The IETF IPv6 over the TSCH mode of IEEE802.15.4e (6TiSCH) working group has standardized a set of protocols to enable low power industrial-grade IPv6 networks. 6TiSCH proposes a protocol stack rooted in the Time Slotted Channel Hopping (TSCH) mode of the IEEE802.15.4-2015 standard, supports multi-hop topologies with the IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) routing protocol, and is IPv6-ready through 6LoWPAN. 6TiSCH has defined the missing control plane protocols to match link-layer resources to the routing topology and application communication needs. 6TiSCH has also defined a secure light-weight join processes combining link-layer security features (through Counter with CBC-MAC (CCM*)) with a secure joining procedure using the Constrained Application Protocol (CoAP). This tutorial provides a comprehensive overview of the 6TiSCH architecture and protocol suite, including the 6TiSCH Operation Sublayer (6top), the 6top Protocol (6P), and how it uses 6LoWPAN, IP-in-IP encapsulation, and RPL. This document is meant to be used both as a primer, and as a reference. It is tailored to the advanced researcher and engineer implementing and building upon IETF 6TiSCH specifications.

The convergence of operational and information technologies in the industry requires a new generation of IP-compliant communication protocols that can meet the industrial performance requirements while facilitating the integration with novel web-based supervisory control and data acquisition (SCADA) systems. For more than a decade, the industry has relied on time-slotted channel hopping (TSCH) communication technology to meet these performance requirements through standards such as WirelessHART and ISA100.11a. TSCH-based networks have proven to yield over 99.999% end-to-end reliability, supporting flow isolation and QoS management while ensuring over a decade of battery lifetime. However, these technologies were designed to address the factory use cases of a decade ago, not considering IP compliance or standardized network management and resource orchestration as a must. The Internet Engineering Task Force (IETF) and the 6TiSCH working group (WG) have been actively working on this challenge by designing protocols to bridge the performance of industrial solutions with IP-compliant networks. The effort has resulted in 6TiSCH, a set of specifications that define the IPv6 control plane to manage and orchestrate a TSCH network. 6TiSCH provides the missing elements for zero-configuration TSCH network bootstrap, efficient network access authentication, and distributed and modular scheduling mechanisms. As a cross-layer effort, 6TiSCH leverages and integrates other IETF specifications and the WG has also driven the definition of novel specifications in other IETF WGs. An ultimate goal of this effort is the definition of a fully functional architecture where a combination of IETF protocols enables the envisioned convergence on top of the IEEE industrial standard. This paper introduces the work done by the 6TiSCH WG at IETF, evaluates the performance of the reference implementation, and discusses the 6TiSCH software ecosystem.

6TiSCH is a standardization group within the Internet Engineering Task Force (IETF) that works on IPv6‐enabled Time‐slotted Channel Hopping (TSCH) networks. The 6TiSCH protocol stack, designed by the standardization work at the IETF, has direct applicability to low‐power Internet of Things (IoT) use cases, including smart factory, building, infrastructure and home applications. A key component of the 6TiSCH stack is the Minimal Scheduling Function (MSF). MSF implements a traffic adaptation algorithm which allocates link‐layer resources, that is, cells in the TSCH schedule, according to the traffic load. MAX_NUMCELL is an important parameter defined in the MSF draft standard which determines the length of the running window used to measure cell usage. MSF draft standard does not recommend a value of MAX_NUMCELL to use. This paper provides recommendations on how to choose the value of MAX_NUMCELL, validated through simulation. For periodic traffic, setting MAX_NUMCELL to at least four times the traffic load is recommended to increase efficiency. For bursty traffic, we show that setting MAX_NUMCELL to a small value achieves a low end‐to‐end latency but at high communication overhead. In addition, an improved version of MSF is implemented and tested, which shows a 44% reduction in the communication overhead, considering MAX_NUMCELL = 4, while maintaining the same end‐to‐end latency.

IEEE802.15.4g is a low-power wireless standard initially designed for Smart Utility Networks, i.e., for connecting smart meters. IEEE802.15.4g operates at sub-GHz frequencies to offer 2–3× longer communication range compared to its 2.4 GHz counterpart. Although the standard offers 3 PHYs (Frequncy Shift Keying, Orthogonal Frequency Division Multiplexing and Offset-Quadrature Phase Shift Keying) with numerous configurations, 2-FSK at 50 kbps is the mandatory and most prevalent radio setting used. This article looks at whether IEEE802.15.4g can be used to provide connectivity for outdoor deployments. We conduct range measurements using the totality of the standard (all modulations with all further parametrization) in the 863–870 MHz band, within four scenarios which we believe cover most low-power wireless outdoor applications: line of sight, smart agriculture, urban canyon, and smart metering. We show that there are radio settings that outperform the “2-FSK at 50 kbps” base setting in terms of range, throughput and reliability. Results show that highly reliable communications with data rates up to 800 kbps can be achieved in urban environments at 540 m between nodes, and the longest useful radio link is obtained at 779 m. We discuss how IEEE802.15.4g can be used for outdoor operation, and reduce the number of repeater nodes that need to be placed compared to a 2.4 GHz solution.

We report the first time-synchronized protocol stack running on a crystal-free device. We use an early prototype of the Single-Chip micro Mote, SCμM, a single-chip 2 × 3 mm² mote-on-a-chip, which features an ARM Cortex-M0 micro-controller and an IEEE802.15.4 radio. This prototype consists of an FPGA version of the micro-controller, connected to the SCμM chip which implements the radio front-end. We port OpenWSN, a reference implementation of a synchronized protocol stack, onto SCμM. The challenge is that SCμM has only on-chip oscillators, with no absolute time reference such as a crystal. We use two calibration steps – receiving packets via the on-chip optical receiver and RF transceiver – to initially calibrate the oscillators on SCμM so that it can send frames to an off-the-shelf IEEE802.15.4 radio. We then use a digital trimming compensation algorithm based on tick skipping to turn a 567 ppm apparent drift into a 10 ppm drift. This allows us to run a full-featured standards-compliant 6TiSCH network between one SCμM and one OpenMote. This is a step towards realizing the smart dust vision of ultra-small and cheap ubiquitous wireless devices.