Design of a Robust MAC Protocol for LoRa

Low-power wide-area networks enable large-scale deployments of low-power wireless devices. LoRaWAN is a long-range technology that has emerged as and low data rate solution to support Internet Things applications. Although provides cost-efficient networking solution, recent literature shows it performs poorly in terms reliability security dense due the uncoordinated (ALOHA-based) nature MAC (medium access control) protocol. Furthermore, not robust against selective jamming attacks. This article proposes CRAM: time-synchronized cryptographic frequency hopping protocol designed for LoRa physical layer. CRAM reduces contention by fairly exploiting available space maximizes entropy channel algorithm. We develop large testbed simulator thoroughly evaluate proposed Our evaluations show significantly improves scalability increases utilization while making difficult perform compared standard