Sendra Compte, S. (2014). Cross-layer Dynamic Admission Control for Cloud-based Multimedia Sensor Networks. IEEE Systems Journal. 8(1):235-246. doi:10.1109/JSYST.2013.2260653S2352468

Analysis of the academic performance of women in the subject of telematics

[EN] In recent years, different universities with technical degrees are verbalizing the fact that the percentage of women in technical or engineering careers is very low. In many occations, the argument that the practical skills for men and women are different is used as a justifying to explain this inequality. This paper presents a study on the academic performance of students that attent technical courses. Specifically, this study analyzes the subjects of Local Area Networks, Network Integration and Security in Networks and Systems, of the Degree in Interactive Technologies (GTI) taught at the Gandia Campus of the Universitat Politècnica de València (UPV). The study is carried out during several courses for which data is available and it analyzes the percentage of women present in the course, the average grades and the ratio of passes divided by gender. The results show that the academic performance of women in these subjects is better than the marks obtained for their male classmates, so the argument used so far would be invalidated.[ES] En los últimos años, las diferentes univesidades con grados técnicos están verbalizando el hecho de que el porcentaje de mujeres en carreras técnicas o ingenierías es muy bajo. Además, en muchas ocasiones, se usa como argumento justificativo que las habilidades prácticas para hombres y mujeres son distintas, para explicar esta desigualdad. En este articulo se presenta un estudio del rendimiento académico de estudiantes que cursan asignaturas técnicas. En concreto, se analizan las asignaturas de Redes de área local, Integración de redes y Seguridad en redes y sistemas, del Grado en tecnologías interactivas (GTI) que se imparte en el Campus de Gandia de la Universitat Politècnica de València (UPV). El estudio de lleva a cabo durante varios cursos para los que se disponen datos y analiza el porcentaje de mujeres presentes en el curso, las notas medias y el ratio de aprobados divididos por generos. Los resultados muestran que el rendimiento académico de las mujeres en estas asignaturas es mejor que el de sus comañeros varones por lo que el argumento usado hasta ahora quedaría invalidado.Sendra Compte, S.; Ivars Palomares, A.; Lloret Mauri, J.; Jiménez Herranz, JM. (2022). Análisis del rendimiento académico de las mujeres en la materia de telemática. Editorial Universitat Politècnica de València. 647-661. https://doi.org/10.4995/INRED2022.2022.1590464766

Deployment of Efficient Wireless Sensor Nodes for Monitoring in Rural, Indoor and Underwater Environments

Existen muchos trabajos relacionados con el diseño y desarrollo de nodos sensores, donde se presentan gran variedad de aplicaciones. Las redes de sensores inalámbricos pueden facilitarnos y mejorar algunos aspectos de nuestra vida diaria. Es fácil, pensar que si este tipo de dispositivo es tan beneficioso para nosotros y para el entorno donde vivimos, su precio debería ser relativamente barato. Pero podemos comprobar que esto no es así. ¿Por qué estos dispositivos son tan caros? ¿Sería posible desarrollar dispositivos con las mismas capacidades y precios más económicos? ¿Cómo puedo fabricar mis nodos sensores de bajo coste? Esta tesis responde a estas preguntas y muestra algunas de las muchas aplicaciones que los nodos sensores pueden tener. En esta tesis hemos propuesto (e implementado en algunos casos) el desarrollo de nodos sensores para la monitorización del medio, a partir de dispositivos de bajo coste. Para la implementación de un nodo sensor, y en definitiva la red que une a todos estos nodos, es importante conocer el medio donde trabajarán. A lo largo de este documento se presentan las investigaciones llevadas a cabo para el desarrollo de sensores en tres ámbitos de aplicación. En el primero de ellos, se desarrollan dispositivos multisenores para la monitorización del medio. La aplicación de las redes de sensores inalámbricas al medio natural, precisa un estudio de cómo se ven afectadas las señales, en función de la distancia, vegetación, humedad del ambiente, etc. Focalizamos nuestros desarrollos en la verificación de incendios en zonas rurales y en el control de plagas en viñedos donde la detección precoz de estos eventos genera elevados ahorros económicos. También proponemos el desarrollo de una red de collares sensores para ganado domestico, que nos ayudará a reducir y prevenir en muchos casos, los ataques de lobos y hurtos de crías. Por último, dentro de este grupo, presentamos una red permite detectar anomalía de los materiales en edificios y red de sensores que nos permite monitorizar las personas mayores o deficientes, que se mueven junto con un grupo, en una excursión o actividad. El segundo grupo de aplicaciones, hace referencia a la monitorización de espacios en entornos de interior. Para ello hemos analizado el comportamiento de las señales inalámbricas en diferentes escenarios. Los resultados, nos han permitido extraer un nuevo método de diseño de las redes inalámbricas en interiores. Nuestro método, permite definir la mejor ubicación de los dispositivos de red y nodos sensores en interiores con un ahorro en el número de sensores del 15%. Por último, se presenta el estudio sobre las comunicaciones subacuáticas basadas en las ondas electromagnéticas donde analizamos la dependencia de las comunicaciones subacuáticas en agua dulce en función de la frecuencia, temperatura, tasas de transferencia de datos y modulación. Relacionado con el medio subacuático, presentamos 2 propuestas. La primera de ellas hace referencia a la implementación de una red de sensores para granjas marinas que nos permite reducir la cantidad de residuos depositados en el lecho marino y reducir el porcentaje de comida desperdiciada. La segunda propuesta es el desarrollo de dos sensores oceanográficos que nos permitirían controlar la cantidad de comida y heces depositadas en el suelo y controlar la turbidez del agua de manera muy simple y económica Todos estos desarrollos y propuestas, han estado precedidos por un exhaustivo estudio sobre los problemas energéticos que las redes de sensores inalámbricas presentan y las técnicas que pueden emplearse, para prolongar la vida útil de la red y mejorar su estabilidad.There are many works related to the design and development of sensor nodes which present several applications. Wireless sensor networks can facilitate and improve some aspects of our daily lives. It is easy to think that if this type of device is so beneficial to us and to our environment, its price should be relatively cheap. But we can see that this is not true. Why these devices are so expensive? Would it be possible to develop devices with the same capabilities and lower prices? How can I make my low-cost sensor nodes? This dissertation answers these questions and shows some of the many applications that sensor nodes may have. In this dissertation, we propose (and implement in some cases) the development of sensor nodes for environmental monitoring, from low-cost devices. For the implementation of a sensor node and network which joins all these nodes, it is important to know the environment where they will work. Throughout this dissertation, we present the research carried out for the development of sensors in three main application areas. In the first of these areas, we present multisensor devices developed for environmental monitoring. The application of wireless sensor networks to the environment requires a study of how signals are affected depending on the distance, vegetation, ambient humidity, etc. We focus our developments on the fire detection in rural areas and on the control of pests in vineyards where the early detection of these events generates high economic savings. We also propose the development of a sensor network which will help us to reduce and prevent wolves¿ attacks and theft in livestock. Finally, within this group, we present a network to detect material anomalies in building and a sensor network which allows us to monitor the elderly or disabled people who move along with a group on a tour or activity. The second group of applications is related to the monitoring of spaces in indoor environments. For this, we analyze the behavior of wireless signals in different scenarios. These results allowed us to extract a new method for designing wireless networks in indoor environments. Our method allows defining the best location of network devices and sensor nodes indoors saving 15% of the sensors needed. Finally, we present a study on underwater freshwater communications based on electromagnetic waves, where we analyze the dependency of underwater communications as a function of working frequency, temperature, data transfer rates and modulation. Related to underwater environment, we present two proposals. First one refers to the implementation of a sensor network for marine farms which allows us to reduce the amount of waste deposited on the seabed and reduce the percentage of wasted food. The second proposal is the development of two oceanographic sensors which allow us to control the amount of food and feces deposited in seabed and the water turbidity control in a very simple and inexpensive way. All these developments and proposals have been preceded by a comprehensive study on the energy problems in wireless sensor networks. We have also presented several techniques which can be used to prolong the network lifetime and improve its stability.Sendra Compte, S. (2013). Deployment of Efficient Wireless Sensor Nodes for Monitoring in Rural, Indoor and Underwater Environments [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32279TESI