LoRa Beyond ALOHA: An Investigation of Alternative Random Access Protocols

In this article, we present a stochastic geometry-based model to investigate alternative medium access choices for LoRaWAN-a widely adopted low-power wide-area network (LPWAN) technology the Internet-of-Things. LoRaWAN adoption is driven by its simplified architecture, air interface, and access. The physical layer, known as Long Range (LoRa), provides quasi-orthogonal virtual channels through spreading factors (SFs) time-power capture gains. However, pure ALOHA mechanism suffers, in terms of scalability, under same-channel same-SF transmissions from large number devices. our objective explore mechanisms beyond-ALOHA LoRaWAN. Using recent results on time- power-capture effects LoRa, develop unified comparative study other choices, i.e., slotted carrier-sense multiple (CSMA). includes necessary design parameters these mechanisms, such guard time synchronization accuracy ALOHA, carrier sensing threshold CSMA. It also accounts spatial interaction devices annular shaped regions, characteristic performance metrics derived coverage probability, channel throughput, energy efficiency are validated using Monte-Carlo simulations. Our analysis shows that indeed has higher reliability than but at cost lower low device densities. Whereas, CSMA outperforms smaller SFs efficiency, with degrading SFs.