Towards LoRaWAN without Data Loss: Studying the Performance of Different Channel Access Approaches

Abstract

The Long Range Wide Area Network (LoRaWAN) is one of the fastest growing Internet of Things (IoT) access protocols. It operates in the license free 868 MHz band and gives everyone the possibility to create their own small sensor networks. The drawback of this technology is often unscheduled or random channel access, which leads to message collisions and potential data loss. For that reason, recent literature studies alternative approaches for LoRaWAN channel access. In this work, state-of-the-art random channel access is compared with alternative approaches from the literature by means of collision probability. Furthermore, a time scheduled channel access methodology is presented to completely avoid collisions in LoRaWAN. For this approach, an exhaustive simulation study was conducted and the performance was evaluated with random access cross-traffic. In a general theoretical analysis the limits of the time scheduled approach are discussed to comply with duty cycle regulations in LoRaWAN.

Advancing Digital Twin-Based Collision Avoidance: A Comprehensive Analysis of Communication Networks for Safety-Critical Applications in Industry 4.0

“…The authors of [ 27 ] explore strategies aimed at preventing collisions in LoRaWAN channels and assess the impact of unavoidable random access cross-traffic on such strategies. They provide guidelines on how to implement these strategies, introducing a time-scheduled channel access approach.…”

Plan the Access? Generic Hardware Independent Energy Consumption and Efficiency Model for Different LoRaWAN Channel Access Approaches

“…Messages in LoRa contain a preamble and 4.25 symbols for synchronization, followed by an optional header, and the actual payload [7]. The typical preamble length is eight symbols and 20 bits for the header.…”

“…For that reason, we only analyze a single one and assume extrapolation to the other channels is valid. Similarly, it is done in literature studying message transmission, channel access, or LoRaWAN data transmission quality in general [13], [7], [15].…”

“…This increases the overhead in comparison to slotted ALOHA since each sensor has a pre-defined slot for its transmission and can not simply select the next slot. However, in theory, this approach can avoid message collision completely and increase the error-free throughput significantly [7].…”

“…Despite the benefits of a simple and cost-effective Lo-RaWAN, the current random channel access lacks interference protection, resulting in message collisions and data loss. To address this issue, research focuses on improved LoRaWAN channel access, specifically listen before talk and time scheduling [6], [7], [8]. However, additional functionality introduces complexity and impacts the energy consumption of end device.…”