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Author

Martin Bor

Other affiliations: Delft University of Technology
Bio: Martin Bor is an academic researcher from Lancaster University. The author has contributed to research in topics: Smart grid & Wireless sensor network. The author has an hindex of 6, co-authored 12 publications receiving 984 citations. Previous affiliations of Martin Bor include Delft University of Technology.

Papers
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Proceedings ArticleDOI
13 Nov 2016
TL;DR: This paper develops models describing LoRa communication behaviour and uses these models to parameterise a LoRa simulation to study scalability, showing that a typical smart city deployment can support 120 nodes per 3.8 ha, which is not sufficient for future IoT deployments.
Abstract: 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.

593 citations

Proceedings ArticleDOI
15 Feb 2016
TL;DR: A performance and capability analysis of a currently available LoRa transceiver is presented and it is demonstrated how unique features such as concurrent non-destructive transmissions and carrier detection can be employed in a wide-area application scenario.
Abstract: 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%.

306 citations

Proceedings ArticleDOI
05 Jun 2017
TL;DR: This paper is the first to present a thorough analysis of the impact of LoRa transmission parameter selection on communication performance, and develops a link probing regime which enables us to quickly determine transmission settings that satisfy performance requirements.
Abstract: 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.

216 citations

Proceedings ArticleDOI
20 Feb 2017
TL;DR: The use of directional antennae and the use of multiple base stations as methods of dealing with inter-network interference are investigated to show that both methods are able to improve LoRa network performance in interference settings.
Abstract: Long Range (LoRa) is a popular technology used to construct Low-Power Wide-Area Networks (LPWAN). Given the popularity of LoRa it is likely that multiple independent LoRa networks are deployed in close proximity. In this situation, neighbouring networks interfere and methods have to be found to combat this interference. In this paper we investigate the use of directional antennae and the use of multiple base stations as methods of dealing with inter-network interference. Directional antennae increase signal strength at receivers without increasing transmission energy cost. Thus, the probability of successfully decoding the message in an interference situation is improved. Multiple base stations can alternatively be used to improve the probability of receiving a message in a noisy environment. We compare the effectiveness of these two approaches via simulation. Our findings show that both methods are able to improve LoRa network performance in interference settings. However, the results show that the use of multiple base stations clearly outperforms the use of directional antennae. For example, in a setting where data is collected from 600 nodes which are interfered by four networks with 600 nodes each, using three base stations improves the Data Extraction Rate (DER) from 0.24 to 0.56 while the use of directional antennae provides an increase to only 0.32.

126 citations

Proceedings ArticleDOI
11 Jun 2012
TL;DR: This study investigates the performance of radios operating on the alternative 868 MHz frequency band, which is basically noise-free as determined from extensive experiments on a large-scale indoor testbed featuring more than 100 nodes.
Abstract: Lossy links are one of the fundamental characteristics of wireless sensor networks (WSNs). A large amount of work has been performed on characterizing link properties of 802.15.4 radios, in particular in the 2.4 GHz band. Unfortunately, the 2.4 GHz band has the apparent disadvantage of a crowded spectrum and considerable external interference, e. g., from WiFi, Bluetooth or even microwave ovens. We therefore investigate the performance of radios operating on the alternative 868 MHz frequency band, which is basically noise-free as determined from extensive experiments on a large-scale indoor testbed featuring more than 100 nodes. Although the lack of external interference eases protocol design, our study reveals that - and characterizes to what extent - wireless links in the 868 MHz band still show large variations in performance that must be accounted for.

29 citations


Cited by
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Journal ArticleDOI
TL;DR: The design goals and the techniques, which different LPWA technologies exploit to offer wide-area coverage to low-power devices at the expense of low data rates are presented.
Abstract: Low power wide area (LPWA) networks are attracting a lot of attention primarily because of their ability to offer affordable connectivity to the low-power devices distributed over very large geographical areas. In realizing the vision of the Internet of Things, LPWA technologies complement and sometimes supersede the conventional cellular and short range wireless technologies in performance for various emerging smart city and machine-to-machine applications. This review paper presents the design goals and the techniques, which different LPWA technologies exploit to offer wide-area coverage to low-power devices at the expense of low data rates. We survey several emerging LPWA technologies and the standardization activities carried out by different standards development organizations (e.g., IEEE, IETF, 3GPP, ETSI) as well as the industrial consortia built around individual LPWA technologies (e.g., LoRa Alliance, Weightless-SIG, and Dash7 alliance). We further note that LPWA technologies adopt similar approaches, thus sharing similar limitations and challenges. This paper expands on these research challenges and identifies potential directions to address them. While the proprietary LPWA technologies are already hitting the market with large nationwide roll-outs, this paper encourages an active engagement of the research community in solving problems that will shape the connectivity of tens of billions of devices in the next decade.

1,362 citations

Journal ArticleDOI
09 Sep 2016-Sensors
TL;DR: An overview of LoRa and an in-depth analysis of its functional components are provided and some possible solutions for performance enhancements are proposed.
Abstract: 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.

1,126 citations

Proceedings ArticleDOI
13 Nov 2016
TL;DR: This paper develops models describing LoRa communication behaviour and uses these models to parameterise a LoRa simulation to study scalability, showing that a typical smart city deployment can support 120 nodes per 3.8 ha, which is not sufficient for future IoT deployments.
Abstract: 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.

593 citations

Proceedings ArticleDOI
25 Mar 2012
TL;DR: The frequency diversity of the subcarriers in OFDM systems is explored and a novel approach called FILA is proposed, which leverages the channel state information (CSI) to alleviate multipath effect at the receiver, which can significantly improve the localization accuracy compared with the corresponding RSSI approach.
Abstract: Indoor positioning systems have received increasing attention for supporting location-based services in indoor environments. WiFi-based indoor localization has been attractive due to its open access and low cost properties. However, the distance estimation based on received signal strength indicator (RSSI) is easily affected by the temporal and spatial variance due to the multipath effect, which contributes to most of the estimation errors in current systems. How to eliminate such effect so as to enhance the indoor localization performance is a big challenge. In this work, we analyze this effect across the physical layer and account for the undesirable RSSI readings being reported. We explore the frequency diversity of the subcarriers in OFDM systems and propose a novel approach called FILA, which leverages the channel state information (CSI) to alleviate multipath effect at the receiver. We implement the FILA system on commercial 802.11 NICs, and then evaluate its performance in different typical indoor scenarios. The experimental results show that the accuracy and latency of distance calculation can be significantly enhanced by using CSI. Moreover, FILA can significantly improve the localization accuracy compared with the corresponding RSSI approach.

359 citations

Journal ArticleDOI
16 Nov 2018-Sensors
TL;DR: A detailed description of the technology is given, including existing security and reliability mechanisms, and a strengths, weaknesses, opportunities and threats (SWOT) analysis is presented along with the challenges that LoRa and LoRaWAN still face.
Abstract: 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.

347 citations