DETN: delay-efficient tolerant network for internet of planet

The explosion of the internet has resulted in various emerging technologies, as for example the Internet of Things (IoT). IoT is an intelligent technology and service connecting objects in the Internet. IoT facilitates the exchange of information between people and devices that communicate with each other. Beyond IoT, we are now studying a new paradigm called Internet of Planets (IoP), in which planets in a solar system communicate with each other using the Internet. This paper presents our research in the internet communications between planets, detailing benefits, limitations and directions for future work. We propose a time (delay) information-based Delay Efficient Tolerant Networking (DETN) routing scheme for efficient data transmission among mobile nodes. The results of the proposed DTN routing algorithm using NS-3 simulation tools indicate satisfactory levels of routing performance in comparison with existing DTN algorithms.N/

Multi-Robot Systems: Challenges, Trends and Applications

This book is a printed edition of the Special Issue entitled “Multi-Robot Systems: Challenges, Trends, and Applications” that was published in Applied Sciences. This Special Issue collected seventeen high-quality papers that discuss the main challenges of multi-robot systems, present the trends to address these issues, and report various relevant applications. Some of the topics addressed by these papers are robot swarms, mission planning, robot teaming, machine learning, immersive technologies, search and rescue, and social robotics

NeBula: TEAM CoSTAR’s robotic autonomy solution that won phase II of DARPA subterranean challenge

This paper presents and discusses algorithms, hardware, and software architecture developed by the TEAM CoSTAR (Collaborative SubTerranean Autonomous Robots), competing in the DARPA Subterranean Challenge. Specifically, it presents the techniques utilized within the Tunnel (2019) and Urban (2020) competitions, where CoSTAR achieved second and first place, respectively. We also discuss CoSTAR’s demonstrations in Martian-analog surface and subsurface (lava tubes) exploration. The paper introduces our autonomy solution, referred to as NeBula (Networked Belief-aware Perceptual Autonomy). NeBula is an uncertainty-aware framework that aims at enabling resilient and modular autonomy solutions by performing reasoning and decision making in the belief space (space of probability distributions over the robot and world states). We discuss various components of the NeBula framework, including (i) geometric and semantic environment mapping, (ii) a multi-modal positioning system, (iii) traversability analysis and local planning, (iv) global motion planning and exploration behavior, (v) risk-aware mission planning, (vi) networking and decentralized reasoning, and (vii) learning-enabled adaptation. We discuss the performance of NeBula on several robot types (e.g., wheeled, legged, flying), in various environments. We discuss the specific results and lessons learned from fielding this solution in the challenging courses of the DARPA Subterranean Challenge competition.Peer ReviewedAgha, A., Otsu, K., Morrell, B., Fan, D. D., Thakker, R., Santamaria-Navarro, A., Kim, S.-K., Bouman, A., Lei, X., Edlund, J., Ginting, M. F., Ebadi, K., Anderson, M., Pailevanian, T., Terry, E., Wolf, M., Tagliabue, A., Vaquero, T. S., Palieri, M., Tepsuporn, S., Chang, Y., Kalantari, A., Chavez, F., Lopez, B., Funabiki, N., Miles, G., Touma, T., Buscicchio, A., Tordesillas, J., Alatur, N., Nash, J., Walsh, W., Jung, S., Lee, H., Kanellakis, C., Mayo, J., Harper, S., Kaufmann, M., Dixit, A., Correa, G. J., Lee, C., Gao, J., Merewether, G., Maldonado-Contreras, J., Salhotra, G., Da Silva, M. S., Ramtoula, B., Fakoorian, S., Hatteland, A., Kim, T., Bartlett, T., Stephens, A., Kim, L., Bergh, C., Heiden, E., Lew, T., Cauligi, A., Heywood, T., Kramer, A., Leopold, H. A., Melikyan, H., Choi, H. C., Daftry, S., Toupet, O., Wee, I., Thakur, A., Feras, M., Beltrame, G., Nikolakopoulos, G., Shim, D., Carlone, L., & Burdick, JPostprint (published version

Wake-up radio systems : design, development, performance evaluation and comparison to conventional medium access control protocols for wireless sensor networks

During the recent years, the research related to Wake-up Radio (WuR) systems has gained noticeable interest. In WuR systems, a node initiating a communication first sends a Wake-up Call (WuC) by means of its Wake-up Transmitter (WuTx), to the Wake-up Receiver (WuRx) of a remote node to activate it in an on-demand manner. Until the reception of the WuC, the node's MCU and main data transceiver are in sleep mode. Hence, WuR drastically reduce the power required by wireless nodes. This thesis provides a complete analysis of several WuR designs vs. conventional MAC protocols for Wireless Sensor Networks (WSN). The research is performed in an incremental fashion and includes hardware, softwar and simulation topics. WuR systems enable energy savings in plenty of different applications, e.g., retrieving information from environmental pollution sensors placed in a city by a mobile collector node, or activating a sleeping wireless AP. They are easy to program in and provide implicit synchronization. However, achieving a good WuRx design may become a challenge because power amplifiers cannot be used for the sake of energy. The system proposed in chapter 2 is a successful WuR system prototype. The so-called SµA-WuRx is less complex than commercial WuR systems, it is cheaper from the monetary point of view, requires several times less energy and allows for up to 15 meters of communication, an adequate value for WuR systems. However, the system can be improved by including several desirable features, such as longer operational ranges and/or addressing mechanisms. The so-called Time-Knocking (TicK) addressing strategy, analyzed in chapter 3, enables energy efficient node addressing by varying the time between WuCs received by a MCU. TicK allows for variable length addresses and multicast. A WuR system may not fit any possible application. Thus, while the SµA-WuRx and TicK efficiently solved many of the requirements of single-hop and data-collector applications, they lack of flexibility. Instead, SCM-WuR systems in chapter 4 feature an outstanding trade-off between hardware complexity, current consumption and operational range, and even enable multi-hop wake-up for long remote sensor measure collection. To contextualize the WuR systems developed, chapter 5 provides an overview of the most important WuR systems as of 2014. Developing a MAC protocol which performs acceptably in a wide range of diverse applications is a very difficult task. Comparatively, SCM-WuR systems perform properly in all the use cases (single and multi-hop) presented in chapter 6. Bluetooth Low Energy, or BLE, appears as a duty-cycled MAC protocol mainly targeting single-hop applications. Because of its clearly defined use cases and its integration with its upper application layers, BLE appears as an extremely energy-efficient protocol that cannot be easily replaced by WuR. Because of all these aspects, the performance of BLE is analyzed in chapter 7. Finally, chapter 8 tries to solve one of the issues affecting WuR systems, that is, the need for extra hardware. While this issue seems difficult to solve for WuRx, the chapter provides ideas to use IEEE 802.11-enabled devices as WuTx.Durant els últims anys, la investigació relativa als sistemes de Ràdios de Wake-up (de l'anglès Wake-up Radio, WuR) ha experimentat un interès notable. En aquests sistemes, un node inicia la comunicació inal.làmbrica transmetent una Wake-up Call (WuC), per mitjà del seu transmissor de Wake-up (WuTx), dirigida al receptor de Wake-up (WuRx) del node remot. Aquesta WuC activa el node remot, el microcontrolador (MCU) i la ràdio principals del qual han pogut romandre en mode "sleep" fins el moment. Així doncs, els sistemes WuR permeten un estalvi dràstic de l'energia requerida pels nodes sense fils. Aquesta tesi proposa diferents sistemes WuR i els compara amb protocols MAC existents per a xarxes de sensors sense fils (Wireless Sensor Networks, WSN). La investigació es realitza de forma progressiva i inclou hardware, software i simulació. Els sistemes WuR permeten un estalvi energètic notable en moltes aplicacions: recol¿lecció d'informació ambiental, activació remota de punts d'accés wi-fi, etc. Són fàcils de programar en software i comporten una sincronització implícita entre nodes. Malauradament, un consum energètic mínim impossibilita l'ús d'amplificadors de potència, i dissenyar-los esdevé un repte. El sistema presentat en el capítol 2 és un prototip exitós de sistema WuR. De nom SµA-WuR, és més senzill que alternatives comercials, és més econòmic, requereix menys energia i permet distàncies de comunicació WuR majors, de fins a 15 metres. L'estratègia d'adreçament Time-KnocKing, presentada en el capítol 3, permet dotar l'anterior SµA-WuR d'una forma d'especificar el node adreçat, permetent estalvi energètic a nivell de xarxa. TicK opera codificant el temps entre diferents WuC. Depenent del temps entre intervals, es desperten el/s node/s desitjats d'una forma extremadament eficient. Tot i els seus beneficis, hi ha aplicacions no implementables amb el sistema SµA-WuR. Per a aquest motiu, en el capítol 4 es presenta el sistema SCM-WuR, que ofereix un rang d'operació de 40 a 100 metres a canvi d'una mínima complexitat hardware afegida. SCM-WuR cobreix el ventall d'aplicacions del sistema SµA-WuRx, i també les que requereixen multi-hop a nivell WuR. El capítol 5 de la tesi compara els dos sistemes WuR anteriors vers les propostes més importants fins el 2014. El capítol 6 inclou un framework de simulació complet amb les bases per a substituir els sistemes basats en duty-cycling a WuR. Degut a que desenvolupar un protocol MAC que operi acceptablement bé en multitud d'aplicacions esdevé una tasca pràcticament impossible, els sistemes WuR presentats amb anterioritat i modelats en aquest capítol representen una solució versàtil, interessant i molt més eficient des del punt de vista energètic. Bluetooth Low Energy, o Smart, o BLE, representa un cas d'aplicació específica on, degut a la gran integració a nivell d'aplicació, la substitució per sistemes de WuR esdevé difícil Per a aquesta raó, i degut a que es tracta d'un protocol MAC extremadament eficient energèticament, aquesta tesi conté una caracterització completa de BLE en el capítol 7. Finalment, el capítol 8 soluciona un dels inconvenients del sistemes WuR, el disseny de WuTx específics, presentant una estratègia per a transformar qualsevol dispositiu IEEE 802.11 en WuTx