Bell-X, An Opportunistic Time Synchronization Mechanism for Scheduled Wireless Sensor Networks

[EN] The Industrial Internet of Things (IIoT) is having an ever greater impact on industrial processes and the manufacturing sector, due the capabilities of massive data collection and interoperability with plant processes, key elements that are focused on the implementation of Industry 4.0. Wireless Sensor Networks (WSN) are one of the enabling technologies of the IIoT, due its self-configuration and self-repair capabilities to deploy ad-hoc networks. High levels of robustness and reliability, which are necessary in industrial environments, can be achieved by using the Time-Slotted Channel Hopping (TSCH) medium access the mechanism of the IEEE 802.15.4e protocol, penalizing other features, such as network connection and formation times, given that a new node does not know, a priori, the scheduling used by the network. This article proposes a new beacon advertising approach for a fast synchronization for networks under the TSCH-Medium Access Control (MAC) layer and Routing Protocol for Low-Power and Lossy Networks (RPL). This new method makes it possible to speed up the connection times of new nodes in an opportunistic way, while reducing the consumption and advertising traffic generated by the network.This work has been supported by the SCOTT project (Secure COnnected Trustable Things) (www.scottproject.eu), which has received funding from the Electronic Component Systems for European Leadership Joint Undertaking under grant agreement No. 737422. This Joint Undertaking receives support from the European Union's Horizon 2020 research and innovation programme, and from Austria, Spain, Finland, Ireland, Sweden, Germany, Poland, Portugal, Netherlands, Belgium and Norway. It has also been funded by Generalitat Valenciana through the "Instituto Valenciano de Competitividad Empresarial - IVACE", and by the MCyU (Spanish Ministry of Science and Universities) under the project ATLAS (PGC2018-094151-B-I00), which is partially funded by AEI, FEDER and EU.Vera-Pérez, J.; Todoli Ferrandis, D.; Silvestre-Blanes, J.; Sempere Paya, VM. (2019). Bell-X, An Opportunistic Time Synchronization Mechanism for Scheduled Wireless Sensor Networks. Sensors. 19(19):1-22. https://doi.org/10.3390/s19194128S1221919Vitturi, S., Zunino, C., & Sauter, T. (2019). Industrial Communication Systems and Their Future Challenges: Next-Generation Ethernet, IIoT, and 5G. Proceedings of the IEEE, 107(6), 944-961. doi:10.1109/jproc.2019.2913443Candell, R., Kashef, M., Liu, Y., Lee, K. B., & Foufou, S. (2018). Industrial Wireless Systems Guidelines: Practical Considerations and Deployment Life Cycle. IEEE Industrial Electronics Magazine, 12(4), 6-17. doi:10.1109/mie.2018.2873820Brandt, A., Hui, J., Kelsey, R., Levis, P., Pister, K., … Struik, R. (2012). RPL: IPv6 Routing Protocol for Low-Power and Lossy Networks. doi:10.17487/rfc6550Vera-Pérez, J., Todolí-Ferrandis, D., Santonja-Climent, S., Silvestre-Blanes, J., & Sempere-Payá, V. (2018). A Joining Procedure and Synchronization for TSCH-RPL Wireless Sensor Networks. Sensors, 18(10), 3556. doi:10.3390/s18103556Pister, K., & Watteyne, T. (2017). Minimal IPv6 over the TSCH Mode of IEEE 802.15.4e (6TiSCH) Configuration. doi:10.17487/rfc8180Levis, P., Clausen, T., Hui, J., Gnawali, O., & Ko, J. (2011). The Trickle Algorithm. doi:10.17487/rfc6206Contiki: The Open Source OS for the Internet of Things: Official Website www.contiki-os.orgStanislowski, D., Vilajosana, X., Wang, Q., Watteyne, T., & Pister, K. S. J. (2014). Adaptive Synchronization in IEEE802.15.4e Networks. IEEE Transactions on Industrial Informatics, 10(1), 795-802. doi:10.1109/tii.2013.2255062Chang, T., Watteyne, T., Pister, K., & Wang, Q. (2015). Adaptive synchronization in multi-hop TSCH networks. Computer Networks, 76, 165-176. doi:10.1016/j.comnet.2014.11.003Palattella, M., & Grieco, L. (2015). Using IEEE 802.15.4e Time-Slotted Channel Hopping (TSCH) in the Internet of Things (IoT): Problem Statement. doi:10.17487/rfc7554Vogli, E., Ribezzo, G., Grieco, L. A., & Boggia, G. (2018). Fast network joining algorithms in industrial IEEE 802.15.4 deployments. Ad Hoc Networks, 69, 65-75. doi:10.1016/j.adhoc.2017.10.013Duy, T. P., Dinh, T., & Kim, Y. (2016). A rapid joining scheme based on fuzzy logic for highly dynamic IEEE 802.15.4e time-slotted channel hopping networks. International Journal of Distributed Sensor Networks, 12(8), 155014771665942. doi:10.1177/1550147716659424Khoufi, I., Minet, P., & Rmili, B. (2019). Beacon advertising in an IEEE 802.15.4e TSCH network for space launch vehicles. Acta Astronautica, 158, 76-88. doi:10.1016/j.actaastro.2018.07.021Karalis, A., Zorbas, D., & Douligeris, C. (2019). Collision-Free Advertisement Scheduling for IEEE 802.15.4-TSCH Networks. Sensors, 19(8), 1789. doi:10.3390/s19081789Vallati, C., Brienza, S., Anastasi, G., & Das, S. K. (2019). Improving Network Formation in 6TiSCH Networks. IEEE Transactions on Mobile Computing, 18(1), 98-110. doi:10.1109/tmc.2018.2828835De Guglielmo, D., Anastasi, G., & Seghetti, A. (2014). From IEEE 802.15.4 to IEEE 802.15.4e: A Step Towards the Internet of Things. Advances onto the Internet of Things, 135-152. doi:10.1007/978-3-319-03992-3_1

TSCH and RPL Joining Time Model for Industrial Wireless Sensor Networks

[EN] Wireless sensor networks (WSNs) play a key role in the ecosystem of the Industrial Internet of Things (IIoT) and the definition of today's Industry 4.0. These WSNs have the ability to sensor large amounts of data, thanks to their easy scalability. WSNs allow the deployment of a large number of self-configuring nodes and the ability to automatically reorganize in case of any change in the topology. This huge sensorization capacity, together with its interoperability with IP-based networks, allows the systems of Industry 4.0 to be equipped with a powerful tool with which to digitalize a huge amount of variables in the different industrial processes. The IEEE 802.15.4e standard, together with the access mechanism to the Time Slotted Channel Hopping medium (TSCH) and the dynamic Routing Protocol for Low-Power and Lossy Networks (RPL), allow deployment of networks with the high levels of robustness and reliability necessary in industrial scenarios. However, these configurations have some disadvantages in the deployment and synchronization phases of the networks, since the time it takes to synchronize the nodes is penalized compared to other solutions in which access to the medium is done randomly and without channel hopping. This article proposes an analytical model to characterize the behavior of this type of network, based on TSCH and RPL during the phases of deployment along with synchronization and connection to the RPL network. Through this model, validated by simulation and real tests, it is possible to parameterize different configurations of a WSN network based on TSCH and RPL.This work has been supported by the MCyU (Spanish Ministry of Science and Universities) under the project ATLAS (PGC2018-094151-B-I00), which is partially funded by AEI, FEDER and EU.Vera-Pérez, J.; Silvestre-Blanes, J.; Sempere Paya, VM. (2021). TSCH and RPL Joining Time Model for Industrial Wireless Sensor Networks. Sensors. 21(11):1-17. https://doi.org/10.3390/s21113904117211

Hybrid schedule management in 6TiSCH networks : the coexistence of determinism and flexibility

With the emergence of the Internet of Things (IoT), Industry 4.0 and Cyber-Physical System (CPS) concepts, there is a tremendous change ongoing in industrial applications that is imposing increasingly diverse and demanding network dynamics and requirements with a wider and more fine-grained scale. The purpose of this article is to investigate how a Hybrid Schedule Management in 6TiSCH architecture can be used to achieve the coexistence of applications with heavily diverse networking requirements. We study the fundamental functionalities and also describe network scenarios where such a hybrid scheduling approach can be used. In addition, we present the details about the design and implementation of the first 6TiSCH Centralized Scheduling Framework based on CoMI. We also provide theoretical and experimental analysis where we study the cost of schedule management operations and illustrate the operation of the CoMI-based 6TiSCH Schedule Management

The Contiki-NG open source operating system for next generation IoT devices

Contiki-NG (Next Generation) is an open source, cross-platform operating system for severely constrained wireless embedded devices. It focuses on dependable (reliable and secure) low-power communications and standardised protocols, such as 6LoWPAN, IPv6, 6TiSCH, RPL, and CoAP. Its primary aims are to (i) facilitate rapid prototyping and evaluation of Internet of Things research ideas, (ii) reduce time-to-market for Internet of Things applications, and (iii) provide an easy-to-use platform for teaching embedded systems-related courses in higher education. Contiki-NG started as a fork of the Contiki OS and retains many of its original features. In this paper, we discuss the motivation behind the creation of Contiki-NG, present the most recent version (v4.7), and highlight the impact of Contiki-NG through specific examples

Integrating secure mobile P2P systems and Wireless Sensor Networks

Aquesta tesi tracta de les diferents limitacions trobades a WSN per a habilitar-ne el desplegament en nous escenaris i facilitar la difusió de la informació obtinguda. A un nivell baix, ens centrem en el consum d'energia, mentre que, a un nivell més alt, ens focalitzem en la difusió i la seguretat de la informació. Reduïm el consum d'una mote individual en xarxes amb patrons de trànsit dinàmic mitjançant la definició d'una funció de planificació basada en el conegut controlador PID i allarguem la vida d'una WSN globalment distribuint equitativament el consum energètic de totes les motes, disminuint el nombre d'intervencions necessàries per a canviar bateries i el cost associat. Per tal d'afavorir la difusió de la informació provinent d'una WSN, hem proposat jxSensor, una capa d'integració entre les WSN i el conegut sistema P2P JXTA. Com que tractem informació sensible, hem proposat una capa d'anonimat a JXTA i un mecanisme d'autenticació lleuger per a la seva versió mòbil.Esta tesis trata las diferentes limitaciones encontradas en WSN para habilitar su despliegue en nuevos escenarios, así como facilitar la diseminación de la información obtenida. A bajo nivel, nos centramos en el consumo de energía, mientras que, a un nivel más alto, nos focalizamos en la diseminación y seguridad de la información. Reducimos el consumo de una mota individual en redes con patrones de tráfico dinámico mediante la definición de una función de planificación basada en el conocido controlador PID y alargamos la vida de una WSN globalmente distribuyendo equitativamente el consumo energético de todas las motas, disminuyendo el número de intervenciones requeridas para cambiar baterías y su coste asociado. Para favorecer la diseminación de la información procedente de una WSN hemos propuesto jxSensor, una capa de integración entre las WSN y el conocido sistema P2P JXTA. Como estamos tratando con información sensible, hemos propuesto una capa de anonimato en JXTA y un mecanismo de autenticación ligero para su versión móvil.This thesis addresses different limitations found in WSNs in order to enable their deployment in new scenarios as well as to make it easier to disseminate the gathered information. At a lower level, we concentrate on energy consumption while, at a higher level, we focus on the dissemination and security of information. The consumption of an individual mote in networks with dynamic traffic patterns is reduced by defining a scheduling function based on the well-known PID controller. Additionally, the life of a WSN is extended by equally distributing the consumption of all the motes, which reduces the number of interventions required to replace batteries as well as the associated cost. To help the dissemination of information coming from a WSN we have proposed jxSensor, which is an integration layer between WSNs and the well-known JXTA P2P system. As we are dealing with sensitive information, we have proposed an anonymity layer in JXTA and a light authentication method in its mobile version