Design and evaluation of innovative protocols for LoRa

This paper proposes a low power application dedicated protocol stack which consists of a contention-constrained p-CSMA (CCP) protocol over the LoRa modulation technique and a consecutive successful transmission controlled transport (CSTCT) protocol. The aim of these innovative protocols is to boost the network performance in terms of throughput and energy consumption while the transmission latency is still acceptable. As a reference, firstly, p-CSMA is evaluated with the consideration of under-noise-level communication. Then, the CCP protocol is proposed with the consideration of the speciality of the carrier sensing feature provided by the LoRa modem, which differs from the traditional energy level detection carrier sensing method. The CSTCT protocol resides at the CCP MAC layer which is light-weight and devised to further improve the overall throughput. The performance of the protocol stack is evaluated in simulations using various settings with predefined parameters that are drawn from experiments. The results show that our CCP MAC protocol and CSTCT transport protocol provide 10% higher throughput compared to the classic p-CSMA when the offered load is lower than 1.3 while the energy consumption is reduced by a factor of 2 and it remains latency limited.