Medium access control in LoRa networks with multiple low-cost gateways

• Autor(a) principal: Figueiredo, Alexandre Daniel Gomes
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/31278
• topic: LoRa; Low power wide area networks; Internet of things; Medium access control protocol; Large scale networks; Multiple gateway network; Singlechannel

With the emergence of Low Power Wide Area Network (LPWAN) technologies, as support to Internet of Things (IoT) applications, Long-Range (LoRa) popularity emerged, being actually one of the most up-and-coming LPWAN technologies, despite the low-rate transmissions and duty-cycle restrictions. Such recognition is due to LoRa's suitable characteristics for large-scale IoT networks, which span from long-range communications, guaranteed by its proprietary modulation scheme, to low power consumption, a fundamental feature for IoT sensor networks. The focus of this dissertation is the study of medium access control strategies in large-scale single-channel LoRa networks with multiple gateways with respect to the amount of delivered useful information and network access fairness. Firstly, it is proposed and analysed a medium access control strategy for LoRa networks with multiple single-channel gateways and the same transmission parameters are used by the entire network. It is based on the pure- ALOHA protocol used in LoRa, and each end-device uses control packets to advertise its transmissions. In the following, a new access strategy based on channel hopping is proposed. In this, each ED uses the transmission characteristics that are most convenient to it, with respect to the signal's quality with the single-channel GWs that are in its communication range. These strategies aimed to increase the efficiency of the network, allowing end-devices to transmit faster and increasing the percentage of successfully transmitted packets by reducing the amount of collisions, given the regulation of the competition in the access to the transmission medium.