Optimizing NB-IoT Communication Patterns for Permanently Connected mMTC Devices

The new types of industry-driven applications that need to be supported by low-power wide-area networks (LP-WANs), such as remote control or metering of devices within the massive machine-type infrastructures (e.g., Smart Grids), require a permanent connection to the remote server. In addition, there is also a shift in the communication paradigm, as the user equipment (UE) nodes are queried in regular and frequent intervals. Notably, the presence of this type of traffic may drastically deteriorate the performance of LPWAN technologies initially developed to support conventional use-cases characterized by non-synchronized transmissions. Though none of the LPWAN technologies is inherently designed to handle such demanding communication patterns, the narrowband Internet of things (NB-IoT) still stands for the best candidate as it operates within the license frequency spectrum. To optimize the delay performance of both types of traffic coexisting at the NB-IoT air interface, we propose an approach based on spreading the message transmission time instants of regular and stochastic traffic. We show an optimal value of the spreading interval minimizing the message transmission delay of regular traffic and propose a mathematical model to estimate its value. By parameterizing the model using a detailed measurements campaign of NB-IoT, we show that the optimal value of spreading interval and associated mean message delay is a linear function of the number of UEs. We report these values for a wide range of UEs in the coverage area of the NB-IoT base station and show that conventional stochastic traffic does not influence regular traffic performance.acceptedVersionPeer reviewe

Performance Analysis of Different LoRaWAN Frequency Bands for mMTC Scenarios

The possibility of utilizing different frequencies for the LoRaWAN is a key component which, together with the other parameters, i.e., (i) bandwidth, (ii) spreading factor, (iii) coding rate, and (iv) transmission power, defines the communication performance. In this paper, we present the substantive im- provements for both the end devices and the radio access network (gateways) to enhance the data rates and decrease the communication latency. The implementation changes were made for the publicly available LoRaWAN module “signetlabdei” for Network Simulator 3. Utilizing the frequency 2.4GHz, the transmission time in the LoRaWAN network has improved by 80 % decreasing from 75 ms to 14 ms. The frequency 2.4 GHz for the EU region also showed the best performance due to the extended bandwidth (transmission success above 90%) in the case of the mMTC scenario with thousands of devices deployed. Together with the updated LoRaWAN module, the reported results are expected to serve as a building block for mMTC- oriented simulation scenarios.acceptedVersionPeer reviewe

On the performance of narrow-band internet of things (NB-IoT) for delay-tolerant services

Narrowband IoT (NB-IoT) stands for a radio access technology standardized by the 3GPP organization in Release 13 to enable a large set of use-cases for massive Machine-type Communications (mMTCs). Compared to legacy human-oriented 4G (LTE) communication systems, NB-IoT has game-changing features in terms of extended coverage, enhanced power saving modes, and a reduced set of available functionality. At the end of the day, these features allow for connectivity of devices in challenging positions, enabling long battery life and reducing device complexity. This article addresses the development of the universal testing device for delay-tolerant services allowing for in-depth verification of NB-IoT communication parameters. The presented outputs build upon our long-term cooperation with the Vodafone Czech Republic a.s. company.acceptedVersionPeer reviewe

Pitfalls of LPWA Power Consumption: Hands-On Design of Current Probe

The unique opportunities introduced by the emerging Industrial Internet of Things (IIoT) applications have accelerated the momentum of the massive Machine-Type Communications (mMTC) worldwide. As the number of already deployed Low-Power Wide-Area (LPWA) applications growth exponentially over the last decade, new open challenges started to be discussed across the industry sector. The most critical parameter of the LWPA devices in question is energy efficiency and the overall power consumption of designed end-devices. Therefore, the need for precise measurement of power consumption has attracted engineers’ attention as the unique communication parameters of the LPWA devices form the current consumption measurements challenging task. To facilitate accurate current measurements ranging between hundreds of nA and hundreds of µA, we propose a unique design of the current probe prototype. We then demonstrate the obtained results concerning the accuracy, measurement range switching, and sufficient sampling speed. All the measurements from the designed prototype are further compared with the industry-grade DC power analyzer Agilent N6705B.acceptedVersionPeer reviewe

A perspective on wireless M-bus for smart electricity grids

The Internet of Things (IoT) enables long-range outdoor networks, such as smart grid and municipal lighting, as well as short-range indoor systems for smart homes, residential security, and energy management. Wireless connectivity and standardized communication protocols become an essential technology baseline for these diverse IoT applications. The focus of this work is wireless connectivity for smart metering systems. One of the recent protocols in this field is Wireless M-BUS, which is being widely utilized for remote metering applications across Europe. Therefore, in this paper, we detail a novel multi-platform framework designed to serve as a data generator for the protocol in question. The developed software allows to construct Wireless M-Bus telegrams with a high level of detail according to the EN 13757-4 specification and then schedule them for periodic transmission. The evaluation of the data generator is done in real scenario by using previously developed prototype equipped with IQRF TR72DA communication module acting as a smart meter with implemented software framework. As a result, the evaluation of communication distance between the developed Wireless MBus prototype and commercial gateway was tested in case of indoor scenario at Brno University of Technology, Faculty of Electrical Engineering and Communication.acceptedVersionPeer reviewe

Unifying multi-radio communication technologies to enable mMTC applications in B5G networks

Abstract Even though the wireless communication technologies have evolved significantly in the last decade, the performance requirements of versatile massive Machine-Type Communication (mMTC) use-cases grow at even faster pace. For this reason, the challenge of providing energy-efficient, reliable, secure, and variable devices with ubiquitous connectivity cannot be addressed by any single Radio Access Technology (RAT) available today. Therefore, the concept of multi-RAT devices in the context of next-generation communication technologies (5G and beyond 5G (B5G)) comes into play. In this paper, we investigate the utility of multi-RAT IoT connectivity in practice with respect to a Smart City scenario, in which the location of public transport vehicles e.g., trams and buses is tracked and reported by a device equipped with two Low-Power Wide-Area Network (LPWAN) technologies i.e., Narrowband IoT (3rd Generation Partnership Project (3GPP)) and LoRaWAN (non-3GPP). Both technologies got matured and have shown their momentum in the recent years, and are expected to play the key role also in the future. We first detail the constructed multi-RAT prototype and then report the initial results of its evaluation in a pilot deployment in the city of Brno, Czech Republic. The obtained results illustratively confirm the feasibility of joint usage of two diverse LPWAN RATs while their combination brings higher flexibility, reliability, and improve the overall Quality of Service (QoS) to wireless connectivity

On the performance of multi-gateway LoRaWAN deployments:an experimental study

Abstract A remarkable progress in the Low Power Wide Area Network (LPWAN) technologies over the recent years opens new opportunities for developing versatile massive Internet of Things (IoT) applications. In this paper, we focus on one of the most popular LPWAN technologies operating in the license-exempt frequency bands, named LoRaWAN. The key contribution of this study is our unique set of results obtained during an extensive measurement campaign conducted in the city of Brno, Czech Republic. During a three-months-period, the connectivity of a public Long Range Wide Area Network (LoRaWAN) with more than 20 gateways (GWs) was assessed at 231 test locations. This paper presents an analysis of the obtained results, aimed at capturing the effects related to the spatial diversity of the GW locations and the real-life multi-GW network operation with all its practical features. One of our findings is the fact that only for 47% tested locations the GW featuring the minimum geographical distance demonstrated the highest received signal strength and signal-to-noise ratio (SNR). Also, our results captured and characterized the variations in the received signal strength indicator (RSSI) and SNR as a function of the communication distance in an urban environment, and illustrated the distribution of the spreading factors (SFs) as a result of the adaptive data rate (ADR) algorithm operation in a real-life multi-GW deployment

Communication performance of a real-life wide-area low-power network based on Sigfox technology

Abstract In this paper, we study real-world performance of Sigfox, which is one of the most mature Low-Power Wide-Area Network (LPWAN) technologies that operate in unlicensed frequency bands. During an extensive measurement campaign conducted over three months in the city of Brno, Czech Republic, we assessed the communication performance and the radio channel properties in 311 different test locations. We observed that despite the challenging natural landscape and urban environment of the test area, more than 94% of the packets sent were received successfully, with at least one packet delivered from 297 out of 311 tested locations. Our results also reported experiment-based radio channel and signal-to-noise characterization as well as provided insights into the efficiency of two crucial mechanisms used by Sigfox to improve the packet delivery — packet repetition and multi-gateway reception. Finally, we employed our experimental data to understand the efficiency of two non-fingerprint localization methods based on received signal strength indicator in a practical Sigfox network