Energy and Spectral Efficient Scheduling for Heterogeneous IoT Sensor Nodes

With adaptive transmission, the throughput and power can be adapted to the channel conditions, which leads to a variable amount of energy consumption for the Internet of Things (IoT) sensor nodes. Considering an IoT network with heterogeneous sensor nodes in terms of their battery levels, we propose three channel adaptive schemes: the energy efficient scheme (EES), the spectral efficient scheme (SES), and the hybrid scheme (HS). One of the main novelties of this work is the proposed hybrid scheme which takes into consideration the remaining battery level in the IoT sensor node when deciding on the transmit power and the modulation mode at every transmission. Analytical results are provided in terms of the average spectrum efficiency (ASE), power usage ratio (PUR), and delay performance. Selected numerical results are presented to illustrate and validate the analytical results.