  Grant free access, in which each Internet of Things (IoT) device delivers its
packets through a randomly selected resource without spending time on
handshaking procedures, is a promising solution for supporting the massive
connectivity required for IoT systems. In this paper, we explore grant free
access with multi packet reception capabilities, with an emphasis on ultra low
end IoT applications with small data sizes, sporadic activity, and energy usage
constraints. We propose a power allocation scheme that integrates the IoT
device's traffic and energy budget by using a stochastic geometry framework and
meanfield game theory to model and analyze mutual interference among active IoT
devices.We also derive a Markov chain model to capture and track the IoT
device's queue length and derive the successful transmission probability at
steady state. Simulation results illustrate the optimal power allocation
strategy and show the effectiveness of the proposed approach.
