Augmenting LoRaWAN Performance With Listen Before Talk

Abstract

Standard LoRaWANs leverage pure ALOHA at the medium access control layer which is proved to be a performance bottleneck as the network size scales up. Stimulated by this fact, this work studies the applicability and the performance of Listen Before Talk (LBT) medium access schemes in the context of LoRaWANs; we consider two different implementations of LBT: physical layer LBT based on energy detection only, and MAC layer LBT based on layer-2 frame decoding, and we propose a Markovian framework to evaluate the performance of LoRaWANs under such setting in terms of Data Extraction Rate and average delay experienced by transmitted uplink messages. The proposed framework is also leveraged to assess the performance of "mixed" LoRaWAN scenarios where some devices access the channel according to the standard-compliant ALOHA protocol, while other devices transmit according to LBT.

Comparative Assessment of the LoRaWAN Medium Access Control Protocols for IoT: Does Listen before Talk Perform Better than ALOHA?

“…We set the transmission power to 14 dBm (i.e., 25 mW). Such a value is compliant with the ETSI regulations and was adopted in several works in the relevant literature, such as [36,43].…”

“…Another interesting topic that is relevant to the two protocols considered in this paper is the coexistence on the same network of devices working according to ALOHA-based and LBT-based access schemes. For example, the works in [35,36] address the performance evaluation of mixed networks in which the ALOHA and LBT approaches coexist. However, the above-mentioned works do not deal with the limitations imposed by the recent ETSI regulations defined in [21,22], while this work gives a detailed overview of the current ETSI regulations.…”

“…However, the above-mentioned works do not deal with the limitations imposed by the recent ETSI regulations defined in [21,22], while this work gives a detailed overview of the current ETSI regulations. Moreover, the works in [35,36] do not provide a comparison between the two kinds of MAC protocols for LoRaWAN in the same conditions. Conversely, this paper provides a performance comparison of LoRa networks using either the ALOHA-based protocol or the LBT-based protocol used in compliance with the ETSI regulations.…”

Unsupervised Learning Clustering and Dynamic Transmission Scheduling for Efficient Dense LoRaWAN Networks

“…For that, this work scenario considers two sets of random values (A) and (B) that are assigned to each node n i following random-uniform distribution 2 . The node n i transmits these values to the gateway GW, where the clustering is formed.…”

“…However, one main drawback associated with LoRaWAN is the vulnerability to high packet collision rate. This is due to the adaption of ALOHA communication protocol, where LoRa nodes initiate packet transmissions without the presence of Listen Before Talk (LBT) protocol [2], [3]. As a result, LoRaWAN efficiency suffers a depreciation, particularly on network's energy consumption and transmission delay.…”