Relative Age of Information: Maintaining Freshness while Considering the Most Recently Generated Information

A queueing system handling a sequence of message arrivals is considered where each message obsoletes all previous messages. The objective is to assess the freshness of the latest message/information that has been successfully transmitted, i.e., "age of information" (AoI). We study a variation of traditional AoI, the "Relative AoI", here defined so as to account for the presence of newly arrived messages/information to the queue to be transmitted.