Reservation Dynamic Frame Slotted-ALOHA for wireless M2M networks with energy harvesting

We consider a wireless Machine-to-Machine (M2M) area network where a gateway periodically collects data from a group of end-devices equipped with energy harvesters. While the use of energy harvesters ideally provides infinite lifetime, the unpredictable amount of harvested energy may not guarantee that all data transmissions can be done in due time because of temporary energy shortages. We propose in this paper the Energy Harvesting-aware Reservation Dynamic Frame Slotted-ALOHA (EH-RDFSA) protocol as a solution suitable for managing the access of end-devices that transmit bursts of data packets while taking into account the energy availability. We derive a model based on a discrete-time Markov chain to analyze the evolution of the energy available in an end-device and to evaluate the performance of the network. In particular, we compute the data delivery ratio, which measures the ability of the protocol to successfully transmit data to the gateway without depleting the energy reserves of the end-devices, and the time efficiency, which measures the amount of data that can be transmitted in a given period of time. We have validated the accuracy of the analysis by means of computer-based simulations. Results show that the overall performance is influenced by the energy harvesting rate and the amount of data to transmit from each end-device. Finally, we have compared the performance of EH-RDFSA with that of DFSA and Time Division Multiple Access (TDMA) protocols.