TSLoRa: Timeslotted LoRaWAN for the Industrial Internet of Things Abstract   Automation and data capture in manufacturing, known as Industry 4.0, requires the deployment of a large number of wireless sensor devices in industrial environments. These devices have to be connected via a reliable, lowlatency, lowpower and low operatingcost network. Although LoRaWAN provides a lowpower and reasonablecost network technology, its current ALOHAbased MAC protocol limits its scalability and reliability. A common practice in wireless networks is to solve this issue and improve scalability through the use of timeslotted communications. However, any timeslotted approach comes with overheads to compute and disseminate the transmission schedule in addition to ensuring global time synchronisation. Affording these overheads is not straight forward with LoRaWAN restrictions on radio dutycycle and downlink availability. Therefore, in this work, we propose TSLoRa, an approach that tackles these overheads by allowing devices to selforganise and determine their slot positions in a frame autonomously. In addition to that, only one dedicated slot in each frame is used to ensure global synchronisation and handle acknowledgments. Our experimental results with 25 nodes show that TSLoRa can achieve more than 99% packet delivery ratio even for the most distant nodes. Moreover, our simulations with a higher number of nodes revealed that TSLoRa exhibits a lower energy consumption than the confirmable version of LoRaWAN while not compromising the packet delivery ratio.

Experimental Evaluation on NBIoT and LoRaWAN for Industrial and IoT Applications Low power and longrange communications are essential features of the Internet of Things (IoT) paradigm that is becoming widespread across a spectrum of industrial applications. In this paper, we present performance evaluation of the most promising longrange communication technologies, namely LoRaWAN and NBIoT. We present accurate infield measurements using a monitoring application as a testbench for a fair comparison in terms of energy efficiency and lifetime. Experimental results highlight that NBIoT payload length does not impact on transmission energy. Thus, applications that implement buffering and caching techniques are favored. On the other hand, LoRaWAN consumes 10xc3x97 less energy to transmit a payload equivalent to that of NBIoT, thereby allowing longer enddevice lifetime.