LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s), connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed.

https://www.mdpi.com/1424-8220/16/9/1466/pdf

A Study of LoRa: Long Range & Low Power Networks for the Internet of Things

New Internet of Things (IoT) technologies such as Long Range (LoRa) are emerging which enable power efficient wireless communication over very long distances. Devices typically communicate directly to a sink node which removes the need of constructing and maintaining a complex multi-hop network. Given the fact that a wide area is covered and that all devices communicate directly to a few sink nodes a large number of nodes have to share the communication medium. LoRa provides for this reason a range of communication options (centre frequency, spreading factor, bandwidth, coding rates) from which a transmitter can choose. Many combination settings are orthogonal and provide simultaneous collision free communications. Nevertheless, there is a limit regarding the number of transmitters a LoRa system can support. In this paper we investigate the capacity limits of LoRa networks. Using experiments we develop models describing LoRa communication behaviour. We use these models to parameterise a LoRa simulation to study scalability. Our experiments show that a typical smart city deployment can support 120 nodes per 3.8 ha, which is not sufficient for future IoT deployments. LoRa networks can scale quite well, however, if they use dynamic communication parameter selection and/or multiple sinks.

https://dl.acm.org/doi/pdf/10.1145/2988287.2989163

Do LoRa Low-Power Wide-Area Networks Scale?

LoRaWAN is one of the low power wide area network (LPWAN) technologies that have received significant attention by the research community in the recent years. It offers low-power, low-data rate communication over a wide range of covered area. In the past years, the number of publications regarding LoRa and LoRaWAN has grown tremendously. This paper provides an overview of research work that has been published from 2015 to September 2018 and that is accessible via Google Scholar and IEEE Explore databases. First, a detailed description of the technology is given, including existing security and reliability mechanisms. This literature overview is structured by categorizing papers according to the following topics: (i) physical layer aspects; (ii) network layer aspects; (iii) possible improvements; and (iv) extensions to the standard. Finally, a strengths, weaknesses, opportunities and threats (SWOT) analysis is presented along with the challenges that LoRa and LoRaWAN still face.

https://biblio.ugent.be/publication/8586331/file/8586357.pdf

A Survey of LoRaWAN for IoT: From Technology to Application

LoRa is a long-range, low power, low bit rate and single-hop wireless communication technology It is intended to be used in Internet of Things (IoT) applications involving battery-powered devices with low throughput requirements A LoRaWAN network consists of multiple end nodes that communicate with one or more gateways These gateways act like a transparent bridge towards a common network server The amount of end devices and their throughput requirements will have an impact on the performance of the LoRaWAN network This study investigates the scalability in terms of the number of end devices per gateway of single-gateway LoRaWAN deployments First, we determine the intra-technology interference behavior with two physical end nodes, by checking the impact of an interfering node on a transmitting node Measurements show that even under concurrent transmission, one of the packets can be received under certain conditions Based on these measurements, we create a simulation model for assessing the scalability of a single gateway LoRaWAN network We show that when the number of nodes increases up to 1000 per gateway, the losses will be up to 32% In such a case, pure Aloha will have around 90% losses However, when the duty cycle of the application layer becomes lower than the allowed radio duty cycle of 1%, losses will be even lower We also show network scalability simulation results for some IoT use cases based on real data

https://www.mdpi.com/1424-8220/17/6/1193/pdf

LoRa Scalability: A Simulation Model Based on Interference Measurements

Low-Power Wide-Area Network (LPWAN) technologies such as Long Range (LoRa) are emerging that enable power efficient wireless communication over very long distances. LPWAN devices typically communicate directly to a sink node which removes the need of constructing and maintaining a complex multi-hop network. However, to ensure efficient and reliable communication LPWAN devices often provide a large number of transmission parameters. For example, a LoRa device can be configured to use different spreading factors, bandwidth settings, coding rates and transmission powers, resulting in over 6720 possible settings. It is a challenge to determine the setting that minimises transmission energy cost while meeting the required communication performance. This paper is the first to present a thorough analysis of the impact of LoRa transmission parameter selection on communication performance. We study in detail the impact of parameter settings on energy consumption and communication reliability. Using this study we develop a link probing regime which enables us to quickly determine transmission settings that satisfy performance requirements. The presented work is a first step towards an automated mechanism for LoRa transmission parameter selection that a deployed LoRa network requires, but is not yet specified within the Long Range Wide Area Network (LoRaWAN) framework.

/pdf/lora-transmission-parameter-selection-1kg55vf4fn.pdf

LoRa Transmission Parameter Selection

New transceiver technologies have emerged which enable power efficient communication over very long distances. Examples of such Low-Power Wide-Area Network (LPWAN) technologies are LoRa, Sigfox and Weightless. A typical application scenario for these technologies is city wide meter reading collection where devices send readings at very low frequency over a long distance to a data concentrator (one-hop networks). We argue that these transceivers are potentially very useful to construct more generic Internet of Things (IoT) networks incorporating multi-hop bidirectional communication enabling sensing and actuation. Furthermore, these transceivers have interesting features not available with more traditional transceivers used for IoT networks which enable construction of novel protocol elements. In this paper we present a performance and capability analysis of a currently available LoRa transceiver. We describe its features and then demonstrate how such transceiver can be put to use efficiently in a wide-area application scenario. In particular we demonstrate how unique features such as concurrent non-destructive transmissions and carrier detection can be employed. Our deployment experiment demonstrates that 6 LoRa nodes can form a network covering 1.5 ha in a built up environment, achieving a potential lifetime of 2 year on 2 AA batteries and delivering data within 5 s and reliability of 80%.

/pdf/lora-for-the-internet-of-things-sa4rzmm9z5.pdf

LoRa for the Internet of Things

This paper presents ShapeClip: a modular tool capable of transforming any computer screen into a z-actuating shape-changing display. This enables designers to produce dynamic physical forms by "clipping" actuators onto screens. ShapeClip displays are portable, scalable, fault-tolerant, and support runtime re-arrangement. Users are not required to have knowledge of electronics or programming, and can develop motion designs with presentation software, image editors, or web-technologies. To evaluate ShapeClip we carried out a full-day workshop with expert designers. Participants were asked to generate shape-changing designs and then construct them using ShapeClip. ShapeClip enabled participants to rapidly and successfully transform their ideas into functional systems.

https://dl.acm.org/doi/pdf/10.1145/2702123.2702599

ShapeClip: Towards Rapid Prototyping with Shape-Changing Displays for Designers

A Survey of Systematic Evidence Mapping Practice and the Case for Knowledge Graphs in Environmental Health and Toxicology

A number of security certifications for small- and medium-size enterprises have been proposed, but how effective are these schemes? We evaluated the effectiveness of Cyber Essentials and found that its security controls work well to mitigate threats that exploit vulnerabilities remotely with commodity-level tools.

/pdf/basic-cyber-hygiene-does-it-work-3mtns8pt4z.pdf

Basic Cyber Hygiene: Does It Work?

This article characterizes actuation techniques for generating movement in shape-changing displays with physically reconfigurable geometry. To date, few works in human–computer interaction literature provide detailed and reflective descriptions of the implementation techniques used in shape-changing displays. This hinders the rapid development of novel interactions as researchers must initially spend time understanding technologies before prototyping new interactions and applications. To bridge this knowledge gap, the authors propose a taxonomy that classifies actuator characteristics and simplifies the process for designers to select appropriate technologies that match their requirements for developing shape displays. They scope the investigation to linear actuators that are used in grid configurations. The taxonomy is validated by (a) examining current implementation techniques of motorized, pneumatic, hydraulic, magnetic, and shape-memory actuators in the literature, (b) constructing prototypes...

/pdf/a-characterization-of-actuation-techniques-for-generating-4m94x2fnsx.pdf

John Vidler

Papers

LoRa for the Internet of Things

ShapeClip: Towards Rapid Prototyping with Shape-Changing Displays for Designers

A Survey of Systematic Evidence Mapping Practice and the Case for Knowledge Graphs in Environmental Health and Toxicology

Basic Cyber Hygiene: Does It Work?

A Characterization of Actuation Techniques for Generating Movement in Shape-Changing Interfaces