Age of Information Scaling in Large Networks with Hierarchical Cooperation

Given n randomly located source-destination (S- D) pairs on a fixed area network that want to communicate with each other, we study the age of information with a particular focus on its scaling as the network size n grows. We propose a three- phase transmission scheme that utilizes hierarchical cooperation between users along with mega update packets and show that an average age scaling of O(nα(h) log n) per-user is achievable where h denotes the number of hierarchy levels and α(h) = 1 / (3.2h+1) which tends to 0 as h increases such that asymptotically average age scaling of the proposed scheme is O(log n). To the best of our knowledge, this is the best average age scaling result in a status update system with multiple S-D pairs.