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.
18 July 2018 in IEEE Transactions on Industrial Informatics
Wireless industrial networks require reliable and deterministic communication. Determinism implies that there must be a guarantee that each data packet will be delivered within a bounded delay. Moreover, it must ensure that the potential congestion or interference will not impact the predictable properties of the network. In 2016, IEEE 802.15.4 time-slotted channel hopping (TSCH) emerged as an alternative medium access control to the industrial standards such as WirelessHART and ISA100.11a. However, TSCH is based on traditional collision detection and retransmission, and cannot guarantee reliable delivery within a given time. This paper proposes LeapFrog Collaboration (LFC) to provide deterministic and reliable communication over a routing protocol (RPL) based network. LFC is a novel multipath routing algorithm that takes advantage of route diversity by duplicating the data flow onto an alternate path. Simulations and analytical results demonstrate that LFC significantly outperforms the single-path retransmission-based approach of RPL + TSCH and the state-of-the-art LinkPeek solution.
With current Network Mobility (NEMO) Basic Support, all communications to and from Mobile Network Nodes must go through the Mobile Router and Home Agent (MRHA) tunnel when the mobile network is away. This results in increased length of packet route and increased packet delay in most cases. To overcome these limitations, one might have to turn to Route Optimization (RO) for NEMO. This memo documents various types of Route Optimization in NEMO and explores the benefits and tradeoffs in different aspects of NEMO Route Optimization.
Estimating channel conditions to predict packet delivery can be exploited as a powerful tool to ensure wireless networks dependability. In this article we explore the practical application of this idea from the end-device perspective, using the LoRaWAN protocol stack. We aim to understand if packet delivery can be estimated considering different levels of feedback at the end-device. For that, an extensive data collection campaign is carried out. Through an analysis of the obtained traces, we establish correlations between connectivity metrics at the end node and the fact that a packet is received at the gateway. The study is complemented considering different levels of feedback: (i) No feedback, (ii) enabling acknowledgements frames, and (iii) considering application/control plane data about the channel status at the gateway side. The results show that it is possible to estimate packet delivery in all the evaluated cases.
The NEMO Basic Support (NEMO BS) protocol provides a technique for enabling entire networks of IPv6 hosts to gain Internet access and remain reachable via constant, unaltered addresses whilst their underlying location in the Internet changes. In addition to individual hosts, this NEMO model also supports entire mobile networks connecting to other mobile networks, resulting in topologies known as Nested NEMO networks. In this paper we explain the inefficiencies that arise if NEMO BS is used to support this type of scenario and introduce our NEMO+ suite of protocols which are designed to optimise performance in Nested NEMO networks. We detail the Tree Discovery (TD), Network In Node Advertisement (NINA) and Reverse Routing Header (RRH) protocols that make up the NEMO+ suite and provide experimental evaluation results from a testbed comprising of our two distinct protocol implementation platforms (Linux and Cisco IOS). In addition we present simulation results based on scenarios of mass deployment of NEMO+ enabled mobile networks in order to determine the feasibility of our approach to efficiently support Nested NEMO networks