Threshold ALOHA with sensing data lookup in low-duty-cycle wireless networks

Abstract

Slotted ALOHA is a well-known multiple access control protocol that devices use to access a radio channel in wireless networks. Age of information (AoI) is a key network performance indicator that represents the elapsed time between the time data is generated and the time data is received. Threshold-based ALOHA, a variant of the slotted ALOHA, uses a threshold and a transmission probability to send data and meet its requirement of average AoI (AAoI), in which however energy consumption is not discussed. It is crucial that a device operates energy-efficiently to reduce energy consumption, which is conducive to extending the life of the device and reducing greenhouse gas emissions. Therefore, this paper proposes a modified threshold ALOHA in low-duty-cycle wireless networks, called LBG-threshold-ALOHA, in which a device looks up whether sensing data is generated in prior N slots before its data generation/transmission. Instead of generating data in each transmission, the LBG-threshold ALOHA uses data generated in prior N slots to send, which reduces the activity of data generation and thus yields lower energy consumption. The characteristic of lower energy consumption is beneficial to produce a lower AAoI on a network constrained by low energy consumption. Simulation results show that, under an upper limit on the mean energy consumption, the LBG-threshold-ALOHA yields a lower minimum AAoI compared to the original threshold ALOHA.