Optimizing Information Freshness in Random Access Channels

Yavaşcan, Orhan Tahir
In this work, a number of transmission strategies aimed at optimizing information freshness in random access channels are developed and studied. Threshold-ALOHA, an age-aware modification of slotted ALOHA, suggests a fixed age threshold on the terminals before they can become active and attempt transmissions with a constant probability. Threshold ALOHA nearly halves the average Age of Information (AoI) whilst the loss of throughput compared to slotted ALOHA is less than one percent. Mumista, multiple mini slotted threshold Aloha, is a further iteration of threshold Aloha that introduces mini slots before each data slot to enable a reservation based mechanism and improve throughput. The set of parameters that achieve the optimal throughput has been explicitly derived. Under ideal conditions, Mumista can approach theoretical limits of throughput and average age of information as closely as desired. Finally, we investigate the optimality of the threshold policy in a wireless energy transfer setting with a Gilbert-Elliott channel between a single transmitter and receiver pair. We obtain the optimal parameters in closed form.


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Citation Formats
O. T. Yavaşcan, “Optimizing Information Freshness in Random Access Channels,” M.S. - Master of Science, Middle East Technical University, 2022.