Information freshness is crucial in a wide range of wireless applications where a destination needs the most recent measurements of a remotely observed random process. In this paper, we study the information freshness of a single-server multi-source M/M/1 queueing model under a first-come first-served (FCFS) serving policy. The information freshness of the status updates of each source is evaluated by the average age of information (AoI). We derive an exact expression for the average AoI for the multi-source M/M/1 queueing model. Simulation results are provided to validate the derived exact expression for the average AoI.
Funding Agencies|Infotech Oulu; Academy of FinlandAcademy of FinlandEuropean Commission [319485, 323698]; Academy of Finland 6Genesis Flagship [318927]; European Unions Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant [793402]; Finnish Foundation for Technology Promotion; Riitta ja Jorma J. Takanen Foundation; HPY Research Foundation