Channel Hopping Networks Research Articles

Contention-Based Proportional Fairness (CBPF) Transmission Scheme for Time Slotted Channel Hopping Networks

Time slotted channel hopping (TSCH) is a mediumaccess control (MAC) protocol introduced in IEEE802.15.4e standard, addressing low-power requirements of the Internet of Things and low-power and lossy networks. The 6TiSCH operation (6top) sublayer of IEEE802.15.4e defines the schedule that includes sleep, transmit, and receive routines of the nodes. However, the standard does not specify the design of the schedule. In this article, we propose a contention-based proportional fairness transmission scheme for TSCH networks to maximize the system throughput addressing the fair allocation of resources to the nodes. We propose a convex programming-based method to achieve the fairness and throughput objectives. We model TSCH MAC as a multichannel slotted ALOHA and analyze it for a schedule given by the 6top layer. Performance metrics, such as throughput, delay, and energy spent per successful transmission, are derived and validated through simulations and real-time testbed implementations.

Low-delay fair-reliability scheduling in multi-hop IEEE802.15.4e time synchronised channel hopping networks

Low-delay fair-reliability scheduling in multi-hop IEEE802.15.4e time synchronised channel hopping networks

Low-delay fair-reliability scheduling in multi-hop IEEE802.15.4e time synchronised channel hopping networks

IEEE802.15.4e is the latest generation of high-reliability, low-power medium access control protocols. As part of IEEE802.15.4e, time synchronised channel hopping (TSCH) provides support for multi-...

Robotic‐aided IoT: automated deployment of a 6TiSCH network using an UGV

The automated setup of Internet of things (IoT) systems in industrial environments is an open challenge at the forefront of networking and robotics domains. In this study, a robotic-aided deployment system is proposed and experimentally tested with reference to the Internet protocol version 6 technology. To this end, a design methodology has been conceived to attain the setup of a fully connected time-slotted channel hopping network in a target area, based on the measured received signal strength indication of wireless links, required spatial sensing resolution, and number of available IoT nodes. To demonstrate the effectiveness of the proposed methodology, an experimental test bed has been set up, consisting of an unmanned ground vehicle (UGV) that automatically deploys an IoT network in a laboratory environment. Experimental results clearly show that the UGV is able to deploy a fully connected 6TiSCH network that match spatial resolution requirements, highlighting how the proposed policy affects the position of IoT nodes release points.

A virtual slotframe technique for reliable multi-hop IEEE 802.15.4e time-slotted channel hopping network

Time-slotted channel hopping is one of the medium access control modes defined in IEEE 802.15.4e. Although time-slotted channel hopping provides high reliability, it cannot be achieved automatically. A time-slotted channel hopping should be configured properly according to the dynamic changes in a network. When new devices participate in the network or the data traffic is increased, link allocation may not be possible due to the fixed slotframe length. The simplest way to acquire additional links is to change the length. However, the conventional method to change this length involves significant overhead and the possibility of link failures. In this article, we evaluate the performance of the conventional IEEE 802.15.4e method and analyze the problems that can occur when changing the slotframe length. To resolve these problems, we propose a virtual slotframe technique that forms a logical slotframe by connecting multiple slotframes. A slot scheduler will then perceive the virtual slotframe as merely a long slotframe. The devices can translate the schedules made for the longer slotframe into real links using the virtual slotframe technique. These features allow the time-slotted channel hopping network to allocate additional slots without reconfiguration. The simulation results show that the proposed technique is a maximum of 18 times and an average of 10 times faster than the conventional method.

A performance analysis of Orchestra scheduling for time‐slotted channel hopping networks

The IEEE 802.15.4 TSCH (Time Slotted Channel Hopping) represents the latest generation of low‐power and highly reliable medium‐access control (MAC) protocols. It orchestrates the medium access according to a time‐frequency communication schedule. However, TSCH specification does not provide any practical solution for the establishment of the schedule. Orchestra is a recent scheduling solution for TSCH that brings significant advantages such as, the use of simple scheduling rules, the low signaling overhead, and the high delivery ratio it is able to fulfill. In this paper, we investigate the use of TSCH protocol with Orchestra scheduling approach for the Internet of Things (IoT) applications. Performance analysis results demonstrate that despite its unique features, Orchestra may incur high end‐to‐end communication delay, especially when the traffic is not uniformly distributed in the network. This limitation makes Orchestra not sufficiently convenient for several delay‐sensitive IoT applications, such as smart grid applications.

A rapid joining scheme based on fuzzy logic for highly dynamic IEEE 802.15.4e time-slotted channel hopping networks

The IEEE 802.15.4e standard is an amendment of the IEEE 802.15.4-2011 protocol by introducing time-slotted channel hopping access behavior mode. However, the IEEE 802.15.4e only defines time-slotted channel hopping link-layer mechanisms without an investigation of network formation and communication scheduling which are still open issues to the research community. This article investigates the network formation issue of the IEEE 802.15.4e time-slotted channel hopping networks. In time-slotted channel hopping networks, a joining node normally takes a long time period to join the network because the node has to wait until there is at least one enhanced beacon message advertised by synchronized nodes (synchronizers) in the network on its own synchronization channel. This leads to a long joining delay and high energy consumption during the network formation phase, especially so in highly dynamic networks in which nodes join or rejoin frequently. To enable a rapid time-slotted channel hopping network formation, this article proposes a new design for slotframe structure and a novel adaptive joining scheme based on fuzzy logic. Our proposed scheme enables a synchronizer to be able to adaptively determine an appropriate number of enhanced beacons it should advertise, based on the number of available synchronizers in the network, so that joining nodes can achieve a short joining time while energy consumption of enhanced beacon advertisement at the synchronizers is optimized. Through extensive mathematical analysis and experimental results, we show that the proposed scheme achieves a significant improvement in terms of joining delay compared to state-of-the-art studies.

Link‐layer security in TSCH networks: effect on slot duration

AbstractThe IEEE802.15.4e‐2012 standard is widely used in multi‐hop wireless industrial Internet of things applications. In the time‐slotted channel hopping mode, nodes are synchronised, and time is cut into timeslots. A schedule orchestrates all communications, resulting in high reliability and low power operations. A timeslot must be long enough for a node to send a data frame to its neighbour, and for that neighbour to send back an acknowledgement. Shorter timeslots enable higher bandwidth and lower latency, yet the minimal timeslot duration is limited by how long link‐layer security operations take. We evaluate the overhead of link‐layer security in time‐slotted channel hopping networks in terms of minimal timeslot length, memory footprint and energy consumption. We implement full link‐layer security on a range of hardware platforms, exploring different hardware/software implementation strategies. Through an extensive measurement campaign, we quantify the advantage of hardware accelerations for link‐layer security and show how the minimal duration of a timeslot varies between 9 and 88ms for the most common configuration, depending on hardware support. Furthermore, we also highlighted the impact that the timeslot duration has on both high‐level application design and energy consumption. Copyright © 2016 John Wiley & Sons, Ltd.