Distributed IoT Communications With LEO Satellites: QoS Performance and Terminal Attempt Rate Schemes

Low Earth Orbit (LEO) satellites are increasingly being used to provide connectivity for wide area Internet of Things (IoT) sensing applications. Distributed IoT terminals are not able to coordinate their uplink transmissions to the nano-satellites, and so operate in a grant-free mode. Quality-of-Service (QoS) depends on the transmission attempt success statistics, which are time-varying. This paper presents asymptotic analysis results that characterize the IoT terminal's transmission success process. We show that it converges to an inhomogeneous Poisson process, in the large population regime, and characterize the time-dependent intensity as a function of the terminal location and the attempt rate scheme. We also propose three terminal attempt rate schemes that are solutions to max-min optimization problems. The performance of the proposed schemes are compared in terms of individual terminal QoS as well as the population-wide QoS distribution. Performance for various IoT applications is also presented.