Medium access control for large scale LoRa networks

• Autor(a) principal: Fernandes, Rui Pedro Castro
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/29727
• topic: LoRa; Low Power Wide Area Networks; Long Range Communications; Medium Access Control; Internet of Things

LoRa technology has recently gained popularity, attesting itself as one of the most promising and widely adopted Low Power Wide Area Networks (LPWANs). Highly compatible with Internet of Things (IoT) applications and urban environments, this technology enables large range communications although with low data-rates and duty-cycle restrictions. The work developed in this dissertation targets the medium access in LoRa, focusing on its performance in delivering data, especially in large-scale networks. To do so, it is proposed: (1) a probabilistic packet collision model that estimates the success delivery of two or more LoRa concurrent transmissions, based on an exhaustive evaluation of the packet capture effect; (2) an adaptation of LoRa’s state of the art Medium Access Control (MAC) protocol, LoRaWAN, through the use of control packets; and lastly, (3) a new MAC protocol, denoted as LoRa Mode Adaptive Protocol (LoRa-MAP), that manages to maintain the best possible connection between end-nodes and the gateway by changing LoRa’s physical layer parameters. An analysis on different medium access schemes is conducted, aiming to perceive how different parameters and network layouts influence the information exchange process. The performed evaluations, that consider the results obtained from the real capture effect characterization, showed that the proposed MAC solution increases the LoRa network scalability, deeming it a great candidate for IoT environments.