Demo: Simulating a 6TiSCH Network using Connectivity Traces from Testbeds

International audienceThe 6TiSCH simulator is an existing Python-based simulation tool that captures the full behavior of 6TiSCH, the Industrial IoT protocol stack standardized by the IETF. The existing 6TiSCH simulator uses a radio propagation model. In this demo, we present an extension to the 6TiSCH simulator which allows a simulation to be run against connectivity traces previously gathered on testbeds and real-world deployments. We demonstrate four elements. First, Mercator, the OpenWSN-based tool we developed to collect connectivity traces from different testbeds. Second, K7, the generic format we defined for these connectivity traces. Third, the set of 17 connectivity traces we gathered from testbeds and real-world deployments, and which are publicly available. Fourth, the extension of the 6TiSCH simulator which enables it to replay K7 connectivity traces rather than using a propagation model. Using connectivity traces for simulation is a way to increase the confidence the result are representative of a real-world deployment. Furthermore, it allows better repeatability than re-running an experiment on a testbed where the connectivity necessarily changes over time

IPV6 for IOT

Svakodnevnim povećanjem broja uređaja koji se povezuju na Internet te na taj način komuniciraju, prikupljaju i razmijenjuju podatke, dolazi do potrebe za sve većim brojem IP adresa. Zbog ograničenog broja adresa koje nudi IPv4 protokol, IPv6 po tom pitanju nudi rješenje za Internet stvari. IPv6 Internet stvarima osim povećanog broja IP adresa nudi i razne druge pogodnosti i mogućnosti kao što su veća sigurnost, mobilnost. Internet stvari zahtjevaju arhitekture softvera koje su u mogućnosti nositi se sa velikom količinom podataka i zahtjevima. IoT uređaji zahtjevaju komunikaciju niske potrošnje te su zbog toga definirani protokoli na različitim slojevima LLN stoga, uključujući 6LoWPAN sloj adaptacije, RPL protokol usmjeravanja te CoAP protokol web prijenosa. U samo godinu dana, broj IoT uređaja povezanih na internet porastao je sa 5 milijuna na nekoliko milijardi. Mnogo se novaca ulaže u razvoj takvih uređaja i njihov će broj zasigurno i dalje rast

IPV6 for IOT

Svakodnevnim povećanjem broja uređaja koji se povezuju na Internet te na taj način komuniciraju, prikupljaju i razmijenjuju podatke, dolazi do potrebe za sve većim brojem IP adresa. Zbog ograničenog broja adresa koje nudi IPv4 protokol, IPv6 po tom pitanju nudi rješenje za Internet stvari. IPv6 Internet stvarima osim povećanog broja IP adresa nudi i razne druge pogodnosti i mogućnosti kao što su veća sigurnost, mobilnost. Internet stvari zahtjevaju arhitekture softvera koje su u mogućnosti nositi se sa velikom količinom podataka i zahtjevima. IoT uređaji zahtjevaju komunikaciju niske potrošnje te su zbog toga definirani protokoli na različitim slojevima LLN stoga, uključujući 6LoWPAN sloj adaptacije, RPL protokol usmjeravanja te CoAP protokol web prijenosa. U samo godinu dana, broj IoT uređaja povezanih na internet porastao je sa 5 milijuna na nekoliko milijardi. Mnogo se novaca ulaže u razvoj takvih uređaja i njihov će broj zasigurno i dalje rast

A Load Balancing Algorithm for Resource Allocation in IEEE 802.15.4e Networks

The recently created IETF 6TiSCH working group combines the high reliability and low-energy consumption of IEEE 802.15.4e Time Slotted Channel Hopping with IPv6 for industrial Internet of Things. We propose a distributed link scheduling algorithm, called Local Voting, for 6TiSCH networks that adapts the schedule to the network conditions. The algorithm tries to equalize the link load (defined as the ratio of the queue length over the number of allocated cells) through cell reallocation. Local Voting calculates the number of cells to be added or released by the 6TiSCH Operation Sublayer (6top). Compared to a representative algorithm from the literature, Local Voting provides simultaneously high reliability and low end-to-end latency while consuming significantly less energy. Its performance has been examined and compared to On-the-fly algorithm in 6TiSCH simulator by modeling an industrial environment with 50 sensors

Survey de Protocolos Normalizados por IETF/IRTF para Aplicaciones de Internet of Things (IoT)

Por lo general, el término Internet de las Cosas se refiere a escenarios en los que la conectividad de red y la capacidad de cómputo se extienden a objetos y sensores de reducidas dimensiones y escaso poder de cálculo, permitiendo que estos dispositivos generen, intercambien y consuman datos con una mínima intervención humana. En la Internet tradicional, la interoperabilidad es el valor esencial; o sea el primer requisito de una buena conectividad a Internet es que los sistemas “conectados” deben poder “hablar el mismo idioma” en cuanto a protocolos y codificaciones. La interoperabilidad eficaz y bien definida, puede fomentar la innovación y ofrecer eficiencias a quienes fabrican dispositivos, aumentando así el valor económico total del mercado. IoT implica vincular dispositivos, que en muchos casos nunca se han conectado antes, o al menos no en otra cosa que no sea una red cerrada y especializada. En un entorno totalmente interoperable, cualquier dispositivo de la IoT se podría conectar a cualquier otro dispositivo o sistema e intercambiar información si así lo desean. La interoperabilidad, los estándares, los protocolos y las convenciones son temas fundamentales en el desarrollo y la adopción temprano de los dispositivos de la IoT. También implica administrar esos objetos y desarrollar aplicaciones para que hagan cosas juntas que nunca podrían hacer solos. Entonces, los productos de diferentes proveedores eventualmente tendrán que hablar el mismo idioma, en algún nivel. El Internet Engineering Task Force (IETF) es una de las más importantes entidades de estandarización de los protocolos de Internet. Como tal y desde hace unos años, ha venido generando varios protocolos para IoT. En esta comunicación se revisan estos nuevos potocolos como así también los grupos de trabajo donde fueron creados.Sociedad Argentina de Informática e Investigación Operativ

Survey de Protocolos Normalizados por IETF/IRTF para Aplicaciones de Internet of Things (IoT)

Por lo general, el término Internet de las Cosas se refiere a escenarios en los que la conectividad de red y la capacidad de cómputo se extienden a objetos y sensores de reducidas dimensiones y escaso poder de cálculo, permitiendo que estos dispositivos generen, intercambien y consuman datos con una mínima intervención humana. En la Internet tradicional, la interoperabilidad es el valor esencial; o sea el primer requisito de una buena conectividad a Internet es que los sistemas “conectados” deben poder “hablar el mismo idioma” en cuanto a protocolos y codificaciones. La interoperabilidad eficaz y bien definida, puede fomentar la innovación y ofrecer eficiencias a quienes fabrican dispositivos, aumentando así el valor económico total del mercado. IoT implica vincular dispositivos, que en muchos casos nunca se han conectado antes, o al menos no en otra cosa que no sea una red cerrada y especializada. En un entorno totalmente interoperable, cualquier dispositivo de la IoT se podría conectar a cualquier otro dispositivo o sistema e intercambiar información si así lo desean. La interoperabilidad, los estándares, los protocolos y las convenciones son temas fundamentales en el desarrollo y la adopción temprano de los dispositivos de la IoT. También implica administrar esos objetos y desarrollar aplicaciones para que hagan cosas juntas que nunca podrían hacer solos. Entonces, los productos de diferentes proveedores eventualmente tendrán que hablar el mismo idioma, en algún nivel. El Internet Engineering Task Force (IETF) es una de las más importantes entidades de estandarización de los protocolos de Internet. Como tal y desde hace unos años, ha venido generando varios protocolos para IoT. En esta comunicación se revisan estos nuevos potocolos como así también los grupos de trabajo donde fueron creados.Sociedad Argentina de Informática e Investigación Operativ

Guard time optimisation and adaptation for energy efficient multi-hop TSCH networks

International audienceIn the IEEE 802.15.4-2015 standard, Time Slotted Channel Hopping (TSCH) aims to guarantee high-level network reliability by keeping nodes time-synchronised. In order to ensure successful communication between a sender and a receiver, the latter starts listening shortly before the expected time of a MAC layer frame's arrival. The offset between the time a node starts listening and the estimated time of frame arrival is called guard time and it aims to reduce the probability of missed frames due to clock drift. In this paper, we investigate the impact of the guard time on network performance. We identify that, when using the 6tisch minimal schedule, the most significant cause of energy consumption is idle listening during guard time. Therefore, we first perform mathematical modelling on a TSCH link to identify the guard time that maximises the energy-efficiency of the TSCH network in single hop topology. We then continue in multi-hop network, where we empirically adapt the guard time locally at each node depending its distance, in terms of hops, from the sink. Our performance evaluation results, conducted using the Contiki OS, demonstrate that the proposed decentralised guard time adaptation can reduce the energy consumption by up to 40%, without compromising network reliability

Towards efficient coexistence of IEEE 802.15.4e TSCH and IEEE 802.11

A major challenge in wide deployment of smart wireless devices, using different technologies and sharing the same 2.4 GHz spectrum, is to achieve coexistence across multiple technologies. The IEEE~802.11 (WLAN) and the IEEE 802.15.4e TSCH (WSN) where designed with different goals in mind and both play important roles for respective applications. However, they cause mutual interference and degraded performance while operating in the same space. To improve this situation we propose an approach to enable a cooperative control which type of network is transmitting at given time, frequency and place. We recognize that TSCH based sensor network is expected to occupy only small share of time, and that the nodes are by design tightly synchronized. We develop mechanism enabling over-the-air synchronization of the Wi-Fi network to the TSCH based sensor network. Finally, we show that Wi-Fi network can avoid transmitting in the "collision periods". We provide full design and show prototype implementation based on the Commercial off-the-shelf (COTS) devices. Our solution does not require changes in any of the standards.Comment: 8 page

Determinism Through Path Diversity: Why Packet Replication Makes Sense

International audienceIndustrial low-power wireless mesh standards, such as IEEE802.15.4-TSCH, WirelessHART and ISA100.10a, offer wire-like end-to-end reliability and a decade of battery lifetime. These technologies have become de-facto standards, used in the most demanding applications such as industrial process monitoring. In this paper, we explore what it takes to go from industrial process monitoring to industrial process control. The difference is that, in the latter case, the network needs to provide low and predicable latency, and deterministic operation. We explore the overall usefulness of packet replication, in which a source node sends multiple copies of a packet on disjoint multihop paths. We show, through extensive simulation, that packet replication allows for a reduction of end-to-end latency by 40%. In addition, packet replication significantly improves the network reliability through path diversity. This work is directly in line with standardization activities at the IETF 6TiSCH and DetNet working groups, to which it is being contributed