Average age of information for status update systems with an energy harvesting server
Shahab Farazi, Andrew G. Klein, Donald R. Brown · 2018
This paper investigates the age of information in a single-source status update system with energy constraints. Specifically, a source provides status updates to a destination through a server assumed to have a battery with finite capacity that is replenished by harvesting energy. Arrival times of the status updates at the source and energy units at the server are assumed to be random according to independent Poisson processes. Service times are also assumed to be exponentially distributed and independent of the status and energy arrivals. The server is assumed to always be able to harvest energy when no information packet from the source is in service and the battery is not full. With regards to harvesting energy while packets are in service, this paper analyzes the average age of information both for servers that are able or unable to perform simultaneous service and energy harvesting. Closed-form expressions for the average age in terms of the system parameters are derived. Simulation results confirm the analysis and numerically demonstrate the performance advantage of servers with simultaneous service and energy harvesting.