  The Narrowband Internet of Things (NB-IoT) is a cellular technology
introduced by the Third Generation Partnership Project (3GPP) to provide
connectivity to a large number of low-cost IoT devices with strict energy
consumption limitations. However, in an ultra-dense small cell network
employing NB-IoT technology, inter-cell interference can be a problem, raising
serious concerns regarding the performance of NB-IoT, particularly in uplink
transmission. Thus, a power allocation method must be established to analyze
uplink performance, control and predict inter-cell interference, and avoid
excessive energy waste during transmission. Unfortunately, standard power
allocation techniques become inappropriate as their computational complexity
grows in an ultra-dense environment. Furthermore, the performance of NB-IoT is
strongly dependent on the traffic generated by IoT devices. In order to tackle
these challenges, we provide a consistent and distributed uplink power
allocation solution under spatiotemporal fluctuation incorporating NB-IoT
features such as the number of repetitions and the data rate, as well as the
IoT device's energy budget, packet size, and traffic intensity, by leveraging
stochastic geometry analysis and Mean-Field Game (MFG) theory. The
effectiveness of our approach is illustrated via extensive numerical analysis,
and many insightful discussions are presented.
