Age of Information-Reliability Trade-offs in Energy Harvesting Sensor Networks

Abstract: Age of Information (AoI) is a recently defined quantity, which measures the freshness of information in a communication scheme. In this paper, we analyze a network that consists of a sensor node, an energy source and a receiver. The energy source is broadcasting energy and the sensor is charging its battery using energy-harvesting technologies. Whenever the battery gets fully charged, the sensor measures some quantity (called its status) from an environment, and (or) transmits its status to the receiver. The full analysis of AoI of this network, in the setting when each status is sent once, is given previously. However, that approach does not present a reliability guarantee better than the success probability of one transmission. In this paper, we present a closed form expression for the AoI of a deterministic and a randomized scheme that guarantee a desired probability of successful transmission for each status, alongside with a zero-error scheme. Furthermore, we define a novel notion called AoI-reliability trade-off and present the AoI-reliability trade-offs of our schemes. Additionally, we show that numerical results match our theoretical findings.